Electric power tool

Abstract

To provide an electric work machine capable of suppressing a decrease in work accuracy and work efficiency, when a system error occurs in a microcomputer for controlling a motor.SOLUTION: An electric work machine according to one aspect of the present disclosure includes a motor, a trigger switch, a tip tool, a first microcomputer and a second microcomputer. When rebooted by receiving a reset signal during the energization of the motor, the first microcomputer restarts the energization of the motor in the case where a rotation error is any one of sudden acceleration, sudden deceleration and overspeed of the motor and where an on-state of the trigger switch is detected.SELECTED DRAWING: Figure 14A

Description

Technical Field

[0001] The present disclosure relates to a power-operated work machine.

Background Art

[0002] The electric pliers described in Patent Document 1 stop the motor when the behavior of the motor controlled by the control unit is different from the behavior of the motor indicated by the operation signal of the trigger switch.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the work performed using a power-operated work machine is a force work, a high torque and a high rotational speed are required for the motor of the power-operated work machine. To meet this requirement, a large current flows through the motor, and a large current also flows through the motor driver. The semiconductor switching element included in the motor driver switches the large current flowing through the motor in order to rotate the motor. As a result, large switching noise is generated from the motor driver.

[0005] Each component mounted on the control circuit of the power-operated work machine is constantly exposed to this switching noise during motor rotation, and further, since it is also probabilistically affected by the surrounding environment, the possibility of malfunction cannot be denied. In particular, an IC in which many components are integrated, especially a microcomputer, has a higher probability of malfunctioning than other components, that is, the probability of a system error occurring in the microcomputer is relatively high. Furthermore, the possibility that a system error occurs simultaneously in one or a plurality of microcomputers cannot be denied.

[0006] If the motor continues to be controlled by the microcomputer in which a system error has occurred, the working accuracy of the electric working machine may decrease. For example, work (processing) mistakes may occur, and the workpiece to be machined may be discarded. Therefore, when a system error occurs in one or more microcomputers, it is desirable to stop the motor. However, if the stoppage of the motor continues, the working efficiency decreases.

[0007] One aspect of the present disclosure provides an electric working machine capable of suppressing a decrease in working accuracy and working efficiency when a system error occurs in a microcomputer that controls a motor.

Means for Solving the Problems

[0008] An electric working machine according to one aspect of the present disclosure includes a motor, a trigger switch, a tip tool, a first microcomputer, and a second microcomputer. The motor is configured to generate a rotational force. The trigger switch is configured to drive the motor when it is turned on and stop the motor when it is turned off. The tip tool is configured to be driven by the rotational force. The second microcomputer includes a rotation error detection unit and a signal output unit. The rotation error detection unit is configured to detect a rotation error of the motor. The signal output unit is configured to output a reset signal to the first microcomputer when a rotation error is detected by the rotation error detection unit. The first microcomputer includes a first trigger detection unit and a power supply control unit. The first trigger detection unit is configured to detect the state of the trigger switch. The power supply control unit is configured to restart the power supply to the motor when a reset signal is received and restarted during energization of the motor, the rotation error is any one of a sudden acceleration, a sudden deceleration, and an overspeed of the motor, and the first trigger detection unit detects that the trigger switch is turned on.

[0009] In the above electric power tool, when a first microcomputer malfunctions and a rotation error occurs, a reset signal is output from the second microcomputer to the first microcomputer, and the first microcomputer restarts. The time from when a rotation error occurs due to the malfunction of the first microcomputer until the first microcomputer receives the reset signal and restarts is very short. Therefore, immediately after the first microcomputer restarts, the motor is coasting at the same rotational speed as when the rotation error was detected. Also, when restarted, the first microcomputer has returned to normal operation. Even if the first microcomputer, which is operating normally, immediately resumes power supply to the motor that has stopped energization and is coasting after any one of the errors of rapid acceleration, rapid deceleration, and speed excess occurs, no large reaction torque is generated. Therefore, when the rotation error is any one of rapid acceleration, rapid deceleration, and speed excess of the motor, by resuming power supply to the motor before the trigger switch is turned off, it is possible to suppress a decrease in work accuracy and work efficiency.

[0010] The signal output unit may be configured to output a specific error signal to the first microcomputer in addition to the reset signal when the type of rotation error detected by the rotation error detection unit is any one of rapid acceleration, rapid deceleration, and speed excess.

[0011] When the type of rotation error is any one of rapid acceleration, rapid deceleration, and speed excess, a specific error signal is output from the second microcomputer to the first microcomputer in addition to the reset signal. Thereby, when the rotation error is any one of rapid acceleration, rapid deceleration, and speed excess, the first microcomputer can resume power supply to the motor before the trigger switch is turned off.

[0012] The power supply control unit may be configured to resume power supply to the motor when the first microcomputer receives the specific error signal and the first trigger detection unit detects that the trigger switch is turned on when the first microcomputer restarts.

[0013] When the first microcomputer receives a specific error signal and detects that the trigger switch is turned on when restarted, it can resume power supply to the motor and suppress a decrease in work efficiency.

[0014] The second microcomputer may further include a second trigger detection unit configured to detect the state of the trigger switch. The signal output unit may be configured to stop outputting the reset signal and stop outputting the specific error signal after it is detected by the second trigger detection unit that the trigger switch is turned off.

[0015] When the first microcomputer restarts and it is detected that the trigger switch is turned off, output of the specific error signal becomes unnecessary. Therefore, by stopping output of the specific error signal after stopping output of the reset signal and after it is detected that the trigger switch is turned off, output of unnecessary signals can be suppressed.

[0016] The power supply control unit may be configured to stop power supply to the motor when the first microcomputer restarts, has not received the specific error signal, and it is detected by the first trigger detection unit that the trigger switch is turned on.

[0017] As a rotation error other than sudden acceleration, sudden deceleration, and speed excess, there is an error in which the actual rotation direction of the motor is different from the set rotation direction. When the first microcomputer restarts and resumes power supply to the motor while the motor is coasting in the direction opposite to the set rotation direction, a large reaction torque occurs suddenly due to the change in the actual rotation direction, and the work accuracy decreases. Therefore, when the first microcomputer has not received the specific error signal when it restarts itself, it stops power supply to the motor. Thereby, a decrease in work accuracy can be suppressed.

[0018] When the first microcomputer restarts, the energization control unit may be configured to stop energizing the motor when the rotational speed of the motor is equal to or lower than a predetermined value. If the first microcomputer restarts during the inertial rotation of the motor at a sufficiently low rotational speed and resumes energization of the motor, the rotational speed of the motor will suddenly increase from a substantially stopped state. As a result, a large reaction torque will suddenly occur and the working accuracy will decrease. Therefore, when the first microcomputer restarts and the rotational speed of the motor is equal to or lower than a predetermined value, the first microcomputer stops energizing the motor. Thereby, when the first microcomputer restarts, it is possible to suppress a sudden increase in the rotational speed without the user's intention. As a result, it is possible to suppress a decrease in working accuracy.

[0019] When the signal output unit outputs a reset signal, if the rotational speed of the motor is equal to or lower than a predetermined value, the signal output unit may be configured to continue outputting the reset signal until the second trigger detection unit detects that the trigger switch is turned off.

[0020] The first microcomputer restarts after the output of the reset signal stops. Therefore, when the reset signal is output until the trigger switch is turned off, the first microcomputer restarts after the trigger switch is turned off. That is, the first microcomputer does not restart until the user intentionally turns off the trigger switch. Thereby, when the first microcomputer restarts, it is possible to suppress a sudden increase in the rotational speed without the user's intention from a substantially stopped state of the motor.

[0021] The electric working machine may further include a direction setting unit configured to indicate the rotational direction of the motor. The rotation error detection unit may be configured to detect, as a rotation error, a discrepancy between the rotational direction set by the direction setting unit and the actual rotational direction of the motor. The signal output unit may be configured to stop outputting a specific error signal when the rotation error detection unit detects a discrepancy as a rotation error.

[0022] When the second microcomputer detects a discrepancy between the set rotation direction and the actual rotation direction as a rotation error, it does not output a specific error signal. As a result, when the first microcomputer restarts, if the set rotation direction and the actual rotation direction are different, the power supply to the motor is stopped. Therefore, when the first microcomputer restarts, it is possible to suppress the sudden occurrence of a large reaction torque and suppress a decrease in working accuracy.

[0023] When the first microcomputer restarts, if the energization control unit has not received a specific error signal and the first trigger detection unit has detected that the trigger switch is on, the energization control unit may stop the power supply to the motor until the first trigger detection unit detects that the trigger switch is off and then the first trigger detection unit detects that the trigger switch is on again.

[0024] This can suppress the occurrence of a large reaction torque at an unintended timing when the first microcomputer recovers from a system error and suppress a decrease in working accuracy.

[0025] The rotation error detection unit may detect a rapid acceleration as a rotation error when the rotational acceleration of the motor differs from the acceleration allowable value. Also, the error detection unit may detect a rapid deceleration as a rotation error when the rotational deceleration of the motor differs from the deceleration allowable value. Further, the error detection unit may be configured to detect an overspeed as a rotation error when the rotational speed of the motor differs from the speed allowable value. By detecting the rapid acceleration, rapid deceleration, and overspeed of the motor, the first microcomputer can be reset.

[0026] The second microcomputer may further include a second trigger detection unit configured to detect the state of the trigger switch. The rotation error detection unit may be configured to detect a rotation error at least while the trigger switch is detected to be on by the second trigger detection unit. By detecting a rotation error at least while the trigger switch is on, it is possible to detect a malfunction of the motor and reset the first microcomputer.

[0027] The second microcomputer may further include a current detection unit configured to detect the value of the current flowing through the motor. The rotation error detection unit may be configured to obtain the rotational deceleration rate of the motor when the trigger switch is detected to be on by the first trigger detection unit and the value of the current detected by the current detection unit is 0.

[0028] When the trigger switch is on and the value of the current driving the motor is 0, by obtaining the rotational deceleration rate of the motor, it is possible to obtain the rotational deceleration rate due to a system error of the first microcomputer, rather than the deceleration of the tip tool caused by the handling of the electric working machine by the user, that is, the rotational deceleration rate of the motor due to heavy load work.

[0029] The electric working machine may further include a first energization circuit provided in the supply line from the power supply source to the motor. The second microcomputer may include a first cutoff unit, a second trigger detection unit, and a first energization unit. The first cutoff unit may be configured to output a first cutoff signal to the first energization circuit to cutoff the first energization circuit when a discrepancy is detected as a rotation error by the rotation error detection unit. The second trigger detection unit may be configured to detect the state of the trigger switch. The first energization unit may be configured to output a first energization signal to the first energization circuit to energize the first energization circuit when the second trigger detection unit detects that the trigger switch is off after the energization to the motor is cutoff by the first cutoff unit.

[0030] After the power supply to the motor is cut off, in response to detecting that the trigger switch has been turned off, by outputting a power-on signal to the first power-on circuit, it is possible to avoid an unexpected restart of the motor by the user.

[0031] The first cutoff section may be configured to output a first cutoff signal to the first power-on circuit when the power supply voltage input to the second microcomputer drops. When the power supply voltage drops for some reason, the first power-on circuit can be cut off.

[0032] The electric power tool may further include a second power-on circuit provided in the supply line. The first microcomputer may further include a second cutoff section, a signal detection section, and a second power-on section. The second cutoff section may be configured to output a second cutoff signal to the second power-on circuit to cut off the second power-on circuit. The signal detection section may be configured to detect the first cutoff signal output from the first cutoff section or the first power-on signal output from the first power-on section. The second power-on section is configured to output a second power-on signal to the second power-on circuit to energize the second power-on circuit in response to detecting that the trigger switch has been turned off by the first trigger detection section and the first power-on signal has been detected by the signal detection section after the second power-on circuit has been cut off by the second cutoff section when the first microcomputer is restarted and the first microcomputer has not received a specific error signal, and then detecting that the trigger switch has been turned on by the first trigger detection section.

[0033] When a cutoff signal is input to the first power-on circuit and the user switches the trigger switch to the on position and the first microcomputer tries to start the rotation of the motor, since the first power-on circuit is cut off, the first microcomputer cannot start the rotation of the motor and the stop of the motor continues. In contrast, after the first microcomputer detects a power-on signal to the first power-on circuit and then energizes the second power-on circuit, it is possible to suppress the motor from not starting to rotate when the first microcomputer tries to start the rotation of the motor.

Brief Description of the Drawings

[0034]

Figure 1

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Figure 15B

[0035] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. (First embodiment) <1. Configuration> <1-1. Overall composition> First, the overall configuration of an electric working machine 1 according to this embodiment will be described with reference to Figures 1 and 2. In this embodiment, a grass cutter, which is one type of electric working machine 1, will be described as an example.

[0036] The electric working machine 1 includes a main pipe 2, a control unit 3, a drive unit 4, and a handle 8. The control unit 3 is provided on the rear end side of the main pipe 2. The drive unit 4 is provided on the front end side of the main pipe 2.

[0037] The control unit 3 has a built-in controller. A battery pack 400 is attached to the rear end surface of the control unit 3. The battery pack 400 includes a multiprocessor unit and a battery 300, which will be described later. The battery 300 is, for example, a lithium ion battery having a plurality of battery cells connected in series.

