Charging systems, battery packs and chargers

Abstract

The present invention provides a charging system, a battery pack, and a charger. A highly reliable charger (40) includes a functional circuit (58) and a self-diagnostic circuit (60). The functional circuit (58) allows charging power to be output to the battery pack based on the input of normal information from the battery pack, and forcibly inhibits charging power from being output to the battery pack based on the input of abnormal information from the battery pack. The battery pack sends normal information or abnormal information to the charger based on the state of the battery pack, but if an abnormal setting request is received from the charger (40), the abnormal information is sent regardless of the state of the battery pack. The self-diagnostic circuit (60) sends an abnormal setting request to the battery pack to cause the battery pack to send abnormal information, and diagnoses whether the functional circuit (58) is operating properly.

Description

Technical Field

[0001] The present invention relates to a technique for charging a battery. Background Art

[0002] A charger for charging a battery is disclosed in the following Patent Document 1. The charger disclosed in Patent Document 1 is configured to perform a self-diagnosis for confirming whether the charger is operating normally before starting to charge the battery.

[0003] Patent Document 1: Japanese Patent No. 5576264

[0004] If a battery pack is charged using a charger that has an abnormality, the battery pack may not be properly charged and the charger and the battery pack may fail. Therefore, a higher reliability is desired in chargers. Summary of the invention

[0005] An object of one embodiment of the present invention is to provide a charger with higher reliability.

[0006] A charging system according to one embodiment of the present invention includes a battery pack and a charger. The battery pack is detachable from an electric working machine and is configured to supply electric power to the electric working machine. The charger is detachable from the battery pack and is configured to supply charging power to the battery pack.

[0007] The battery pack includes a battery and an information output circuit. The battery is configured to be charged by charging power. The information output circuit outputs abnormal information to the charger when the battery pack is in a specific abnormal state, and outputs normal information to the charger when the battery pack is not in the specific abnormal state. The information output circuit also outputs abnormal information to the charger regardless of whether the battery pack is in the specific abnormal state in response to receiving an abnormal setting request from the charger.

[0008] The charger includes a charging power generation circuit, a functional circuit, and a self-diagnosis circuit. The charging power generation circuit generates charging power. The functional circuit allows the charging power generated by the charging power generation circuit to be output to the battery pack in response to normal information being input from the battery pack, and forcibly suppresses the charging power from being output to the battery pack even if the charging power is generated by the charging power generation circuit in response to abnormal information being input from the battery pack. The self-diagnosis circuit performs a self-diagnosis process.

[0009] The self-diagnosis process includes an abnormal setting request process, an operation information acquisition process, and a functional circuit diagnosis process. In the abnormal setting request process, an abnormal setting request is sent to the battery pack at a specific timing when normal information is input to the charger. In the operation information acquisition process, when abnormal information is input to the charger through the abnormal setting request process, operation information reflecting the operation state of the functional circuit is acquired. The functional circuit diagnosis process diagnoses whether the functional circuit is operating properly based on the operation information acquired through the operation information acquisition process.

[0010] In the charging system thus constructed, the self-diagnosis process of the charger is performed in cooperation with the battery pack. That is, in the self-diagnosis process, the battery pack is intentionally caused to output abnormal information, and the function circuit of the charger is judged based on the abnormal information whether it is operating properly. Therefore, a more reliable charger can be provided.

[0011] Furthermore, “the functional circuit operates appropriately” may mean, for example, that even if the charging power is generated by the charging power generation circuit, the functional circuit operates so as to forcibly suppress the charging power from being output to the battery pack.

[0012] In addition, the functional circuit may be configured to realize the function by hardware processing instead of software processing. For example, the functional circuit may have the function of receiving a specific control signal and outputting the charging power to the battery pack or stopping the output of the charging power based on the control signal, and may have the function of forcibly suppressing the output of the charging power to the battery pack regardless of the control signal in response to the input of abnormal information from the battery pack.

[0013] The self-diagnostic circuit may be configured to execute a self-diagnostic process including a specific function diagnostic process for diagnosing whether a specific function is properly implemented in the charger when normal information is input to the charger.

[0014] In the charging system configured in this way, when normal information is input from the battery pack to the charger and when abnormal information is input, it is possible to diagnose whether the charger is operating properly. Therefore, the reliability of the charger can be further improved.

[0015] The self-diagnosis circuit of the charger may also be configured to execute a self-diagnosis process including an abnormality release request process. In the abnormality release request process, an abnormality release request is sent to the battery pack after the execution of the action information acquisition process. The information output circuit of the battery pack may also be configured to output normal information or abnormal information corresponding to whether the battery pack is in a specific abnormal state to the charger in response to the abnormality release request received from the charger.

[0016] In the charging system configured in this manner, after the charger intentionally outputs abnormality information in response to the abnormality setting request, the charger can easily cancel the output of the intentional abnormality information in response to the abnormality cancellation request.

[0017] The functional circuit may also include a power path, a switch circuit, and a forced cutoff circuit. The power path is configured to supply charging power generated by the charging power generation circuit to the battery pack installed in the charger. The switch circuit is configured to conduct the power path in response to the input of a switch drive signal, and to cut off the power path in response to the input of no switch drive signal. The forced cutoff circuit is configured to cause the switch circuit to operate in response to the switch drive signal when normal information is input to the charger, and to cause the switch circuit to forcibly cut off the power path regardless of whether the switch drive signal is input to the switch circuit when abnormal information is input to the charger.

[0018] In the charging system configured in this way, it is possible to appropriately diagnose whether the switch circuit forcibly interrupts the power path based on the abnormality information from the battery pack.

[0019] The charger may further include a separate functional circuit configured to realize different functions when normal information is input from the battery pack and when abnormal information is input from the battery pack.

[0020] The self-diagnostic circuit may also perform a self-diagnostic process including a separate diagnostic process. In the separate diagnostic process, the separate functional circuit is diagnosed to be operating properly by comparing the operating state of the separate functional circuit when normal information is input to the charger with the operating state of the separate functional circuit when abnormal information is input to the charger through the abnormal setting request process.

[0021] In the charging system configured in this way, both the functional circuit and the separate functional circuit can be diagnosed appropriately and efficiently, and the reliability of the charger including the two functional circuits can be improved.

[0022] The separate functional circuit may also include a pre-charging circuit and a forced stop circuit. The pre-charging circuit is configured to be connected in parallel with the switch circuit, and outputs charging power to the battery pack in a limited manner according to the input of a charging signal. The forced stop circuit is configured to operate the pre-charging circuit according to the pre-charging signal when normal information is input to the charger, and to stop the operation of the pre-charging circuit regardless of whether the pre-charging signal is input when abnormal information is input to the charger.

[0023] In the charging system configured in this manner, it is possible to appropriately diagnose whether or not the pre-charging circuit has stopped operating based on abnormality information from the battery pack.

[0024] A battery pack according to another embodiment of the present invention is configured to be attachable to and detachable from an electric working machine and a charger. The battery pack includes a battery and an information output circuit. The battery is charged by charging power supplied from the charger. The information output circuit outputs abnormal information to the charger when the battery pack is in a specific abnormal state, outputs normal information to the charger when the battery pack is not in a specific abnormal state, and outputs abnormal information to the charger regardless of whether the battery pack is in a specific abnormal state in response to receiving an abnormal setting request from the charger.

[0025] In the battery pack thus configured, when an abnormality setting request is received from the charger, abnormality information is output even when the battery pack is not in a specific abnormal state. Thus, the charger can confirm the operation when abnormality information is output from the battery pack, which can contribute to improving the reliability of the charger.

[0026] A charger according to another aspect of the present invention is configured to be detachable from a battery pack, the battery pack is detachable from an electric working machine, and the charger is configured to supply charging power to the battery pack. The charger includes a charging power generation circuit, a functional circuit, and a self-diagnosis circuit.

[0027] The charging power generation circuit generates charging power. The functional circuit allows the charging power generated by the charging power generation circuit to be output to the battery pack in response to the input of normal information from the battery pack, and forcibly suppresses the charging power from being output to the battery pack even if the charging power is generated by the charging power generation circuit in response to the input of abnormal information from the battery pack. In addition, the battery pack is configured to output abnormal information to the charger when the battery pack is in a specific abnormal state, to output normal information to the charger when the battery pack is not in a specific abnormal state, and to output abnormal information to the charger regardless of whether the battery pack is in a specific abnormal state in response to the receipt of an abnormal setting request from the charger. The self-diagnosis circuit performs self-diagnosis processing.

[0028] The self-diagnosis process includes an abnormal setting request process, an operation information acquisition process, and a functional circuit diagnosis process. In the abnormal setting request process, an abnormal setting request is sent to the battery pack at a specific timing when normal information is input to the charger. In the operation information acquisition process, when abnormal information is input to the charger through the abnormal setting request process, operation information reflecting the operation state of the functional circuit is acquired. The functional circuit diagnosis process diagnoses whether the functional circuit is operating properly based on the operation information acquired through the operation information acquisition process.

[0029] In the charger configured in this way, the self-diagnosis process is performed in cooperation with the battery pack, so a charger with higher reliability can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is an explanatory diagram showing the electrical structure of the battery pack according to the embodiment.

[0031] Figure 2 It is an explanatory diagram showing the electrical structure of the charger according to the embodiment.

[0032] Figure 3 It is an explanatory diagram showing the electrical structure of the working machine body according to the embodiment.

[0033] Figure 4 This is a circuit diagram showing a specific structure of a switch activation circuit of a charger.

[0034] Figure 5 : is a circuit diagram showing the specific configuration of a line switch circuit and a pre-charge circuit of a charger.

[0035] Figure 6 : is a timing chart showing an example of executing the self-diagnosis of the charger.

[0036] Figure 7 This is a flowchart of a portion of the charger main process executed by the charger.

[0037] Figure 8 is another part of the charger main processing performed by the charger ( Figure 7 Continuation of the flowchart.

[0038] Fig. 9 This is a flowchart of the battery main process executed by the battery pack.

[0039] Description of Reference Numerals

[0040] 10...battery pack; 11...positive terminal; 12...negative terminal; 20...battery; 23...battery control circuit; 40...charger; 41...positive terminal; 42...negative terminal; 50...power plug; 51...rectifier circuit; 52...circuit; 53...smoothing circuit; 54...main converter; 54c...switch control circuit; 55...positive line; 56...negative line; 58...line switch circuit; 58b, 59b...forced cut-off circuit; 59...pre-charge circuit; 60...charge control circuit; 64...output setting circuit; 67...switch start circuit; 200...operating machine body. DETAILED DESCRIPTION

[0041] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.

[0042] [Implementation Method]

[0043] (1) Overview of charging system and electric working machine

[0044] Reference Figure 1 to Figure 3 A charging system and an electric working machine according to the present embodiment will be described.

[0045] The charging system of this embodiment includes Figure 1 The battery pack 10 and Figure 2 The charger 40 is shown. The charger 40 is configured to be able to attach and detach the battery pack 10 .

[0046] like Figure 1 As shown, the battery pack 10 includes a battery 20. The battery 20 is a secondary battery that can be charged and discharged. The battery 20 may be any secondary battery. In the present embodiment, the battery 20 is, for example, a lithium ion battery.

[0047] The battery 20 of the present embodiment includes a first cell group 21 and a second cell group 22 connected in series. The first cell group 21 and the second cell group 22 each include a plurality of cells. In each of the first cell group 21 and the second cell group 22, the plurality of cells may be connected in any manner. In the present embodiment, in each of the first cell group 21 and the second cell group 22, the plurality of cells are connected in series, for example.

[0048] The rated voltage values ​​of the first unit group 21 and the second unit group 22 may also be arbitrary values. In the present embodiment, the rated voltage values ​​of the first unit group 21 and the second unit group 22 are both 28.8V, for example, and the rated voltage value of the battery 20 is 57.6V, for example. In addition, the first unit group 21 and the second unit group 22 of the present embodiment each include, for example, 8 units connected in series, and the rated voltage value of each unit is, for example, 3.6V.

