Driver drill

A driver drill allows smooth change of the drive conditions of a motor. The driver drill includes a motor, an output unit located frontward from the motor and rotatable with a rotational force from the motor, a trigger lever operable to activate the motor, a forward-reverse switch lever operable to change a rotation direction of the motor, a first operation member operable to change a drive condition of the motor, a second operation member located upward from the first operation member and operable to change the drive condition of the motor, and a controller that sets the drive condition of the motor in response to an operation on at least one of the first operation member or the second operation member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Japanese Patent Application No. 2021-129435, filed on Aug. 6, 2021, the entire contents of which are hereby incorporated by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a driver drill.

2. Description of the Background

In the field of driver drills, a known driver drill is described in Japanese Unexamined Patent Application Publication No. 2021-045844.

BRIEF SUMMARY

To change the drive conditions of a motor included in a driver drill, an operator may intend to change the drive conditions of the motor smoothly while remaining in a working posture for using the driver drill.

One or more aspects of the present disclosure are directed to a driver drill that allows smooth change of the drive conditions of a motor.

A first aspect of the present disclosure provides a driver drill, including:a motor;an output unit located frontward from the motor and rotatable with a rotational force from the motor;a trigger lever operable to activate the motor;a forward-reverse switch lever operable to change a rotation direction of the motor;a first operation member operable to change a drive condition of the motor;a second operation member located upward from the first operation member, the second operation member being operable to change the drive condition of the motor; anda controller configured to set the drive condition of the motor in response to an operation on at least one of the first operation member or the second operation member.

A second aspect of the present disclosure provides a driver drill, including:a motor;an output unit located frontward from the motor and rotatable with a rotational force from the motor;a vibrator between the motor and the output unit, the vibrator being configured to switch the output unit between vibrating in a front-rear direction and not vibrating in the front-rear direction;a trigger lever operable to activate the motor;a forward-reverse switch lever operable to change a rotation direction of the motor;a motor housing accommodating the motor;a grip housing extending downward from the motor housing;an operation button on the motor housing, the operation button being operable to change a drive condition of the motor; anda controller configured to set the drive condition of the motor in response to an operation on the operation button.

The driver drill according to the above aspects of the present disclosure allows smooth change of the drive conditions of the motor.

DETAILED DESCRIPTION

Although one or more embodiments of the present disclosure will now be described with reference to the drawings, the present disclosure is not limited to the embodiments. The components in the embodiments described below may be combined as appropriate. One or more components may be eliminated.

In the embodiments, the positional relationships between the components will be described using the directional terms such as right and left (or lateral), front and rear (or forward and backward), and up and down (or vertical). The terms indicate relative positions or directions with respect to the center of a driver drill.

The driver drill includes a motor. In the embodiments, a direction parallel to a rotation axis AX of the motor is referred to as an axial direction for convenience. A direction about the rotation axis AX is referred to as a circumferential direction or circumferentially, or a rotation direction for convenience. A direction radial from the rotation axis AX is referred to as a radial direction or radially for convenience.

In the embodiments, the rotation axis AX extends in the front-rear direction. The axial direction corresponds to the front-rear direction. The axial direction is from the rear to the front (first axial direction) or from the front to the rear (second axial direction). A position nearer the rotation axis AX in the radial direction, or a radial direction toward the rotation axis AX, is referred to as radially inside or radially inward for convenience. A position farther from the rotation axis AX in the radial direction, or a radial direction away from the rotation axis AX, is referred to as radially outside or radially outward for convenience.

Overview of Driver Drill

FIG.1is a front perspective view of a driver drill1according to an embodiment.FIG.2is a rear perspective view of the driver drill1according to the embodiment.FIG.3is a side view of the driver drill1according to the embodiment.FIG.4is a sectional view of the driver drill1according to the embodiment. The driver drill1according to the embodiment is a vibration driver drill.

As shown inFIGS.1to4, the driver drill1includes a housing2, a rear cover3, a casing4, a battery mount5, a motor6, a power transmission7, an output unit8, a fan9, a trigger lever10, a forward-reverse switch lever11, a speed switch lever12, a mode switch ring13, a light unit14, an interface panel15, a dial16, a hand switch17, and a controller18.

The housing2is formed from a synthetic resin. The housing2in the embodiment is formed from nylon. The housing2includes a left housing2L and a right housing2R. The left and right housings2L and2R are fastened together with screws2S to form the housing2.

The housing2includes a motor compartment21, a grip22, and a battery holder23.

The motor compartment21accommodates the motor6. The motor compartment21is cylindrical.

The grip22is grippable by an operator. The grip22is located below the motor compartment21. The grip22extends downward from the motor compartment21. The trigger lever10is located in a front portion of the grip22.

The battery holder23accommodates the controller18. The battery holder23is located below the grip22. The battery holder23is connected to a lower end of the grip22. The battery holder23has larger outer dimensions than the grip22in the front-rear and lateral directions.

The rear cover3is formed from a synthetic resin. The rear cover3is located behind the motor compartment21. The rear cover3accommodates the fan9. The rear cover3covers a rear opening of the motor compartment21. The rear cover3is fastened to the motor compartment21with screws3S.

The motor compartment21has inlets19A. The rear cover3has outlets19B. Air outside the housing2flows into an internal space of the housing2through the inlets19A. Air inside the housing2flows out of the housing2through the outlets19B.

The casing4accommodates the power transmission7. The casing4includes a first casing4A and a second casing4B. The second casing4B is located in front of the first casing4A. The mode switch ring13is located in front of the second casing4B. The first casing4A is formed from a synthetic resin. The second casing4B is formed from a metal. The second casing4B in the embodiment is formed from aluminum. The casing4is located in front of the motor compartment21. The first casing4A and the second casing4B are cylindrical.

The first casing4A is fixed to the rear end of the second casing4B. The first casing4A has a rear opening covered by a bracket plate4C. The second casing4B has a front opening covered by a stop plate4D. The stop plate4D is fastened to the front end of the second casing4B with screws4E.

