Dust collection system

Abstract

To enable compactification and weight reduction of an impact tool even in a structure where a dust collection attachment is slid in a linear direction to be attached to a housing of the impact tool.SOLUTION: In a dust collection system S, a dust collection attachment 90 is slid in a vertical direction relative to a housing 2 of a hammer drill 1 to cause a recessed side engagement part provided at the housing 2 and a protruding side engagement part provided at the dust collection attachment 90 to be engaged with and attached to each other. The protruding side engagement part and the recessed side engagement part are separated from each other in a vertical direction and include an upper engagement part 42 and an upper projection 125 which are engaged with each other in an attachment state of the dust collection attachment 90, and a lower engagement part 55 and a lower projection 126 which are engaged with each other in the attachment state.SELECTED DRAWING: Figure 16

Description

Technical Field

[0001] The present disclosure relates to a dust collection system in which a dust collection attachment is attached to a percussion tool such as a hammer drill.

Background Art

[0002] In a percussion tool such as a hammer drill, a dust collection attachment for collecting and storing dust generated from a workpiece during a drilling operation or the like may be attached. In this dust collection system including the percussion tool and the dust collection attachment, as an attachment structure of the dust collection attachment, for example, Patent Documents 1 and 2 disclose inventions in which vertical guide grooves are formed on the outer surface of the housing of the percussion tool, and rail portions that fit into the guide grooves are formed vertically on the dust collection attachment. With this structure, the dust collection attachment can be attached by sliding it relative to the percussion tool in the vertical direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional dust collection system, in order to reduce rattling of the dust collection attachment in the attached state, it is desirable to form the rail portion long. However, in this case, it is also necessary to form the guide groove long on the housing side of the percussion tool in accordance with the rail portion. For this reason, it is necessary to change the shape of the housing to ensure the length of the guide groove, which hinders downsizing and weight reduction.

[0005] Therefore, an object of the present disclosure is to provide a dust collection system that can maintain the compactness and weight reduction of a percussion tool even with a structure in which a dust collection attachment is slid linearly and attached to the housing of the percussion tool.

Means for Solving the Problems

[0006] To achieve the above object, the present disclosure provides a percussion tool having a housing that houses a motor, and a percussion mechanism unit provided in the housing and capable of being struck by a striker that reciprocates a tip tool attached to the front end, and a dust collection system including a dust collection attachment attached to the housing, wherein the dust collection attachment is slid relative to the housing in a up and down direction so that a a pair of left and right convex engagement portion provided on either the housing or the dust collection attachment and a a pair of left and right concave engagement portion provided on the other can be engaged with each other and attached, and a pair of the convex engagement portion and a pair of the concave engagement portion are each up and down separated into a plurality in a on the upper side direction and engaged with each other in the attached state of the dust collection attachment, a pair of including at least a first convex engagement portion and a pair of a first concave engagement portion that are engaged with each other in the attached state, and on the lower side a second convex engagement portion and a pair of a second concave engagement portion that are engaged with each other in the attached state, a pair of characterized in that. and The left - right widths of the pair of the first convex - side engaging portions and the pair of the first concave - side engaging portions that engage with each other on the upper side are smaller than the left - right widths of the pair of the second convex - side engaging portions and the pair of the second concave - side engaging portions that engage with each other on the lower side, The pair of the first convex - side engaging portions and the pair of the first concave - side engaging portions on the upper side and the pair of the second convex - side engaging portions and the pair of the second concave - side engaging portions on the lower side have different positions in the front - rear direction

Advantages of the Invention

[0007] ​According to the present disclosure, since the convex engagement portion and the concave engagement portion are separated in the linear direction, the dust collection attachment can be attached without rattling even if the convex engagement portion and the concave engagement portion are not formed long. For this reason, it is not necessary to change the shape of the housing of the impact tool, and it is possible to maintain the compactness and weight reduction.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Mode for Carrying Out the Invention

[0009] In one embodiment of the present disclosure, the first convex-side engaging portion and the first concave-side engaging portion, and the second convex-side engaging portion and the second concave-side engaging portion may each be provided in a pair on the left and right. According to this configuration, the dust collection attachment can be attached in a well-balanced manner, and rattling in the left-right direction of the dust collection attachment in the attached state can be effectively suppressed. In one embodiment of the present disclosure, the pair of first convex-side engaging portions and first concave-side engaging portions, and the pair of second convex-side engaging portions and second concave-side engaging portions may have different left-right widths from each other. According to this configuration, the left-right arrangement of the engaging portions according to the shape of the housing becomes possible. In one embodiment of the present disclosure, the linear direction is the vertical direction, and the left-right width of the pair of first convex-side engaging portions and first concave-side engaging portions that engage with each other on the upper side may be smaller than the left-right width of the pair of second convex-side engaging portions and second concave-side engaging portions that engage with each other on the lower side. According to this configuration, the left-right arrangement of the engaging portions according to the shapes of the upper and lower housings that are different from each other becomes possible. In one embodiment of the present disclosure, the first convex-side engaging portion and the first concave-side engaging portion, and the second convex-side engaging portion and the second concave-side engaging portion may have different positions in the front-rear direction from each other. According to this configuration, the front-rear arrangement of the engaging portions according to the shape of the housing becomes possible.

[0010] In one embodiment of the present disclosure, when the dust collection attachment is slid relative to the housing in the linear direction for attachment, either one of the first convex-side engaging portion and the first concave-side engaging portion, and the second convex-side engaging portion and the second concave-side engaging portion may engage with the other one earlier. According to this configuration, the convex-side engaging portion and the concave-side engaging portion that engage earlier guide the other convex-side engaging portion and concave-side engaging portion smoothly to their respective engagement positions. In one embodiment of the present disclosure, at a predetermined position where the dust collection attachment is brought into contact with the housing before being slid relatively in a linear direction, the first convex-side engaging portion, the first concave-side engaging portion, the second convex-side engaging portion, and the second concave-side engaging portion may be located on the same straight line in the linear direction. According to this configuration, alignment of the respective engaging portions can be easily performed, and subsequent attachment of the dust collection attachment can be performed smoothly. In one embodiment of the present disclosure, a third convex-side engaging portion extending in the striking axis direction of the striking mechanism portion may be provided on either the housing or the dust collection attachment, and a third concave-side engaging portion that engages with the third convex-side engaging portion in the attached state of the dust collection attachment to the housing may be provided on the other. According to this configuration, rattling of the dust collection attachment in the left-right direction can be more effectively suppressed, and the integrality of the housing and the dust collection attachment is enhanced.

