Electric power shovels, on-site electrical systems, and methods for diagnosing electric power shovels

Abstract

An electric working machine of one aspect of the present disclosure includes a motor, a tool driving portion, an instruction receiving portion, a diagnosis circuit, and a result transmitting portion. The diagnosis circuit performs a failure diagnosis on the electric working machine in response to the instruction receiving portion receiving a diagnosis instruction signal from a diagnosis device. The result transmitting portion transmits a diagnosis result signal to the diagnosis device. The diagnosis result signal indicates a result of the failure diagnosis performed by the diagnosis circuit.

Description

Technical Field

[0001] This disclosure relates to the diagnosis of electric work machines. Background Technology

[0002] Japanese Patent Application Publication No. 2019-123027 discloses an electric work machine that uses a mechanism to estimate the fault location of the electric work machine based on usage records stored in the machine, and then informs the user of the estimated fault location. Summary of the Invention

[0003] The aforementioned electric work machine was used to estimate the location of the fault based on usage records, rather than to determine the location of the fault based on the latest condition of the electric work machine.

[0004] Furthermore, the aforementioned electric work machine was not actually driven to locate the fault.

[0005] One aspect of this disclosure is the expectation of being able to pinpoint the location of a fault in an electric work machine with greater accuracy.

[0006] One aspect of this disclosure includes an electric work machine comprising a motor, a tool drive unit, a command receiving unit, a diagnostic circuit, and / or a result sending unit. The motor generates rotational force. The tool drive unit receives the rotational force to drive a tool. The command receiving unit receives diagnostic command signals from a diagnostic device. The diagnostic circuit performs fault diagnosis on the electric work machine in response to the command receiving unit receiving the diagnostic command signals. The result sending unit sends a diagnostic result signal to the diagnostic device. The diagnostic result signal indicates the result of the fault diagnosis performed by the diagnostic circuit.

[0007] If the electric work machine receives the diagnostic command signal from the diagnostic device, it will actually perform the fault diagnosis. As a result, the fault location can be determined with higher accuracy compared to speculating on the fault location.

[0008] This electric work platform does not rely on past usage records to estimate the location of the fault, but rather determines the fault location based on the latest condition of the machine. Therefore, this electric work platform can determine the fault location with greater accuracy based on its current state.

[0009] The electric work machine may also include a voltage detection unit, a display, and / or an operating switch. The voltage detection unit detects the voltage of the battery that supplies power to the motor. The display shows information about the electric work machine. The operating switch is operated by the user of the electric work machine. The diagnostic circuit can diagnose the voltage detection unit, the display, and / or the operating switch during fault diagnosis.

[0010] The aforementioned electric work machine can determine the faults of the voltage detection unit, the display, and / or the operating switch.

[0011] The display may have multiple LEDs. In the fault diagnosis, the diagnostic circuit may (i) drive the multiple LEDs to a preset display state, and then (ii) diagnose the display based on the magnitude of the current flowing through the multiple LEDs. The preset display state may correspond to a situation where all the multiple LEDs are lit or all are off.

[0012] The electric work machine may also include a motor drive circuit, a motor current detection unit, and / or a rotational position detection unit. The motor drive circuit supplies current to the motor. The motor current detection unit detects the magnitude of the current flowing through the motor. The rotational position detection unit detects the rotational position of the motor.

[0013] The diagnostic circuit can diagnose the motor drive circuit, the motor current detection unit, and / or the rotational position detection unit during fault diagnosis. The aforementioned electric work machine can pinpoint the fault location related to the motor drive with higher accuracy.

[0014] The diagnostic circuit can perform fault diagnosis on the motor drive circuit, the motor current detection unit, and the rotational position detection unit in sequence, following the order of the motor drive circuit, the motor current detection unit, and the rotational position detection unit.

[0015] If the motor drive circuit malfunctions, current cannot be supplied to the motor, thus preventing the motor from being driven. That is, even if the motor current detection unit is functioning correctly, it cannot detect the magnitude of the current if the motor drive circuit malfunctions. Furthermore, even if the rotational position detection unit is functioning correctly, it cannot detect the rotational position of the motor if the motor drive circuit malfunctions.

[0016] Following the above sequence, a fault in the motor drive circuit can be identified first. As a result, it is possible to prevent the motor current detection unit and / or the rotational position detection unit from erroneously identifying a fault as occurring due to a fault in the motor drive circuit.

[0017] In the event of a malfunction in the motor current detection unit, the magnitude of the current flowing through the motor cannot be accurately detected. As a result, there is a potential serious hazard of failing to detect excessive current flowing through the motor. By assigning a higher priority to the diagnosis of the motor current detection unit than to the diagnosis of the rotational position detection unit, malfunctions in the motor current detection unit can be detected at an earlier stage, thereby preventing serious hazards from occurring. Therefore, the aforementioned electric work machine not only prevents incorrect identification of the fault location but also prevents the occurrence of serious hazards.

[0018] The motor drive circuit can be configured in any manner. The motor drive circuit may include multiple switching elements configured to turn on or off the current flowing to the motor.

[0019] The diagnostic circuit can diagnose the motor drive circuit in any manner. In the fault diagnosis, the diagnostic circuit can (i) alternately turn on at least one of the plurality of switching elements each time, and then (ii) diagnose the motor drive circuit based on the magnitude of the current detected by the motor current detection unit.

[0020] The diagnostic circuit can diagnose the motor current detection unit in any manner. In the fault diagnosis, the diagnostic circuit can (i) supply the current to the motor via the motor drive circuit, and then (ii) diagnose the motor current detection unit based on the magnitude of the current detected by the motor current detection unit.

[0021] The diagnostic circuit can diagnose the rotational position detection unit in any manner. In the fault diagnosis, the diagnostic circuit can (i) rotate the motor at a preset rotational speed, and then (ii) diagnose the rotational position detection unit based on the rotational position detected by the rotational position detection unit.

[0022] The electric work machine can receive power from an external power source via a power cord. Alternatively, the electric work machine can receive power from a portable power source such as a battery pack. The battery pack can supply power to the motor.

[0023] The electric work machine may also include an external device connection portion configured to be selectively connected to the diagnostic device or the battery pack.

[0024] The electric work machine may also include a battery communication processing unit. This unit communicates with the battery pack connected to the external device connection. The battery communication processing unit can send signals related to the battery pack to the battery pack, or receive signals related to the battery pack from the battery pack.

[0025] The instruction receiving unit can receive the diagnostic instruction signal from the diagnostic device that is connected to the external device connection unit.

[0026] The result sending unit can send the diagnostic result signal to the diagnostic device that is connected to the external device connection unit.

[0027] When the external device connection is connected to the battery pack, the electric work machine communicates with the battery pack. Conversely, when the external device connection is connected to the diagnostic device, the electric work machine receives diagnostic command signals from the diagnostic device and sends diagnostic result signals to the diagnostic device.

[0028] That is, the electric work machine will not be connected to both the battery pack and the diagnostic device simultaneously. As a result, the fault diagnosis is only performed when the electric work machine is connected to the diagnostic device. Therefore, it is possible to prevent the fault diagnosis from being performed against the user's will, and thus to prevent accidents that could occur due to the electric work machine being operated while performing the fault diagnosis, resulting in injury to the user.

[0029] The external device connection portion can be configured in any manner. The external device connection portion may include a power terminal configured to receive power supplied from the battery pack to the motor in response to the external device connection portion being connected to the battery pack. And / or, the external device connection portion may include a signal terminal configured to form a communication path between the battery communication processing unit and the battery pack in response to the external device connection portion being connected to the battery pack.

[0030] The signal terminal may be configured to, in response to the external device connection unit being connected to the diagnostic device, (i) receive the diagnostic command signal from the diagnostic device, and (ii) receive the diagnostic result signal from the result transmission unit.

[0031] The electric work machine may also include a diagnostic device connection part, which is configured to connect the diagnostic device.

[0032] The electric work machine may also include a battery pack connection section configured to connect to the battery pack. The electric work machine may also include a first transmission path configured to transmit a diagnostic command signal from the diagnostic device connection section to the command receiving section. The electric work machine may also include a second transmission path configured to transmit a diagnostic result signal from the result sending section to the diagnostic device connection section.

[0033] The aforementioned electric work machine can receive power from the battery pack and can determine the location of the fault. The first transmission path and the second transmission path can both be wired paths or both be wireless paths.

[0034] The electric work machine may also include a wireless communication unit configured to communicate wirelessly with the diagnostic device.

[0035] The instruction receiving unit can receive the diagnostic instruction signal from the diagnostic device via the wireless communication unit. The result sending unit can send the diagnostic result signal to the diagnostic device via the wireless communication unit.

[0036] In addition to the aforementioned electric work machine, another aspect of the field electrical system disclosed herein also includes the diagnostic device. The diagnostic device may be configured to (i) send the diagnostic command signal to the electric work machine, and (ii) receive the diagnostic result signal from the electric work machine.

[0037] The aforementioned on-site electrical system can pinpoint the location of the fault in the electric work machine with greater accuracy.

[0038] Another aspect of this disclosure is a method for diagnosing an electric work platform, comprising the following steps:

[0039] The diagnostic device sends a diagnostic command signal to the electric work machine;

[0040] In response to the electric work machine receiving the diagnostic command signal, fault diagnosis is performed on the electric work machine; and / or

[0041] The electric work machine sends a diagnostic result signal, indicating the result of the fault diagnosis, to the diagnostic device.