[0049] The actual voltage value of the battery 20 may vary depending on the state of charge. Specifically, the voltage value of the battery 20 may be a value lower than 57.6V, or a value higher than 57.6V (e.g., 64V). In addition, the number of cells of the battery 20, the rated voltage value of the cells, and the rated voltage value of the battery 20 are examples. The number of cells of the battery 20, the rated voltage value of the cells, and the rated voltage value of the battery 20 may adopt various values.

[0050] The battery pack 10 can be attached to and detached from a working machine body 200 (see Figure 3 The battery pack 10 is configured to supply the electric power of the battery 20 (hereinafter referred to as "battery power") to the electric device on which the battery pack 10 is mounted.

[0051] The electric working machine of this embodiment includes Figure 1 The battery pack 10 and Figure 3The working machine body 200 is shown. The working machine body 200 is configured so that the battery pack 10 can be attached and detached.

[0052] When the battery pack 10 is mounted on the working machine body 200, battery power is input to the working machine body 200. The working machine body 200 operates by the battery power.

[0053] The working machine body 200 is configured to be able to perform work corresponding to any of various uses, such as gardening, masonry, metalworking, and woodworking. The electric working machine of this embodiment may be, for example, a rechargeable lawn mower for mowing grass or small-diameter wood.

[0054] (2) Battery pack structure

[0055] like Figure 1 As shown, the battery pack 10 includes a positive electrode terminal 11 , a negative electrode terminal 12 , a center terminal 13 , an ES terminal 14 , and a communication terminal 15 .

[0056] The positive terminal 11 is connected to the positive electrode of the battery 20 (specifically, the positive electrode of the first cell group 21). The negative terminal 12 is connected to the negative electrode of the battery 20 (specifically, the negative electrode of the second cell group 22). The center terminal 13 is connected to the positive electrode of the second cell group 22 of the battery 20 (in other words, the negative electrode of the first cell group 21).

[0057] like Figure 1 As shown, the battery pack 10 further includes a battery control circuit 23 , an ES output circuit 24 , a communication circuit 25 , and a power supply circuit 31 .

[0058] The ES output circuit 24 is connected to the ES terminal 14. The communication circuit 25 is connected to the communication terminal 15. In addition, the ES output circuit 24 and the communication circuit 25 are connected to the battery control circuit 23.

[0059] The voltage detection circuit 32 outputs battery voltage information indicating a value (hereinafter referred to as "battery voltage value") of the voltage of the battery 20 (hereinafter referred to as "battery voltage") to the battery control circuit 23. The battery voltage information includes, for example, at least one of information indicating the voltage value of the first cell group 21, information indicating the voltage value of the second cell group 22, and information indicating the voltage value of the battery 20.

[0060] When discharging from the battery 20 to the electric device, the current detection circuit 33 outputs discharge current information indicating the value of the discharge current discharged from the battery 20 to the battery control circuit 23. When charging the battery 20 by the charger 40, the current detection circuit 33 outputs charging current information indicating the value of the charging current supplied from the charger 40 to the battery 20 to the battery control circuit 23.

[0061] The temperature detection circuit 34 detects the temperature of the battery 20 , and outputs temperature information indicating the detected temperature to the battery control circuit 23 .

[0062] The battery voltage is input to the power circuit 31 via the cut-off circuit 30. The cut-off circuit 30 is provided in the current path connecting the positive electrode of the battery 20 and the power circuit 31, and turns on or off the current path. The cut-off circuit 30 is turned on or off by the battery control circuit 23. If the cut-off circuit 30 is turned on, the above-mentioned current path is turned on, and if the cut-off circuit 30 is turned off, the above-mentioned current path is cut off. The cut-off circuit 30 may also be configured in any manner. For example, the cut-off circuit 30 may also include a switch element that turns on or off the above-mentioned current path.

[0063] The power supply circuit 31 converts the input DC voltage into a DC control voltage Vc having a voltage value lower than the input voltage and outputs the DC control voltage Vc. The control voltage Vc generated by the power supply circuit 31 is used as a power source for each part in the battery pack 10 including the battery control circuit 23.

[0064] The power supply circuit 31 may be configured in any manner. The power supply circuit 31 may also be configured to include a switching regulator or a linear regulator, and the switching regulator or the linear regulator converts the input voltage into the control voltage Vc. The voltage value of the control voltage Vc and the voltage value of the first power supply voltage Vcc may both be arbitrary values.

[0065] The battery control circuit 23 includes, for example, a microcomputer including a CPU and a memory. The memory may also include a semiconductor memory such as a RAM, a ROM, or a flash memory. The memory stores various programs and data that the CPU reads and executes in order to realize various functions of the battery pack 10. The programs stored in the memory include a program for the battery main processing described later. The various functions are not limited to software processing, and part or all of them may be realized by hardware combining a logic circuit, an analog circuit, and the like.

[0066] The battery control circuit 23 is configured to detect whether the charger 40 or the working machine body 200 is mounted on the battery pack 10. If the battery control circuit 23 detects that the battery pack 10 is mounted on the charger 40, the battery side charging control process is executed. In the battery side charging control process, the charging of the battery 20 by the charger 40 is controlled based on various information such as battery voltage information, discharge current information, charge current information, and temperature information. If the battery control circuit 23 detects that the battery pack 10 is mounted on the working machine body 200, the discharge from the battery 20 to the working machine body 200 is controlled based on the above-mentioned various information.

[0067] The battery control circuit 23 has a data communication (e.g., serial communication) function. Specifically, the battery control circuit 23 transmits transmission data from the communication terminal 15 via the communication circuit 25. In addition, the battery control circuit 23 receives reception data input to the communication terminal 15 via the communication circuit 25. In addition, a transmission terminal for transmitting transmission data and a reception terminal for receiving reception data may be provided separately.

[0068] In the battery-side charging control process, the battery control circuit 23 transmits and receives information required for charging the battery 20 by performing data communication with the charger 40. Specifically, for example, the battery control circuit 23 calculates the value of the charging current required to charge the battery 20 based on the battery voltage, and transmits a charging current command value indicating the value to the charger 40.

[0069] The battery control circuit 23 determines whether the battery 20 is in an over-discharge state based on the battery voltage information input from the voltage detection circuit 32. The battery control circuit 23 may determine whether the battery 20 is in an over-discharge state by any method. For example, the battery control circuit 23 may determine that the battery 20 is in an over-discharge state when the battery voltage value indicated by the battery voltage information is less than a predetermined voltage lower limit value.

[0070] The battery control circuit 23 turns on the cutoff circuit 30 when the battery 20 is not in an over-discharged state, thereby supplying battery power to the power supply circuit 31 via the cutoff circuit 30. In this case, the power supply circuit 31 converts the battery voltage into a control voltage Vc and outputs it.

[0071] When the battery control circuit 23 determines that the battery 20 is in an over-discharge state, the battery control circuit 23 is set to the shutdown mode. Specifically, the battery control circuit 23 cuts off the input of the battery voltage to the power supply circuit 31 by disconnecting the cutoff circuit 30, thereby stopping the output of the control voltage Vc from the power supply circuit 31. In the shutdown mode, since the control voltage Vc is not input to the battery control circuit 23, the operation of the battery control circuit 23 is stopped.

[0072] The voltage detection circuit 32 may output information indicating the voltage value of each cell in the battery 20 to the battery control circuit 23. In this case, the battery control circuit 23 may determine that the battery is in an overdischarge state when the voltage value of at least one cell is less than a predetermined cell voltage lower limit value.

[0073] In addition, the voltage detection circuit 32 may also determine whether the battery 20 is in an over-discharge state. That is, the voltage detection circuit 32 may also determine that the battery 20 is in an over-discharge state when the battery voltage value is less than a predetermined voltage lower limit value, or when the voltage value of at least one cell is less than a predetermined cell voltage lower limit value. In this case, the battery control circuit 23 may also disconnect the cut-off circuit 30 when the voltage detection circuit 32 determines that the battery 20 is in an over-discharge state.

[0074] Since the battery control circuit 23 in the shutdown mode stops its operation, it cannot turn on the cutoff circuit 30 by itself. The shutdown mode of the battery control circuit 23 is released by attaching the battery pack 10 to the charger 40 in operation. The battery pack 10 of the present embodiment is configured so that when attached to the charger 40 in operation, a first power supply voltage Vcc described later is input from the charger 40. The first power supply voltage Vcc input from the charger 40 is input to the power supply circuit 31.

[0075] If the first power supply voltage Vcc is input to the power supply circuit 31 in the shutdown mode, the power supply circuit 31 converts the first power supply voltage Vcc into the control voltage Vc and outputs it. As a result, the battery control circuit 23 is activated. When the battery voltage value of the battery control circuit 23 activated in the shutdown mode becomes above the voltage lower limit value due to the battery 20 being charged, the cut-off circuit 30 is turned on, thereby releasing the shutdown mode. As a result, the battery voltage is input to the power supply circuit 31, and the power supply circuit 31 can generate the control voltage Vc from the battery voltage.

[0076] The battery control circuit 23 also monitors whether the battery pack 10 is in a specific abnormal state, and outputs a permission command or a prohibition command to the ES output circuit 24 according to the monitoring result. The specific abnormal state may be a state where discharge from the battery 20 or charging of the battery 20 should be stopped, for example.

[0077] The battery control circuit 23 may determine whether the battery pack 10 is in a specific abnormal state by any method. For example, the battery control circuit 23 may determine whether the battery pack 10 is in a specific abnormal state based on at least one of the battery voltage information, discharge current information, charge current information, and temperature information.

[0078] In addition, the specific abnormal state may be any state. For example, when the battery 20 is in an over-discharge state, or when the over-discharge state continues for a certain period of time, it may be determined that the battery pack 10 is in a specific abnormal state. In addition, for example, when the value of the discharge current from the battery 20 exceeds a predetermined current upper limit value, or when the state of exceeding the current upper limit value continues for a certain period of time, it may be determined that the battery pack 10 is in a specific abnormal state. In addition, for example, when the temperature of the battery 20 exceeds a predetermined temperature upper limit value, or when the state of exceeding the temperature upper limit value continues for a certain period of time, it may be determined that the battery pack 10 is in a specific abnormal state.

[0079] When the battery pack 10 is not in a specific abnormal state, the battery control circuit 23 outputs a permission command (in this embodiment, for example, a signal of an H level) to the ES output circuit 24. When the battery pack 10 is in a specific abnormal state, the battery control circuit 23 outputs a prohibition command (in this embodiment, for example, a signal of an L level) to the ES output circuit 24.

[0080] The ES output circuit 24 outputs an ES command. The ES command includes an ES permission command and an ES prohibition command. When the ES output circuit 24 receives a permission command from the battery control circuit 23, it outputs an ES permission command via the ES terminal 14. When the ES output circuit 24 receives a prohibition command from the battery control circuit 23, it outputs an ES prohibition command via the ES terminal 14.

[0081] More specifically, when the ES output circuit 24 of the present embodiment receives a permission instruction from the battery control circuit 23, the input impedance of the ES terminal 14 (i.e., the impedance of the ES output circuit 24 observed from the ES terminal 14) is low impedance. On the other hand, when the ES output circuit 24 of the present embodiment receives a prohibition instruction from the battery control circuit 23, the input impedance of the ES terminal 14 is high impedance. In other words, in the ES output circuit 24 of the present embodiment, outputting an ES permission instruction means that the input impedance of the ES terminal 14 is low impedance, and outputting an ES prohibition instruction means that the input impedance of the ES terminal 14 is high impedance. However, the ES permission instruction and the ES prohibition instruction may adopt any electrical state.

[0082] (3) Charger structure

[0083] like Figure 2 As shown, the charger 40 includes a positive electrode terminal 41 , a negative electrode terminal 42 , a center terminal 43 , an ES terminal 44 , and a communication terminal 45 .

[0084] If the battery pack 10 is installed on the charger 40, the positive terminal 11 of the battery pack 10 is connected to the positive terminal 41, the negative terminal 12 of the battery pack 10 is connected to the negative terminal 42, the center terminal 13 of the battery pack 10 is connected to the center terminal 43, the ES terminal 14 of the battery pack 10 is connected to the ES terminal 44, and the communication terminal 15 of the battery pack 10 is connected to the communication terminal 45.