[0011] In one embodiment of the present disclosure, the dust collection attachment may have a protruding portion located below the housing in the attached state to the housing 2, and a hook portion that locks to the housing in the attached state may be provided on the protruding portion. According to this configuration, detachment of the dust collection attachment from the housing is restricted, and the dust collection attachment does not accidentally shift or come off. In one embodiment of the present disclosure, a dust collection fan may be arranged below the motor, and an air intake port for sucking air by the rotation of the dust collection fan may be provided on the lower surface of the housing. According to this configuration, even if a dust collection fan is provided, it is not necessary to increase the diameter of the housing portion of the motor in the radial direction, and compactness can be maintained. Further, it becomes difficult for foreign matters such as dust to enter from the air intake port, and a wide opening area can be secured. In one embodiment of the present disclosure, a shutter for closing the air intake port in a state where the dust collection attachment is not attached may be provided on the lower surface of the housing, and a pressing member for moving the shutter to the open position of the air intake port in the attached state to the housing may be provided on the protruding portion. According to this configuration, even if an air intake port is provided, dustproofness and waterproofness of the striking tool can be ensured. Further, the shutter can be surely opened by the pressing member simultaneously with the attachment of the dust collection attachment. In one embodiment of the present disclosure, in the dust collection attachment, a slide portion having a suction port at the front end may be disposed at a position offset to either the left or the right from the center in the left-right direction. According to this configuration, even if there is a slide portion, the dust collection attachment can be attached to the front of the housing.

Example

[0012] Hereinafter, examples of the present disclosure will be described with reference to the drawings. (Description of the hammer drill) FIG. 1 is a perspective view from below of a hammer drill which is an example of a percussion tool, FIG. 2 is a side view, FIG. 3 is a plan view, and FIG. 4 is a central longitudinal sectional view of the hammer drill. The hammer drill 1 includes a housing 2 that forms an outer shell. The housing 2 includes a main body housing 3, a rear housing 4, and a front housing 5. The main body housing 3 houses a motor 6 at the lower part and connects the front housing 5 at the upper part. The motor 6 is housed in a posture with the rotation shaft 7 directed in the vertical direction. A pinion 8 is attached upward at the upper end of the rotation shaft 7. The main body housing 3 is formed by screwing together the left and right half housings 3a, 3b. A plurality of upper air inlets 3c, 3c... are formed on the upper surface of the main body housing 3.

[0013] The rear housing 4 includes a grip portion 9 extending in the vertical direction and is connected to the main body housing 3 in a loop shape. The rear housing 4 is formed by screwing together the left and right half housings 4a, 4b. A switch 10 with a trigger 11 protruding forward is provided at the upper part of the grip portion 9. A battery mounting portion 12 is formed at the lower part of the grip portion 9. A battery pack 13 is slidably mounted in the battery mounting portion 12 from the rear. A terminal block 14 electrically connected to the battery pack 13 is held in the battery mounting portion 12. A controller 15 is housed above the terminal block 14.

[0014] The front housing 5 is cylindrical and includes a rear cylindrical portion 16 and a front cylindrical portion 17. The rear cylindrical portion 16 has a substantially rectangular cross-section extending in the vertical direction and is screwed to the upper part of the main body housing 3 from the front. The front cylindrical portion 17 has a circular cross-section and projects forward from an eccentric position above the rear cylindrical portion 16. On the left side surface of the rear cylindrical portion 16, an operation mode switching knob 18 is provided. Inside the upper part of the main body housing 3, an inner housing 19 assembled to the rear cylindrical portion 16 is provided. Inside the front housing 5 and the inner housing 19, a striking mechanism portion 20 is provided. In the striking mechanism portion 20, an intermediate shaft 21 and a tool holder 22 are provided in the front-rear direction respectively. The intermediate shaft 21 is rotatably supported inside the lower side of the front housing 5 and the inner housing 19. On the intermediate shaft 21, a first gear 23, a boss sleeve 24, a clutch 25, and a second gear 26 are provided from the rear. The pinion 8 of the rotating shaft 7 penetrates the inner housing 19 from below and is supported by a bearing 27 and meshes with the first gear 23.

[0015] The tool holder 22 is cylindrical and is rotatably supported coaxially with the front cylindrical portion 17 above the intermediate shaft 21. A third gear 28 is provided in the middle part of the tool holder 22. The third gear 28 meshes with the second gear 26 of the intermediate shaft 21. The front end of the tool holder 22 projects forward from the front cylindrical portion 17. An operation sleeve 29 to which a bit can be detachably attached is provided at the front end of the tool holder 22. A piston cylinder 30 is loosely inserted into the rear part of the tool holder 22 so as to be movable back and forth. An arm 31 is connected to the rear end of the piston cylinder 30. The arm 31 is externally fitted to the boss sleeve 24 via a swash bearing with an inclined axis and can swing back and forth. Inside the piston cylinder 30, a striker 33 is accommodated so as to be movable back and forth via an air chamber 32. An impact bolt 34 is provided inside the tool holder 22 in front of the piston cylinder 30.

[0016] Below the front housing 5 in the main body housing 3, a cylindrical motor housing portion 35 is formed. A motor 6 is housed in the motor housing portion 35. The motor 6 is a brushless motor including a stator 36 and a rotor 37 having a rotating shaft 7. The lower portion of the rotating shaft 7 passes through a bearing holding portion 38 formed in the motor housing portion 35 and is supported by a bearing 39. In front of the bearing holding portion 38 and on the front surface of the motor housing portion 35, a light 40 for irradiating the front of the tool holder 22 is provided. On the left and right of the light 40 and extending from the front surface to the side surface of the motor housing portion 35, a pair of chamfered portions 41, 41 are formed. Above the chamfered portions 41, 41, a pair of upper engaging portions 42, 42 are formed. Each upper engaging portion 42 is cut into the outer surface of the motor housing portion 35 upward from the chamfered portion 41 and has a groove shape with an open side surface and bottom surface. The lower portion of each upper engaging portion 42 has a tapered shape with the groove width widening downward. The upper engaging portions 42, 42 are for attaching a dust collecting attachment 90 described later. Above the upper engaging portions 42, 42 and at the left and right centers of the lower surface of the rear cylinder portion 16, an engaging groove 43 extending in the front-rear direction is formed. The front end of the engaging groove 43 is open forward.

[0017] Below the motor housing portion 35, a fan housing portion 45 is formed. As shown in FIG. 5, the fan housing portion 45 is partitioned and formed in the main body housing 3 by an upper plate portion 46 and a rear plate portion 47 from the motor housing portion 35 and the battery mounting portion 12. The upper plate portion 46 is a plate-shaped member in the front-rear and left-right directions for partitioning the inside of the main body housing 3 vertically. On the upper surface of the upper plate portion 46, a bearing holding portion 38 is integrally formed. The rear plate portion 47 extends downward from the rear end of the upper plate portion 46 and is a plate-shaped member in the up-down and left-right directions for partitioning the inside of the main body housing 3 front-rear. The lower end of the rotating shaft 7 penetrates the upper plate portion 46 and protrudes into the fan housing portion 45. Inside the fan housing portion 45, a double fan 48 is orthogonally attached to the lower end of the rotating shaft 7. The double fan 48 is formed with a motor cooling fan 50 on the upper side and a dust collecting fan 51 on the lower side, with a partition plate 49 that is circular in plan view as a boundary. Both fans 50 and 51 are centrifugal fans. The upper ends of the fins 50a of the motor cooling fan 50 are close to the upper plate portion 46. A cover 52 that covers each fin 51a from below is provided below the dust collecting fan 51, except for the central portion. Two ring-shaped upper ribs 53, 53 are formed downward on the inner peripheral edge of the cover 52 and on the outer side in the radial direction thereof, concentrically. Above the motor cooling fan 50, upper ventilation openings 54, 54 that open before and after the bearing holding portion 38 are formed in the upper plate portion 46 in the left-right direction.

