power tools

Abstract

To provide an electric power tool capable of executing FOTA while suppressing a decrease in work efficiency.SOLUTION: An electric power tool includes: an electric motor; a communication device; and a first control unit including a first storage section that stores a control program for driving the electric motor, a second storage section for storing an update program of the control program that is to be received by the communication device, and a processor configured to be able to drive the electric motor by executing the control program after the communication device starts reception of the update program.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to power tools.

Background Art

[0002] In recent years, a FOTA (Firmware Over-The-Air) technology that receives firmware by wireless communication and updates the firmware of an information terminal is known.

[0003] Patent Document 1 discloses an information terminal that determines whether FOTA can be executed based on the remaining battery level of a battery mounted on the information terminal.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the information terminal described in Patent Document 1 is configured to determine whether FOTA can be executed based on the remaining battery level of the battery, after the start of FOTA execution, it is not designed to consume the battery for purposes other than FOTA. Therefore, once FOTA is started, the user cannot use the information terminal until FOTA is completed. Therefore, when the firmware update method described in Patent Document 1 is applied to a power tool, once FOTA is started, the operator cannot use the power tool. As a result, the work efficiency is greatly reduced.

[0006] Therefore, an object of the present invention is to provide a power tool capable of executing FOTA while suppressing a decrease in work efficiency.

Means for Solving the Problems

[0007] This application discloses a power tool. The power tool comprises a first control unit comprising an electric motor, a communication device, a first storage unit for storing a control program for driving the electric motor, a second storage unit for storing an update program for the control program received by the communication device, and a processor configured to drive the electric motor by executing the control program after the communication device begins receiving the update program.

[0008] The electric motor is an electric motor that drives a tying unit that ties wires together, the control program is a control program that drives the electric motor to drive the tying unit, and the power tool may be a rebar tying machine configured to tie rebars together using the wires.

[0009] Furthermore, the power tool may be configured to be attachable to equipment. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view of a power tool according to one embodiment. [Figure 2] Figure 2 is a cross-sectional view of a power tool according to one embodiment. [Figure 3] Figure 3 is a block diagram showing the electrical circuit configuration of a power tool according to one embodiment. [Figure 4] Figure 4 is a block diagram illustrating the hardware configuration of a drive control unit and a communication control unit according to one embodiment. [Figure 5] Figure 5 is a flowchart showing the operation of a rebar tying machine during a firmware update. [Figure 6] Figure 6 shows the voltages of the first and second voltage lines in the operating mode of the rebar tying machine according to this embodiment. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are illustrative examples for explaining the present invention and are not intended to limit the present invention to these embodiments only.

[0012] For convenience, the left-right direction on the paper in Figure 2 is sometimes referred to as the front-back direction X (an example of the "first direction"), with the left direction being specifically called forward X1 and the right direction being called backward X2; the up-down direction on the paper is sometimes referred to as the up-down direction Z (an example of the "second direction"), with the top direction being specifically called upward Z1 and the bottom direction being called downward Z2; and the direction perpendicular to the front-back direction X and the up-down direction Z is sometimes referred to as the left-right direction Y (an example of the "third direction"), with the right direction being specifically called rightward Y1 and the left direction being called leftward Y2 when facing forward X1. These are used to explain relative directional relationships and do not indicate absolute directions.

[0013] The following describes embodiments of the present invention applied to a rebar tying machine, which is an electric power tool. Figure 1 is a perspective view of the rebar tying machine 10, which is an electric power tool according to this embodiment, and Figure 2 is a cross-sectional view of the rebar tying machine 10, obtained by cutting the electric power tool in a cross section perpendicular to the left-right direction Y.

[0014] However, the present invention is broadly applicable to power tools that have a communication function and perform work using an electric motor, such as drills, impact drivers, nailers, grinders, reciprocating saws, polishers, etc. The motor may be either a brushless motor or a brushed motor. The "power tool" of the present invention refers to a tool used for machining and other work that utilizes electricity as a power source. The "power tool" of the present invention includes not only products used individually, but also parts or modules that constitute part of other devices. For example, the "power tool" of the present invention may be a module attached to the equipment of a robot arm. Furthermore, the "power tool" of the present invention may be a part that constitutes part of a machine tool having multiple functions.

[0015] [First Embodiment] [Basic configuration of power tools] The rebar tying machine 10 according to this embodiment is configured to tie two or more rebars RB by feeding the wire W outward from the front end X1.

[0016] Specifically, the rebar tying machine 10 includes a handle 10H for the operator to grip, a magazine 10M for storing the wire W, a wire feeding unit 12 for feeding the wire W outward from the front end X1, a curl forming unit 14 that forms the wire W's path for winding the wire W around the rebar RB, a cutting unit 16 for cutting the wire W wrapped around the rebar RB, a tying unit 18 for twisting the wire W wrapped around the rebar RB, a tool control unit including a drive control unit 22 for controlling the feed motor 12M and tying motor 18M provided in the wire feeding unit 12 and the tying unit 18 respectively, and a communication unit 30 comprising a communication device 32 for the rebar tying machine 10 to communicate with external devices and a communication control unit 34 for controlling the communication device 32.

[0017] In the rebar tying machine 10 of this embodiment, the curl forming section 14, cutting section 16, tying section 18, tool control section, and communication section 30 constitute the main body 10B of the rebar tying machine 10. The magazine 10M is provided extending downward Z2 from the lower part of the front X1 of the main body 10B. The handle 10H is provided extending downward Z2 from the lower part of the rear X2 of the main body 10B. Therefore, the magazine 10M is provided in front X1 of the handle 10H, and the handle 10H is provided rear X2 of the magazine 10M. Furthermore, the lower part of the magazine 10M and the lower part of the handle 10H are connected. The following describes each component.

[0018] The rebar tying machine 10 is equipped with a handle 10H that extends downward Z2 from the main body 10B. The handle 10H corresponds to the part that the operator grips the rebar tying machine 10. The lower end of the handle 10H is formed to allow the main battery 10BP to be attached detachably. A trigger 10HT is provided on the front X1-facing side of the handle 10H. The rebar tying machine 10 is configured such that when the operator pushes the trigger 10HT backward X2, the tool control unit starts a control operation as described later, and the tying work begins.