[0042] According to the above method, the fault location of the electric work machine can be determined with higher accuracy. Attached Figure Description

[0043] Figure 1 This is a longitudinal sectional view of the electric work machine according to the first embodiment.

[0044] Figure 2 This is a block diagram illustrating the electrical structure of the field electrical system according to the first embodiment.

[0045] Figure 3 This is a flowchart illustrating the main program involved in the first embodiment.

[0046] Figure 4 This is a flowchart illustrating the communication-related processing involved in the first embodiment.

[0047] Figure 5 This is a flowchart illustrating the diagnostic communication process involved in the first embodiment.

[0048] Figure 6 This is a flowchart illustrating the diagnostic process for the switching element according to the first embodiment.

[0049] Figure 7 This is a flowchart illustrating the current detection and diagnostic process according to the first embodiment.

[0050] Figure 8 This is a flowchart illustrating the rotation sensor diagnostic process according to the first embodiment.

[0051] Figure 9 This is a flowchart illustrating the voltage detection and diagnostic process involved in the first embodiment.

[0052] Figure 10 This is a flowchart illustrating the display panel diagnostic process according to the first embodiment.

[0053] Figure 11 This is a flowchart illustrating the triggering of SW diagnostic processing according to the first embodiment.

[0054] Figure 12 This is a block diagram illustrating the configuration of a second tool body and a second diagnostic device according to another embodiment.

[0055] Figure 13 This is a block diagram illustrating the configuration of a third diagnostic device according to yet another embodiment.

[0056] Figure 14 This is a flowchart illustrating a variation of diagnostic communication processing. Detailed Implementation

[0057] Exemplary embodiments of this disclosure will now be described with reference to the accompanying drawings.

[0058] This disclosure is not limited to the following exemplary embodiments, and various methods can be adopted within the technical scope of this disclosure.

[0059] [1. First Embodiment]

[0060] [1-1. Structure of an electric work platform]

[0061] like Figure 1 As shown, the electric work machine 2 in this first embodiment is a cordless (or rechargeable) impact screwdriver. The electric work machines involved in this disclosure are not limited to cordless impact screwdrivers, but include all devices such as power tools and gardening tools configured to drive the tool via the rotational force (driving force) of a motor. Examples of power tools include circular saws, screwdrivers, cleaners, and hammer drills. Examples of gardening tools include lawnmowers, trimmers, and blowers.

[0062] The electric work machine 2 includes a first tool body 10. The first tool body 10 includes a housing 102. The housing 102 is located at its rear ( Figure 1 The left side) houses the motor 60. Inside the housing 102, the hammer cover 105 is assembled in front of the motor 60. Figure 1 (Right side). The hammer cover 105 is bell-shaped, and the impact mechanism 106 is housed inside the hammer cover 105. The impact mechanism 106 has a main shaft 107 with a hollow part.

[0063] The main shaft 107 is housed on the rear end side of the hammer housing 105. A ball bearing 108 is provided on the rear end side inside the hammer housing 105. The ball bearing 108 supports the outer periphery of the rear end of the main shaft 107.

[0064] A planetary gear mechanism 109 is provided in front of the ball bearing 108. The planetary gear mechanism 109 has a pair of planetary gears (not shown) that are supported symmetrically with respect to the main shaft 107. An internal gear 111 is provided on the inner circumferential surface of the hammer cover 105 at its rear end. The planetary gear mechanism 109 meshes with the internal gear 111.

[0065] The motor 60 has an output shaft 112. A pinion 113 is provided at the front end of the output shaft 112. The planetary gear mechanism 109 meshes with the pinion 113.

[0066] In addition to the main shaft 107 mentioned above, the impact mechanism 106 also includes a hammer body 114, an anvil 115, and a coil spring 116.

[0067] The hammer body 114 is disposed on the outer periphery of the main shaft 107. More specifically, the hammer body 114 is rotatable integrally with the main shaft 107 and is connected to the main shaft 107 in a manner that allows it to move axially. A helical spring 116 applies force forward to the hammer body 114.

[0068] Anvil 115 is positioned in front of hammer body 114. The front end of spindle 107 is inserted into the rear end of anvil 115, and spindle 107 supports anvil 115 so that it can rotate.

[0069] A bearing 120 is provided inside the front end of the housing 102. The bearing 120 supports the anvil 115 so that it can rotate freely about the main shaft 107 but cannot be displaced along the main shaft 107.

[0070] A retaining sleeve 119 is provided at the front end of the anvil 115. The retaining sleeve 119 is configured to mount various tool heads such as screwdriver bits or socket bits (illustration omitted). Figure 1 It can be clearly seen that the output shaft 112 of the motor 60, the main shaft 107, the hammer body 114, the anvil 115, and the ferrule 119 are coaxially configured.

[0071] A first impact protrusion 117A and a second impact protrusion 117B are provided on the front end face of the hammer body 114. The first impact protrusion 117A and the second impact protrusion 117B are 180° apart in the circumferential direction. The first impact protrusion 117A and the second impact protrusion 117B apply an impact force to the anvil 115.

[0072] A first impact arm 118A and a second impact arm 118B are provided at the rear end of the anvil 115. The first impact arm 118A and the second impact arm 118B are 180° apart in the circumferential direction.

[0073] The hammer body 114 is subjected to force on the front end of the main shaft 107 by means of the force of the helical spring 116 and is held on the front end of the main shaft 107. In response, the first impact protrusion 117A and the second impact protrusion 117B abut against the first impact arm 118A and the second impact arm 118B, respectively.

[0074] In this state, if the main shaft 107 is rotated by the rotational force of the motor 60 via the planetary gear mechanism 109, the hammer 114 rotates together with the main shaft 107, and the rotational force of the hammer 114 is transmitted to the anvil 115 via the first impact protrusion 117A and the second impact protrusion 117B, as well as the first impact arm 118A and the second impact arm 118B.

[0075] As a result, the tool head installed at the front end of the anvil 115 rotates. With a screwdriver head installed at the front end of the anvil 115, thread tightening can be achieved by rotating the screwdriver head.

[0076] If the screw is tightened to a predetermined position (or predetermined depth), a torque greater than a predetermined torque must be applied to the anvil 115. In connection with this, the rotational force (torque) of the hammer 114 relative to the anvil 115 must also reach a predetermined torque or greater.

[0077] As a result, the hammer body 114 displaces backward against the force of the coil spring 116, and the first impact protrusion 117A and the second impact protrusion 117B pass over the first impact arm 118A and the second impact arm 118B, respectively. That is, the first impact protrusion 117A and the second impact protrusion 117B temporarily detach from the first impact arm 118A and the second impact arm 118B, respectively.

[0078] Subsequently, the hammer body 114 rotates together with the main shaft 107 and moves forward again with the help of the helical spring 116. The first impact protrusion 117A and the second impact protrusion 117B impact the first impact arm 118A and the second impact arm 118B respectively along the rotation direction of the hammer body 114.

[0079] Therefore, in the electric work machine 2 of this first embodiment, whenever a torque greater than a predetermined torque is applied to the anvil 115, the hammer 114 repeatedly impacts the anvil 115. By intermittently applying the impact force of the hammer 114 to the anvil 115 in this manner, screws can be tightened to the workpiece with high torque.

[0080] The first tool body 10 has a portion extending from the lower part of the outer casing 102 ( Figure 2 A handle portion 103 protrudes from the lower side of the motor. The handle portion 103 is configured for the user of the electric work machine 2 to hold. A trigger 121 is provided above the handle portion 103.

[0081] The trigger 121 includes an operable part 121a and a detection part 121b. The operable part 121a is configured to be operated by a user, more specifically, by being pulled by the user's finger.

[0082] The detection unit 121b detects the operated state of the operated unit 121a. More specifically, the detection unit 121b includes a trigger switch 23 (hereinafter referred to as SW) and an operation amount detection unit (not shown). The trigger switch SW23 is configured to be turned on by pulling the operated unit 121a. The operation amount detection unit is configured such that the resistance value of the operation amount detection unit changes according to the operation amount (pulling amount) of the operated unit 121a.

[0083] A rotation direction selector SW122 is provided on the upper side of the trigger 121 (the lower end side of the housing 102) for switching the rotation direction of the motor 60 to either forward or reverse. In this first embodiment, when viewed from the rear end of the electric work machine 2, the right-hand rotation direction corresponds to the forward rotation direction of the motor 60. The rotation direction opposite to this forward rotation direction corresponds to the reverse rotation direction of the motor 60.

[0084] An illumination unit 123 is provided at the lower front of the housing 102. The illumination unit 123 illuminates light in front of the electric work machine 2 in response to the trigger 121 being pulled. The illumination unit 123 in this first embodiment is equipped with an LED as a light source.

[0085] A display panel 24 is provided at the lower front part of the handle 103. The display panel 24 displays the remaining power of the battery pack 70 installed in the first tool body 10 and / or the operating mode of the electric work machine 2.

[0086] The handle 103 may have a mode switch SW (illustration omitted), an impact force selection SW (illustration omitted), and a lighting SW (illustration omitted) near the display panel 24.

[0087] The electric work machine 2 can have two or more operating modes. These operating modes may include a normal mode and a variable speed mode. The normal mode is configured to control the rotation of the motor 60 based on the pull amount of the trigger 121. The variable speed mode is configured to switch the rotation of the motor 60 from low speed to high speed. These operating modes are switched using a mode switch SW.

