JP6537402B2 - Electric tool - Google Patents

Description

  The present invention relates to a power tool using a motor as a drive source.

  In an electric power tool such as an impact driver, as shown in Patent Document 1, a motor serving as a drive source is accommodated in a motor housing, an air inlet is formed at the rear of the motor housing, and an air outlet is formed at the front. It is known that the motor can be cooled by sucking outside air from the intake port, letting the motor pass and discharging it from the exhaust port by rotation of a fan provided on the rotation shaft of the motor.

JP, 2015-33739, A

  In such an electric power tool, if water or dust infiltrates into the motor housing from an air intake port provided at the rear, etc., it contacts an electric component such as a noise filter provided in the motor housing to cause a failure, or the motor housing It might flow into the grip connected downward from the above, and there was a possibility that the electronic component such as a switch in the grip might be broken.

  Then, this invention aims at providing the electric tool which can maintain waterproofness and dust resistance with respect to an electrical-materials part, even if water and dust infiltrate from vents, such as an inlet.

In order to achieve the above object, the invention according to claim 1 supplies power to a motor, a motor housing that accommodates the motor and in which a vent is formed, a grip housing connected below the motor housing, and the motor The waterproof part which is provided in the motor housing and is inserted in the motor housing, and which cuts the wiring passage from the motor housing to the grip housing except for the insertion hole of the lead wired to the grip housing side, and the elasticity for sealing the insertion hole body and, Ri Na comprise, motor is a commutator motor having a commutator, waterproof portion, projecting from the inner surface of the motor housing below the vent, the brush holder for holding the sliding contact brush commutator in a waterproof rib abuts block the wire passage, characterized in that the insertion hole is formed between the waterproof rib formed notched portion at an end portion and the brush holder To.
To achieve the above object, the invention according to claim 2, a commutator motor having a commutator, and a brush holder for holding the sliding contact brush commutator, houses a commutator motor, the rear opening Electric power is supplied to the motor housing consisting of a cylindrical part on which the brush holder is held , a back cover formed with a vent and a rear cover screwed to the cylindrical part from behind , a grip housing connected below the motor housing, and electric power The lead wire for supplying and the insertion hole of the lead wire which is provided on the rear cover and divides the rear space of the brush holder up and down below the air vent in the state of screwing to the cylindrical part and wired to the grip housing side And a waterproof portion for closing the wiring passage from the motor housing to the grip housing, and an elastic body for sealing the insertion hole.

  According to the present invention, even if water or the like infiltrates from the vent, the movement of water or the like to the electrical component such as the switch or the noise filter can be suppressed by the waterproof portion or the waterproof rib. Therefore, waterproofness and dustproofness to the electric material parts can be maintained.

It is a longitudinal cross-sectional view of an impact driver. It is an enlarged view of a main-body part. It is a perspective view from the back of a body part which removed a back cover. FIG. 3 is a partial cross-sectional view taken along line AA of FIG. It is an enlarged view of the main-body part which has a waterproof structure of a modification. It is the BB sectional drawing of FIG. It is a side view of the right half housing. It is a perspective view of the left and right half housings.

Hereinafter, embodiments of the present invention will be described based on the drawings.
FIG. 1 is a longitudinal sectional view of an impact driver which is an example of a power tool. The impact driver 1 has a main body 2 having a central axis in the front-rear direction, and a grip 3 as a grip housing protruding downward from the main body 2. A battery mounting portion 4 provided at the lower end of the grip 3 The battery pack 5 serving as a power source is attached to the A switch 6 in which the trigger 7 is protruded forward is accommodated in the upper part of the grip portion 3, and a terminal block 8 electrically connected to the battery pack 5 and a microcomputer are mounted in the battery mounting portion 4. A control circuit board 9 is provided internally. A switch panel 10 having a push button for changing the rotational speed and a display unit for the remaining capacity of the battery is provided on the front upper surface of the battery mounting unit 4.

  FIG. 2 is an enlarged cross-sectional view of the main body 2, in which the motor 11, the planetary gear reduction mechanism 12, the spindle 13, the striking mechanism 14, and the anvil 15 are accommodated in the main body 2 from the rear, It projects forward from the front end of the main body 2. At the rear of the main body 2, there is a motor housing 16 comprising a cylindrical portion 17 accommodating the motor 11 and integrated with the grip portion 3 and a rear cover 18 as a rear housing for closing the rear end of the cylindrical portion 17 It is provided. The cylindrical portion 17 and the grip portion 3 are formed of a pair of left and right half housings HR and HL made of resin in which the cylindrical portion 17 and the grip portion 3 are integrally formed by a plurality of screws 19, 19. It is assembled and formed.