[0019] The magazine 10M rotatably and removably houses a reel RL around which a linear wire W is wound. Here, the reel RL is configured to be able to feed one or a plurality of wires W simultaneously. The wire W is a linear body suitable for binding a long, malleable metal wire (including those covered) or other reinforcing bars RB.

[0020] The wire feeding unit 12 includes a pair of gears 12G configured to be able to advance the wire W by rotating in different directions while sandwiching the wire W, and a feeding motor 12M (an example of an "electric motor") that drives the gears 12G. The feeding motor 12M includes a rotor and a stator. The wire feeding unit 12 is configured to feed the wire W outward by rotating the rotor of the feeding motor 12M in the forward direction, and to be able to retract the wire W by rotating it in the reverse direction. The tool control unit for controlling the feeding motor 12M of the wire feeding unit 12 will be described later.

[0021] The curl forming unit 14 includes a curl guide 14A that curves the wire W sent by the wire feeding unit 12 to give it a curl, and a guide guide 14B for guiding the wire W with a curl formed by the curl guide 14A to the binding unit 18. The curl guide 14A is configured to be able to curve the wire W into a loop by advancing the wire W along the inner wall surface. Therefore, by feeding the wire W in a state where a plurality of reinforcing bars RB are arranged so as to extend in the left-right direction Y in the space between the curl guide 14A and the guide guide 14B, it becomes possible to wind the wire W around the reinforcing bars RB.

[0022] The cutting section 16 comprises a fixed blade, a movable blade that cuts the wire W in cooperation with the fixed blade, and a transmission mechanism 16A that transmits the operation of the binding section 18 to the movable blade. The cutting section 16 is configured to cut the wire W by the rotational movement of the movable blade with the fixed blade as the pivot axis. The transmission mechanism 16A transmits the operation of the binding section 18 to the movable blade and is configured to rotate the movable blade in conjunction with the binding operation of the binding section 18. Therefore, the transmission mechanism 16A is configured to cut the wire W at a predetermined timing, as will be described later, by rotating the movable blade in conjunction with the operation of the binding section 18.

[0023] The binding section 18 includes a pair of hooks 18H configured to be openable and closable for clamping the wire W, a rotating shaft for rotating the pair of hooks 18H with the front-rear direction X as the axis of rotation, and a reduction gear and a binding motor 18M configured to be rotatable with respect to the axis of rotation AX for moving the rotating shaft in the axis direction of rotation (front-rear direction X) and rotating the rotating shaft that has moved forward X1.

[0024] The rotating shaft of the binding section 18 rotates in the forward direction due to the forward rotation of the binding motor 18M. A sliding part is provided around the rotating shaft, and the sliding part is configured to move forward X1 as the rotating shaft rotates in the forward direction. When the pair of hooks 18H are open, the wire W fed out by the feed motor 12M proceeds curving along the inner wall surfaces of the curl guide 14A and the guide guide 14B, and is configured to pass through the gap between the open pair of hooks 18H at the tip of the wire W. In this state, when the binding motor 18M rotates in the forward direction and the rotating shaft rotates in the forward direction, the sliding part moves forward X1, and the pair of hooks 18H are configured to close. Thus, the pair of hooks 18H are configured to grip the wire W. Furthermore, when the binding motor 18M rotates in the forward direction and the rotating shaft rotates in the forward direction, causing the sliding part to move forward X1, the movable blade rotates due to the transmission mechanism 16A and cuts the wire W. As the binding motor 18M rotates in the forward direction, the binding section 18 bends the end of the cut wire W while the pair of hooks 18H grip the wire W. As the binding motor 18M rotates further in the forward direction, the rotating shaft is configured to rotate together with the sliding part with the front-rear direction X as the axis of rotation. As the rotating shaft rotates while the pair of hooks 18H grip the wire W, the pair of hooks 18H are configured to twist the wire W.

[0025] [Electrical circuit configuration] Figure 3 is a block diagram showing the electrical circuit configuration of the rebar tying machine 10 according to this embodiment. Of the electrical circuit configuration of the rebar tying machine 10, the configuration for controlling the feed motor 12M, the configuration for controlling the communication device 32, and the configuration for supplying power (voltage) to these configurations constitute the power supply device 40 of this embodiment.

[0026] Specifically, the power supply device 40 according to this embodiment includes a battery connection section 40CN for receiving power (voltage) from a battery 10BP (sometimes referred to as the "drive battery" or "first battery"), a power switch 40S for turning on or off the power (voltage) supply from the battery connection section 40CN, a first power control unit 41PC (an example of the "first voltage supply unit") that receives power (voltage) from the battery 10BP via the power switch 40S and supplies a first operating voltage for operating the drive control unit 22 (an example of the "first control unit") based on the first power supply voltage supplied from the battery 10BP, a drive control unit 22 that operates based on the first operating voltage and generates a control signal for controlling the feed motor 12M, and a motor control unit 24 that controls the current flowing to the stator of the feed motor 12M based on the control signal generated by the drive control unit 22.

[0027] The battery 10BP is configured to supply power to operate at least the drive control unit 22, motor control unit 24, feed motor 12M and binding motor 18M, the communication control unit 34 (described later), the wireless communication device 32 and the position information acquisition unit 36. The battery 10BP is, for example, a rechargeable lithium-ion secondary battery and has a predetermined rated capacity, rated voltage and rated current. For example, the battery 10BP has a rated capacity of 5.0Ah and is configured to supply a DC voltage with a rating of 14.4V. However, as will be described later, the DC voltage supplied from the battery 10BP gradually decreases as the battery 10BP consumes power.

[0028] The battery connection section 40CN receives a DC voltage from the battery 10BP and supplies it to the first power control unit 41PC. The power supply unit 40 includes a first voltage line 41 connecting the battery connection section 40CN and the first power control unit 41PC, and the DC first power supply voltage supplied from the battery 10BP is applied to this first voltage line 41.

[0029] The power switch 40S turns on or off the supply of power (voltage) from the battery 10BP to the first power control unit 41PC via the battery connection part 40CN, in accordance with the operation of the main power switch (not shown) of the rebar tying machine 10. Therefore, when the operator turns off the main power switch, the power switch 40S cuts off the supply of power (voltage) from the battery 10BP to the first power control unit 41PC, and when the operator turns it on, the power switch 40S allows the supply of power (voltage) from the battery 10BP to the first power control unit 41PC.

