JP6394330B2 - Electric working machine - Google Patents

Description

  The present invention relates to an electric working machine capable of switching a rotor of an electric motor between rotation and stop.

  Conventionally, a drill as an electric working machine can switch the rotation direction of a rotor that transmits torque to a work tool. Such an electric working machine is described in Patent Document 1. The electric working machine described in Patent Literature 1 includes a housing and an electric motor provided in the housing. The electric motor includes a stator and a rotor, and the stator has a coil through which a current flows, and the rotor is provided with a commutator. The stator is attached to the housing, and a switching member is provided on the outer peripheral surface of the stator. The switching member has a cylindrical shape, and the switching member can be rotated around the axis of the rotor with respect to the stator.

  The switching member is provided with a contact connected to the coil. The switching member holds a brush, and the brush contacts the commutator. In the electric working machine described in Patent Document 1, the operator rotates the switching member with respect to the housing to switch the direction of the current flowing in the coil and the connection or disconnection of the electric circuit connected to the coil. As a result, the stop and rotation of the rotor are switched, and the forward rotation and the reverse rotation when the rotor rotates are switched.

JP-A 62-16052

  The electric working machine described in Patent Document 1 has a problem that when the rotor is rotated, the switching member moves in the radial direction around the axis with respect to the housing.

  An object of the present invention is to provide an electric working machine capable of suppressing a switching member from moving in a radial direction centering on an axis with respect to a housing when rotating a rotor.

An electric working machine according to an embodiment is an electric working machine capable of switching between rotation and stop of a rotor of an electric motor, the trigger being operated by an operator to switch between rotation and stop of the rotor, and the rotor A housing that is housed, a first position that is rotatably attached to the housing about the axis of the rotor and that does not rotate the rotor even when the trigger is operated, and the rotor rotates when the trigger is operated A switching member that can be switched to a second position, and the switching member includes a first guide portion that is arranged in a circumferential direction around the axis, and the housing is circumferential around the axis A second guide portion that is disposed in a direction and positions the switching member in a radial direction around the axis in cooperation with the first guide portion; Parts, the is axis disposed more inside than the first guide portion in the radial direction about the, in the radial direction around the axis, and the outer surface of the inner surface and the second guide portion of said first guide portion A gap is formed between the switch member and the gap amount when the switch member is at the second position is smaller than the gap amount when the switch member is at the first position.

  An electric working machine according to another embodiment includes a housing that supports the rotor, a switching member that is rotatable with respect to the housing about the axis of the rotor, and that switches between rotation and stop of the rotor; A first guide portion arranged in the circumferential direction around the axis line on the switching member, and a circumferential direction arranged in the circumferential direction around the axis line in the housing, and arranged inside the first guide portion. The second guide portion, the first flat surface and the first circular arc surface provided on the inner surface of the first guide portion and arranged along the circumferential direction centering on the axis, and the second A second flat surface and a second arc surface provided on an outer surface of the guide portion and disposed along a circumferential direction centered on the axis, and the second arc surface centered on the axis The first radius and the axis The magnitude of the second radius of the first arc surface as the center, the shortest first distance from the axis to the second flat surface, and the shortest second distance from the axis to the first flat surface The relationship is second distance ≦ first radius <second radius, and first distance <second distance.

  According to the present invention, it is possible to suppress the switching member from moving in the radial direction with respect to the housing.

It is front sectional drawing which shows embodiment of the electric working machine of this invention. It is a front view of the electric working machine of this invention. It is a schematic diagram which shows the electric circuit in the electric working machine of this invention. It is a disassembled perspective view of the components used for the electric working machine of this invention. It is a disassembled perspective view of the components used for the electric working machine of this invention. It is the perspective view which assembled the components used for the electric working machine of this invention. In the electric working machine of the present invention, it is a left side view with the handle removed. In the electric working machine of the present invention, it is a left side view with the handle removed. In the electric working machine of the present invention, it is a left side view with the handle removed. In the electric working machine of the present invention, it is a right side view showing the positional relationship between the casing and the brush support. In the electric working machine of the present invention, it is a right side view showing the positional relationship between the casing and the brush support. In the electric working machine of the present invention, it is a right side view showing the positional relationship between the casing and the brush support. In the electric working machine of the present invention, it is a left side view in which the brush support is stopped at the first operation position. In the electric working machine of the present invention, it is a left side view in which the brush support is stopped at the second operation position. In the electric working machine of the present invention, it is a left side view in which the brush support is stopped at the third operation position.

  Hereinafter, an embodiment of an electric working machine of the present invention will be described in detail with reference to the drawings.

  The electric working machine 10 according to the present embodiment is a drill capable of forming a hole, a groove, or the like in an object. The electric working machine 10 includes a handle 11 that an operator holds by hand, a housing 12 fixed to the handle 11, an inner cover 13 fixed to the housing 12, and a gear cover 14 fixed to the inner cover 13. ing. The handle 11 is made of synthetic resin, the housing 12 is made of metal, and the metal used for the housing 12 includes, for example, aluminum and magnesium. The inner cover 13 is made of synthetic resin or metal. The gear cover 14 is made of synthetic resin or metal.

