Battery pack for electric working machine and method for suppressing discharge current in battery pack for electric working machine

Abstract

According to one aspect of the present disclosure, a battery pack for an electric working machine is provided with a battery, a mounting part, a current path, at least one fuse, a temperature detector, and a control circuit. The battery includes a positive electrode and a negative electrode. The attachment part is detachably attached to the electric working machine. The current path is connected with the positive electrode or the negative electrode. The current path causes a discharge current to flow from the battery to the electric working machine. The at least one fuse is located on the current path. The temperature detector outputs a temperature signal representing the temperature of the fuse. The control circuit reduces or stops the discharge current according to the fact that the temperature of the fuse meets the discharge suppression requirement.

Description

Technical Field

[0001] The present disclosure relates to a technology for suppressing discharge current in a battery pack for an electric working machine. Background Art

[0002] Japanese Patent No. 6418874 discloses a battery pack mounted on an electric tool. The battery pack is provided with a fuse. The fuse is provided on a current path where a discharge current flows from the battery to the electric tool. The fuse protects the battery pack from excessive discharge current. Summary of the invention

[0003] If the ambient temperature of the battery pack is high or the power tool is used continuously for a long period of time, the temperature of the fuse may rise, causing the fuse to blow unexpectedly.

[0004] One aspect of the present disclosure preferably provides a battery pack for an electric working machine capable of suppressing accidental blowing of a fuse.

[0005] One aspect of the present disclosure provides a battery pack for an electric working machine including a battery, a mounting portion, a current path, at least one fuse, a temperature detector, and a control circuit.

[0006] The battery has a positive electrode and a negative electrode. The mounting portion is detachably mounted to the electric working machine. The electric working machine is driven by receiving power from the battery. The current path is connected to the positive electrode or the negative electrode. The current path allows a discharge current to flow from the battery to the electric working machine. The at least one fuse is located on the current path. The at least one fuse blows itself, thereby cutting off the current path. The temperature detector outputs a temperature signal indicating a fuse temperature. The fuse temperature corresponds to a temperature of the at least one fuse.

[0007] The control circuit acquires the fuse temperature according to the temperature signal. The control circuit outputs an instruction to reduce or stop the discharge current according to whether the acquired fuse temperature meets the discharge suppression requirement. The discharge suppression requirement is required to reduce or stop the discharge current.

[0008] In the above-mentioned battery pack for electric working machine, the instruction is outputted according to the fact that the fuse temperature has satisfied the discharge suppression requirement. The battery pack for electric working machine or the electric working machine can recognize that the discharge current should be reduced or stopped according to the instruction. Thus, the battery pack for electric working machine or the electric working machine can reduce or stop the discharge current by various methods. Therefore, it is possible to suppress the accidental blowing of the at least one fuse.

[0009] Another aspect of the present disclosure is to provide a method for suppressing discharge current in a battery pack for an electric working machine, comprising:

[0010] detecting a temperature of a fuse, wherein the fuse is located on a current path configured to allow a discharge current to flow from a battery located in a battery pack; and

[0011] When the temperature satisfies a discharge suppression requirement, the discharge current is reduced or stopped, wherein the discharge suppression requirement is required in order to reduce or stop the discharge current.

[0012] The above method can achieve the same effects as the above battery pack for electric working machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a first perspective view of the battery pack according to the embodiment.

[0014] Figure 2 This is a second perspective view of the battery pack according to the embodiment.

[0015] Figure 3 This is a three-dimensional image of the battery pack with the top cover removed.

[0016] Figure 4 It is a three-dimensional diagram of the substrate.

[0017] Figure 5 is a top view of the substrate.

[0018] Figure 6 is a side view of the substrate.

[0019] Figure 7 It is a bottom view of the substrate.

[0020] Figure 8 It is an explanatory diagram showing the electrical structure of a battery pack.

[0021] Fig. 9 It is an explanatory diagram of the electrical structure of the electric working machine according to the embodiment.

[0022] Fig.10 is an explanatory diagram showing an operation example of the battery pack at the time of discharge.

[0023] Fig.11 It is a flow chart of the fuse temperature monitoring process.

[0024] Fig.12 is an explanatory diagram showing an example of a lighting pattern of a display unit. .

[0025] Fig.13 It is a top view of the first modified example of the substrate.

[0026] Fig.14It is a bottom view of the first modification of the substrate.

[0027] Fig.15 It is a top view of the second modification of the substrate.

[0028] Fig.16 It is a top view of the third modified example of the substrate. DETAILED DESCRIPTION

[0029] Exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings.

[0030] [1. Summary of Implementation Methods]

[0031] In the present disclosure, words such as "first" and "second" are only used to distinguish between elements, and are not used to limit the order or number of elements. Therefore, the first element can be called the second element, and similarly, the second element can also be called the first element. In addition, the first element can be present without the second element, and similarly, the second element can be present without the first element.

[0032] One embodiment may provide a battery pack for an electric working machine (hereinafter simply referred to as a “battery pack”), the battery pack having at least one of the following features 1 to 8.

[0033] Feature 1: A battery having a positive electrode and a negative electrode.

[0034] Feature 2: The mounting member is configured to be detachably mounted on the electric working machine (or battery-driven equipment). The electric working machine (or battery-driven equipment) is configured to be driven by receiving electric power from the battery.

[0035] Feature 3: A current path configured to (i) be connected to the positive electrode or the negative electrode and (2) allow a discharge current to flow from the battery to the electric working machine.

[0036] Feature 4: At least one fuse is configured to (i) be located on the current path and (2) melt to cut off the current path.

[0037] Feature 5: The temperature detector is configured to output a temperature signal indicating a fuse temperature. The fuse temperature corresponds to a temperature of the at least one fuse.

[0038] Feature 6: Control circuit (or control unit).

[0039] Feature 7: The control circuit is configured to obtain the fuse temperature based on the temperature signal.

[0040] Feature 8: The control circuit is configured to output an instruction for reducing or stopping the discharge current based on the obtained fuse temperature having satisfied the discharge suppression requirement. The discharge suppression requirement may be a requirement for reducing or stopping the discharge current. The instruction may be an indication or an instruction to reduce or stop the discharge current.

[0041] The temperature detector may be configured to detect the fuse temperature. The temperature signal may represent the detected fuse temperature. The fuse temperature may specifically be the temperature of a heat receiving portion in the battery pack. The heat receiving portion receives the heat generated by the at least one fuse from the at least one fuse. In other words, the heat generated by the at least one fuse is conducted to the heat receiving portion. The heat receiving portion may be in direct or indirect contact with part or all of the at least one fuse. As the temperature of the at least one fuse changes, the temperature of the heat receiving portion also changes. In other words, the temperature of the heat receiving portion directly or indirectly represents the temperature of the at least one fuse. The heat from a part of the at least one fuse may be conducted to the heat receiving portion, or the heat from each fuse of the at least one fuse may be conducted to the heat receiving portion. The temperature detector may be in direct or indirect contact with the heat receiving portion. The temperature detector may also be in direct contact with part or all of the at least one fuse. The temperature detector may be spaced apart from the at least one fuse.

[0042] Each of the at least one fuse may be configured to blow according to the temperature of the fuse satisfying a corresponding blow condition. The blow condition may be satisfied based on the temperature of the fuse exceeding a blow threshold. The blow threshold may be the lowest temperature at which the fuse can blow. The temperature of the fuse may vary according to the magnitude of the current flowing through the fuse. The temperature of the fuse may vary according to the ambient temperature of the fuse.

[0043] The battery pack and / or the electric working machine may reduce or stop the discharge current in various ways according to the instruction. For example, the battery pack may be configured to output a signal directly or indirectly indicating the instruction to the electric working machine according to the instruction having been output. The electric working machine may be configured to suppress or stop the discharge current according to the reception of the signal. The electric working machine may have a motor. In this case, the electric working machine may stop or reduce the power supplied to the motor according to the signal received from the battery pack. The electric working machine may be configured to completely stop consuming the power according to the reception of the signal.

[0044] In addition, for example, the battery pack may be configured to forcibly cut off the discharge current according to the command. More specifically, the battery pack may include, for example, a switch on the current path. The control circuit may close the switch to cut off the current path.

[0045] For example, each of the at least one fuse may be referred to as a fuse element. The “fuse” in the present disclosure includes all electronic devices configured to be melted by Joule heat generated by current flowing through the fuse.

[0046] In the battery pack having at least features 1 to 8, the instruction is outputted based on the fact that the fuse temperature has satisfied the discharge suppression requirement. The battery pack or the electric working machine can recognize that the discharge current should be reduced or stopped based on the fact that the instruction has been outputted. The electric working machine can reduce or stop the discharge current in various ways based on the recognition result. In this way, the fuse can be prevented from accidentally blowing.

[0047] One embodiment may include the following feature 9 in addition to or instead of at least one of the above features 1 to 8.

[0048] Feature 9: The discharge suppression requirement is satisfied based on the fuse temperature reaching a first temperature threshold (in other words, being higher than or equal to the first temperature threshold).

[0049] The first temperature threshold may be lower than the blown threshold. If the blown thresholds of the at least one fuse are different from each other, the first temperature threshold may be lower than a lowest blown threshold.

[0050] The battery pack having at least features 1 to 9 can correctly determine whether the discharge suppression requirement is satisfied.

[0051] In addition to or instead of at least one of the above features 1 to 9, one embodiment may further include the following feature 10.

