US-12617066-B2 - Electric work machine and driver drill

Abstract

An electric work machine avoids use of more lead wires. The electric work machine includes an operation unit operable in an operation mode of at least three operation modes, an operable member movable to switch the operation mode, a plurality of mode sensors located in a direction of movement of the operable member to detect the operable member and being equal in number to or fewer than the at least three operation modes, a mode sensor board on which the plurality of mode sensors are mounted and including an output terminal connected to the plurality of mode sensors, and a controller board connected to the output terminal with an output lead wire to determine the operation mode based on an output signal output from the output terminal.

Inventors

• Kisho Sekido

Assignees

• MAKITA CORPORATION

Dates

Publication Date

20260505

Application Date

20230109

Priority Date

20220228

Claims (18)

1. 1 . A driver drill, comprising: a motor; an output unit driven by the motor; a vibrator configured to vibrate the output unit in an axial direction; a mode switch ring operable to change operation modes of the vibrator, the operation modes including a vibration mode and a non-vibration mode; a reducer operable in a speed mode of at least three speed modes including a high-speed mode, a medium-speed mode, and a low-speed mode; a speed switch lever movable to switch the speed mode of the reducer; a plurality of mode sensors located in a direction of movement of the speed switch lever to detect the speed switch lever, the plurality of mode sensors being equal in number to or fewer than the at least three speed modes; a mode sensor board on which the plurality of mode sensors are mounted, the mode sensor board including an output terminal connected to the plurality of mode sensors; an operation unit configured to change a drive mode of the motor between a drill mode in which the motor is driven independently of a torque applied to the motor and a clutch mode in which the motor is stopped in response to torque applied to the motor exceeding a torque threshold; a dial configured to change the torque threshold in the clutch mode; and a controller board connected to the output terminal with an output lead wire to determine the speed mode based on an output signal output from the output terminal, the controller board configured to stop the motor in response to torque applied to the motor exceeding the torque threshold in the clutch mode based on detection signal from the mode sensors, wherein the torque thresholds are set to different values for an input value of the torque threshold in the high-speed mode, in the medium-speed mode, and the low-speed mode.
2. 2 . The driver drill according to claim 1 , wherein the plurality of mode sensors are fewer than the at least three speed modes by one.
3. 3 . The driver drill according to claim 1 , wherein each of a plurality of the output terminals is connected to a corresponding mode sensor of the plurality of mode sensors.
4. 4 . The driver drill according to claim 3 , wherein the mode sensor board includes an input terminal connected to the plurality of mode sensors, and the plurality of mode sensors receive a voltage applied through the input terminal.
5. 5 . The driver drill according to claim 4 , wherein the plurality of mode sensors are connected in parallel with one another, and each of the plurality of mode sensors is connected to the input terminal with a power line.
6. 6 . The driver drill according to claim 5 , wherein the mode sensor board includes the input terminal being a single input terminal.
7. 7 . The driver drill according to claim 4 , wherein the speed switch lever holds a permanent magnet, each of the plurality of mode sensors includes a Hall sensor configured to detect the permanent magnet, and each of the plurality of mode sensors includes a power port to which a current is supplied, a first ground port connected to the input terminal with a resistor in between, and a second ground port connected to a ground.
8. 8 . The driver drill according to claim 7 , wherein the plurality of mode sensors include a first mode sensor and a second mode sensor, the output terminal includes a first output terminal connected to the first mode sensor, and a second output terminal connected to the second mode sensor, the resistor includes a first resistor connected to the first mode sensor, and a second resistor connected to the second mode sensor, with the speed switch lever at a first position to switch the speed mode to a first speed mode, the first output terminal outputs an output signal at a first level, and the second output terminal outputs an output signal at a second level, with the speed switch lever at a second position to switch the speed mode to a second speed mode, the first output terminal outputs an output signal at the second level, and the second output terminal outputs an output signal at the second level, and with the speed switch lever at a third position to switch the speed mode to a third speed mode, the first output terminal outputs an output signal at the second level, and the second output terminal outputs an output signal at the first level.
9. 9 . The driver drill according to claim 1 , wherein the plurality of mode sensors are connected in parallel with one another, and each of the plurality of mode sensors is connected to the output terminal with a signal line.
10. 10 . A driver drill, comprising: a motor; an output unit driven by the motor; a vibrator configured to vibrate the output unit in an axial direction; a mode switch ring operable to change operation modes of the vibrator, the operation modes including a vibration mode and a non-vibration mode; a reducer operable in a speed mode of a plurality of speed modes including a high-speed mode, a medium-speed mode, and a low-speed mode; a speed switch lever movable to switch the speed mode of the reducer; a plurality of mode sensors located in a direction of movement of the speed switch lever to detect the speed switch lever, the plurality of mode sensors being connected in parallel with one another; a mode sensor board on which the plurality of mode sensors are mounted, the mode sensor board including an output terminal connected to the plurality of mode sensors; an operation unit configured to change a drive mode of the motor between a drill mode in which the motor is driven independently of a torque applied to the motor and a clutch mode in which the motor is stopped in response to torque applied to the motor exceeding a torque threshold; a dial configured to change the torque threshold in the clutch mode; and a controller board connected to the output terminal with an output lead wire to determine the speed mode based on an output signal output from the output terminal, the controller board configured to stop the motor in response to torque applied to the motor exceeding the torque threshold in the clutch mode based on detection signal from the mode sensors, wherein each of the plurality of mode sensors is connected to the output terminal with a signal line, and the torque thresholds are set to different values for an input value of the torque threshold in the high-speed mode, in the medium-speed mode, and the low-speed mode.
11. 11 . The driver drill according to claim 9 , wherein the mode sensor board includes the output terminal being a single output terminal.
12. 12 . The driver drill according to claim 9 , wherein the mode sensor board includes an input terminal connected to the plurality of mode sensors, and the plurality of mode sensors receive a voltage applied through the input terminal.