  A power cable 15 is attached to the handle 11, and a plug 16 provided at an end of the power cable 15 is connected to an AC power supply 90. An electric motor 17 is provided across the interior of the housing 12 and the inner cover 13. The electric motor 17 is an AC motor, and the electric motor 17 includes a stator 18 and a rotor 19. A reduction mechanism is provided inside the inner cover 13 and the gear cover 14, and the torque of the rotor 19 is transmitted to the input member of the reduction mechanism. A chuck 20 is provided outside the gear cover 14, and torque of the output member of the speed reduction mechanism is transmitted to the chuck 20. That is, the chuck 20 is connected to the rotor 19 so that power can be transmitted. The chuck 20 holds a drill bit as a work tool.

  The axis A1 that is the rotation center of the rotor 19 and the axis B1 that is the rotation center of the chuck 20 are parallel to each other. That is, in the electric working machine 10, the rotor 19 and the chuck 20 are arranged so as to be eccentric from each other. The housing 12 is disposed between the inner cover 13 and the handle 11 in the direction along the axis A <b> 1, and the inner cover 13 is disposed between the gear cover 14 and the housing 12. A screw member 21 that fixes the housing 12, the inner cover 13, and the gear cover 14 to each other is provided. Further, a screw member 22A for fixing the housing 12 and the handle 11 to each other is provided.

  The stator 18 is fixed in a cylindrical stator holder 24. Stator 18 has an iron core and coils 23A and 23B wound around the iron core. The stator 18 is an element that functions as a field. The stator holder 24 is integrally formed of an insulating material such as synthetic resin. The stator holder 24 is disposed and fixed in the housing 12. Further, an insulator 25A that covers the coil 23A is provided, and an insulator 25B that covers the coil 23B is provided. Paper can be used as the insulators 25A and 25B. A pair of projecting portions 26 extending in the direction along the axis A1 are provided from the end of the stator holder 24 in the direction along the axis A1, and a connecting portion 35 for connecting the pair of projecting portions 26 is provided. It has been. A shaft hole 27 is provided in the connecting portion 35. Further, a boss portion 42 having a shaft hole 41 is provided on the outer peripheral surface of the stator holder 24. The screw member 22B is inserted into the shaft hole 41 and tightened, and the handle 11 and the stator holder 24 are fixed.

  On the other hand, the rotor 19 has an output shaft 28 and an armature 29 attached to the output shaft 28. The armature 29 is obtained by winding a coil around an iron core. Further, a commutator 30 that is attached to the output shaft 28 and supplies current to the armature 29 is provided. The commutator 30 is disposed outside the stator holder 24 and is disposed between the overhang portions 26.

  The housing 12 includes a cylindrical portion 31, a pair of guide rails 32A and 32B extending from the cylindrical portion 31 in the direction along the axis A1, and a holding portion 33 that connects the guide rails 32A and 32B. . The guide rails 32A and 32B are arranged outside the pair of projecting portions 26 in the radial direction centering on the axis A1. The guide rails 32A and 32B are each provided in an arc shape within a predetermined angle range that is point-symmetric in the circumferential direction about the axis A1.

  The guide rail 32A and the guide rail 32B are provided in opposite ranges in the circumferential direction around the axis A1. The holding portion 33 has a cylindrical shape, and a bearing 34 is provided in the holding portion 33. The bearing 34 rotatably supports the output shaft 28. A part of the output shaft 28 is disposed in the shaft hole 27. The overhang portion 26, the guide rails 32 </ b> A and 32 </ b> B, and the bearing 34 are arranged in the handle 11.

  Notch portions 36A and 36B are provided at the ends where the guide rails 32A and 32B are provided in the direction along the axis A1 of the cylindrical portion 31. The notches 36A and 36B are provided in an arc shape within a predetermined angle range centered on the axis A1. The notches 36A and 36B are arranged in a range different from the range in which the guide rails 32A and 32B are arranged in the circumferential direction around the axis A1. Further, a restricting portion 38 is provided at an end portion where the guide rails 32A and 32B are provided in a direction along the axis A1 of the cylindrical portion 31. The restricting portion 38 is disposed at two places different from the notches 36A and 36B in the circumferential direction of the cylindrical portion 31 with the axis A1 as the center. The range in which the two restricting portions 38 are arranged in the circumferential direction of the cylindrical portion 31 centering on the axis A1 is the same as the range in which the guide rails 32A and 32B are provided.

  Two arcuate surfaces 100A and 100B and a flat surface 100C are provided on the outer surface of the guide rail 32A. On the outer surface of the guide rail 32A, two arcuate surfaces 100A, 100B and a flat surface 100C are provided in a direction along the axis A1 at a position closer to the restricting portion 38 than an intermediate position between the holding portion 33 and the restricting portion 38. It has been. The two arcuate surfaces 100A and 100B and the flat surface 100C have a predetermined width in the direction of the axis A1. Further, the flat surface 100C is disposed between the circular arc surface 100A and the circular arc surface 100B in the circumferential direction about the axis A1. In a plan view perpendicular to the axis A1, the arc surfaces 100A and 100B are set to a radius L1 with a curvature centered on the axis A1. Further, the shortest distance L2 is set between the axis A1 and the flat surface 100C. The distance L2 is the length of a straight line extending from the axis A1 to the flat surface 100C and perpendicular to the flat surface 100C.