[0052] Feature 10: The control circuit is configured to cancel the command based on (i) the command has been output or is being output, and (ii) the fuse temperature is lower than or equal to a second temperature threshold.

[0053] In other words, the control circuit may be configured to cancel the command after outputting the command based on the fact that the temperature of the fuse drops from the first temperature threshold to the second temperature threshold.

[0054] Releasing the instruction may include stopping outputting the instruction, or may include outputting another instruction to replace the instruction.

[0055] The battery pack having at least features 1 to 10 can suppress the discharge current from being excessively reduced or stopped.

[0056] In addition to or in place of at least one of the above features 1 to 9, one embodiment may further include the following feature 11. Furthermore, one embodiment may further include the following feature 12 in place of the above feature 10.

[0057] Feature 11: The electric working machine includes a manual switch, and the manual switch is manually operated by a user of the electric working machine to instruct the electric working machine to drive.

[0058] Feature 12: The control circuit is configured to release the instruction based on (i) the instruction has been output or is being output, (ii) the fuse temperature is lower than or equal to the second temperature threshold, and (iii) the manual switch has not been operated (i.e., has been released).

[0059] The battery pack having at least features 1 to 9, 11, and 12 can cancel the command at an appropriate timing.

[0060] If an embodiment has the above-mentioned features 9 and 10, or the above-mentioned features 9, 11, and 12, the embodiment may further have the following feature 13.

[0061] Feature 13: The second temperature threshold is lower than the first temperature threshold.

[0062] The battery pack having at least features 1 to 10 and 13, or the battery pack having at least features 1 to 9 and 11 to 13 can release the command at a more appropriate timing.

[0063] In addition to or instead of at least one of the above features 1 to 13, one embodiment may further include the following feature 14.

[0064] Feature 14: A substrate is provided, on which the at least one fuse and the temperature detector are assembled.

[0065] The battery pack having at least features 1 to 8 and 14 can facilitate installation of the at least one fuse and the temperature detector.

[0066] If an embodiment has the above-mentioned feature 14, the embodiment may further have at least one of the following features 15 to 17.

[0067] Feature 15: The substrate has a first surface and a second surface, and the second surface corresponds to a surface on the opposite side of the first surface.

[0068] Feature 16: The at least one fuse is assembled on the first surface.

[0069] Feature 17: The temperature detector is assembled on the second surface.

[0070] The second surface is opposite to the first surface via the substrate. That is, if the first surface is defined as the surface of the substrate, the second surface corresponds to the back surface of the substrate.

[0071] In the battery pack having at least features 1 to 8 and 14 to 17, the at least one fuse and the temperature detector can be efficiently assembled to the substrate.

[0072] If an embodiment has the above feature 16, the embodiment may also have at least one of the following features 18 and 19.

[0073] Feature 18: The at least one fuse includes a first fuse.

[0074] Feature 19: The temperature detector is at least partially opposed to the first fuse via the substrate. In other words, when the substrate is viewed from a direction perpendicular to the substrate (or the surface of the substrate), the temperature detector and the first fuse at least partially overlap.

[0075] In the battery pack having at least features 1 to 8 and 14 to 19, the temperature detector can accurately detect the fuse temperature.

[0076] If an embodiment has the above feature 18, the embodiment may also have at least one of the following features 20 to 22.

[0077] Feature 20: The at least one fuse further includes a second fuse.

[0078] Feature 21: The first fuse and the second fuse are arranged on the first surface with a gap therebetween.

[0079] Feature 22: The temperature detector is at least partially opposed to an intermediate region via the substrate. The intermediate region may be located between the first fuse and the second fuse on the first surface.

[0080] In the battery pack having at least features 1 to 8 and 14 to 22, the temperature detector can accurately detect the fuse temperature.

[0081] If an embodiment has the above feature 20, the embodiment may also have the following feature 23.

[0082] Feature 23: The temperature detector is at least partially opposite to (i) the first fuse and / or the second fuse, and (ii) the intermediate area, via the substrate.

[0083] In the battery pack having at least features 1 to 8 and 14 to 23, the temperature detector can accurately detect the fuse temperature.

[0084] In addition to or instead of at least one of the above features 1 to 23, one embodiment may further have the following feature 24.

[0085] Feature 24: An output terminal is provided, wherein the output terminal is configured to (i) be connected to an input terminal of the electric working machine based on the mounting portion being mounted on the electric working machine, and (ii) transmit the command to the input terminal via the output terminal.

[0086] The electric working machine may be configured to suppress or prevent the discharge current from being input from the battery to the electric working machine based on receipt of the command via the input terminal.

[0087] In the battery pack having at least features 1 to 8 and 24, the discharge current can be substantially suppressed or stopped on the electric working machine side.

[0088] If an embodiment has the above feature 24, the embodiment may also have the following feature 25.

[0089] Feature 25: The output terminal is located on the first surface.

[0090] One embodiment may provide a method of suppressing discharge current in a battery pack for an electric working machine, the method including at least one of the following features 26 to 27.

[0091] Feature 26: Detecting the temperature of a fuse. The fuse is located on a current path. The current path is configured so that the discharge current from a battery flows through the current path. The battery is located in the battery pack.

[0092] Feature 27: When the temperature satisfies a discharge suppression requirement, the discharge current is reduced or stopped. The discharge suppression requirement is required in order to reduce or stop the discharge current.

[0093] The method having features 26 to 27 can suppress accidental blowing of the fuse.

[0094] In addition to or instead of at least one of the above features 26 to 27, one embodiment may further include at least one of the following features 28 and 29.

[0095] Feature 28: The fuse is assembled to the first surface of the substrate.

[0096] Feature 29: A temperature detector is mounted on the second surface of the substrate. The temperature detector is configured to detect the temperature of the fuse. The second surface is located on the opposite side of the first surface.

[0097] In one embodiment, the above features 1 to 29 may be combined in any manner.

[0098] In one embodiment, any one of the above features 1 to 29 may be eliminated.

[0099] Examples of the electric working machine are various on-site electrical equipment used at work sites such as Sunday carpentry, manufacturing, gardening, and construction, which are configured to be driven by the battery, specifically, including electric tools for stone processing, metal processing, and wood processing, gardening working machines, and equipment for preparing the work site environment, more specifically, including electric blowers, electric hammers, electric hammer drills, electric drills, electric screwdrivers, electric wrenches, electric grinders, electric circular saws, electric reciprocating saws, electric jig saws, electric cutters, electric chainsaws, electric planers, electric nailers (including riveters), electric hedge trimmers, electric mowers, electric lawn trimmers, electric harvesters, electric cleaners, electric sprayers, electric sprinklers, electric dust collectors, sweeping robots (a robotic vacuum (or a robotic vacuum), battery-driven carts, battery-driven bicycles, etc. In addition to the above-mentioned equipment, the battery pack can also be detachably installed to the following electric working machines, such as a laser rangefinder (or laser rangefinder), a laser marking machine, a laser receiver for a laser marking machine, a wall-mounted scanner, a radio, a television, a speaker, an electric cold or warm box, an electric kettle, a coffee machine (or a coffee pot, or a coffee distiller), a microwave oven, a fan vest, a heating jacket, etc., and operate them.

[0100] In one embodiment, the control circuit may be integrated into a single electronic unit or a single electronic device or a single substrate.

[0101] In one embodiment, the control circuit may be a combination of two or more electronic circuits or a combination of two or more electronic units or a combination of two or more electronic devices separately provided in the battery pack.

[0102] In one embodiment, the control circuit may include a microcomputer (or a microcontroller, or a microprocessor), wired logic, an application-specific integrated circuit (ASIC), an application-specific standard product (ASSP), a programmable logic device (such as a field programmable gate array (FPGA), etc.), discrete electronic components and / or a combination of the above.

[0103] [2. Specific exemplary embodiments]

[0104] Hereinafter, exemplary embodiments of the present disclosure will be described.

[0105] [2-1. Implementation Method]

[0106] (2-1-1) Overall structure of the battery pack

[0107] like Figure 1 and Figure 2 As shown, the battery pack 10 of this embodiment includes a housing 1. The housing 1 has a substantially rectangular parallelepiped shape. The housing 1 includes an upper shell 2 and a lower shell 3. The upper shell 2 has a tray shape. The upper shell 2 opens downward. The lower shell 3 has a substantially rectangular parallelepiped shape. The lower shell 3 opens upward. Figure 1 and Figure 2 The upper housing 2 is shown in a state where the lower housing 3 is mounted. The housing 1 accommodates the battery 5 and the substrate 101 (see Figure 3 ).

[0108] The battery pack 10 is configured to supply power to the electric working machine 200 (see Fig. 9 ) supplies power and operates the electric working machine 200. Fig. 9 As shown, the electric working machine 200 has a positive device terminal 201 and a negative device terminal 202. The electric working machine 200 has one or more device auxiliary terminals. As just one example, the one or more device auxiliary terminals of this embodiment include a device DT terminal 204, a device TR terminal 205, and a device DS terminal 206.

[0109] The battery pack 10 is further configured to receive charging power from a charger (not shown) and charge the battery 5. The charger includes a charger positive terminal (not shown) and a charger negative terminal (not shown). The charger includes one or more charging auxiliary terminals. As just one example, the one or more charging auxiliary terminals of this embodiment include a charger CS terminal (not shown), a charger DT terminal (not shown), a charger TR terminal (not shown), and a charger DS terminal (not shown).

