阅读说明：本技术 电动作业机以及电池组 (Electric working machine and battery pack ) 是由 市川佳孝 中本明弘 行田稔 加纳隼人 山田彻 铃木均 于 2019-09-12 设计创作，主要内容包括：本公开的一个方面是向电动作业机供给电力的电池组,具备：第一电池信号端子和第二电池信号端子。第一电池信号端子向电动作业机输出表示禁止放电或允许放电的第一信号。第二电池信号端子向电动作业机输出表示禁止放电或允许放电的第二信号。(One aspect of the present disclosure is a battery pack that supplies electric power to an electric working machine, including: a first battery signal terminal and a second battery signal terminal. The first battery signal terminal outputs a first signal indicating that discharge is prohibited or permitted to the electric working machine. The second battery signal terminal outputs a second signal indicating that discharge is prohibited or permitted to the electric working machine.)

1. A battery pack that supplies electric power to an electric working machine, the battery pack comprising:

a first battery signal terminal that outputs a first signal indicating that discharge is prohibited or permitted to the electric working machine; and

and a second battery signal terminal for outputting a second signal indicating that discharge is prohibited or permitted to the electric working machine.

2. The battery pack according to claim 1,

the first battery signal terminal is a dedicated terminal for outputting the first signal,

the second battery signal terminal is a serial communication terminal that outputs a plurality of battery signals including the second signal.

3. The battery pack according to claim 1 or 2,

the second signal includes: a third signal in accordance with the communication protocol and a fourth signal not in accordance with the communication protocol.

4. The battery pack according to claim 3,

the second battery signal terminal is configured to continuously output a voltage of a first level during standby, and to continuously output a voltage of a second level different from the first level as the fourth signal.

5. The battery pack according to claim 3 or 4,

the battery control unit is configured to transmit the third signal indicating that discharge is prohibited via the second battery signal terminal in response to the battery pack being in a state to be protected.

6. The battery pack according to claim 3 or 4,

the electric working machine includes: a motor; a drive switch for driving the motor; and a latch circuit configured to maintain a discharge inhibition state until the drive switch is turned off in response to a signal indicating that discharge is inhibited being input during an on period of the drive switch,

the first battery signal terminal or the second battery signal terminal is configured to be connected to the latch circuit,

the battery pack includes a battery control unit configured to transmit the signal indicating that discharge is prohibited, through a battery signal terminal not connected to the latch circuit, out of the first battery signal terminal and the second battery signal terminal, in response to the battery pack being in a state to be protected.

7. The assembled battery according to any one of claims 3 to 6, comprising:

a self-fusing fuse provided in the power output path;

a detection unit configured to detect a discharge current; and

and a battery control unit configured to blow the self-blow-out fuse when the detection unit detects the discharge current, even if the first signal indicating that discharge is inhibited is transmitted via the first battery signal terminal, and the third signal and the fourth signal indicating that discharge is electrically inhibited are transmitted via the second battery signal terminal.

8. The battery pack according to claim 3,

the frequency of serial communication via the second battery signal terminal is higher when current flows from the battery pack to the electric working machine than when current does not flow from the battery pack to the electric working machine.

9. The battery pack according to any one of claims 1 to 8,

the battery control unit is configured to transmit the first signal indicating that discharge is prohibited via the first battery signal terminal when the battery pack is in a state to be protected, and to transmit the second signal via the second battery signal terminal in response to a request from the electric working machine.

10. An electric working machine is provided with:

the battery pack according to any one of claims 1 to 9;

a motor configured to be rotated by receiving power supply from the battery pack;

a first signal terminal to which the first signal is input from the battery pack;

a second signal terminal to which the second signal is input from the battery pack; and

and a control unit configured to receive the first signal input to the first signal terminal and the second signal input to the second signal terminal, and to control driving of the motor using the received first signal and second signal.

11. The electric working machine according to claim 10,

the first signal terminal is a dedicated terminal to which the first signal is input,

the second signal terminal is a terminal to which a plurality of battery signals including the second signal are input.

12. The electric working machine according to claim 11,

the control unit is configured to transmit an information request signal requesting the battery signal via the second signal terminal, and receive the second signal input from the battery pack to the second signal terminal in response to the information request signal, and is configured to transmit the information request signal to the battery pack via the second signal terminal, and receive the second signal input from the battery pack to the second signal terminal in response to the information request signal, and the control unit is configured to transmit the

The first signal indicating that discharge is prohibited is received from the battery pack when the battery pack is in a state to be protected.

