JP2011031335A - Power tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a durability of a click spring. <P>SOLUTION: A power tool includes a motor, a housing for accommodating the motor, a tip tool holding part rotated by the motor and a clutch mechanism provided between the motor and a tip tool to adjust an output to the tip tool from the motor. The clutch mechanism includes a clutch ring rotating relative to the housing to adjust the output, a recessed part provided in the clutch ring and the click spring having a protruding part engaged with the recessed part. The click spring is held by one side. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power tool. In particular, the present invention relates to a power tool having a clutch capable of adjusting torque transmitted from a motor to an output shaft.

  A conventional clutch mechanism will be described with reference to FIGS.

  In the conventional clutch mechanism, by rotating the clutch ring 150 with respect to the spindle case 134, the elastic force pushing the ring gear 30 by the coil spring constituting the clutch is adjusted.

  The elastic force generated by the coil spring is determined by how much the clutch ring 150 rotates relative to the spindle case 134. For this reason, a click spring 137 is provided to inform the operator how much the clutch ring 150 has rotated with respect to the spindle case 134.

  The click spring 137 was held at both ends by the spindle case 134.

JP 2002-233968 A

  In the conventional click spring configuration described above, the following improvements have been desired.

  First, the convex portion 137A of the click spring is plastically deformed by the concave portion of the clutch ring 150 and may be damaged.

  Secondly, the same force is applied to the click spring both when the coil spring is loosened to reduce torque transmission and when the coil spring is tightened to increase torque transmission. During the work, the clutch ring 50 may rotate unexpectedly due to the elastic force of the coil spring. This is because the coil spring is compressed by the output, and the click spring 37A is deformed by the compression.

  An object of the present invention is to provide a highly durable power tool in which a click spring is not easily damaged.

  Another object of the present invention is to provide a power tool in which the click spring is less likely to rotate unexpectedly.

  The above object is provided between the motor and the tip tool, and adjusts the output from the motor to the tip tool, provided with a motor, a housing that houses the motor, a tip tool holding portion that is rotated by the motor, A clutch mechanism that adjusts the output by rotating with respect to the housing, a recess provided in the clutch ring, and a protrusion that engages with the recess. This can be achieved by a power tool having a click spring having a portion, wherein the click spring is held in a cantilever manner.

  Also, a motor, a housing that houses the motor, a tip tool holding portion that is rotated by the motor, and a clutch that is provided between the motor and the tip tool and that can adjust the output from the motor to the tip tool. A clutch ring that adjusts the output by rotating with respect to the housing, a recess provided in the clutch ring, and a convex portion that engages with the recess. A power tool having a click spring, wherein when the clutch ring is rotated to one side, the holding force of the clutch ring by the click spring is different between when the clutch ring is rotated to the other side. It can achieve by the power tool characterized by comprising.

  Since the click spring is held in a cantilever manner, the distance from the click spring convex portion to the click spring holding portion can be increased. For this reason, the distance from the convex part to which a force is applied to the holding part is increased, and the click spring is less likely to be damaged by plastic deformation.

  In addition, the clutch ring is held differently when the clutch ring is rotated to one side and when the clutch ring is rotated to the other side. The ring is less likely to rotate unexpectedly.

Driver drill showing an embodiment of the present invention 1 is an enlarged view of the main part of FIG. The figure which shows the state which rotated the clutch ring of FIG. 2 and compressed the coil spring. AA line arrow view of FIG. The top view of the click spring which comprises embodiment of this invention Front view of a click spring constituting an embodiment of the present invention BB line view of FIG. Figure when trying to rotate the clutch ring of FIG. 7 clockwise The figure when the clutch ring of FIG. 7 is rotated clockwise Figure when trying to rotate the clutch ring of FIG. 7 counterclockwise Figure when the clutch ring of Fig. 7 is rotated counterclockwise Cross section of the main part of a conventional driver drill The figure when it rotates clockwise in the principal part sectional view of the conventional driver drill

  An embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a rechargeable electric driver drill 100 which is an embodiment of a power tool of the present invention.