[0110] The battery pack 10 can be selectively mounted on various types of electric working machines (or battery-driven equipment). The battery pack 10 can supply power to the electric working machine on which the battery pack 10 is mounted, thereby operating the electric working machine. Various electric working machines include at least one of the various types of electric equipment for work sites described above. Fig. 9 The electric working machine 200 shown is an example of various types of electric working machines. At least from this section (2-1-1) to the next section (2-1-3), "electric working machine 200" can be understood as "an electric working machine to be installed or installed with a battery pack 10 among various types of electric working machines."

[0111] The battery 5 of this embodiment is a rechargeable battery that can be recharged repeatedly. For example, the battery 5 can be a lithium-ion battery. The battery 5 has a plurality of battery cells connected in series. The battery 5 can also be a primary battery. The rated voltage value of the battery 5 of this embodiment is, for example, 36V.

[0112] The upper housing 2 has a mounting portion 4 on its upper surface. The mounting portion 4 is detachably mounted on the electric working machine 200 or the charger. When the mounting portion 4 is mounted on the electric working machine 200, the battery pack 10 can supply current to the electric working machine 200. The current supplied from the battery pack 10 to the electric working machine 200 is hereinafter referred to as "discharge current". When the mounting portion 4 is connected to the charger, the battery pack 10 can receive a charging current from the charger. The charging current charges the battery 5.

[0113] The mounting portion 4 includes a first insertion port 11. When the mounting portion 4 is mounted on the electric working machine 200, the equipment positive terminal 201 is inserted into the first insertion port 11. When the mounting portion 4 is mounted on the charger, the charger positive terminal is inserted into the first insertion port 11.

[0114] The mounting portion 4 includes a second insertion port 12. When the mounting portion 4 is mounted on the electric working machine 200, the equipment negative terminal 202 is inserted into the second insertion port 12. When the mounting portion 4 is mounted on the charger, the charger negative terminal is inserted into the second insertion port 12.

[0115] The mounting portion 4 includes a third insertion port 13. When the mounting portion 4 is mounted on the electric working machine 200, the device DT terminal 204 is inserted into the third insertion port 13. When the mounting portion 4 is mounted on the charger, the charger CS terminal and the charger DT terminal are inserted into the third insertion port 13.

[0116] The mounting portion 4 includes a fourth insertion port 14. When the mounting portion 4 is mounted on the electric working machine 200, the device TR terminal 205 and the device DS terminal 206 are inserted into the fourth insertion port 14. When the mounting portion 4 is mounted on the charger, the charger TR terminal and the charger DS terminal are inserted into the fourth insertion port 14.

[0117] The first insertion opening 11 to the fourth insertion opening 14 all extend in the front-rear direction. The first insertion opening 11 to the fourth insertion opening 14 are arranged in order from left to right.

[0118] like Figure 2 As shown in the figure, the battery pack 10 includes a display unit 16. The display unit 16 displays the remaining capacity information indicating the remaining capacity of the battery 5 (hereinafter referred to as "battery remaining capacity"). In the present embodiment, the display unit 16 includes, for example, a first LED 16a, a second LED 16b, a third LED 16b, and a fourth LED 16d. The battery pack 10 includes a first switch 17. When the first switch 17 is manually operated (for example, pressed), the display unit 16 lights up in a manner corresponding to the battery remaining capacity.

[0119] like Figure 3 As shown, the battery pack 10 includes a printed wiring board (hereinafter simply referred to as a “substrate”) 101 and the above-mentioned battery 5 . Figure 3 The battery pack 10 is shown with the upper case 2 removed. The substrate 101 is housed in the upper case 2. The battery 5 is mainly housed in the lower case 3. The substrate 101 is arranged on the upper part of the battery 5. The substrate 101 has a substantially rectangular plate shape. As described below, a plurality of electronic components are mounted on the substrate 101.

[0120] (2-1-2) Substrate Configuration

[0121] like Figures 3 to 6 As shown, the substrate 101 has a first surface (or front surface) 101a and a second surface (or back surface) 101b. The first surface 101a faces the upper case 2, and the second surface 101b faces the battery 5.

[0122] The substrate 101 includes a positive terminal 21 and a negative terminal 22. The positive terminal 21 and the negative terminal 22 are conductors (e.g., metal). The positive terminal 21 is mounted at a first position on the first surface 101a, and the first position corresponds to the first insertion port 11. The negative terminal 22 is mounted at a second position on the first surface 101a, and the second position corresponds to the second insertion port 12.

[0123] When the device positive terminal 201 or the charger positive terminal is inserted into the first insertion port 11, the device positive terminal 201 or the charger positive terminal is mechanically and electrically connected to the positive terminal 21. When the device negative terminal 202 or the charger negative terminal is inserted into the second insertion port 12, the device negative terminal 202 or the charger negative terminal is mechanically and electrically connected to the negative terminal 22.

[0124] The substrate 101 has a CS terminal 23. The CS terminal 23 is a conductor (e.g., metal). The CS terminal 23 is mounted at the third position of the first surface 101a, and the third position corresponds to the third insertion port 13. When the charger CS terminal is inserted into the third insertion port 13, the charger CS terminal is mechanically and electrically connected to the CS terminal 23.

[0125] The battery pack 10 is configured to output a charge permission signal or a charge prohibition signal to the charger via the CS terminal 23. The charge permission signal permits the charger to charge the battery 5. The charge prohibition signal prohibits the charger from charging the battery 5.

[0126] The substrate 101 has a DT terminal (or a first communication terminal) 24, which is a conductor (e.g., metal), and is mounted at the fourth position of the first surface 101a, which corresponds to the third insertion port 13 but is different from the third insertion port 13. The DT terminal 24 is arranged at a position forward of the CS terminal 23 and is spaced apart from the CS terminal 23. When the device DT terminal 204 is inserted into the third insertion port 13, the device DT terminal 204 is mechanically and electrically connected to the DT terminal 24. When the charger DT terminal is inserted into the third insertion port 13, the charger DT terminal is mechanically and electrically connected to the DT terminal 24.

[0127] The battery pack 10 is configured to receive a switch signal (or a start switch signal) from the electric working machine 200 via the DT terminal 24. The switch signal indicates a manual switch (or a start switch) 213 of the electric working machine 200 (see Fig. 9 ) is turned on (for example, manually operated). The battery pack 10 is configured to output a connection signal via the DT terminal 24. The electric working machine 200 and the charger can recognize that the battery pack 10 is connected based on the connection signal from the battery pack 10.

[0128] The substrate 101 has a TR terminal (or serial communication terminal) 25. The TR terminal 25 is a conductor (e.g., metal). The TR terminal 25 is mounted at the fifth position of the first surface 101a, and the fifth position corresponds to the fourth insertion port 14. When the device TR terminal 205 is inserted into the fourth insertion port 14, the device TR terminal 205 is mechanically and electrically connected to the TR terminal 25. When the charger TR terminal is inserted into the fourth insertion port 14, the charger TR terminal is mechanically and electrically connected to the TR terminal 25.

[0129] The battery pack 10 is configured to perform serial communication with the electric working machine 200 or a charger via the TR terminal 25 .

[0130] The substrate 101 has a DS terminal (or a second communication terminal) 26. The DS terminal 26 is a conductor (e.g., metal). The DS terminal 26 is mounted at the 6th position on the first surface 101a. The 6th position corresponds to the 4th insertion port 14 and is different from the 5th position. The DS terminal 26 is arranged at a position forward of the TR terminal 25 and is spaced apart from the TR terminal 25. When the device DS terminal 206 is inserted into the 4th insertion port 14, the device DS terminal 206 is mechanically and electrically connected to the DS terminal 26. When the charger DS terminal is inserted into the 4th insertion port 14, the charger DS terminal is mechanically and electrically connected to the DS terminal 26.

[0131] The battery pack 10 is configured to output a discharge permission signal or a discharge prohibition signal to the electric working machine 200 via the DS terminal 26. The discharge permission signal permits the operation of the electric working machine 200. The discharge prohibition signal prohibits the operation of the electric working machine 200. The battery pack 10 receives the auxiliary voltage WK from the charger via the DS terminal 26.

[0132] The substrate 101 includes a control circuit 31. The control circuit 31 is mounted on the first surface 101a. The control circuit 31 includes a CPU (central processing unit), a memory, an input / output (I / O), and various peripheral circuits (such as an analog-to-digital converter). The memory includes semiconductor memories such as ROM (read-only memory), RAM (random access memory), and flash memory. The control circuit 31 performs various controls in the battery pack 10, including controlling the discharge and charge of the battery 5. The control circuit 31 of this embodiment adopts the form of a microprocessing unit (MPU).

[0133] The substrate 101 includes an analog front end (hereinafter referred to as "AFE") 32. The AFE 32 is mounted on the first surface 101a. The AFE 32 is an analog circuit.

[0134] The substrate 101 includes a first protection circuit 41 and a second protection circuit 42. When a predetermined abnormality occurs in the battery pack 10, the first protection circuit 41 and the second protection circuit 42 forcefully stop the discharge of the battery 5. The predetermined abnormality includes a state where the discharge of the battery 5 should be stopped. One of the first protection circuit 41 and the second protection circuit 42 may be omitted.