[0018] As also shown in FIG. 6, the fan housing portion 45 is formed with a larger left-right width than the motor housing portion 35. The front surface of the fan housing portion 45 also protrudes forward from the front surface of the motor housing portion 35. The left-right width of the fan housing portion 45 is substantially equal to the left-right width of the battery mounting portion 12 and the battery pack 13. At positions near the front surface on the left and right side surfaces of the fan housing portion 45, a pair of left and right lower engaging portions 55, 55 are formed. The lower engaging portions 55, 55 are cut from the lower surface of the fan housing portion 45 upward, and are in a groove shape that opens the side surface and the lower surface. The lower engaging portions 55, 55 are also for attaching the dust collecting attachment 90. The lower engaging portions 55, 55 are parallel to the upper engaging portions 42, 42, but the forming positions are in front of the upper engaging portions 42, 42 and on the left and right outer sides. At the lower parts of the left and right side faces of the fan housing portion 45, behind the lower engaging portions 55, 55, locking grooves 56, 56 extending in the front-rear direction are formed as shown in FIG. 7. At the rear parts of the locking grooves 56, 56, overhanging portions 57, 57 are formed where the left and right inner side faces at the back protrude toward the inside of the fan housing portion 45. Above and below each overhanging portion 57, slit-shaped side exhaust ports 58, 58 that communicate the inside of the fan housing portion 45 with the inside of the locking groove 56 are formed. As shown in FIG. 6, the left and right lower side faces of the fan housing portion 45 where the locking grooves 56, 56 are formed are tapered surfaces whose left and right widths become narrower as they go downward.

[0019] Below the double fan 48 within the fan housing portion 45, a baffle plate 60 is provided. As shown in FIGS. 8 and 9, the baffle plate 60 has a substantially circular shape in a front view on the front side and a substantially square shape in a front view on the rear side. At the center of the substantially circular portion of the baffle plate 60, a circular lower ventilation port 61 is formed. On the inner peripheral edge of the lower ventilation port 61 and on the outer side in its radial direction, two ring-shaped lower ribs 62, 62 are formed upward in concentric circles. On the lower surface of the baffle plate 60, a lower cylindrical portion 63 that is coaxial with the lower ventilation port 61 and has a larger diameter than the lower ventilation port 61 is formed downward. At the front end of the baffle plate 60, a locking piece 64 that protrudes forward is formed. On the left side of the locking piece 64, a semi-cylindrical portion 65 that rises upward is formed. The semi-cylindrical portion 65 is formed in a posture with the open side facing the outer side in the radial direction of the baffle plate 60.

[0020] Inside the fan housing portion 45, receiving ribs 66 of the baffle plate 60 are formed. As shown in FIG. 10, the receiving ribs 66 are formed in a manner that encircles the rear part, left and right, and the outer peripheral edge of the front right side of the baffle plate 60 above the left and right locking grooves 56, 56. The left and right and the front right side of the receiving ribs 66 project from the inner surface of the fan housing portion 45. The left side of the receiving ribs 66 is connected to a bulging portion 67 that bulges inside the fan housing portion 45 to form the lower engaging portion 55. Above the bulging portion 67, a plurality of vertical ribs 68, 68·· are formed in the vertical direction. The front right side of the receiving ribs 66 is formed up to the right side of the locking piece 64 of the baffle plate 60. The rear part of the receiving rib 66 is formed at the upper end of a partition wall 69 that is raised upward from the bottom surface of the fan housing portion 45 in front of the rear plate portion 47. The partition wall 69 partitions the inside of the fan housing portion 45 into front and rear parts below the double fan 48. A bottom exhaust port 70 extending in the left - right direction is formed on the bottom surface of the fan housing portion 45 behind the partition wall 69. A groove 71 for locking the locking piece 64 is formed on the inner surface of the front part of the fan housing portion 45.

[0021] A circular hole 72 is formed on the bottom surface of the fan housing portion 45 in front of the bottom exhaust port 70. The circular hole 72 is formed coaxially and with substantially the same diameter as the lower cylindrical portion 63 of the baffle plate 60. A cap 73 is fitted into the circular hole 72 from the inside. A shutter 74 and a coil spring 75 are interposed between the cap 73 and the baffle plate 60. The cap 73 has a fitting portion 76 on its lower surface that fits into the circular hole 72. A circular lower intake port 77 is formed at the center of the fitting portion 76. On the outer periphery of the cap 73, a peripheral wall portion 78 into which the lower end of the lower cylindrical portion 63 of the baffle plate 60 is inserted and fitted is formed. The shutter 74 has a central disc portion 80, an outer ring portion 81, and a cross rib 82 connecting the disc portion 80 and the ring portion 81. The disc portion 80 has a larger diameter than the lower intake port 77 of the cap 73, and a circular protrusion 83 protruding downward is provided at the center of the lower surface. The ring portion 81 has an inner diameter larger than the outer diameter of the disc portion 80 and is arranged concentrically with the disc portion 80. The ring portion 81 has a smaller diameter than the inner diameter of the lower cylindrical portion 63 and can be fitted inside the peripheral wall portion 78 of the cap 73. The cross rib 82 is arranged concentrically on the upper surfaces of the disc portion 80 and the ring portion 81 and connects the two. Therefore, four arcuate through - holes 84, 84·· are formed at equal intervals in the circumferential direction between the disc portion 80 and the ring portion 81. The coil spring 75 is housed inside the lower cylindrical portion 63. The lower end of the coil spring 75 abuts on the upper surface of the ring portion 81 outside the cross rib 82 of the shutter 74. The upper end of the coil spring 75 abuts on the lower surface of the baffle plate 60.

[0022] In the fan housing portion 45, first, the baffle plate 60 holding the shutter 74 and the coil spring 75 and the cap 73 are assembled between the receiving rib 66 of the left half housing 3a and the bottom surface of the fan housing portion 45. At this time, the baffle plate 60 abuts the semi-cylindrical portion 65 against the vertical ribs 68, 68 on the left bulging portion 67 and locks the locking piece 64 in the groove 71. When the right half housing 3b is assembled in this state, due to the repulsive force of the coil spring 75, the baffle plate 60 is biased to a position where the left, right, and rear portions abut the receiving rib 66 from below. At the same time, the shutter 74 is biased downward together with the cap 73. Therefore, the cap 73 is pressed to a position where the fitting portion 76 fits into the circular hole 72, and the shutter 74 is pressed to a position where the disk portion 80 closes the lower intake port 77. In this state, the lower ribs 62, 62 of the baffle plate 60 and the upper ribs 53, 53 of the cover 52 of the dust collecting fan 51 overlap each other alternately in the radial direction without contact. Therefore, a labyrinth is formed between the dust collecting fan 51 and the baffle plate 60. Thus, the baffle plate 60 positioned by the receiving rib 66 divides the inside of the fan housing portion 45 into an upper space A1 and a lower space A2 as shown in FIGS. 5 and 6. The upper space A1 communicates with the rear of the partition wall 69 and the bottom exhaust port 70. The lower space A2 is formed in front of the partition wall 69 and communicates with the left and right side exhaust ports 58, 58. However, a communication port 85 (FIG. 10) that communicates the upper space A1 and the lower space A2 is formed between the locking piece 64 and the semi-cylindrical portion 65.