The casing4covers a front opening of the motor compartment21. The first casing4A is located inside the motor compartment21. The second casing4B is fastened to the motor compartment21with screws4S.

The battery mount5is located in a lower portion of the battery holder23. The battery mount5is connected to a battery pack20. The battery pack20is attached to the battery mount5in a detachable manner. The battery pack20includes a secondary battery. The battery pack20in the embodiment includes a rechargeable lithium-ion battery. The battery pack20is attached to the battery mount5to power the driver drill1. The motor6is driven by power supplied from the battery pack20. The interface panel15and the controller18operate on power supplied from the battery pack20.

The motor6powers the driver drill1. The motor6is a brushless inner-rotor motor. The motor6is accommodated in the motor compartment21. The motor6includes a cylindrical stator61and a rotor62located inside the stator61. The rotor62includes a rotor shaft63extending in the axial direction.

The power transmission7is located in front of the motor6. The power transmission7is accommodated in the casing4. The power transmission7connects the rotor shaft63and the output unit8together. The power transmission7transmits power generated by the motor6to the output unit8. The power transmission7includes multiple gears.

The power transmission7includes a reducer30and a vibrator40.

The reducer30reduces rotation of the rotor shaft63and rotates the output unit8at a lower rotational speed than the rotor shaft63. The reducer30in the embodiment includes a first planetary gear assembly31, a second planetary gear assembly32, and a third planetary gear assembly33. The second planetary gear assembly32is located in front of the first planetary gear assembly31. The third planetary gear assembly33is located in front of the second planetary gear assembly32.

The vibrator40vibrates the output unit8in the axial direction. The vibrator40includes a first cam41, a second cam42, and a vibration switch ring43.

The output unit8is located frontward from the motor6. The output unit8rotates with a rotational force from the motor6. The output unit8holding a tip tool rotates with a rotational force transmitted from the motor6through the power transmission7. The output unit8includes a spindle81and a chuck82. The spindle81rotates about the rotation axis AX with a rotational force transmitted from the motor6. The chuck82receives the tip tool.

The fan9is located behind the motor6. The fan9generates an airflow for cooling the motor6. The fan9is fixed to at least a part of the rotor62. The fan9is fixed to a rear portion of the rotor shaft63. The fan9rotates together with the rotor shaft63as the rotor shaft63rotates. Thus, air outside the housing2flows into the internal space of the housing2through the inlets19A. Air flowing into the internal space of the housing2flows through the housing2and cools the motor6. The air passing through the housing2flows out of the housing2through the outlets19B.

The trigger lever10is operable to activate the motor6. The trigger lever10is located in an upper portion of the grip22. The trigger lever10has a front end protruding frontward from the front portion of the grip22. The trigger lever10is movable in the front-rear direction. The trigger lever10is operable by the operator. The trigger lever10is operated to move backward to activate the motor6. When the trigger lever10is released from being operated, the motor6is stopped.

The forward-reverse switch lever11is operable to change the rotation direction of the motor6. The forward-reverse switch lever11is located in the upper portion of the grip22. The forward-reverse switch lever11has a left end protruding leftward from a left portion of the grip22. The forward-reverse switch lever11has a right end protruding rightward from a right portion of the grip22. The forward-reverse switch lever11is laterally movable. The forward-reverse switch lever11is operable by the operator. The forward-reverse switch lever11moves leftward to rotate the motor6forward. The forward-reverse switch lever11moves rightward to rotate the motor6reversely. Switching the rotation direction of the motor6switches the rotation direction of the spindle81.

The speed switch lever12changes the speed mode of the reducer30. The speed switch lever12is located in an upper portion of the motor compartment21. The speed switch lever12is movable in the front-rear direction. The speed switch lever12is operable by the operator. The speed mode of the reducer30includes a low-speed mode and a high-speed mode. In the low-speed mode, the output unit8rotates at a low speed. In the high-speed mode, the output unit8rotates at a high speed. The speed switch lever12moves forward to set the reducer30to the low-speed mode. The speed switch lever12moves backward to set the reducer30to the high-speed mode.

The mode switch ring13is operable to change the operation mode of the vibrator40. The mode switch ring13is located in front of the casing4. The mode switch ring13is rotatable. The mode switch ring13is operable by the operator. The operation mode of the vibrator40includes a vibration mode and a non-vibration mode. In the vibration mode, the output unit8vibrates in the axial direction. In the non-vibration mode, the output unit8does not vibrate in the axial direction. The mode switch ring13is placed at a vibration mode position to set the vibrator40to the vibration mode. The mode switch ring13is placed at a non-vibration mode position to set the vibrator40to the non-vibration mode.

The light unit14emits illumination light to illuminate ahead of the driver drill1. The light unit14includes, for example, a light-emitting diode (LED). The light unit14is located in a front left portion of the battery holder23.

The interface panel15is located on the battery holder23. The interface panel15includes an operation unit24and a display25. The interface panel15is a plate. The operation unit24includes an operation button. The display25is, for example, a segment display including multiple segment light emitters, a flat display panel such as a liquid crystal display, or an indicator display including multiple LEDs.

The battery holder23has a panel opening27. The panel opening27is located in an upper surface of the battery holder23and frontward from the grip22. The panel opening27receives at least a part of the interface panel15.

The operation unit24is operable to change the drive mode of the motor6. The operation unit24is operable by the operator. The drive mode of the motor6includes a drill mode and a clutch mode. In the drill mode, the motor6is driven independently of the torque applied to the motor6in driving the motor6. In the clutch mode, the motor6is stopped in response to a torque value applied to the motor6in driving the motor6exceeding a torque threshold.

The dial (first operation member)16is operable to change the drive conditions of the motor6. The dial16is located in a front right portion of the battery holder23. The dial16is rotatable about a dial axis DX. The dial axis DX extends laterally. The dial16is rotatable by 360° or greater. The dial16is operable by the operator. The drive conditions of the motor6include the torque threshold. The dial16is operable to change the torque threshold in the clutch mode set by the operation unit24.