[0135] The first protection circuit 41 and the second protection circuit 42 are arranged on the first surface 101a at a predetermined interval from each other. In the present embodiment, the first protection circuit 41 and the second protection circuit 42 are both in the form of surface mount devices (SMD). However, the first protection circuit 41 and the second protection circuit 42 may also be in a form other than SMD.

[0136] The first protection circuit 41 has a package. Various electronic components and circuits included in the first protection circuit 41 are sealed in the package. The package includes, for example, resin or ceramic. The package has, for example, a substantially rectangular parallelepiped shape. At least a portion of the first protection circuit 41 is in contact with the first surface 101a. The first protection circuit 41 has a first opposing surface that is opposite to the first surface 101a. A portion or all of the first opposing surface may be in contact with the first surface 101a.

[0137] The second protection circuit 42 has the same configuration as the first protection circuit 41 , and is assembled in the same manner as the first protection circuit 41 .

[0138] like Figures 5 to 7 As shown, the substrate 101 includes a temperature detector 44. The temperature detector 44 is mounted on the second surface 101b. In this embodiment, the temperature detector 44 adopts the SMD method. However, the temperature detector 44 can also adopt a form different from the SMD. For example, the temperature detector 44 can include a temperature sensing element (such as a thermistor head) and a plurality of wires connected to the temperature sensing element.

[0139] The temperature detector 44 detects the temperature of the first protection circuit 41 and the second protection circuit 42, more specifically, the overall temperature of the two first fuses 41a, 41b and the two second fuses 42a, 42b described later (hereinafter referred to as "fuse temperature"). The temperature detector 44 includes a temperature sensing element capable of detecting temperature. In the present embodiment, the temperature detector 44 includes a thermistor.

[0140] Here, the area on the first surface 101a where the first protection circuit 41 is mounted is referred to as a first mounting area. The first mounting area may be, for example, an area opposite to the first protection circuit 41. For example, when the first protection circuit 41 is projected onto the first surface 101a in the vertical direction, the first mounting area may be an area projected onto the first surface 101a.

[0141] In addition, the area on the first surface 101a where the second protection circuit 42 is mounted is referred to as a second mounting area. The second mounting area may be, for example, an area opposite to the second protection circuit 42. For example, when the second protection circuit 42 is projected onto the first surface 101a in the vertical direction, the second mounting area may be an area projected onto the first surface 101a.

[0142] Moreover, if Figure 7 As shown, on the second surface 101 b , a first region 410 , a second region 420 , and an intermediate region 440 are defined.

[0143] The first region 410 corresponds exactly to the back side of the first mounting region. In other words, in a direction perpendicular to the substrate 101 (ie, the up-down direction), the first region 410 completely overlaps (ie, is consistent with) the first mounting region.

[0144] The second region 420 corresponds exactly to the back side of the second mounting region. In other words, in a direction perpendicular to the substrate 101, the second region 420 completely overlaps (ie, is consistent with) the second mounting region.

[0145] The middle area 440 is an area between the first area 410 and the second area 420. More precisely, the middle area 440 can be defined as an area where, for example, a specific line segment may exist. The specific line segment corresponds to a line segment connecting an arbitrary first point in the first area 410 and an arbitrary second point in the second area 420. The middle area 440 can be defined in any manner as long as it can be identified as an area between the first area 410 and the second area 420. For example, the middle area 440 can be an area between the first area 410 and the second area 420 in an area enclosed by a circumscribed rectangle circumscribing both the first area 410 and the second area 420.

[0146] like Figures 5 to 7 As shown, in this embodiment, the temperature detector 44 is located in the middle area 440. In addition, the temperature detector 44 is also located in the first area 410 and the second area 420. That is, the temperature detector 44 of this embodiment is at least partially overlapped on the first protection circuit 41 and the second protection circuit 42 in the vertical direction.

[0147] (2-1-3) Electrical structure of battery pack

[0148] Reference Figure 8 , the electrical structure of the battery pack 10 is described. As described above, the battery pack 10 of this embodiment includes the battery 5, the positive terminal 21, the negative terminal 22, the CS terminal 23, the DT terminal 24, the TR terminal 25, the DS terminal 26, the control circuit 31, the AFE 32, the display unit 16, and the first switch 17. The display unit 16 and the first switch 17 are connected to the control circuit 31.

[0149] The battery pack 10 includes a temperature detection circuit 43. The temperature detection circuit 43 includes the temperature detector 44 described above. The temperature detection circuit 43 is connected to the control circuit 31. The temperature detection circuit 43 outputs a fuse temperature signal to the control circuit 31. The fuse temperature signal indicates the fuse temperature detected by the temperature detector 44.

[0150] The battery pack 10 includes a positive electrode path 27 and a negative electrode path 28. The positive electrode path 27 electrically connects the positive electrode terminal 21 to the positive electrode of the battery 5. The negative electrode path 28 electrically connects the negative electrode terminal 22 to the negative electrode of the battery 5.

[0151] The battery pack 10 includes a current detection circuit 35. The current detection circuit 35 is provided on the negative electrode path 28, and outputs a current detection signal according to the magnitude of the battery current flowing through the negative electrode path 28. The battery current includes a discharge current or a charge current. The current detection circuit 35 of this embodiment includes a resistor (not shown) on the negative electrode path 28. The voltage between both ends of the resistor changes according to the magnitude of the battery current. The current detection signal indicates the magnitude of the voltage between both ends of the resistor. The current detection signal is input to the AFE 32.

[0152] The battery pack 10 includes a first thermistor 46 and a second thermistor 47. The first thermistor 46 and the second thermistor 47 are arranged, for example, near the battery 5 and are used to detect the temperature of the battery 5. The first thermistor 46 and the second thermistor 47 may be in contact with one of the plurality of battery cells, respectively. The first thermistor 46 outputs a first cell temperature signal Vce1 to the AFE 32. The first cell temperature signal Vce1 indicates a first battery temperature. The first battery temperature corresponds to the temperature detected by the first thermistor 46. The second thermistor 47 outputs a second cell temperature signal Vce2 to the AFE 32. The second cell temperature signal Vce2 indicates a second battery temperature. The second battery temperature corresponds to the temperature detected by the second thermistor 47.

[0153] AFE32 is capable of communicating with the control circuit 31. AFE32 follows the instructions from the control circuit 31 to detect the size of the voltage of each of the multiple battery cells (hereinafter referred to as "cell voltage"). AFE32 performs cell balancing processing according to the size of each cell voltage. Cell balancing processing is a process for equalizing the remaining capacity of multiple battery cells. AFE32 detects the temperature of the battery 5 based on the first cell temperature signal Vce1 and the second cell temperature signal Vce2. AFE32 detects the size of the battery current based on the current detection signal. AFE32 converts the size of each cell voltage, the temperature of the battery 5, and the size of the battery current into digital signals, respectively, and outputs the converted digital signals to the control circuit 31.

[0154] The AFE 32 determines whether to allow or prohibit charging of the battery 5 based on the magnitude of each cell voltage, the temperature of the battery 5, and the magnitude of the battery current. When the AFE 32 determines that charging of the battery 5 is permitted, the AFE 32 outputs a first charging permission signal to the control circuit 31 and the first signal output circuit 51. When the AFE 32 determines that charging of the battery 5 is prohibited, the AFE 32 outputs a first charging prohibition signal to the control circuit 31 and the first signal output circuit 51.

[0155] The battery pack 10 includes a filter 33. A first terminal of the filter 33 is connected to the positive electrode of the battery 5. A second terminal of the filter 33 is connected to the AFE 32. The filter 33 functions as a so-called low-pass filter. The filter 33 removes harmonic components from the voltage of the battery 5 (hereinafter referred to as "battery voltage"). The AFE 32 receives the battery voltage from the filter 33.

[0156] The battery pack 10 includes a battery voltage detection circuit 36. The battery voltage detection circuit 36 ​​detects the magnitude of the battery voltage and outputs a voltage detection signal to the control circuit 31. The voltage detection signal indicates the magnitude of the detected battery voltage.

[0157] The battery pack 10 includes a starter circuit 34. The starter circuit 34 includes a first diode D1, a first Zener diode D11, a second diode D2, and a second Zener diode D12. The first diode D1 includes an anode connected to the second end of the filter 33. The first diode D1 includes a cathode connected to the cathode of the first Zener diode D11. The first Zener diode D11 includes an anode connected to the AFE 32. The second diode D2 includes an anode connected to the cathode of the third diode D3 described below. The second diode D2 includes a cathode connected to the cathode of the second Zener diode D12. The second Zener diode D12 includes an anode connected to the AFE 32.

[0158] The anode of the first diode D1 receives the battery voltage from the filter 33. The anode of the second diode D2 receives the auxiliary voltage WK from the charger. More specifically, in this embodiment, the auxiliary voltage WK is input to the start circuit 34 from the DS terminal 26 via the third diode D3.

[0159] The start circuit 34 receives the battery voltage and / or the auxiliary voltage WK. The start circuit 34 outputs the battery voltage or the auxiliary voltage WK as a power start signal to the AFE 32. Specifically, if the battery voltage input to the start circuit 34 is greater than or equal to a specified voltage value, the battery voltage is output to the AFE 32 via the first diode D1 and the first Zener diode D11 as a power start signal. The magnitude greater than or equal to the specified voltage value corresponds to the magnitude that the first Zener diode D11 can break down. If the auxiliary voltage WK is input to the start circuit 34, the auxiliary voltage WK is output to the AFE 32 via the second diode D2 and the second Zener diode D12 as a power start signal.