  Two arcuate surfaces 101A and 101B and a flat surface 101C are provided on the outer surface of the guide rail 32B. On the outer surface of the guide rail 32B, two arcuate surfaces 101A and 101B and a flat surface 101C are provided in a direction along the axis A1 at a position closer to the restricting portion 38 than an intermediate position between the holding portion 33 and the restricting portion 38. It has been. The two arcuate surfaces 101A and 101B and the flat surface 101C have a predetermined width in the direction of the axis A1. Further, the flat surface 101C is disposed between the circular arc surface 101A and the circular arc surface 101B in the circumferential direction centering on the axis A1. In a plan view perpendicular to the axis A1, the circular arc surfaces 101A and 101B are set to a radius L1 with a curvature centered on the axis A1. Further, the shortest distance L2 is set between the axis A1 and the flat surface 101C. The distance L2 is the length of a straight line extending from the axis A1 to the flat surface 101C and perpendicular to the flat surface 101C.

  Further, a boss portion 40 having a shaft hole 39 is provided on the outer peripheral surface of the cylindrical portion 31. The screw member 22A is inserted into the shaft hole 39 and tightened. Further, the boss portion 42 is disposed in the notch portion 36B.

  A trigger 62 is provided on the handle 11. The trigger 62 is operated by an operator. A protrusion 87 is provided on the trigger 62, and the protrusion 87 has a stopper 88. A brush support 43 is attached to the outer surfaces of the guide rails 32A and 32B. The brush support 43 is made of an insulating material, for example, a synthetic resin. The brush support 43 is annular, and the brush support 43 includes a pair of arc portions 44A and 44B, a first plate portion 45 connecting the first ends of the pair of arc portions 44A and 44B, and a pair of arc portions 44A. , 44B, and a second plate portion 46 that connects the second end portions of each other. The first plate part 45 and the second plate part 46 are arranged at different positions in the circumferential direction of the brush support 43.

  The guide rails 32A and 32B are located inside the pair of arc portions 44A and 44B in the radial direction centered on the axis A1. In the circumferential direction around the axis A1, the first plate portion 45 is disposed at a location corresponding to the notch portion 36A, and the second plate portion 46 is disposed at a location corresponding to the notch portion 36B. . Knob portions 47 are provided so as to project outward from the outer peripheral surfaces of the pair of arc portions 44A and 44B.

  The arc portions 44 </ b> A and 44 </ b> B cooperate with the guide rails 32 </ b> A and 32 </ b> B to position the brush support 43 in the radial direction with respect to the housing 12. Three flat surfaces 102A, 102B, and 102C are provided on the inner surface of the arc portion 44A at different positions in the circumferential direction. Further, on the inner surface of the arc portion 44A, an arc surface 103A is provided between the flat surface 102A and the flat surface 102B, and an arc surface 103B is provided between the flat surface 102B and the flat surface 102C. Further, the shortest distances L3 are set from the axis A1 to the flat surfaces 102A, 102B, and 102C. The distance L3 is the length of a straight line that extends from the axis A1 to each of the flat surfaces 102A, 102B, and 102C and is perpendicular to each of the flat surfaces 102A, 102B, and 102C. The circular arc surfaces 103A and 103B are set to a radius L4 with a curvature centered on the axis A1.

  Three flat surfaces 104A, 104B, and 104C are provided on the inner surface of the arc portion 44B at different positions in the circumferential direction. Further, an arc surface 105A is provided between the flat surfaces 104A and 104B on the inner surface of the arc portion 44B, and an arc surface 105B is provided between the flat surfaces 104B and 104C. Further, the shortest distances L3 are set from the axis A1 to the flat surfaces 104A, 104B, and 104C. The distance L3 is a length of a straight line extending from the axis A1 to each of the flat surfaces 104A, 104B, and 104C and perpendicular to each of the flat surfaces 104A, 104B, and 104C. The circular arc surfaces 105A and 105B are set to a radius L4 with a curvature centered on the axis A1.

The magnitude relationship between the radii L1 and L4 and the distances L2 and L3 is as follows.
Distance L3 ≦ radius L1 <radius L4
And,
Distance L2 <Distance L3
It is.

  With the brush support 43 attached to the outer surfaces of the guide rails 32A and 32B, the arc surfaces 100A, 100B, 101A, and 101B and the flat surfaces 100C and 101C are arranged in the direction along the axis A1. 102A, 102B, 102C, arcuate surfaces 103A, 103B, flat surfaces 104A, 104B, 104C, and arcuate surfaces 105A, 105B overlap at least partially.

  A brush 51 is attached to the first plate portion 45 of the brush support 43 via a brush holder 50, and a brush 53 is attached to the second plate portion 46 via a brush holder 52. The brush support 43 supports two brushes 51 and 53. The brushes 51 and 53 are both made of carbon, and are provided inside the brush support 43 in the radial direction with the axis A1 as the center. The two brushes 51 and 53 are arranged at an interval of 180 degrees in the circumferential direction around the axis A1. The brushes 51 and 53 are for energizing the commutator 30. The brushes 51 and 53 are pushed inward in the radial direction by the elastic body 84, and the brushes 51 and 53 are in contact with the commutator 30.