[0030] The first power control unit 41PC generates voltages to operate each circuit element, including the drive control unit 22, based on the first power supply voltage supplied from the battery 10BP, and supplies these voltages to each circuit element. For example, it generates a voltage of 3.3V (an example of the "first operating voltage"), which is the operating voltage of the drive control unit 22, based on the first power supply voltage of 14.4V supplied from the battery 10BP, and supplies it to the drive control unit 22. It is also configured to supply the first power supply voltage (14.4V) directly to the motor control unit 24, the motor control unit 26, and the stators of each motor. Here, supplying voltage includes generating and supplying voltage, and supplying voltage directly without generating voltage. The first power control unit 41PC is configured to further generate an intermediate voltage that is greater than the first operating voltage and less than the first power supply voltage, and supply it to different circuit elements. The first power control unit 41PC may also include a boost circuit that generates a voltage greater than the first power supply voltage and supplies it to different circuit elements.

[0031] The drive control unit 22 operates based on a voltage of, for example, 3.3V, generates a control signal to control the feed motor 12M, and supplies it to the motor control unit 24. The drive control unit 22 is also configured to control other actuators of the rebar tying machine 10. Furthermore, the drive control unit 22 supplies the first power supply voltage supplied from the first power control unit 41PC to the motor control unit 24 (for example, the positive power line). The drive control unit 22 is also configured to receive a signal that detects when the trigger 10HT is pressed and to start the motor control operation based on this. In addition, the drive control unit 22 may be configured to receive a signal from the thermistor indicating the temperature of the power tool (rebar tying machine 10) and to control the feed motor 12M based on this. For example, the drive control unit 22 may generate different control signals and supply them to the motor control unit 24 depending on whether the power tool is relatively hot or cold.

[0032] Figure 4 is a block diagram illustrating the hardware configuration of the drive control unit 22 and the communication control unit 34. The drive control unit 22 comprises one or more processors 22P implemented by integrated circuits (ICs), a non-volatile memory 22NVM that stores information non-transitoryly and stores firmware containing computer instructions that execute each of the processes described in this embodiment, and a volatile memory 22VM that temporarily stores information in order to execute each of the processes described in this embodiment. The non-volatile memory 22NVM is composed of, for example, NOR-type and / or NAND-type flash memory. The volatile memory 22VM is composed of, for example, SRAM and DRAM.

[0033] The firmware includes a control program for generating control commands to drive the feed motor 12M and the bundling motor 18M, respectively, as shown in this embodiment.

[0034] The non-volatile memory 22NVM has multiple divided storage areas. One of the storage areas of the non-volatile memory 22NVM, the first storage unit NVM1, stores the control programs for the feed motor 12M and the bundling motor 18M.

[0035] The non-volatile memory 22NVM further includes a second memory unit NVM2 as one of its memory areas for storing update programs for the control programs of the feed motor 12M and the binding motor 18M. When the rebar tying machine 10 is used for the first time, the second memory unit NVM2 stores the same information (control programs for the feed motor 12M and the binding motor 18M). However, when the rebar tying machine 10 is used for the first time, the second memory unit NVM2 does not need to store any information.

[0036] Such a drive control unit 22 may be implemented using an IC called an ASIC, FPGA, or microcontroller. The drive control unit 22 also functions as part of the tool control unit. The motor control unit 24 controls the current flowing to the stator of the feed motor 12M based on the control signal generated by the drive control unit 22. For example, the motor control unit 24 may include a plurality of semiconductor elements (e.g., 6) connected in a three-phase bridge between a positive power line and a negative ground (reference potential) power line, and a driver circuit for generating and supplying a gate signal (or base signal) to the gate (or base) of each semiconductor element.

[0037] In this embodiment, the feed motor 12M comprises, for example, a stator consisting of three-phase windings connected to the three-phase output of the motor control unit 24, and a rotor configured to rotate in either the forward or reverse direction according to the rotating magnetic field generated by the flow of current through the windings of the stator. The feed motor 12M further includes, for example, a Hall element for detecting the position of the rotor, and the drive control unit 22 may be configured to receive a position signal from the Hall element and generate a control signal based on it.

[0038] Similarly, the power supply unit 40 also includes a drive control unit that generates a control signal for controlling the bundling motor 18M and supplies it to the motor control unit 26 of the bundling motor 18M, and a motor control unit 26 that controls the current flowing to the stator of the bundling motor 18M based on the control signal generated by the drive control unit. The drive control unit for the bundling motor 18M and the drive control unit 22 for the feed motor 12M may be configured to be provided on the same semiconductor chip.

[0039] The power supply unit 40 further includes a first wiring board 41PCB on which at least a first power control unit 41PC, a drive control unit 22, a motor control unit 24, and a motor control unit 26 are mounted. The first wiring board 41PCB is provided with a first connection part 41CN (an example of a "first connector") for connecting to a second wiring board 42PCB, which will be described later, via a cable 40CB. As shown in Figure 3, the first voltage line 41 includes a first wiring part 41A that connects the battery connection part 40CN and the first power control unit 41PC, and a second wiring part 41B that branches off from the first wiring part 41A and connects to the first connection part 41CN. Furthermore, the power supply unit 40 is configured to be able to receive a first operating voltage (3.3V) generated by the first power control unit 41PC, and includes a second voltage line 42 that connects the first power control unit 41PC and the first connection part 41CN. In Figure 3, the first wiring board 41PCB is depicted conceptually, but the actual first wiring board 41PCB is formed in a rectangular shape with two parallel long sides and two parallel short sides connecting the ends of the long sides.

[0040] With the above configuration, it becomes possible to supply the power necessary to realize the functions of the power tool. Next, we will explain the configuration related to the communication function of the power tool.

[0041] [Communication function] As also shown in Figure 3, the power supply unit 40 includes a second battery 42BP for communication (sometimes called the "communication battery"), a second power control unit 42PC (an example of a "second voltage supply unit") configured to supply a second operating voltage for operating the communication control unit 34 (sometimes called the "second control unit") based on a first power supply voltage supplied from the main battery 10BP, and also configured to supply a second operating voltage for operating the communication control unit 34 based on a second power supply voltage supplied from the second battery 42BP when the main battery 10BP is disconnected, etc., and a communication control unit 34 that controls the wireless communication device 32 (an example of a "communication device 32") and the location information acquisition unit 36 ​​based on the second operating voltage supplied from the second power control unit 42PC.