  In the grip portion 3, between the switch 6 and the control circuit board 9, inverted L-shaped waterproof ribs 20 and 20 (FIG. 8) are provided to divide the inside of the grip portion 3 vertically by the half housings HR and HL. The rubber seal material 21 having the same shape is interposed between the left and right waterproof ribs 20, which are provided. The rubber seal material 21 has a rectangular tube portion 22 through which a lead wire (not shown) for connecting the switch 6 and the control circuit board 9 penetrates, and water or the like which has entered the grip portion 3 from the opening for projecting the trigger 7 A dust is prevented from moving to the control circuit board 9 side, and a through hole 23 for discharging water or the like blocked by the rubber sealing material 21 is formed on the rear surface of the grip portion 3 behind the rubber sealing material 21. .

  The rear portion of the cylindrical portion 17 is cut out in an L shape in side view, and as shown in FIG. 3, a circular rear opening 24 which opens perpendicularly to the axis of the cylindrical portion 17, and a rear opening A downward U-shaped lower opening 25 is formed continuously from the bottom of the portion 24 to the rear. The rear cover 18 includes a circular back portion 26 and a side portion 27 connected forward to the outer periphery of the back portion 26. The lower portion of the back portion 26 and the side portion 27 has a shape of the lower opening 25. A U-shaped notch 28 is formed. A ridge 29 is formed on the periphery of the rear opening 24 and the lower opening 25 of the cylindrical portion 17 toward the inner periphery, and the inner periphery of the side surface 27 of the rear cover 18 and the notch 28 is convex The rear cover 18 is connected to the cylindrical portion 17 by means of a recess 30 in which the bar 29 is fitted. Inside the ridges 29 of the rear opening 24, a pair of projecting pieces 31, 31 project inward, and screwing bosses 32 are provided on the projecting pieces 31 so as to project rearward. The rear cover 18 is engaged with the rear end of the cylindrical portion 17, and the cylindrical portion 17 is screwed into the screwing bosses 32 and 32 with screws (not shown) penetrating from the rear to the rear portion 26. Attached to

The motor 11 is a commutator motor including a cylindrical stator 33 and a rotor 34 coaxially penetrating the stator 33. The stator 33 is formed in the circumferential direction on the inner surface of the cylindrical portion 17. Retained by ribs 35,35. Reference numeral 36 denotes a holding rib for holding the lower side of the stator 33 in the cylindrical portion 17. The receiving rib 35 is formed over the upper surface of the holding rib 36.
The rotor 34 includes a rotating shaft 37 located at the axial center, a commutator 38 provided at the rear end of the rotating shaft 37, and a centrifugal fan 39 provided at the front of the commutator 38. Are supported by bearings 40 held by the rear cover 18. The front end of the rotary shaft 37 protrudes forward through the bearing retainer 41 held by the cylindrical portion 17, is supported by the bearing 42 held by the bearing retainer 41, and the pinion 43 is fitted at the tip Ru. A plurality of exhaust ports 44 are formed outside the centrifugal fan 39 on the left and right side surfaces of the cylindrical portion 17, and a plurality of front intake ports 45 are formed in front of the exhaust ports 44. A noise filter 46 is provided below the holding rib 36 in the cylindrical portion 17.

  Reference numeral 47 denotes a brush holder provided at the rear opening 24 of the cylindrical portion 17. The brush holder 47 includes a cylindrical portion 48 through which the commutator 38 passes at the center, and as shown in FIG. 4, the brush holder 47 is engaged with a groove 49 formed on the inner periphery of the ridge 29 of the rear opening 24 and held. On the left and right, relief portions 50, 50 through which screw bosses 32, 32 pass are formed. Here, an extension piece 51 is formed at the rear end of the left ridge 29 so as to protrude to the center side and overlap on the rear surface of the brush holder 47. A pair of metal sleeves 52, 52 respectively holding the carbon brush 53 are disposed in a V-shape in rear view on the rear surface of the brush holder 47 and above the cylindrical portion 48. Reference numeral 54 denotes a torsion spring which biases the carbon brush 53 to the commutator 38 side. The lead wires 55, 55 connected to the left and right sleeves 52, 52 are drawn downward from the both sides of the cylindrical portion 48 by the rear surface of the brush holder 47, and project downward from the cylindrical portion 48 at the center in the horizontal direction. It is held between the central projection 56 and a pair of guide projections 57, 57 projecting on both sides thereof. Thereafter, each lead 55 is drawn into the cylindrical portion 17 from the lower opening 25 and penetrates the noise filter 46.