[0085] The charger 40 also includes a power plug 50, a rectifier circuit 51, a PFC (Power Factor Correction) circuit 52, a smoothing circuit 53, a main converter 54, a positive line 55, a negative line 56, a unit group switching circuit 57, a line switch circuit 58, a pre-charge circuit 59, a charging control circuit 60, a current detection circuit 61, a differential amplifier circuit 62, a low-pass filter 63, an output setting circuit 64 and a switch start circuit 67.

[0086] The power plug 50 is configured to be connected to an AC power source such as a commercial power source that supplies a voltage of 100 V AC, and receives AC power from the AC power source. The rectifier circuit 51 rectifies (e.g., performs full-wave rectification) the AC power input from the power plug 50 and outputs it. The PFC circuit 52 improves the power factor of the AC power input to the rectifier circuit 51. The smoothing circuit 53 smoothes the power output from the PFC circuit 52. The smoothing circuit 53 of this embodiment includes a capacitor for smoothing the power input to the smoothing circuit 53. One of the purposes of providing the PFC circuit 52 is to make the power factor of the AC power close to 1 by making the waveform of the AC current in the AC power input from the power plug 50 close to a sine wave.

[0087] The main converter 54 converts the DC power smoothed by the smoothing circuit 53 into charging power having a voltage suitable for charging the battery 20, and outputs the converted power. In the present embodiment, the main converter 54 is configured as, for example, an isolated step-down switching power supply circuit.

[0088] More specifically, the main converter 54 includes a transformer 54a, a main switch 54b, and a switch control circuit 54c. The DC power smoothed by the smoothing circuit 53 is input to the primary side (ie, the primary winding) of the transformer 54a.

[0089] The main switch 54b is provided on the primary side of the transformer 54a in the supply path of the DC power, and the supply path is turned on or off. The main switch 54b may be any switch. In the present embodiment, the main switch 54b includes a semiconductor switch element (e.g., FET), and the supply path is turned on or off by turning the semiconductor switch element on or off.

[0090] The switch control circuit 54c controls the main switch 54b. When a start signal is input from the switch start circuit 67, the switch control circuit 54c starts, and when a stop signal is input from the switch start circuit 67, the switch control circuit 54c stops operating.

[0091] The switch control circuit 54c turns on or off the main switch 54b based on the switch control signal input from the output setting circuit 64 during startup, thereby causing the secondary side (i.e., the secondary winding) of the transformer 54a to generate charging power for charging the battery 20. The first end of the positive line 55 and the first end of the negative line 56 are connected to the secondary side of the transformer 54a. The charging power generated by the main converter 54 is supplied to the battery pack 10 via the positive line 55 and the negative line 56.

[0092] The second end of the positive line 55 and the second end of the negative line 56 are connected to the unit group switching circuit 57. The unit group switching circuit 57 includes a positive switch 57a and a negative switch 57b that are linked to each other. The positive switch 57a and the negative switch 57b are c-contact type switches. The second end of the positive line 55 is connected to the common terminal of the positive switch 57a, and the second end of the negative line 56 is connected to the common terminal of the negative switch 57b.

[0093] A first terminal of the positive switch 57a is connected to the positive terminal 41, and a second terminal of the positive switch 57a is connected to the center terminal 43. A first terminal of the negative switch 57b is connected to the center terminal 43, and a second terminal of the negative switch 57b is connected to the negative terminal 42.

[0094] The cell group switching circuit 57 switches to the first connection state or the second connection state according to the switching command input from the charging control circuit 60. The first connection state refers to the state in which the positive switch 57a and the negative switch 57b are both connected to the first terminal with a common terminal. The second connection state refers to the state in which the positive switch 57a and the negative switch 57b are both connected to the second terminal with a common terminal.

[0095] In this embodiment, the battery 20 is charged while the cell group switching circuit 57 is alternately switched between the first connection state and the second connection state. That is, the first cell group 21 is charged in the first connection state, and the second cell group 22 is charged in the second connection state.

[0096] The line switch circuit 58 is provided on the positive line 55, and conducts or cuts off the positive line 55. When the line switch circuit 58 receives the first drive signal Sd1 from the charge control circuit 60, the line switch circuit 58 is turned on to conduct the positive line 55, and when the line switch circuit 58 does not receive the first drive signal Sd1 from the charge control circuit 60, the line switch circuit 58 is turned off to cut off the positive line 55.

[0097] In the present embodiment, the first drive signal Sd1 is a pulse signal of a predetermined frequency. When the output terminal of the first drive signal Sd1 of the charging control circuit 60 is at an L level, this corresponds to a state where the first drive signal Sd1 is not output.

[0098] When the line switch circuit 58 is turned on and the positive line 55 is turned on, the battery pack 10 can be supplied with charging power. When the line switch circuit 58 is turned off and the positive line 55 is cut off, the battery pack 10 cannot be supplied with charging power. The line switch circuit 58 may be configured in any manner. In the present embodiment, the line switch circuit 58 is configured as follows, for example Figure 5 As shown. Figure 5 The line switch circuit 58 shown will be described later.

[0099] The charging control circuit 60 includes, for example, a microcomputer including a CPU and a memory. The memory may also include a semiconductor memory such as a RAM, a ROM, or a flash memory. The memory stores various programs or data that the CPU reads and executes in order to realize various functions of the charger 40. The programs stored in the memory include the programs for the charger main processing described later. The various functions are not limited to software processing, but may be partially or entirely implemented using hardware that combines logic circuits and analog circuits.

[0100] The charging control circuit 60 performs normal charging or pre-charging when charging the battery 20 by the charger side charging control process described later. In normal charging, the charging power generated by the main converter 54 is supplied to the battery pack 10 via the line switch circuit 58. On the other hand, in pre-charging, the charging power generated by the main converter 54 is supplied to the battery pack 10 via the pre-charging circuit 59.

[0101] When charging the battery 20, the charging control circuit 60 basically performs normal charging. However, when the battery voltage value before charging starts is lower than the first lower limit value (e.g., 25V), the charging control circuit 60 first performs pre-charging. Specifically, the line switch circuit 58 is turned off, and on the other hand, the second drive signal Sd2 is output to the pre-charging circuit 59 to operate the pre-charging circuit 59, thereby supplying charging power to the battery pack 10 via the pre-charging circuit 59.

[0102] Furthermore, when the battery voltage value is equal to or greater than the second lower limit value by precharging, the process is switched to normal charging. That is, the output of the second drive signal Sd2 is stopped, and the first drive signal Sd1 is output. The second lower limit value may be the same as the first lower limit value, or may be a different value from the first lower limit value.

[0103] The precharge circuit 59 may be configured in any manner. In the present embodiment, the precharge circuit 59 may be configured as follows. Figure 5 As shown. Figure 5 The precharge circuit 59 shown will be described later.

[0104] The current detection circuit 61 is provided on the negative electrode line 56. The current detection circuit 61 outputs a current detection signal Si indicating the value of the charging current (charging current value Ich) output from the main converter 54. The current detection signal Si is an analog signal having a voltage value corresponding to the charging current value Ich. For example, the current detection circuit 61 may be configured to include a shunt resistor (not shown) inserted into the negative electrode line 56, and output a current detection signal Si corresponding to the voltage between the two ends of the shunt resistor. The current detection signal Si is input to the charging control circuit 60 and the differential amplifier circuit 62.

[0105] In the charger side charging control process, the charging control circuit 60 acquires the above-mentioned charging current command value from the battery pack 10 through data communication with the battery pack 10. The charging control circuit 60 generates a PWM signal corresponding to the acquired charging current command value, that is, a pulse signal of a duty ratio corresponding to the charging current command value, and outputs it to the low-pass filter 63. The low-pass filter 63 smoothes the PWM signal input from the charging control circuit 60 and outputs it to the differential amplifier circuit 62.

[0106] The differential amplifier circuit 62 outputs a differential signal Dif corresponding to the difference between the voltage value of the PWM signal smoothed by the low-pass filter 63 (i.e., the value corresponding to the charging current command value) and the voltage value of the current detection signal Si (i.e., the value corresponding to the actual charging current value Ich). The differential signal Dif is input to the output setting circuit 64. In the present embodiment, as the charging current command value, for example, a charging current command value indicating 1000 mA or a value close thereto may be obtained.

[0107] In this embodiment, the charge control circuit 60 outputs a PWM signal corresponding to the charge current command value in both normal charge and pre-charge. Therefore, when the charge current command value indicates 1000 mA, for example, a PWM signal indicating 1000 mA is output in both normal charge and pre-charge. However, the pre-charge circuit 59 includes a limiter circuit 59a as described later (see Figure 5 ), the value of the charging current output from the pre-charging circuit 59 is limited to below a certain level (for example, below 200 mA) through the limiter circuit 59a.

[0108] The output setting circuit 64 includes a CV setting circuit 81, a CV circuit 82, and a first photocoupler 83. The differential signal Dif is input to the secondary side (i.e., the light emitting diode side not shown) of the first photocoupler 83. In the first photocoupler 83, the photodiode emits light of an amount corresponding to the differential signal Dif. The light emitted by the photodiode is received by the primary side (i.e., the phototransistor not shown) of the first photocoupler 83. The first photocoupler 83 outputs a switch control signal corresponding to the amount of light received on the primary side to the switch control circuit 54c.

[0109] Thus, the switch control circuit 54c generates charging power by driving the main switch 54b according to the differential signal Dif. That is, the switch control circuit 54c generates charging power so that the differential signal Dif becomes zero.

[0110] The CV setting value Dcv is input from the charging control circuit 60 to the CV setting circuit 81. In order to suppress the voltage value (charging voltage value Vch) of the charging power output from the main converter 54 from becoming excessively large during the charger-side charging control process, the charging control circuit 60 sets an upper limit value of the charging voltage value Vch, and outputs the digital data indicating the upper limit value, that is, the above-mentioned CV setting value Dcv, to the CV setting circuit 81.

[0111] The CV setting circuit 81 performs predetermined signal processing such as converting the input CV setting value Dcv into an analog CV setting signal. The CV setting signal output from the CV setting circuit 81 is input to the CV circuit 82 .

[0112] The CV setting signal from the CV setting circuit 81 and the analog charging voltage signal indicating the actual charging voltage value Vch are input to the CV circuit 82. The CV circuit 82 compares the CV setting signal and the charging voltage signal, and when the charging voltage signal is larger than the CV setting signal (in other words, when the actual charging voltage value Vch exceeds the upper limit value of the charging voltage value Vch), the output limit signal corresponding to the difference between the two is output to the first photocoupler 83. In addition, the charging voltage signal is also input to the charging control circuit 60. The charging control circuit 60 can obtain the charging voltage value Vch based on the input charging voltage signal.

[0113] When receiving the output limit signal from the CV circuit 82, the first photocoupler 83 outputs a switch control signal for suppressing the charging voltage value Vch to the switch control circuit 54c regardless of the differential signal Dif. Thus, the charging voltage value Vch is suppressed from exceeding the upper limit value.

[0114] In addition, the charging control circuit 60 sets the upper limit value of the charging voltage value Vch to, for example, 38 V during normal charging, and outputs the CV setting value Dcv indicating 38 V. On the other hand, the charging control circuit 60 sets the upper limit value of the charging voltage value Vch to a value lower than that during normal charging (for example, 25 V) during pre-charging, and outputs the CV setting value Dcv indicating the set upper limit value.

[0115] The first photocoupler 83 is configured to receive the FB enable signal Sfb from the charge control circuit 60. The charge control circuit 60 does not output the FB enable signal Sfb when charging of the battery 20 is unnecessary. On the other hand, the charge control circuit 60 outputs the FB enable signal Sfb when charging the battery 20.