  The driver drill 100 has a housing 1.

  The housing 1 includes a motor housing 1A, a handle housing 1B extending downward from the motor housing 1A, and a battery connection housing 1C provided below the handle housing 1B.

  A brushless motor 4 is accommodated in the motor housing 1A.

  The brushless motor 4 includes a stator 4A and a rotor 4B that can rotate inside the stator 4A. Six coils 4A1 are wound around the stator 4A and fixed.

  A circuit board 5 is disposed behind the stator 4A, and the circuit board 5 is fixed to the stator 4A with screws.

  The circuit board 5 is provided with six FETs (field effect transistors) 6 which are switching elements. The FET 6 energizes the coil 4A1.

  The rotor 4B has four permanent magnets 4B1. A rotation shaft 4B2 extending in the front-rear direction is fixed to the rotor 4B.

  A bearing 8A is provided at the rear of the motor housing 1A, and holds the rear of the rotating shaft 4B2 of the rotor 4B.

  An inner cover 9 is held in the motor housing so as not to rotate. The inner cover 9 holds a bearing 8B. The rotating shaft 4B2 is rotatably held inside the motor housing 1A by a bearing 8A.

  A cooling fan 7 is fixed to the rotating shaft 4B2. The rotating shaft 4B2 in front of the cooling fan 7 is rotatably held inside the motor housing 1A by a bearing 8B.

  A gear case 19 fixed to the inner cover 9 is provided in front of the inner cover 9.

  The pinion 20 is fixed to the rotating shaft 4B2 in front of the bearing 8B of the rotating shaft 4B2. A gear is provided on the outer periphery of the pinion 20.

  A plurality of planetary gears A <b> 21 are provided so as to mesh with the gears of the pinion 20. In this embodiment, there are four planetary gears, but there may be three, five, or more.

  A ring gear A22 provided in an annular shape so as to mesh with the planetary gear 21 is fixed to the gear case. The gear of the ring gear A22 is provided on the inner periphery.

  A carrier A23 is provided so as to hold the rotating shaft of the planetary gear A21. A sun gear A24 is provided at the front of the carrier.

  A plurality of planetary gears B25 are provided so as to mesh with the sun gear A24. Any number of planetary gears B may be used.

  A ring gear B26 that is movable in the front-rear direction is provided so as to mesh with the planetary gear B25. At the front position, the ring gear B26 is engaged with the gear case 19, the protrusion 27, and the outer periphery, and cannot rotate. In the rear position, the ring gear B26 can rotate without the gear case 19, the projection and the outer periphery engaging with each other.

  A carrier B28 is provided to hold the rotating shaft of the planetary gear 25. The gear in front of the gear rear B meshes with a plurality of planetary gears C29.

  The pinion 20, the planetary gear 21, the ring gear A22, the carrier A23, the sun gear A24 and the planetary gear B25 are arranged so as to be accommodated in the gear case 19.

  A ring gear C30 is provided so as to mesh with the planetary gear C29.

  The front surface of the ring gear C30 is provided with unevenness (not shown). A needle 31 is provided so as to engage with the unevenness. Six needles 31 are provided. Other numbers may be used.

  The needle 31 receives an elastic force from the front by a coil spring 32. The needle is inserted into six holes 34B provided in the spindle case 34 and protrudes from the rear.

  The front of the coil spring 32 is held by a nut 33.

  A first screw is cut on the inner periphery of the nut 33.

  The spindle case 34 is provided with a second screw so as to be screwed with the first screw. The spindle case 34 is fixed to the motor housing 1A.

  The spindle case 34 is provided with a bearing 8C, and the spindle 35 is rotatably held by the bearing 8C.

  A clutch ring 50 is provided so as not to rotate with the nut 33.