[0160] The battery pack 10 includes a power supply circuit (not shown). The power supply circuit generates a DC power supply voltage Vc. The power supply voltage Vc operates each component in the battery pack 10. In the present embodiment, the power supply circuit is built into the AFE 32.

[0161] AFE32 has a voltage input port. The voltage input port receives the battery voltage from the filter 33. In AFE32, the battery voltage is input to the power supply circuit. Although not shown in the figure, the voltage input port is also connected to the auxiliary voltage line. The auxiliary voltage line is supplied with the auxiliary voltage WK. Therefore, the power supply circuit receives the battery voltage or the auxiliary voltage WK via the voltage input port. AFE32 receives the aforementioned power supply start signal. When the power supply circuit receives the power supply start signal during the stop operation, the power supply circuit generates a power supply voltage Vc from the battery voltage or the auxiliary voltage WK. The power supply voltage Vc is output from AFE32 and supplied to various components in the battery pack 10 including the control circuit 31.

[0162] In this embodiment, the control circuit 31 monitors the battery voltage based on the voltage detection signal from the battery voltage detection circuit 36. When the battery voltage is lower than a predetermined over-discharge threshold, the control circuit 31 outputs a shutdown command to the AFE 32. When the AFE 32 receives the shutdown command, the AFE 32 stops the operation of the power supply circuit. As a result, the generation of the power supply voltage Vc stops, and the control circuit 31 is shut down (i.e., the operation is completely stopped).

[0163] If the control circuit 31 is turned off and the magnitude of the battery voltage is lower than the specified voltage value, the power start signal based on the battery voltage will not be input to the power circuit. In this case, the off state will be maintained. On the other hand, while the control circuit 31 is turned off, if the battery pack 10 is connected to the charger and the auxiliary voltage WK is input from the charger, the auxiliary voltage WK and the power start signal based on the auxiliary voltage WK are input to the power circuit. As a result, the power supply voltage Vc is generated in the power circuit, and the control circuit 31 is started. It is possible that the battery 5 is charged by a power source different from the regular charger. In this case, the auxiliary voltage WK is not input to the battery pack 10. In this case, when the magnitude of the battery voltage is restored to above the specified voltage value, the power start signal based on the battery voltage is input to the AFE32. As a result, the power supply voltage Vc is generated, and the control circuit 31 is started. After starting, the control circuit 31 monitors and controls the charging of the battery 5 to ensure that the battery 5 does not become overcharged.

[0164] The battery pack 10 includes a second switch Tr1. In the present embodiment, the second switch Tr1 is in the form of a P-channel metal oxide semiconductor field effect transistor (MOSFET). The second switch Tr1 includes a source connected to the second end of the filter 33. The second switch Tr1 includes a drain connected to a detection circuit 56 described later. The second switch Tr1 includes a gate connected to the control circuit 31.

[0165] The control circuit 31 normally turns on the second switch Tr1. When the second switch Tr1 is turned on, the battery voltage is output from the drain of the second switch Tr1 via the filter 33 and the second switch Tr1. The battery voltage output from the drain is called the "notification voltage V_IN". The notification voltage V_IN is used to notify that the electric working machine 200 and the charger battery pack 10 are connected. When the control circuit 31 outputs a shutdown command, the control circuit 31 turns off the second switch Tr1. In this case, when the shutdown is released, the control circuit 31 turns on the second switch Tr1 again.

[0166] The control circuit 31 determines the battery pack state based on various input signals. The battery pack state corresponds to the state of the battery pack 10 (mainly the state of the battery 5). For example, the battery pack state includes: the magnitude of the discharge current, the magnitude of the charge current, the magnitude of the battery voltage, the state of the battery 5 represented by various information (various signals and / or data) from the AFE 32 (for example, the voltage of each cell, the temperature of the battery 5, etc.), the fuse temperature, etc.

[0167] The control circuit 31 determines whether to allow or prohibit charging of the battery 5 according to the battery pack state. When the control circuit 31 allows charging of the battery 5, the control circuit 31 outputs a second charge permission signal to the first signal output circuit 51. When the control circuit 31 prohibits charging of the battery 5, the control circuit 31 outputs a second charge prohibition signal to the first signal output circuit 51.

[0168] The control circuit 31 determines whether to allow the battery 5 to discharge or prohibit the battery 5 from discharging according to the battery pack state. In the present embodiment, one of the conditions for allowing discharge includes that the manual switch 213 is turned on. If the control circuit 31 allows discharge, the control circuit 31 outputs a discharge permission signal to the second signal output circuit 66 described later. If the control circuit 31 prohibits discharge, the control circuit 31 outputs a discharge prohibition instruction to the second signal output circuit 66.

[0169] The battery pack 10 includes the first signal output circuit 51. The first signal output circuit 51 is connected to the CS terminal 23. The first signal output circuit 51 receives the first charge permission signal or the first charge prohibition signal from the AFE 32, and receives the second charge permission signal or the second charge prohibition signal from the control circuit 31. When the first signal output circuit 51 receives the first charge permission signal and the second charge permission signal, the first signal output circuit 51 outputs the charge permission signal to the charger via the CS terminal 23. When the first signal output circuit 51 receives the first charge prohibition signal or the second charge prohibition signal, the first signal output circuit 51 outputs the charge prohibition signal to the charger via the CS terminal 23.

[0170] If the charger receives a charge permission signal from the battery pack 10, the charger supplies a charge current to the battery pack 10, thereby charging the battery 5. If the charger receives a charge prohibition signal from the battery pack 10, the charger does not supply a charge current to the battery pack 10.

[0171] The battery pack 10 includes the above-mentioned detection circuit 56 . The detection circuit 56 is connected to the DT terminal 24 .

[0172] The detection circuit 56 detects whether the battery pack 10 is connected to the electric working machine 200 or the charger based on the signal input from the DT terminal 24. The detection circuit 56 notifies the control circuit 31 of the detection result.

[0173] The detection circuit 56 receives the switch signal from the electric working machine 200 via the DT terminal 24. The detection circuit 56 detects whether the manual switch 213 is turned on based on the switch signal. The detection circuit 56 notifies the control circuit 31 of the detection result.

[0174] The detection circuit 56 receives the notification voltage V_IN. If the detection circuit 56 receives the notification voltage V_IN, the detection circuit 56 outputs the connection signal via the DT terminal 24. If the detection circuit 56 does not receive the notification voltage V_IN, the detection circuit 56 does not output the connection signal.

[0175] The battery pack 10 includes a communication circuit 61. The communication circuit 61 is connected to the TR terminal 25. The communication circuit 61 performs serial communication with the electric working machine 200 or the charger via the TR terminal 25. The communication circuit 61 can be configured to perform data communication according to a communication standard such as a universal asynchronous receiver / transmitter (UART). The control circuit 31 transmits various data via the communication circuit 61 as needed. When the communication circuit 61 receives data from the electric working machine 200 or the charger, the communication circuit 61 outputs the data to the control circuit 31.

[0176] The battery pack 10 includes a second signal output circuit 66 and a third diode D3. The second signal output circuit 66 and the third diode D3 are connected to the DS terminal 26. As described above, the third diode D3 receives the auxiliary voltage WK from the charger and outputs the auxiliary voltage WK to the starter circuit 34.

[0177] When the second signal output circuit 66 receives a discharge permission command from the control circuit 31, the second signal output circuit 66 outputs a discharge permission signal to the electric working machine 200 via the DS terminal 26. When the second signal output circuit 66 receives a discharge prohibition command from the control circuit 31, the second signal output circuit 66 outputs a discharge prohibition signal to the electric working machine 200 via the DS terminal 26.

[0178] If the electric working machine 200 receives a discharge permission signal from the battery pack 10, the electric working machine 200 operates using the battery power of the battery pack 10. If the electric working machine 200 receives a discharge prohibition signal from the battery pack 10, the battery power consumption is stopped (or suppressed). Thus, the discharge from the battery 5 to the electric working machine 200 is stopped (or suppressed).

[0179] When a charge cannot be stopped abnormality or a discharge cannot be stopped abnormality occurs, the control circuit 31 outputs a protection signal to the protection unit 40. The charge cannot be stopped abnormality corresponds to that the charging current does not stop even if the second charge prohibition signal is output. The discharge cannot be stopped abnormality corresponds to that the discharge current does not stop even if the discharge prohibition instruction is output. The protection signal forcibly stops (or inhibits) the charging or discharging of the battery 5.

[0180] The protection unit 40 is disposed on the positive electrode path 27, and the protection unit 40 turns on or off the positive electrode path 27. The protection unit 40 normally turns on the positive electrode path 27. The battery current flows through the protection unit 40. On the other hand, if the above-mentioned predetermined abnormality occurs, the protection unit 40 cuts off the positive electrode path 27. In the present embodiment, the predetermined abnormality includes: (i) the magnitude of the battery current reaches a predetermined abnormal level, or (ii) a protection signal is input from the control circuit 31. The abnormal level refers to a level that will not occur or is less likely to occur during normal use. For example, an abnormal level of battery current may occur because the positive terminal 21 and the negative terminal 22 are both short-circuited to each other or the positive terminal 21 and the negative terminal 22 are both in a state close to being short-circuited to each other.

[0181] The protection unit 40 includes a first protection circuit 41 and a second protection circuit 42. In the present embodiment, the first protection circuit 41 and the second protection circuit 42 are connected in parallel to each other and provided on the positive electrode path 27.