[0038] In addition, the control unit 3 is provided with a main power switch 11, a first display unit 15, and a second display unit 16. The main power switch 11 is a switch for enabling the electric working machine 1 to be used. When the user turns on the main power switch 11, power is supplied from the battery 300 to the control unit 3. The first display unit 15 has one or more LEDs, and lights, blinks, or turns off one or more LEDs to notify whether the electric working machine 1 is in a usable state. The second display unit 16 has one or more LEDs, and lights, blinks, or turns off one or more LEDs to notify the state of the battery 300, specifically, a decrease in charge capacity, an over-temperature state, an over-current state, etc.

[0039] The drive unit 4 includes a motor housing 18 and a cutting blade 17. The cutting blade 17 is a disc-shaped blade for cutting objects to be cut such as grass and small-diameter trees, and is configured to be detachable from the motor housing 18. The motor housing 18 houses a motor 40 described later inside. The motor 40 generates a rotational force for rotating the cutting blade 17. In the present embodiment, the cutting blade 17 corresponds to an example of the tip tool of the present disclosure.

[0040] The handle 8 is formed in a U shape and is connected to the main pipe 2 at a substantially intermediate position in the length direction of the main pipe 2. Various operation parts that can be operated by the user's right hand are provided on the right side of the handle 8. The various operation parts include a trigger switch 240, a forward / reverse switch 260, etc. The trigger switch 240 is pulled by the user to instruct the rotation of the cutting blade 17 (i.e., the trigger switch 240 is turned on), and is released to instruct the stop of the cutting blade 17 (i.e., the trigger switch 240 is turned off). The forward / reverse switch 260 is a switch for switching the rotation direction of the motor 40 to either the forward rotation direction or the reverse rotation direction. The various operation parts are connected to the control unit 3 via a control wiring pipe 13.

[0041] Note that the electric working machine 1 is not limited to a lawn mower. The electric working machine 1 is not particularly limited as long as it is a working machine including a motor 40 and a tip tool driven by receiving the rotational force of the motor 40. The electric working machine 1 may be a gardening tool other than a lawn mower or an electric tool. Examples of gardening tools other than a lawn mower include a hedge trimmer, an electric chain saw, etc. Examples include a grinder, an electric saw, an electric chain saw, etc. Examples of electric tools include a grinder, an electric saw, a driver drill, etc.

[0042] <1-2. Electrical configuration> Next, the electrical configuration of the electric working machine 1 will be described with reference to FIG. 2. The electric working machine 1 includes a main microcomputer (hereinafter, main microcomputer) 30, a monitoring microcomputer (hereinafter, monitoring microcomputer) 60, a motor 40, a position sensor 41, a motor driver 42, a current detection circuit 43, and an overcurrent detection latch circuit 44.

[0043] Furthermore, the electric working machine 1 includes a charge pump circuit 34, a boost converter 35, a voltage guarantee circuit 36, a regulator 37, a first switch 38, a second switch 39, a battery voltage detection circuit 52, a temperature detection circuit 51, a surge killer capacitor 53, a high-side driver 54, a third switch 55, a trigger switch 240, a forward / reverse switch 260, and a signal terminal 270.

[0044] The main microcomputer 30 includes a CPU 30a, a memory 30b, I / O, etc. The memory 30b includes a ROM, a RAM, a register, etc. The main microcomputer 30 executes rotation control processing of the motor 40 by the CPU 30a executing various programs stored in the memory 30b. Details of the rotation control processing will be described later. In the present embodiment, the main microcomputer 30 corresponds to an example of the first microcomputer of the present disclosure.

[0045] Also, the main microcomputer 30 turns the second switch 39 on or off, and the second switch 39 is turned off by the main microcomputer 30 during reset. The monitoring microcomputer 60 includes a CPU 60a, a memory 60b, a watchdog timer (hereinafter referred to as WDT) 65, I / O, etc. The memory 60b includes a ROM, a RAM, registers, etc. The monitoring microcomputer 60 executes a monitoring process of the operation of the motor 40 by the CPU 60a executing various programs stored in the memory 60b. Details of the monitoring process will be described later. The WDT 65 is a timer independent of the CPU 60a. In the present embodiment, the monitoring microcomputer 60 corresponds to an example of the second microcomputer of the present disclosure.

[0046] Also, the signal output by the monitoring microcomputer 60 is input to the high-side driver 54, and the high-side driver 54 turns on or off the third switch 55 according to the signal input from the monitoring microcomputer 60. The signal input from the monitoring microcomputer 60 during reset turns off the third switch 55.

[0047] Also, the main microcomputer 30 is reset by the reset signal output by the monitoring microcomputer 60, but the monitoring microcomputer 60 during reset cannot output the reset signal and cannot reset the main microcomputer 30.

[0048] The motor 40 is a three-phase (i.e., U-phase, V-phase, W-phase) brushless motor. The motor driver 42 is a three-phase full-bridge circuit and has three switching elements provided on the high side and three switching elements provided on the low side. The motor driver 42 is provided in the power supply path for supplying power from the battery 300 to the motor 40. The six switching elements included in the motor driver 42 are turned on or off by a control signal output from the main microcomputer 30. The switching element is, for example, an electrolytic effect transistor. In the present embodiment, the motor driver 42 corresponds to an example of the second energization circuit of the present disclosure.

[0049] The position sensor 41 is a sensor that detects the position of the rotor of the motor 40. The position sensor 41 has three Hall ICs. The three Hall ICs are installed at positions corresponding to the windings of the stators of the U-phase, V-phase, and W-phase, respectively. The position sensor 41 outputs the position signals respectively output by the three Hall sensors detecting that the magnetic pole of the rotor has changed from the S pole to the N pole or from the N pole to the S pole to the main microcomputer 30 and the monitoring microcomputer 60.

[0050] From this position signal, a control signal corresponding to the position of the rotor is generated. The position signal includes information for specifying the Hall IC as the output source, that is, information for specifying from which Hall IC of the U-phase, V-phase, or W-phase the signal is output, and the direction of the output signal. Also, from the position signal, the rotational speed, rotational acceleration, rotational deceleration, and rotational direction of the motor 40 are calculated.

[0051] Here, if there is at least one phase signal among the signals output from the Hall ICs of the U-phase, V-phase, and W-phase, the rotational speed, rotational acceleration, and rotational deceleration of the motor 40 can be calculated, and if there are at least two phase signals, the rotational direction can also be calculated.

[0052] The current detection circuit 43 detects the value of the current flowing out from the motor driver 42, that is, the value of the drive current (hereinafter referred to as the drive current value) for driving the motor 40. Then, the current detection circuit 43 outputs the detected drive current value to the main microcomputer 30, the monitoring microcomputer 60, and the overcurrent detection latch circuit 44. The drive current value output from the current detection circuit 43 is an analog signal.

[0053] The regulator 37 is connected to the battery 300 via the power supply path L1 and the first switch 38. The regulator 37 generates a power supply of a predetermined voltage from the power supplied from the battery 300 and supplies it to each circuit of the electric working machine 1 connected to the power supply. In this embodiment, the predetermined voltage is 5V.

[0054] The voltage guarantee circuit 36 ensures that when the value of the power supply voltage generated and output by the regulator 37 deviates from the lower limit value or the upper limit value within the tolerance range of the power supply voltage, the circuit operation stops, that is, the motor 40 stops. When the value of the input voltage of each component connected to the predetermined voltage output by the regulator 37 exceeds the upper limit value (for example, the absolute maximum rated voltage), there is a possibility that the component exceeding the withstand voltage may fail. When a component fails, it may not be possible to predict how the subsequent behavior of the electric working machine 1 and the rotational operation of the motor 40 will be.

[0055] Also, when the value of the voltage applied to each component is below the lower limit value (for example, the minimum operating guarantee voltage), although there is no possibility of component failure at low voltage, there is a possibility that the intended operation cannot be performed. For example, when analog values are AD-converted to digital values, the reference voltage required for comparing the analog values for magnitude comparison decreases as the power supply voltage decreases. Therefore, since the reference voltage itself of the comparison source changes, there is a possibility that the input analog signal cannot be converted into the correct digital value.

[0056] Therefore, the voltage guarantee circuit 36 is configured such that when the power supply voltage output from the regulator 37 exceeds the upper limit value, power is not supplied to each component, and when it is below the lower limit value, a reset signal is output to the monitoring microcomputer 60 so that the operation of the electric working machine 1 stops. In this embodiment, the lower limit value is 4.5 V and the upper limit value is 5.5 V.

[0057] The voltage guarantee circuit 36 includes a first guarantee circuit 36a and a second guarantee circuit 36b. The first guarantee circuit 36a directly monitors whether the power supply voltage output by the regulator 37 exceeds the upper limit voltage, and suppresses the power supply voltage value from exceeding the upper limit value. Specifically, when the value of the power supply voltage reaches the upper limit value, the first guarantee circuit 36a immediately switches the first switch 38 off to cut off the power supply path L1 that supplies power from the battery 300 to the regulator 37. Thereby, the value of the power supply voltage does not exceed the upper limit value, and each component does not fail due to overvoltage, preventing the occurrence of unpredictable product operations. Furthermore, since the regulator 37 is cut off from the power supply path L1, the power supply to the control circuits including the main microcomputer 30 and the monitoring microcomputer 60 is also cut off, so the motor 40 cannot rotate.

[0058] The second guarantee circuit 36b monitors whether the power supply voltage output by the regulator 37 is lower than the lower limit voltage via the second switch 39. When the value of the power supply voltage is lower than the lower limit value while the second switch 39 is on, the second guarantee circuit 36b cuts off the power supply to the motor 40. Specifically, while the value of the power supply voltage is lower than the lower limit value, the second guarantee circuit 36b continuously outputs a reset signal to the monitoring microcomputer 60.

[0059] Here, the second switch 39 is switched on in the active mode described later and off in the sleep mode. Also, the input of the second switch 39 is connected to the power supply voltage output by the regulator 37, and the output of the second switch 39 is connected to the power input terminal of the monitoring microcomputer 60 or the like. That is, the second guarantee circuit 36b monitors whether the output voltage of the second switch 39 is lower than the lower limit voltage.

[0060] When in the active mode, monitoring the output voltage of the second switch 39 is substantially the same as directly monitoring the power supply voltage output by the regulator 37. When in the sleep mode, the power supply voltage is cut off and the output voltage of the second switch 39 decreases. Therefore, the second guarantee circuit 36b outputs a reset signal to the monitoring microcontroller 60. That is, during the sleep mode, whether the power supply voltage output by the regulator 37 falls below the lower limit voltage is not monitored.

[0061] During the sleep mode, the motor 40 does not rotate and no noise is generated due to the rotation control of the motor 40. Therefore, the possibility that the power supply voltage fluctuates due to a malfunction of the regulator 37 is relatively low. Also, during the sleep mode, since the motor 40 cannot rotate, even if the power supply voltage drops, it will not affect the working accuracy. Therefore, during the sleep mode, it can be replaced by a simple low-voltage monitoring function built into the main microcontroller 30. The simple low-voltage monitoring function has the same function as the second guarantee circuit 36b. Furthermore, during the sleep mode, since the current flowing through the second guarantee circuit 36b is cut off, the power consumption can be reduced.

[0062] On the other hand, if for some reason the power supply voltage rises during the sleep mode, it cannot be denied that the components connected to the power supply may suffer from overvoltage failure even during the sleep mode. If a component fails, there is a risk that the working accuracy will decrease during subsequent use of the electric working machine 1. Therefore, even during the sleep mode, the first guarantee circuit 36a continues to monitor the power supply voltage.

[0063] Also, a capacitor 39a is connected to the output terminal of the second switch 39 so that the power supply voltage of the monitoring microcontroller does not immediately drop after the second switch 39 is switched off.

[0064] Therefore, after a predetermined time has elapsed since the second switch 39 is switched off, the second guarantee circuit 36b outputs a reset signal to the monitoring microcomputer 60. That is, the monitoring microcomputer 60 can operate until a predetermined time elapses since the second switch 39 is switched off.

[0065] Furthermore, the monitoring microcomputer 60 is configured such that a cutoff signal is output to the high-side driver 54 so that the third switch 55 is turned off during the reset of the monitoring microcomputer 60. Therefore, when the monitoring microcomputer 60 is in a reset state, the third switch 55 is turned off by the monitoring microcomputer 60, so that the motor driver 42 is not energized and the motor 40 cannot rotate.

[0066] The boost converter 35 boosts the value of the power supply voltage generated by the regulator 37. In the present embodiment, the boost converter 35 boosts a voltage of 5V to 15V. The boosted voltage is supplied as a power supply for the motor driver 42 and also as a power supply for the charge pump circuit 34.

[0067] The charge pump circuit 34 receives the battery voltage and the boosted voltage. The charge pump circuit 34 superimposes the boosted voltage on the input battery voltage. That is, a voltage higher than the battery voltage is created and supplied as a secondary-side power supply for the high-side driver 54.

[0068] The trigger switch 240 includes a first trigger circuit 240a and a second trigger circuit 240b. The first trigger circuit 240a is composed of signal contacts, and the signal contacts open and close in conjunction with the operation of the trigger switch 240. Therefore, the first trigger signal output by the first trigger circuit 240a changes depending on whether the trigger switch 240 is on or off. The first trigger circuit 240a outputs the first trigger signal to the main microcomputer 30, the monitoring microcomputer 60, the high-side driver 54, and the overcurrent detection latch circuit 44.