  A tip tool holding unit 40 is provided in front of the spindle 35. The tip tool holding portion 40 is provided with a tip tool grasping portion 40A so that a tip tool (not shown) can be held.

  A shift switch 36 is provided on the upper portion of the motor housing 1A so that the ring gear B26 can be moved forward and backward. Thereby, the ratio of the rotation of the rotor 4B and the rotation of the tip tool 40 can be changed.

  A trigger 3 is provided at an upper front portion of the handle housing 1B. A switch unit 3A is provided behind the trigger 3.

  A code A13 is provided so as to electrically connect the trigger 3 and the circuit board 5.

  A battery connection housing 1C is provided below the grip housing 1B. A control circuit board 10 is provided inside the battery connection housing 1C. The control circuit board is electrically connected to the light 11 with a cord. The light 11 can illuminate the vicinity of the tip tool holding portion 40.

  The circuit board 5 and the control circuit board 10 are electrically connected by a cord 14. The switch unit 3A and the control circuit board are electrically connected by a cord 12.

  A terminal protrudes from below the battery connection housing 1 </ b> C, and this terminal and the battery 2 are connected. Electric power can be supplied from the battery cell in the battery 2 to the motor via the terminal.

  The battery 2 can be detached from the battery connection housing 1C by operating the operation unit 2A.

  With reference to FIG.2 and FIG.3, the operation | movement by rotating the clutch ring 50 is demonstrated. When the clutch ring 50 is rotated, the clutch ring connecting portion fixed behind the clutch ring is rotated. The nut 33 fixed to the clutch ring connecting portion 51 also rotates. Since the nut 33 and the spindle case 34 are screwed together with a screw, the nut 33 is moved rearward by the rotation of the clutch ring 50 and the rotation of the nut 33 (see FIG. 3).

  As shown in FIG. 2, when the nut 33 is in front, the compression amount of the coil spring 32 is small. For this reason, the force which presses the ring gear C30 with the coil spring 32 is weak.

  When the nut moves backward as shown in FIG. 3, the compression amount of the coil spring 32 is large. For this reason, the force which presses the ring gear C30 with the coil spring 32 is strong.

  The ring gear C is held unrotatable by the needle 31, but rotates when the force pressing the ring gear C30 by the coil spring is weak and the reaction force from the tip tool is large. For this reason, the tip tool cannot be rotated.

  When the force that presses the ring gear C30 by the coil spring is strong, the ring gear C30 does not rotate even when the reaction force from the tip tool is large. For this reason, the tip tool can continue to rotate.

  4 is a view taken along the line AA in FIG. As shown in this figure, a click spring 37 is provided so as to be sandwiched between the inner peripheral surface of the motor housing 1 </ b> A and the outer peripheral surface of the spindle case 34. For this reason, the click spring 37 does not move radially outward. In addition, six holes 34B of the spindle case 34 are shown. A spindle 35 is disposed in the spindle case 34 so as to be rotatable.

  FIG. 5 is a plan view of the click spring 37. The click spring 37 is provided with a convex portion 37A. A hole 37D is also provided.

  FIG. 6 shows a front view of the click spring 37. An inflection point 37C is provided between the hole portion 37D and the convex portion 37A. The hole 37D side is substantially arcuate from the inflection point 37C, and the convex portion 37 side is substantially linear from the inflection point 37C. For this reason, the convex portion 37A is positioned on the outer side in the radial direction than in the case where the linear portion has an arc shape. Thus, since the position of the convex portion is arranged on the outer side in the radial direction, the concave portion 51A described later and the convex portion 37A are firmly engaged.

  FIG. 7 shows a view taken along line BB in FIG. A plurality of recesses 51 </ b> A are provided in the clutch ring connection portion 51 that is fixed to the clutch ring 50 so as not to rotate. The convex portion 37A is engaged with one of the concave portions 51A. The clutch ring 50 and the clutch ring connecting portion 51 are referred to as a clutch ring portion.