[0042] Furthermore, the power tool includes a communication unit 30 which comprises a location information acquisition unit 36 ​​that acquires location information of the power tool and supplies it to a communication control unit 34, and a wireless communication device 32 for wirelessly transmitting and receiving information with external devices.

[0043] The location information acquisition unit 36 ​​includes, for example, an antenna configured to receive signals from GPS (or GLONASS or other GNSS) positioning satellites, and a receiving circuit that acquires location information of the power tool based on the signals received by the antenna.

[0044] The wireless communication device 32 includes, for example, an antenna configured to send and receive information with a remote base station using a licensed band or unlicensed band frequency band based on LPWA technology and according to a predetermined standard; an RFIC that demodulates the analog signal received by the antenna and supplies it to a baseband IC, and modulates the signal supplied from the baseband IC into an analog signal for transmission from the antenna; and a baseband IC that decodes or encodes the signal acquired from the RFIC according to a protocol specified in the standard to send and receive information. The communication device 32 may also support short-range wireless communication methods such as Bluetooth (registered trademark) or wireless LAN.

[0045] With the above configuration, the communication control unit 34 is configured to provide the location information of the power tool to an external device by, for example, transmitting the location information acquired by the location information acquisition unit 36 ​​from the antenna of the communication device 32. In this embodiment, the communication control unit 34, the RFIC, and the baseband IC may be stacked in the same semiconductor package. Alternatively, the communication control unit 34 and the baseband IC may be composed of the same semiconductor chip.

[0046] As shown in Figure 4, the communication control unit 34 comprises one or more processors 34P implemented by integrated circuits (ICs), a non-volatile memory 34NVM that stores information non-transitoryly, storing firmware including computer instructions that execute the communication control processing described in this embodiment, and a volatile memory 34VM that temporarily stores information in order to execute each of the processes described in this embodiment. The non-volatile memory 34NVM is composed of, for example, NOR-type or NAND-type flash memory. The volatile memory 34VM is composed of, for example, SRAM and DRAM.

[0047] As shown in the figure, the drive control unit 22 and the communication control unit 34 are connected by a bus via the connection part of the first wiring board 41PCB, the cable 40CB, and the connection part of the second wiring board 42PCB, and are configured to send and receive information from each other. Therefore, the communication control unit 34 can transmit information received by the communication device 32 to the drive control unit 22, and the drive control unit 22 is configured to control the feed motor 12M and the bundling motor 18M based on the information received from the communication device 32. In addition, the drive control unit 22 can transmit information obtained from the actuators and sensors of the power tool, such as the feed motor 12M and the bundling motor 18M, to the communication control unit 34, and the communication control unit 34 can transmit the information received from the drive control unit 22 to external devices using the communication device 32.

[0048] Furthermore, the power supply unit 40 includes a second wiring board 42PCB on which at least a second power control unit 42PC, a communication control unit 34, a communication device 32, and a location information acquisition unit 36 ​​are mounted. The second wiring board 42PCB is provided with a second connection part 42CN (an example of a "second connector") for connecting to the first wiring board 41PCB via a cable 40CB. As shown in Figure 3, the first wiring part 41A and the second wiring part 41B of the first voltage line 41 are formed on the first wiring board 41PCB, while the third wiring part 41C, which is electrically connected to the first wiring part 41A and the second wiring part 41B via a connector, is formed on the second wiring board 42PCB. Also, the wiring part connecting the first connection part 41CN of the second voltage line 42 to the first power control unit 41PC is formed on the first wiring board 41PCB, while the wiring part that is electrically connected to this wiring part via a connector and connects to the second power control unit 42PC is formed on the second wiring board 42PCB.

[0049] The second battery 42BP, further provided by the power supply unit 40, supplies power to operate at least the communication control unit 34, the wireless communication device 32, and the location information acquisition unit 36. The second battery 42BP is, for example, a rechargeable lithium-ion secondary battery and has a predetermined rated capacity, rated voltage, and rated current. For example, the second battery 42BP has a smaller rated capacity than the main battery 10BP and is configured to supply a DC voltage with a rating of 3.6V (an example of the "second power supply voltage"). In addition, since the second battery 42BP is housed in the casing that constitutes the main body 10B of the power tool, unlike the main battery 10BP, it is not provided to be easily detachable and is fixed integrally with the second wiring board 42PCB. Note that the second battery 42BP does not have to be fixed integrally with the second wiring board 42PCB, and may, for example, be provided to be detachable from the second wiring board 42PCB.

[0050] The second power control unit 42PC is configured to generate and supply voltages to each circuit element, including the communication control unit 34 and the drive control unit 22, based on the power supply voltage supplied from the battery 10BP. For example, based on the 14.4V power supply voltage supplied from the battery 10BP, it generates a voltage of 3.3V (an example of a "second operating voltage") which is the operating voltage for the communication control unit 34, and supplies it to the communication control unit 34 via the third voltage line 43 connecting the second power control unit 42PC and the communication control unit 34. It also generates a predetermined operating voltage and supplies it to the position information acquisition unit 36 ​​and the wireless communication unit 30.

[0051] In addition, the second power control unit 42PC is configured to generate an operating voltage for operating each circuit element, etc., based on a DC voltage of 3.6V corresponding to the second power supply voltage supplied from the second battery 42BP, and to supply this voltage to each circuit element, etc., including the communication control unit 34 and the drive control unit 22. Here, the second power control unit 42PC is equipped with a boost circuit capable of generating a voltage higher than the second power supply voltage in order to operate the antenna. However, the rebar tying machine 10 does not necessarily have to be equipped with a boost circuit. In this embodiment, since the operating voltage of the antenna is higher than the second power supply voltage, the rebar tying machine 10 is equipped with a boost circuit such as a charge pump circuit. However, for example, if the circuit elements are selected so that the operating voltage of the circuit elements driven by the power of the second battery 42BP is less than or equal to the second power supply voltage, or if the second power supply voltage is set, the rebar tying machine 10 does not necessarily have to be equipped with a boost circuit.