[0116] When the FB valid signal Sfb is input, the first photocoupler 83 outputs a switch control signal corresponding to the differential signal Dif to the switch control circuit 54c. On the other hand, when the FB valid signal Sfb is not input, the first photocoupler 83 invalidates the differential signal Dif and outputs a switch control signal for making the charging current value Ich 0A (in other words, for stopping the output of the charging power from the main converter 54).

[0117] The switch start circuit 67 outputs a start signal to the switch control circuit 54c in response to the switch start signal Sac being input from the charge control circuit 60, thereby starting the switch control circuit 54c. The switch start circuit 67 does not output a start signal when the switch start signal Sac is not input from the charge control circuit 60. The switch start signal Sac is a pulse signal of a predetermined frequency (e.g., 500 Hz) in this embodiment. The state in which the output terminal of the switch start signal Sac is at an L level without outputting the pulse signal corresponds to the state in which the switch start signal Sac is not output.

[0118] The switch control circuit 54c operates when a start signal is input from the switch start circuit 67, and controls the main switch 54b according to the switch control signal input from the output setting circuit 64. The switch control circuit 54c stops operating when no start signal is input from the switch start circuit 67. In this case, the main switch 54b is turned off, and charging power is not generated.

[0119] Reference Figure 4 The specific circuit structure of the switch start circuit 67 is described. Figure 4As shown, the switch start circuit 67 includes resistors R31, R32, R33, and R34, capacitors C31 and C32, switch elements T31 and T32, and a second photocoupler 84. In the present embodiment, the switch element T31 is, for example, an NPN bipolar transistor. In the present embodiment, the switch element T32 is, for example, an n-channel MOSFET.

[0120] A switch activation signal Sac, that is, a pulse signal, from the charge control circuit 60 is input to the base of the switch element T31 via a differential circuit including a capacitor C31 and a resistor R31. A first power supply voltage Vcc is applied to the collector of the switch element T31 via a resistor R32.

[0121] The emitter of the switching element T31 is connected to the ground line via the resistor R33, and is connected to the gate of the switching element T32 via the resistor R34. A capacitor C32 is connected in parallel with the resistor R33 between the emitter of the switching element T31 and the ground line. The source of the switching element T32 is connected to the ground line. The drain of the switching element T32 is connected to the secondary side of the second photocoupler (i.e., a light emitting diode not shown).

[0122] With such a configuration, when the switch start signal Sac is not input from the charge control circuit 60, both the switch elements T31 and T32 are turned off. In this case, the second photocoupler 84 outputs a stop signal to the switch control circuit 54c. On the other hand, while the switch start signal Sac is input from the charge control circuit 60, the switch element T31 is periodically turned on and off according to the frequency of the switch start signal Sac.

[0123] The circuit including the resistors R32, R33 and the capacitor C32 functions as an integration circuit. That is, when the switch element T31 is turned on, the capacitor C32 is charged by the first power supply voltage Vcc according to the time constant τ1 of the resistor R32 and the capacitor C32. When the switch element T31 is turned off, the charge charged to the capacitor C32 is discharged through the resistor R33 according to the time constant τ2 of the resistor R33 and the capacitor C32. The time constant τ1 is smaller than the time constant τ2. In addition, the input impedance of the gate of the switch element T32 is very large, so the current input to the gate is 0 or almost 0.

[0124] While the switch activation signal Sac is input to the switch activation circuit 67, the capacitor C32 is charged as described above, thereby maintaining the gate voltage of the switch element T32 at a value that can turn on the switch element T32, thereby turning on the switch element T32. In this case, the second photocoupler 84 outputs the activation signal to the switch control circuit 54c.

[0125] On the other hand, during the period when the switch start signal Sac is not input to the switch start circuit 67, the switch element T31 remains off. Therefore, the charge of the capacitor C32 is discharged via the resistor R33, and the switch element T32 also remains off. In this case, the second photocoupler 84 outputs a stop signal to the switch control circuit 54c. In addition, the start signal and the stop signal are output from the output circuit of the primary side including the phototransistor (not shown) in the second photocoupler 84.

[0126] In the present embodiment, the switch activation signal Sac is not a DC voltage but a pulse signal, and is input to the base of the switching element T31 via the above-mentioned differential circuit.

[0127] Therefore, even if an abnormality occurs in which the voltage of the terminal to which the switch start signal Sac is input in the switch start circuit 67 is fixed at a constant value that can turn on the switch element T31 even though the switch start signal Sac is not output, the switch element T31 is maintained to be turned off by the interposition of the differential circuit. If the switch element T31 is maintained to be turned off, the switch element T32 is also maintained to be turned off as described above. In other words, in the switch start circuit 67 of the present embodiment, the switch elements T31 and T32 are prevented from continuing to be turned on when the above abnormality occurs.

[0128] A rectifier circuit 65 and a smoothing circuit 66 are provided between the main converter 54 and the line switch circuit 58 in the positive line 55. Since the main converter 54 of the present embodiment is an insulation type, the charging power output from the main converter 54 is AC. The rectifier circuit 65 rectifies the AC charging power output from the main converter 54. The smoothing circuit 66 smoothes the charging power rectified by the rectifier circuit 65.

[0129] A diode D01 is provided between the line switch circuit 58 and the cell group switching circuit 57 in the positive line 55. The diode D01 suppresses a reverse flow of current from the positive terminal 41 or the center terminal 43 to the line switch circuit 58 and the precharge circuit 59.

[0130] Charger 40 further includes subconverter 68. Subconverter 68 converts the DC power smoothed by smoothing circuit 53 into power supply power having a voltage value different from the output voltage value of main converter 54 and outputs the power supply power. In the present embodiment, subconverter 68 includes, for example, an isolated step-down switching power supply circuit.

[0131] The power supply power output from the subconverter 68 is input to the power supply circuit 69. The power supply circuit 69 generates a first power supply voltage Vcc and a second power supply voltage VD from the input power supply power. The voltage value of the first power supply voltage Vcc (e.g., 5V) is lower than the voltage value of the second power supply voltage VD (e.g., 12V). The first power supply voltage Vcc is used as a power supply for various parts of the charger 40 including the charging control circuit 60. The second power supply voltage VD is used as a power supply for, for example, a fan and a buzzer, which are not shown.

[0132] The charger 40 further includes an ES input circuit 74 and a communication circuit 75. The ES input circuit 74 is connected to the ES terminal 44. The communication circuit 75 is connected to the communication terminal 45.

[0133] The ES input circuit 74 outputs an ES signal corresponding to the ES command input from the battery pack 10 to the ES terminal 44. The ES signal includes an ES permission signal and an ES prohibition signal. When an ES permission command is input to the ES terminal 44, the ES input circuit 74 outputs an ES permission signal. When an ES prohibition command is input to the ES terminal 44, the ES input circuit 74 outputs an ES prohibition signal. The ES permission signal and the ES prohibition signal may also be arbitrary signals. In the present embodiment, the ES permission signal is an L level signal, and the ES prohibition signal is an H level signal.

[0134] The ES signal output from the ES input circuit 74 is input to the charge control circuit 60 , the line switch circuit 58 , and the precharge circuit 59 .

[0135] The communication circuit 75 receives data transmitted from the battery pack 10 via the communication terminal 45, relays the received data, and outputs it to the charge control circuit 60. In addition, the charge control circuit 60 outputs the data transmitted to the battery pack 10 to the communication circuit 75. The communication circuit 75 relays the data for transmission input from the charge control circuit 60, and transmits it to the battery pack 10 via the communication terminal 45.

[0136] Here, refer to Figure 5 The specific circuit structures of the line switch circuit 58 and the precharge circuit 59 are described below. Figure 5 As shown, the line switch circuit 58 includes switch elements T01 and T02, a charge pump circuit 58a, and a forced cutoff circuit 58b.

[0137] The switching elements T01 and T2 are connected in series in the positive line 55. Specifically, the drain of the switching element T01 is connected to the smoothing circuit 66 (see Figure 2 ) is connected to supply charging power. The source of the switching element T01 is connected to the source of the switching element T02. The drain of the switching element T02 is connected via a diode D01 (refer to Figure 2) is connected to the cell group switching circuit 57. The gates of the switching elements T01 and T02 are connected to each other.

[0138] Therefore, the positive line 55 is conducted when the switching elements T01 and T2 are turned on, and is disconnected when either the switching elements T01 and T2 are turned off. In the present embodiment, the switching elements T01 and T02 are, for example, n-channel MOSFETs.

[0139] The charge pump circuit 58a includes resistors R01, R02, R03, R04, R05, and R06, capacitors C01 and C02, diodes D11, D12, D13, and D14, and switch elements T03 and T04. In the present embodiment, the switch element T03 is, for example, a PNP bipolar transistor. In the present embodiment, the switch element T04 is, for example, an NPN bipolar transistor.

[0140] The resistor R01 and the capacitor C01 are connected between the gate and the source of the switching element T01 (ie, between the gate and the source of the switching element T02 ).

[0141] The second power supply voltage VD is applied to the emitter of the switching element T03. The resistor R03 is connected between the base and the emitter of the switching element T03. The collector of the switching element T03 is connected to the anode of the diode D11. The cathode of the diode D11 is connected to the anode of the diode D13. The cathode of the diode D13 is connected to the gates of the switching elements T01 and T02 via the resistor R05.

[0142] The cathode of the diode D11 is also connected to the first end of the capacitor C02. The second end of the capacitor C02 is connected to the anode of the diode D14. The cathode of the diode D14 is connected to the collector of the switching element T04 via the resistor R06. The resistor R02 is connected between the drain of the switching element T02 and the anode of the diode D14.

[0143] The first end of the resistor R04 is also connected to the base of the switching element T03. The second end of the resistor R04 is connected to the anode of the diode D12. The cathode of the diode D12 is connected to the cathode of the diode D14.

[0144] The emitter of the switching element T04 is connected to the ground line, and the first drive signal Sd1 from the charging control circuit 60 is input to the base of the switching element T04.

[0145] The forced cutoff circuit 58b includes resistors R07, R08, and R09, a capacitor C03, a diode D15, and a switch element T05. In the present embodiment, the switch element T05 is, for example, an n-channel MOSFET.

[0146] The anode of the diode D15 is connected to the ES input circuit 74 (refer to Figure 2 ) is connected to an ES signal (ES permission signal or ES prohibition signal) from an ES input circuit 74. The cathode of the diode D15 is connected to the gate of the switching element T05 via a resistor R09. The source of the switching element T05 is connected to the ground line. The resistor R08 and the capacitor C03 are connected between the gate and the source of the switching element T05, respectively. The drain of the switching element T05 is connected to the gates of the switching elements T01 and T02 via a resistor R07.

[0147] If the ES permission signal (i.e., L level signal) is input to the forced cutoff circuit 58b, the switch element T05 is turned off. In this case, the forced cutoff circuit 58b does not affect the operation of the switch elements T01 and T02. In other words, the switch elements T01 and T02 are turned on or off according to whether the first drive signal Sd1 is input.

[0148] On the other hand, if the ES prohibition signal (i.e., H level signal) is input to the forced disconnection circuit 58b, the switch element T05 is turned on. In this case, the potential of the gate of the switch elements T01 and T02 becomes the same potential as the ground line or a potential close to the same potential. Therefore, regardless of whether the first drive signal Sd1 is input, the switch elements T01 and T02 are forcibly turned off. In other words, during the period when the ES prohibition signal is input, the first drive signal Sd1 from the charging control circuit 60 is invalid.

[0149] When the ES permission signal is input to the forced cutoff circuit 58b, the first drive signal Sd1 is input from the charge control circuit 60, and the switch element T04 is turned on or off according to the frequency of the first drive signal Sd1. When the switch element T04 is repeatedly turned on and off by the first drive signal Sd1, the charge pump circuit 58a operates to increase the voltage of the gates of the switch elements T01 and T02, and the switch elements T01 and T02 are turned on (in other words, the line switch circuit 58 is turned on).

[0150] The forced disconnection circuit 58 b is configured to forcibly disconnect the line switch circuit 58 when an ES disable signal is inputted during hardware processing without performing software processing.