  The click spring 37 is fixed to the spindle case 34 through a hole 37D. The spindle case is provided with a convex portion 34D, and a hole portion 37D is inserted into the convex portion 34D. In addition, a hole is formed in the center of the spindle case 334, and the spindle 35 is rotatably arranged. A recess 34C is provided in the outer periphery of the spindle case 34 where the click spring 37 is disposed, and is configured not to contact the spindle case 34 when the click spring 37 is deformed. .

  FIG. 8 shows the relationship between the force between the click spring 37 and the clutch ring connecting portion 51 when the clutch ring connecting portion 51 is rotated clockwise by rotating the clutch ring 50 clockwise. As shown in the figure, the clutch ring connecting portion 51 rotates in the direction of arrow C. By rotating the clutch ring connection part 51, the first contact part 51 </ b> A <b> 1 of the recess 51 </ b> A of the clutch ring connection part 51 comes into contact with the first contact part 37 </ b> A <b> 1 of the click spring 37. At this time, the click spring 37 receives a force from the first contact portion 51A1 in the direction indicated by the arrow D with the rotation center 37E as the rotation center. At this time, the moment to be applied to the clutch ring connecting portion 51 is obtained by multiplying the force P1 to rotate clockwise by the distance L1 in the direction orthogonal to the force P1 from the rotation center 37E to the first contact portion 37A1. Is. For this reason, when rotating clockwise, the clutch ring connection part 51 can be rotated with a weak force. For this reason, the clutch ring 51 can be rotated with a weak force P1.

  In addition, the figure at the time of rotating the clutch ring connection part 51 in FIG. 9 is shown. The convex portion 37A is not engaged with the concave portion 51A.

  FIG. 10 shows the relationship between the force of the click spring 37 and the clutch ring connecting portion 51 when the clutch ring connecting portion 51 is rotated counterclockwise by rotating the clutch ring 50 counterclockwise. As shown in the figure, the clutch ring connecting portion 51 rotates in the direction of arrow E. By rotating the clutch ring connection portion 51, the second contact portion 51 </ b> A <b> 2 of the recess 51 </ b> A of the clutch ring connection portion 51 comes into contact with the first contact portion 37 </ b> A <b> 1 of the click spring 37. At this time, the click spring 37 receives a force shown by an arrow D from the second contact portion 51A2 with the rotation center 37E as the rotation center. At this time, the moment to be applied to the clutch ring connecting portion 51 is obtained by multiplying the force P2 for rotating counterclockwise by the distance L2 in the direction orthogonal to the force P2 from the rotation center 37E to the second contact portion 37A2. It is a thing. For this reason, when rotating counterclockwise, the clutch ring connecting portion 51 must be rotated with a strong force. For this reason, the clutch ring 51 can be rotated with a strong force.

  In addition, the figure at the time of rotating the clutch ring connection part 51 in FIG. 11 is shown. The convex portion 37A is not engaged with the concave portion 51A.

  As shown in FIG. 7, the click spring 37 is held by the spindle case 34 by a cantilever that is held by the convex portion 34D. For this reason, the distance from the convex part of the click spring to the holding part of the click spring can be increased. For this reason, the distance from the convex part to which a force is applied to the holding part is increased, and the click spring is less likely to be damaged by plastic deformation.

  The operation of the electric driver drill 1 configured as described above will be described.

  When the trigger 3 is pulled in while the battery 2 is charged and connected to the battery connection portion 1C, power is supplied from the battery cell to the brushless motor 4. When electric power is supplied to the brushless motor 4, electric power is supplied to the coil 4 </ b> A <b> 1 of the stator 4 of the brushless motor 4 via the FET 6.

  When the coil 4A1 is energized, the magnetic field generated by the coil 4A1 rotates the rotor 4B provided with the permanent magnet. The rotating shaft 4B2 fixed to the rotor 4B rotates. Thereby, rotation is transmitted in order, and the plurality of planetary gears C29 rotate. In a state where the tip tool is held by the grasping portion 40A of the tip tool holding unit 40, tightening is started on a tightened material such as wood while the tip tool is engaged with a tightening material such as a screw.