The battery holder23has a dial opening28. The dial opening28is located in the front right portion of the battery holder23. The dial opening28receives at least a part of the dial16.

The hand switch (second operation member)17is operable to change the drive conditions of the motor6. The hand switch17is located upward from the dial16. The hand switch17is located on the grip22or the motor compartment21. The hand switch17in the embodiment is located above the trigger lever10and below the mode switch ring13in the front portion of the grip22. The forward-reverse switch lever11and the hand switch17are at least partially located at the same height.

The hand switch17has a front end protruding frontward from the front portion of the grip22. The hand switch17is movable in the front-rear direction. The hand switch17is operable by the operator. The hand switch17is a push switch. The hand switch17is pushed backward to change the drive conditions of the motor6. As described above, the drive conditions of the motor6include the torque threshold. In the clutch mode, a single push on the hand switch17changes the torque threshold by a predetermined value.

The controller18includes a computer system. The controller18outputs a control command for controlling the motor6. The controller18is at least partially accommodated in a controller case26. The controller18is accommodated in the battery holder23while being held by the controller case26. The controller18includes a circuit board on which multiple electronic components are mounted. Examples of the electronic components mounted on the circuit board include a processor such as a central processing unit (CPU), a nonvolatile memory such as a read-only memory (ROM) or a storage device, a volatile memory such as a random-access memory (RAM), a transistor, a capacitor, and a resistor.

The controller18sets the drive conditions of the motor6in response to an operation on at least one of the dial16or the hand switch17. As described above, the drive conditions of the motor6include the torque threshold. The controller18sets the torque threshold in response to an operation on at least one of the dial16or the hand switch17in the clutch mode.

In the clutch mode, the controller18stops the motor6in response to a torque value applied to the motor6in driving the motor6exceeding the set torque threshold.

The controller18displays the set drive conditions of the motor6on the display25. The controller18displays the set torque threshold on the display25.

Motor and Power Transmission

FIG.5is a partial sectional view of the driver drill1according to the embodiment. As shown inFIG.5, the motor6includes the cylindrical stator61and the rotor62located inside the stator61. The rotor62includes the rotor shaft63extending in the axial direction.

The stator61includes a stator core61A, a front insulator61B, a rear insulator61C, multiple coils61D, a sensor circuit board61E, fusing terminals61F, and short-circuiting members61G. The stator core61A includes multiple steel plates stacked on one another. The front insulator61B is located in front of the stator core61A. The rear insulator61C is located behind the stator core61A. The coils61D are wound around the stator core61A with the front insulator61B and the rear insulator61C between them. The sensor circuit board61E is attached to the front insulator61B. The fusing terminals61F are connected to the coils61D. The short-circuiting members61G are supported by the front insulator61B. The sensor circuit board61E includes multiple rotation detectors to detect rotation of the rotor62. The short-circuiting members61G connect the multiple coils61D with the fusing terminals61F. The short-circuiting members61G are connected to the controller18with lead wires.

The rotor62rotates about the rotation axis AX. The rotor62includes the rotor shaft63, a rotor core62A, and multiple permanent magnets62B. The rotor core62A surrounds the rotor shaft63. The multiple permanent magnets62B are held by the rotor core62A. The rotor core62A is cylindrical. The rotor core62A includes multiple steel plates stacked on one another. The rotor core62A has multiple through-holes extending in the axial direction and aligned circumferentially. The permanent magnets62B are placed in the respective through-holes in the rotor core62A.

The rotation detectors in the sensor circuit board61E detect the magnetic fields of the permanent magnets62B to detect rotation of the rotor62. The controller18provides a drive current to the coils61D based on the detection data from the rotation detectors.

The rotor shaft63rotates about the rotation axis AX. The rotation axis AX of the rotor shaft63is aligned with the rotation axis of the output unit8. The rotor shaft63has a front portion rotatably supported by a bearing64. The rotor shaft63has a rear portion rotatably supported by a bearing65. The bearing64is held by the bracket plate4C located in front of the stator61. The bearing65is held by the rear cover3. The rotor shaft63has its front end located frontward from the bearing64in an internal space of the casing4.

A pinion gear31S is located at the front end of the rotor shaft63. The rotor shaft63is connected to the first planetary gear assembly31in the reducer30with the pinion gear31S.

The first planetary gear assembly31includes multiple planetary gears31P, a first carrier31C, and an internal gear31R. The planetary gears31P surround the pinion gear31S. The first carrier31C supports the planetary gears31P. The internal gear31R surrounds the planetary gears31P. The first carrier31C includes a gear on its outer periphery.

The second planetary gear assembly32includes a sun gear32S, multiple planetary gears32P, a second carrier32C, and an internal gear32R. The planetary gears32P surround the sun gear32S. The second carrier32C supports the planetary gears32P. The internal gear32R surrounds the planetary gears32P. The sun gear32S is located in front of the first carrier31C. The sun gear32S has a smaller diameter than the first carrier31C. The sun gear32S is integral with the first carrier31C. The sun gear32S and the first carrier31C rotate together.

The third planetary gear assembly33includes a sun gear33S, multiple planetary gears33P, a third carrier33C, and an internal gear33R. The planetary gears33P surround the sun gear33S. The third carrier33C supports the planetary gears33P. The internal gear33R surrounds the planetary gears33P. The sun gear33S is located in front of the second carrier32C.

The reducer30includes a speed switch ring34and a connection ring35. The speed switch ring34is connected to the speed switch lever12. The connection ring35is located in front of the speed switch ring34. The connection ring35is fixed to the inner surface of the first casing4A. The connection ring35includes a gear on its inner periphery. The speed switch ring34includes a protrusion34T protruding upward. Coil springs36are located in front of and behind the protrusion34T. The speed switch ring34is connected to the speed switch lever12with the coil springs36in between.