13. The electric working machine according to any one of claims 10 to 12,

the control unit receives the first signal indicating that discharge is prohibited via the first signal terminal when the first signal terminal is not connected to the battery pack.

14. The electric working machine according to any one of claims 10 to 13,

the second signal terminal is a serial communication terminal,

the control unit is configured to execute the same processing as that in the case where the second signal indicating that discharge is prohibited is received, when serial communication is not established between the electric working machine and the battery pack.

15. The electric working machine according to any one of claims 10 to 14,

the second signal terminal is a serial communication terminal,

the frequency of serial communication via the second signal terminal when current flows from the battery pack to the electric working machine is higher than when current does not flow from the battery pack to the electric working machine.

16. The electric working machine according to any one of claims 10 to 15,

the control unit is configured to:

stopping the driving of the motor in response to receiving a signal indicating that the discharging is prohibited via the first signal terminal or the second signal terminal at a first timing,

and a control unit configured to inhibit re-driving of the motor in response to a signal terminal, which does not receive the signal indicating inhibition of discharge at the first timing, of the first signal terminal and the second signal terminal not receiving the signal indicating inhibition of discharge for a period from the first timing to an elapse of a set time.

17. The electric working machine according to claim 16,

the predetermined release condition includes removing the battery pack from the electric working machine.

18. The electric working machine according to any one of claims 10 to 17, comprising:

a first connection path configured to connect the first signal terminal and the control unit; and

a second connection path configured to connect the second signal terminal and the control unit,

the first connection path and the second connection path are different paths independent of each other.

19. The electric working machine according to any one of claims 10 to 18,

the control unit is configured to allow discharge from the battery pack to the motor and drive the motor while receiving the first signal indicating permission of discharge and receiving the second signal indicating permission of discharge.

20. An electric working machine is provided with:

a battery pack;

a motor configured to be rotated by receiving power supply from the battery pack; and

a control unit configured to control driving of the motor,

the battery pack includes:

a first battery signal terminal configured to output a first signal indicating that discharge is prohibited or permitted; and

a second battery signal terminal configured to output a second signal indicating that discharge is prohibited or permitted,

the control unit includes:

a first signal terminal configured to be connected to the first battery signal terminal; and

a second signal terminal configured to be connected to the second battery signal terminal,

the control unit is configured to control driving of the motor using the first signal received via the first signal terminal and the second signal received via the second signal terminal.

21. The electric working machine according to claim 20,

the first signal comprises a signal not in accordance with a communication protocol,

the second signal comprises a signal according to a communication protocol.

22. The electric working machine according to claim 20 or 21,

the first battery signal terminal is a dedicated terminal for transmitting a signal from the battery pack to the control unit,

the second battery signal terminal is a serial communication terminal for enabling transmission and reception of signals between the battery pack and the control unit.

23. The electric working machine according to any one of claims 20 to 22,

the battery pack includes a battery control unit configured to transmit at least one of the first signal and the second signal indicating that discharge is prohibited in response to the battery pack being in a state to be protected,

the battery control unit is configured to transmit the second signal indicating that discharge is prohibited by serial communication via the second battery signal terminal in response to the battery control unit being in the state to be protected.

24. The electric working machine according to any one of claims 20 to 22,

further comprises a drive switch for driving the motor,

the control unit includes a latch circuit connected to the first signal terminal or the second signal terminal, and configured to maintain a discharge inhibition state until the drive switch is turned off in response to a signal indicating that discharge is inhibited being input during an on period of the drive switch,

the battery pack is configured to transmit the signal indicating that discharge is prohibited via a battery signal terminal, and the battery signal terminal is one of the first battery signal terminal and the second battery signal terminal that is not connected to the latch circuit via the first signal terminal or the second signal terminal.

25. The electric working machine according to any one of claims 20 to 24,

the second signal includes: a third signal in accordance with the communication protocol and a fourth signal not in accordance with the communication protocol,

the first battery signal terminal is configured to continuously output a voltage of a first level as the first signal during standby,

the second battery signal terminal is configured to output a serial communication signal as the third signal, continuously output a voltage of a second level during standby, and continuously output a voltage of a third level different from the second level as the fourth signal.