[0151] In addition, the diode D12 is provided to suppress a part of the charging current flowing in the positive line 55 from flowing into the supply path of the second power supply voltage VD. That is, in the present embodiment, in normal charging, the value of the charging voltage (charging voltage value Vch) output from the main converter 54 takes a value within a prescribed range including, for example, 30 V. On the other hand, the voltage value of the second power supply voltage VD is 12 V in the present embodiment, which is greatly different from the charging voltage value Vch.

[0152] Therefore, if the diode D12 is not provided, part of the charging current output from the drain of the switching element T02 may flow into the power supply circuit 69 via the resistor R02, the diode D14, the resistor R04, and the resistor R03. Therefore, in this embodiment, the diode D12 is provided to suppress the above-mentioned charging current from flowing into the power supply circuit 69.

[0153] Next, the precharge circuit 59 will be described. Figure 5 As shown, the precharge circuit 59 includes resistors R11, R12, R14, R15, R16, a diode D21, switch elements T11, T12, a limiter circuit 59a, and a forced cutoff circuit 59b. The limiter circuit 59a includes a resistor R13 and a switch element T13. In the present embodiment, the switch elements T11 and T13 are, for example, PNP bipolar transistors. In the present embodiment, the switch element T12 is, for example, an NPN bipolar transistor.

[0154] The emitter of the switching element T11 is connected to the positive line 55 (closer to the upstream side than the line switch circuit 58) via the resistor R13. In other words, the charging power from the main converter 54 is input to the emitter of the switching element T11 via the limiter circuit 59a. In the limiter circuit 59a, the emitter of the switching element T13 is connected to the positive line 55, the base of the switching element T13 is connected to the emitter of the switching element T11, and the collector of the switching element T13 is connected to the base of the switching element T11. The resistor R11 is connected between the emitter and the base of the switching element T11.

[0155] The collector of the switching element T11 is connected to the anode of the diode D21 , and the cathode of the diode D21 is connected to the positive line 55 (on the downstream side of the line switch circuit 58 ) via the resistor R12 .

[0156] The base of the switching element T11 is connected to the collector of the switching element T12 via the resistor R14. The emitter of the switching element T12 is connected to the ground line. The second drive signal Sd2 is input to the base of the switching element T12 via the resistor R16. The resistor R15 is connected between the base and emitter of the switching element T12.

[0157] The forced cutoff circuit 59b is configured similarly to the forced cutoff circuit 58b of the line switch circuit 58. The drain of the switching element T05 in the forced cutoff circuit 59b is connected to the base of the switching element T12 via the resistor R07.

[0158] When the forced cutoff circuit 59b inputs the ES permission signal (ie, L level signal) to turn off the switch element T05, the forced cutoff circuit 59b does not affect the operation of the switch element T12. In other words, the switch element T12 is turned on or off depending on whether the second drive signal Sd2 is input.

[0159] On the other hand, if the ES prohibition signal (i.e., H level signal) is input to the forced cut-off circuit 59b to turn on the switch element T05, the potential of the base of the switch element T12 becomes the same potential as the ground line or a potential close to the same potential. Therefore, regardless of whether the second drive signal Sd2 is input, the switch element T12 is forcibly turned off. In other words, during the period when the ES prohibition signal is input, the second drive signal Sd2 from the charge control circuit 60 is invalid.

[0160] When the ES permission signal is input to the forced cutoff circuit 59b, the second drive signal Sd2 is input from the charge control circuit 60, and the switch element T12 is turned on. When the switch element T12 is turned on, the switch element T11 is turned on. When the switch element T11 is turned on, the charging current output from the main converter 54 is output to the battery pack 10 via the switch element T11.

[0161] The forced shutoff circuit 59 b is configured to forcibly shut off the precharge circuit 59 when an ES disable signal is inputted during hardware processing without performing software processing.

[0162] The limiter circuit 59a limits the value of the charging current output from the pre-charging circuit 59 to a value below the above-mentioned constant level (e.g., below 200 mA). That is, the limiter circuit 59a is configured so that if the value of the input charging current exceeds the above-mentioned constant level, the switch element T13 is turned on. If the switch element T13 is turned on, the switch element T11 is turned off, thereby stopping the output of the charging current from the pre-charging circuit 59.

[0163] In addition, when the ES disable signal is inputted while the charging control circuit 60 is outputting the first drive signal Sd1 or the second drive signal Sd2, the charging control circuit 60 stops the output of the first drive signal Sd1 or the second drive signal Sd2 by software processing. However, a certain time lag occurs from the input of the ES disable signal to the charging control circuit 60 to the time when the charging control circuit 60 stops the first drive signal Sd1 or the second drive signal Sd2 by software processing.

[0164] However, in this embodiment, when an ES inhibit signal is output from the ES input circuit 74, before the charging control circuit 60 stops the first drive signal Sd1 or the second drive signal Sd2 through software processing, the line switch circuit 58 and the pre-charge circuit 59 are forcibly disconnected through hardware processing of the forced cut-off circuits 58b and 59b.

[0165] In the charger 40 configured as described above, when the charging control circuit 60 is activated by the supply of the first power supply voltage Vc, a charger main process (see Figure 7 , Figure 8 The charger main processing includes self-diagnosis processing (including Figure 7 S140~ Figure 8 S300) and the above-mentioned charger side charging control process ( Figure 8 S310).

[0166] In the charger main process, the charging control circuit 60 first performs a self-diagnosis process when it is detected that the battery pack 10 is mounted on the charger 40. The self-diagnosis process is a process for diagnosing whether the charger 40 is operating properly. In the present embodiment, the first to fifth checks described below are performed. In the self-diagnosis process, when a diagnosis result that the charger 40 is operating properly is obtained, that is, when the results of the first to fifth checks are obtained, the charging control circuit 60 performs the charger side charging control process.

[0167] In the charger side charging control process, the charging control circuit 60 controls the supply of charging power to the battery 20 while communicating data with the battery pack 10, thereby charging the battery 20. Specifically, the charging control circuit 60 obtains various information related to the charging of the battery 20 including the above-mentioned charging current command value from the battery pack 10. Then, the output of the charging power to the battery 20 is controlled based on the various information obtained.

[0168] When charging of the battery 20 is required, the charging control circuit 60 starts charging of the battery 20 under the condition that the ES permission signal is input. That is, the charging control circuit 60 activates the switching control circuit 54c of the main converter 54 by outputting the switching activation signal Sac.

[0169] Next, the charge control circuit 60 determines whether to perform normal charge or pre-charge based on the current battery voltage value. When performing normal charge, the line switch circuit 58 is turned on by outputting the first drive signal Sd1 to the line switch circuit 58. When performing pre-charge, the pre-charge circuit 59 is operated by outputting the second drive signal Sd2 to the pre-charge circuit 59.

[0170] The charge control circuit 60 sets the CV setting value Dcv according to normal charge or precharge, and outputs it to the CV setting circuit 81. The charge control circuit 60 outputs a PWM signal corresponding to the charge current command value obtained from the battery pack 10, and outputs an FB enable signal Sfb.

[0171] Thus, charging power is generated in the main converter 54. Then, the generated charging power is output to the battery pack 10, thereby charging the battery 20. The charging power from the main converter 54 is output to the battery pack 10 via the line switch circuit 58 during normal charging, and is output to the battery pack 10 via the pre-charging circuit 59 during pre-charging.

[0172] The charging control circuit 60 charges the battery 20 while switching the cell group switching circuit 57 alternately between the first connection state and the second connection state. That is, the charging of the first cell group 21 and the charging of the second cell group 22 are performed in parallel. The switching between the first connection state and the second connection state may be performed at any time. For example, the switching may be performed every fixed period (e.g., 1 minute).

[0173] When the ES disable signal is input, the charging control circuit 60 does not charge the battery 20. That is, when the ES disable signal is input, the charging control circuit 60 stops the first drive signal Sd1, the second drive signal Sd2, the switch start signal Sac and the FB valid signal, and also stops the PWM signal. As a result, the main converter 54 is stopped and charging power is not generated.

[0174] (4) Structure of the machine body

[0175] like Figure 3 As shown, the working machine body 200 includes a positive electrode terminal 201 , a negative electrode terminal 202 , an ES terminal 204 , and a communication terminal 205 .

[0176] If the battery pack 10 is installed on the working machine body 200 , the positive terminal 11 of the battery pack 10 is connected to the positive terminal 201 , the negative terminal 12 of the battery pack 10 is connected to the negative terminal 202 , the ES terminal 14 of the battery pack 10 is connected to the ES terminal 204 , and the communication terminal 15 of the battery pack 10 is connected to the communication terminal 205 .

[0177] The working machine body 200 also has a motor drive circuit 211, a motor 212, a drive mechanism 213, an output tool 214, a drive switch 215, a switch drive circuit 216, an operating unit 217, an operation detection circuit 218, a drive control circuit 220, an ES input circuit 224, a communication circuit 225 and a power supply circuit 230.

[0178] Battery power is input to the motor drive circuit 211 from the positive terminal 201 and the negative terminal 202. The motor drive circuit 211 supplies power to the motor 212 based on the drive command input from the drive control circuit 220. The motor 212 rotates by the power supplied from the drive control circuit 220. The drive mechanism 213 transmits the rotation of the motor 212 to the output tool 214. The output tool 214 uses the rotational force of the motor 212 as a driving source and is driven via the drive mechanism 213. The output tool 214 is configured to realize the function of the electric working machine by acting on the outside of the working machine body 200. The output tool 214 may be, for example, a rotary knife for mowing grass or small-diameter wood. In addition, for example, the output tool 214 may also be a drill for drilling holes in the workpiece. In addition, for example, the output tool 214 may also be a blade for air supply or suction.

[0179] A drive switch 215 for opening or closing the current path is provided in the current path between the positive electrode terminal 201 and the motor drive circuit 211. The drive switch 215 is controlled by the drive control circuit 220 via the switch drive circuit 216.

[0180] The operation unit 217 is operated by the user of the electric working machine. The operation detection circuit 218 detects the user's operation on the operation unit 217, and outputs an operation detection signal to the drive control circuit 220 when the operation is detected. When the drive control circuit 220 receives the operation detection signal, it turns on the drive switch 215 and drives the motor drive circuit 211, thereby rotating the motor 212.

[0181] The power supply circuit 230 converts the battery voltage Vb into a DC control power supply voltage Vdm having a voltage value lower than the battery voltage Vb and outputs the DC control power supply voltage Vdm. Each part in the working machine body 200 including the drive control circuit 220 operates according to the control power supply voltage Vdm.

[0182] The ES input circuit 224 is connected to the ES terminal 204. The communication circuit 225 is connected to the communication terminal 205.

[0183] In the present embodiment, the ES input circuit 224 has the same configuration as the ES input circuit 74 in the charger 40. That is, the ES input circuit 224 outputs the ES permission signal or the ES prohibition signal. The ES prohibition signal is input to the drive control circuit 220 and the switch drive circuit 216.

[0184] When the ES permission signal is input, the drive control circuit 220 drives the motor 212 according to the operation of the operating unit 217. When the ES prohibition signal is input, the drive control circuit 220 stops the operation of the drive circuit 211 and turns off the drive switch 215 even if the operating unit 217 is operated. When the ES permission signal is input, the switch drive circuit 216 enables the control of the drive switch 215 by the drive control circuit 220, but when the ES prohibition signal is input, the control of the drive switch 215 by the drive control circuit 220 is invalidated and the drive switch 215 is forcibly turned off.

[0185] The communication circuit 225 receives data transmitted from the battery pack 10 via the communication terminal 205, relays the received data, and outputs it to the drive control circuit 220. In addition, the communication circuit 225 relays the transmission data output from the drive control circuit 220 and outputs it to the communication terminal 205, thereby transmitting the data to the battery pack 10.

[0186] (5) Self-diagnosis and processing

[0187] Next, refer to Figure 6 The above self-diagnosis process performed by the charging control circuit 60 in the charger 40 is specifically described. In the self-diagnosis process of the present embodiment, data communication is performed with the battery pack 10, and the state of the battery pack 10 is intentionally changed by the data communication. Moreover, at least one check is performed before and after the change. More specifically, in the present embodiment, the above-mentioned first to fifth checks are performed in sequence. In addition, the self-diagnosis process is started in a state where an ES permission command is input from the battery pack 10, that is, in a state where an ES permission signal is output from the ES input circuit 74.