The speed switch ring34switches between the low-speed mode and the high-speed mode. The speed switch ring34is connected to the internal gear32R. The speed switch lever12is connected to the internal gear32R with the speed switch ring34. The speed switch lever12is movable together with the speed switch ring34and the internal gear32R. The operator operates the speed switch lever12to move the speed switch ring34in the front-rear direction in the first casing4A. The speed switch ring34moves between a low-speed mode position and a high-speed mode position in the front-rear direction with the internal gear32R meshing with the planetary gears32P. The high-speed mode position is located rearward from the low-speed mode position. The speed switch ring34thus switches between the low-speed mode and the high-speed mode. The speed switch lever12is operable to switch between the low-speed mode and the high-speed mode.

The internal gear32R at the low-speed mode position is in contact with the connection ring35. This restricts rotation of the internal gear32R. The internal gear32R at the high-speed mode position is apart from the connection ring35. This allows rotation of the internal gear32R.

The internal gear32R at the low-speed mode position meshes with the planetary gears32P. The internal gear32R at the high-speed mode position meshes with both the planetary gears32P and the first carrier31C.

When the rotor shaft63rotates as driven by the motor6with the internal gear32R at the low-speed mode position, the pinion gear31S rotates, and the planetary gears31P revolve about the pinion gear31S. The first carrier31C and the sun gear32S then rotate at a lower rotational speed than the rotor shaft63. The planetary gears32P then revolve about the sun gear32S. The second carrier32C and the sun gear33S then rotate at a lower rotational speed than the first carrier31C. When the motor6is driven with the internal gear32R at the low-speed mode position, both the first planetary gear assembly31and the second planetary gear assembly32operate for rotation reduction, causing the second carrier32C and the sun gear33S to rotate in the low-speed mode.

When the rotor shaft63rotates as driven by the motor6with the internal gear32R at the high-speed mode position, the pinion gear31S rotates, and the planetary gears31P revolve about the pinion gear31S. The first carrier31C and the sun gear32S then rotate at a lower rotational speed than the rotor shaft63. The internal gear32R at the high-speed mode position meshes with both the planetary gears32P and the first carrier31C. Thus, the internal gear32R rotates together with the first carrier31C.

As the internal gear32R rotates, the planetary gears32P revolve at the same revolution speed as the rotational speed of the internal gear32R. The second carrier32C and the sun gear33S then rotate at the same rotational speed as the rotational speed of the first carrier31C. When the motor6is driven with the internal gear32R at the high-speed mode position, the first planetary gear assembly31operates for rotation reduction without the second planetary gear assembly32operating for rotation reduction, thus causing the second carrier32C and the sun gear33S to rotate in the high-speed mode.

As the second carrier32C and the sun gear33S rotate, the planetary gears33P revolve about the sun gear33S. This causes the third carrier33C to rotate.

The spindle81is connected to the third carrier33C with a lock cam85. The spindle81is spline-coupled to the lock cam85. The lock cam85is rotatably supported by a lock ring86. The lock ring86is located inside the second casing4B. The lock ring86is fixed to the second casing4B. As the third carrier33C rotates, the spindle81rotates.

The spindle81is rotatably supported by a bearing83and a bearing84. The spindle81, supported by the bearings83and84, is movable in the front-rear direction.

The spindle81includes a flange81F. A coil spring87is located between the flange81F and the bearing83. The coil spring87generates an elastic force for moving the spindle81forward.

The chuck82can hold the tip tool. The chuck82is connected to the front of the spindle81. The chuck82rotates as the spindle81rotates. The chuck82holding the tip tool rotates.

The first cam41and the second cam42in the vibrator40are located inside the second casing4B. The first cam41and the second cam42are located between the bearings83and84in the front-rear direction.

The first cam41is annular. The first cam41surrounds the spindle81. The first cam41is fixed to the spindle81. The first cam41rotates together with the spindle81. The first cam41includes cam teeth on its rear surface. The first cam41is supported by a stop ring44. The stop ring44surrounds the spindle81. The stop ring44is located between the first cam41and the bearing83in the front-rear direction. The elastic force from the coil spring87causes the stop ring44to come in contact with a rear surface of the bearing83.

The second cam42is annular. The second cam42is located behind the first cam41. The second cam42surrounds the spindle81. The second cam42is rotatable relative to the spindle81. The second cam42includes cam teeth on its front surface. The cam teeth on the front surface of the second cam42mesh with the cam teeth on the rear surface of the first cam41. The second cam42includes a tab on its rear surface.

A support ring45is located between the second cam42and the bearing84in the front-rear direction. The support ring45is located inside the second casing4B. The support ring45is fixed to the second casing4B. The support ring45includes multiple steel balls46on its front surface. A washer47is located between the steel balls46and the second cam42. The second cam42is rotatable while being restricted from moving back and forth in a space defined by a small diameter portion402and the washer47.

The vibration switch ring43switches between the vibration mode and the non-vibration mode. The mode switch ring13is connected to the vibration switch ring43with a cam ring48. The mode switch ring13is rotatable together with the cam ring48. The vibration switch ring43is movable in the front-rear direction. The vibration switch ring43includes a projection43T. The projection43T is placed into a guide hole in the second casing4B. The vibration switch ring43is movable in the front-rear direction while being guided by the guide hole in the second casing4B. The projection43T restricts rotation of the vibration switch ring43. The operator operates the mode switch ring13to move the vibration switch ring43in the front-rear direction. The vibration switch ring43moves in the front-rear direction between an advanced position and a retracted position to switch between the vibration mode and the non-vibration mode. The retracted position is located rearward from the advanced position. The mode switch ring13is operable to switch between the vibration mode and the non-vibration mode.

The vibration mode includes a restricted state of rotation of the second cam42. The non-vibration mode includes a rotatable state of the second cam42. When the vibration switch ring43moves to the advanced position, the second cam42is restricted from rotating. When the vibration switch ring43moves to the retracted position, the second cam42becomes rotatable.