[0052] With the above configuration, when the main battery 10BP is removed, the second power control unit 42PC is configured to operate the drive control unit 22, communication control unit 34, location information acquisition unit 36, and wireless communication unit 30 based on the second power supply voltage supplied from the second battery 42BP, thereby enabling wireless transmission and reception of information with external devices. Accordingly, even when the main battery 10BP is removed, the communication control unit 34 is configured to provide the location information of the power tool to external devices by transmitting the location information acquired by the location information acquisition unit 36 ​​via the wireless communication unit 30. Furthermore, as will be described later, the communication control unit 34 is configured to store, for example, a non-volatile semiconductor memory constituting the drive control unit 22, an update program for updating the firmware of the drive control unit 22 received via the wireless communication unit 30.

[0053] Furthermore, the second power control unit 42PC generates a charging voltage for charging the second battery 42BP based on the power supply voltage supplied from the main battery 10BP, and is configured to enable charging of the second battery 42BP. Accordingly, when the battery 10BP is installed, the power supply unit 40 according to this embodiment is configured to operate the drive control unit 22, motor control unit 24 and motor control unit 26, motors (feed motor 12M and binding motor 18M), communication control unit 34, position information acquisition unit 36 ​​and wireless communication unit 30, and to enable charging of the second battery 42BP, based on the power supplied from the battery 10BP. When the main battery 10BP is removed, the power supply unit 40 is configured to operate the drive control unit 22, communication control unit 34, position information acquisition unit 36 ​​and wireless communication unit 30 based on the power supplied from the second battery 42BP. As mentioned above, supplying voltage includes supplying it directly by passing it through without generating any voltage. Therefore, the voltage that serves as the power supply may be supplied to the communication control unit 34, etc., by directly connecting the wiring to which the output voltage from the second battery 42BP is applied to the power terminals of the communication control unit 34, etc., or the voltage that serves as the power supply may be supplied to the drive control unit 22, etc., by directly connecting the wiring to which the output voltage from the second power control unit 42PC is applied to the power terminals of the drive control unit 22, etc.

[0054] The power supply unit 40 further includes a second wiring board 42PCB on which at least a second power control unit 42PC, a communication control unit 34, a location information acquisition unit 36, and a wireless communication unit 30 are mounted. The second wiring board 42PCB is provided with a second connection part 42CN (an example of a "second connector") for connecting to the first wiring board 41PCB via a cable 40CB.

[0055] As shown in Figure 3, the first voltage line 41 to which the power supply voltage from the battery 10BP is applied not only supplies voltage to the first power control unit 41PC via the power switch 40S, but also supplies voltage to the second power control unit 42PC by providing wiring that connects to the first connection part 41CN of the first wiring board 41PCB, the cable 40CB, and the second connection part 42CN of the second wiring board 42PCB.

[0056] Furthermore, the second voltage line 42 to which the first operating voltage (3.3V) generated by the first power control unit 41PC is applied includes a wiring section connected to the second power control unit 42PC and the communication control unit 34 via the connection section of the first wiring board 41PCB, the cable 40CB, and the connection section of the second wiring board 42PCB. This configuration allows power (voltage and current) to be supplied from the first power control unit 41PC to the second power control unit 42PC when the main battery 10BP is installed, while allowing power (voltage and current) to be supplied from the second power control unit 42PC to the first power control unit 41PC when the main battery 10BP is removed.

[0057] Here, in the third wiring section 41C of the first voltage line 41, which is provided on the second wiring board 42PCB, a circuit is provided that allows current to flow from the first power control unit 41PC to the second power control unit 42PC and prevents current from flowing from the second power control unit 42PC to the first power control unit 41PC. For example, a diode (an example of a "reverse current prevention circuit") is provided, in which the anode is connected to the first power control unit 41PC and the cathode is connected to the second power control unit 42PC. Note that the reverse current prevention circuit may also be provided in the second wiring section 41B of the first voltage line 41, which is provided on the first wiring board 41PCB.

[0058] By providing a reverse current prevention circuit, it is possible to suppress the flow from the second battery 42BP to the first power control unit 41PC via the second power control unit 42PC, thereby enabling effective use of both the main battery 10BP and the second battery 42BP.

[0059] Preferably, the second voltage line 42 is configured to allow current to flow from the first power control unit 41PC (first voltage supply unit) to the second power control unit 42PC (second voltage supply unit), and also to allow current to flow from the second power control unit 42PC (second voltage supply unit) to the first power control unit 41PC (first voltage supply unit).

[0060] With this configuration, it becomes possible to supply power (voltage) to the power terminal of the drive control unit 22 of the first wiring board 41PCB via the second voltage line 42 that connects the second wiring board 42PCB, which is a communication board, the second connector, the first connector, and the first power control unit 41PC.

[0061] Therefore, the drive control unit 22 can be operated even when the main battery 10BP is removed. For example, as will be described later, the drive control unit 22 can perform tasks such as updating the firmware, which is the control program. As a result, the operator can avoid having to interrupt their work to update the firmware of the drive control unit 22, thereby improving work efficiency.

[0062] The second voltage line 42 may be provided to connect the first connector directly to the power terminal of the drive control unit 22 of the first wiring board 41PCB, without going through the first power control unit 41PC.

[0063] [Operation of the rebar tying machine]

[0064] The operation of the rebar tying machine 10, including its operation during firmware updates, will be described below. Figure 5 is a flowchart showing the operation of the rebar tying machine 10 during firmware updates. Figure 6 is a graph showing the voltage state during each operation of the rebar tying machine 10. The rebar tying machine 10 according to this embodiment is configured to be able to execute each of the operation modes described below.

[0065] Figure 6 also shows the power supply status from the second battery 42BP to the circuit elements on the first wiring board 41PCB. When power is supplied from the second battery 42BP to the circuit elements on the first wiring board 41PCB, the power graph in Figure 6 shows a negative value. At this time, a current flows from the second wiring board 42PCB to the first wiring board 41PCB in the wiring section of the second voltage line 42 that connects the first wiring board 41PCB and the second wiring board 42PCB, and the second battery 42BP supplies power to the circuit elements on the first wiring board 41PCB.

[0066] On the other hand, when power is supplied from the first battery to the circuit elements on the second wiring board 42PCB, the power graph in Figure 6 shows a positive value. At this time, a current flows from the first wiring board 41PCB to the second wiring board 42PCB in at least one of the wiring sections of the first voltage line 41 connecting the first wiring board 41PCB and the second wiring board 42PCB, and the first battery supplies power to the circuit elements on the second wiring board 42PCB.