[0069] The second trigger circuit 240b has a sliding resistor, and in conjunction with the operation of the trigger switch 240, the resistance value of the sliding resistor changes continuously. Also, the resistance value of the sliding resistor of the second trigger circuit 240b is different at the on position of the trigger switch 240 (i.e., from the starting position of the trigger switch 240 where the motor 40 starts to rotate to the ending position of the trigger switch 240 where it reaches full-speed rotation) and the off position (i.e., the release position where the motor 40 is stopped).

[0070] Also, the resistance value that changes continuously according to the amount of pulling of the trigger switch 240 corresponds to the speed command value of the rotation speed of the motor 40. The second trigger circuit 240b outputs a second trigger operation signal corresponding to the resistance value of the sliding resistor to the main microcomputer 30. The second trigger operation signal is an analog signal.

[0071] Also, when the trigger switch 240 is in the on position and the off position, the second trigger circuit 240b outputs an analog value corresponding to that position. That is, since the analog value output in the on position is different from the analog value output in the off position, the main microcomputer 30 can determine the on position and the off position of the second trigger circuit 240b from the input analog signal.

[0072] Here, when starting to pull the trigger switch 240, the amount of pulling of the trigger switch 240 when reaching the on-signal output start position of the second trigger circuit 240b (i.e., the position where the motor 40 starts to rotate) is smaller than the amount of pulling when reaching the on-signal output start position of the first trigger circuit 240a (i.e., the position where the signal contact changes to on).

[0073] That is, when starting to pull the trigger switch 240, a very slow speed signal for starting the rotation of the motor 40 is output from the second trigger circuit 240b first, and then the first trigger circuit 240a becomes on output.

[0074] Thus, when the first trigger circuit 240a outputs an on signal, since a slow-speed signal for starting the rotation of the motor 40 has already been output from the second trigger circuit 240b, the motor 40 can be started simultaneously with the on state of the first trigger circuit 240a.

[0075] Also, when the trigger switch 240 starts to be pulled back from the pulled state, the amount of pull of the trigger switch 240 when reaching the off signal output start position of the second trigger circuit 240b (i.e., the position for stopping the motor 40) is smaller than the amount of pull of the trigger switch 240 when reaching the off signal output start position of the first trigger circuit 240a (i.e., the position where the signal contact changes to off).

[0076] That is, when the amount of pull of the trigger switch 240 is returned, a signal for stopping the motor 40 is output from the second trigger circuit 240b first, and then the first trigger circuit 240a outputs an off signal.

[0077] Accordingly, when the main microcomputer 30 determines that the first trigger signal input from the first trigger circuit 240a is on, the second trigger operation signal input from the second trigger circuit 240b is already at a value indicating an on state, and when the first trigger signal is determined to be off, the second trigger operation signal is already at a value indicating an off state.

[0078] In this embodiment, the reliability of the trigger signal input from the trigger switch 240 is confirmed by the coincidence of the on / off determination value of the first trigger signal input from the first trigger circuit 240a and the on / off determination value of the second trigger operation signal input from the second trigger circuit 240b.

[0079] The forward / reverse switch 260 is operated by the user to indicate the rotation direction of the motor 40. The rotation direction is either the forward rotation direction or the reverse rotation direction. When the rotation direction of the motor 40 changes, the rotation direction of the saw blade 230 also changes. The forward / reverse switch 260 includes a first forward / reverse circuit 260a and a second forward / reverse circuit 260b. The first forward / reverse circuit 260a outputs a first rotation direction signal indicating the rotation direction indicated by the forward / reverse switch 260 to the main microcomputer 30 and the monitoring microcomputer 60. The second forward / reverse circuit 260b outputs a second rotation direction signal to the main microcomputer 30. In the present embodiment, the reliability of the operation signal of the forward / reverse switch 260 is confirmed by the coincidence of the first rotation direction signal and the second circuit direction signal.

[0080] The signal terminal 270 is connected to the battery signal terminal provided in the battery 300. When the battery 300 is in a state where it cannot be discharged, the battery 300 transmits a discharge prohibition signal to the main microcomputer 30 via the signal terminal 270. The state where discharge is impossible is, for example, an over-discharged state, an over-heated state, or the like. Further, when the battery 300 is in a state where it can be discharged, the battery 300 transmits a discharge permission signal to the main microcomputer 30 via the signal terminal 270.

[0081] The second switch 39 is provided in the power supply path from the regulator 37 to the monitoring microcomputer 60. The second switch 39 is turned on or off by the main microcomputer 30. When the off state of the trigger switch 240 continues for a predetermined period, that is, when the electric working machine 1 is not used for a predetermined period, the main microcomputer 30 enters the sleep mode in order to suppress power consumption. When the main microcomputer 30 enters the sleep mode, the second switch 39 is switched off to cut off the power supply path from the regulator 37 to circuits such as the monitoring microcomputer 60 that do not need to be operated during the period when the electric working machine 1 is not used, and suppress the consumption of the remaining energy of the battery 300.

[0082] The input terminal of the second switch 39 is connected to the power supply voltage output by the regulator 37, and the output terminal of the second switch 39 is connected to the capacitor 39a and the power supply input terminal of the monitoring microcomputer 60 and the like.

[0083] The capacitor 39a is connected between the output terminal of the second switch 39 and GND. The capacitance of the capacitor 39a is set to a value at which the monitoring microcomputer can operate for a predetermined time after the second switch 39 is switched off.

[0084] The surge killer capacitor 53 is provided in the power supply path L2 from the battery 300 to the motor driver 42. The surge killer capacitor 53 absorbs the surge voltage and the regenerative current generated when a malfunction occurs in the rotational control of the motor 40.

[0085] The third switch 55 is provided in the power supply path L2 from the battery 300 to the motor driver 42. Specifically, it is provided between the surge killer capacitor 53 and the battery 300. In the present embodiment, the third switch 55 corresponds to an example of the first energization circuit of the present disclosure.

[0086] The high-side driver 54 is a circuit that switches the third switch 55 on or off. The high-side driver 54 turns the third switch 55 on or off based on the energization signal or the cut-off signal output by the monitoring microcomputer 60, the overcurrent detection latch circuit 44, and the first trigger circuit 240a, respectively. The monitoring microcomputer 60 outputs the generated energization signal or cut-off signal to the high-side driver 54 and the main microcomputer 30. When the third switch 55 is on, the power supply path L2 from the battery 300 to the motor driver 42 is conductive, and when the third switch 55 is off, the power supply path L2 is cut off.

[0087] Further, when the power supply voltage input to the high-side driver 54 drops below the operating guarantee voltage of the high-side driver 54, the high-side driver 54 turns off the third switch 55 even if all the signals input to the high-side driver 54 are energization signals.

[0088] The temperature detection circuit 51 detects the temperature of the switching element included in the motor driver 42. The temperature detection circuit 51 includes a first temperature detection circuit 51a and a second temperature detection circuit 51b. The first temperature detection circuit 51a and the second temperature detection circuit 51b have, for example, a thermistor as a temperature sensor. The first temperature detection circuit 51a and the second temperature detection circuit 51b each detect the temperature at the same temperature location (for example, between the high-side switching elements of the U phase and the V phase and between the V phase and the W phase) in the motor driver 42, and output a first temperature detection signal and a second temperature detection signal to the main microcomputer 30. In the present embodiment, the reliability of the temperature detection signal of the temperature detection circuit 51 is confirmed by the coincidence of the first temperature detection signal and the second temperature signal.

[0089] The battery voltage detection circuit 52 detects the voltage value (hereinafter, battery voltage value) output from the battery 300 via the surge killer capacitor 53. The battery voltage detection circuit 52 includes a first voltage detection circuit 52a and a second voltage detection circuit 52b. The first voltage detection circuit 52a includes a peak hold circuit and detects the maximum value of the battery voltage value. That is, the first voltage detection circuit 52a detects the battery voltage value superimposed with the surge voltage that could not be absorbed by the surge killer capacitor 53. The second voltage detection circuit 52b detects the averaged battery voltage value. Therefore, the battery voltage value detected by the second voltage detection circuit 52b is hardly affected by the surge voltage. The first voltage detection circuit 52a outputs a first voltage detection signal to the main microcomputer 30. The second voltage detection circuit 52b outputs a second voltage detection signal to the main microcomputer 30. In the present embodiment, the reliability of the battery voltage detection signal of the battery voltage detection circuit 52 is confirmed by the coincidence of the first voltage detection signal and the second voltage detection signal when the motor 40 stops.

[0090] Based on the drive current value input from the current detection circuit 43, the main microcomputer 30 determines an overcurrent state. When it determines that it is in an overcurrent state, it outputs a control signal to the motor driver 42 to enter a cutoff state (that is, turn off the three high-side switching elements or turn off the three low-side switching elements), stopping the motor 40. However, this is not the case when a system error has occurred in the main microcomputer 30.

[0091] Here, when the overcurrent detection latch circuit 44 determines an overcurrent state based on the drive current value input from the current detection circuit 43, it outputs a cutoff signal for cutting off the power supply to the motor driver 42 to the high-side driver 54 and the main microcomputer 30. That is, the overcurrent detection latch circuit 44 can cut off the power supply to the motor driver 42 regardless of the operation of the main microcomputer 30.

[0092] Here, the overcurrent detection circuit 44a is a circuit that detects an overcurrent state based on the drive current value input from the current detection circuit 43 and outputs an overcurrent signal to the latch circuit 44b. Furthermore, the latch circuit 44b outputs a cutoff signal to the high-side driver 54 and the main microcomputer 30 based on the input overcurrent signal. The latch circuit 44b is a circuit that maintains the output cutoff signal until the user turns off the trigger switch 240 at the same time as outputting the cutoff signal.

[0093] Also, when the power supply voltage input to the overcurrent detection latch circuit 44 drops below the operating guarantee voltage of the overcurrent detection latch circuit 44, the latch circuit 44b outputs a cutoff signal. The overcurrent detection latch circuit 44 operates in the following situations.

[0094] When a system error occurs in the main microcomputer 30 such that the rotation control operation continues and the main microcomputer 30 cannot stop the motor 40, and the user performs a heavy-load operation, an overcurrent may occur.

[0095] At this time, even if an overcurrent occurs, the main microcomputer 30 cannot stop the motor 40. Instead, the overcurrent detection circuit 44a can cut off the power supply to the motor 40 (i.e., the motor 40 stops), and malfunctions caused by the overcurrent can be prevented.

[0096] Furthermore, the latch circuit 44b prevents the motor 40 from restarting until the user turns off the trigger switch 240. After that, even if the trigger switch 240 is turned off and the latched state is released, since the trigger switch 240 is off, a cutoff signal continues to be input to the high-side driver 54, and the motor 40 remains stopped.

[0097] That is, after the power-operated work machine 1 stops due to an overcurrent, the motor 40 can maintain the stopped state without unexpectedly rotating until the user turns on the trigger switch 240 again (i.e., until it can be confirmed that the user has performed an operation to resume rotation).

[0098] <2. Processing> <2-1. Main Microcomputer Processing> Next, the rotation control process executed by the main microcomputer 30 will be described with reference to FIGS. 3A and 3B. The main microcomputer 30 starts this process when the battery 300 is connected to the power-operated work machine 1 or when the reset state of the main microcomputer 30 is released.

[0099] First, in S10, initialization is executed. Specifically, the main microcomputer 30 initializes the RAM and / or registers and shifts to the active mode. When the main microcomputer 30 enters the active mode, the power supply to the monitoring microcomputer 60 is started, and the power supply to the motor driver 42 becomes possible.

[0100] Subsequently, in S20, a control signal for de-energizing the motor 40 is output to the motor driver 42. That is, a control signal for turning off the six switching elements of the motor driver 42 is output to set the drive current flowing through the windings of the motor 40 to zero.

[0101] Subsequently, in S30, based on the first trigger signal input from the first trigger circuit 240a, it is determined whether the trigger switch 240 is off. If it is determined that the trigger switch 240 is off, the process proceeds to the process of S40. If it is determined that the trigger switch 240 is on, the process of S30 is repeatedly executed until it is determined to be off.

[0102] This is because when the battery 300 is connected and for some reason the trigger switch 240 is in the on position, that is, when it is on even without the user performing a trigger operation, the motor 40 is not rotated.

[0103] After the main microcomputer 30 connects the battery 300 to the electric working machine 1 and detects that the trigger switch 240 is in the off position, the motor 40 is not rotated unless the trigger operation is performed to the on position. That is, unless it can be confirmed that the user has operated the trigger switch 240 to the on position, the rotation of the motor 40 is not started.

[0104] Subsequently, in S40 to S90, a self-check is executed. Among the plurality of control circuits that control the operation of the electric working machine 1, there is a control circuit whose failure affects the working accuracy. Therefore, at this timing before the use of the electric working machine 1 is started, a self-check (i.e., fault diagnosis) of the control circuit whose failure affects the working accuracy is performed.

[0105] Since it is not considered that the failure of the control circuit occurs frequently, a self-check is performed once after the battery 300 is connected and before the motor 40 is rotated. Thereafter, this self-check is not performed until the battery 300 is removed.

[0106] After detecting an error through self-check, the motor 40 is not rotated so as not to reduce the working accuracy. First, in S40, the power supply permission by the monitoring microcomputer 60 is checked. Specifically, in order to turn on the third switch 55, it is determined whether the signal generated by the monitoring microcomputer 60 is a power supply signal. If the cutoff signal for turning off the third switch 55 continues for a predetermined time, it is determined that some abnormality has occurred in the monitoring microcomputer, and the monitoring microcomputer error flag is set.