[0182] The first end of the first protection circuit 41 and the first end of the second protection circuit 42 are connected to the positive electrode of the battery 5 via a portion of the positive electrode path 27. The second end of the first protection circuit 41 and the second end of the second protection circuit 42 are connected to the positive electrode terminal 21 via another portion of the positive electrode path 27.

[0183] The first protection circuit 41 includes two first fuses 41a and 41b connected in series. The first end of the first fuse 41a electrically corresponds to the first end of the first protection circuit 41. The second end of the first fuse 41a is connected to the first end of the first fuse 41b. The second end of the first fuse 41b electrically corresponds to the second end of the first protection circuit 41.

[0184] When the discharge current or the charging current reaches the above-mentioned abnormal level, the two first fuses 41a and 41b will melt by themselves due to the Joule heat generated by the discharge current or the charging current. As a result, the positive electrode path 27 is mechanically and electrically cut off, so that the battery 5 is in a state where it cannot be discharged or charged. In addition, in this embodiment, the discharge current and the charging current are each shunted 1 / 2 to the first protection circuit 41 and the second protection circuit 42 in the protection unit 40. Therefore, in more detail, the two first fuses 41a and 41b will melt due to the discharge current or the charging current shunted to the first protection circuit 41.

[0185] The first protection circuit 41 includes a first heater 41c. The first heater 41c is connected to the second end of the first fuse 41a and a protection signal output port (not shown) of the control circuit 31. The protection signal output port outputs a protection signal.

[0186] The first heater 41c of this embodiment includes two first resistors connected in parallel. The first ends of the two first resistors are connected to the second ends of the first fuse 41a. The second ends of the two first resistors are connected to the protection signal output ports of the control circuit 31.

[0187] When a protection signal is input from the control circuit 31 to the first protection circuit 41, current flows into the first heater 41c, so that the first heater 41c generates heat (i.e., the two first resistors generate heat). In the present embodiment, the protection signal is, for example, a low-level signal. In other words, in the present embodiment, the output of the protection signal means that the potential of the protection signal output port is set to a reference ground (Ground) or a potential close to the reference ground. Therefore, when the protection signal is output, a discharge current flows from the battery 5 to the first heater 41c via the first fuse 41a, or a charging current flows from the positive terminal 21 to the first heater 41c via the first fuse 41b. As a result, the first heater 41c generates heat. The heat generated by the first heater 41c at this time reaches a level that can melt the first fuses 41a and 41b. Therefore, the first fuses 41a and 41b are melted by the heat generated by the first heater 41c, thereby cutting off the positive electrode path 27.

[0188] In the present embodiment, the second protection circuit 42 has the same configuration as the first protection circuit 41, and operates in the same manner as the first protection circuit 41. That is, the second protection circuit 42 includes a second fuse 41a and a second fuse 42b connected in series with each other. The first end of the second fuse 42a electrically corresponds to the first end of the second protection circuit 42. The second end of the second fuse 42a is connected to the first end of the second fuse 42b. The second end of the second fuse 42b electrically corresponds to the second end of the second protection circuit 42. The functions of the second fuse 42a and the second fuse 42b are the same as those of the first fuse 41a and the first fuse 41b of the first protection circuit 41.

[0189] The second protection circuit 42 includes a second heater 42c. The second heater 42c includes two second resistors connected in parallel to each other. The first ends of the two second resistors are respectively connected to the second ends of the second fuse 42a. The second ends of the two second resistors are respectively connected to the protection signal output port. The function of the second heater 42c is the same as that of the first heater 41c.

[0190] Therefore, when (i) the discharge current or the charge current reaches the abnormal level, or (ii) a protection signal is output from the control circuit 31 , the first fuses 41 a , 41 b and the second fuses 42 a , 42 b are blown, thereby disconnecting the positive electrode path 27 .

[0191] The control circuit 31 receives a fuse temperature signal from the temperature detection circuit 43. The control circuit 31 obtains the fuse temperature according to the fuse temperature signal. When discharging from the battery 5 to the electric working machine 200, if the fuse temperature has satisfied the discharge suppression requirement, the control circuit 31 performs a discharge suppression process. The discharge suppression requirement is required to suppress or stop the discharge of the battery 5. Satisfying the discharge suppression requirement corresponds to the fuse temperature being at a level at which further increase should be suppressed. In the present embodiment, the discharge suppression requirement includes the fuse temperature reaching the first temperature threshold. In other words, the discharge suppression requirement is satisfied based on the fuse temperature having reached the first temperature threshold.

[0192] The main purpose of the discharge suppression process is to suppress the further increase of the fuse temperature. The discharge suppression process can be any process that can suppress the increase of the fuse temperature. The discharge suppression process of this embodiment includes outputting a discharge prohibition signal to the electric working machine 200, thereby stopping the consumption of the battery power in the electric working machine 200 (and thus stopping the discharge current).

[0193] Specifically, in the discharge suppression process, the control circuit 31 outputs a discharge prohibition instruction to the second signal output circuit 66. The second signal output circuit 66 outputs a discharge prohibition signal to the electric working machine 200 in response to receiving the discharge prohibition instruction. In response to the discharge prohibition signal received from the battery pack 10, the electric working machine 200 stops consuming battery power. After the fuse temperature reaches the first temperature threshold, if the suppression release requirement is met, the control circuit 31 stops the discharge suppression process. Specifically, the control circuit 31 stops outputting the discharge prohibition instruction. When the output of the discharge prohibition instruction is stopped, the output of the discharge prohibition signal is also stopped. The suppression release requirement is satisfied based on (i) the fuse temperature drops below the second temperature threshold and (ii) the manual switch 213 of the electric working machine 200 is closed. After the control circuit 31 stops outputting the discharge prohibition instruction, if the manual switch 213 is opened, the control circuit 31 outputs a discharge permission instruction as long as the state is not where discharge should be prohibited.

[0194] The first temperature threshold is set to be lower than the melting threshold. The melting threshold corresponds to the lowest temperature at which the first fuse 41a, 41b and the second fuse 42a, 42b can be melted. Therefore, even if the temperature of the first fuse 41a reaches the first temperature threshold, the first fuse 41a will not melt (or the possibility of melting is low). The first fuse 41b and the second fuse 42a, 42b are also the same. The first temperature threshold is set to stop the discharge before the first fuse 41a, 41b and the second fuse 42a, 42b melt. Specifically, the first temperature threshold can be set separately according to the specifications (such as rated current value) of the first fuse 41a, 41b and the second fuse 42a, 42b. The second temperature threshold is lower than the first temperature threshold. However, the second temperature threshold can also be the same as the first temperature threshold.

[0195] The discharge suppression process may be any process capable of suppressing (or reducing) or stopping the discharge current. For example, the discharge suppression process may include outputting a suppression instruction to the electric working machine 200. More specifically, the control circuit 31 may output a suppression instruction to the communication circuit 61, for example. In this case, the communication circuit 61 sends the suppression instruction to the electric working machine 200 via the TR terminal 25 according to the suppression instruction received from the control circuit 31. The electric working machine 200 reduces or stops the discharge current from the battery 5 to the electric working machine 200 according to the suppression instruction received from the battery pack 10.

[0196] The suppression instruction may include upper limit information indicating an upper limit value of the discharge current. In this case, the electric working machine 200 may control consumption of the battery power so that the magnitude of the discharge current is less than or equal to the upper limit value.

[0197] (2-1-4) Structure of electric working machine

[0198] Reference Fig. 9 The schematic configuration of the electric working machine 200 according to the present embodiment will be described. The electric working machine 200 includes a device positive electrode terminal 201 , a device negative electrode terminal 202 , a device DT terminal 204 , a device TR terminal 205 , and a device DS terminal 206 .

[0199] The electric working machine 200 includes a motor 211. The motor 211 drives a driven tool (not shown) mounted on the electric working machine 200. The driven tool has a shape adapted to the purpose of the electric working machine 200. For example, the driven tool may include a tool head (e.g., a screwdriver head, a drill bit). The tool head may be used for drilling a hole in a workpiece and / or tightening a screw into a workpiece.

[0200] The electric working machine 200 includes a manual switch 213. The manual switch 213 is opened by being manually operated (for example, pulled) by a user of the electric working machine 200.

[0201] The electric working machine 200 includes a controller 212. The controller 212 is connected to the device positive terminal 201 and the device negative terminal 202. The controller 212 receives battery power from the battery pack 10. The controller 212 converts the battery power into driving power. The driving power can drive the motor 211. The controller 212 supplies the driving power to the motor 211. The motor 211 is driven by receiving the driving power.

[0202] The controller 212 is connected to the device DT terminal 204, the device TR terminal 205, and the device DS terminal 206. The controller 212 detects whether the manual switch 213 is turned on, and outputs a switch signal corresponding to the detection result via the device DT terminal 204. The controller 212 performs serial communication with the battery pack 10 via the device TR terminal 205. The controller 212 receives a discharge permission signal or a discharge prohibition signal from the battery pack 10 via the device DS terminal 206.

[0203] Controller 212 outputs driving power to motor 211 based on receiving the discharge permission signal and manual switch 213 being turned on, thereby driving motor 211. If controller 212 receives the discharge prohibition signal, driving power is not output even if manual switch 213 is turned on.