In the vibration mode, the vibration switch ring43at the advanced position is at least partially in contact with the second cam42. This restricts rotation of the second cam42. When the motor6is driven in this state, the first cam41fixed to the spindle81rotates in contact with the cam teeth on the second cam42. The spindle81thus rotates while vibrating in the front-rear direction.

In the non-vibration mode, the vibration switch ring43at the retracted position is apart from the second cam42. This allows rotation of the second cam42. When the motor6is driven in this state, the second cam42rotates together with the first cam41and the spindle81. The spindle81thus rotates without vibrating in the front-rear direction.

The vibration switch ring43surrounds the first cam41and the second cam42. The vibration switch ring43has an opposing portion43S facing the rear surface of the second cam42. The opposing portion43S protrudes radially inward from a rear portion of the vibration switch ring43.

When the mode switch ring13is operated to move the vibration switch ring43to the advanced position, the tab on the rear surface of the second cam42is in contact with the opposing portion43S of the vibration switch ring43. This restricts rotation of the second cam42. The vibrator40is thus switched to the vibration mode.

When the mode switch ring13is operated to move the vibration switch ring43to the retracted position, the opposing portion43S of the vibration switch ring43is apart from the second cam42. This allows rotation of the second cam42. The vibrator40is thus switched to the non-vibration mode.

FIG.6is a front view of the dial16in the embodiment.FIG.7is a sectional view of the dial16and the light unit14in the embodiment. As shown inFIGS.1to4,6, and7, the dial16is located in the front right portion of the battery holder23. The light unit14is located in the front left portion of the battery holder23.

The battery holder23has the dial opening28receiving at least a part of the dial16. The dial opening28is included in the front right portion of the battery holder23.

The dial16is located in front of the controller18. The dial16is cylindrical. The dial16is operable by the operator. The dial16has a surface with multiple protrusions16T. The protrusions16T prevent slipping. The dial16includes a front portion and an upper portion located outward from the surface of the battery holder23.

The dial16rotates about the dial axis DX extending laterally. As described above, the motor6has the rotation axis AX extending in the front-rear direction. In the embodiment, the rotation axis AX of the motor6and an axis parallel to the dial axis DX are orthogonal to each other.

The driver drill1includes a rod161, permanent magnets162, a cam163, and a coil spring164. The rod161is located inside the dial16. The permanent magnets162are supported by the rod161. The cam163is supported by the rod161. The coil spring164surrounds the rod161.

The rod161is located in front of the controller18, and is supported by at least a part of the battery holder23. The rod161has a left end and a right end each supported by the battery holder23.

The dial16surrounds the rod161. The dial16is rotatably supported by the rod161. The dial16is rotatable by 360° or greater about the dial axis DX in both the forward direction and the reverse direction.

The dial16has a recess16L on its left surface. The recess16L receives a cam projection16A. The dial16has a recess16R on its right surface. The recess16R receives a projection16B. The left and right surfaces of the dial16each include an annular ridge16C.

The permanent magnets162rotate together with the dial16. The permanent magnets162and the dial16are located at different positions in the direction parallel to the dial axis DX. The permanent magnets162in the embodiment are located on the right of the dial16. The permanent magnets162are arranged cylindrically. At least a part of the rod161is located inward from the permanent magnets162. The permanent magnets162surround the rod161. The permanent magnets162are fixed to the dial16with, for example, an adhesive.

The cam163and the dial16are located at different positions in the direction parallel to the dial axis DX. The cam163in the embodiment is located on the left of the dial16. The cam163is cylindrical. The cam163receives at least a part of the rod161. The cam163surrounds the rod161. The cam163is laterally movable with respect to the rod161. The cam163includes a cam projection163A on its right surface. The cam163includes two protrusions163T on its outer surface.

The coil spring164and the dial16are located at different positions in the direction parallel to the dial axis DX. The coil spring164in the embodiment is located on the left of the dial16. The coil spring164receives at least a part of the rod161. The coil spring164surrounds the rod161. The coil spring164is at least partially located inside the cam163.

The battery holder23has a central recess165, a left recess166, and a right recess167. The central recess165receives the dial16. The left recess166receives the cam163. The right recess167receives the permanent magnets162.

The left recess166has an inner surface at least partially holding the left end of the rod161. The right recess167has an inner surface at least partially holding the right end of the rod161.

The left recess166has a groove168inside receiving the protrusions163T on the cam163. This restricts rotation of the cam163.

The cam163includes a right portion received in the recess16L on the dial16. The coil spring164includes a right portion received in the cam163. The coil spring164includes a left portion supported on at least a part of the inner surface of the left recess166. This restricts rotation of the coil spring164. The coil spring164generates an elastic force for moving the cam163rightward.

When the operator operates the dial16, the dial16rotates with respect to the cam163with the cam163pressed against the dial16by the coil spring164. The dial16rotates with the cam projection16A and the cam projection163A in contact with each other. Thus, the dial16clicks while rotating.

Each permanent magnet162includes a left portion received in the recess16R on the dial16. The left portion of the permanent magnet162has a notch that receives the projection16B when the left portion of the permanent magnet162is placed into the recess16R on the dial16. This restricts rotation of the dial16and the permanent magnets162with respect to each other. The permanent magnets162rotate together with the dial16.

The left and right surfaces of the dial16each include the annular ridge16C. The battery holder23includes a cover169covering the ridges16C. The ridges16C and the cover169prevent foreign objects from entering an internal space of the battery holder23through a space between the housing2and the dial16.

Controller

FIG.8is a block diagram of the driver drill1according to the embodiment. As shown inFIG.8, the driver drill1includes the sensor circuit board61E, the trigger lever10, the forward-reverse switch lever11, the speed switch lever12, the mode switch ring13, the dial16, the hand switch17, the operation unit24, a trigger signal generator51, a forward-reverse sensor52, a speed sensor53, a mode sensor54, a dial sensor55, an acceleration sensor56, the controller18, the motor6, and the display25.