[0067] When no power is supplied from the first battery to the circuit elements on the second wiring board 42PCB, and no power is supplied from the second battery 42BP to the circuit elements on the first wiring board 41PCB, the power graph in Figure 4 shows zero. At this time, no current flows in either the wiring section of the first voltage line 41 connecting the first wiring board 41PCB and the second wiring board 42PCB, or the wiring section of the second voltage line 42 connecting the first wiring board 41PCB and the second wiring board 42PCB.

[0068] However, the rebar tying machine 10 can perform each operating mode in any order. Furthermore, the power tool of the present invention may be configured to perform any one of the operating modes described below, or it may be configured to perform any two or more of the operating modes described below.

[0069] [Battery removed or power switch 40S is off] After completing the work, the worker removes the main battery 10BP from the lower end of the handle 10H or turns off the power switch 40S (step S10). When the main battery 10BP is removed or the power switch 40S is off, the motors of the rebar tying machine 10 (feed motor 12M and tying motor 18M) are inactive and in a non-operating state. At this time, the communication device 32 of the rebar tying machine 10, which is a power tool, uses the sub-second battery 42BP as its power source to perform communication (step S12). Note that the following operations can also be performed with power tools other than the rebar tying machine 10, so below, the rebar tying machine 10 may be simply referred to as a power tool.

[0070] In Figure 6, the time intervals t0 to t1 correspond to the operating mode in which the electric motor and drive control unit 22 of the power tool are in a non-operating state and the communication device 32 is in an operating state. At this time, no DC voltage is applied to the first voltage line 41 from the first battery, so the first voltage line 41 is 0V (ground level) and no current flows through the first voltage line 41. Also, since there is no need to operate the circuit elements on the first wiring board 41 PCB, including the drive control unit 22, the second voltage line 42 is also 0V (ground level) and no current flows through the second voltage line 42. Furthermore, since no power is supplied from the first battery to the circuit elements on the second wiring board 42 PCB, and no power is supplied from the second battery 42BP to the circuit elements on the first wiring board 41 PCB, the power graph shows zero.

[0071] At this time, the second battery 42BP supplies a second power supply voltage of 3.6V to the second power control unit 42PC. The second power supply unit generates an operating voltage for operating each circuit element of the communication unit 30 based on a DC voltage of 3.6V corresponding to the second power supply voltage supplied from the second battery 42BP, and applies the operating voltage (3.3V) of the communication control unit 34 to the third voltage line 43. Similarly, the second power control unit 42PC generates an operating voltage for operating each circuit element of the communication unit 30, such as the antenna, and supplies it to each circuit element, including the communication control unit 34 and the drive control unit 22. For this reason, the communication unit 30 is configured to be operable.

[0072] With the above configuration, even when the main battery 10BP is removed, the power tool is configured to provide its location information to the outside world by transmitting the location information acquired by the location information acquisition unit 36 ​​via the wireless communication unit 30. Therefore, even if the power tool is stolen, it is possible to obtain the location information of the power tool.

[0073] [Firmware update] The power tool performs a firmware update triggered by a predetermined event (step S14). For example, when the communication unit 30 of the power tool receives a firmware update command from an external device, the power tool starts the firmware update process. Specifically, the processor 34P of the communication control unit 34 starts receiving firmware update programs using the communication device 32 (step S14). Once the communication device 32 starts receiving update programs, the processor 34P of the communication control unit 34 sequentially stores the received update programs in the volatile memory 34VM.

[0074] The processor 22P of the drive control unit 22 (or the processor 34P of the communication control unit 34) accesses the volatile memory 34VM via the bus and sequentially updates or stores the update program in the second storage unit NVM2 (step S16).

[0075] In Figure 6, times t1 to t2 correspond to the operating mode when the power tool is performing a firmware update process. At this time, the motor of the power tool is in a non-operating state, while the drive control unit 22 and the communication unit 32 are in an operating state. At this time, no DC voltage from the first battery is applied to the first voltage line 41, so the first voltage line 41 is 0V (ground level) and no current flows through the first voltage line 41. On the other hand, the second power control unit 42PC applies the operating voltage of the drive control unit 22 (3.3V) to the second voltage line 42 based on the second power supply voltage supplied from the second battery 42BP. Similarly, the second power control unit 42PC applies the operating voltage of the communication control unit 34 (3.3V) to the third voltage line 43 based on the second power supply voltage supplied from the second battery 42BP. Similarly, the second power control unit 42PC generates operating voltages to operate each circuit element such as the antenna of the communication unit 30 and supplies them to each circuit element including the communication control unit 34 and the drive control unit 22. At this time, power is supplied from the second battery 42BP to the drive control unit 22, which is a circuit element on the first wiring board 41PCB. Therefore, the power graph shows a negative value, and current flows in the wiring section of the second voltage line 42 connecting the first wiring board 41PCB and the second wiring board 42PCB, in the direction from the second wiring board 42PCB to the first wiring board 41PCB. For this reason, the drive control unit 22 and the communication unit 30 are configured to operate.

[0076] With the above configuration, the power tool is configured to receive firmware update programs, which are the control programs for the drive control unit 22, via the communication unit 30, even when the main battery 10BP is disconnected or the power switch 40S is turned off. The drive control unit 22 then stores the update programs in the second storage unit NVM2 (including updating already stored data), and the firmware can be updated based on the update programs. This makes it possible to update the firmware while the operator is not working. Consequently, work efficiency can be improved.

[0077] [Install the battery or turn on the power switch 40S] When starting work, the operator attaches the main battery 10BP to the lower end of the handle 10H or turns on the power switch 40S (step S18). At this time, if the communication device 32 has finished receiving the entire update program and the entire update program is stored in the second memory NVM2, the processor 22P of the drive control unit 22 executes the update program stored in the second memory NVM2 instead of the control program stored in the first memory NVM1, and drives the electric motors (feed motor 12M and binding motor 18M) based on the update program.

[0078] On the other hand, there are cases where an operator starts work before the communication device 32 has finished receiving the entire update program. Specifically, this occurs when the operator turns on the power switch 40S and starts work. In this case, the processor 22P of the drive control unit 22 is configured to drive the electric motors (feed motor 12M and binding motor 18M) based on the control program stored in the first memory unit NVM1 (step S20).