  Two slits 54 and 55 are provided on the outer periphery of the second plate portion 46. The slits 54 and 55 are arranged at intervals in the circumferential direction around the axis A1. The second plate portion 46 includes a block portion 56 disposed between the slit 54 and the slit 55 in the circumferential direction centering on the axis A1. The arrangement positions of the slits 54 and 55 and the block portion 56 partially overlap with the arrangement position of the stopper 88 in the radial direction centering on the axis A1. In the radial direction centered on the axis A <b> 1, the arrangement range of the protrusions 87 includes the arrangement positions of the slits 54 and 55 and the block part 56, and includes the outside of the arrangement positions of the slits 54 and 55 and the block part 56. . Further, the second plate portion 46 includes convex portions 57 and 58. The slits 54 and 55 and the block portion 56 are arranged between the convex portion 57 and the convex portion 58 in the circumferential direction centering on the axis A1.

  Further, a support member 59 is provided on the inner side of the brush support 43 and on the outer side of the guide rail 32 in the radial direction centered on the axis A <b> 1. The support member 59 is formed of an insulating material, for example, a synthetic resin. The support member 59 includes a cover 60 that covers the brush holder 50 and a cover 61 that covers the brush holder 52. The support member 59 is annular, and the brush support 43 and the support member 59 are positioned and fixed in the circumferential direction about the axis A1. And the support member 59 and the brush support 43 can operate | move to the circumference direction centering on axis line A1, in the state which the inner surface of the brush support 43 contacted the outer surface of the guide rail 32. FIG.

  An opening 49 is provided between the edge of the housing 12 and the edge 48 of the handle 11. The openings 49 are arranged at two locations at intervals of 180 degrees in the circumferential direction centered on the axis A1. Two knobs 47 are separately arranged in the opening 49. The brush support 43 is positioned in the direction along the axis A <b> 1 by the pair of arcuate surfaces 44 coming into contact with the edge portion 48 and the restriction portion 38.

  Next, an electric circuit of the electric motor 17 will be described with reference to FIGS. The main switch 63 is accommodated in the casing 89, and the casing 89 is disposed in the handle 11. The handle 11 is extended from the housing 12 in a direction intersecting with the axis A1. The casing 89 is made of an insulating material, for example, a synthetic resin. The main switch 63 includes contacts 64 and 65 connected to the power cable 15. The main switch 63 includes a contact 66 connected to the coil 23A and a contact 67 connected to the coil 23B. The main switch 63 includes connection pieces 68 and 69. When an operator applies an operating force to the trigger 62, the connection piece 68 connects the contact 64 and the contact 66, and the connection piece 69 and the contact 65. The contact 67 is connected. That is, the main switch 63 connects a path between the AC power supply 90 and the forward / reverse selector switch 70. On the other hand, when the operating force applied to the trigger 62 is released by the operator, the contact 64 and the contact 66 are released, and the contact 65 and the contact 67 are released. That is, the main switch 63 blocks the path between the AC power supply 90 and the forward / reverse selector switch 70.

  A casing 83 is provided inside the handle 11. The casing 83 is formed of an insulating material such as synthetic resin. The forward / reverse selector switch 70 is provided in the casing 83. The forward / reverse selector switch 70 includes a contact 72 connected to the brush 51 via a lead wire 71 and a contact 74 connected to the brush 53 via a lead wire 73. Further, the forward / reverse changeover switch 70 includes a connection piece 75 connected to the contact point 72 and a connection piece 76 connected to the contact point 74.

  Further, contacts 77 and 78 are provided which are connected to the coil 23A via the lead wire 85 and arranged in parallel with each other. Contacts 79 and 80 are provided which are connected to the coil 23B via a lead wire 86 and arranged in parallel with each other. In addition, an operation member 81 for operating the connection pieces 75 and 76 is provided, and a projection 82 is provided on the operation member 81. The operating member 81 is disposed in the casing 83, and the protrusion 82 is exposed outside the casing 83. The connection pieces 75 and 76 are switched to a plurality of states, that is, the first state to the third state, by the operation member 81 operating.

  In the first state of the connection piece 75, the connection piece 75 is separated from the contact points 77 and 80, and in the first state of the connection piece 76, the connection piece 76 is separated from the contact points 78 and 79. In the second state of the connection piece 75, the connection piece 75 is connected to the contact 77 and is separated from the contact 80. In the second state of the connection piece 76, the connection piece 76 is connected to the contact 79 and is separated from the contact 78. In the third state of the connection piece 75, the connection piece 75 is connected to the contact 80 and is separated from the contact 77. In the third state of the connection piece 76, the connection piece 76 is connected to the contact 78 and is separated from the contact 79. The operation member 81 is an element of the forward / reverse selector switch 70.