[0188] like Figure 6 As shown, after the battery pack 10 is mounted on the charger 40 and before starting the self-diagnosis process, the charging control circuit 60 performs data communication with the battery pack 10 (initial communication process during charging described later), thereby allowing the battery pack 10 to recognize that the battery pack 10 is mounted on the charger 40.

[0189] Before the battery pack 10 is mounted on the charger 40, the ES prohibition command is output from the ES terminal 14. However, if the battery pack 10 is recognized to be mounted on the charger 40 through data communication with the charger 40, the ES prohibition command is output from the ES terminal 14. Figure 6 As shown, an ES permission command is output from the ES terminal 14.

[0190] like Figure 6As shown, when the ES prohibition command is output from the battery pack 10, the ES signal input to the charge control circuit 60 is the ES prohibition signal, but when the ES permission command is output from the battery pack 10, the ES signal input to the charge control circuit 60 is switched to the ES permission signal. When the ES permission signal is input after the initial communication process during charging, the charge control circuit 60 starts the self-diagnosis process. Specifically, first, the first check is performed.

[0191] The main purpose of the first inspection is to confirm that the switch control circuit 54c in the main converter 54 is operating properly.

[0192] The first check is performed in the initial state of the charger 40, that is, Figure 6 As shown, the switch start signal Sac, the FB effective signal Sfb, the first drive signal Sd1 and the second drive signal Sd2 are all turned off, and the set value of the PWM signal is set to 0 mA. In addition, in this embodiment, with respect to a signal, "on" means outputting the signal, and with respect to a signal, "off" means not outputting the signal.

[0193] During the first inspection, if the switch control circuit 54c has no abnormality, the switch control circuit 54c does not operate and the main switch 54b remains off. Therefore, the charging current value Ich and the charging voltage value Vch are both zero or close to zero.

[0194] On the other hand, if an abnormality occurs in the switch control circuit 54c and the switch control circuit 54c is out of control, the charging power may be output from the main converter 54. In this case, the charging voltage value Vth may increase to a value equivalent to that during normal charging (e.g., about 37V) or above, and the charging current value Ith may also increase.

[0195] Therefore, in the first inspection, the voltage value of the charging power output from the main converter 54 (charging voltage value Vch) and the value of the charging current (charging current value Ich) flowing through the positive line 55 are obtained, and the inspection is performed based on them. The charging control circuit 60 obtains the charging current value Ich based on the current detection signal Si input to the charging control circuit 60, and obtains the charging voltage value Vch based on the charging voltage signal input to the charging control circuit 60.

[0196] When the charging voltage value Vch is smaller than the first voltage threshold value Vth1 and the charging current value Ich is smaller than the first current threshold value Ith1, the charging control circuit 60 determines that the switch control circuit 54c is operating properly and determines the result of the first check to be normal. When the charging voltage value Vch is greater than the first voltage threshold value Vth1 or the charging current value Ich is greater than the first current threshold value Ith1, the charging control circuit 60 determines that the switch control circuit 54c is not operating properly and determines the result of the first check to be abnormal.

[0197] The first voltage threshold Vth1 and the first current threshold Ith1 may be determined in any manner. In the present embodiment, for example, the first voltage threshold Vth1 is 30V, and the first current threshold Ith1 is 0.5A.

[0198] If the result of the first check is normal, the second check is performed next. The main purpose of the second check is to confirm whether the switch activation signal Sac functions properly, in other words, whether the switch control circuit 54c can be stopped by turning off the switch activation signal Sac to stop the output of charging power.

[0199] To perform the second check, Figure 6 As shown, the charging control circuit 60 keeps the switch start signal Sac, the first drive signal Sd1 and the second drive signal Sd2 off, and on the other hand, turns on the FB valid signal Sfb, and sets the setting value of the PWM signal to a predetermined value (e.g., 1000 mA) that can be set during normal charging. Then, the second check is performed.

[0200] In this case, the switch control signal for generating a charging current of 1000 mA is input to the switch control circuit 54c from the output setting circuit 64, but the switch activation signal Sac is turned off. Therefore, if the switch activation signal Sac functions properly, the switch control circuit 54c is not activated, and the charging current value Ich and the charging voltage value Vch are both zero or close to zero.

[0201] On the other hand, when the switch start signal Sac does not function properly and the switch control circuit 54c operates based on the switch control signal to generate charging power, it is possible that the charging voltage value Vth becomes the same value as that during normal charging (for example, approximately 37V), and the charging current value Ith also becomes a value corresponding to the set value of the PWM signal (for example, approximately 1A).

[0202] Therefore, in the second inspection, the charging control circuit 60 obtains the charging current value Ich and the charging voltage value Vch in the same manner as in the first inspection. And, when the charging voltage value Vch is smaller than the first voltage threshold value Vth1 and the charging current value Ich is smaller than the first current threshold value Ith1, it is determined that the switch activation signal Sac functions properly, and the result of the second inspection is determined to be normal. When the charging voltage value Vch is greater than or equal to the first voltage threshold value Vth1, or the charging current value Ich is greater than or equal to the first current threshold value Ith1, the charging control circuit 60 determines that the switch activation signal Sac functions properly, and the result of the second inspection is determined to be abnormal.

[0203] If the result of the second inspection is normal, the third inspection is performed next. The main purpose of the third inspection is to confirm whether FB enable signal Sfb functions properly, in other words, whether the output of the charging current can be stopped by turning off FB enable signal Sfb.

[0204] To perform the third check, Figure 6 As shown, the charging control circuit 60 turns off the FB valid signal Sfb and then turns on the switch activation signal Sac. Then, the third check is performed.

[0205] In this case, if the FB valid signal Sfb functions normally, a switch control signal for stopping the output of the charging current is output from the output setting circuit 64 to the switch control circuit 54 c regardless of the differential signal Dif.

[0206] On the other hand, when the FB effective signal Sfb does not function normally due to some important factors such as an abnormality in the transmission path of the FB effective signal Sfb from the charging control circuit 60 to the first photocoupler 83 or an abnormality in the first photocoupler 83, the switch control circuit 54c may operate based on the switch control signal corresponding to the differential signal Dif. In this case, the charging voltage value Vth may become the same value as that in normal charging (for example, about 37V), and the charging current value Ith may also become a value corresponding to the setting value of the PWM signal (for example, about 1A).

[0207] Therefore, in the third inspection, the charging control circuit 60 obtains the charging current value Ich and the charging voltage value Vch in the same manner as in the first inspection. And, when the charging voltage value Vch is smaller than the first voltage threshold value Vth1 and the charging current value Ich is smaller than the first current threshold value Ith1, it is determined that the FB valid signal Sfb functions properly, and the result of the third inspection is determined to be normal. When the charging voltage value Vch is greater than the first voltage threshold value Vth1 or the charging current value Ich is greater than the first current threshold value Ith1, the charging control circuit 60 determines that the FB valid signal Sfb does not function properly, and the result of the third inspection is determined to be abnormal.

[0208] If the result of the third check is normal, the fourth check is performed next. The main purpose of the fourth check is to confirm whether the line switch circuit 58 is forcibly disconnected by hardware processing (in other words, by the forced disconnection circuit 58b) even if the first drive signal Sd1 is output when the ES prohibition command is input from the battery pack 10.

[0209] To perform the fourth check, Figure 6 As shown, the charging control circuit 60 intentionally outputs an ES prohibition instruction from the battery pack 10. Specifically, the charging control circuit 60 sends an ES prohibition request to the battery pack 10 during data communication. The battery control circuit 23 of the battery pack 10 is configured to output a prohibition instruction to the ES output circuit 24 if an ES prohibition request is received from the charger 40, even if the battery pack 10 is not in a specific abnormal state. Therefore, if an ES prohibition request is sent to the battery pack 10, an ES prohibition instruction is output from the ES terminal 14 of the battery pack 10. As a result, an ES prohibition signal is output from the ES input circuit 74 of the charger 40. In addition, in order to perform the fourth check, the first drive signal Sd1 and the FB valid signal Sfb are turned on in sequence.

[0210] In this case, if the ES inhibition signal functions normally, the line switch circuit 58 is forcibly turned off. Therefore, although the charging power is generated by the main converter 54, the charging current is not output from the line switch circuit 58. In other words, although the charging voltage value Vch becomes the same value as that in normal charging (for example, about 37V), the charging current value Ith is zero or a value close to zero.

[0211] On the other hand, if the ES inhibit signal does not function normally due to, for example, an abnormality in the forced cutoff circuit 58b, the line switch circuit 58 may not be disconnected due to hardware processing based on the ES inhibit signal. In this case, the charging current value Ith may become a value corresponding to the set value of the PWM signal (for example, about 1A).

[0212] Therefore, in the fourth inspection, the charging control circuit 60 obtains the charging current value Ich and the charging voltage value Vch. And, when the charging voltage value Vch is greater than or equal to the second voltage threshold value Vth2 and the charging current value Ich is less than the first current threshold value Ith1, it is determined that the line switch circuit 58 is normally disconnected by the ES prohibition instruction, and the result of the fourth inspection is determined to be normal. When the charging voltage value Vch is lower than the second voltage threshold value Vth2 or the charging current value Ich is greater than or equal to the first current threshold value Ith1, the charging control circuit 60 determines that the line switch circuit 58 is not normally disconnected by the ES prohibition instruction, and the result of the fourth inspection is determined to be abnormal.

[0213] If the result of the fourth check is normal, the fifth check is performed next. The main purpose of the fifth check is to confirm whether the precharge circuit 59 is forcibly disconnected by hardware processing (in other words, by the forced disconnection circuit 59b) even if the second drive signal Sd2 is output when the ES prohibition command is input from the battery pack 10.

[0214] To perform the fifth check, Figure 6 As shown, the charging control circuit 60 turns off the first drive signal Sd1 and turns on the second drive signal Sd2 before the fifth check is performed. In addition, the charging current value Ich is obtained and stored as the charging current holding value Ich0. At this time, if the ES inhibition signal functions normally, the charging current holding value Ich0 is zero or a value close to zero.

[0215] After the charge current holding value Ich0 is stored, Figure 6 As shown, the charging control circuit 60 transmits an ES permission request to the battery pack 10 during data communication. When the battery control circuit 23 receives the ES permission request from the charger 40 while outputting the prohibition command, it determines whether a specific abnormal state has occurred in the battery pack 10. And, if the specific abnormal state has not occurred, the permission command is output to the ES output circuit 24. As a result, in the charger 40 that outputs the ES permission command from the ES terminal 14 of the battery pack 10 and receives the ES permission command, an ES permission signal is output from the ES input circuit 74.

[0216] If the charging control circuit 60 confirms that the ES permission signal is output, it performs the fifth check. That is, the current charging current value Ich is obtained. In addition, it is determined whether the difference between the obtained charging current value Ich and the charging current holding value Ich0 (hereinafter referred to as "current deviation") is greater than the second current threshold value Ith2. When the current deviation is greater than the second current threshold value Ith2, it is determined that the pre-charging circuit 59 is normally disconnected in the hardware processing by the ES prohibition instruction, and the result of the fifth check is determined to be normal. When the current deviation is less than the second current threshold value Ith2, the charging control circuit 60 determines that the pre-charging circuit 59 is not normally disconnected in the hardware processing by the ES prohibition instruction, and the result of the fifth check is determined to be abnormal.

[0217] If the result of the fifth inspection is normal, the charging control circuit 60 ends the self-diagnosis process. Figure 6 As shown, by turning off the switch start signal Sac, the FB valid signal Sfb, the first drive signal Sd1 and the second drive signal Sd2, and setting the set value of the PWM signal to 0 mA, the charger 40 returns to the initial state. Then, by starting the above-mentioned charger charge control process, the battery 20 starts to be charged.