13. 13 . The driver drill according to claim 12 , wherein each of the plurality of mode sensors is connected to the input terminal with a power line.
14. 14 . The driver drill according to claim 13 , wherein the mode sensor board includes the input terminal being a single input terminal.
15. 15 . The driver drill according to claim 12 , wherein the speed switch lever holds a permanent magnet, each of the plurality of mode sensors includes a Hall sensor configured to detect the permanent magnet, and each of the plurality of mode sensors includes a power port to which a current is supplied, a first ground port connected to the input terminal with a resistor in between, and a second ground port connected to a ground.
16. 16 . The driver drill according to claim 15 , wherein the plurality of mode sensors include a first mode sensor and a second mode sensor, the resistor includes a first resistor connected to the first mode sensor, and a second resistor connected to the second mode sensor, with the speed switch lever at a first position to switch the speed mode to a first speed mode, the output terminal outputs an output signal at a first level, with the speed switch lever at a second position to switch the speed mode to a second speed mode, the output terminal outputs an output signal at a second level, and with the speed switch lever at a third position to switch the speed mode to a third speed mode, the output terminal outputs an output signal at a voltage level resulting from voltage division with a resistance of the first resistor and a resistance of the second resistor.
17. 17 . The driver drill according to claim 8 , wherein the plurality of mode sensors are turned on to connect the first ground port and the second ground port in response to detecting the permanent magnet, and are turned off not to connect the ground port and the ground port in response to detecting no permanent magnet.
18. 18 . The driver drill according to claim 17 , wherein the first position is defined rearward from the second position, the second position is defined rearward from the third position, the first mode sensor is located to detect the permanent magnet with the speed switch lever at the first position, and located not to detect the permanent magnet with the speed switch lever at the second position or the third position, and the second mode sensor is located to detect the permanent magnet with the speed switch lever at the third position, and located not to detect the permanent magnet with the speed switch lever at the first position or the second position.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to Japanese Patent Application No. 2022-030116, filed on Feb. 28, 2022, the entire contents of which are hereby incorporated by reference. BACKGROUND 1. Technical Field The present disclosure relates to an electric work machine and a driver drill. 2. Description of the Background In the field of electric work machines, an electronic clutch driver drill is known as described in Japanese Unexamined Patent Application Publication No. 2021-024043 (hereafter, Patent Literature 1). The driver drill described in Patent Literature 1 includes a motor, an output shaft rotatable by the motor, and a transmission between the motor and the output shaft. A speed switch lever is operable to switch between a high-speed mode in which the transmission rotates the output shaft at a high speed and a low-speed mode in which the transmission rotates the output shaft at a low speed. The electronic clutch driver drill includes a controller that estimates the output torque of the output shaft. The controller stops rotating the motor in response to the estimated output torque being higher than or equal to preset clutch operation torque. BRIEF SUMMARY The driver drill in Patent Literature 1 includes a sensor that can detect the high-speed mode and the low-speed mode. The sensor transmits detection signals to the controller through lead wires. The use of more lead wires can reduce the internal space of a housing in the driver drill or cause difficulty in assembling the driver drill. One or more aspects of the present disclosure are directed to a technique for avoiding use of more lead wires. A first aspect of the present disclosure provides an electric work machine, including: an operation unit operable in an operation mode of at least three operation modes;an operable member movable to switch the operation mode;a plurality of mode sensors located in a direction of movement of the operable member to detect the operable member, the plurality of mode sensors being equal in number to or fewer than the at least three operation modes;a mode sensor board on which the plurality of mode sensors are mounted, the mode sensor board including an output terminal connected to the plurality of mode sensors; anda controller board connected to the output terminal with an output lead wire to determine the operation mode based on an output signal output from the output terminal. A second aspect of the present disclosure provides an electric work machine, including: an operation unit operable in an operation mode of a plurality of operation modes;an operable member movable to switch the operation mode;a plurality of mode sensors located in a direction of movement of the operable member to detect the operable member, the plurality of mode sensors being connected in parallel with one another;a mode sensor board on which the plurality of mode sensors are mounted, the mode sensor board including an output terminal connected to the plurality of mode sensors; anda controller board connected to the output terminal with an output lead wire to determine the operation mode based on an output signal output from the output terminal,wherein each of the plurality of mode sensors is connected to the output terminal with a signal line. A third aspect of the present disclosure provides a driver drill, including: a motor;a first planetary gear assembly including a first stage including a plurality of first planetary gears surrounding a sun gear rotatable by the motor and a first internal gear surrounding the plurality of first planetary gears, anda second stage having a reduction ratio different from a reduction ratio of the first stage and including a plurality of second planetary gears surrounding the sun gear and a second internal gear surrounding the plurality of second planetary gears; a second planetary gear assembly located frontward from the first planetary gear assembly to be actuated by a rotational force from the first planetary gear assembly;a spindle rotatable by a rotational force from the motor transmitted through the second planetary gear assembly;a housing including a motor compartment accommodating the motor;a first speed switch assembly switchable between a first reduction mode in which rotation of the second internal gear is prevented and rotation of the first internal gear is permitted, and a second reduction mode in which rotation of the first internal gear is prevented and rotation of the second internal gear is permitted;a second speed switching assembly switchable between an enabled mode in which rotation of an internal gear in the second planetary gear assembly is prevented, and a disabled mode in which rotation of the internal gear is permitted;an operable member movable to a first position, a second position, and a third position relative to the motor compartment; and two mode sensors configured to detect a position of the operable member, w