The controller18calculates a torque value applied to the motor6. The controller18calculates a torque value applied to the motor6based on a current value supplied to the coils61D and the rotational speed of the rotor62detected by a rotation detector in the sensor circuit board61E.

As shown inFIG.4, the trigger signal generator51is located in the grip22. The trigger signal generator51generates a trigger signal based on the amount of operation on the trigger lever10. The trigger signal generated in the trigger signal generator51is output to the controller18. The controller18drives the motor6in response to the trigger signal from the trigger signal generator51.

The forward-reverse sensor52detects the operational state of the forward-reverse switch lever11. The forward-reverse sensor52detects the position of the forward-reverse switch lever11that is laterally movable.

The forward-reverse sensor52outputs the detection data to the controller18. The controller18detects the position of the speed switch lever12based on the detection data from the forward-reverse sensor52. The controller18uses the detection data from the forward-reverse sensor52to determine whether the rotation direction of the motor6is set to the forward direction or to the reverse direction.

The speed sensor53detects the operational state of the speed switch lever12. As shown inFIG.5, the speed switch ring34includes a permanent magnet34M. The speed sensor53is located below the speed switch ring34. The speed sensor53includes a magnetic sensor, such as a Hall device. In response to an operation on the speed switch lever12, the permanent magnet34M moves in the front-rear direction along with the speed switch lever12and the speed switch ring34. The speed sensor53detects a change in the magnetic field caused by the moving permanent magnet34M.

The speed sensor53outputs the detection data to the controller18. The controller18detects the position of the speed switch lever12based on the detection data from the speed sensor53. The controller18uses the detection data from the speed sensor53to determine whether the reducer30is set to the high-speed mode or to the low-speed mode.

The mode sensor54detects the operational state of the mode switch ring13. As shown inFIG.5, a mode detection ring49is located inside and rotatable together with the mode switch ring13. The mode detection ring49includes a permanent magnet49M. The mode sensor54is located below the mode detection ring49. The mode sensor54includes a magnetic sensor, such as a Hall device. In response to an operation on the mode switch ring13, the permanent magnet49M rotates together with the mode switch ring13and the mode detection ring49. The mode sensor54detects a change in the magnetic field caused by the rotating permanent magnet49M.

The mode sensor54outputs the detection data to the controller18. The controller18detects the position of the mode switch ring13in the rotation direction based on the detection data from the mode sensor54. The controller18uses the detection data from the mode sensor54to determine whether the vibrator40is set to the vibration mode or to the non-vibration mode.

The dial sensor55detects the operational state of the dial16. The dial sensor55includes a magnetic sensor, such as a Hall device. The dial sensor55detects the permanent magnets162. The dial sensor55is located behind the permanent magnets162. In response to an operation on the dial16, the permanent magnets162rotate together with the dial16. The dial sensor55detects a change in the magnetic field caused by the rotating permanent magnets162.

The permanent magnets162are arranged to each have an N pole and an S pole that alternate in the circumferential direction of the dial axis DX. The operator rotates the dial16about the dial axis DX in the forward direction or in the reverse direction. The permanent magnets162rotate together with the dial16.

When the dial16is rotated and the S pole faces the dial sensor55, the magnetic lines of force between the permanent magnets162and the dial sensor55are directed from the dial sensor55to the permanent magnets162. When the dial16is rotated and the N pole and the S pole located above the N pole both face the dial sensor55, the magnetic lines of force between the permanent magnets162and the dial sensor55are directed from the N pole to the S pole. When the dial16is rotated and the N pole faces the dial sensor55, the magnetic lines of force between the permanent magnets162and the dial sensor55are directed from the permanent magnets162to the dial sensor55. When the dial16is rotated and the S pole and the N pole located above the S pole both face the dial sensor55, the magnetic lines of force between the permanent magnets162and the dial sensor55are directed from the N pole to the S pole.

Thus, the rotation angle of the dial16changes the direction of magnetic lines of force between the permanent magnets162and the dial sensor55. In other words, the rotation angle of the dial16changes the magnetic field between the permanent magnets162and the dial sensor55. The rotation direction of the dial16changes the magnetic field between the permanent magnets162and the dial sensor55. The dial sensor55detects a change in the magnetic field to detect the rotation direction and the rotation angle of the dial16.

The dial sensor55outputs the detection data to the controller18. The controller18determines the rotation direction and the rotational speed of the dial16based on the detection data from the dial sensor55. The detection data from the dial sensor55includes a clutch threshold in the clutch mode. In the clutch mode, the controller18sets a torque threshold based on the detection data from the dial sensor55.

In response to an operation by the operator, the hand switch17generates operation data. The operation data generated by the hand switch17is transmitted to the controller18. The operation data from the hand switch17includes the clutch threshold in the clutch mode. In the clutch mode, the controller18sets the torque threshold based on the operation data from the hand switch17.

In response to an operation by the operator, the operation unit24generates operation data. The operation data generated by the operation unit24is transmitted to the controller18. The operation data from the operation unit24includes the drill mode or the clutch mode. The controller18sets the drill mode or the clutch mode based on the operation data from the operation unit24.

Operation of Driver Drill

FIG.9is a diagram showing an example use of the driver drill1according to the embodiment. InFIG.9, the driver drill1with a tip tool70attached to the output unit8is in a screwing operation.

An example screwing operation with the driver drill1in the clutch mode will be described below. The operator operates the mode switch ring13to set the vibrator40to the non-vibration mode, and selects the clutch mode by operating the operation unit24.

In the clutch mode, the motor6stops in response to a torque value applied to the motor6in driving the motor6exceeding a torque threshold. After selecting the clutch mode, the operator operates at least one of the dial16or the hand switch17to set a torque threshold.