[0088] More specifically, the mode switch SW is a switch that becomes active when operated (pressed) by the user. Whenever the mode switch SW is operated, the electric work machine 2 is selectively set to either normal mode or variable speed mode.

[0089] The impact force selection SW is a switch used to select the magnitude of the impact force applied from the hammer 114 to the anvil 115 (and consequently the magnitude of the torque applied to the tool head). More specifically, the impact force selection SW selects one of a plurality of preset control modes. In each of the plurality of control modes, an individual rotation speed of the motor 60 is set, corresponding to low-speed rotation and high-speed rotation, respectively. And / or, each of the plurality of control modes is set with an individual rate of change of the rotation speed of the motor 60 when changing from low-speed rotation to high-speed rotation. The impact force selection SW is activated when the operation mode is set to variable speed mode. The impact force selection SW is deactivated when the operation mode is set to normal mode.

[0090] The lighting switch SW is used to determine whether to turn on the lighting unit 123 in response to the trigger 121 being pulled.

[0091] The handle portion 103 has a first connector 20a at its lower end. The first connector 20a is configured to be detachably connected to the battery pack 70. The battery pack 70 is mounted to the handle portion 103 by sliding from the front side to the rear side of the first connector 20a.

[0092] [1-2. Electrical Structure]

[0093] Reference Figure 2 The electrical structure of the electric work machine 2 will be described.

[0094] like Figure 2 As shown, the first tool body 10, in addition to the motor 60 mentioned above, also has a controller 20 and a rotation sensor 26.

[0095] In this first embodiment, the motor 60 is a three-phase brushless motor. Therefore, the motor 60 has armature windings (not shown) for the U phase, V phase, and W phase of the motor 60, respectively.

[0096] The rotation sensor 26 detects the rotational position (rotation angle) of the motor 60. The rotation sensor 26 may include three Hall elements (not shown) and a Hall IC (not shown). The three Hall elements may be associated with the U-phase winding, V-phase winding, and W-phase winding, respectively. The Hall IC detects the rotational position of the rotor (not shown) of the motor 60. In this first embodiment, the rotation sensor 26 generates a rotation detection signal for each predetermined angle the rotor rotates.

[0097] The controller 20 includes a control circuit 30 and the aforementioned first connector 20a. The first connector 20a is configured to selectively connect to either the battery pack 70 or the first diagnostic device 3 via a first connection adapter 80. That is, the first connector 20a cannot be connected to multiple external devices (i.e., both the battery pack 70 and the first diagnostic device 3) simultaneously, but can be connected to only one external device (i.e., either the battery pack 70 or the first diagnostic device 3).

[0098] The first connector 20a includes a first positive terminal 11, a first negative terminal 12, a first signal terminal 13, a first serial communication terminal 14A, and a second serial communication terminal 14B. The first positive terminal 11 and the first negative terminal 12 form a path for supplying power from the battery pack 70 to the motor 60. The first signal terminal 13, the first serial communication terminal 14A, and the second serial communication terminal 14B form a communication path between the control circuit 30 and the battery pack 70. Alternatively, the first signal terminal 13, the first serial communication terminal 14A, and the second serial communication terminal 14B form a communication path between the control circuit 30 and the first diagnostic device 3. If the first connector 20a is connected to the first diagnostic device 3, a field electrical system 1 corresponding to an example of the field electrical system in this disclosure is formed.

[0099] In addition, the controller 20 includes a regulator 21, a battery voltage detection unit 22, the aforementioned trigger SW23, an LED substrate 241, a current detection circuit 25, a gate circuit 40, a drive circuit 50, and a temperature sensor 27.

[0100] If the battery pack 70 is connected to the first tool body 10, the regulator 21 receives power from the battery pack 70. The regulator 21 generates a power supply voltage (e.g., DC 5V) based on the received power. The power supply voltage is applied to at least the control circuit 30.

[0101] The battery voltage detection unit 22 detects the voltage value (hereinafter referred to as the battery voltage value) applied between the first positive terminal 11 and the first negative terminal 12 of the battery pack 70. The battery voltage detection unit 22 outputs an analog signal representing the detected battery voltage value to the control circuit 30.

[0102] The user operates trigger SW23 to drive motor 60 or stop motor 60. If the user pulls trigger 121, SW23 is activated and outputs an activation signal to control circuit 30. If the user releases trigger 121, SW23 is deactivated and outputs a deactivation signal to control circuit 30.

[0103] Furthermore, the user operates trigger SW23 to adjust the rotational speed and torque of motor 60. A pulse signal (i.e., a pulse width modulation (PWM) signal) with a commanded duty cycle is applied to the U-phase, V-phase, and W-phase windings of motor 60. The commanded duty cycle is specified by control circuit 30. The target duty cycle is the target of the commanded duty cycle and is set according to the pull amount of trigger 121. The user adjusts the pull amount of trigger 121 according to the desired rotational speed and / or desired torque of motor 60. To decrease the rotational speed of motor 60 or to decrease the torque of motor 60, the user decreases the pull amount of trigger 121. Alternatively, to increase the rotational speed of motor 60 or to increase the torque of motor 60, the user increases the pull amount of trigger 121.

[0104] In other embodiments, in addition to the trigger 121, a switch and / or dial may be provided for the user to set the operating mode or target duty cycle of the first tool body 10. Alternatively, the target duty cycle may be set according to the operating mode.

[0105] An LED substrate 241 is disposed on a display panel 24 and is used to inform the user of various information, such as the operating status and abnormalities of the first tool body 10. The LED substrate 241 has multiple display LEDs 24a, which individually illuminate, flash, or turn off in response to commands from the control circuit 30, thereby informing the user of various information. In this first embodiment, the multiple display LEDs 24a display the operating mode of the electric work machine 2, the rotational speed of the motor 60, the rotational direction of the motor 60, and the remaining power of the battery pack 70. The LED substrate 241 outputs an analog signal to the control circuit 30, which represents the value of the current flowing through the LED substrate 241 (corresponding to the current flowing through the multiple display LEDs 24a) (hereinafter referred to as the LED substrate current value).

[0106] The drive circuit 50 is configured to supply current (hereinafter referred to as motor current) from the battery pack 70 to the U-phase winding, V-phase winding, and W-phase winding. More specifically, the drive circuit 50 includes a three-phase full-bridge circuit comprising first to sixth switching elements Q1 to Q6. First to third switching elements Q1 to Q3 function as high-side switches. Fourth to sixth switching elements Q4 to Q6 function as low-side switches. In this first embodiment, the first to sixth switching elements Q1 to Q6 are metal-oxide-semiconductor field-effect transistors (MOSFETs). However, the first to sixth switching elements Q1 to Q6 are not limited to MOSFETs and can be any switching element including insulated-gate bipolar transistors (IGBTs). In this first embodiment, the drive circuit 50 is disposed inside the handle portion 103. In other embodiments, the drive circuit 50 may be disposed elsewhere than inside the handle portion 103.

[0107] Temperature sensor 27 detects the temperature of drive circuit 50. Temperature sensor 27 outputs an analog signal representing the detected temperature to control circuit 30.

[0108] Gate circuit 40 individually switches on or off the first to sixth switching elements Q1 to Q6 according to multiple control signals output from control circuit 30, thereby sequentially supplying motor current to the U-phase winding, V-phase winding, and W-phase winding, thus causing motor 60 to rotate. If all the first to sixth switching elements Q1 to Q6 are off during the rotation of motor 60, motor 60 will rotate due to inertia. If, during the rotation of motor 60, (i) all the first to third switching elements Q1 to Q3 are off, and (ii) all the fourth to sixth switching elements Q4 to Q6 are on, then so-called short-circuit braking is applied to motor 60.

[0109] A current detection circuit 25 is located on the negative terminal line from the drive circuit 50 to the negative terminal 12. The current detection circuit 25 detects the value of the motor current (hereinafter referred to as the motor current value) output from the battery pack 70 to the motor 60. The current detection circuit 25 outputs an analog signal representing the detected motor current value to the control circuit 30.

[0110] The control circuit 30 in this first embodiment is in the form of a microcomputer. Therefore, the control circuit 30 includes a CPU 31 and a memory 32. The control circuit 30 may include devices to replace the microcomputer, or may include devices in addition to a microcomputer, such as combinations of electronic components like discrete components, application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), programmable logic devices such as field-programmable gate arrays (FPGAs), or combinations of the above.

[0111] The memory 32 is in the form of semiconductor memory, including volatile memory and / or non-volatile memory. The CPU 31 performs various processes by executing various programs stored in the memory 32.

[0112] The battery pack 70 can be a rechargeable battery pack. The battery pack 70 includes battery cells 78, control circuitry 75, and a battery pack connector 70a. In other embodiments, the battery pack 70 may include one or more additional battery cells connected in series or parallel to the battery cells 78. The battery pack connector 70a includes a positive battery terminal 71, a negative battery terminal 72, a battery signal terminal 73, a first battery communication terminal 74A, and a second battery communication terminal 74B.

[0113] The battery pack connector 70a is configured to connect to the first connector 20a. In response to the connection of the battery pack 70 to the first tool body 10, the battery positive terminal 71, the battery negative terminal 72, the battery signal terminal 73, the first battery communication terminal 74A, and the second battery communication terminal 74B are respectively connected to the first positive terminal 11, the first negative terminal 12, the first signal terminal 13, the first serial communication terminal 14A, and the second serial communication terminal 14B.