  Further, a holding portion 58 of the bearing 40 of the rotary shaft 37 is formed inside the rear surface portion 26 of the rear cover 18, and the sleeves 52 and 52 are in contact with the upper side of the holding portion 58 in the assembled state of the rear cover 18. Retaining recesses 60, 60 for retaining the rubber pins 59, 59 in contact are formed. Reference numeral 61 denotes a receiving portion through which a screw is passed and the screwing boss 32 is fitted. Further, in the back face portion 26, a plurality of rear air inlets 62, 62,... As air vents are radially formed.

  Furthermore, a waterproof rib 63 is formed on the inner side of the rear cover 18 so as to extend across the back surface portion 26 and the side surface portion 27 and which divides the notch 28 and the rear air inlet 62 from each other. . The waterproof rib 63 abuts on the rear surface of the brush holder 47 between the cylindrical portion 48 and the central projection 56 and the guide projection 57 in the assembled state of the rear cover 18 and divides the rear space of the brush holder 47 up and down. At the center of the front end of the waterproof rib 63, as shown in FIG. 4, the lead 55 has a width and a depth which do not overlap with the central projection 56 and the guide projections 57 and 57 in plan view. A notch 64 is formed to form the 55 insertion holes. In the cutout portion 64, a plate-shaped sponge 65 (shaded portion) as an elastic body of a single bubble (closed cell) is provided, and compressed between the brush holder 47 and the lead wires 55, 55 There is. Therefore, the rear space of the brush holder 47 serving as the wiring passage to the grip portion 3 is sealed by the waterproof rib 63 and the sponge 65.

On the other hand, the bearing retainer 41 is a disc made of metal having a constricted portion 66 formed at the center, and the retaining retainer 67 provided on the inner surface of the cylindrical portion 17 engages with the constricted portion 66. It is hold | maintained in the cylindrical part 17 in the state by which the movement to the front-back direction was controlled.
Further, a ring wall 68 having a male screw formed on the outer periphery thereof is protruded forward on the front peripheral edge of the bearing retainer 41, and the spindle 13, the striking mechanism 14, and the anvil 15 are accommodated in the ring wall 68. The hammer case 69 is screwed in.

The hammer case 69 is a metal cylindrical body in which the front half portion is tapered to form the front cylinder portion 70, and the bearing retainer 41 serves as a lid to close the rear portion. A locking projection 71 is formed on the lower surface of the hammer case 69, and in the assembled state, the pressing ribs 72 and 72 (FIGS. 7 and 8) protrudingly provided on the inner surfaces of the left and right half housings HR and HL respectively It comes in contact with the side surface of 71. Further, also on the left and right of the hammer case 69, the not-shown convex portion on the hammer case 69 side and the concave portion 73 (FIGS. 7 and 8) on the half housings HR and HL side are fitted. The rotation of the hammer case 69 is restricted by the engagement between the locking projection 71 and the pressing rib 72 and the projection and the recess 73.
Between the hammer case 69 and the switch 6, the forward / reverse switching lever 74 of the motor 11 is slidably provided to the left and right, and an LED 75 for illuminating the front of the anvil 15 is attached obliquely upward in front of it. .
Further, a resin cover 76 is provided in front of the cylindrical portion 17 to cover the front cylinder portion 70 from the front of the hammer case 69, and a rubber bumper 77 is attached to the outer periphery of the front end of the cover 76. ing.

At the front of the bearing retainer 41, the rear end of the spindle 13 is supported via a bearing 78. The spindle 13 has a hollow, disk-like carrier portion 79 at the rear, and the pinion 43 of the rotating shaft 37 is projected from the rear surface into the bottomed hole 80 formed in the axial center.
The planetary gear reduction mechanism 12 includes an internal gear 81 having internal teeth, and three planetary gears 82, 82,... Having external teeth meshing with the internal gear 81. The internal gear 81 is coaxially accommodated inside the ring wall 68 of the bearing retainer 41, and the thick portion 83 provided on the front outer peripheral side is engaged with the inner peripheral surface of the hammer case 69 and prevented from rotating. At the same time, it is held between the ring wall 68 and the step portion 84 provided on the inner periphery of the hammer case 69 to restrict axial movement.