Technical Field

The present disclosure relates to an electric working machine and a battery pack.

Background

The electric power tool described in patent document 1 includes: an input terminal pair that receives power supply from the battery pack; and a signal input terminal to which a discharge stop instruction signal output from the battery pack is input. In the electric power tool, the switching element for controlling the current of the motor is driven when the discharge stop command signal is not input to the signal input terminal, and the switching element is stopped to protect the battery pack when the discharge stop command signal is input to the signal input terminal.

Patent document 1: japanese patent laid-open publication No. 2005-131770

In the communication between the battery pack and the electric power tool, there is a possibility that a failure in which the discharge stop command signal output from the battery pack is not input to the signal input terminal, that is, a failure in which the input state of the signal input terminal indicates a discharge permitted state, occurs. When such a failure occurs in the electric power tool, the battery pack may be allowed to discharge when it is to be protected, and the battery pack may be deteriorated.

Disclosure of Invention

The present disclosure provides a battery pack and an electric working machine capable of suppressing deterioration of the battery pack.

One aspect of the present disclosure is a battery pack that supplies electric power to an electric working machine, including: a first battery signal terminal and a second battery signal terminal. The first battery signal terminal outputs a first signal indicating that discharge is prohibited or permitted to the electric working machine. The second battery signal terminal outputs a second signal indicating that discharge is prohibited or permitted to the electric working machine.

The battery pack includes: a first battery signal terminal outputting a first signal and a second battery signal terminal outputting a second signal. Therefore, even in the event of a failure in which one of the first signal and the second signal indicating that discharge is inhibited is received by the electric working machine as a signal indicating that discharge is permitted, the electric working machine can receive the other signal indicating that discharge is inhibited. Therefore, the battery pack can be appropriately protected against deterioration.

The first battery signal terminal may be a dedicated terminal that outputs the first signal. The second battery signal terminal may be a serial communication terminal that outputs a plurality of battery signals including the second signal.

The battery pack can output a second signal using a second battery signal terminal that outputs other battery signals. Thus, the battery pack can output the first signal and the second signal without increasing the number of terminals, and is protected appropriately.

The second signal may also comprise: a third signal in accordance with the communication protocol and a fourth signal not in accordance with the communication protocol.

By the second signal including the signal conforming to the communication protocol and the signal not conforming to the communication protocol, it is possible to transmit the inhibition of discharge from the battery pack to the electric working machine by a total of three kinds of signals. Therefore, the battery pack can be appropriately protected against deterioration.

The second battery signal terminal may be configured to continuously output a voltage of a first level during standby and continuously output a voltage of a second level different from the first level as the fourth signal.

The noise resistance of a signal with a constant voltage level is higher than that of a signal with a varying voltage level. Here, in the overload state, there is a tendency that the signal output from the battery pack easily overlaps with noise. Thus, by using a signal having a constant voltage level as a signal that does not comply with the communication protocol, it is possible to improve the reliability with which the electric working machine receives a signal indicating that discharge is prohibited when the battery pack needs to be protected.

The battery control unit may be configured to transmit a third signal indicating that discharge is prohibited via the second battery signal terminal in response to the battery pack being in a state to be protected.

In response to the battery pack becoming a state to be protected, a signal in accordance with the communication protocol is first transmitted. Thus, the electric working machine can recognize the state of the battery pack before stopping the discharge, and perform processing according to the states of the battery pack and the electric working machine.

The electric working machine may further include: a motor; a drive switch for driving the motor; and a latch circuit configured to maintain the discharge inhibition state until the drive switch is turned off in response to a signal indicating that the discharge is inhibited being input during the drive switch on period. The first battery signal terminal or the second battery signal terminal may be connected to the latch circuit. The battery pack may include a battery control unit configured to transmit a signal indicating that discharge is prohibited, via a battery signal terminal not connected to the latch circuit, out of the first battery signal terminal and the second battery signal terminal, in response to the battery pack being in a state to be protected.

Preferably, even if an abnormality occurs in the battery control unit and the signal indicating that discharge is prohibited disappears when protecting the battery pack, sudden operation of the electric working machine (specifically, sudden operation of the motor of the electric working machine) can be avoided. Therefore, the electric working machine may be provided with a latch circuit. However, once the latch circuit operates, the latch circuit is troublesome to release. Therefore, in response to the battery pack being in a state to be protected, a signal indicating that discharge is prohibited is first transmitted via the battery signal terminal not connected to the latch circuit. This makes it possible to prevent sudden operation of the electric working machine while suppressing the processing load on the battery pack and the electric working machine associated with the release of the latch circuit.