[0218] (6) Charger main processing

[0219] For the charger main process including the self-diagnosis process performed by the charging control circuit 60, refer to Figure 7 and Figure 8 When the charging control circuit 60 is activated, the charger main process starts.

[0220] When the charging control circuit 60 starts the charger main process, it performs the initial process in S110. Specifically, the switch start signal Sac, the FB valid signal Sfb, the first drive signal Sd1 and the second drive signal Sd2 are all turned off, and the set value of the PWM signal is set to 0 mA (in other words, the duty cycle of the PWM signal is set to, for example, 0).

[0221] In S120, it is determined whether the battery pack 10 is mounted. The determination in S120 is repeated until the battery pack 10 is mounted. If the battery pack 10 is mounted, the process proceeds to S130.

[0222] In S130, the initial communication process during charging is performed. That is, by performing data communication with the battery control circuit 23 of the battery pack 10, the battery control circuit 23 recognizes that the battery pack 10 is installed in the charger 40. When the battery control circuit 23 is not installed in other devices, the battery control circuit 23 outputs a prohibition command to the ES output circuit 24. If the battery control circuit 23 recognizes that the battery pack 10 is installed in the charger 40, it determines whether the battery pack 10 is in a specific abnormal state. And, when it is not a specific abnormal state, the battery control circuit 23 outputs a permission command to the ES output circuit 24, thereby outputting an ES permission command from the ES terminal 14.

[0223] In S130, after the above-mentioned data communication is performed, the ES permission command is waited for to be output from the battery pack 10. Then, if it is confirmed that the ES permission command is output from the battery pack 10 by inputting the ES permission signal to the charge control circuit 60, the process proceeds to S140.

[0224] In S140, the first check is performed. Specifically, the charging voltage value Vch and the charging current value Ich are obtained. Furthermore, it is determined whether the charging voltage value Vch is smaller than the first voltage threshold value Vth1 (for example, 30V) and whether the charging current value Ich is smaller than the first current threshold value Ith1 (for example, 0.5A). When the charging voltage value Vch is greater than the first voltage threshold value Vth1, or the charging current value Ich is greater than the first current threshold value Ith1, the process moves to S320. In S320, the result of the first check is determined to be abnormal, and the prescribed error processing is performed. After the error processing of S320 is performed, the charger main processing is terminated.

[0225] In S140 , when the charging voltage value Vch is smaller than the first voltage threshold value Vth1 and the charging current value Ich is smaller than the first current threshold value Ith1 , the result of the first inspection is determined to be normal, and the process proceeds to S150 .

[0226] In S150 , from the state where the first check has been performed, the FB enable signal Sfb is changed to be on, and the set value of the PWM signal is changed to the above-mentioned predetermined value (eg, 1000 mA).

[0227] In S160, the second check is performed. Specifically, the charging voltage value Vch and the charging current value Ich are obtained. Furthermore, it is determined whether the charging voltage value Vch is smaller than the first voltage threshold value Vth1 and whether the charging current value Ich is smaller than the first current threshold value Ith1. When the charging voltage value Vch is greater than the first voltage threshold value Vth1, or the charging current value Ich is greater than the first current threshold value Ith1, the process moves to S330. In S330, the result of the second check is determined to be abnormal, and the prescribed error processing is performed. After the error processing of S330 is performed, the charger main processing is terminated.

[0228] In S160 , when the charging voltage value Vch is smaller than the first voltage threshold value Vth1 and the charging current value Ich is smaller than the first current threshold value Ith1 , the result of the second inspection is determined to be normal, and the process proceeds to S170 .

[0229] In S170 , from the state where the second check is performed, the FB enable signal Sfb is first changed to OFF, and then the switch activation signal Sac is changed to ON.

[0230] In S180, the third check is performed. Specifically, the charging voltage value Vch and the charging current value Ich are obtained. Furthermore, it is determined whether the charging voltage value Vch is smaller than the first voltage threshold value Vth1 and whether the charging current value Ich is smaller than the first current threshold value Ith1. When the charging voltage value Vch is greater than the first voltage threshold value Vth1, or the charging current value Ich is greater than the first current threshold value Ith1, the process moves to S340. In S340, the result of the third check is determined to be abnormal, and the prescribed error processing is performed. After the error processing of S340 is performed, the charger main processing ends.

[0231] In S180 , when the charging voltage value Vch is smaller than the first voltage threshold value Vth1 and the charging current value Ich is smaller than the first current threshold value Ith1 , the result of the third inspection is determined to be normal, and the process proceeds to S190 .

[0232] In S190, an ES prohibition request is sent to the battery pack 10 in data communication. In S200, the battery pack 10 waits for a fixed time. The fixed time may be any length. The fixed time may be, for example, a time longer than the time from when the ES prohibition request is sent to when the ES prohibition instruction is output from the battery pack 10 according to the ES prohibition request.

[0233] In S210, it is determined whether it is possible to confirm that the ES prohibition command is output from the battery pack 10. Specifically, if the ES prohibition signal is input to the charging control circuit 60, it is determined that the ES prohibition command is output. If it is not possible to confirm that the ES prohibition command is output, in S350, a predetermined error process is executed to terminate the charger main process. If it is possible to confirm that the ES prohibition command is output, the process moves to S220 (see Figure 8 ).

[0234] In S220, from the state of the third inspection, the first drive signal Sd1 is turned on, and then the FB valid signal is turned on. The timing of turning on the first drive signal Sd1 and the timing of turning on the FB valid signal may be opposite to the above or may be simultaneous.

[0235] In S230, the fourth check is performed. Specifically, the charging voltage value Vch and the charging current value Ich are obtained. Furthermore, it is determined whether the charging voltage value Vch is greater than the second voltage threshold value Vth2 and whether the charging current value Ich is less than the first current threshold value Ith1. When the charging voltage value Vch is less than the second voltage threshold value Vth2, or the charging current value Ich is greater than the first current threshold value Ith1, the process moves to S360. In S360, the result of the fourth check is determined to be abnormal, and the prescribed error processing is performed. After the error processing of S360 is performed, the charger main processing ends.

[0236] In S230 , when the charging voltage value Vch is equal to or higher than the second voltage threshold value Vth2 and the charging current value Ich is smaller than the first current threshold value Ith1 , the result of the fourth inspection is determined to be normal, and the process proceeds to S240 .

[0237] In S240, from the state where the fourth inspection is performed, the first drive signal Sd1 is turned off and the second drive signal is turned on. In S250, the charging current value Ich is acquired and stored as the charging current holding value Ich0.

[0238] In S260, an ES permission request is sent to the battery pack 10 in data communication. In S270, the battery pack 10 waits for a fixed time. The fixed time may be any length. The fixed time may be, for example, a time longer than the time from when the ES permission request is sent to when the ES permission instruction is output from the battery pack 10 according to the ES permission request.

[0239] In S280, it is determined whether it is possible to confirm that the ES permission command is output from the battery pack 10. Specifically, if the ES permission signal is input to the charging control circuit 60, it is determined that the ES permission command is output. If the output of the ES permission command cannot be confirmed, in S370, a predetermined error process is performed and the charger main process is terminated. If the output of the ES permission command can be confirmed, the process moves to S290.

[0240] In S290, the fifth check is performed. Specifically, the current deviation (the difference between the current charging current value Ich and the charging current holding value Ich0) is calculated to determine whether the current deviation is greater than the second current threshold value Ith2 (e.g., 100 mA). If the current deviation is less than the second current threshold value Ith2, the specified error processing is performed in S380, and the charger main processing is terminated. If the current deviation is greater than the second current threshold value Ith2, the result of the fifth check is determined to be normal, and the process moves to S300.

[0241] In S300, the self-diagnosis process is terminated based on the fact that all the inspection results in the self-diagnosis process are normal, and the process for preparing for charging the battery 20 is performed. Specifically, from the state where the fifth inspection is performed, the switch start signal Sac, the FB valid signal Sfb and the second drive signal Sd2 that are currently turned on are turned off. In addition, the set value of the PWM signal is set to 0 mA. In other words, the charging control circuit 60 returns to the initial state (the state when the first inspection is performed) immediately after starting. In addition, in S310, the above-mentioned charger side charging control process is performed, thereby controlling the charging of the battery 20.

[0242] (7)Battery main processing

[0243] Next, refer to Fig. 9 The battery main process executed by the battery control circuit 23 of the battery pack 10 will be described. When the battery control circuit 23 is activated, the battery main process starts. When activated, the battery control circuit 23 outputs a prohibition command to the ES output circuit 24, thereby outputting an ES prohibition command from the ES terminal 14.

[0244] When the battery control circuit 23 starts the battery master process, it is determined in S510 whether the battery pack 10 is connected to an external device (e.g., the charger 40, the working machine body 200, etc.). If the battery pack 10 is not connected to an external device, the determination in S510 is repeated. If the battery pack 10 is connected to an external device, the process proceeds to S520.

[0245] Here, in the present embodiment, it is assumed that the battery pack 10 is mounted on the charger 40 and it is determined in S510 that the battery pack 10 is connected to the external device. In the battery master process, the process executed when the battery pack 10 is mounted on the charger 40 will be described below.

[0246] In S520, the first communication process during charging is performed. That is, data communication is performed with the charging control circuit 60 of the charger 40 to recognize that the battery pack 10 is mounted on the charger 40. In S530, the battery control circuit 23 is shifted to a charging mode for controlling charging of the battery 20 with charging power from the charger 40.

[0247] In S540, it is determined whether the ES permission command can be output. Specifically, it is determined whether the battery pack 10 is in the above-mentioned specific abnormal state. In the case of the specific abnormal state, it is determined that the ES permission command cannot be output, and the process moves to S560. If it is not a specific abnormal state, it is determined that the ES permission command can be output, and the process moves to S550. In S550, the permission command is output to the ES output circuit 24, thereby outputting the ES permission command from the ES terminal 14.

[0248] In S560, an ES prohibition request (see Figure 7 In S570, upon receiving the ES prohibition request from the charger 40, a prohibition instruction is output to the ES output circuit 24, regardless of whether the battery pack 10 is in a specific abnormal state, thereby outputting the ES prohibition instruction from the ES terminal 14.

[0249] In S580, the ES permission request transmitted from charger 40 is received (see Figure 8 In S590, based on the fact that the ES permission request is received from the charger 40, it is determined whether the ES permission instruction can be outputted in the same manner as in S540. If the ES permission instruction cannot be outputted, the process proceeds to S610. If the ES permission instruction can be outputted, the process proceeds to S600.

[0250] In S600, a permission command is output to the ES output circuit 24, thereby outputting an ES permission command from the ES terminal 14. In S610, the above-mentioned battery side charging control process is executed, thereby controlling the charging of the battery 20 by the charging power from the charger 40.

[0251] Here, the features of the charging system of the present embodiment will be supplementally described. In the present embodiment, the charger 40 can also diagnose whether data communication with the battery pack 10 is being performed normally.

[0252] That is, assuming that an abnormality occurs in which the charger 40 and the battery pack 10 cannot communicate normally, even if Figure 7 In S190 of the embodiment, the charger 40 sends an ES prohibition request to the battery pack 10. It is also possible that the ES prohibition instruction is not input from the battery pack 10, even if Figure 8 In S260 , the ES permission request may be sent to the battery pack 10 without inputting the ES permission command from the battery pack 10 .

[0253] In contrast, in this embodiment, Figure 7 If it is not confirmed in S210 that the ES prohibition command is output from the battery pack 10, a predetermined error process is executed in S350. Figure 8 If it is not confirmed in S280 that the ES permission command is output from the battery pack 10, a predetermined error process is executed in S370. Therefore, if an abnormality occurs that the charger 40 and the battery pack 10 cannot normally communicate data, the occurrence of the abnormality can be recognized by the error process.

[0254] In addition, in the charger disclosed in the above-mentioned patent document 1, it is expected that the circuit itself that is the object of diagnosis can be self-diagnosed. However, in the case where the circuit is a circuit connected to a battery pack, even if other circuits (such as wiring, connectors, etc.) used to connect the circuit to the battery pack have a malfunction (such as a broken wire), it is difficult to detect the malfunction.