An O-ring 85 is interposed between the rear end of the internal gear 81 and the front surface of the bearing retainer 41. The O-ring 85 seals the gap between the internal gear 81 and the bearing retainer 41, and The impact on the bearing retainer 41 from the null gear 81 is also alleviated.
The planetary gears 82 are rotatably supported by the pins 86 in the carrier portion 79 of the spindle 13 and mesh with the pinions 43 of the rotating shaft 37.

  The striking mechanism 14 includes a hammer 87 mounted on the spindle 13 and a coil spring 88 for biasing the hammer 87 forward. First, the hammer 87 has a pair of claws (not shown) on the front surface, and is engaged with the outer cam grooves 89 and 89 formed on the inner surface and the inner cam grooves 90 and 90 formed on the surface of the spindle 13 It is connected to the spindle 13 via the balls 91, 91 to be combined. In addition, a ring-shaped groove 92 is formed on the rear surface of the hammer 87, and the front end of the coil spring 88 is inserted therein. The rear end of the coil spring 88 is in contact with a spring receiver 93 provided on the front surface of the carrier portion 79. At the bottom of the groove 92, a plurality of balls 94, 94... And a washer 95 are accommodated so as to receive the front end of the coil spring 88.

The anvil 15 is pivotally supported by a bearing 96 held by the front cylindrical portion 70 of the hammer case 69, and at the rear end, a pair of arms 97, 97 engaging in rotation with the claws of the hammer 87 are formed. There is. At the front of the arm 97, on the rear surface of the bearing 96, a ring-shaped protrusion 98 is provided, and on the outside of the protrusion 98, a resin washer 99 for receiving the arm 97 is fitted.
Further, a fitting hole 100 is formed in the rear surface axial center of the anvil 15, and the front end of the spindle 13 is coaxially inserted into this. Reference numeral 101 denotes a supply path for supplying grease by connecting the fitting hole 100 and the inner surface of the bearing 96 in the radial direction.
On the other hand, an insertion hole 102 for receiving a bit (not shown) is formed in the front axial center of the anvil 15, and the front end of the anvil 15 comprises a ball 103 and a sleeve 104 etc. for retaining the bit inserted into the insertion hole 102. A chuck mechanism is provided.

  In the impact driver 1 configured as described above, when the trigger 7 is pushed in and the switch 6 is turned on, the motor 11 is supplied with power and the rotating shaft 37 rotates. Then, the planetary gear 82 meshing with the pinion 43 revolves within the internal gear 81, and decelerates and rotates the spindle 13 via the carrier portion 79. Therefore, the hammer 87 is also rotated to rotate the anvil 15 via the arms 97, 97 engaged with the claws, and enables screwing with a bit. As screw tightening progresses and the torque of the anvil 15 increases, the hammer 87 retracts against the bias of the coil spring 88 while rolling the balls 91, 91 along the inner cam grooves 90, 90 of the spindle 13, When the claws move away from the arms 97, 97, the biasing force of the coil spring 88 and the guiding of the inner cam groove 90 cause the hammer 87 to rotate while advancing to engage the claws again to the arms 97, 97 and rotate the anvil 15. Generate impact force (impact). This repetition enables further tightening.

Then, when the centrifugal fan 39 rotates with the rotation of the rotary shaft 37, the air sucked from the front intake port 45 passes through the motor 11 to cool the motor 11, and then is discharged from the exhaust port 44 and After the air drawn in from the air inlet 62 passes through the cylindrical portion 48 of the brush holder 47 to cool the commutator 38, the air is discharged from the air outlet 44.
Here, even if water or dust may intrude into the motor housing 16 from the rear air inlet 62, the lower side of the rear cover 18 is closed by the waterproof rib 63 and the sponge 65 with the brush holder 47. Therefore, water and dust are blocked by the waterproof rib 63 and the sponge 65, and are not infiltrated to the grip 3 side.

  As described above, according to the impact driver 1 of the above embodiment, the grip portion is removed from the motor housing 16 except for the insertion hole (notch portion 64) of the lead wire 55 provided in the motor housing 16 and wired to the grip portion 3 side. By providing the waterproof rib 63 for closing the wiring passage to 3 and the elastic body (sponge 65) for sealing the insertion hole, even if water or the like enters from the rear air inlet 62, the waterproof rib 63 and the sponge 65 It is possible to suppress the movement of water or the like to the electronic component such as the switch 6 or the noise filter 46. Therefore, waterproofness and dustproofness to the electric material parts can be maintained.