[0107] Subsequently, in S50, the open circuit and short circuit of the second trigger circuit 240b are checked. Here, from the state where the trigger switch 240 is not operated to the state where the trigger switch 240 is fully pulled, the voltage range of the second trigger operation signal input from the second trigger circuit 240b is a normal voltage range from a value lower than the power supply voltage to a value higher than GND.

[0108] Therefore, when the second trigger operation signal is smaller than the normal voltage range, it is determined that an abnormality has occurred in which the second trigger operation signal and GND are short-circuited (short circuit to ground), and the short circuit to ground error flag is set. Also, when the second trigger operation signal is larger than the normal voltage range, it is determined that an abnormality has occurred in which the second trigger operation signal and the power supply voltage are short-circuited (open circuit), and the open circuit error flag is set.

[0109] Subsequently, in S60, the logic of the forward and reverse switch 260 is checked. Specifically, it is checked whether the first rotation direction signal output from the first forward and reverse circuit 260a matches the second rotation direction signal output from the second forward and reverse circuit 260b. If the rotation directions indicated by the two rotation direction signals do not match, it is determined that some abnormality has occurred, and the rotation direction logic error flag is set.

[0110] Next, in S70, the battery voltage is checked. Specifically, when the first voltage detection signal is out of the normal range, it is determined that an abnormality has occurred where the first voltage detection signal is short-circuited to the power supply voltage (open circuit to the sky) or short-circuited to GND (ground short circuit), and the surge voltage open / ground short circuit error flag is set. Similarly, when the second voltage detection signal is out of the normal range, it is determined that an abnormality has occurred where the second voltage detection signal is open-circuited or grounded, and the battery voltage open / ground short circuit error flag is set.

[0111] Also, when the motor 40 is stopped, no surge voltage is generated, so the first voltage detection signal substantially coincides with the second voltage detection signal. Since the motor 40 is stopped in S70, it is possible to confirm the coincidence between the first voltage detection signal and the second voltage detection signal. Therefore, the difference between the first voltage value detection signal and the second voltage value signal is calculated, and when the difference exceeds a predetermined value, it is determined that some abnormality has occurred, and the battery voltage logic error flag is set.

[0112] Next, in S80, the temperature is checked. Specifically, when the first temperature detection signal is out of the normal range, it is determined that an abnormality has occurred where the first temperature detection signal is short-circuited to the power supply voltage (open circuit to the sky) or short-circuited to GND (ground short circuit), and the first temperature open / ground short circuit error flag is set. Similarly, when the second temperature detection signal is out of the normal range, it is determined that an abnormality has occurred where the second temperature detection signal is open-circuited or grounded, and the second temperature open / ground short circuit error flag is set. Also, when the first temperature detection signal does not match the second temperature detection signal, it is determined that some abnormality has occurred, and the temperature logic error flag is set.

[0113] Next, in S90, the current detection circuit 43 is checked. Specifically, when the measurement conditions of the current detection circuit 43 are changed, it is checked whether the drive current value changes to a predetermined value based on the change conditions. When the drive current value does not change to the predetermined value, it is determined that some abnormality has occurred, and the current detection circuit error flag is set.

[0114] Next, in S95, the presence or absence of an error flag is confirmed. Specifically, it is determined whether or not at least one of a monitoring microcomputer error flag, a ground fault error flag, a sky fault error flag, a rotation direction logic error flag, a surge voltage ground and sky fault error flag, a battery voltage ground and sky fault error flag, a battery voltage logic error flag, a first temperature ground and sky fault error flag, a second temperature ground and sky fault error flag, a temperature logic error flag, and a current detection circuit error flag is set. If none of the error flags are set, the self-check is terminated and the process proceeds to the process of S100. On the other hand, if at least one error flag is set, an error is displayed and the process is terminated. Specifically, the LED of the first display unit 15 is turned on or blinked to terminate the process. That is, after detecting the error flag, the process does not shift to the rotation process of the motor 40, and a decrease in working accuracy is suppressed.

[0115] Subsequently, in S100, based on the first trigger signal input from the first trigger circuit 240a, it is determined whether or not the trigger switch 240 is off. If it is determined that the trigger switch 240 is off, the process proceeds to the process of S110. If it is determined that the trigger switch 240 is on, the process of S100 is repeatedly executed until it is determined that it is off.

[0116] Subsequently, in S110, it is determined whether or not the off state of the trigger switch 240 has continued for a predetermined period. In S110, if it is determined that the off state has continued for a predetermined period, that is, if the time since the user turned off the trigger is long and the possibility of turning on the trigger again is low, the process proceeds to the process of S120. If it is determined that the off state has not continued for a predetermined period, that is, if the time since the user turned off the trigger is short and the possibility of turning on the trigger again is high, the process proceeds to the process of S180.

[0117] In S120, the off state of the trigger switch 240 is self-checked. That is, it is confirmed that the first trigger signal input from the first trigger circuit 240a is off and that the second trigger operation signal input from the second trigger circuit 240b indicates an off state.

[0118] Here, the second trigger operation signal input from the second trigger circuit 240b is an analog signal, and when this analog signal is input to the main microcomputer 30, filtering must be performed to ensure a sufficient signal-to-noise ratio. That is, there must always be a response delay time for the analog signal input to the main microcomputer 30 with respect to the analog signal output by the second trigger circuit 240b.

[0119] The timing for executing S120 is when the trigger switch 240 has not been operated for a period much longer than the response delay time, that is, when the second trigger operation signal has not changed. Therefore, the filtered analog signal input to the main microcomputer 30 and the unfiltered analog signal output by the second trigger circuit 240b have the same value.

[0120] Furthermore, since the trigger switch 240 has not been operated for a predetermined period, the possibility that the trigger switch 240 is operated at the moment when S120 is executed is low. Therefore, the timing for executing S120 is a suitable timing for checking the off state of the trigger switch 240.

[0121] That is, for the check of the off state of the trigger switch 240, since it has already been confirmed immediately before in S110 that the first trigger signal input from the first trigger circuit 240a is on, the off state of the trigger switch 240 is confirmed from the value of the second trigger operation signal, and it is checked whether the first trigger signal and the second trigger operation signal match.

[0122] Specifically, in S120, it is determined whether the second trigger operation signal input from the second trigger circuit 240b has a value indicating an off state. If it is determined that it is in the off state, the check of the off state of the trigger switch 240 is terminated, and the process proceeds to S130. If it is determined that it is not in the off state, it is determined that some abnormality has occurred in the state detection of the trigger switch 240. After setting the switch error flag, the check is terminated, and the process proceeds to S130.

[0123] Subsequently, in S130, it is checked whether there is an error flag. Specifically, it is determined whether the switch error flag is set. If the switch error flag is not set, the process proceeds to the process of S140. On the other hand, if the switch error flag is set, an error is displayed and the process ends. Specifically, the LED of the first display unit 15 is turned on or blinked to end the process. That is, after detecting the switch error flag, the process does not shift to the rotation process of the motor 40, and a decrease in working accuracy is suppressed.

[0124] Here, the presence or absence of the monitoring microcomputer error flag, the ground fault error flag, the sky fault error flag, the rotation direction logic error flag, the surge voltage ground and sky fault error flag, the battery voltage ground and sky fault error flag, the battery voltage logic error flag, the first temperature ground and sky fault error flag, the second temperature ground and sky fault error flag, the temperature logic error flag, and the current detection circuit error flag is not checked. This is to avoid the problem that the electric working machine 1 cannot be used in the error flag confirmation process when these error flags are erroneously set due to noise or the like generated during the rotation of the motor 40.

[0125] Subsequently, in S140, the sleep mode process is executed. Specifically, the second switch 39 is switched off to shift from the active mode to the sleep mode. Subsequently, in S150, during the sleep mode, when the user operates the trigger switch 240 from off to on, a first trigger signal indicating the on state of the trigger switch 240 is input to the main microcomputer 30, or a signal for releasing another sleep mode is input to the main microcomputer 30, and the operation of the main microcomputer 30 resumes.

[0126] In S160, a wake-up process is executed. Specifically, the second switch 39 is switched on to shift from the sleep mode to the active mode. Subsequently, in S170, the on state of the trigger switch 240 is self-checked.

[0127] Specifically, it is determined whether the second trigger operation signal input from the second trigger circuit 240b has a value indicating an on state. If it is determined that the state is on, the check of the on state of the trigger switch 240 is terminated, and the process proceeds to S180. If it is determined that the state is not on, it is determined that some abnormality has occurred in the state detection of the trigger switch 240. After setting the switch error flag, the check is terminated, and the process proceeds to S180.

[0128] Subsequently, in S180, similar to S40, the power supply permission by the monitoring microcomputer 60 is checked. When the trigger switch 240 is turned off for a predetermined period, the main microcomputer 30 shifts to the sleep mode, the power supply to the monitoring microcomputer 60 is cut off, the power supply voltage input to the monitoring microcomputer 60 decreases and enters the reset state. Accordingly, an interruption signal is input to the high-side driver 54, the third switch 55 is turned off, and the power supply to the motor driver 42 is interrupted.

[0129] In this state, even if a system error occurs in the main microcomputer 30 and the rotation process of the motor 40 is performed, since the motor driver 42 is in the interrupted state, the motor 40 does not rotate. At this time, since the monitoring microcomputer 60 is not powered on, no system error occurs, and no signal for turning on the third switch 55 is output from the monitoring microcomputer 60.

[0130] Thereafter, when the trigger switch 240 is operated to be on, the main microcomputer 30 shifts to the active mode and starts the rotation process of the motor 40. At this time, if there is some abnormality in the monitoring microcomputer 60 and no power supply signal is output to the high-side driver 54, the third switch 55 remains in the off state, and the motor 40 cannot be rotated.

[0131] Therefore, immediately after the trigger switch 240 is turned on, the main microcomputer 30 checks that the monitoring microcomputer 60 is outputting an energization signal that permits energization to the motor 40 via the high-side driver 54. That is, after the monitoring microcomputer 60 outputs an energization signal to turn on the third switch 55, the main microcomputer 30 starts the rotation process of the motor 40 in sequence.

[0132] Subsequently, in S190, similar to S130, before performing the rotation process of the motor 40, it is checked whether there is a switch error flag. If there is a switch error flag, the motor 40 may not be rotated because the working accuracy may decrease. Also, similar to S130, the presence or absence of other error flags is not checked.

[0133] Subsequently, in S200, the rotation direction signal output from the first forward / reverse circuit 260a and / or the second forward / reverse circuit 260b is read, and the rotation direction of the motor 40 is set. Subsequently, in S210, based on the first trigger signal input from the first trigger circuit 240a, it is determined whether the trigger switch 240 is on. If it is determined that the trigger switch 240 is off, the process proceeds to the process of S220.

[0134] In S220, the stop process of the motor 40 is executed, and a braking force is applied to the motor 40 for a predetermined time. Specifically, three high-side switching elements of the motor driver 42 are turned on and three low-side switching elements are turned off. Alternatively, three high-side switching elements are turned off and three low-side switching elements are turned on. Thereby, a short-circuit brake acts on the motor 40.

[0135] Subsequently, in S230, the motor 40 is de-energized, and the process returns to the process of S110. On the other hand, in S210, if it is determined that the trigger switch 240 is on, the process proceeds to the process of S260.

[0136] In S260 to S345, the state of the electric working machine 1 is checked. There are a plurality of conditions that affect the working accuracy of the electric working machine 1, and if the values of each condition exceed the allowable range, it will affect the working accuracy. Therefore, during the use of the electric tool, these conditions are repeatedly checked. When an error is detected, in order not to affect the working accuracy, the motor 40 is temporarily stopped until the error is no longer detected, that is, until the values of each condition fall within the allowable range.

[0137] Subsequently, in S260, based on the second voltage detection signal, it is determined whether the battery voltage is within the normal range, specifically, whether the battery 300 is not over-discharged. If it is determined that the battery voltage is outside the normal range (over-discharge state), the process proceeds to the process of S270. In S270, a voltage error flag is set, and the process proceeds to the process of S360.

[0138] On the other hand, in S260, if it is determined that the battery voltage is within the normal range (within the dischargeable range), the process proceeds to the process of S265. In S265, the voltage error flag is cleared, and the process proceeds to the process of S280. In S280, based on the first voltage detection signal, it is determined whether the surge voltage is within the normal range. If it is determined that the surge voltage is outside the normal range, the process proceeds to the process of S290. In S290, a surge voltage error flag is set, and the process proceeds to the process of S360.

[0139] On the other hand, in S280, if it is determined that the surge voltage is within the normal range, the process proceeds to the process of S285. In S285, the surge voltage error flag is cleared, and the process proceeds to the process of S300. In S300, based on the first temperature detection signal and / or the second temperature detection signal, it is determined whether the temperature of the switching element is within the normal range. If it is determined that the temperature of the switching element is outside the normal range (high temperature), the process proceeds to the process of S310. In S310, a temperature error flag is set, and the process proceeds to the process of S360.

[0140] On the one hand, in S300, if it is determined that the temperature of the switching element is within the normal range, the process proceeds to the process of S305. In S305, the temperature error flag is cleared, and the process proceeds to the process of S320. In S320, based on the drive current value output from the current detection circuit 43, it is determined whether the drive current value is within the normal range. If it is determined that the drive current value is outside the normal range (overcurrent), the process proceeds to the process of S330. In S330, the drive current error flag is set, and the process proceeds to the process of S360.