The dial16and the hand switch17are operable in different directions. The dial16is operable in the rotation direction about the dial axis DX. The hand switch17is operable in the front-rear direction. As the dial16and the hand switch17are operable in different directions, the operator can use the hand switch17to change the torque threshold, for example, in a work situation in which the dial16is difficult to operate. In a work situation in which the hand switch17is difficult to operate, for example, the operator can use the dial16to change the torque threshold.

The torque threshold may be set finely. For example, the controller18may set the torque threshold from 40 preset values.

When the torque threshold is set with the dial16, for example, rotating the dial16in the forward direction by 45° increases the torque threshold to the next value. Rotating the dial16in the reverse direction by 45° decreases the torque threshold to the previous value. The dial16in the embodiment is rotatable by 360° or greater about the dial axis DX in both the forward direction and the reverse direction. Thus, the operator can set the torque threshold precisely from the 40 preset values by rotating the dial16in the forward direction or the reverse direction by 45°.

The rotation angle of the dial16for changing the torque threshold to the next value is not limited to 45°, and may be less than 45° or greater than 45°.

When the hand switch17is used to set the torque threshold, for example, a single push on the hand switch17in a first operational state in which the forward-reverse switch lever11is moved to the left position increases the torque threshold to the next value. Multiple pushes on the hand switch17in the first operational state increase the torque threshold by multiple preset values.

In a second operational state in which the forward-reverse switch lever11is moved to the right position, a single push on the hand switch17decreases the torque threshold to the previous value. Multiple pushes on the hand switch17in the second operational state decrease the torque threshold by multiple preset values.

The controller18uses the detection data from the forward-reverse sensor52to determine whether the forward-reverse switch lever11is in the first operational state or in the second operational state. The controller18thus can increase or decrease the torque threshold based on the detection data from the forward-reverse sensor52and the operation data from the hand switch17.

In the first operational state, for example, a single push on the hand switch17may increase the torque threshold by two preset values or by any multiple values. In the second operational state, a single push on the hand switch17may decrease the torque threshold by two preset values or by any multiple values.

In some embodiments, pushing the hand switch17in the first operational state may decrease the torque threshold. Pushing the hand switch17in the second operational state may increase the torque threshold.

The number of preset values for the torque threshold is not limited to 40, and may be less than or more than 40.

In the clutch mode, the operator sets the torque threshold by operating the dial16, for example, before starting the screwing operation.

The controller18displays the torque threshold set with the dial16on the display25.

After setting the torque threshold, the operator operates the trigger lever10to activate the motor6. The controller18controls the rotational speed of the motor6based on the amount of operation on the trigger lever10. The controller18uses the detection data from the rotation detector in the sensor circuit board61E to control the motor6to rotate the motor6at the target rotational speed determined based on the amount of operation on the trigger lever10.

The controller18calculates a torque value applied to the motor6. The controller18calculates a torque value applied to the motor6based on a current value supplied to the coils61D and the rotational speed of the rotor62detected by the rotation detector in the sensor circuit board61E.

The controller18stops the motor6in response to the calculated torque value applied to the motor6in driving the motor6exceeding the set torque threshold.

As shown inFIG.9, when the motor6stops before a screw is fully screwed into a workpiece, the operator can operate the hand switch17to increase the torque threshold. The operator holding the grip22of the driver drill1with the right hand can operate the hand switch17with the right index finger or another finger, while remaining in a working posture for using the driver drill1. In other words, the operator can adjust the torque threshold with one hand, while remaining in a working posture for using the driver drill1.

The hand switch17included in a vibration driver drill in particular operates effectively. For example, clutch setting of the driver drill1may be changed electrically by a clutch ring attached to the distal end of the second casing4B. The clutch setting is electrically changed by a ring component. In the vibration driver drill, the ring component may break during a vibration operation.

In the present embodiment, a button, or the hand switch17, is used to change the clutch setting and is less likely to break. More specifically, unlike unintended shakes in screwing or impact actions with an impact driver, the vibration driver drill vibrates many times in short cycles. The component used for electrically changing the clutch setting in the present embodiment is less likely to break when in use.

As described above, the driver drill1according to the embodiment includes the motor6, the output unit8located frontward from the motor6and rotatable with a rotational force from the motor6, the trigger lever10operable to activate the motor6, the forward-reverse switch lever11operable to change the rotation direction of the motor6, the dial16as the first operation member operable to change the drive conditions of the motor6, the hand switch17as the second operation member located upward from the dial16and operable to change the drive conditions of the motor6, and the controller18that sets the drive conditions of the motor6in response to an operation on at least one of the dial16or the hand switch17.

The above structure includes the hand switch17in addition to the dial16. The hand switch17is located upward from the dial16. The operator can change the drive conditions of the motor6smoothly by operating the hand switch17, while remaining in a working posture for using the driver drill1.

The driver drill1according to the embodiment includes the housing2including the motor compartment21accommodating the motor6, the grip22extending downward from the motor compartment21, and the battery holder23below the grip22. The dial16is located on the battery holder23, and the hand switch17is located on the grip22or the motor compartment21.

Thus, the operator holding the grip22with a hand can change the drive conditions of the motor6smoothly by operating the hand switch17, while remaining in a working posture for using the driver drill1.

The trigger lever10in the embodiment is located in the front portion of the grip22. The hand switch17is located above the trigger lever10.

Thus, the operator holding the grip22with the right hand can, for example, operate the hand switch17with the right index finger or another finger, while remaining in a working posture for using the driver drill1. In other words, the operator can change the drive conditions of the motor6with one hand, while remaining in a working posture for using the driver drill1.

The controller18in the embodiment stops the motor6in response to a torque value applied to the motor6in driving the motor6exceeding a torque threshold. The drive conditions include the torque threshold.

An operation on the hand switch17while the driver drill1is set to the clutch mode changes the torque threshold.

The hand switch17in the embodiment includes a push switch. A single push on the hand switch17changes the torque threshold by a predetermined value.