[0114] Battery block 78 includes one or more rechargeable secondary batteries (i.e., battery cells), such as lithium-ion batteries. In other embodiments, battery block 78 may include non-rechargeable primary batteries. Battery block 78 includes multiple battery cells connected in series. Battery block 78 includes a positive terminal connected to the positive terminal 71 of the battery. Battery block 78 includes a negative terminal connected to the negative terminal 72 of the battery.

[0115] The control circuit 75 in the first embodiment is in the form of a microcomputer. Therefore, the control circuit 75 includes a CPU 76 and a memory 77. The control circuit 75 may include devices that replace the microcomputer, or may include, in addition to a microcomputer, devices such as combinations of electronic components like discrete components, ASICs, ASSPs, programmable logic devices such as FPGAs, or combinations of the above.

[0116] The memory 77 is in the form of semiconductor memory, including volatile memory and / or non-volatile memory. The CPU 76 performs various processes by executing various programs stored in the memory 77.

[0117] Specifically, when the battery block 78 can discharge, the control circuit 75 outputs a discharge permission signal to the first tool body 10 via the battery signal terminal 73. Furthermore, when the battery block 78 cannot discharge, the control circuit 75 outputs a discharge prohibition signal to the first tool body 10 via the battery signal terminal 73. The discharge permission signal is, for example, a signal with a low logic level. The discharge prohibition signal is, for example, a signal with a high logic level.

[0118] Furthermore, the control circuit 75 performs full-duplex serial communication with the first tool body 10 via the first battery communication terminal 74A and the second battery communication terminal 74B. Specifically, the control circuit 75 sends information about the battery pack 70 (i.e., a serial signal) to the first tool body 10 via the first battery communication terminal 74A, and receives information about the first tool body 10 from the first tool body 10 via the second battery communication terminal 74B.

[0119] The first diagnostic device 3 performs fault diagnosis on the electric work machine 2. The first diagnostic device 3 includes a first connection adapter 80, a first processing unit 90, and a device power supply 91.

[0120] The first connection adapter 80 is connected to the first computing device 90 and the device power supply 91. The first connection adapter 80 is configured to be detachably connected to the first connector 20a of the first tool body 10 in place of the battery pack 70.

[0121] Therefore, the first computing device 90 is connected to the first tool body 10 via the first connection adapter 80. The device power supply 91 supplies power to the first tool body 10 via the first connection adapter 80.

[0122] The first adapter 80 includes an adapter positive terminal 81, an adapter negative terminal 82, an adapter signal terminal 83, a first adapter communication terminal 84A, and a second adapter communication terminal 84B.

[0123] In response to the connection of the first connection adapter 80 to the first tool body 10, the adapter positive terminal 81, the adapter negative terminal 82, the adapter signal terminal 83, the first adapter communication terminal 84A, and the second adapter communication terminal 84B are respectively connected to the first positive terminal 11, the first negative terminal 12, the first signal terminal 13, the first serial communication terminal 14A, and the second serial communication terminal 14B.

[0124] The device power supply 91 generates and outputs a DC voltage based on the AC voltage supplied from a commercial power source or other AC power source. The positive terminal of the device power supply 91 is connected to the positive terminal 81 of the adapter. The negative terminal of the device power supply 91 is connected to the negative terminal 82 of the adapter. When the first connection adapter 80 is connected to the first tool body 10, the device power supply 91 outputs a DC voltage to the first tool body 10 via the positive terminal 81 and the negative terminal 82 of the adapter.

[0125] The first processing unit 90 is connected to the adapter signal terminal 83, the first adapter communication terminal 84A, and the second adapter communication terminal 84B. When the first connection adapter 80 is connected to the first tool body 10, the first processing unit 90 is connected to the first tool body 10 via the adapter signal terminal 83, the first adapter communication terminal 84A, and the second adapter communication terminal 84B. As a result, the first processing unit 90 can send various information to or receive various information from the first tool body 10.

[0126] The first arithmetic unit 90 includes a control unit 90a. In this first embodiment, the control unit 90a is in the form of a microcomputer. Therefore, the control unit 90a includes a CPU (not shown) and a memory. The control unit 90a performs various processes by executing various programs stored in the memory via the CPU. The control unit 90a may include devices that replace the microcomputer, or may include devices other than a microcomputer, such as combinations of electronic components like discrete components, ASICs, ASSPs, programmable logic devices such as FPGAs, or combinations of the above.

[0127] The first arithmetic unit 90 also includes an instruction input unit 90b. The instruction input unit 90b is a device for a user to input instructions to the first arithmetic unit 90. The first arithmetic unit 90 can be a portable terminal device such as a laptop computer. The instruction input unit 90b can be, for example, a keyboard.

[0128] In the first arithmetic unit 90, if a user inputs various commands via the command input unit 90b, the control unit 90a performs processing according to the input commands. For example, if the user inputs a diagnostic execution command, the first arithmetic unit 90 performs diagnostic command processing. In the diagnostic command processing, the first arithmetic unit 90 sends a diagnostic command signal to the first tool body 10 and receives a diagnostic result signal from the first tool body 10.

[0129] [1-3. Main Program]

[0130] Reference Figure 3 The main program executed by the control circuit 30 is described.

[0131] like Figure 3 As shown, firstly, in S110, the control circuit 30 determines whether the time base has been passed. The time base is equivalent to the control cycle of the control circuit 30. If the time base has not been passed (S110: No), the control circuit 30 remains in standby mode until the time base is passed. If the time base has been passed (S110: Yes), the control circuit 30 proceeds to S120.

[0132] In S120, the control circuit 30 performs a switch (SW) operation detection process. Specifically, the control circuit 30 detects whether the trigger SW23 is in an on or off state based on an on or off signal input from the trigger SW23. If the SW operation detection process is complete, the control circuit 30 proceeds to S130.

[0133] In S130, the control circuit 30 performs analog-to-digital (A / D) conversion. Specifically, the control circuit 30 converts the analog signals input from the LED substrate 241, battery voltage detection unit 22, current detection circuit 25, and temperature sensor 27 into digital signal values. Thus, the control circuit 30 acquires the digital signal values ​​of the LED substrate current, motor current, battery voltage, and the temperature of the drive circuit 50. Once the A / D conversion is complete, the control circuit 30 proceeds to S140.

[0134] In S140, the control circuit 30 performs communication-related processing. Specifically, the control circuit 30 establishes serial communication with the connected external device via the first serial communication terminal 14A and the second serial communication terminal 14B. The control circuit 30 determines the type of the external device and sends and / or receives various information from the external device. In this first embodiment, the battery pack 70 and the first diagnostic device 3 correspond to the external device. If the communication-related processing is completed, the control circuit 30 proceeds to S150.

[0135] In S150, the control circuit 30 performs anomaly detection processing. Specifically, the control circuit 30 compares the motor current value, battery voltage value, and temperature of the drive circuit 50 obtained in S130 with their respective threshold values ​​to detect anomalies including overcurrent flowing to the motor 60, voltage drop in the battery pack 70, and overheating of the drive circuit 50. If the anomaly detection processing is complete, the control circuit 30 proceeds to S160.

[0136] In S160, the control circuit 30 performs motor control processing based on the state of trigger SW23, the state of battery pack 70, and the detection of an anomaly. In response to the predetermined drive conditions being met, the control circuit 30 drives the motor 60. The drive conditions are met when (i) trigger SW23 is in the on state, (ii) no anomaly is detected in S150, and (iii) the discharge permission flag is set. If the control circuit 30 receives a discharge permission signal from the control circuit 75, the discharge permission flag is set. If the control circuit 30 receives a discharge prohibition signal from the control circuit 75, the discharge permission flag is reset. In S160, the control circuit 30 can detect the rotational position of the rotor of the motor 60 based on the rotation detection signal generated by the rotation sensor 26. Additionally, the control circuit 30 can calculate the number of revolutions (or rotational speed) of the motor 60 based on the rotor's rotational position and the detection interval of the rotor's rotational position. Here, the number of revolutions corresponds to the number of revolutions per unit time (e.g., 1 minute). If the motor control processing is complete, the control circuit 30 proceeds to S170.

[0137] In S170, the control circuit 30 performs display processing. Specifically, the control circuit 30 informs the user of the operating status of the motor 60, the remaining power of the battery pack 70, and any detected abnormalities via the display panel 24 (more specifically, multiple display LEDs 24a). Once the display processing is complete, the control circuit 30 returns to S110.

[0138] [1-4. Communication-related processing]

[0139] Reference Figure 4 The details of the communication-related processing described above are explained.

[0140] like Figure 4 As shown, first, in S210, the control circuit 30 determines whether the initial communication is complete. If the initial communication is complete (S210: Yes), the control circuit 30 proceeds to S230. If the initial communication is not complete (S210: No), the control circuit 30 proceeds to S220.

[0141] In S220, the control circuit 30 performs initial communication processing. Specifically, if an external device is connected to the first tool body 10, the control circuit 30 establishes serial communication with the external device via the first serial communication terminal 14A and the second serial communication terminal 14B. The control circuit 30 determines the type of the external device based on the information received from the external device and completes the initial communication processing.

[0142] In S230, the control circuit 30 determines whether the external device is the first diagnostic device 3 (i.e., the control circuit 30 determines the external device). If the external device is the first diagnostic device 3 (S230: Yes), the control circuit 30 proceeds to S240. If the external device is not the first diagnostic device 3 (S230: No), the control circuit 30 proceeds to S250.