[0023] Thus, a motor cooling flow path R1 is formed by the rotation of the fan 50 for cooling the motor of the double fan 48 in the main body housing 3. In the motor cooling flow path R1, the air sucked in from the upper intake port 3c on the upper surface of the main body housing 3 passes between the main body housing 3, the front housing 5, and the inner housing 19 and the motor 6 as shown by the dotted arrow in FIG. 5. Thereafter, the air enters the upper space A1 of the fan housing portion 45 from the upper ventilation port 54 and is discharged from the bottom exhaust port 70. On one hand, within the fan housing portion 45, the rotation of the dust collection fan 51 of the double fan 48 forms the dust collection flow path R2 on the machine side. In the dust collection flow path R2 on the machine side, with the shutter 74 rising against the biasing force of the coil spring 75 and opening the lower air intake 77, as indicated by the dashed-dotted arrow in FIG. 5, the air sucked into the lower space A2 from the lower air intake 77 passes through the through holes 84 of the shutter 74, the lower cylindrical portion 63 of the baffle plate 60, and the lower vent 61 and enters the upper space A1. Similar to the motor cooling flow path R1, it flows from the radially outer side of the dust collection fan 51 to the bottom exhaust port 70. However, the motor cooling flow path R1 and the dust collection flow path R2 on the machine side are provided with a branch flow path R3. In the branch flow path R3, a part of the air that has entered the upper space A1 enters the lower space A2 from the radially outer side of the double fan 48 through the communication port 85 as indicated by the two-dotted chain line arrow in FIG. 5, and is discharged from the side exhaust ports 58, 58 through the outer periphery of the lower cylindrical portion 63 of the baffle plate 60.

[0024] (Description of the dust collection attachment) FIG. 11 is a perspective view showing an example of a dust collection attachment (hereinafter simply referred to as an "attachment"). FIG. 12 is a side view of the attachment, FIG. 13 is a plan view, and FIG. 14 is a central longitudinal sectional view of the attachment. The attachment 90 includes a casing 91 in an L shape in side view. The casing 91 is formed by assembling the left and right half casings 91a, 91b. A main body portion 92 provided with a dust box 93 is provided on the front side of the casing 91. A protruding portion 94 protruding rearward from the lower part of the main body portion 92 is provided on the rear side of the casing 91. A slide portion 95 protruding forward is provided on the upper left part of the main body portion 92.

[0025] The casing 91 includes a front top plate 96 forming the upper surface of the main body 92, a rear top plate 97 forming the upper surface of the protruding portion 94, a bottom plate 98 forming the lower surfaces of the main body 92 and the protruding portion 94, a pair of side plates 99, 99 forming the side surfaces of the main body 92 and the protruding portion 94, a front back plate 100 forming the rear surface of the main body 92, and a rear back plate 101 forming the rear surface of the protruding portion 94. The front of the main body 92 is open, and the dust box 93 is detachable into the main body 92 from the front. The slide portion 95 includes a slide cylinder 102 and a flexible hose 103. The slide cylinder 102 is held movably back and forth by a guide fitting 104 provided on the front top plate 96. A nozzle 105 having a suction port 106 is orthogonally attached to the tip of the slide cylinder 102. The suction port 106 is located at the center in the left-right direction above the main body 92.

[0026] The flexible hose 103 is loosely inserted into the slide cylinder 102, and the front end is connected to the base end of the nozzle 105. The rear end of the flexible hose 103 is connected to the upstream end of a duct 107 protruding from the left rear portion of the main body 92. The flexible hose 103 integrally includes a spiral wire and is compressed between the nozzle 105 and the duct 107 to bias the slide cylinder 102 forward. The forward and backward positions of the slide cylinder 102 can be regulated by stoppers 108, 108 provided on the side surface of the slide cylinder 102. The downstream end of the duct 107 opens into the main body 92 and communicates with an inlet (not shown) provided in the dust box 93. The dust box 93 includes a lid 109 provided with a filter 110, and a box body 111 hinged to the lid 109 to cover the filter 110 from the front. The dust box 93 is attached by engaging the lower surface of the box body 111 with a receiving shaft 112 provided at the front end of the bottom plate 98, and elastically locking a latching piece 113 protruding forward from the lid 109 to the front end of the front top plate 96. An outlet 114 for the air that has passed through the filter 110 is provided at the lower part of the lid 109. A vibration generator 115 is provided on the front surface of the box body 111. The vibration generator 115 is for generating vibrations in the box body 111 by a rotational operation to remove the dust adhering to the filter 110.

[0027] An exhaust pipe 116 with its front end connected to the outlet 114 is provided on the protruding portion 94. The exhaust pipe 116 is in the shape of an angular cylinder that extends rearward within the protruding portion 94 and then bends upward. An exhaust port 117 is formed on the upper surface of the rear end of the exhaust pipe 116. A rubber cap 118 is placed over the exhaust port 117. The rubber cap 118 has a tapered seal portion 119 with a smaller diameter as it goes upward at the upper part. An opening 120 that is coaxial with and substantially the same diameter as the exhaust port 117 is formed at the center of the seal portion 119. The rubber cap 118 is fitted into a round hole 121 provided in the rear top plate 97 above the exhaust port 117. The seal portion 119 protrudes upward from the round hole 121. A pin 122 protruding upward is provided inside the rear end of the exhaust pipe 116 below the exhaust port 117. The pin 122 passes through the centers of the exhaust port 117 and the opening 120 of the rubber cap 118 and protrudes above the rubber cap 118. In this way, an attachment-side dust collection flow path R4 indicated by a one-dot chain line arrow in FIG. 14 is formed in the attachment 90. In the attachment-side dust collection flow path R4, the air that has entered from the suction port 106 enters the dust box 93 from the nozzle 105 through the flexible hose 103 and the duct 107. Then, after passing through the filter 110, the air enters the exhaust pipe 116 from the outlet 114 and is discharged upward from the exhaust port 117.

[0028] On the upper surface of the front top plate 96, a step is formed where the rear part is lower than the front part. On the rear part of the front top plate 96, the lower surface of the rear cylinder part 16 of the front housing 5 of the hammer drill 1 can be placed. At the center in the left - right direction of the rear part, an engaging rail 123 projects in the front - rear direction. The engaging rail 123 corresponds to the engaging groove 43 provided on the lower surface of the rear cylinder part 16. The rear edge of the front top plate 96 has a curved shape that matches the motor housing part 35 of the hammer drill 1. The upper rear ends of the left and right side plates 99, 99 connected to the rear edge of the front top plate 96 are a pair of arm parts 124, 124 whose left - right width is narrower than that of the front part and the lower part of the side plates 99, 99. The left - right width of the arm parts 124, 124 is slightly larger than the left - right width of the upper part of the motor housing part 35. On the opposing surfaces of the arm parts 124, 124 facing each other, upper ridges 125, 125 that fit into the upper engaging parts 42, 42 provided on the motor housing part 35 are formed in the vertical direction. Below the upper ridges 125, 125, the left - right width of the left and right side plates 99, 99 is slightly larger than the left - right width of the fan housing part 45. On the opposing surfaces of the lower parts of the side plates 99, 99 below the upper ridges 125, 125, lower ridges 126, 126 that fit into the lower engaging parts 55, 55 provided on the fan housing part 45 are formed in the vertical direction. The lower ridges 126, 126 are located in front of the upper ridges 125, 125 in the same way as the front - rear positions of the upper engaging parts 42, 42 and the lower engaging parts 55, 55. On the front back plate 100, a plurality of ribs 127, 127 ··· whose rear surface has a curved shape matching the front surfaces of the motor housing part 35 and the fan housing part 45 are formed in the left - right direction at intervals in the vertical direction.