The battery pack may include a self-fusing fuse, a detection unit, and a battery control unit. The self-blowing fuse is provided in an output path of power. The detection unit is configured to detect a charge/discharge current. The battery control unit is configured to blow the self-blow fuse when the detection unit detects a discharge current, even when a first signal indicating that discharge is inhibited is transmitted via the first battery signal terminal, and a third signal and a fourth signal indicating that discharge is electrically inhibited are transmitted via the second battery signal terminal.

When a discharge current flows even when three types of signals indicating that discharge is inhibited are transmitted to the electric working machine, the self-blowing fuse is blown. Thus, when the discharge cannot be stopped in a state where the battery pack can be used, the battery pack can be set to a non-usable state, and the safety of the battery pack can be ensured.

The battery control unit may be configured to transmit a first signal indicating that discharge is prohibited via the first battery signal terminal when the battery pack is in a state to be protected, and to transmit a second signal via the second battery signal terminal in response to a request from the electric working machine.

The frequency of serial communication via the second signal terminal may be higher when current flows from the battery pack to the electric working machine than when current does not flow from the battery pack to the electric working machine.

When no current flows from the battery pack to the electric working machine, the state of the battery pack is less likely to change than when a current flows from the battery pack to the electric working machine. Thus, when no current flows from the battery pack to the electric working machine, the frequency of serial communication can be suppressed lower than when a current flows from the battery pack to the electric working machine. This can suppress the processing load and current consumption of the electric working machine and the battery pack.

The battery control unit can transmit a first signal indicating that discharge is prohibited in real time when the battery pack is in a state to be protected. In response to a request from the electric working machine, the battery control unit can transmit a second signal based on the state of the battery pack when the request is received. Thus, when the battery pack is in a state to be protected upon receiving a request from the electric working machine, the battery control unit can transmit a second signal indicating that discharge is prohibited via the second battery signal terminal.

An electric working machine according to another aspect of the present disclosure includes: the battery pack, the motor, the first signal terminal, the second signal terminal and the control unit are provided. The motor is configured to be rotated by receiving power supply from the battery pack. The first signal terminal is inputted with a first signal. The second signal terminal is inputted with a second signal. The control unit is configured to receive a first signal input to the first signal terminal and a second signal input to the second signal terminal, and control driving of the motor using the received first signal and second signal.

When a failure occurs in which a signal indicating that discharge is permitted is received via one of the first signal terminal and the second signal terminal despite the input of a signal indicating that discharge is prohibited from the battery pack, the control unit of the electric working machine can receive a signal indicating that discharge is prohibited via the other signal terminal. This can appropriately protect the battery pack and suppress deterioration of the battery pack.

The first signal terminal may be a dedicated terminal to which the first signal is input. The second signal terminal may be a terminal to which a plurality of battery signals including the second signal are input.

A second signal is input to a second signal terminal to which a battery signal other than a signal indicating permission or inhibition of discharge is input. Thus, the control unit can receive the first signal and the second signal and protect the battery pack in multiple ways without increasing the number of terminals of the electric working machine.

The control section may also transmit an information request signal requesting a battery signal via the second signal terminal, and receive a second signal input from the battery pack to the second signal terminal in response to the information request signal. The control unit may receive a first signal indicating that discharge is prohibited, the first signal being input from the battery pack to the first signal terminal when the battery pack is in a state to be protected.

The control unit can receive a first signal indicating that discharge is prohibited in real time when the battery pack is in a state to be protected. In addition, the control unit can receive a second signal based on the state of the battery pack in response to the information request signal transmitted by the control unit. Thus, when the battery pack is in a state to be protected when receiving the information request signal, the control unit can receive a signal indicating that discharge is prohibited via the second signal terminal.

The control unit may receive a first signal indicating that discharge is prohibited via the first signal terminal when the first signal terminal is not connected to the battery pack.

When the first signal terminal is not connected to the battery pack, the control unit receives a first signal indicating that discharge is prohibited, and the battery pack can be protected from discharge by prohibiting the discharge.