[0143] In S240, control circuit 30 performs diagnostic communication processing. Details of the diagnostic communication processing will be explained later.

[0144] In S250, control circuit 30 performs battery communication processing. Control circuit 30 communicates with battery pack 70, which is connected to first connector 20a. This communication includes sending and / or receiving battery-related signals.

[0145] More specifically, in the battery communication process, the control circuit 30 first performs an initial information acquisition process. In this initial information acquisition process, the control circuit 30 first sends information such as the model number of the first tool body 10 to, for example, the battery pack 70 via the first serial communication terminal 14A. Additionally, the control circuit 30 receives information such as internal resistance information or model number from, for example, the battery pack 70 via the second serial communication terminal 14B. The internal resistance information can indicate the internal resistance value of the battery pack 70. Or / and, the internal resistance information can also indicate the number of battery cells connected in parallel in the battery block 78. That is, the internal resistance information can be the internal resistance value itself, or it can be any information that can be used to calculate or estimate the internal resistance value.

[0146] If the initial information acquisition process is completed, the control circuit 30 performs normal information acquisition processing. In the normal information acquisition process, the control circuit 30 receives the temperature, remaining charge, and overload count value of the battery pack 70 via the second serial communication terminal 14B.

[0147] If the processing of S220, S240, and S250 is completed, the control circuit 30 ends the communication-related processing.

[0148] [1-5. Diagnostic Communication Processing]

[0149] Reference Figure 5 The details of the diagnostic communication process described above are explained.

[0150] First, in S310, the control circuit 30 performs command receiving processing, receiving a diagnostic command signal from the first diagnostic device 3 via the second serial communication terminal 14B. The diagnostic command signal may include a single diagnostic command or two or more diagnostic commands. In this first embodiment, the diagnostic command signal includes any one of a switching element diagnostic command, a current detection diagnostic command, a rotation sensor diagnostic command, a voltage detection diagnostic command, a display panel diagnostic command, and a trigger SW diagnostic command.

[0151] In the following step S320, the control circuit 30 determines whether a switching element diagnostic command has been received based on the received diagnostic command signal. If a switching element diagnostic command has been received (S320: Yes), the control circuit 30 proceeds to S330. If no switching element diagnostic command has been received (S320: No), the control circuit 30 proceeds to S340.

[0152] In S330, the control circuit 30 performs the switching element diagnostic process described later to diagnose faults in the first to sixth switching elements Q1 to Q6 respectively.

[0153] In S340, the control circuit 30 determines whether a current detection diagnostic command has been received based on the received diagnostic command signal. If a current detection diagnostic command has been received (S340: Yes), the control circuit 30 proceeds to S350. If no current detection diagnostic command has been received (S340: No), the control circuit 30 proceeds to S360.

[0154] In S350, the control circuit 30 performs the current detection and diagnostic process described later to diagnose faults in the current detection circuit 25.

[0155] In S360, the control circuit 30 determines whether a rotation sensor diagnostic command has been received based on the received diagnostic command signal. If a rotation sensor diagnostic command has been received (S360: Yes), the control circuit 30 proceeds to S370. If no rotation sensor diagnostic command has been received (S360: No), the control circuit 30 proceeds to S380.

[0156] In S370, the control circuit 30 performs the rotation sensor diagnostic process described later to diagnose a fault in the rotation sensor 26.

[0157] In S380, the control circuit 30 determines whether a voltage detection diagnostic command has been received based on the received diagnostic command signal. If a voltage detection diagnostic command has been received (S380: Yes), the control circuit 30 proceeds to S390. If no voltage detection diagnostic command has been received (S380: No), the control circuit 30 proceeds to S400.

[0158] In S390, the control circuit 30 performs the voltage detection and diagnostic processing described later to diagnose a fault in the battery voltage detection unit 22.

[0159] In step S400, the control circuit 30 determines whether a display panel diagnostic command has been received based on the received diagnostic command signal. If a display panel diagnostic command has been received (S400: Yes), the control circuit 30 proceeds to step S410. If no display panel diagnostic command has been received (S400: No), the control circuit 30 proceeds to step S420.

[0160] In S410, the control circuit 30 performs the display panel diagnostic process described later to diagnose faults in the multiple display LEDs 24a.

[0161] In S420, the control circuit 30 determines whether a diagnostic command to trigger the SW is received based on the received diagnostic instruction signal. If a diagnostic command to trigger the SW is received (S420: Yes), the control circuit 30 proceeds to S430. If no diagnostic command to trigger the SW is received (S420: No), the control circuit 30 terminates the diagnostic communication process.

[0162] In S430, the control circuit 30 performs the trigger SW diagnostic process described later to diagnose the fault of trigger SW23.

[0163] If any one of S330, S350, S370, S390, S410 and S430 is completed, the control circuit 30 ends the diagnostic communication process.

[0164] [1-6. Diagnostic and Handling of Switching Components]

[0165] Reference Figure 6 The details of the diagnostic and processing procedures for the aforementioned switching elements are explained below.

[0166] First, in S510, the control circuit 30 performs a first switch operation test. In the first switch operation test, the control circuit 30 sequentially and individually turns on the first to sixth switch elements Q1 to Q6, and determines whether current flows through the drive circuit 50. The control circuit 30 stores the results of determining the turning-on operation of the first to sixth switch elements Q1 to Q6 in the memory 32.

[0167] In the following S520, the control circuit 30 determines whether the first condition is met based on the result of the first switch operation test. If no current is detected for the closing operation of all the first to sixth switch elements Q1 to Q6, the first condition is met. In other words, if current is detected during the closing operation of at least one of the first to sixth switch elements Q1 to Q6, the first condition is not met. If the first condition is met (S520: Yes), the control circuit 30 proceeds to S550. If the first condition is not met (S520: No), the control circuit 30 proceeds to S530.

[0168] In S530, the control circuit 30 determines the diagnostic results of the first to sixth switching elements Q1 to Q6 as "abnormal closure state". "Abnormal closure state" refers to a so-called short-circuit fault. That is, in an "abnormal closure state", the source and drain of any one of the first to sixth switching elements Q1 to Q6 are short-circuited, resulting in the inability to disconnect the source and drain again. If all the first to sixth switching elements Q1 to Q6 are functioning normally, the first condition is met based on the results of the first switch operation test. However, if at least one of the first to sixth switching elements Q1 to Q6 is abnormally closed, the first condition is not met.

[0169] In S550, the control circuit 30 performs a second switching operation test. In this test, switching elements Q1 to Q6 (numbers 1 to 6) are sequentially switched on, two at a time, and it is determined whether current flows through the drive circuit 50. More specifically, the control circuit 30 switches on switching elements Q1 to Q6 according to a predetermined combination of the following 1 to 6.

[0170] • First combination: First switching element Q1 and fifth switching element Q5

[0171] • Second combination: First switching element Q1 and sixth switching element Q6

[0172] • Third combination: the second switching element Q2 and the fourth switching element Q4

[0173] • Fourth combination: Second switching element Q2 and sixth switching element Q6

[0174] • Fifth combination: the third switching element Q3 and the fourth switching element Q4

[0175] • Sixth combination: the third switching element Q3 and the fifth switching element Q5

[0176] If the current detection circuit 25 detects current in all combinations from 1 to 6, the control circuit 30 determines that current flows through the drive circuit 50. If the current detection circuit 25 does not detect current in any combination from 1 to 6, the control circuit 30 determines that current does not flow through the drive circuit 50. The control circuit 30 stores the results of determining the activation action for each of combinations 1 to 6 in the memory 32.

[0177] In the next step, S560, the control circuit 30 determines whether the second condition is met based on the result of the second switch operation test. The second condition is met if the current detection circuit 25 detects current in all combinations of the first to sixth switching operations. In other words, the second condition is not met if no current is detected in at least one combination of the first to sixth switching operations. If the second condition is met (S560: Yes), the control circuit 30 proceeds to S580. If the second condition is not met (S560: No), the control circuit 30 proceeds to S570.

[0178] In S570, the control circuit 30 determines the diagnostic results of the first to sixth switching elements Q1 to Q6 as "abnormal open state". In the "abnormal open state", the source and drain of any one of the first to sixth switching elements Q1 to Q6 are disconnected (e.g., burned out), resulting in the inability to reconnect the source and drain. If all first to sixth switching elements Q1 to Q6 are functioning normally, the second condition is met in terms of the results of the second switch operation test. However, if at least one of the first to sixth switching elements Q1 to Q6 is in an abnormal open state, the second condition is not met.

[0179] In S580, the control circuit 30 determines the diagnostic results of the first to sixth switching elements Q1 to Q6 as "normal".

[0180] If any one of S530, S570 and S580 is completed, then control circuit 30 enters S540.

[0181] In S540, the control circuit 30 sends the diagnostic results of the first to sixth switching elements Q1 to Q6 to the first diagnostic device 3 via the first serial communication terminal 14A. If the processing of S540 is completed, the control circuit 30 ends the switching element diagnostic processing.

[0182] [1-7. Current Detection, Diagnosis, and Processing]

[0183] Reference Figure 7 The details of the above-mentioned current detection and diagnostic processing are explained.

[0184] First, in S710, the control circuit 30 performs a current detection test. In this test, the control circuit 30 controls the drive circuit 50 to allow a predetermined diagnostic current to flow through the motor 60, and detects the magnitude of the actual current flowing through the drive circuit 50. More specifically, the control circuit 30 switches on two predetermined switching elements Q1 to Q6 for a predetermined on-time throughout the entire predetermined on-time to supply current to the motor 60. In response to the switching on of the two predetermined switching elements, the control circuit 30 stores the current value detected by the current detection circuit 25 in the memory 32.