[0079] By providing the non-volatile memory 22NVM with two memory units, the first memory unit NVM1 and the second memory unit NVM2, the operator does not need to wait until FOTA is complete before starting work. Therefore, it is possible to improve work efficiency. From time t2 onwards in Figure 6, the main battery 10BP is installed, and the electric motor, drive control unit 22, and communication device 32 of the power tool are in operation mode. This operation mode starts when the operator turns on the power switch 40S to start work. At this time, a DC voltage from the first battery is applied to the first voltage line 41, so the first voltage line 41 is 14.4V. When the operator presses the trigger 10HT in this state, the motors (binding motor 18M and feed motor 12M) start to drive, and current flows from the first wiring section 41A of the first voltage line 41 to the motor stator via the first power control unit 41PC.

[0080] Furthermore, the first battery is configured to supply power to the communication unit 30. Specifically, the first power supply unit is configured to generate a 3.3V operating voltage for the communication control unit 34 based on a 14.4V DC voltage corresponding to the first power supply voltage supplied from the first battery, and to supply this voltage to the communication control unit 34 via the second voltage line 42.

[0081] In addition, if the charge level of the second battery 42BP is low, the first battery is configured to be able to charge the second battery 42BP. Specifically, the second power supply unit is configured to generate a charging voltage for charging the second battery 42BP based on a DC voltage of 14.4V corresponding to the first power supply voltage supplied from the first battery, and to be able to charge the second battery 42BP.

[0082] At this time, power is supplied from the first battery to the communication unit 30 on the second wiring board 42PCB and the second battery 42BP, so the power graph shows a positive value, and current flows in the wiring sections of the first voltage line 41 and the second voltage line 42 that connect the first wiring board 41PCB and the second wiring board 42PCB, respectively, in the direction from the second wiring board 42PCB to the first wiring board 41PCB.

[0083] Here, a diode (an example of a "reverse current prevention circuit") is provided in the third wiring section 41C of the first voltage line 41. This configuration prevents the situation where, when power is supplied from the first battery 10BP to the motor to drive the motor, the power from the second battery 42BP is unintentionally consumed to drive the motor.

[0084] After the work is completed, when the main battery 10BP is removed from the lower end of the handle 10H or the power switch 40S is turned off, the power tool resumes receiving and storing update programs using the second battery 42BP as its power source (step S22). If part of the update program is already stored in the second memory unit NVM2, the remaining update program is received and stored in the second memory unit NVM2. Alternatively, even if part of the update program is already stored in the second memory unit NVM2, the update program may be received again from the beginning and stored in the second memory unit NVM2.

[0085] In other words, according to the power tool of this embodiment, the processor 22P receives and stores part of the update program using the second battery after the first battery is removed from the main body of the power tool or the power switch 40S is turned off. Subsequently, the processor 22P stops receiving the update program after the first battery is attached to the main body of the power tool or the power switch 40S is turned on. The processor 22P is configured to be able to execute the original control program even after it has started receiving the update program. Furthermore, the processor 22 is configured to receive and store the remainder (another part) or all of the update program using the second battery after the first battery is again removed from the main body of the power tool or the power switch 40S is turned off.

[0086] With this configuration, FOTA is performed when the main battery 10BP is removed or the power switch 40S is turned off, thus improving work efficiency according to the power tool of this embodiment. The power tool of this embodiment can be modified as appropriate within the range of the ordinary creative ability of those skilled in the art. For example, the present invention can be applied to power tools other than rebar tying machines.

[0087] Furthermore, the non-volatile memory 22NVM and the non-volatile memory 34NVM may be shared. Similarly, the volatile memory 22VM and the volatile memory 34VM may be shared. Also, the first storage unit NVM1 and the second storage unit NVM2 may be provided on separate semiconductor chips, or they may be provided in different regions (blocks) within the same semiconductor chip.

[0088] [Second Embodiment] The following describes the power tool according to this embodiment. Points that are identical or similar to those in other embodiments will be given the same or similar names or reference numerals, and their descriptions will be omitted or simplified; the focus will be on the differences. The rebar tying machine (an example of a "power tool") according to this embodiment is configured to perform work using a power tool by controlling the drive of the motors (tying motor 18M and feed motor 12M) while receiving updates for the control program.

[0089] First, the operator attaches the main battery 10BP to the lower end of the handle 10H, or turns on the power switch 40S of the rebar tying machine 10 to which the battery 10BP is attached, and begins working with the rebar tying machine 10. At this time, a DC voltage from the first battery is applied to the first voltage line 41, so the first voltage line 41 is 14.4V. When the operator presses the trigger 10HT in this state, the drive control unit 22 starts driving control of the motors (tying motor 18M and feed motor 12M). Simultaneously, the main battery 10BP supplies power to the communication unit 30. Specifically, the first power supply unit generates a 3.3V operating voltage for the communication control unit 34 based on a 14.4V DC voltage corresponding to the first power supply voltage supplied from the battery 10BP, and is configured to supply this voltage to the communication control unit 34 via the second voltage line 42. Consequently, the communication control unit 34 starts controlling the communication device 32 and receives firmware update programs.

[0090] Therefore, the rebar tying device 10 is configured so that the communication device 32 can receive firmware update programs while the motors (tying motor 18M and feed motor 12M) are running. When the communication device 32 begins receiving update programs, the processor 34P of the communication control unit 34 sequentially stores the received update programs in the volatile memory 34VM. Next, the processor 22P of the drive control unit 22 or the processor 34P of the communication control unit 34 accesses the volatile memory 34VM via the bus and sequentially stores the update program in the second storage unit NVM2. When the processor 34P of the communication control unit 34 stores the update program in the second storage unit NVM2, it is possible to suppress interference with the motor control by the drive control unit 22.

[0091] Even after the update program is stored, the drive control unit 22 controls the motors (binding motor 18M and feed motor 12M) based on the control program before the update. After completing their work, the operator should either remove the main battery 10BP from the lower end of the handle 10H, or turn off the power switch 40S. However, for short breaks, the operator may leave the battery 10BP installed and turn off the power switch 40S. When starting work, the operator attaches the main battery 10BP to the lower end of the handle 10H or turns on the power switch 40S. At this time, if the communication device 32 has finished receiving the entire update program and the entire update program is stored in the second memory NVM2, the processor 22P of the drive control unit 22 executes the update program stored in the second memory NVM2, rather than the control program stored in the first memory NVM1, and drives the electric motors (feed motor 12M and binding motor 18M) based on the update program. As described above, the power tool according to this embodiment allows for the reception and updating of update programs even while working with the electric motor. Furthermore, since the operator does not need to wait for FOTA to complete before starting work, work efficiency can be improved.