[0029] The left and right side plates 99, 99 in the protruding portion 94 protrude upward from the rear top plate 97. A pair of left and right notch portions 130, 130 are formed in a strip shape in the vertical direction on the side plates 99, 99. A pair of left and right hook plates 131, 131 are provided in the notch portions 130, 130. As shown in FIG. 15, each hook plate 131 is supported at its upper and lower ends so as to be swingable in the left-right direction by a support pin 132 installed in the front-rear direction within the notch portion 130. At the upper end of each hook plate 131, a claw portion 133 protruding inward is formed. The claw portion 133 has a return shape in which the upper surface is inclined downward as it goes toward the center on the left and right. Each hook plate 131 is rotationally biased by a torsion spring 134 held within the protruding portion 94 inside the support pin 132 so that the upper end swings inward. However, stopper portions 135, 135 (FIGS. 13 and 14) with which the front and rear side edges of the hook plate 131 abut are formed on the front and rear side edges of the notch portion 130. Therefore, in the normal state, the hook plates 131, 131 are rotationally restricted in a parallel posture with the side plates 99, 99 where the side edges of the upper ends abut against the stopper portion 135. In this parallel posture, the claw portions 133, 133 protrude inward from the side plates 99, 99. Finger-hooking portions 136, 136 are recessed on the outer surfaces of the hook plates 131, 131 below the support pins 132, 132.

[0030] (Description of the dust collection system) The attachment 90 is attached to the hammer drill 1. For this attachment, first, as shown in FIG. 16, the hammer drill 1 and the attachment 90 are arranged such that the protruding portion 94 is positioned below the fan housing portion 45, and the arm portions 124, 124 of the side plates 99, 99 are positioned below the upper engaging portions 42, 42 of the motor housing portion 35. Then, the rib 127 of the front back plate 100 of the attachment 90 is brought into contact with the front surface of the fan housing portion 45. At this set position, the upper protrusions 125, 125 are positioned directly below the upper engaging portions 42, 42, and at the same time, the lower protrusions 126, 126 are positioned directly below the lower engaging portions 55, 55. Also, the engaging rail 123 is positioned directly below the engaging groove 43. In this state, the rubber cap 118 and the pin 122 of the protruding portion 94 are positioned directly below the shutter 74 that closes the lower air inlet 77.

[0031] Slide the attachment 90 upward from here, or slide the hammer drill 1 downward. Then, the relatively moved upper ridges 125, 125 engage with the upper engaging portions 42, 42 from below, and the lower ridges 126, 126 engage with the lower engaging portions 55, 55 from below respectively. However, due to the difference in the vertical lengths, the engagement timing is different between the upper and lower parts. The lower ridges 126, 126 engage with the lower engaging portions 55, 55 before the upper ridges 125, 125 engage with the upper engaging portions 42, 42. Therefore, the upper ridges 125, 125 are smoothly guided to the engagement positions with the upper engaging portions 42, 42 by the lower ridges 126, 126 and the lower engaging portions 55, 55 that engage first. Even if there is some rattling here, the upper ridges 125, 125 are surely guided to the upper engaging portions 42, 42 by the tapered shape at the lower part of the upper engaging portions 42, 42. On the other hand, as the attachment 90 relatively moves, the engaging rail 123 also engages with the engaging groove 43 from below. When the upper ridge 125 abuts against the upper surface of the upper engaging portion 42, the lower ridge 126 abuts against the upper surface of the lower engaging portion 55, and the engaging rail 123 abuts against the lower surface of the front housing 5, the relative movement of the attachment 90 is restricted.

[0032] During the relative movement of this attachment 90, the hook plates 131, 131 of the protruding portion 94 expand left and right at the upper end against the biasing force of the torsion springs 134, 134 when the claw portions 133, 133 abut against the inclination of the lower side surface of the fan housing portion 45. Therefore, the relative movement of the attachment 90 is allowed. When the relative movement of the attachment 90 is restricted by the abutment of each engaging portion, at the same time, the claw portions 133, 133 reach the locking grooves 56, 56. Then, the hook plates 131, 131 return to the parallel posture by the biasing force of the torsion springs 134, 134. Therefore, as shown in FIG. 17, together with the engagement of each engaging portion, the claw portions 133, 133 are locked in the locking grooves 56, 56. On the one hand, as the attachment 90 moves relative to the hammer drill 1, the pin 122 that abuts against the circular protrusion 83 of the shutter 74 pushes up the shutter 74 against the biasing force of the coil spring 75. Therefore, as shown in FIG. 18, the lower air intake port 77 opens, and the sealing portion 119 of the rubber cap 118 abuts against the lower surface of the cap 73 and is elastically deformed to seal the space between the lower air intake port 77 and the exhaust port 117.

[0033] In this way, a dust collection system S is obtained in which the attachment 90 is attached to the hammer drill 1 in a state where its movement is restricted in the vertical, front-back, left-right directions. In this state, the attachment-side dust collection flow path R4 communicates with the main body-side dust collection flow path R2. When forming this dust collection system S, the attachment 90 at the set position in FIG. 16 may be relatively moved to the attachment positions in FIGS. 17 and 18. Therefore, the stroke of the relative movement of the attachment 90 during attachment can be short. Also, at the set position in FIG. 16 where the rib 127 of the front back plate 100 of the casing 91 is brought into contact with the front surfaces of the motor housing portion 35 and the fan housing portion 45 from the front, the upper engaging portion 42 and the upper ridge 125, the lower engaging portion 55 and the lower ridge 126, and the engaging groove 43 and the engaging rail 123 are in an aligned state on the same vertical line. Therefore, the alignment of the respective engaging portions can be easily performed, and subsequent attachment of the attachment 90 can be smoothly performed.

[0034] In the dust collection system S, the suction port 106 of the attachment 90 is pressed against the work surface of the workpiece, and the tip of the bit B (Fig. 18) is set into the suction port 106. In this state, the trigger 11 of the hammer drill 1 is pushed in. Then, the switch 10 turns ON and the controller 15 drives the motor 6. Thus, the rotary shaft 7 and the intermediate shaft 21 via the pinion 8 rotate. At this time, the clutch 25 is slid by operating the switching knob 18 provided on the side surface of the front housing 5. Then, it is possible to select any one of a forward position (drill mode) where the clutch 25 engages only with the second gear 26, a reverse position (hammer mode) where the clutch 25 engages only with the boss sleeve 24, and an intermediate position (hammer drill mode) where the clutch 25 engages with the second gear 26 and the boss sleeve 24 simultaneously. In the drill mode, the tool holder 22 rotates via the third gear 28 to rotate the bit B. In the hammer mode, the piston cylinder 30 reciprocates due to the swing of the arm 31. Thus, the striker 33 reciprocates in conjunction via the air chamber 32. Then, the striker 33 strikes the bit B via the impact bolt 34. In the hammer drill mode, the rotation of the tool holder 22 and the strike of the impact bolt 34 are performed simultaneously.