[0141] On the other hand, in S320, if it is determined that the drive current value is within the normal range, the process proceeds to the process of S325. In S325, the drive current error flag is cleared, and the process proceeds to the process of S340. In S340, it is determined whether a discharge permission signal is output from the signal terminal 270 to the main microcomputer 30. If it is determined that a discharge prohibition signal is output, the process proceeds to the process of S350. In S350, the discharge prohibition error flag is set, and the process proceeds to the process of S360.

[0142] On the other hand, in S340, if it is determined that a discharge permission signal is output, the process proceeds to the process of S345. In S345, the discharge prohibition error flag is cleared, and the process proceeds to the process of S240.

[0143] In S240, the second trigger operation signal output from the second trigger circuit 240b, that is, the speed command value of the rotational speed of the motor 40, is read. Subsequently, in S250, a control signal corresponding to the read speed command value is generated and output to the motor driver 42. The control signal is a pulse width modulation (hereinafter, PWM) signal, and according to the speed command value, the ratio of the on-time to the off-time of the PWM signal (hereinafter, duty) is set. Note that the duty is limited according to the upper limit value of the rotational speed. Subsequently, the process returns to the process of S210.

[0144] In S360, the motor 40 is de-energized. Subsequently, in S370, the LEDs of the first display unit 15 are turned on or blinked to display an error. At this time, the blinking pattern may be changed according to the type of error flag that is set. Also, the error information may be stored in the memory 30b.

[0145] <2-2. Monitoring Microcontroller Processing> Next, the monitoring microcontroller processing executed by the monitoring microcontroller 60 will be described with reference to FIG. 4. The monitoring microcontroller 60 starts this processing from when the main microcontroller 30 is set to the active mode or when the reset state of the monitoring microcontroller 60 is released.

[0146] First, in S400, initialization is executed. Specifically, the monitoring microcontroller 60 initializes the RAM and / or registers. Subsequently, in S410, energization of the motor 40 is permitted. Specifically, a power-on signal for turning on the third switch 55 is output to the high-side driver 54 to make the third switch 55 in an on-enabled state.

[0147] Subsequently, in S420, the timer interrupt is started. Subsequently, in S430, the Hall IC interrupt is started. The Hall IC interrupt input from the Hall IC constituting the position sensor 41 occurs in response to the output of a position signal from any of the three Hall sensors. When the Hall IC interrupt occurs, the monitoring microcontroller 60 executes the subroutine of the Hall IC interrupt processing shown in FIG. 5.

[0148] First, in S600, the current timer value is stored in the memory 60b as the current time. This current time is used to calculate the rotational speed of the motor 40. Subsequently, in S610, the timer value is cleared. Thereby, the addition of the timer value restarts from 0. That is, since the timer value stored in the memory 60b as the current time indicates the time from when the previous Hall IC interrupt occurred to when the current Hall IC interrupt occurs, it becomes the time required for the motor 40 to rotate by a predetermined angle.

[0149] Subsequently, in S620, the interrupt source Hall IC and the direction of its signal are stored in the memory 60b as the current specific values. That is, the output source of the current position signal (i.e., any one of U-phase rising, U-phase falling, V-phase rising, V-phase falling, W-phase rising, W-phase falling) is stored in the memory 60b as the current specific value.

[0150] Subsequently, in S630, a Hall IC flag indicating that a Hall IC interrupt has occurred is set. Therefore, while the motor 40 is continuously rotating, the position signal of the position sensor 41 is output, and each time a Hall IC interrupt occurs, the timer value is cleared. On the other hand, when the rotation of the motor 40 stops, the position signal is not output, the timer value is not cleared, and when the timer value reaches the set value, that is, when a predetermined time has elapsed, a timer interrupt occurs.

[0151] If the monitoring microcomputer 60 determines that the motor 40 has stopped when the timer value is not cleared until 1 second has elapsed since the addition of the timer value started from 0, a timer interrupt is generated. When a timer interrupt occurs, the monitoring microcomputer 60 executes the subroutine of the timer interrupt process shown in FIG. 6.

[0152] First, in S700, the standby counter N is set to 1. Two or more Hall IC interrupts are required to calculate the rotation speed, rotational acceleration, rotational deceleration, and rotation direction. The standby counter N is a flag indicating whether there have been two or more Hall IC interrupts. A standby counter N value of 1 indicates that there has been one or fewer Hall IC interrupts, and a value of 0 for the standby counter N indicates that there have been two or more Hall IC interrupts.

[0153] Subsequently, in S710, the timer value is cleared and the addition of the timer value is restarted from 0. Subsequently, in S720, the timer interrupt is restarted. Specifically, when the timer value is not cleared within 1 second, a timer interrupt is generated.

[0154] Next, in S450, the WDT65 is started. Subsequently, in S460 to S565, the monitoring process of the motor 40 is started. In the present embodiment, first, in S460, the first rotation direction signal output from the first forward / reverse circuit 260a is read, and the rotation instruction direction of the motor 40 is acquired.

[0155] Subsequently, in S470, the rotation instruction direction acquired in S460 is stored in the memory 60b. Subsequently, in S480, an error flag check process is executed. In the processes described later, when the rotation speed, rotation acceleration, rotation deceleration, and rotation direction of the motor 40 are different from the allowable values, the corresponding error flag is set. In S480, it is determined whether any error flag is set, and corresponding processing is executed according to whether the error flag is set. The details of the error flag check process will be described later.

[0156] Subsequently, in S490, the WDT65 is cleared, and the addition of the timer value of the WDT65 is restarted from 0. Thereafter, when it is determined that the motor 40 has malfunctioned by monitoring the rotation-related values of the motor 40, an error flag is set in the error flag check process described later, and the process returns to the process of S480.

[0157] In the present embodiment, as the rotation-related values, the rotation speed, rotation acceleration, rotation deceleration, and rotation direction are acquired. The monitoring microcomputer 60 is configured such that the monitoring process makes one round within a specified predetermined time Ta. If the monitoring process does not make one round within the predetermined time Ta and the timer value of the WDT65 is not cleared before exceeding the predetermined time Ta, the WDT resets the monitoring microcomputer. The details of the predetermined time Ta will be described later.

[0158] Subsequently, in S500, based on the first trigger signal input from the first trigger circuit 240a, it is determined whether the trigger switch 240 is on. If it is determined that the trigger switch 240 is off, the process proceeds to the process of S510.

[0159] In S510, fault diagnosis processing is performed on the input line of the first trigger signal output by the first trigger circuit 240a. Details of the fault diagnosis processing will be described later. After the processing of S510, the process returns to the processing of S460.

[0160] On the other hand, in S500, if it is determined that the trigger switch 240 is on, the process proceeds to the processing of S530. In S530, rotation speed monitoring processing of the motor 40 is performed. And when the rotation speed of the motor 40 exceeds the upper limit value, a rotation speed excess flag is set. Details of the rotation speed monitoring processing will be described later.

[0161] Subsequently, in S540, rotation acceleration / deceleration monitoring processing is performed. And when the rotational acceleration is different from the acceleration allowable value, a rapid acceleration flag is set. Also, when the rotational deceleration is different from the deceleration allowable value, a rapid deceleration flag is set. Details of the rotation acceleration / deceleration monitoring processing will be described later.

[0162] Subsequently, in S550, rotation direction monitoring processing is performed. And when the rotation direction of the motor 40 is different from the rotation instruction direction stored in the memory 60b, a rotation mismatch flag is set. Details of the rotation direction monitoring processing will be described later.

[0163] Subsequently, in S560, the value of the standby counter N is updated to the value obtained by subtracting "1". Here, if the value of the standby counter N was 0, it remains 0, and the process proceeds to the processing of S565. Subsequently, in S565, the Hall IC flag is cleared, and the process returns to the processing of S480.

[0164] <2-2-1. Trigger Switch Diagnosis Processing> Next, the fault diagnosis processing of the first trigger signal executed by the monitoring microcomputer 60 in S510 will be described with reference to the subroutine of FIG. 7.

[0165] When a failure occurs where the on state of the trigger switch 240 cannot be detected, the monitoring microcomputer 60 becomes unable to make a malfunction determination based on at least the rotational deceleration rate during the operation monitoring of the motor 40, which may affect the working accuracy. Here, it is determined whether the rotational deceleration rate of the motor 40 can be monitored.

[0166] In S15, it is determined whether the drive current value is 0. Here, when the trigger switch 240 is off, the main microcomputer 30 outputs a control signal to turn off the excitation of the motor 40 to the motor driver 42, and the drive current value becomes 0. That is, when the trigger switch 240 is off, the drive current value becomes 0.

[0167] From this condition, when the monitoring microcomputer 60 detects that the drive current value is not 0 while detecting that the trigger switch 240 is off, it can be diagnosed that a failure has occurred where the on state of the trigger switch 240 cannot be detected.

[0168] Also, when the monitoring microcomputer 60 has a failure such that it always detects the drive current value as 0, the above failure diagnosis cannot detect a failure of the trigger switch 240. Therefore, in the rotational acceleration / deceleration monitoring described later, a failure diagnosis is performed to determine whether there is a failure where the drive current value is always detected as 0.

[0169] In S15, if it is determined that the drive current value is 0, the process proceeds to the process of S16, and if it is determined that the drive current value is not 0, the process proceeds to the process of S25. In S16, it is determined whether a current detection error flag described later is set. If it is determined that the current detection error flag is set, the process proceeds to the process of S25 and the use of the electric working machine 1 is prohibited. If it is determined that the current detection error flag is not set, this subroutine is terminated and the process returns to the process of S460.

[0170] In S25, energization of the motor 40 is prohibited. Subsequently, in S35, the timer value of the WDT 65 is cleared. Thereafter, the process returns to the process of S25, and the processes of S25 and S35 are repeatedly executed. That is, when a failure in which the turning on of the trigger switch 240 cannot be detected, that is, a failure in the signal line L3 is detected, the rotational deceleration rate of the motor 40 cannot be monitored, and there is a possibility that the working accuracy may decrease. Therefore, the power supply to the motor 40 is continuously cut off, and the use of the electric working machine 1 is prohibited.

[0171] <2-2-2. Speed monitoring process> Next, the rotational speed monitoring process executed by the monitoring microcomputer 60 in S530 will be described with reference to the subroutine of FIG. 8.

[0172] First, in S105, it is determined whether the value of the standby counter N is 0. That is, it is determined whether the hall IC interrupt has occurred two or more times. If it is determined in S105 that the value of the standby counter N is different from 0, this subroutine is terminated and the process proceeds to the process of S540.

[0173] On the other hand, if it is determined in S105 that the value of the standby counter N is 0, the process proceeds to the process of S115. In S115, the current time stored in S600 is read from the memory 60b.

[0174] Next, in S125, it is determined whether the current time is equal to or greater than a predetermined value. The current time corresponds to the interval between consecutive Hall IC interrupts. That is, the current time corresponds to the time it takes for the motor 40 to rotate through an electrical angle of 120°. Therefore, if the current time is equal to or greater than the predetermined value, the rotation speed of the motor 40 is equal to or less than the speed tolerance value. If the current time is less than the predetermined value, the rotation speed of the motor 40 is greater than the speed tolerance value. The speed tolerance value is a value up to the limit speed of the tip tool connected to the load side shaft 40a of the motor 40, or is set for the system in order to increase the durability of the tool body or to increase the sensitivity value such as reducing the noise of the tool body, or is a value up to the maximum value of the rotation speed of the motor 40 that is set for the system or is set in the system. That is, the speed tolerance value is a value within the range that the rotation speed of the motor 40 can take.

[0175] In S125, if it is determined that the current time is equal to or greater than the predetermined value, this subroutine is terminated and the process proceeds to S540. On the other hand, in S125, if it is determined that the current time is less than the predetermined value, the process proceeds to S135.

[0176] An excess of the rotation speed of the motor 40 may occur when the duty of the PWM signal output to the motor driver 42 calculated based on the speed command value becomes an incorrect duty due to a system error of the main microcomputer 30 or due to noise, and becomes larger than the original value. And if the operation continues with the rotation speed of the motor 40 exceeding, there is a possibility that the operation accuracy will decrease. Therefore, in S135, a rotation speed excess flag, which is a type of error flag, is set. By setting the rotation speed excess flag, the power supply to the motor 40 is cut off in subsequent processing. After the process of S135, this subroutine is terminated and the process proceeds to S540.

[0177] <2-2-3. Rotation Acceleration / Deceleration Monitoring Process> Next, the rotation acceleration / deceleration monitoring process executed by the monitoring microcomputer 60 in S540 will be described with reference to the subroutine in FIG. 9.

[0178] First, in S205, the current time stored in S600 is read from the memory 60b. Subsequently, in S215, it is determined whether the value of the standby counter N is 0. If it is determined that the value of the standby counter N is not 0, the processes of S225 to S295 are skipped and the process proceeds to S305.

[0179] On the other hand, in S215, if it is determined that the value of the standby counter N is 0, the process proceeds to S225. In S225, the previous time is read from the memory 60b. The previous time corresponds to the timer value stored in the memory 60b at that time, that is, the interval (time) between the occurrences of the hall IC interrupts, which is one before the current time.