[0092] [Third Embodiment] The following describes the power tool according to this embodiment. Note that components identical or similar to those in other embodiments will be given the same or similar names or reference numerals, and their descriptions will be omitted or simplified; the focus will be on the differences.

[0093] The rebar tying device according to this embodiment (an example of a "power tool") is configured to be attachable to a robot arm (an example of "equipment"). Furthermore, the tying device is configured to receive a DC power supply from the robot arm. Therefore, unlike the first embodiment, the tying device according to this embodiment does not have a handle or a battery attachment / detachment part.

[0094] Furthermore, the binding device according to this embodiment is configured to simultaneously receive update programs via a communication device, store the update programs in a second storage unit, and execute a control program using a control processor. As a result, the binding device can perform FOTA (Forward-Oriented Tying) while driving an electric motor to tie reinforcing bars, thereby improving work efficiency.

[0095] Thus, with the bundling device according to this embodiment, by providing two storage units, a first storage unit and a second storage unit, in the non-volatile memory, it is not necessary to wait for the completion of FOTA before starting work. Therefore, it is possible to improve work efficiency.

[0096] The present invention is subject to various modifications without departing from its essence. For example, within the ordinary creative capacity of those skilled in the art, other known elemental technologies can be added to some components of a certain embodiment. Also, some components of a certain embodiment can be replaced with other known elemental technologies. For example, the drive control unit and the communication control unit can operate at different voltages. Furthermore, the update program is not limited to an update program for updating the entire control program. For example, the update program may be an update program (module) for updating some modules of the control program, or some control data. Moreover, the update program may be an update program relating to additional functions added to the control program. [Explanation of Symbols]

[0097] 10. Rebar tying machine (power tool) 10H handle 10HT Trigger 10M Magazine 10B Main Unit 10BP Battery (Battery Pack, Battery No. 1) 12 Wire feeding section 12G Gear 12M Feed Motor (Electric Motor) 14. Curl-forming section 14A Curl Guide 14B Guidance Guide 16 Cut section 16A Transmission Mechanism 18 Binding section 18H Hook 18M Binding Motor (Electric Motor) 22 Drive control unit (first control unit) 22P processor 22NVM Non-Volatile Memory NVM1 1st memory NVM2 2nd storage 22VM volatile memory 24 Motor Control Unit 30 Communications Department 32 Communications equipment 34P processor 34NVM Non-Volatile Memory 34VM volatile memory 34 Communication Control Unit 36 Location information acquisition section 40 Power supply 40CB Cable 40CN Battery connector 40D diode (reverse current protection circuit) 40S Power Switch 41. First voltage line 41A 1st wiring section 41B 2nd wiring section 41C 3rd wiring section 41PCB First Wiring Board 41PC First Power Control Unit (First Voltage Supply Unit) 41CN First connection section (first connector) 42 Second voltage line 42BP 2nd Battery 42CN Second connection section (second connector) 42PC Second Power Control Unit (Second Voltage Supply Unit) 42PCB Second Wiring Board 43 Third voltage line RL Reel W wire RB rebar

Claims

1. Electric motor and, Communication equipment, A first control unit comprising: a first storage unit for storing a control program for driving the electric motor; a second storage unit for storing an update program for the control program received by the communication device; and a processor configured to drive the electric motor by executing the control program after the communication device begins receiving the update program. First battery and The second battery, A first voltage supply unit is configured to supply a first operating voltage for operating the first control unit based on a first power supply voltage supplied from the first battery, A communication control unit for controlling the aforementioned communication device, The system includes a second voltage supply unit that is capable of supplying a second operating voltage for operating the communication control unit based on the first power supply voltage supplied from the first battery, and is configured to supply the second operating voltage for operating the communication control unit based on the second power supply voltage supplied from the second battery, When the first power supply voltage is not supplied from the first battery, The communication control unit is configured to control the communication device to receive the update program using the second operating voltage supplied based on the second power supply voltage supplied from the second battery, and The first control unit is configured to store the update program in the second storage unit using a first operating voltage supplied based on the second power supply voltage supplied from the second battery.

2. The power tool according to claim 1, wherein the first control unit is configured to drive the electric motor by executing the control program with the processor while storing the update program received by the communication device in the second storage unit.

3. The aforementioned electric motor is an electric motor that drives the binding section that uses wire to tie together reinforcing bars, The control program is a control program for driving the electric motor to drive the binding unit. The electric tool according to claim 1, wherein the electric tool is a rebar tying machine configured to tie rebars using the wire.

4. A motor control unit that controls the current supplied to the electric motor based on a control signal generated by the first control unit, wherein when the communication device receives the update program, the state changes from one in which the first power supply voltage was not supplied from the first battery to one in which the first power supply voltage is supplied from the first battery, The communication control unit is configured to control the communication device with a second operating voltage supplied based on the first power supply voltage supplied from the first battery, and The power tool according to claim 1, characterized in that the motor control unit is configured to drive the electric motor based on the control program using the first operating voltage supplied based on the first power supply voltage supplied from the first battery.

5. A first voltage line is configured to connect the first voltage supply unit and the second voltage supply unit and to supply the first power supply voltage, The system further includes a second voltage line that connects the first voltage supply unit and the second voltage supply unit and is configured to supply a second voltage lower than the first power supply voltage, When the first power supply voltage is not supplied from the first battery to the first voltage line, The second voltage supply unit is configured to supply the second operating voltage to the communication control unit based on the second power supply voltage supplied from the second battery, and to supply the second voltage to the second voltage line. The first voltage supply unit is configured to supply the first operating voltage to the motor control unit based on the second voltage supplied to the second voltage line. The power tool according to claim 4.

6. The motor control unit and the first voltage supply unit are mounted on the first wiring board, The second wiring board on which the communication control unit and the second voltage supply unit are mounted, The first connector provided on the first wiring board, The second connector provided on the second wiring board, The power tool according to claim 5, comprising a cable connecting the first connector and the second connector, and including a power line constituting at least a portion of the first voltage line and a power line constituting at least a portion of the second voltage line.

7. The power tool according to claim 1, configured to be attachable to equipment.

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