[0035] When the hammer drill 1 is advanced with the suction port 106 set, the slide cylinder 102 retreats together with the nozzle 105, and the bit B penetrates the suction port 106, enabling machining of the workpiece. The double fan 48 rotates simultaneously with the rotation of the rotary shaft 7. Thus, due to the rotation of the motor cooling fan 50, air flows in the motor cooling flow path R1. That is, the air sucked from the upper intake port 3c passes through the main body housing 3, the front housing 5, and the motor 6 in order to cool each of them. Then, the cooled air enters the upper space A1 of the fan housing portion 45 from the upper vent 54 and is discharged from the bottom exhaust port 70.

[0036] On one hand, due to the rotation of the dust collection fan 51, air flows in the attachment-side dust collection flow path R4 and the main unit-side dust collection flow path R2. That is, the air sucked from the suction port 106 where a suction force is generated flows in the order of the flexible hose 103, the duct 107, the dust box 93, and the exhaust pipe 116, then passes through the lower ventilation port 61 of the baffle plate 60 from the lower intake port 77 and enters the upper space A1, and is discharged from the bottom exhaust port 70. At the same time, a part of the air that has entered the upper space A1 flows into the branch flow path R3. That is, a part of the air enters the lower space A2 through the communication port 85 and is discharged from the side exhaust ports 58, 58. Therefore, the dust generated from the workpiece is sucked into the suction port 106, enters the dust box 93 through the nozzle 105, the flexible hose 103, and the duct 107, is captured by the filter 110, and is stored in the box body 111.

[0037] When removing the attachment 90, push it inward while sandwiching the finger-hooking portions 136, 136 of the hook plates 131, 131 on the left and right of the protruding portion 94. Then, the hook plates 131, 131 change from the parallel posture to the expanded posture where the upper ends expand outward to the left and right, and the claw portions 133, 133 of each other are separated from the locking grooves 56, 56. Therefore, if the attachment 90 is slid downward as it is, or the hammer drill 1 is slid upward, as shown in FIG. 16, the upper protruding strip 125 and the lower protruding strip 126 are disengaged downward from the upper engaging portion 42 and the lower engaging portion 55, respectively. At the same time, the engaging rail 123 is in the set position where it is disengaged downward from the engaging groove 43. Therefore, if the attachment 90 is relatively moved forward from the hammer drill 1, it can be separated from the hammer drill 1. Since it is only necessary to relatively move the attachment 90 from the mounting positions in FIGS. 17 and 18 to the set position in FIG. 16 in this way, the stroke of the relative movement of the attachment 90 when removing it can also be short. The dust stored in the box body 111 of the dust box 93 can be discarded by removing the dust box 93 from the attachment 90 and opening the lid 109.

[0038] (Effect of the disclosure related to the hammer drill) The hammer drill 1 of the above embodiment includes a housing 2 to which an attachment 90 can be attached, and a striking mechanism portion 20 provided in the housing 2 and capable of being struck by a striker 33 (striking element) that reciprocates a bit B (tip tool) attached to the front end. Further, the hammer drill 1 includes a motor 6 disposed in the housing 2 such that the rotation axis 7 intersects the striking axis direction of the striking mechanism portion 20, and a dust collecting fan 51 provided on the rotation axis 7. And the dust collecting fan 51 is disposed below the motor 6. According to this configuration, it is not necessary to increase the motor housing portion 35 (motor housing) in the radial direction in accordance with the outer diameter of the dust collecting fan 51. Therefore, even if the dust collecting fan 51 is provided, the compactness of the hammer drill 1 can be maintained.

[0039] In particular, a motor cooling fan 50 adjacent to the dust collecting fan 51 in the axial direction of the rotation axis 7 is provided on the rotation axis 7. Therefore, even if the motor cooling fan 50 is provided in addition to the dust collecting fan 51, it is not necessary to increase the motor housing portion 35 (accommodating portion of the motor) in the radial direction, and the compactness can be maintained. An under intake port 77 (intake port) that sucks air by the rotation of the dust collecting fan 51 is provided on the lower surface of the housing 2. Therefore, it is difficult for foreign matters such as dust to enter from the under intake port 77, and a wide opening area can be secured. A bottom exhaust port 70 (exhaust port) that discharges air by the rotation of the dust collecting fan 51 is provided on the lower surface of the housing 2. Therefore, it is difficult for foreign matters such as dust to enter from the bottom exhaust port 70, and a wide opening area can be secured. A side exhaust port 58 (second exhaust port) that discharges air by the rotation of the dust collecting fan 51 is provided on the side surface of the housing 2. Therefore, a required air volume can be secured.

[0040] The under intake port 77 can be opened and closed by a disk-shaped shutter 74. Therefore, even if the under intake port 77 is provided, the dustproofness and waterproofness of the hammer drill 1 can be ensured. The shutter 74 is arranged coaxially with the dust collecting fan 51. Therefore, the shutter 74 can be arranged compactly. Also, the air flow when the shutter 74 is opened becomes smooth. In the housing 2, the fan housing portion 45 (housing portion for the dust collecting fan) has a larger left - right width than the motor housing portion 35 in the housing 2. Therefore, the motor housing portion 35 becomes slim and looks good. The bearing 39 that supports the rotating shaft 7 in the housing 2 is arranged above the dust collecting fan 51. Therefore, the compactness of the motor housing portion 35 can be maintained including the bearing 39 portion.

[0041] The attachment 90 can be attached by sliding it relative to the housing 2 in the vertical direction (a predetermined linear direction), so that the upper engaging portion 42 and the lower engaging portion 55 provided on the housing 2 and the upper protrusion 125 and the lower protrusion 126 provided on the attachment 90 engage with each other. And the upper engaging portion 42 and the lower engaging portion 55 provided on the housing 2 are provided separately in the vertical direction. Therefore, the attachment 90 can be attached without rattling without forming the upper engaging portion 42 and the lower engaging portion 55 long. For this reason, it is not necessary to change the shape of the housing 2, and compactness and weight reduction can be maintained.

[0042] (Modification example of the disclosure related to the hammer drill) The shape and size of the dust collecting fan are not limited to the above - mentioned embodiment. For example, a dust collecting fan without a cover on the lower surface can also be adopted. Fans other than centrifugal fans can also be adopted. In the above - mentioned embodiment, a double - fan with a motor - cooling fan adjacent to the dust collecting fan is adopted, but instead of the double - fan, only a dust collecting fan may be provided below the motor. The motor only needs to be arranged such that the rotating shaft intersects the impact axis direction, and is not limited to the orthogonal arrangement as in the above - mentioned embodiment. The position and shape of the intake port are not limited to the lower intake port of the above embodiment. The shape of the shutter can also be changed as appropriate. The shutter does not have to be structured to move up and down to open and close the intake port as in the above embodiment. For example, a part of the shutter may be connected to the fan housing portion with a hinge or the like, and the shutter may be structured to rotate around an axis to open and close the intake port. The shutter may be structured to move linearly in the direction intersecting the intake port to open and close the intake port. The intake port and the exhaust port can also be provided other than on the lower surface of the housing. Therefore, the cap and the shutter may be changed in position and shape according to the position of the intake port. In the fan housing portion, the communication port between the upper space and the lower space can also be eliminated. That is, the branch flow path can be eliminated and the side exhaust port can be omitted. The form of the dust collection flow path on the main body side inside the fan housing portion can also be changed as appropriate. The air may be sent to the battery mounting portion side and used for cooling the controller.