  Next, a usage example of the electric working machine 10 will be described. The operator holds the handle 11 with his hand. As shown in FIGS. 7 and 10, when the brush support 43 is in the first operation position, the brushes 51 and 53 contact the commutator 30 with the axis C1 as the center. Even if the operator applies an operating force to the trigger 62, the trigger 88 does not operate because the stopper 88 contacts the block portion 56. That is, the contact 64 and the contact 66 are separated, and the contact 65 and the contact 67 are separated. Further, both the convex portions 57 and 58 are separated from the projection portion 82, the connecting piece 76 is separated from the contacts 78 and 79, and the connecting piece 75 is separated from the contacts 77 and 80. Therefore, the voltage of the AC power supply 90 is not applied to the brushes 51 and 53, and the rotor 19 is stopped.

  On the other hand, when the rotor 19 is rotated forward, the operator grasps the brush support 43 by hand and rotates it by a predetermined angle in the counterclockwise direction from the first operation position in FIG. Stops at the second operation position shown in FIG. When the brush support 43 rotates counterclockwise in FIG. 7, the convex portion 57 is pressed against the projection portion 82, and the operation member 81 operates. The operation member 81 operates in conjunction with the operation of the brush support 43. By the operation of the operation member 81, the connection piece 75 is connected to the contact 77 and leaves the contact 80. Further, the connection piece 76 is connected to the contact 79 and is separated from the contact 78 by the operation of the operation member 81. Therefore, the coil 23A is connected to the brush 51 via the lead wires 71 and 85, and the coil 23B is connected to the brush 53 via the lead wires 86 and 73.

  When the operator rotates the brush support 43 counterclockwise in FIG. 7, the brush support 43 rotates clockwise by a predetermined angle in FIG. 10, and stops at a predetermined position as shown in FIG. That is, the stopper 88 and the slit 55 are in the same position in the circumferential direction centering on the axis A1. For this reason, when an operator applies an operating force to the trigger 62, the stopper 88 enters the slit 55, and the trigger 62 operates.

  When the trigger 62 operates, the main switch 63 is turned on. That is, the connection piece 68 is connected to the contact point 64, the connection piece 69 is connected to the contact point 65, the voltage of the AC power supply 90 is applied to the brushes 51 and 53, and the rotating magnetic field is generated by the interaction between the stator 18 and the armature 29. And the rotor 19 rotates. The rotation direction of the rotor 19 is clockwise in FIG. 8, and the rotation direction is referred to as normal rotation. The torque of the rotor 19 is transmitted to the chuck 20 via the speed reduction mechanism, and the work tool rotates in a predetermined direction.

  Further, when the brush support 43 stops at the second operation position in FIG. 8, the brushes 51 and 53 come into contact with the commutator 30 around the axis C <b> 2. That is, when the brush support 43 is stopped at the second operation position in FIG. 8, the contact positions of the brushes 51 and 53 with respect to the commutator 30 are when the brush support 43 is stopped at the first operation position as shown in FIG. In comparison, the rotor 19 moves in the circumferential direction by an angle θ1 opposite to the rotation direction of the rotor 19.

  If the operating force applied to the trigger 62 is reduced from the state where the brush support 43 is stopped at the second position and the operating force is applied to the trigger 62 to transmit the torque to the work tool, the main switch 63 is turned off. Is done. That is, no voltage is applied to the brushes 51 and 53, and the rotor 19 stops. That is, the trigger 62 switches between rotation and stop of the electric motor 17.

  On the other hand, when the rotor 19 is rotated in the reverse direction, the operator grasps the brush support 43 with his hand and rotates it clockwise by a predetermined angle from the first operation position in FIG. Stop at the operating position. When the brush support 43 rotates in the clockwise direction in FIG. 7, the convex portion 58 is pressed against the protruding portion 82 and the operation member 81 operates. By the operation of the operation member 81, the connection piece 75 is connected to the contact 80 and is separated from the contact 77. Further, the connection piece 76 is connected to the contact 78 and is separated from the contact 79 by the operation of the operation member 81. Accordingly, the coil 23A is connected to the brush 53 via the lead wires 73 and 85, and the coil 23B is connected to the brush 51 via the lead wires 86 and 71.

  When the operator rotates the brush support 43 clockwise in FIG. 7, the brush support 43 rotates counterclockwise by a predetermined angle in FIG. 10 and stops at a predetermined position as shown in FIG. That is, the stopper 88 and the slit 54 are in the same position in the circumferential direction centering on the axis A1. For this reason, when an operator applies an operating force to the trigger 62, the stopper 88 enters the slit 54 and the trigger 62 operates.

  When the trigger 62 operates, the main switch 63 is turned on. That is, the connection piece 68 is connected to the contact point 64, the connection piece 69 is connected to the contact point 65, the voltage of the AC power supply 90 is applied to the brushes 51 and 53, and the rotating magnetic field is generated by the interaction between the stator 18 and the armature 29. Is formed, and the rotor 19 and the output shaft 28 rotate integrally. The rotation direction of the rotor 19 is counterclockwise in FIG. 9, and the rotation direction is referred to as reverse rotation. The torque of the rotor 19 is transmitted to the chuck 20 via the speed reduction mechanism, and the work tool rotates in the direction opposite to that shown in FIG.