  In the above embodiment, the rear cover is provided with a waterproof rib to prevent water or the like from entering the grip portion, but the structure of the waterproof portion is not limited to this. For example, FIGS. 5 to 8 show a modified example of the waterproof portion, and in the impact driver 1A, the waterproof portion is provided in the cylindrical portion 17. First, in the left half housing HL, on the lower rear side of the holding rib 36, a concave rib 105 in which a slit 106 through which the lead wires 55 pass in the back and forth is formed in the bottom portion It is formed by closing clothes. On the other hand, in the right half housing HR, on the lower rear side of the holding rib 36, there is formed a convex rib 107 which is fitted to the concave rib 105 in the assembled state to close the slit 106 from the side. And the penetration part of the lead wire 55,55 is sealed by stuffing the sponge 65 in a compressed state in the slit 106 used as a penetration hole, and making it clamp.

Also in this modification, even if water or dust may intrude into the motor housing 16 from the rear intake port 62, the waterproof portion (concave rib 105 and the rear portion between the noise filter 46 and the rear intake port 62) Since it is closed by the convex rib 107 and the sponge 65, water and dust are blocked by both the ribs 105 and 107 and the sponge 65, and they do not infiltrate the grip 3 side. Therefore, waterproofness and dustproofness with respect to the electric material parts such as the switch 6 and the noise filter 46 can be maintained.
However, the concave rib and the convex rib may be provided in opposite directions, and the slit may be provided on the convex rib side or may be provided straddling both ribs.

On the other hand, in the above embodiment and modifications, the elastic body is not limited to a single foam sponge, and rubber or the like may be adopted, or elastic bodies different in material or characteristics may be used repeatedly.
The motor housing may also be assembled with a half housing integrated with a rear cover. In this case, it is conceivable that the waterproof ribs are separately provided in the left and right half housings, and in the assembled state, the lead wires are inserted through the butt portions of the waterproof ribs and sealed by the elastic body. The elastic body may also be divided into right and left, and be affixed to the butted portion of the left and right waterproof ribs in advance.
Furthermore, even if the motor is not limited to the commutator motor, even if it is a brushless motor etc., it is possible to similarly seal the wiring passage of the lead wire by adopting the waterproof part.

  1, 1 A · · · Impact driver, 2 · · body portion, 3 · · grip portion, 5 · · · battery pack, 9 · · control circuit board, 11 · motor, 12 · planetary gear reduction mechanism, 13 · · spindle · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · , 27 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · centrifugal fan, 44 · · · exhaust port, 45 · · · Front intake port, 46 · · Noise filter, 47 · · Brush holder, 55 · · Lead wire, 56 · · Central projection, 57 · · Guide projection, 62 · · Rear intake port, 63 · · · Waterproof rib, 64 · · · Notched part, 65 · · sponge, 69 · · hammer case, 87 Hammer, 88 ... coil spring, 105 ... recessed ribs, 106 ... slits, 107 ... convex ribs, HR ... right half housing, HL ... left half housings.

Claims (2)

Motor,
A motor housing that accommodates the motor and in which a vent is formed;
A grip housing connected below the motor housing;
Lead wires for supplying power to the motor;
A waterproof portion which is provided in the motor housing and blocks a wiring passage from the motor housing to the grip housing except for an insertion hole of the lead wire wired to the grip housing side;
Ri Na comprise an elastic member for sealing the insertion hole,
The motor is a commutator motor having a commutator, and the waterproof portion is provided on the inner surface of the motor housing below the air vent and is in contact with a brush holder that holds a brush in sliding contact with the commutator. It is a waterproof rib which closes the said wiring passage, Comprising: The said insertion hole is formed between the notch part formed in the edge part of the said waterproof rib, and the said brush holder . A commutator motor having a commutator ,
A brush holder for holding a brush in sliding contact with the commutator;
A motor housing comprising: a cylindrical portion accommodating the commutator motor and holding the brush holder at the rear opening; and a rear cover formed with a vent and screwed from the rear to the cylindrical portion .
A grip housing connected below the motor housing;
Leads for supplying power to the brushes ;
The rear space is provided on the rear cover, and the rear space of the brush holder is vertically partitioned below the air vent in a screwed state to the cylindrical portion, excluding the lead holes of the lead wires wired to the grip housing side A waterproof portion for closing a wiring passage from the motor housing to the grip housing;
And an elastic body sealing the insertion hole.

Images