[0185] After the two predetermined switching elements are turned on, the motor 60 immediately rotates. Subsequently, if current continues to be supplied to the motor 60 via these two switching elements, the rotation of the motor 60 stops, and the rotational position of the motor 60 is determined. In this case, the current flowing to the motor 60 and the drive circuit 50 has a predetermined value determined based on the battery voltage, the impedance of the drive circuit 50, the impedance of the motor 60 at the time of stopping, and the on-time (duty cycle) of the two predetermined switching elements.

[0186] Therefore, if the conditions for the current detection test are predetermined, and the normal range of current that should be detected by the current detection circuit 25 under those conditions is predetermined (hereinafter referred to as the normal current range), it is possible to determine whether the current detection circuit 25 is functioning properly. The normal current range can be determined based on the magnitude of the current measured in advance using the electric work machine 2. The normal current range may include a predetermined error. The conditions for the current detection test include, for example, the battery voltage value and the on-time (duty cycle) of the first to sixth switching elements Q1 to Q6.

[0187] In the next step, S720, the control circuit 30 determines whether the normal current condition is met based on the result of the current detection test. If the current value detected by the current detection test is within the normal current range, the normal current condition is met. Based on the result of the current detection test, if the normal current condition is met (S720: Yes), the control circuit 30 proceeds to S730. If the normal current condition is not met (S720: No), the control circuit 30 proceeds to S740.

[0188] In S730, the control circuit 30 determines the diagnostic result of the current detection circuit 25 as "normal". In S740, the control circuit 30 determines the diagnostic result of the current detection circuit 25 as "abnormal".

[0189] In the next step S750, the control circuit 30 sends the diagnostic results to the first diagnostic device 3 and ends the current detection diagnostic process.

[0190] [1-8. Rotation Sensor Diagnostic Processing]

[0191] Reference Figure 8 The details of the diagnostic process for the aforementioned rotary sensor are explained below.

[0192] First, in S810, the control circuit 30 performs a rotation detection test. In the rotation detection test, the control circuit 30 controls the drive circuit 50 to rotate the motor 60 at a predetermined rotation speed (hereinafter referred to as the diagnostic rotation speed) for performing diagnostics on the rotation sensor 26. In response to the rotation of the motor 60, the control circuit 30 stores the detection result of the rotation sensor 26 in the memory 32. The diagnostic rotation speed can be a low rotation speed such as 10 rpm to ensure user safety.

[0193] In the next step, S820, the control circuit 30 determines whether the normal sensor condition is met based on the result of the rotation detection test. If the detection result of the rotation sensor 26 corresponds to the rotational action of the motor 60 at the diagnostic rotational speed, the normal sensor condition is met. Regarding the result of the rotation detection test, if the normal sensor condition is met (S820: Yes), the control circuit 30 proceeds to S840. If the normal sensor condition is not met (S820: No), the control circuit 30 proceeds to S830.

[0194] Normal sensor conditions can be defined based on the changing patterns of the aforementioned rotation detection signal. Alternatively, normal sensor conditions can be defined based on the rotation speed calculated from the detection results of rotation sensor 26.

[0195] In S830, the control circuit 30 determines the diagnostic result of the rotation sensor 26 as "abnormal". In S840, the control circuit 30 determines the diagnostic result of the rotation sensor 26 as "normal".

[0196] In the next step S850, the control circuit 30 controls the drive circuit 50 to stop the motor 60. In S860, the control circuit 30 sends the diagnostic results of the rotation sensor 26 to the first diagnostic device 3 and ends the rotation sensor diagnostic process.

[0197] [1-9. Voltage Detection, Diagnosis, and Processing]

[0198] Reference Figure 9 The details of the voltage detection and diagnostic process described above are explained.

[0199] First, in S910, the control circuit 30 determines whether the voltage value detected by the battery voltage detection unit 22 is within a predetermined normal voltage range. The normal voltage range is predetermined based on the output voltage of the device power supply 91. For example, if the output voltage of the device power supply 91 is 18 [V], the normal voltage range can be set to 17 to 19 [V]. If the detected voltage value is within the normal voltage range (S910: Yes), the control circuit 30 proceeds to S930. If the detected voltage value is not within the normal voltage range (S910: No), the control circuit 30 proceeds to S920.

[0200] In S920, the control circuit 30 determines the diagnostic result of the battery voltage detection unit 22 as "abnormal". In S930, the control circuit 30 determines the diagnostic result of the battery voltage detection unit 22 as "normal".

[0201] In the next step S940, the control circuit 30 sends the diagnostic results to the first diagnostic device 3 and ends the voltage detection diagnostic process.

[0202] [1-10. Display Panel Diagnostic Processing]

[0203] Reference Figure 10 The details of the above-mentioned diagnostic processing for the display panel are explained.

[0204] First, in S1010, the control circuit 30 performs a first display test. In the first display test, the control circuit 30 controls multiple display LEDs 24a to set the display panel 24 to a predetermined first display state, and detects the LED substrate current value. In the first display state of this first embodiment, all of the multiple display LEDs 24a are lit.

[0205] In the next step, S1020, the control circuit 30 determines whether the first normal display condition is met based on the result of the first display test. If the LED substrate current value is within the first normal display current range, the first normal display condition is met. The first normal display current range is predetermined based on the LED substrate current value when all multiple display LEDs 24a are lit. Regarding the result of the first display test, if the first normal display condition is met (S1020: Yes), the control circuit 30 proceeds to S1050. If the first normal display condition is not met (S1020: No), the control circuit 30 proceeds to S1030.

[0206] In S1050, the control circuit 30 performs a second display test. In this second display test, the control circuit 30 controls multiple display LEDs 24a to set the display panel 24 to a predetermined second display state, and detects the LED substrate current value. In the second display state of this first embodiment, all multiple display LEDs 24a are turned off.

[0207] In the next step, S1060, the control circuit 30 determines whether the second normal display condition is met based on the results of the second display test. If the LED substrate current value is within the second normal display current range, the second normal display condition is met. The second normal display current range is predetermined based on the LED substrate current value when all multiple display LEDs 24a are turned off. If the second normal display condition is met (S1060: Yes), the control circuit 30 proceeds to S1080. If the second normal display condition is not met (S1060: No), the control circuit 30 proceeds to S1070.

[0208] In S1030, the control circuit 30 determines the diagnostic result of the display panel 24 as "lighting fault" and proceeds to S1040. In S1070, the control circuit 30 determines the diagnostic result of the display panel 24 as "off fault" and proceeds to S1040. In S1080, the control circuit 30 determines the diagnostic result of the display panel 24 as "normal" and proceeds to S1040. In S1040, the control circuit 30 sends the diagnostic result to the first diagnostic device 3 and ends the display panel diagnostic process.

[0209] [1-11. Triggering SW diagnostic processing]

[0210] Reference Figure 11 The details of triggering the SW diagnostic process described above are explained.

[0211] First, in S1110, the control circuit 30 determines whether the trigger SW23 is in the off state. When the first diagnostic device 3 is connected to the first tool body 10, the first tool body 10 cannot be used as a tool. In this case, the user does not operate the trigger SW23, and the trigger SW23 is normally in the off state. If the trigger SW23 is in the off state (S1110: Yes), the control circuit 30 proceeds to S1130. If the trigger SW23 is not in the off state (S1110: No), the control circuit 30 proceeds to S1120.

[0212] In S1120, the control circuit 30 determines the diagnostic result of triggering SW23 as "abnormal". In S1130, the control circuit 30 determines the diagnostic result of triggering SW23 as "normal".

[0213] In the next step S1140, the control circuit 30 sends the diagnostic result of triggering SW23 to the first diagnostic device 3 and ends the triggering SW diagnostic process.

[0214] [1-12. Effects]

[0215] As described above, if the first tool body 10 receives a diagnostic command signal from the first diagnostic device 3, it performs fault diagnosis in response to the diagnostic command contained in the diagnostic command signal. That is, the first tool body 10 does not infer the fault location based on past information, but actually performs fault diagnosis to determine the fault location. Therefore, since the first tool body 10 actually performs fault diagnosis in response to the diagnostic command signal, the accuracy of fault location determination can be improved compared to the case of inferring the fault location.

[0216] Furthermore, the first tool body 10 actually performs fault diagnosis in response to receiving a diagnostic command signal from the first diagnostic device 3. That is, the first tool body 10 diagnoses the fault location based on the latest state of the first tool body 10, rather than based on past usage record information. Therefore, since the first tool body 10 performs fault diagnosis based on the latest state, it is able to diagnose the fault location with higher accuracy.

[0217] Furthermore, in the first tool body 10, fault diagnosis is not performed by the first diagnostic device 3 outside the first tool body 10, but by the control circuit 30 inside the first tool body 10. Therefore, as long as a fault diagnosis program (or algorithm) suitable for the type of the first tool body 10 is stored in the control circuit 30, the first tool body 10 can prevent the fault diagnosis from being performed with an incorrect program.

[0218] Since the control circuit 30 performs fault diagnosis on at least the drive circuit 50, the current detection circuit 25, and the rotation sensor 26, it can determine the fault location of the main parts related to the drive of the motor 60 with higher accuracy compared to the case of estimation based on the use of recorded information.