[0204] If the controller 212 has received or is receiving the discharge prohibition signal, the controller 212 can completely stop consuming the battery power. If the electric working machine 200 has received or is receiving the discharge prohibition signal, the electric working machine 200 can completely stop consuming the battery power.

[0205] The controller 212 can reduce or stop the consumption of the battery power according to the received suppression command. When the suppression command includes the upper limit value, the controller 212 can control the power consumption of the electric working machine 200 so that the discharge current does not exceed the upper limit value.

[0206] (2-1-5) Control example of the control circuit corresponding to the fuse temperature.

[0207] Fig.10 An example of the operation of the control circuit 31 when the battery pack 10 is discharged to the electric working machine 200 is shown.

[0208] At time t0, the discharge current has been supplied from the battery pack 10 to the electric working machine 200, and the motor 211 is being driven. After time t0, the load applied to the motor 211 increases, so that the current flowing into the motor 211 increases (ie, the discharge current increases). As a result, the fuse temperature gradually rises.

[0209] At time t1, the fuse temperature reaches the first temperature threshold Th1. At time t1, the control circuit 31 outputs a discharge prohibition instruction according to the fact that the fuse temperature reaches the first temperature threshold Th1. As a result, the controller 212 of the electric working machine 200 stops supplying power to the motor 211. At this time, the controller 212 can completely stop consuming the battery power. Through the above operation of the electric working machine 200, the discharge from the battery 5 to the electric working machine 200 stops. As a result, the fuse temperature drops.

[0210] At time t2, the fuse temperature drops to the second temperature threshold Th2. At this time, if the manual switch 213 of the electric working machine 200 is turned off, the control circuit 31 stops the discharge prohibition command.

[0211] (2-1-6) Fuse temperature monitoring process

[0212] The above operation of the control circuit 31 is realized by the control circuit 31 (specifically, the CPU) executing a main process (not shown). The program of the main process is stored in the memory. The control circuit 31 executes the main process according to the program.

[0213] The main processing includes Fig.11 The fuse temperature monitoring process shown. The fuse temperature monitoring process is executed cyclically within a predetermined control period.

[0214] When the control circuit 31 starts the fuse temperature monitoring process, the control circuit 31 determines in S110 whether the abnormality flag has been set. The abnormality flag is set in S130. If the abnormality flag is not set, the main process proceeds to S120.

[0215] In S120, the control circuit 31 determines whether the fuse temperature is higher than or equal to the first temperature threshold. If the fuse temperature is lower than the first temperature threshold, the control circuit 31 terminates the fuse temperature monitoring process. If the fuse temperature is higher than or equal to the first temperature threshold, the main process enters S130.

[0216] In S130, the control circuit 31 sets an abnormality flag. The control circuit 31 further performs the above-mentioned discharge suppression process. Thus, the discharge of the battery 5 is suppressed or stopped. The abnormality flag indicates whether the discharge suppression process is being performed, in other words, whether the discharge suppression process is in a state where the discharge suppression process should be performed. After the process of S130 is completed, the control circuit 31 ends the fuse temperature monitoring process.

[0217] In S110, if the abnormality flag is set, the main process enters S140. In S140, the control circuit 31 determines whether the fuse temperature is lower than or equal to the second temperature threshold. If the fuse temperature is higher than the second temperature threshold, the main process enters S130. In this case, the setting of the abnormality flag is maintained, and the discharge suppression process is continued. If the fuse temperature is lower than or equal to the second temperature threshold, the main process enters S150.

[0218] In S150, the control circuit 31 determines whether the manual switch 213 is turned off. If the manual switch 213 is turned on, the main process proceeds to S130. If the manual switch 213 is turned off, the main process proceeds to S160.

[0219] In S160, the control circuit 31 clears the abnormality flag. The control circuit 31 further stops the discharge suppression process. Thus, the discharge suppression or stop based on the fuse temperature is released.

[0220] (2-1-7) Display unit control

[0221] The control of the display unit 16 performed by the control circuit 31 is described. The control circuit 31 calculates the remaining battery capacity. The remaining battery capacity can be calculated in any manner. In the present embodiment, for example, the control circuit 31 accumulates (i.e., cumulatively adds) the current values ​​detected by the current detection circuit 35 to calculate the current cumulative value. The control circuit 31 calculates the remaining battery capacity based on the current cumulative value.

[0222] In more detail, the control circuit 31 periodically learns (i.e., calculates) the full charge capacity of the battery 5, for example. Hereinafter, the learned full charge capacity is referred to as "FCC". The control circuit 31 calculates the remaining battery capacity based on the currently calculated FCC and the current accumulated value. For example, the FCC can be calculated based on the current accumulated value and the battery voltage.

[0223] The control circuit 31 further compares the calculated FCC with the degradation fault detection threshold FCC_CDI. If the FCC is lower than or equal to FCC_CDI, the control circuit 31 increases the count variable of the degradation detection counter by, for example, a predetermined value. The control circuit 31 can determine that the battery 5 has degraded (in other words, a fault has occurred) based on the count variable reaching a specified value. The degradation of the battery 5 can mean that the battery 5 is in a state where it is impossible to discharge from the battery 5 and / or charge the battery 5.

[0224] The control circuit 31 periodically loops the following operations: (i) calculating the current cumulative value, (ii) learning the FCC based on the calculated current cumulative value and the battery voltage, etc., and (iii) determining the degradation of the battery 5 based on the comparison between the FCC and FCC_CDI.

[0225] When the first switch 17 is operated, the control circuit 31 acquires the currently calculated remaining battery capacity and lights up the display unit 16 in a pattern corresponding to the remaining battery capacity. Fig.12 An example of the lighting pattern is shown.

[0226] like Fig.12 As shown, when the battery 5 is in a normal state, the lighting mode of the display unit 16 will undergo four different changes according to the state of charge (SOC) of the battery 5. The normal state corresponds to a state where the FCC is greater than FCC_CDI. In other words, the normal state corresponds to a state where the battery 5 is not degraded or is less degraded. In further other words, the normal state corresponds to a state where the battery 5 is neither determined to be faulty nor close to being faulty. The SOC is calculated based on the remaining battery capacity. For example, the SOC can be calculated by dividing the current remaining battery capacity by the current FCC.

[0227] Under normal circumstances, the display unit 16 lights up in the following pattern.

[0228] (i) If the SOC is 70% or more, the first LED 16a to the fourth LED 16d are turned on.

[0229] (ii) If the SOC is greater than or equal to 50% and less than 70%, the first to third LEDs 16a to 16c are turned on.

[0230] (iii) If the SOC is 25% or more and less than 50%, the first LED 16a and the second LED 16b are turned on.

[0231] (iv) If the SOC is less than 25%, the first LED 16a is turned on.

[0232] On the other hand, if the battery 5 is in a degraded state, the lighting pattern of the indicator light 16 changes in two ways depending on the SOC. The degraded state corresponds to a state where the FCC is less than or equal to FCC_CDI. In other words, the degraded state corresponds to a state where the degradation of the battery 5 is aggravated. In further other words, the degraded state corresponds to a state where it is estimated (or can be estimated) that the battery 5 is close to failure.

[0233] In the degraded state, the display unit 16 lights up in the following pattern.

[0234] (i) If the SOC is 25% or more, the first LED 16a and the second LED 16b are turned on.

[0235] (ii) If the SOC is less than 25%, the first LED 16a is turned on.

[0236] That is, in the degraded state, even if the battery 5 is fully charged, only the first LED 16a and the second LED 16b are lit. Therefore, the user can recognize that the battery 5 is degraded by the fact that the third LED 16c and the fourth LED 16d are not lit even if the battery 5 is charged for a long time.

[0237] (2-1-8) Correspondence of words

[0238] In the above-mentioned embodiment, the positive electrode path 27 is equivalent to an example of a current path in the summary of the embodiment. One of the two first fuses 41a and 41b is equivalent to an example of a first fuse in the summary of the embodiment. One of the two second fuses 42a and 42b is equivalent to an example of a second fuse in the summary of the embodiment. The TR terminal 25 or the DS terminal 26 is equivalent to an example of an output terminal in the summary of the embodiment. The device TR terminal 205 or the device DS terminal 206 is equivalent to an example of an input terminal in the summary of the embodiment. The discharge prohibition instruction or the discharge prohibition signal is equivalent to an example of an instruction in the summary of the embodiment. When the suppression instruction is output to the communication circuit 61, the suppression instruction is equivalent to an example of an instruction in the summary of the embodiment.

[0239] [2-2. Other embodiments]

[0240] The present disclosure is not limited to the above-described embodiment, and can be implemented with various modifications as described below.

[0241] (3-1) For example, Figure 7The temperature detector 44 in the embodiment may be located on the first region 410 and the middle region 440, but not on the second region 420. In this case, the temperature detector 44 may be located entirely on the first region 410 or the middle region 440. Alternatively, a portion of the temperature detector 44 may extend outside the first region 410 and the middle region 440.

[0242] For example, the temperature detector 44 may be located on the second region 420 and the middle region 440, but not on the first region 410. In this case, the temperature detector 44 may be located entirely on the second region 420 or the middle region 440. Alternatively, a portion of the temperature detector 44 may extend outside the second region 420 and the middle region 440.

[0243] For example, the temperature detector 44 may be located in the first region 410, but not in the second region 420 or the intermediate region 440. In this case, the temperature detector 44 may be located entirely in the first region 410. Alternatively, a portion of the temperature detector 44 may extend outside the first region 410.