  Further, when the brush support 43 stops at the third operation position in FIG. 9, the brushes 51 and 53 come into contact with the commutator 30 around the axis C <b> 3. That is, when the brush support 43 stops at the third operation position in FIG. 9, the contact position of the brushes 51 and 53 with respect to the commutator 30 is when the brush support 43 stops at the first operation position as shown in FIG. Compared with the rotation direction of the rotor 19, it moves in the circumferential direction by an angle θ2 in the opposite direction to the rotation direction of the rotor 19.

  If the operating force applied to the trigger 62 is reduced from the state where the brush support 43 is stopped at the third operating position and the operating force is applied to the trigger 62 to transmit the torque to the work tool, the main switch 63 Is turned off. That is, no voltage is applied to the brushes 51 and 53, and the rotor 19 stops.

  As described above, when the brush support 43 is stopped at the second operation position in FIG. 8 and the brush support 43 is stopped at the third operation position in FIG. The direction of rotation of the brush support 43 is opposite, but the angle θ1 and the angle θ2 are equal. In the electric working machine 10 according to the present embodiment, when the rotation direction of the rotor 19 is switched between forward rotation and reverse rotation, the contact positions of the brushes 51 and 53 with respect to the commutator 30 move in the circumferential direction of the rotor 19. .

  Next, the amount of the gap formed between the inner surfaces of the arc portions 44A and 44B of the brush support 43 and the outer surfaces of the guide rails 32A and 32B will be described with reference to FIGS. More specifically, it is the amount of radial gap formed between the flat surfaces 102A, 102B, and 102C and the outer surface of the guide rail 32A. The flat surfaces 104A, 104B, and 104C, and the outer surface of the guide rail 32B It is the amount of gaps in the radial direction formed between the two.

  When the brush support 43 stops at the first operation position as shown in FIG. 13, the arc surface 100A is located inside the arc surface 103A and the flat surface 100C is located inside the flat surface 102B in the radial direction about the axis A1. Is located, and the arcuate surface 100B is located inside the arcuate surface 103B. Further, in the radial direction centering on the axis A1, the arc surface 101A is located inside the arc surface 105A, the flat surface 101C is located inside the flat surface 104B, and the arc surface 101B is located inside the arc surface 105B. . There is a gap amount G1 between the arc surface 103A and the arc surface 100A, and there is a gap amount G1 between the arc surface 103B and the arc surface 100B. Further, there is a gap amount G1 between the arc surface 105A and the arc surface 101A, and there is a gap amount G1 between the arc surface 105B and the arc surface 101B. The gap amount G1 is the minimum value of the gap amount formed between the outer surfaces of the guide rails 32A and 32B and the inner surfaces of the arc portions 44A and 44B. The gap amount G1 is a value obtained by dividing the radius L4 from the radius L4.

  When the brush support 43 stops at the second operation position as shown in FIG. 14, the arc surface 100A is located inside the flat surface 102A and the flat surface 100C is located inside the arc surface 103A in the radial direction centering on the axis A1. Is located, and the arcuate surface 100B is located inside the flat surface 102B. Further, the arc surface 101A is located inside the flat surface 104B, the flat surface 101C is located inside the arc surface 105B, and the arc surface 101B is located inside the flat surface 104C. There is a gap amount G2 between the flat surface 102B and the arc surface 100B, and there is a gap amount G2 between the flat surface 102A and the arc surface 100A. Further, there is a gap amount G2 between the flat surface 104B and the arc surface 101A, and there is a gap amount G2 between the flat surface 104C and the arc surface 101B. The gap amount G2 is the minimum value of the gap amount formed between the outer surfaces of the guide rails 32A and 32B and the inner surfaces of the arc portions 44A and 44B. The gap amount G2 is a value obtained by dividing the radius L1 from the distance L3.

  When the brush support 43 stops at the third operation position as shown in FIG. 15, the arc surface 100A is positioned inside the flat surface 102B in the radial direction centered on the axis A1, and the flat surface 100C is positioned inside the arc surface 103B. Is located, and the circular arc surface 100B is located inside the flat surface 102C. Further, the arc surface 101B is located inside the flat surface 104B, the flat surface 101C is located inside the arc surface 105A, and the arc surface 101A is located inside the flat surface 104A.

  There is a gap amount G2 between the flat surface 102B and the circular arc surface 100A, and there is a gap amount G2 between the flat surface 102C and the circular arc surface 100B. Further, there is a gap amount G2 between the flat surface 104A and the arc surface 101A, and there is a gap amount G2 between the flat surface 104B and the arc surface 101B. The gap amount G2 is the minimum value of the gap amount formed between the outer surfaces of the guide rails 32A and 32B and the inner surfaces of the arc portions 44A and 44B. The gap amount G2 is a value obtained by dividing the radius L1 from the distance L3.

In this embodiment,
Distance L3 ≦ radius L1 <radius L4
And,
Distance L2 <Distance L3
It is.