  As described above, the ring gear C30 is pressed backward by the needle 31. As shown in FIG. 2, when the nut 33 is in front, the force for pressing the needle 31 backward by the coil spring 32 is weak. For this reason, when the torque transmitted from the fastening material such as a screw to the tip tool holding portion 40 becomes larger than the torque for holding the ring gear C30 in the rotational direction via the needle 31 by the elastic force of the coil spring 32. The ring gear C30 starts to rotate. For this reason, the plurality of planetary gears C29 starts to rotate, and the tip tool holding portion 40 does not rotate. As shown in FIG. 3, when the nut 33 is moved backward by rotating the clutch ring 50, the force for pressing the needle 31 backward by the coil spring 32 is strong. For this reason, the torque that prevents the tip tool holding portion 40 from rotating is larger than that in the case shown in FIG.

  When the tip tool holding part 40 is rotated by operating the trigger 3, the clutch ring 50 may unexpectedly rotate via the clutch ring connection part 51. This is because the nut 33 rotates because the elastic force of the coil spring 32 gives the elastic force to the nut 33 in the forward direction.

  In order to reduce the unexpected rotation of the clutch ring 50, when the click spring 37 is cantilevered and the clutch ring 50 rotates clockwise in the direction of arrow C as shown in FIG. It was made possible to rotate at P1. Further, as shown in FIG. 3, when the clutch ring 50 rotates clockwise in the direction of arrow E, it can be rotated with a strong force P2.

  Therefore, when the clutch ring connection portion 51 is rotated counterclockwise by the coil spring 32 via the nut 33, the force P2 for rotating the clutch ring connection portion 51 from the click spring 37 is increased. For this reason, the clutch ring 50 is less likely to rotate unexpectedly via the clutch ring connecting portion 51.

  When the operator rotates the clutch ring 50 clockwise, the clutch ring can be rotated with a weak force P1, and the workability of the operator can be improved.

  In the present embodiment, the holding force of the clutch ring when rotating the clutch ring 50 in the clockwise direction and the counterclockwise direction of the click spring is different by cantilevering. It may be a form.

  For example, even if the click spring is held by both ends, the holding force of the click spring in the clockwise direction and the counterclockwise direction may be different. Specifically, the width of some of the click springs may be reduced. The thickness of the click spring may be reduced.

  Further, in this embodiment, the clutch ring connecting portion fixed to the rear side of the clutch ring is engaged with the convex portion of the click spring. However, the clutch ring is engaged with the convex portion of the click spring. You may make it do.

1 Driver drill, 2 Battery, 3 Trigger, 4 Brushless motor, 29 Planetary gear C, 30 Ring gear C, 31 Needle, 32 Coil spring, 33 Nut, 34 Spindle case, 35 Spindle, 37 Click spring, 40 Tip tool holder

Claims (2)

A motor,
A housing for housing the motor;
A tip tool holder rotated by the motor;
A clutch mechanism provided between the motor and the tip tool and capable of adjusting an output from the motor to the tip tool;
The clutch mechanism includes a clutch ring part that adjusts the output by rotating with respect to the housing, a concave part provided in the clutch ring part, and a click spring having a convex part engaged with the concave part. A power tool having
A power tool characterized by holding the click spring in a cantilever manner. A motor,
A housing for housing the motor;
A tip tool holder rotated by the motor;
A clutch mechanism provided between the motor and the tip tool and capable of adjusting an output from the motor to the tip tool;
The clutch mechanism includes a clutch ring part that adjusts the output by rotating with respect to the housing, a concave part provided in the clutch ring part, and a click spring having a convex part engaged with the concave part. A power tool having
The power that is configured such that the holding force of the clutch ring portion by the click spring is different between when the clutch ring portion is rotated to one side and when the clutch ring portion is rotated to the other side. tool.