[0180] Subsequently, in S235, the rotational acceleration and the rotational deceleration are calculated. Specifically, the previous time is subtracted from the current time to calculate a difference value. If the current time is greater than the previous time, the rotational speed is decelerating. Therefore, when the difference value is positive, the difference value is taken as the rotational deceleration value and the rotational acceleration is set to 0. If the current time is less than the previous time, the rotational speed is accelerating. Therefore, when the difference value is negative, the absolute value of the difference value is taken as the rotational acceleration and the rotational deceleration value is set to 0.

[0181] Subsequently, in S245, it is determined whether the calculated rotational acceleration matches the acceleration allowable value. The acceleration allowable value is a value in the range from 0 to the upper limit value of the rotational acceleration. If the calculated rotational acceleration matches the acceleration allowable value, the process proceeds to S256. If the calculated rotational acceleration does not match the acceleration allowable value, that is, if the calculated rotational acceleration exceeds the upper limit value of the rotational acceleration, the process proceeds to S255.

[0182] When the rotational acceleration value of the rotational speed exceeds the upper limit value, a relatively large reaction torque is generated. When a relatively large reaction torque is generated, the user is swung around by the power working machine 1. Therefore, when rapid acceleration of the motor 40 occurs, the working accuracy may decrease. Therefore, in S255, an abrupt acceleration flag, which is a type of error flag, is set and the process proceeds to S305. By setting the abrupt acceleration flag, the power supply to the motor 40 is cut off in subsequent processing.

[0183] The abrupt acceleration of the motor 40 occurs when a system error occurs in the main microcomputer 30 or when the on-duty of the PWM signal output to the motor driver 42 suddenly changes from a small value to a large value due to noise.

[0184] Since the monitoring microcomputer 60 detects this abrupt acceleration and immediately cuts off the power supply to the motor 40, the duration of the reaction torque is short. However, this is not the case when a system error occurs in both the main microcomputer 30 and the monitoring microcomputer 60.

[0185] Here, when the amount by which the power working machine 1 is swung around by the reaction torque generated by abrupt acceleration (that is, the angle by which it is swung around by the reaction torque around the user's wrist) exceeds a predetermined angle, it becomes difficult for the user to hold the power working machine 1. Therefore, if the power supply to the motor 40 can be cut off before a predetermined time Ta elapses from the time when abrupt acceleration is detected, the user can hold the power working machine 1 even if a reaction torque occurs.

[0186] Therefore, the predetermined time Ta (that is, the count-up time of the WDT) is set so that the amount of swing of the power working machine 1 does not exceed the predetermined angle. If set in this way, even if an abrupt acceleration occurs due to a system error in the main microcomputer 30 and a system error also occurs in the monitoring microcomputer 60, making it impossible to monitor the motor 40, before the amount by which the power working machine 1 is swung around exceeds the predetermined angle, the monitoring microcomputer 60 is reset by the WDT and the power supply to the motor 40 is cut off, so the user can hold the power working machine 1.

[0187] The predetermined time Ta (that is, the time from when a system error occurs in the monitoring microcomputer until the power supply to the motor 40 is cut off) corresponds to the time required for the load-side shaft 40a to reach the maximum rotational speed from the stopped state with a constant rotational acceleration to rotate by a predetermined angle. Further, it corresponds to the time required for the load-side shaft 40a to rotate by twice the predetermined angle when it is rotating at a constant speed at the maximum rotational speed.

[0188] Also, in the present embodiment, the predetermined angle is set to 90°. The movable range of a human wrist is approximately 90°. Therefore, when a relatively large reaction torque is generated, by cutting off the power supply to the motor 40 before the load-side shaft 40a rotates 90°, the user can continue to hold the electric working machine 1.

[0189] In S256, it is determined whether or not it is a failure state in which the monitoring microcomputer 60 always detects the drive current value as 0. When the motor 40 is in an accelerating state, energy for acceleration is supplied to the motor 40, so a drive current always flows. The determination of a failure in which the drive current is always detected as 0 is made by checking whether or not this drive current is 0.

[0190] That is, if it can be confirmed at the timing of S256 when the rotational acceleration of the motor 40 is detected that the drive current value is greater than 0, it can be said that the monitoring microcomputer 60 is not malfunctioning so as to always read the input drive current value as 0. Consequently, it can be said that the failure diagnosis in S510 is completed.

[0191] Specifically, in S256, it is determined whether or not the rotational acceleration calculated in S235 is greater than 0, that is, whether or not it is accelerating. If the calculated rotational acceleration is 0 or less, the process proceeds to the process of S265. If the calculated rotational acceleration is greater than 0, the process proceeds to the process of S257.

[0192] In S257, based on the drive current value output from the current detection circuit 43, it is determined whether or not the drive current value is greater than 0. If the detected drive current value is 0, the process proceeds to S258. Subsequently, in S258, a current detection error flag, which is one type of error flag, is set, and the process proceeds to S305. If the detected drive current value is greater than 0, the process proceeds to the process of S265.

[0193] Here, the rotational acceleration calculated in S235 was compared with 0, but considering the output tolerance of the current detection circuit 43, it may be compared with a value greater than 0. Subsequently, in S265, it is determined whether the calculated rotational deceleration matches the deceleration tolerance value. The deceleration tolerance value is a value in the range from 0 to the upper limit value of the rotational deceleration. Similar to the rotational acceleration, if the calculated rotational deceleration exceeds the upper limit value, a relatively large reaction torque occurs. If the calculated rotational deceleration matches the deceleration tolerance value, the process proceeds to the process of S305. If the calculated rotational deceleration does not match the deceleration tolerance value, that is, if the calculated rotational deceleration exceeds the upper limit value of the rotational deceleration, the process proceeds to the process of S275.

[0194] Subsequently, in S275, it is determined whether the trigger switch 240 is on. If the trigger switch 240 is off, the motor 40 is decelerating because the user has turned off the trigger switch 240. Therefore, in this case, it is different from a system error of the main microcomputer 30. Thus, if it is determined that the trigger switch 240 is off, the error flag is not set, and the process proceeds to the process of S305.

[0195] On the other hand, in S275, if it is determined that the trigger switch 240 is on, the process proceeds to the process of S285. In S285, it is determined whether the drive current value is 0. If the trigger switch 240 is on and the drive current value is not 0, for example, the motor 40 may be locked and decelerating rapidly. For example, when the saw blade 230 hits a hard object, the saw blade 230 is fixed, the motor 40 is locked, and decelerates rapidly. In this case, since more drive current flows in an attempt to move the rapidly decelerating motor 40, the drive current does not become 0. Therefore, when the trigger switch 240 is on and the drive current is not 0, it is different from a system error of the main microcomputer 30. Therefore, if it is determined that the drive current is not 0, the error flag is not set, and the process proceeds to the process of S305.

[0196] On the other hand, in S285, if it is determined that the drive current is 0, the process proceeds to the process of S295. In S295, since an unintended rapid deceleration of the motor 40 has occurred (that is, when the trigger switch 240 is turned on, for example, during work, a motor brake suddenly occurs due to a system error of the main microcomputer 30 and is in a state of rapid deceleration), a rapid deceleration flag, which is a type of error flag, is set.

[0197] Subsequently, in S305, the current time is stored in the memory 60b as the previous time, this subroutine is terminated, and the process proceeds to the process of S550. <2-2-4. Rotation Direction Monitoring Process> Next, the rotation direction monitoring process executed by the monitoring microcomputer 60 in S550 will be described with reference to the subroutine of FIG. 10.

[0198] First, in S405, the current specific value stored in S620 is read from the memory 60b. Subsequently, in S415, it is determined whether the value of the standby counter N is 0. If it is determined in S415 that the value of the standby counter N is not 0, the process proceeds to the process of S475.

[0199] On the other hand, if it is determined in S415 that the value of the standby counter N is 0, the process proceeds to the process of S425. In S425, the previous specific value is read from the memory 60b. The previous specific value corresponds to the source of the interruption of the Hall IC that constitutes the position sensor 41 at the position immediately before the current specific value.

[0200] Subsequently, in S435, the rotation direction of the motor 40 is calculated from the current specific value and the previous specific value. Subsequently, in S445, the rotation instruction direction stored in S470 is read from the memory 60b.

[0201] Subsequently, in S455, it is determined whether the rotation direction calculated in S435 matches the rotation instruction direction read in S445. If it is determined that the rotation directions match, the process proceeds to S475. In S475, the current specific value is stored in the memory 60b as the previous specific value.

[0202] On the other hand, if it is determined in S455 that the rotation directions do not match, the process proceeds to the process of S465. The mismatch in the rotation direction may be caused by a system error of the main microcomputer 30. If the operation continues with the motor 40 rotating in a rotation direction different from the instruction, the operation accuracy may decrease. Therefore, in S465, a rotation direction mismatch flag, which is a type of error flag, is set. Thereafter, the subroutine is terminated and the process proceeds to the process of S560.

[0203] <2-2-5. Error flag check process> Next, the error flag check process executed by the monitoring microcomputer 60 in S480 will be described with reference to the subroutine of FIG. 11.

[0204] First, in S800, it is determined whether the speed excess flag is set. If it is determined that the rotation speed excess flag is set, the process proceeds to the process of S840, and if it is determined that the rotation speed excess flag is not set, the process proceeds to the process of S810.

[0205] In S810, it is determined whether the rapid acceleration flag is set. If it is determined that the rapid acceleration flag is set, the process proceeds to the process of S840. If it is determined that the rapid acceleration flag is not set, the process proceeds to the process of S820.

[0206] In S820, it is determined whether the rapid deceleration flag is set. If it is determined that the rapid deceleration flag is set, the process proceeds to the process of S840. If it is determined that the rapid deceleration flag is not set, the process proceeds to the process of S830.

[0207] In S830, it is determined whether the rotation direction mismatch flag is set. If it is determined that the rotation direction mismatch flag is set, the process proceeds to the process of S840. If it is determined that the rotation direction mismatch flag is not set, this subroutine is terminated and the process proceeds to the process of S490.

[0208] In S840, it is determined whether the output completed flag of the reset signal is set. If it is determined that the output completed flag is set, in order to prevent the reset signal output to the main microcomputer 30 from being continuously output multiple times, the processes of S843 to S870 are skipped and the process proceeds to the process of S880. If it is determined that the output completed flag is not set, the process proceeds to the process of S843.

[0209] In S843, it is determined whether the rapid deceleration flag is set. If it is determined that the rapid deceleration flag is set, that is, since the motor 40 is rapidly decelerating, when giving priority to the reset output to the main microcomputer 30 over the power cut-off to the motor 40, the process proceeds to the process of S845.

[0210] If it is determined that the rapid deceleration flag is not set, that is, when not giving priority to the reset output to the main microcomputer 30, the process proceeds to the process of S851. In S845, in order to cause the main microcomputer 30 to recover from a system error, a reset signal is output to the main microcomputer 30 for a predetermined time. As a result, the main microcomputer 30 is initialized and recovers from the system error. Here, the monitoring microcomputer 60 outputs a reset signal to the main microcomputer 30, and the main microcomputer 30 is reset. Since the main microcomputer 30 during reset cannot output a signal to turn on the second switch 39, the power supply path to the monitoring microcomputer 60 is cut off, and the power supply voltage of the monitoring microcomputer 60 begins to decrease.

[0211] That is, if the output time of the reset signal output from the monitoring microcomputer 60 is long, the output voltage of the second switch 39 decreases and falls below the lower limit voltage of the second guarantee circuit 36b of the voltage guarantee circuit 36, and the monitoring microcomputer 60 is also reset.

[0212] Therefore, the reset time output by the monitoring microcomputer 60 is set to be longer than the time during which the main microcomputer 30 can be reset and within the time from when the second switch 39 is turned off until the output voltage of the second switch 39 reaches the lower limit voltage of the second guarantee circuit 36b.

[0213] Subsequently, in S847, a cutoff signal for turning off the third switch 55 is output to the high-side driver 54 to prohibit energization of the motor 40, and the process proceeds to the process of S870. When the rapid deceleration flag is set, even if the energization of the motor 40 is cut off, the reaction torque due to the rotational deceleration continues to occur. Therefore, when a malfunction is detected based on the rotational deceleration, by executing the output of the reset signal with priority over the cutoff of the energization of the motor 40, the reaction torque disappears earlier. In S851, a cutoff signal for turning off the third switch 55 is output to the high-side driver 54 to prohibit energization of the motor 40, and the process proceeds to the process of S861.

[0214] Subsequently, in S861, in order to cause the main microcomputer 30 to recover from a system error, a reset signal is output to the main microcomputer 30 for a predetermined time. As a result, the main microcomputer 30 initializes, recovers from the system error, and proceeds to the process of S870.

[0215] Subsequently, in S870, in order to avoid outputting a multiple reset signal to the main microcomputer 30, an output flag is set. Subsequently, in S880, it is determined whether the trigger switch 240 is off based on the trigger signal input from the first trigger circuit 240a. If it is determined that the trigger switch 240 is on, this subroutine is terminated and the process proceeds to S490.

[0216] On the other hand, in S880, if it is determined that the trigger switch 240 is off, the process proceeds to the process of S890. Subsequently, in S890, an energization signal for turning on the third switch 55 is output to the high-side driver 54 to permit energization of the motor 40. Since the trigger switch 240 is off, even if the monitoring microcomputer 60 permits energization of the motor 40, a cutoff signal is input from the off trigger switch 240 to the high-side driver 54, so the third switch 55 remains off and the motor 40 does not suddenly start rotating. Therefore, an energization signal for turning on the third switch 55 at this timing is output to the high-side driver 54. As a result, the trigger switch 240 is operated to be on, all signals input to the high-side driver 54 become energization signals, and when the main microcomputer 30 detects the turning on of the trigger switch 240 in S210 and outputs a control signal to the motor driver 42 in S250, the motor 40 immediately starts rotating.