Therefore, the gap amount G2 when the operation position of the brush support 43 is the second operation position or the third operation position where the rotor 19 is rotated forward or reverse is the same as the operation amount of the brush support 43. It is smaller than the gap amount G1 in the case of the first operation position. That is, when the rotor 19 is rotating, the inner surface of the arc portion 44A is in contact with the outer peripheral surface of the guide rail 32A, and the inner surface of the arc portion 44B is in contact with the outer peripheral surface of the guide rail 32B. In this case,
Distance L3 = radius L1
It becomes the relationship. For this reason, the brush support 43 is maintained coaxial with the housing 12.

  Therefore, when the rotor 19 rotates, the brush support 43 can be prevented from moving in the radial direction with respect to the housing 12. For this reason, wear of the brushes 51 and 53 and wear of the commutator 30 can be suppressed. Therefore, the life of the brushes 51 and 53 is lengthened, and the life of the commutator 30 is lengthened. Moreover, it can suppress that the contact pressure of the brushes 51 and 53 with respect to the commutator 30 changes, and the commutation effect | action of the commutator 30 is stabilized.

  A correspondence relationship between the configuration described in this embodiment and the configuration of the present invention will be described. The electric motor 17 corresponds to the electric motor of the present invention, the rotor 19 corresponds to the rotor of the present invention, the electric work machine 10 corresponds to the electric work machine of the present invention, and the housing 12 corresponds to the housing of the present invention. The axis A1 corresponds to the axis of the present invention, the brush support 43 corresponds to the switching member of the present invention, the gap amounts G1 and G2 correspond to the amount of the gap in the present invention, and the flat surface 100C. , 101C, 102A, 102B, 102C, 104A, 104B, 104C, and circular arc surfaces 100A, 100B, 101A, 101B, 103A, 103B, 105A, 105B correspond to the gap amount adjusting mechanism of the present invention.

  The armature 29 corresponds to the armature of the present invention, the brushes 51 and 53 correspond to the brush of the present invention, the arc portions 44A and 44B correspond to the first guide portion of the present invention, the guide rails 32A, 32B corresponds to the second guide portion of the present invention. Further, the flat surfaces 102A, 102B, 102C, 104A, 104B, 104C correspond to the first flat surface or the second portion of the present invention, and the arc surfaces 103A, 103B, 105A, 105B correspond to the first arc surface of the present invention. Or it corresponds to the first part. Further, the flat surfaces 100C and 101C correspond to the second flat surface or the fourth portion of the present invention, and the arc surfaces 100A, 100B, 101A and 101B correspond to the second arc surface or the third portion of the present invention.

  Further, the first operation position of the brush support 43 corresponds to the “position where the rotor is stopped” or the “first position” of the present invention, and the second operation position and the third operation position of the brush support 43 are the present invention. This corresponds to a “position for rotating the rotor” or a “second position”. Further, the radius L1 is the first radius of the present invention, the radius L4 is the second radius of the present invention, the distance L2 is the first distance of the present invention, and the distance L3 is the second radius of the present invention. Distance. Further, the portion having the radius L4 in the brush support 43 is the first portion of the present invention, and the brush support 43 corresponds to the flat surfaces 102A, 102B, and 102C having the radial distance L3 between the axis A1. The part is the second part of the present invention. The portion corresponding to the radius L1 of the guide rails 32A and 32B provided in the housing 12 is the third portion of the present invention, and the portion corresponding to the distance L2 is the fourth portion of the present invention. The distances L2 and L3 and the radii L1 and L4 correspond to the radial dimensions in the present invention. The brushes 51 and 53 correspond to the energizing brush of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the housing containing the rotor in the present invention means that at least a part in the length direction of the rotor is contained. The electric working machine of the present invention includes a driver and a drill. When the electric working machine is a drill, the object can be cut by rotating the work tool to form holes and grooves in the object. When the electric working machine is a driver, the screw member and the bolt can be tightened or loosened by forward rotation or reverse rotation of the work tool. When the electric working machine is a sander or a grinder, when the grindstone, brush, or diamond cutter as the working tool is rotated forward or reverse, the working tool grinds or polishes the object. Furthermore, the present invention includes an electric working machine in which the rotor and the holding member are arranged eccentrically, and an electric working machine in which the rotor and the holding member are arranged concentrically.

  Further, in FIGS. 7 to 9 which are left side views of the electric working machine as viewed from the handle side, for the sake of convenience, the clockwise rotation is the forward rotation of the rotor and the counterclockwise rotation is the reverse rotation of the rotor. On the other hand, in FIGS. 7 to 9 which are left side views of the electric working machine from the handle side, it is possible to grasp the counterclockwise direction as the forward rotation of the rotor and the clockwise direction as the reverse rotation of the rotor. is there. The power source for applying a voltage to the electric motor of the present invention may be either an AC power source or a DC power source. The direct current power source includes a battery pack that is attached to and detached from the housing. The battery pack has a battery cell accommodated in a case. Furthermore, the contact which switches the direction of the electric current which flows into an armature by rotation of a switching member may be provided in the brush support and the housing.

  DESCRIPTION OF SYMBOLS 10 ... Electric working machine, 12 ... Housing, 17 ... Electric motor, 19 ... Rotor, 29 ... Armature, 32A, 32B ... Guide rail, 43 ... Brush support, 44A, 44B ... Arc part, 51, 53 ... Brush, 62 ... Trigger, 100A, 100B, 101A, 101B, 103A, 103B, 105A, 105B ... arc surface, 100C, 101C, 102A, 102B, 102C, 104A, 104B, 104C ... flat surface, A1 ... axis, G1, G2 ... gap amount .