[0255] On the other hand, in the present embodiment, it is also possible to detect a malfunction of another circuit for connecting the circuit to be diagnosed and the battery pack 10. That is, for example, it is assumed that a malfunction occurs in the wiring system from the ES terminal 44 to the line switch circuit 58 and / or the pre-charge circuit 59 via the ES input circuit 74. In this case, there is a possibility that an appropriate ES signal corresponding to the ES command from the battery pack 10 is not input to the line switch circuit 58 and / or the pre-charge circuit 59. However, even if such a malfunction occurs, it is possible to identify the occurrence of an abnormality by the processing of S210 or S280 described above.

[0256] In addition, during the self-diagnosis process executed in the charger 40, the ES command from the battery pack 10 may change unexpectedly according to the change of the state of the battery pack 10. In contrast, in the present embodiment, an ES prohibition request (S190) is sent to the battery pack 10 before the fourth check (S230) based on the ES command is executed. An ES permission request (S260) is sent to the battery pack 10 before the fifth check (S290) based on the ES command is executed. Therefore, in both the fourth and fifth checks, the inspection can be properly performed in a state where an appropriate ES command corresponding to the inspection purpose is input from the battery pack 10.

[0257] In the battery pack 10, the battery control circuit 23 corresponds to an example of the information output circuit of the present invention, the ES prohibition instruction corresponds to an example of the abnormal information of the present invention, and the ES permission instruction corresponds to an example of the normal information of the present invention. The main converter 54 corresponds to an example of the charging power generation circuit of the present invention. The line switch circuit 58 and the pre-charge circuit 59 correspond to an example of the functional circuit or the separate functional circuit of the present invention. The charging control circuit 60 corresponds to an example of the self-diagnosis circuit of the present invention. The ES prohibition request sent from the charging control circuit 60 to the battery pack 10 corresponds to an example of the abnormal setting request of the present invention. The ES permission request sent from the charging control circuit 60 to the battery pack 10 corresponds to an example of the abnormal release request of the present invention. The positive line 55 corresponds to an example of the power path of the present invention. The line switch circuit 58 corresponds to an example of the switch circuit of the present invention. The pre-charge circuit 59 corresponds to an example of the pre-charge circuit of the present invention. The first drive signal Sd1 corresponds to an example of the switch drive signal of the present invention. The second drive signal Sd2 corresponds to an example of the pre-charge signal of the present invention. The forced cut-off circuit 59b of the pre-charge circuit 59 corresponds to an example of the forced stop circuit of the present invention.

[0258] The processing of S190 is equivalent to an example of the abnormal setting request processing of the present invention. The processing of S230 is equivalent to an example of the action information acquisition processing and the functional circuit diagnosis processing of the present invention. The processing of S140, S160 and S180 are all equivalent to an example of the specific function diagnosis processing of the present invention. The processing of S260 is equivalent to an example of the abnormal release request processing of the present invention. The processing of S290 is equivalent to an example of the split diagnosis processing of the present invention.

[0259] [Other embodiments]

[0260] As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, It can implement with various deformation|transformation.

[0261] (1) In the above-mentioned embodiment, the diagnostic object (hereinafter referred to as "ES corresponding diagnostic object") that determines whether or not the ES prohibition indicator from the battery pack 10 is operating properly is the line switch circuit 58 and the pre-charge circuit 59, but the ES corresponding diagnostic object may be either one of the line switch circuit 58 and the pre-charge circuit 59, or may be another circuit different from these two circuits.

[0262] (2) In the fourth inspection corresponding to the self-diagnosis of the line switch circuit 58, the diagnosis based on the current deviation may be performed in the same manner as in the fifth inspection. Conversely, in the fifth inspection corresponding to the self-diagnosis of the pre-charge circuit 59, the diagnosis based on the charging current value Ich and the charging voltage value Vch may be performed in the same manner as in the fourth inspection, or the diagnosis based on only one of the charging current value Ich and the charging voltage value Vch may be performed.

[0263] (3) In the first inspection, the condition for being normal is that the charging voltage value Vch is smaller than the first voltage threshold value Vth1 and the charging current value Ich is smaller than the first current threshold value Ith1, but only one of these two conditions may be determined. For example, it is also possible not to make a determination based on the charging current value Ich, but to determine that it is normal as long as the charging voltage value Vch is smaller than the first voltage threshold value Vth. This is the same in the second inspection, the third inspection, and the fourth inspection.

[0264] (4) In the above embodiment, five tests (first to fifth tests) are executed in the self-diagnosis process, but the number of tests to be executed may be other than 5. In addition, any test may be performed in each test.

[0265] (5) In the above embodiment, the self-diagnosis process is performed after the battery pack 10 is mounted on the charger 40 and before the battery 20 is charged, but the self-diagnosis process may be performed at any time. In addition, the self-diagnosis process may be performed multiple times while the battery pack 10 is mounted on the charger 40.

[0266] (6) In the above embodiment, as shown in reference Figure 7 and Figure 8 As described above, when an abnormality is determined in any inspection during the self-diagnosis process, the subsequent inspection is not performed and error processing is performed. However, all inspections (the first to fifth inspections in the above embodiment) may be performed regardless of the inspection results.

[0267] (7) It is also possible to implement multiple functions of one component of the above-mentioned embodiment by multiple components, or to implement one function of one component by multiple components. In addition, it is also possible to implement multiple functions of multiple components by one component, or to implement one function implemented by multiple components by one component. In addition, it is also possible to omit a part of the structure of the above-mentioned embodiment. In addition, it is also possible to add or replace at least a part of the structure of the above-mentioned embodiment with respect to the structure of other above-mentioned embodiments.

Claims

1. A charging system comprising: a battery pack configured to be attachable to and detachable from the electric working machine and configured to supply electric power to the electric working machine; and a charger configured to be detachable from the battery pack and configured to supply charging power to the battery pack, The battery pack comprises: a battery configured to be charged by the charging power; and an information output circuit configured to output a prohibition instruction to the charger when the battery pack is in a specific abnormal state, and to output a permission instruction to the charger when the battery pack is not in the specific abnormal state, and output the prohibition instruction to the charger regardless of whether the battery pack is in the specific abnormal state in response to receiving an abnormal setting request from the charger, The charger has: a charging power generation circuit configured to generate the charging power; a functional circuit configured to allow the charging power generated by the charging power generation circuit to be output to the battery pack in response to the input of the permission command from the battery pack, and to forcibly inhibit the charging power from being output to the battery pack even if the charging power is generated by the charging power generation circuit in response to the input of the prohibition command from the battery pack; and A self-diagnosis circuit is configured to perform a self-diagnosis process, The self-diagnosis circuit is configured to execute the self-diagnosis process, wherein the self-diagnosis process includes: abnormal setting request processing, sending the abnormal setting request to the battery pack at a specific timing when the permission command is input to the charger; an operation information acquisition process of acquiring operation information reflecting an operation state of the functional circuit when the prohibition command is input to the charger by the abnormal setting request process; and The functional circuit diagnosis process diagnoses whether the functional circuit is operating properly based on the operation information acquired by the operation information acquisition process.

2. The charging system according to claim 1, in, The self-diagnostic circuit is configured to execute the self-diagnostic process including a specific function diagnostic process for diagnosing whether a specific function is properly implemented in the charger when the permission command is input to the charger.

3. The charging system according to claim 1, in, The self-diagnosis circuit of the charger is configured to execute the self-diagnosis process including an abnormality resolution request process, in which an abnormality resolution request is sent to the battery pack after the operation information acquisition process is executed. The information output circuit of the battery pack is configured to output the permission command or the prohibition command corresponding to whether the battery pack is in the specific abnormal state to the charger in response to receiving the abnormality resolution request from the charger.

4. The charging system according to claim 2, in, The self-diagnosis circuit of the charger is configured to execute the self-diagnosis process including an abnormality resolution request process, in which an abnormality resolution request is sent to the battery pack after the operation information acquisition process is executed. The information output circuit of the battery pack is configured to output the permission command or the prohibition command corresponding to whether the battery pack is in the specific abnormal state to the charger in response to receiving the abnormality resolution request from the charger.

5. The charging system according to any one of claims 1 to 4, in, The functional circuit has: a power path configured to supply the charging power generated by the charging power generation circuit to the battery pack mounted on the charger; a switch circuit configured to conduct the power path in response to input of a switch drive signal and to disconnect the power path in response to no input of the switch drive signal; as well as The forced cut-off circuit is configured to cause the switch circuit to operate according to the switch drive signal when the permission instruction is input to the charger, and to cause the switch circuit to forcibly cut off the power path regardless of whether the switch drive signal is input to the switch circuit when the prohibition instruction is input to the charger.

6. The charging system according to any one of claims 1 to 4, in, The charger further includes a separate functional circuit configured to realize different functions when the permission command is input from the battery pack and when the prohibition command is input from the battery pack. The self-diagnostic circuit is configured to execute the self-diagnostic processing including a split diagnostic processing, in which the action state of the split functional circuit when the permission instruction is input to the charger is compared with the action state of the split functional circuit when the prohibition instruction is input to the charger through the abnormal setting request processing, so as to diagnose whether the split functional circuit is operating properly.

7. The charging system according to claim 5, in, The charger further includes a separate functional circuit configured to realize different functions when the permission command is input from the battery pack and when the prohibition command is input from the battery pack. The self-diagnostic circuit is configured to execute the self-diagnostic processing including a split diagnostic processing, in which the action state of the split functional circuit when the permission instruction is input to the charger is compared with the action state of the split functional circuit when the prohibition instruction is input to the charger through the abnormal setting request processing, so as to diagnose whether the split functional circuit is operating properly.

8. The charging system according to claim 7, in, The functional circuit of the split body has: a pre-charging circuit connected in parallel with the switch circuit and configured to limit the charging power output to the battery pack in response to the input of a pre-charging signal; as well as The forced stop circuit is configured to cause the pre-charge circuit to operate according to the pre-charge signal when the permission command is input to the charger, and to stop the operation of the pre-charge circuit regardless of whether the pre-charge signal is input when the prohibition command is input to the charger.

9. A battery pack configured to be attachable to and detachable from an electric working machine and a charger, in, The battery pack has: a battery configured to be charged by the charging power supplied from the charger; and an information output circuit configured to output a prohibition instruction to the charger when the battery pack is in a specific abnormal state, and to output a permission instruction to the charger when the battery pack is not in the specific abnormal state, and output the prohibition instruction to the charger regardless of whether the battery pack is in the specific abnormal state in response to receiving an abnormal setting request from the charger, The abnormality setting request is transmitted to the battery pack at a specific timing when the permission command is input to the charger.

10. A charger configured to be detachable from a battery pack and configured to supply charging power to the battery pack, wherein the battery pack is detachable from an electric working machine. The charger has: a charging power generation circuit configured to generate the charging power; a functional circuit configured to allow the charging power generated by the charging power generation circuit to be output to the battery pack in response to a permission command being input from the battery pack, and to forcibly inhibit the charging power from being output to the battery pack even if the charging power generation circuit generates the charging power in response to a prohibition command being input from the battery pack, in, the battery pack is configured to output the prohibition instruction to the charger when the battery pack is in a specific abnormal state, output the permission instruction to the charger when the battery pack is not in the specific abnormal state, and output the prohibition instruction to the charger regardless of whether the battery pack is in the specific abnormal state in response to receiving an abnormality setting request from the charger; and A self-diagnosis circuit is configured to perform a self-diagnosis process, The self-diagnosis circuit is configured to execute the self-diagnosis process, wherein the self-diagnosis process includes: abnormal setting request processing, sending the abnormal setting request to the battery pack at a specific timing when the permission command is input to the charger; an operation information acquisition process for acquiring operation information reflecting an operation state of the functional circuit when the prohibition instruction is input to the charger through the abnormal setting request process; as well as The functional circuit diagnosis process diagnoses whether the functional circuit is operating properly based on the operation information acquired by the operation information acquisition process.

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