The operator can change the torque threshold by the predetermined value by pushing the hand switch17, or the push switch. A single push changes the torque threshold to the next value, for example, as the predetermined value.

In the embodiment, pushing the hand switch17with the forward-reverse switch lever11in the first operational state increases the torque threshold, and pushing the hand switch17with the forward-reverse switch lever11in the second operational state decreases the torque threshold.

The operational states of the forward-reverse switch lever11and the hand switch17are combined to increase or decrease the torque threshold.

The forward-reverse switch lever11and the hand switch17in the embodiment are at least partially located at the same height.

Thus, the operator can operate the forward-reverse switch lever11and the hand switch17, for example, by one hand.

In the embodiment, the dial16and the hand switch17are operable in different directions.

Thus, the operator can control the drive conditions of the motor6by operating the operation member, the dial16or the hand switch17, that is easier to use in a work situation. The operator can use the hand switch17to change the torque threshold, for example, in a work situation in which the dial16is difficult to operate. The operator can use the dial16to change the torque threshold, for example, in a work situation in which the hand switch17is difficult to operate.

The dial16in the embodiment is rotatable by 360° or greater.

Thus, the operator can easily change the drive conditions of the motor6.

The driver drill1according to the embodiment includes the display25. The controller18causes the display25to display the drive conditions of the motor6.

Thus, the operator can identify the drive conditions of the motor6by viewing the display25.

Other Embodiments

As shown inFIG.8, the driver drill1includes the acceleration sensor56. The acceleration sensor56detects the acceleration acting on, for example, the housing2. The controller18stops the motor6in response to the acceleration sensor56detecting a value greater than an acceleration threshold. The drive conditions include the acceleration threshold. The acceleration threshold may be changed with an operation on the hand switch17.

In the screwing operation with the driver drill1, the driver drill1may receive an excessive reaction force and may move greatly against a force from the operator. The acceleration sensor56detects the movement of the driver drill1. In response to a determination that the acceleration acting on the driver drill1exceeds the acceleration threshold based on the detection data from the acceleration sensor56, the controller18stops the motor6.

The operator can use the hand switch17to adjust the acceleration threshold in accordance with, for example, a work situation.

FIG.10is a rear perspective view of a driver drill1B according to a modification. A hand switch17B is located upward from the dial16. In the example shown inFIG.10, the hand switch17B is located on the rear surface of the rear cover3.

In the example shown inFIG.10as well, the operator holding the grip22with a hand can change the drive conditions of the motor6smoothly by operating the hand switch17B, while remaining in a working posture for using the driver drill1B. The operator holding the grip22with the right hand can, for example, operate the hand switch17B with the right thumb or in another manner, while remaining in a working posture for using the driver drill1B.

As described above, the driver drill1B, which is a vibration driver drill in the example inFIG.10, includes the motor6, the output unit8located frontward from the motor6and rotatable with a rotational force from the motor6, the vibrator40between the motor6and the output unit8to switch the output unit8between vibrating in the front-rear direction and not vibrating in the front-rear direction, the trigger lever10operable to activate the motor6, the forward-reverse switch lever11operable to change the rotation direction of the motor6, the motor compartment21and the rear cover3as a motor housing accommodating the motor6, the grip22as a grip housing extending downward from the motor housing, the hand switch17B as an operation button on the rear cover3, which is a part of the motor housing, and the controller18that sets the drive conditions of the motor6in response to an operation on the operation button. The hand switch17B is operable to change the drive conditions of the motor6.

In the above structure, the rear cover3that is a part of the motor housing includes the hand switch17B that is the operation button. The operator can change the drive conditions of the motor6smoothly by operating the operation button, while remaining in a working posture for using the driver drill1B.

FIG.11is a graph describing the drive conditions of the motor6in the modification. The drive conditions of the motor6include the torque threshold in the embodiment described above. The drive conditions of the motor6may include the behavior of the motor6or the time for the rotational speed of the motor6to reach a predetermined value after the trigger lever10is operated. The drive conditions of the motor6may include the behavior of the motor6or the time for the motor6to stop after the torque value applied to the motor6exceeds the torque threshold.

In the graph inFIG.11, the horizontal axis indicates the time elapsed after the trigger lever10is operated, and the vertical axis indicates the rotational speed of the motor6. The trigger lever10is operated at the time point t0. The rotational speed of the motor6increases to a predetermined value based on the amount of operation on the trigger lever10. At the time point t1, the rotational speed of the motor6reaches the predetermined value. At the time point t2, the torque value applied to the motor6exceeds the torque threshold, triggering an operation to stop the motor6. At the time point t3, the motor6stops.

The hand switch17(17B) may be operated to change the time T1for the motor6to reach the predetermined rotational speed after the trigger lever10is operated. The hand switch17(17B) may be operated to change the time T2for the motor6to stop after the torque value applied to the motor6exceeds the torque threshold. The time T1ranges from the time point t0to the time point t1. The time T2ranges from the time point t2to the time point t3.

The hand switch17(17B) may be operated to change the behavior of the motor6for a period for which the rotational speed of the motor6reaches the predetermined value after the trigger lever10is operated. The hand switch17(17B) may be operated to change the behavior of the motor6for a period for which the motor6stops after the torque value applied to the motor6exceeds the torque threshold. In other words, the behavior of the motor6within the time T1may be changed, and the behavior of the motor6within the time T2may be changed. The behavior of the motor6within the time T1is, for example, the rate of increase in the rotational speed of the motor6. The behavior of the motor6within the time T2is, for example, the rate of decrease in the rotational speed of the motor6.

The above structure allows the operator to operate the hand switch17(17B) to adjust the drive conditions of the motor6, for example, as intended by the operator.

In the above embodiments, the driver drill1(1B) is powered by the battery pack20attached to the battery mount5. The driver drill1(1B) may use utility power (alternating-current power supply).

REFERENCE SIGNS LIST