Claims (13)

An electric work machine capable of switching between rotation and stop of a rotor of an electric motor,
A trigger operated by an operator to switch between rotation and stop of the rotor;
A housing containing the rotor;
A first position that is rotatably attached to the housing about the axis of the rotor and that does not rotate the rotor even when the trigger is operated; a second position where the rotor rotates when the trigger is operated; A switching member that can be switched to,
Have
The switching member includes a first guide portion arranged in a circumferential direction around the axis,
The housing includes a second guide portion that is arranged in a circumferential direction around the axis, and that positions the switching member in a radial direction around the axis in cooperation with the first guide portion,
The second guide part is disposed inside the first guide part in a radial direction around the axis,
A gap is formed between the inner surface of the first guide portion and the outer surface of the second guide portion in a radial direction centered on the axis.
The electric working machine in which the gap amount when the switching member is in the second position is smaller than the gap amount when the switching member is in the first position. The rotor includes an armature that is energized to form a rotating magnetic field,
2. The switching member supports two energizing brushes that contact the armature, and changes the direction of current with respect to the two energizing brushes when rotated with respect to the housing. The electric working machine as described in. The inner surface includes a first portion and a second portion having different radial dimensions around the axis, and the second portion is configured to have a smaller dimension than the first portion.
The outer surface includes a third portion and a fourth portion having different radial dimensions around the axis,
The electric working machine according to claim 1 or 2 , wherein the fourth portion has a smaller size than the third portion . 4. The electric work according to claim 3, wherein the second portion and the third portion overlap at least a part of an arrangement range in a circumferential direction around the axis when the switching member is in the second position. Machine. A gap amount adjusting mechanism is provided to reduce the gap amount when the switching member is in the second position, rather than the gap amount when the switching member is in the first position;
The gap amount adjusting mechanism is
A first flat surface and a first arcuate surface arranged along the circumferential direction around the axis on the inner surface of the first guide portion;
A second flat surface and a second arc surface arranged along the circumferential direction centering on the axis on the outer surface of the second guide portion;
The electric working machine according to claim 1, comprising: When the switching member is in the second position, the second arc surface is located inside the first flat surface in the radial direction, and the second flat surface is located inside the first arc surface. Position to,
When the switching member is in the first position, the second flat surface is located inside the first flat surface in the radial direction, and the second arc surface is located inside the first arc surface. Position to,
When the switching member is in the second position, the gap amount formed between the first flat surface and the second arc surface is the same as when the switching member is in the first position. The electric working machine according to claim 5 , wherein the electric working machine is smaller than an amount of the gap formed between the first arc surface and the second arc surface . The first guide part is arranged at two points that are point-symmetric in the circumferential direction around the axis,
The second guide portion is disposed at two locations that are point-symmetric in the circumferential direction about the axis,
The two current-carrying brushes, electric working machine according to one by one are arranged, according to claim 2 between the second guide portions in the circumferential direction around the axis. The electric working machine according to claim 1, wherein the rotor can be switched between forward rotation and reverse rotation . The electric working machine according to claim 8 , wherein the switching member has a different rotation direction with respect to the housing when the rotor rotates forward and when the rotor rotates reversely . An electric work machine capable of switching between rotation and stop of a rotor of an electric motor,
A housing that supports the rotor;
A switching member provided to be rotatable about the axis of the rotor with respect to the housing, and for switching between rotation and stop of the rotor;
A first guide portion disposed in a circumferential direction around the axis on the switching member;
A second guide part disposed in a circumferential direction around the axis in the housing, and disposed inside the first guide part; and
A first flat surface and a first arc surface provided on an inner surface of the first guide portion and disposed along a circumferential direction centering on the axis;
A second flat surface and a second arc surface provided on an outer surface of the second guide portion and arranged along a circumferential direction centering on the axis;
With
A first radius of the second arcuate surface about the axis;
A second radius of the first arcuate surface about the axis;
The shortest first distance from the axis to the second flat surface;
The shortest second distance from the axis to the first flat surface;
The magnitude relationship between
Second distance ≦ first radius <second radius,
And,
1st distance <2nd distance,
An electric work machine. The first guide part is arranged at two points that are point-symmetric in the circumferential direction around the axis,
The second guide portion is disposed at two locations that are point-symmetric in the circumferential direction about the axis,
The rotor includes an armature that is energized to form a rotating magnetic field,
The switching member supports two energizing brushes in contact with the armature, and when rotated with respect to the housing, changes the direction of the current with respect to the two energizing brushes,
11. The electric working machine according to claim 10, wherein the two brushes for energization are arranged one by one between the first guide portions in a circumferential direction around the axis . The electric working machine according to claim 10 or 11, wherein the rotor can be switched between forward rotation and reverse rotation . The electric working machine according to claim 12, wherein the switching member has a different rotation direction with respect to the housing depending on whether the rotor rotates normally and when the rotor rotates reversely .

Images