[0217] Subsequently, in S900, the output flag is cleared. Subsequently, in S910, each error flag is cleared. That is, the rotation speed excess flag, the rapid acceleration flag, the rapid deceleration flag, and the rotation direction mismatch flag are cleared. Then, this subroutine is terminated and the process proceeds to S490.

[0218] Here, assume that during the operation using the electric working machine 1, a system error occurs simultaneously in the main microcomputer 30 and the monitoring microcomputer 60, resulting in a malfunction of the motor. In this case, first, the WDT of the monitoring microcomputer 60 activates, the monitoring microcomputer 60 resets and restarts, and immediately resumes the monitoring operation of the motor 40, thereby suppressing a decrease in work accuracy.

[0219] <3. Effects> According to the first embodiment described above, the following effects can be obtained. (1) When the monitoring microcomputer 60 determines that the motor 40 has malfunctioned, it outputs a reset signal to the main microcomputer 30 for a predetermined time and stops the rotation control process for the motor 40. As a result, the main microcomputer 30 is initialized, and the rotation control process in the main microcomputer 30 is not resumed until the trigger switch 240 is turned off and then turned on again. Therefore, after a system error occurs in the main microcomputer 30 and the motor stops, the motor does not suddenly restart without a trigger operation by the user, so it is possible to suppress a decrease in work accuracy and work efficiency due to the sudden generation of a large reaction torque.

[0220] (2) When at least one of the rotation speed, rotation acceleration, rotation deceleration, and rotation direction of the motor 40 is different from the value allowed in normal rotation control, it can be determined that the motor 40 has malfunctioned.

[0221] (3) Set a predetermined time Ta so that the amount by which the electric working machine 1 is swung by the reaction torque from the time when the reaction torque occurs is within the movable range of the user's wrist. Therefore, by cutting off the power supply to the motor 40 and stopping the motor 40 until the predetermined time Ta elapses from the time when the malfunction is detected, the state in which the user holds the electric working machine 1 can be maintained.

[0222] (4) By setting the predetermined time Ta to the maximum value, preferably, the amount by which the electric working machine 1 is swung by the reaction torque can be kept within the movable range of the user's wrist. (5) By setting the timer value of the WDT of the monitoring microcontroller 60 within a predetermined time Ta, even if a system error occurs in the monitoring microcontroller 60, the amount by which the electric working machine 1 is swung by the reaction torque can be suitably kept within the movable range of the user's wrist.

[0223] (6) Since the movable range of the wrist is about 90°, by setting a predetermined angle to 90°, the user can maintain the holding of the electric working machine 1. (7) By executing the monitoring process only while at least the trigger switch 240 is on, that is, while the motor 40 is energized, it is possible to detect a malfunction of the motor 40 during the rotation control of the motor 40 and reset the main microcontroller 30, pause the monitoring process while the motor 40 is not under rotation control, and reduce the power consumption accordingly.

[0224] (8) When the rapid deceleration flag is set, even if the power supply to the motor 40 is cut off, the reaction torque due to the rapid deceleration continues to occur. Therefore, when the rapid deceleration flag is set, by executing the output of the reset signal prior to cutting off the power supply to the motor 40, it is possible to quickly eliminate the reaction torque due to the rapid deceleration of the motor 40.

[0225] (9) When the trigger switch 240 is on and the value of the drive current is 0, by obtaining the rotational deceleration of the motor 40, it is possible to obtain the rotational deceleration caused by a system error of the main microcontroller 30 instead of the rotational deceleration caused by the handling of the electric working machine 1 by the user.

[0226] (10) After cutting off the power supply to the motor 40, in response to detecting that the trigger switch 240 is off, by turning on the third switch 55, when the trigger switch 240 is turned on again, the main microcontroller 30 can restart the motor 40 at high speed.

[0227] When the main microcomputer 30 attempts to start driving the motor 40, if the monitoring microcomputer error flag is set and a cutoff signal for turning off the third switch 55 is output, the stop of the motor 40 continues. On the other hand, after an energization signal for turning on the third switch 55 is output, by energizing the motor driver 42, it is possible to suppress the inability to start the rotation of the motor 40 when the main microcomputer 30 attempts to start the rotation of the motor 40.

[0228] (Second Embodiment) Since the basic configuration of the second embodiment is the same as that of the first embodiment, the differences will be described below. Note that the same reference numerals as those in the first embodiment indicate the same configurations, and reference is made to the preceding description.

[0229] <1. Configuration> FIG. 12 shows the electrical configuration of the electric working machine 1 according to the second embodiment. In the second embodiment, it is different from the first embodiment in that, in addition to the main microcomputer 30, a monitoring microcomputer 60 controls the on / off of the second switch 39.

[0230] When the main microcomputer 30 wakes up, it clears the WDT in the register. Then, the main microcomputer 30 turns off the second switch 39 and shifts to the sleep state. Here, when the main microcomputer 30 is configured to be automatically reset by the WDT when an error occurs in the main microcomputer 30, the sleep current of the main microcomputer 30 cannot be reduced in the standby mode. Since the WDT detection time (clear time) Ta is short, even if the main microcomputer 30 enters the sleep mode with low power consumption, it immediately wakes up (returns to the normal mode with high power consumption), and it is necessary to execute the clearing of the WDT, so the power consumption cannot be reduced. Therefore, in order to reduce the power consumption, in addition to the main microcomputer 30, a monitoring microcomputer 60 with a WDT is required.

[0231] Also, in this embodiment, when a specific rotation error occurs due to a malfunction of the main microcomputer 30, the monitoring microcomputer 60 outputs a restart permission to the main microcomputer 30. The specific rotation error is any one of sudden acceleration, sudden deceleration, and speed overshoot. The time from when a rotation error occurs due to a malfunction of the main microcomputer 30 until the main microcomputer 30 receives a reset signal and restarts is very short. Therefore, immediately after the main microcomputer 30 restarts, the motor 40 is coasting at the same rotational speed as when the rotation error was detected. Also, when restarted, the main microcomputer 30 has returned to normal operation.

[0232] Even if the main microcomputer 30 that has returned to normal operation immediately resumes energization of the coasting motor 40 after an error such as sudden acceleration, sudden deceleration, or speed overshoot occurs, no large reaction torque is generated. By immediately resuming energization of the motor 40, it may be possible to resume energization before the motor 40 completely stops. Therefore, it is possible to minimize the decrease in work efficiency associated with the occurrence of a system error in the main microcomputer 30.

[0233] On the other hand, when the rotation error is an error in which the actual rotation direction of the motor 40 is different from the set direction, when the main microcomputer 30 restarts and resumes energization of the motor 40 while coasting in the direction opposite to the set direction, the rotation direction changes to the set direction. As a result, a large reaction torque is generated and the work accuracy decreases. Therefore, when a rotation error other than the specific rotation error occurs, the monitoring microcomputer 60 does not output a restart permission to the main microcomputer 30.

[0234] <2. Processing> <2-1. Main Microcomputer Processing> A part of the rotation control process executed by the main microcomputer 30 according to the second embodiment, instead of a part of the rotation control process shown in FIG. 3A, will be described with reference to the flowcharts of FIGS. 13A and 13B.

[0235] In the second embodiment, compared with the first embodiment, between the processes of S30 and S40, the processes of S31, S32, S33, S34, and S35 are additionally executed.

[0236] In S30, when it is determined that the trigger switch 240 is off, the process proceeds to S35, and the normal startup process of the motor 40 is executed. On the other hand, when it is determined that the trigger switch 240 is on, the process proceeds to S31, and it is determined whether the motor 40 can be restarted with the trigger switch 240 on, that is, whether the power supply to the motor 40 can be resumed. If no large reaction torque is generated when the motor 40 is restarted, the motor 40 can be restarted with the trigger switch 240 on. That is, the special startup process of the motor 40 can be executed. If a large reaction torque is generated when the motor 40 is restarted, the motor 40 cannot be restarted until the trigger switch 240 is once switched off. That is, only the normal startup process of the motor 40 can be performed.

[0237] In S31, it is determined whether permission to restart is received from the monitoring microcomputer 60. When it is determined that permission to restart is received, the process proceeds to S32, and when it is determined that permission to restart is not received, the process proceeds to S35.

[0238] In S32, it is determined whether the current rotational speed of the motor 40 is greater than a preset predetermined value. The main microcomputer 30 calculates the rotational speed based on the position signal output from the position sensor 41. When the motor 40 is coasting at a rotational speed below the predetermined value, the motor 40 is substantially stopped. When the power supply to the motor 40 is resumed in a state where the motor 40 is substantially stopped, the rotational speed of the motor 40 suddenly increases, and a large reaction torque is generated. Therefore, when the rotational speed is greater than the predetermined value, the process proceeds to S33, and the determination as to whether the motor 40 can be restarted with the trigger switch 240 on continues. When the rotational speed is below the predetermined value, the process proceeds to S35, and the normal startup process of the motor 40 is executed.

[0239] In S33, the rotation direction signal is read, and the rotation direction (i.e., the set direction) indicated by the rotation direction signal is obtained. In S34, it is determined whether the set direction obtained in S33 matches the actual rotation direction of the motor 40. If the set direction and the actual rotation direction match, even if the power supply to the motor 40 is restarted, the generation of a large reaction torque can be avoided. Therefore, in this case, the process proceeds to the process of S200. Thereafter, in S200 to S370, the activation process of the motor 40 is executed while the trigger switch 240 remains on.

[0240] On the other hand, if the set direction and the actual rotation direction do not match, the process proceeds to the process of S35. In S35, it is determined whether the trigger switch 240 is off. If it is determined that the trigger switch 240 is on, the process of S35 is repeatedly executed until it is determined that the trigger switch 240 is off. If it is determined that the trigger switch 240 is off, the process proceeds to the process of S40. Thereafter, in S40 to S370, a self-check is performed and the normal activation process of the motor 40 is executed.

[0241] <2-2. Error flag check process> Regarding the error flag check process that the monitoring microcomputer 60 according to the second embodiment executes instead of the error flag check process in S480 in the monitoring microcomputer process, it will be described with reference to FIGS. 14A and 14B.

[0242] In the second embodiment, compared with the first embodiment, before the process of S800, the processes of S770 to S790 are additionally executed. Also, between the processes of S820 and S830, the processes of S821, S822, S824, S826, and S828 are additionally executed. Also, instead of the processes of S843, S845, S847, S851, S861, and S910, the processes of S850, S860, S870, S873, and S913 are executed.

[0243] In the S770, it is determined whether or not the restart permission is being output to the main microcomputer 30. If it is determined that the restart permission is being output, the process proceeds to the S780 process. If it is determined that the restart permission is not being output, the process proceeds to the S800 process.

[0244] In the S780, it is determined whether or not the trigger switch 240 is off. If it is determined that the trigger switch 240 is on, the output of the restart permission is continued and the process proceeds to the S800 process. If it is determined that the trigger switch 240 is off, the process proceeds to the S790 process and the output of the restart permission to the main microcomputer 30 is stopped.

[0245] Normally, the monitoring microcomputer 60 does not permit the restart of the motor 40 when the trigger switch 240 is on. When the monitoring microcomputer 60 permits the restart of the motor 40 under specific conditions when the trigger switch 240 is on, it outputs the restart permission to the main microcomputer 30. When the trigger switch 240 is turned off, since there is no need to output the restart permission to the main microcomputer 30, the output of the restart permission is stopped. The monitoring microcomputer 60 stops the output of the reset signal in the process described later and stops the output of the restart permission after the off state of the trigger switch 240 is detected. Note that in the present embodiment, the restart permission corresponds to an example of the specific error signal of the present disclosure.

[0246] Subsequently, the processes of S800 to S820 are executed. If an affirmative determination is made in any of the determinations of S800 to S820, the process proceeds to the S821 process. That is, if the rotation error is any one of rapid acceleration, rapid deceleration, and speed excess, the process proceeds to the S821 process.

[0247] In the S821, in order to return the main microcomputer 30 from the system error, a reset signal is output to the main microcomputer 30. This reset signal is a pulse signal. The monitoring microcomputer 60 stops the output of the reset signal after outputting the reset signal for one pulse.

[0248] Subsequently, in the S822, the output of the restart permission to the main microcomputer 30 is started. Subsequently, in S824, the rotation speed excess flag is cleared. Subsequently, in S826, the rapid acceleration flag is cleared. Subsequently, in S828, the rapid deceleration flag is cleared.

[0249] Subsequently, the process of S830 is executed. If there is a rotation direction mismatch flag, that is, if a rotation error other than a specific rotation error occurs, the process proceeds to the process of S840. In S840, it is determined whether the output completed flag of the reset signal is set. If it is determined that the output completed flag is set, the process proceeds to the process of S880. If it is determined that the output completed flag is not set, the process proceeds to the process of S850.

[0250] In S850, a reset signal is output to the main microcomputer 30. This reset signal is a pulse signal. Subsequently, in S860, a cutoff signal for turning off the third switch 55 is output to the high-side driver 54 to prohibit energization of the motor 40.

[0251] Subsequently, in S870, the output completed flag of the reset signal is set. Subsequently, in S873, since a rotation error other than a specific error has occurred, the output of permission for restarting the main microcomputer 30 is stopped.