[0219] Since the control circuit 30 performs diagnostics in the order of drive circuit 50, current detection circuit 25, and rotation sensor 26, it can first determine the fault of drive circuit 50. Therefore, it can prevent the tool body 10 from mistakenly judging the current detection circuit 25 and rotation sensor 26 as faulty due to a fault in drive circuit 50.

[0220] In the first tool body 10, for diagnostic purposes, the current detection circuit 25 is given a higher priority than the rotation sensor 26. Therefore, the first tool body 10 can detect faults in the current detection circuit 25 at an early stage, thereby preventing serious hazards such as overcurrent. Thus, according to the first tool body 10, false fault detection can be suppressed, and the occurrence of serious hazards can be prevented.

[0221] As described above, the first tool body 10 is configured to be selectively connected to either the battery pack 70 or the first diagnostic device 3. That is, diagnostics are only performed when the first tool body 10 is connected to the first diagnostic device 3. Therefore, it is possible to suppress the situation where diagnostics are performed when the first tool body 10 is connected to the battery pack 70 and the user can use it.

[0222] That is, since it is possible to suppress the situation where the first tool body 10 performs a diagnosis against the user's intention when it is connected to the battery pack 70, it is possible to suppress accidents caused by performing a diagnosis (such as user injury).

[0223] [1-13. Correspondence of Terms]

[0224] In this first embodiment, the first tool body 10 corresponds to an example of the electric work machine of this disclosure, and the planetary gear mechanism 109 and the impact mechanism 106 correspond to an example of the tool drive unit of this disclosure. The first connector 20a corresponds to an example of the external device connection unit of this disclosure. The first positive terminal 11 and the second negative terminal 12 correspond to an example of the power terminal of this disclosure, and the first signal terminal 13, the first serial communication terminal 14A, and the second serial communication terminal 14B correspond to an example of the signal terminal of this disclosure.

[0225] The control circuit 30 corresponds to an example of the instruction receiving unit, diagnostic circuit, result sending unit, and battery communication processing unit in this disclosure, and the battery voltage detection unit 22 corresponds to an example of the voltage detection unit in this disclosure. The display panel 24 corresponds to an example of the display in this disclosure, and the trigger SW23 corresponds to an example of the operation switch in this disclosure.

[0226] The drive circuit 50 corresponds to an example of the motor drive circuit in this disclosure, the current detection circuit 25 corresponds to an example of the motor current detection unit in this disclosure, and the rotation sensor 26 corresponds to an example of the rotation position detection unit in this disclosure.

[0227] [2. Other Implementation Methods]

[0228] The embodiments of this disclosure have been described above. However, this disclosure is not limited to the above embodiments and can be implemented in various ways without departing from the spirit of this disclosure.

[0229] (2a) In the first embodiment described above, the electric work machine 2 (more specifically, the first tool body 10) communicates with the first diagnostic device 3 via full-duplex serial communication. The communication method of this disclosure is not limited to full-duplex serial communication, but can also employ half-duplex serial communication.

[0230] Furthermore, in the first embodiment described above, the electric work machine 2 (specifically, the first tool body 10) is wired to the first diagnostic device 3 via the first connector 20a and the first connection adapter 80. The connection method disclosed herein is not limited to this form. For example, such as... Figure 12 As shown in the second tool body 10a, the electric work machine may include a second connector 20b and / or a wireless communication unit 28 in addition to the first connector 20a. In the second tool body 10a, components identical to those in the first tool body 10 are indicated by the same reference numerals as in the first embodiment.

[0231] The second connector 20b is configured to connect detachably to the first connection adapter 80 of the first diagnostic device 3. The second connector 20b includes a second positive terminal 41, a second negative terminal 42, a second signal terminal 43, a third serial communication terminal 44A, and a fourth serial communication terminal 44B. The second positive terminal 41 and the second negative terminal 42 form a path for supplying power from the device power supply 91 to the motor 60 via the first connection adapter 80. The second signal terminal 43, the third serial communication terminal 44A, and the fourth serial communication terminal 44B form a communication path between the control circuit 30 and the first arithmetic device 90. The second connector 20b is configured to receive diagnostic command signals from the first diagnostic device 3 and / or send diagnostic result signals to the first diagnostic device 3 via the third serial communication terminal 44A and the fourth serial communication terminal 44B.

[0232] The wireless communication unit 28 is configured to be with Figure 12 The second diagnostic device 3a shown is wirelessly connected. The second diagnostic device 3a includes a second processing unit 92. The second processing unit 92 differs from the first processing unit 90 in that it includes a wireless communication unit 90c. The wireless communication unit 90c performs wireless communication based on instructions from the control unit 90a. The wireless communication unit 28 communicates with the wireless communication unit 90c via wireless communication. Wireless communication includes short-range wireless communication. Examples of short-range wireless communication include wireless communication conforming to the Bluetooth (registered trademark) standard. The wireless communication unit 28 is configured to receive diagnostic instruction signals from the second diagnostic device 3a and / or send diagnostic result signals to the second diagnostic device 3a via wireless communication.

[0233] As described above, by adding the second connector 20b and the wireless communication unit 28, it is possible to perform fault diagnosis on the second tool body 10a based on the diagnostic command signal from the first diagnostic device 3 or the diagnostic command signal from the second diagnostic device 3a when the battery pack 70 is connected to the second tool body 10a.

[0234] Furthermore, the diagnostic device involved in this disclosure is not limited to the first diagnostic device 3 or the second diagnostic device 3a described above, and may also be configured as follows: Figure 13 The third diagnostic device 3b is shown. The third diagnostic device 3b includes the aforementioned second processing unit 92 and a second connection adapter 80a. The second connection adapter 80a differs from the first connection adapter 80 in that: (i) a wireless communication unit 85 is added, and (ii) the adapter signal terminal 83, the first adapter communication terminal 84A, and the second adapter communication terminal 84B are connected to the wireless communication unit 85. Therefore, the second connection adapter 80a can be detachably connected to the first connector 20a and the second connector 20b. The wireless communication unit 85 is wiredly connected to the control circuit 30 via the adapter signal terminal 83, the first adapter communication terminal 84A, and the second adapter communication terminal 84B. Therefore, the wireless communication unit 85 receives various information from and / or sends various information to the control circuit 30 via wired communication. Furthermore, the wireless communication unit 85 is wirelessly connected to the wireless communication unit 90c. The wireless communication unit 85 receives various information from and / or sends various information to the wireless communication unit 90c via wireless communication. The second computing device 92 is wirelessly connected to the first tool body 10 or the second tool body 10a via the second connection adapter 80a, and receives and / or sends various information to the first tool body 10 or the second tool body 10a.

[0235] As described above, in the third diagnostic device 3b, the second connection adapter 80a is wired to the first tool body 10 or the second tool body 10a, while the second computing device 92 is wirelessly connected to the second connection adapter 80a. The third diagnostic device 3b sends diagnostic command signals to the first tool body 10 or the second tool body 10a and receives diagnostic result signals from the first tool body 10 or the second tool body 10a.

[0236] In order to connect the diagnostic device to the tool body via wireless communication, any method can be considered, for example, the wireless communication unit can be installed in the tool body, or the wireless communication unit can be installed in the connection adapter connected to the tool body.

[0237] In the second tool body 10a, the second tool body 10a corresponds to an example of the electric work machine in this disclosure, the first connector 20a corresponds to an example of the external device connection part or battery pack connection part in this disclosure, the second connector 20b corresponds to an example of the diagnostic device connection part in this disclosure, and the wireless communication part 28 corresponds to an example of the wireless communication part in this disclosure.

[0238] In the second connector 20b, the second positive terminal 41 and the second negative terminal 42 can be omitted. In this case, power supplied from the battery pack 70 can be used instead of power supplied from the device power supply 91. As a result, the driving of the second tool body 10a and the diagnosis of the second tool body 10a based on the diagnostic command signal from the first diagnostic device 3 can be performed in parallel.

[0239] (2b) In the first embodiment described above, the diagnostic objects include, but are not limited to, the drive circuit 50, the current detection circuit 25, the rotation sensor 26, the battery voltage detection unit 22, the display panel 24, and the trigger SW23. For example, the diagnostic objects may include the temperature sensor 27. Alternatively, at least one of the drive circuit 50, the current detection circuit 25, the rotation sensor 26, the battery voltage detection unit 22, the display panel 24, and the trigger SW23 may be excluded from the diagnostic objects. Diagnosing the temperature sensor 27 may include determining whether the detected temperature of the temperature sensor 27 is within the normal temperature range. For example, the diagnosis may be performed without using the first tool body 10, and the presence of a fault in the temperature sensor 27 may be determined based on whether the detected temperature of the temperature sensor 27 is within the normal temperature range (e.g., within the range of 0°C to 50°C). The temperature sensor 27 may be determined to be normal if its detected temperature is within the normal temperature range. The temperature sensor 27 may be determined to be faulty if its detected temperature deviates from the normal temperature range.

[0240] (2c) In the first embodiment described above, the diagnostics are performed in the following order: drive circuit 50, current detection circuit 25, rotation sensor 26, battery voltage detection unit 22, display panel 24, and trigger SW23. However, the order of the diagnostics is not limited to the above order. For example, the diagnostics may also be performed in the following order: drive circuit 50, current detection circuit 25, rotation sensor 26, display panel 24, trigger SW23, and battery voltage detection unit 22.