[0244] For example, the temperature detector 44 may be located in the second region 420 but not in the first region 410 and the intermediate region 440. In this case, the entire temperature detector 44 may be located in the second region 420. Alternatively, a portion of the temperature detector 44 may extend outside the second region 420.

[0245] For example, the temperature detector 44 may be located in the middle region 440, but not in the first region 410 and the second region 420. In this case, the temperature detector 44 may be located entirely in the middle region 440. Alternatively, a portion of the temperature detector 44 may extend beyond the middle region 440. In this case, the temperature detector 44 may be selected according to the size of the middle region 440, or conversely, the middle region 440 may be provided according to the size of the temperature detector 44.

[0246] (3-2) Fig.13 and Fig.14 As shown, the protection part 40 may include, for example, a protection circuit (first protection circuit 41). In this case, the temperature detector 44 may be disposed opposite to the first protection circuit 41 via the substrate 101. In other words, the temperature detector 44 may be located on the first region 410 of the second surface 101b. Fig.13 and Fig.14 In the embodiment of the present invention, the temperature detector 44 is entirely located in the first region 410 . However, part or the entirety of the temperature detector 44 may be located outside the first region 410 .

[0247] (3-3) The protection section 40 may include three or more protection circuits. For example, in addition to the first protection circuit 41 and the second protection circuit 42, a third protection circuit may be provided on the first surface 101a. In this case, the area on the first surface 101a where the third protection circuit is mounted is referred to as the third mounting area, and the area on the second surface 101b that is located on the front and back sides of the third mounting area is referred to as the third area.

[0248] In this case, in addition to the intermediate region 440 , or instead of the intermediate region 440 , the temperature detector 44 may be located in an additional first intermediate region between the third region and the first region 410 and / or an additional second intermediate region between the third region and the second region 420 .

[0249] The temperature detector 44 may be located on the first region 410 , the second region 420 , and / or the third region. In other words, the temperature detector 44 may be opposed to at least one of the three or more protection circuits via the substrate 101 .

[0250] (3-4) Fig.15 As shown, the temperature detector 44 may be located on the first surface 101a. In other words, the temperature detector 44 may be located on the surface on which the protection portion 40 (specifically, the first protection circuit 41 and the second protection circuit 42) are mounted. Fig.15 The example in which the temperature detector 44 is arranged between the first protection circuit 41 and the second protection circuit 42 is shown. In this case, the first protection circuit 41 and / or the second protection circuit 42 may be in contact with the temperature detector 44 or may be spaced apart from the temperature detector 44.

[0251] (3-5) The first surface 101a and the second surface 101b may each have a protection circuit. For example, the first protection circuit 41 may be located on the first surface 101a, and the second protection circuit 42 may be located on the second surface 101b.

[0252] (3-6) The first protection circuit 41, the second protection circuit 42, and the temperature detector 44 may have any form or shape. For example, the first protection circuit 41, the second protection circuit 42, and / or the temperature detector 44 may have a shape other than a rectangular parallelepiped. In addition, the first protection circuit 41 and / or the second protection circuit 42 may have a shape other than SMD.

[0253] (3-7) The first protection circuit 41 may include one fuse or three or more fuses. The same applies to the second protection circuit 42.

[0254] (3-8) The first heater 41c may include one first resistor or three or more first resistors. The second heater 42c may include one second resistor or three or more second resistors.

[0255] (3-9) The first protection circuit 41 may not include the first heater 41c. The second protection circuit 42 may not include the second heater 42c.

[0256] (3-10) A heat dissipation component may be assembled near the first protection circuit 41 and the second protection circuit 42. The heat dissipation component can suppress the temperature rise of the first protection circuit 41 and / or the second protection circuit 42. The heat dissipation component dissipates the heat conducted from the first protection circuit 41 and / or the second protection circuit 42 to the heat dissipation component into space.

[0257] For example Fig.16 As shown, the heat dissipation component may include two copper plates 90, 91. Fig.16 In the embodiment, two copper plates 90 and 91 are assembled on the first surface 101a of the substrate 101. The heat dissipation component may have only one copper plate or may have three or more copper plates. The heat dissipation component may be in a form different from the copper plate. The heat dissipation component may have any shape and material that can function as a heat sink.

[0258] (3-11) The discharge suppression process may include cutting off the positive path 27 or the negative path 28 in the battery pack 10. Specifically, the battery pack 10 may include a path cutoff switch provided on the positive path 27. The path cutoff switch connects or disconnects the positive path 27. The control circuit 31 may open the path cutoff switch under normal circumstances to connect the positive path 27. During the discharge suppression process, the control circuit 31 may close the path cutoff switch to disconnect the positive path 27. The path cutoff switch may also be provided on the negative path 28.

[0259] (3-12) Multiple functions of one constituent element in the above-mentioned embodiment can be realized by multiple constituent elements, or one function of one constituent element can be realized by multiple constituent elements. In addition, multiple functions of multiple constituent elements can be realized by one constituent element, or one function realized by multiple constituent elements can be realized by one constituent element. In addition, part of the composition of the above-mentioned embodiment can be omitted. In addition, at least part of the composition of the above-mentioned embodiment can be added to the composition of other above-mentioned embodiments, and at least part of the composition of the above-mentioned embodiment can be replaced with the composition of other above-mentioned embodiments.

Claims

1. A battery pack for an electric working machine, characterized in that: have: A battery, the battery having a positive electrode and a negative electrode; a mounting portion configured to be detachably mounted on an electric working machine, wherein the electric working machine is driven by receiving electric power from the battery; a current path configured to (i) be connected to the positive electrode or the negative electrode and (ii) allow a discharge current to flow from the battery to the electric working machine; at least one fuse, the at least one fuse being configured to (i) be located on the current path and (ii) melt to cut off the current path; a temperature detector configured to output a temperature signal representing a fuse temperature corresponding to a temperature of the at least one fuse; as well as A control circuit, wherein the control circuit is configured to obtain the fuse temperature according to the temperature signal, and output an instruction for reducing or stopping the discharge current based on the obtained fuse temperature having satisfied a discharge suppression requirement, wherein the discharge suppression requirement is required in order to reduce or stop the discharge current.

2. The battery pack for an electric working machine according to claim 1, characterized in that: The discharge suppression requirement is met according to the fuse temperature reaching the first temperature threshold.

3. The battery pack for an electric working machine according to claim 2, characterized in that: The control circuit is configured to cancel the command based on (i) the command has been output or is being output, and (ii) the fuse temperature is lower than or equal to a second temperature threshold.

4. The battery pack for an electric working machine according to claim 3, characterized in that: The electric working machine includes a manual switch configured to be manually operated by a user of the electric working machine to instruct the electric working machine to drive. The control circuit is configured to cancel the command in response to (i) the command having been output or being output, (ii) the fuse temperature being lower than or equal to a second temperature threshold, and (iii) the manual switch being not operated.

5. The battery pack for an electric working machine according to claim 3 or 4, characterized in that: The second temperature threshold is lower than the first temperature threshold.

6. The battery pack for an electric working machine according to any one of claims 1 to 5, characterized in that: The battery pack for an electric working machine further includes a substrate on which the at least one fuse and the temperature detector are assembled.

7. The battery pack for an electric working machine according to claim 6, characterized in that: The substrate has a first surface and a second surface, the second surface corresponding to a surface on the opposite side of the first surface, The at least one fuse is assembled on the first surface, The temperature detector is assembled on the second surface.

8. The battery pack for an electric working machine according to claim 7, characterized in that: The at least one fuse comprises a first fuse, The temperature detector at least partially faces the first fuse via the substrate.

9. The battery pack for an electric working machine according to claim 8, characterized in that: The at least one fuse further comprises a second fuse, The first fuse and the second fuse are arranged on the first surface with a distance therebetween. The temperature detector is at least partially opposed to an intermediate region via the substrate, and the intermediate region is located between the first fuse and the second fuse on the first surface.

10. The battery pack for an electric working machine according to claim 9, characterized in that: The temperature detector is at least partially opposed to (i) the first fuse and / or the second fuse, and (ii) the intermediate region, via the substrate.

11. The battery pack for an electric working machine according to any one of claims 1 to 10, characterized in that: The battery pack for an electric working machine further includes an output terminal configured to (i) be connected to an input terminal of the electric working machine when the mounting portion is mounted on the electric working machine, and (ii) transmit the command to the input terminal via the output terminal.

12. The battery pack for an electric working machine according to claim 7, characterized in that: The battery pack for the electric working machine further includes an output terminal located on the first surface, wherein the output terminal is configured to (i) be connected to an input terminal of the electric working machine based on the mounting portion being mounted on the electric working machine, and (ii) transmit the command to the input terminal via the output terminal.

13. A method for suppressing discharge current in a battery pack for an electric working machine, characterized in that: The method includes: detecting a temperature of a fuse, wherein the fuse is located on a current path configured to allow the discharge current from a battery located in the battery pack to flow through the current path; and When the temperature satisfies a discharge suppression requirement, the discharge current is reduced or stopped, wherein the discharge suppression requirement is required in order to reduce or stop the discharge current.

14. The method for suppressing discharge current in a battery pack for an electric working machine according to claim 13, characterized in that: The method further includes: Assembling the fuse to the first surface of the substrate; and A temperature detector is mounted on a second surface of the substrate, wherein the temperature detector is configured to detect the temperature of the fuse, and the second surface is located on the opposite side of the first surface.

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