[0043] In the present disclosure, the engaging portion with the attachment provided on the impact tool is not limited to the structure in which the upper engaging portion and the lower engaging portion in the above embodiment are separated in the vertical direction. That is, a structure in which one or a pair of convex engaging portions extending in the vertical direction and one or a pair of concave engaging portions are engaged with each other to attach the attachment may be used. In the above embodiment, the attachment is made detachable by relatively moving the attachment in the vertical direction with respect to the hammer drill, but it may be made detachable by relatively moving it in the front-rear direction or the left-right direction. However, the attachment mounting structure to the housing in the present disclosure is not limited to the engagement of the engaging portions by linear movement as in the above embodiment. For example, it can be appropriately changed to a locking and unlocking structure between a locking portion such as a hook and a locked portion such as a recess. The configuration of the impact mechanism portion is not limited to the above embodiment. Motors other than brushless motors can also be adopted. The present disclosure is applicable not only to hammer drills but also to other impact tools such as electric hammers. AC tools instead of DC tools can also be adopted.

[0044] (Effect of the disclosure related to the dust collection system) In the above-described dust collection system S, the attachment 90 can be attached by being relatively slid in the vertical direction (a predetermined linear direction) with respect to the housing 2 of the hammer drill 1, so that an upper engaging portion 42 and a lower engaging portion 55 (concave-side engaging portion) provided on the housing 2 and an upper protrusion 125 and a lower protrusion 126 (convex-side engaging portion) provided on the attachment 90 are engaged with each other. The convex-side engaging portion and the concave-side engaging portion are separated in the vertical direction, and include an upper engaging portion 42 (first concave-side engaging portion) and an upper protrusion 125 (first convex-side engaging portion) that are engaged with each other in the attached state of the attachment 90, and a lower engaging portion 55 (second concave-side engaging portion) and a lower protrusion 126 (second convex-side engaging portion) that are engaged with each other in the attached state. According to this configuration, the attachment 90 can be attached without rattling even if the upper engaging portion 42 and the lower engaging portion 55 are not formed long. Therefore, it is not necessary to change the shape of the housing 2, and compactification and weight reduction can be maintained.

[0045] In particular, a pair of the upper engaging portion 42 and the upper protrusion 125, and a pair of the lower engaging portion 55 and the lower protrusion 126 are provided on the left and right, respectively. Therefore, the attachment 90 can be attached in a well-balanced manner, and rattling of the attachment 90 in the left-right direction in the attached state can be effectively suppressed. The pair of upper engaging portion 42 and the upper protrusion 125, and the pair of lower engaging portion 55 and the lower protrusion 126 have different left-right widths from each other. Therefore, the left-right arrangement of the engaging portions according to the shape of the housing 2 is possible. The linear direction is the vertical direction, and the left-right width of the pair of upper engaging portion 42 and the upper protrusion 125 that are engaged with each other on the upper side is smaller than the left-right width of the pair of lower engaging portion 55 and the lower protrusion 126 that are engaged with each other on the lower side. Therefore, the left-right arrangement of the engaging portions according to the shapes of the upper and lower different housings 2 such as the motor housing portion 35 and the fan housing portion 45 is possible. In addition, since the left-right width of the lower engaging portions is large, the coupling state between the fan housing portion 45 and the protruding portion 94 is stabilized. The upper engaging portion 42 and the upper rib 125, and the lower engaging portion 55 and the lower rib 126 are different from each other in the front-rear direction. Therefore, the front-rear arrangement of the engaging portions according to the shape of the housing 2 becomes possible.

[0046] When attaching the attachment 90 to the housing 2 by sliding it relatively in the vertical direction, the lower engaging portion 55 and the lower rib 126 engage earlier than the upper engaging portion 42 and the upper rib 125. Therefore, the lower rib 126 is smoothly guided to the engaging position with the lower engaging portion 55 by the lower engaging portion 55 and the lower rib 126 that engage first. At a predetermined position where the attachment 90 is brought into contact with the housing 2 before sliding the attachment 90 relatively in the vertical direction, the upper engaging portion 42 and the upper rib 125, and the lower engaging portion 55 and the lower rib 126 are located on the same line in the vertical direction, respectively. Therefore, the alignment of the engaging portions can be easily performed, and the subsequent attachment of the attachment 90 can be smoothly performed. An engaging groove 43 (third concave-side engaging portion) extending in the striking axis direction of the striking mechanism portion 20 is provided in the housing 2, and an engaging rail 123 (third convex-side engaging portion) that engages with the engaging groove 43 in the state of attaching the attachment 90 to the housing 2 is provided on the attachment 90. Therefore, the rattling of the attachment 90 in the left-right direction is more effectively suppressed, and the integrality between the housing 2 and the attachment 90 is enhanced.

[0047] The attachment 90 has a protruding portion 94 located below the housing 2 in the state of being attached to the housing 2, and a hook plate 131 (hook portion) that locks to the housing 2 in the attached state is provided on the protruding portion 94. Therefore, the detachment of the attachment 90 from the housing 2 is restricted, and the attachment 90 is prevented from accidentally shifting or coming off. A dust collecting fan 51 is arranged below the motor 6, and a lower air intake port 77 for sucking air by the rotation of the dust collecting fan 51 is provided on the lower surface of the housing 2. Therefore, even if the dust collecting fan 51 is provided, it is not necessary to increase the diameter of the motor housing portion 35 in the radial direction, and the compactness can be maintained. In addition, it becomes difficult for foreign matters such as dust to enter from the lower air intake port 77, and a wide opening area can be secured.

[0048] A shutter 74 for closing the lower air intake port 77 is provided on the lower surface of the housing 2 in a state where the attachment 90 is not attached, and a pin 122 (pressing member) for moving the shutter 74 to the open position of the lower air intake port 77 in the attached state to the housing 2 is provided on the protruding portion 94. Therefore, even if the lower air intake port 77 is provided, the dustproofness and waterproofness of the hammer drill 1 can be ensured. In addition, the shutter 74 can be reliably opened by the pin 122 simultaneously with the attachment of the attachment 90. On the attachment 90, a slide portion 95 having a suction port 106 at the front end is arranged at a position offset to the left from the center in the left-right direction. Therefore, even if there is the slide portion 95, the attachment 90 can be attached to the front of the housing 2.