[0241] (2d) In the first embodiment described above, an electric work machine driven by power from a battery pack was described. However, this disclosure is not limited to such electric work machines. This disclosure can be applied to, for example, electric work machines driven by power supplied from a commercial power source instead of power from a battery pack. Furthermore, this disclosure can be applied to electric work machines that receive power from both a battery pack and a commercial power source.

[0242] (2e) In the above embodiments, a configuration in which fault diagnosis is typically performed upon receiving a diagnostic command signal has been described, but this disclosure is not limited to this configuration. For example, diagnostic communication processing is not limited to the above. Figure 5 The process is shown below. Figure 14 The illustrated variation of the diagnostic communication process can have the following flow: determining whether all of the first to sixth switching elements Q1 to Q6 are functioning correctly, and not performing a diagnosis if any of the first to sixth switching elements Q1 to Q6 is not functioning correctly. Figure 14 In the middle, to and Figure 5 The steps shown are the same and are labeled with the same numbers.

[0243] In a modified example, if the control circuit 30 makes a positive determination in S340, it proceeds to S342, where it determines whether all of the first to sixth switching elements Q1 to Q6 are functioning correctly. If all of the first to sixth switching elements Q1 to Q6 are functioning correctly (S342: Yes), the control circuit 30 proceeds to S350 and performs current detection diagnostic processing. If any of the first to sixth switching elements Q1 to Q6 is not functioning correctly (S342: No), the control circuit 30 proceeds to S344 and sends a diagnostic not performed signal to the first diagnostic device 3 (S344). The diagnostic not performed signal notifies the first diagnostic device 3 that the diagnostic was not performed. If the control circuit 30 makes a positive determination in S360, it proceeds to S362 and determines whether all of the first to sixth switching elements Q1 to Q6 are functioning correctly. If all six switching elements Q1 to Q6 are functioning normally (S362: Yes), the control circuit 30 proceeds to S370 and executes the rotation sensor diagnostic process (S370). If any one of the six switching elements Q1 to Q6 is not functioning normally (S362: No), the control circuit 30 proceeds to S364 and sends a diagnostic failure signal to the first diagnostic device 3 (S364). If the control circuit 30 completes either S334 or S364, the diagnostic communication process ends. Therefore, it is possible to suppress the execution of current detection diagnostic processing and rotation sensor diagnostic processing if any one of the six switching elements Q1 to Q6 is not functioning normally, thereby suppressing a decrease in diagnostic accuracy.

[0244] Alternatively, the first diagnostic device 3, the second diagnostic device 3a, or the third diagnostic device 3b may be configured to not output current detection diagnostic commands and rotation sensor diagnostic commands when receiving any abnormal diagnostic result from any of the first to sixth switching elements Q1 to Q6.

[0245] (2f) The function of one constituent element in the above embodiments can be distributed among multiple constituent elements, or the functions of multiple constituent elements can be integrated into one constituent element. Furthermore, at least a portion of the configuration of the above embodiments can be replaced with a known configuration having the same function. Furthermore, a portion of the configuration of the above embodiments can be omitted. Furthermore, at least a portion of the configuration of the above embodiments can be added to the configuration of other embodiments, or at least a portion of the configuration of the above embodiments can be replaced with the configuration of other embodiments. Furthermore, all methods encompassed by the technical concept defined by the statements in the patent claims are embodiments of this disclosure.

Claims

1. An electric work machine, characterized in that, have: A motor is configured to generate rotational force; The tool drive unit is configured to receive the rotational force to drive the tool; The external device connection section is configured to selectively connect to either a diagnostic device or a battery pack; The battery communication processing unit is configured to communicate with the battery pack that has been connected to the external device connection unit; The instruction receiving unit is configured to receive diagnostic instruction signals from the diagnostic device that has been connected to the external device connection unit; The diagnostic circuit is configured to perform fault diagnosis on the electric work machine in response to the instruction receiving unit receiving the diagnostic instruction signal; and The result transmission unit is configured to send a diagnostic result signal to the diagnostic device connected to the external device connection unit, wherein the diagnostic result signal represents the result of the fault diagnosis performed by the diagnostic circuit. The diagnostic command signal includes one or more diagnostic commands. The diagnostic circuit is configured to perform the fault diagnosis in response to one or more diagnostic commands included in the diagnostic command signal. The external device connection portion includes: A power terminal is configured to receive power supplied from the battery pack to the motor in response to connection of the external device connection portion to the battery pack; and The signal terminal is configured to (i) form a communication path between the battery communication processing unit and the battery pack in response to the connection of the external device connection unit to the battery pack, and (ii) receive the diagnostic command signal from the diagnostic device and the diagnostic result signal from the result sending unit in response to the connection of the external device connection unit to the diagnostic device.

2. The electric work machine according to claim 1, characterized in that, It also has: The voltage detection unit is configured to detect the voltage of the battery pack that supplies power to the motor; A display panel is configured to display information about the electric work machine; and / or The trigger switch is configured to be operated by the user of the electric work machine. The diagnostic command signals include voltage detection diagnostic commands, display panel diagnostic commands, and / or trigger switch diagnostic commands. The diagnostic circuit is configured to diagnose the voltage detection unit, the display panel, and / or the trigger switch in response to one or more diagnostic commands included in the diagnostic command signal.

3. The electric work machine according to claim 2, characterized in that, The display panel has multiple LEDs. The diagnostic circuit is configured such that, in the fault diagnosis, (i) the plurality of LEDs are driven to make the display panel a preset display state, and then (ii) the display panel is diagnosed based on the magnitude of the current flowing through the plurality of LEDs.

4. The electric work machine according to claim 3, characterized in that, The preset display state corresponds to the situation where all of the multiple LEDs are lit or all of them are off.

5. The electric work machine according to claim 1, characterized in that, It also has: Multiple switching elements are configured to turn on or off the current flowing to the motor; A current detection circuit is configured to detect the magnitude of the current flowing through the motor; and / or A rotation sensor is configured to detect the rotational position of the motor. The diagnostic command signals include switching element diagnostic commands, current detection diagnostic commands, and / or rotation sensor diagnostic commands. The diagnostic circuit is configured to diagnose the plurality of switching elements, the current detection circuit, and / or the rotation sensor in response to one or more diagnostic commands included in the diagnostic command signal.

6. The electric work machine according to claim 5, characterized in that, The diagnostic circuit is configured to diagnose the plurality of switching elements, the current detection circuit, and the rotation sensor sequentially in the order of the plurality of switching elements, the current detection circuit, and the rotation sensor during the fault diagnosis.

7. The electric work machine according to claim 5, characterized in that, The diagnostic circuit is configured to: in response to the diagnostic command signal including the diagnostic element diagnostic command, (i) turn on at least one of the plurality of switching elements in an alternating manner each time, and then (ii) diagnose the plurality of switching elements based on the magnitude of the current detected by the current detection circuit.

8. The electric work machine according to claim 5, characterized in that, The diagnostic circuit is configured to: (i) supply the current to the motor via the plurality of switching elements in response to the current detection diagnostic command included in the diagnostic command signal, and then (ii) diagnose the current detection circuit based on the magnitude of the current detected by the current detection circuit.

9. The electric work machine according to claim 5, characterized in that, The diagnostic circuit is configured to: respond to the diagnostic command signal including the rotation sensor diagnostic command, (i) rotate the motor at a preset rotation speed, and then (ii) diagnose the rotation sensor based on the rotation position detected by the rotation sensor.

10. The electric work machine according to claim 1, characterized in that, It also has: A diagnostic device connection portion is configured to connect the diagnostic device; The first transmission path is configured to transmit the diagnostic command signal from the diagnostic device connection section to the command receiving section; and The second transmission path is configured to transmit the diagnostic result signal from the result sending unit to the diagnostic device connection unit.

11. The electric work machine according to claim 1, characterized in that, It also includes a wireless communication unit configured to communicate wirelessly with the diagnostic device. The instruction receiving unit is configured to receive the diagnostic instruction signal from the diagnostic device via the wireless communication unit. The result transmission unit is configured to transmit the diagnostic result signal to the diagnostic device via the wireless communication unit.

12. A field electrical system, characterized in that, have: The electric work machine according to any one of claims 1 to 11; and A diagnostic device configured to (i) send the diagnostic instruction signal to the electric work machine, and (ii) receive the diagnostic result signal from the electric work machine.

13. A method for diagnosing an electric work machine having a motor, a battery communication processing unit, a result transmission unit, and an external device connection unit, the method being characterized by comprising the following steps: The diagnostic device is connected to the external device connection point instead of the battery pack; The diagnostic device sends a diagnostic command signal to the electric work machine. In response to the electric work machine receiving the diagnostic command signal, fault diagnosis is performed on the electric work machine; and The result sending unit sends a diagnostic result signal, representing the result of the fault diagnosis, to the diagnostic device that is connected to the external device connection unit. The diagnostic command signal includes one or more diagnostic commands. The electric work machine performs the fault diagnosis in response to one or more diagnostic commands included in the diagnostic command signal. The external device connection is configured to selectively connect to either the diagnostic device or the battery pack. The external device connection portion includes: A power terminal is configured to receive power supplied from the battery pack to the motor in response to connection of the external device connection portion to the battery pack; and The signal terminal is configured to (i) form a communication path between the battery communication processing unit and the battery pack in response to the connection of the external device connection unit to the battery pack, and (ii) receive the diagnostic command signal from the diagnostic device and the diagnostic result signal from the result sending unit in response to the connection of the external device connection unit to the diagnostic device.

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