[0252] Subsequently, the processes of S880 to S900 are executed. In S913, the rotation direction mismatch flag is cleared. Thus, this subroutine ends and the process proceeds to the process of S490. <3. Effects> According to the second embodiment described above, the following effects are achieved.

[0253] When the rotation error caused by the system error of the main microcomputer 30 is any one of the rapid acceleration, rapid deceleration, and speed exceeding of the motor 40, the monitoring microcomputer 60 permits the main microcomputer 30 to resume power supply to the motor 40. Thereby, since the main microcomputer 30 restarts the motor 40 before the trigger switch 240 is turned off, it is possible to suppress a decrease in working accuracy and working efficiency.

[0254] (13) When the type of rotation error is any one of rapid acceleration, rapid deceleration, and speed exceeding, in addition to the reset signal, a restart permission is output from the monitoring microcomputer 60 to the main microcomputer 30. Thereby, when the rotation error is any one of rapid acceleration, rapid deceleration, and speed exceeding, the main microcomputer 30 can resume power supply to the motor 40 before the trigger switch 240 is turned off.

[0255] (14) When the main microcomputer 30 receives a restart permission from the monitoring microcomputer 60 and detects that the trigger switch 240 is turned on when it restarts itself, it can resume power supply to the motor 40 and suppress a decrease in working efficiency.

[0256] (15) When the main microcomputer 30 restarts and the off state of the trigger switch 240 is detected, the output of the restart permission becomes unnecessary. Therefore, the monitoring microcomputer 60 can suppress the output of unnecessary signals by stopping the output of the restart permission after stopping the output of the reset signal and after detecting the off state of the trigger switch 240.

[0257] (16) When the main microcomputer 30 does not receive a restart permission when it restarts itself, it does not resume power supply to the motor 40 and continues to stop. Thereby, it is possible to suppress the generation of a large reaction torque when the main microcomputer 30 restarts, and thus suppress a decrease in working accuracy.

[0258] (17) When the main microcomputer 30 restarts itself and the rotational speed of the motor 40 is equal to or lower than a predetermined value, the main microcomputer 30 continues to stop without restarting the energization of the motor 40. As a result, when the main microcomputer 30 restarts, generation of a large reaction torque can be suppressed, and thus, a decrease in working accuracy can be suppressed.

[0259] (18) When the monitoring microcomputer 60 detects a discrepancy between the set direction and the actual rotational direction as a rotational error, the monitoring microcomputer 60 does not output restart permission to the main microcomputer 30. As a result, when the main microcomputer 30 restarts itself and the set direction and the actual rotational direction are different, the main microcomputer 30 continues to stop without restarting the energization of the motor 40. Therefore, when the main microcomputer 30 restarts, generation of a large reaction torque can be suppressed, and a decrease in working accuracy can be suppressed.

[0260] (Third Embodiment) Since the basic configuration of the third embodiment is the same as that of the second embodiment, differences will be described below. Note that the same reference numerals as those in the second embodiment denote the same configurations, and reference is made to the preceding description.

[0261] <1. Error Flag Check Process> Regarding the error flag check process that the monitoring microcomputer 60 according to the third embodiment executes in place of the error flag check process shown in FIGS. 14A and 14B in S480 of the monitoring microcomputer process, description will be made with reference to FIGS. 15A and 15B.

[0262] In S755, S765, and S775, the same processes as those in S770, S780, and S790 are executed. Subsequently, in S785, output of a reset signal to the main microcomputer 30 is stopped. This reset signal is a continuous signal output in the process of S845 described later. While the reset signal is being output, the main microcomputer 30 cannot energize the motor 40.

[0263] Subsequently, in S795, S805, and S815, the same processes as those in S800, S810, and S820 are executed. Subsequently, in S825, it is determined whether the current rotational speed of the motor 40 calculated from the position signal is equal to or less than a predetermined value. If it is determined that the rotational speed is greater than the predetermined value, the process proceeds to the process of S835. If it is determined that the rotational speed is equal to or less than the predetermined value, the process proceeds to the process of S845.

[0264] In S835, a reset signal for the pulse signal is output to the main microcomputer 30. That is, after the monitoring microcomputer 60 outputs a reset signal for one pulse, the output of the reset signal is stopped. After the output of the reset signal to the main microcomputer 30 stops, the main microcomputer 30 restarts. Then, the process proceeds to the process of S855. Therefore, when the rotational speed is greater than the predetermined value, the main microcomputer 30 restarts immediately after receiving a reset signal for one pulse.

[0265] On the other hand, in S845, a reset signal for the continuous signal is output to the main microcomputer 30. That is, the monitoring microcomputer 60 continuously outputs the reset signal and stops the output of the reset signal when the trigger switch 240 is turned off.

[0266] Therefore, when a rotation error occurs, if the rotational speed is greater than the predetermined value, the main microcomputer 30 can restart immediately after the rotation error occurs and energize the motor 40. On the other hand, when a rotation error occurs, if the rotational speed is equal to or less than the predetermined value, the main microcomputer 30 cannot restart until the trigger switch 240 is turned off, and thus cannot energize the motor 40.

[0267] Subsequently, in S855, S865, S875, S885, S895, S905, S915, S925, S935, S945, S955, S965, S975, and S985, the same processes as S822, S824, S826, S828, S830, S840, S850, S860, S870, S873, S880, S890, S900, and S913 are executed.

[0268] <2. Effects> According to the third embodiment described above, the same effects as the effects (12) to (18) achieved by the second embodiment are achieved, and the following effects are also achieved.

[0269] (19) When the monitoring microcomputer 60 outputs a reset signal, if the rotational speed of the motor 40 is equal to or lower than a predetermined value, the output of the reset signal is continued until the off state of the trigger switch 240 is detected. Thereby, when the main microcomputer 30 restarts, it is possible to suppress a sudden increase in the rotational speed of the motor 40 from a substantially stopped state.

[0270] (Other embodiments) Although the embodiments for implementing the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented with various modifications.

[0271] (a) In the above embodiment, as rotation-related values, the rotational speed, rotational acceleration, rotational deceleration, and rotational direction of the motor 40 were acquired and monitored. However, it is also possible to acquire and monitor only the rotational acceleration and rotational deceleration of the motor 40.

[0272] (b) In the above embodiment, the rotational acceleration and rotational deceleration of the motor 40 were calculated based on the position signal. However, the rotational acceleration and rotational deceleration of the motor 40 may be calculated based on the increase and decrease in the duty of the control signal (that is, the PWM signal).

[0273] (c) A plurality of functions of one component in the above embodiment may be realized by a plurality of components, or one function of one component may be realized by a plurality of components. Also, a plurality of functions of a plurality of components may be realized by one component, or one function realized by a plurality of components may be realized by one component. Further, a part of the configuration of the above embodiment may be omitted. Also, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of another of the above embodiments.

[0274] (d) In addition to the above-described electric power tool, the present disclosure can also be realized in various forms such as a system including the electric power tool as a component, a program for operating the monitoring microcomputer, a program for operating the main microcomputer, a non-transitory tangible recording medium such as a semiconductor memory storing these programs, and a method.

Explanation of Reference Numerals

[0275] 1... Electric power tool, 30... Main microcomputer, 30a, 60a... CPU, 30b, 60b... Memory, 36... Voltage guarantee circuit, 36a... First guarantee circuit, 36b... Second guarantee circuit, 38... First switch, 39... Second switch, 40... Motor, 40a... Load side shaft, 41... Position sensor, 42... Motor driver, 43... Current detection circuit, 44... Overcurrent detection latch circuit, 51... Temperature detection circuit, 51a... First temperature detection circuit, 51b... Second temperature detection circuit, 52... Battery voltage detection circuit, 52a... First voltage detection circuit, 52b... Second voltage detection circuit, 53... Surge killer capacitor, 54... High side driver, 55... Third switch, 60... Monitoring microcomputer, 240... Trigger switch, 240a... First trigger circuit, 240b... Second trigger circuit, 260... Forward / reverse switch, 260a... First forward / reverse circuit, 260b... Second forward / reverse circuit, 270... Signal terminal, 290... Display unit, 300... Battery pack.

Claims

1. A motor configured to generate a rotational force, A trigger switch configured to drive the motor when on and stop the motor when off, A tip tool configured to be driven by the rotational force, A first microcomputer, A second microcomputer, and The second microcomputer includes A rotation error detection unit configured to detect a rotation error of the motor, A signal output unit configured to output a reset signal to the first microcomputer when the rotation error is detected by the rotation error detection unit. The first microcomputer includes A first trigger detection unit configured to detect the state of the trigger switch, When the reset signal is received and restarted during energization of the motor, if the rotation error is any of rapid acceleration, rapid deceleration, and speed exceeding of the motor, and the first trigger detection unit detects that the trigger switch is on, a power supply control unit configured to resume power supply to the motor. An electric working machine.

2. The signal output unit is configured to output a specific error signal to the first microcomputer in addition to the reset signal when the type of the rotation error detected by the rotation error detection unit is any of rapid acceleration, rapid deceleration, and speed exceeding. The electric working machine according to claim 1.

3. The power supply control unit is configured to resume power supply to the motor when the first microcomputer restarts, receives the specific error signal, and the first trigger detection unit detects that the trigger switch is on. The electric working machine according to claim 2.

4. The second microcomputer further includes a second trigger detection unit configured to detect the state of the trigger switch, The signal output unit is configured to stop outputting the reset signal and stop outputting the specific error signal after the second trigger detection unit detects that the trigger switch is off. The electric working machine according to claim 2 or 3.

5. When the first microcomputer restarts and the specific error signal has not been received and the first trigger detection unit detects that the trigger switch is turned on, the power supply control unit is configured to stop supplying power to the motor. The electric working machine according to any one of claims 2 to 4.

6. When the first microcomputer restarts and the rotational speed of the motor is equal to or lower than a predetermined value, the power supply control unit is configured to stop supplying power to the motor. The electric working machine according to any one of claims 2 to 5.

7. The second microcomputer further includes a second trigger detection unit configured to detect the state of the trigger switch. When outputting the reset signal, if the rotational speed of the motor is equal to or lower than a predetermined value, the signal output unit is configured to continue outputting the reset signal until the second trigger detection unit detects that the trigger switch is turned off. The electric working machine according to any one of claims 2 to 6.

8. The electric working machine further includes a direction setting unit configured to indicate the rotational direction of the motor. The rotation error detection unit is configured to detect, as the rotation error, a discrepancy between the rotational direction set by the direction setting unit and the actual rotational direction of the motor. When the rotation error detection unit detects the discrepancy as the rotation error, the signal output unit is configured to stop outputting the specific error signal. The electric working machine according to any one of claims 2 to 7.

9. When the first microcomputer restarts and the specific error signal has not been received and the first trigger detection unit detects that the trigger switch is turned on, the power supply control unit stops supplying power to the motor until the first trigger detection unit once detects that the trigger switch is turned off and then the first trigger detection unit detects that the trigger switch is turned on again. The electric working machine according to claim 5.

10. The rotation error detection unit detects the rapid acceleration as the rotation error when the rotational acceleration of the motor differs from the acceleration allowable value, and detects the rapid deceleration as the rotation error when the rotational deceleration of the motor differs from the deceleration allowable value. When the rotational speed of the motor is different from the speed tolerance value, it is configured to detect the speed excess as the rotational error. The power-operated work machine according to any one of claims 2 to 9.

11. The second microcomputer further includes a second trigger detection unit configured to detect the state of the trigger switch. The rotational error detection unit is configured to detect the rotational error while the trigger switch is detected as being on by at least the second trigger detection unit. The power-operated work machine according to any one of claims 2 to 10.

12. The second microcomputer further includes a current detection unit configured to detect the value of the current flowing through the motor. The rotational error detection unit is configured to obtain the rotational deceleration of the motor when the trigger switch is detected as being on by the second trigger detection unit and the value of the current detected by the current detection unit is 0. The power-operated work machine according to claim 11.

13. The power-operated work machine further includes a first energization circuit provided in the supply line from the power supply source to the motor. The second microcomputer a first cutoff unit configured to output a first cutoff signal to the first energization circuit to cut off the first energization circuit when the mismatch is detected as the rotational error by the rotational error detection unit; a second trigger detection unit configured to detect the state of the trigger switch; a first energization unit configured to output a first energization signal to the first energization circuit to energize the first energization circuit when the trigger switch is detected as being off by the second trigger detection unit after the energization to the motor is cut off by the first cutoff unit. The power-operated work machine according to claim 8.

14. The first cutoff unit is configured to output the first cutoff signal to the first energization circuit when the power supply voltage input to the second microcomputer drops. The power-operated work machine according to claim 13.

15. The power-operated work machine further includes a second energization circuit provided in the supply line. The first microcomputer a second cutoff unit configured to output a second cutoff signal to the second energization circuit to cut off the second energization circuit. A signal detection unit configured to detect the first cutoff signal output from the first cutoff unit or the first energization signal output from the first energization unit; When the first microcomputer restarts, in a case where the specific error signal has not been received, after the second energization circuit is cut off by the second cutoff unit, when the first trigger detection unit detects that the trigger switch is turned off, and after the signal detection unit detects the first energization signal, in response to the first trigger detection unit detecting that the trigger switch is turned on, a second energization unit configured to output a second energization signal to the second energization circuit to energize the second energization circuit; and further comprising The electric working machine according to claim 13 or 14.

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