[0049] (Modification example of the disclosure related to the dust collection system) In the above embodiment, a groove-shaped concave engagement portion is formed on the housing side of the hammer drill, and a ridge-shaped convex engagement portion is formed on the attachment side, but the reverse may be done. That is, a ridge-shaped convex engagement portion may be formed on the housing side, and a groove-shaped concave engagement portion may be formed on the housing side. The convex engagement portion and the concave engagement portion may be provided in a mixed manner on the housing and the attachment. In the above embodiment, the lower engagement portions engage with each other earlier than the upper engagement portions, but the reverse may be done. Also, the separated engagement portions may be engaged at the same timing. The convex engagement portion and the concave engagement portion are not limited to the structure provided in pairs. For example, if the convex engagement portion and the concave engagement portion are engaged in a dovetail groove shape, they can be attached and detached even if there is one convex engagement portion and one concave engagement portion. The engaging groove and the engaging rail can be similarly modified. That is, an engaging rail may be formed on the housing side and an engaging groove may be formed on the attachment side, respectively. However, the engaging groove and the engaging rail can also be omitted. In the above embodiment, the convex engaging portion and the concave engaging portion are separated from each other at two positions in the vertical direction. They may be formed separated at three or more positions. The left - right width and the front - rear positional relationship of the convex engaging portion and the concave engaging portion can also be appropriately changed. Therefore, the left - right width and the front - rear positional relationship of the convex engaging portion and the concave engaging portion may be the same.

[0050] In the above embodiment, the attachment is made detachable by relatively moving the attachment in the vertical direction with respect to the hammer drill. However, it is also possible to make it detachable by relatively moving it in the front - rear direction or the left - right direction. Therefore, the convex engaging portion and the concave engaging portion may be oriented according to the linear direction in which the attachment is attached and detached. In the attachment, the position of the slide portion may be reversed left - right. If there is no problem with attaching the attachment, the slide portion may be arranged at the center in the left - right direction. The structure of the dust box can also be appropriately changed. The dust collection flow paths may be communicated with each other between the front surface of the housing of the percussion tool and the rear surface of the casing of the attachment without providing a protruding portion. In the above embodiment, a dust collection fan is provided in the hammer drill, and air flows in the attachment - side dust collection flow path in the attached state of the attachment. However, the present disclosure is not limited to this structure. For example, a motor and a dust collection fan may be provided in the casing of the attachment, and the motor and the dust collection fan may be rotated by obtaining power from the percussion tool in the attached state to the percussion tool. Even in such a structure, the attachment structure of the engaging portions of the present disclosure can be adopted. The configuration of the percussion mechanism portion is not limited to the above embodiment. Motors other than brushless motors can also be adopted. The direction of the motor can also be changed, and the dust collection fan may be above the motor. In the dust collection system of the present disclosure, it can be adopted not only for a hammer drill but also for other percussion tools such as an electric hammer. AC tools can also be adopted instead of DC tools.

Explanation of Reference Numerals

[0051] 1 ·· Hammer drill, 2 ·· Housing, 3 ·· Main body housing, 3c ·· Upper air inlet, 4 ·· Rear housing, 5 ·· Front housing, 6 ·· Motor, 7 ·· Rotating shaft, 16 ·· Rear cylinder part, 17 ·· Front cylinder part, 20 ·· Striking mechanism part, 21 ·· Intermediate shaft, 22 ·· Tool holder, 27, 39 ·· Bearings, 35 ·· Motor housing part, 38 ·· Bearing holding part, 42 ·· Upper engaging part, 43 ·· Engaging groove, 45 ·· Fan housing part, 46 ·· Upper plate part, 47 ·· Rear plate part, 48 ·· Double fan, 50 ·· Motor cooling fan, 51 ·· Dust collecting fan, 54 ·· Upper ventilation port, 55 ·· Lower engaging part, 58 ·· Side exhaust port, 60 ·· Baffle plate, 69 ·· Partition wall, 70 ·· Bottom exhaust port, 73 ·· Cap, 74 ·· Shutter, 75 ·· Coil spring, 77 ·· Lower air inlet, 90 ·· Dust collecting attachment, 91 ·· Casing, 92 ·· Main body part, 93 ·· Dust box, 94 ·· Protrusion, 95 ·· Slide part, 106 ·· Suction port, 110 ·· Filter, 117 ·· Exhaust port, 118 ·· Rubber cap, 122 ·· Pin, 123 ·· Engaging rail, 124 ·· Arm part, 125 ·· Upper ridge, 126 ·· Lower ridge, 131 ·· Hook plate, B ·· Bit, R1 ·· Motor cooling flow path, R2 ·· Machine side dust collecting flow path, R3 ·· Branch flow path, R4 ·· Attachment side dust collecting flow path, A1 ·· Upper space, A2 ·· Lower space, S ·· Dust collecting system.

Claims

1. A percussion tool having a housing for accommodating a motor, and a percussion mechanism provided within the housing and capable of being struck by a striker that reciprocates a tip tool attached to the front end, and a dust collection attachment attached to the housing, the dust collection system comprising: The dust collection attachment can be attached by engaging a pair of left and right convex engagement portions provided on either the housing or the dust collection attachment with a pair of left and right concave engagement portions provided on the other by sliding the dust collection attachment relative to the housing in the vertical direction. The pair of convex engagement portions and the pair of concave engagement portions are each separated into a plurality in the vertical direction, and include at least a pair of first convex engagement portions and a pair of first concave engagement portions that engage with each other on the upper side in the attached state of the dust collection attachment, and a pair of second convex engagement portions and a pair of second concave engagement portions that engage with each other on the lower side in the attached state. The left and right widths of the pair of first convex engagement portions and the pair of first concave engagement portions that engage with each other on the upper side are smaller than the left and right widths of the pair of second convex engagement portions and the pair of second concave engagement portions that engage with each other on the lower side. A dust collection system in which the pair of first convex engagement portions and the pair of first concave engagement portions on the upper side and the pair of second convex engagement portions and the pair of second concave engagement portions on the lower side are different from each other in the front-rear direction.

2. When attaching the dust collection attachment by sliding it relative to the housing in the vertical direction, either one of the pair of first convex engagement portions and the pair of first concave engagement portions on the upper side and the pair of second convex engagement portions and the pair of second concave engagement portions on the lower side engages with the other first. The dust collection system according to Claim 1.

3. At a predetermined position where the dust collection attachment is brought into contact with the housing before sliding it relative to the housing in the vertical direction, the pair of first convex engagement portions and the pair of first concave engagement portions on the upper side, and the pair of second convex engagement portions and the pair of second concave engagement portions on the lower side are each located on the same line in the vertical direction. The dust collection system according to Claim 1 or 2.

4. On either the housing or the dust collection attachment, a third convex engagement portion extending in the striking axis direction of the striking mechanism portion is provided on one side, and on the other side, a third concave engagement portion that engages with the third convex engagement portion in the attached state of the dust collection attachment to the housing is provided. The dust collection system according to any one of claims 1 to 3.

5. The dust collection attachment has a protruding portion that is located below the housing in the attached state to the housing, and a hook portion that locks to the housing in the attached state is provided on the protruding portion. The dust collection system according to any one of claims 1 to 4.

6. A dust collection fan is disposed below the motor, and an air inlet for sucking air by the rotation of the dust collection fan is provided on the lower surface of the housing. The dust collection system according to claim 5.

7. A shutter for closing the air inlet is provided on the lower surface of the housing in a state where the dust collection attachment is not attached, and a pressing member for moving the shutter to the open position of the air inlet in the attached state to the housing is provided on the protruding portion. The dust collection system according to claim 6.

8. In the dust collection attachment, a slide portion having a suction port at the front end is disposed at a position offset to either the left or right from the center in the left-right direction. The dust collection system according to any one of claims 1 to 7.

Images