The second signal terminal may also be a serial communication terminal. When the serial communication is not established between the electric working machine and the battery pack, the control unit may execute the same processing as that in the case where the second signal indicating that the discharge is prohibited is received.

Since the second signal terminal is a serial communication terminal, the electric working machine can receive a plurality of battery signals by the second signal terminal. Further, in a case where serial communication is not established between the electric working machine and the battery pack, the electric working machine executes the same processing as in a case where the second signal indicating that discharge is prohibited is received. Thus, the electric working machine can inhibit the discharge protection of the battery pack when serial communication is not established between the electric working machine and the battery pack.

The second signal terminal may also be a serial communication terminal. The frequency of serial communication via the second signal terminal may be higher when current flows from the battery pack to the electric working machine than when current does not flow from the battery pack to the electric working machine.

When no current flows from the battery pack to the electric working machine, the state of the battery pack is less likely to change than when a current flows from the battery pack to the electric working machine. Thus, when no current flows from the battery pack to the electric working machine, the frequency of serial communication can be suppressed lower than when a current flows from the battery pack to the electric working machine. This can suppress the processing load and current consumption of the electric working machine and the battery pack.

The control unit may stop the driving of the motor in response to receiving a signal indicating that the discharging is prohibited via the first signal terminal or the second signal terminal at the first timing. Further, the control unit may prohibit the re-driving of the motor unless a predetermined cancel condition is established in response to the signal terminal, which does not receive the signal indicating the prohibition of the discharge at the first timing, of the first signal terminal and the second signal terminal continuing to receive the signal indicating the prohibition of the discharge from the first timing until the set time elapses.

In the case where the signal indicating that the discharge is inhibited is not received via the other signal terminal although the signal indicating that the discharge is inhibited is received via one of the two signal terminals by the control section, there is a possibility that an abnormality occurs. Thus, in this case, the control unit prohibits the re-driving of the motor unless the predetermined cancel condition is established. This can appropriately protect the battery pack.

The predetermined release condition may include removing the battery pack from the electric working machine.

In this case, the prohibition of the re-driving of the motor can be released by removing the battery pack from the electric working machine.

The electric working machine may further include: a first connection path, and a second connection path. The first connection path is configured to connect the first signal terminal and the control unit. The second connection path is configured to connect the second signal terminal and the control unit. The first signal path and the second connection path may be different paths independent of each other.

Since the first connection path and the second connection path are independent paths, the battery pack can be protected more appropriately and multiply.

The control unit may allow discharge from the battery pack to the motor to drive the motor while receiving the first signal indicating permission of discharge and receiving the second signal indicating permission of discharge.

The control unit permits discharge from the battery pack to the motor only when both the first and second signals indicate permission of discharge. Therefore, when a failure occurs in which the control unit receives a signal indicating that discharge is permitted via one of the two signal terminals despite the signal indicating that discharge is prohibited being transmitted from the battery pack, the control unit can prohibit discharge from the battery pack to the motor, thereby protecting the battery pack.

Another aspect of the present disclosure is an electric working machine including: battery pack, motor and control unit. The motor is configured to be rotated by receiving power supply from the battery pack. The control unit is configured to control driving of the motor. The battery pack includes: a first battery signal terminal and a second battery signal terminal. The first battery signal terminal is configured to output a first signal indicating that discharge is prohibited or permitted. The second battery signal terminal is configured to output a second signal indicating that discharge is prohibited or permitted. The control unit includes: a first signal terminal and a second signal terminal. The first signal terminal is configured to be connected to a first battery signal terminal. The second signal terminal is configured to be connected to a second battery signal terminal. The control unit is configured to control driving of the motor using a first signal received via the first signal terminal and a second signal received via the second signal terminal.

The first signal and the second signal are transmitted from the battery pack to a control unit of the electric working machine via different battery signal terminals. That is, the battery pack includes a plurality of cells that transmit a signal indicating that discharge is prohibited to the control unit. This can protect the battery pack more appropriately and suppress deterioration of the battery pack.

The first signal may also comprise a signal that is not in accordance with a communication protocol. The second signal may also comprise a signal in accordance with a communication protocol.

The signal not complying with the communication protocol and the signal complying with the communication protocol can be transmitted from the battery pack to the control section via different battery signal terminals.

The first battery signal terminal may be a dedicated terminal for transmitting a signal from the battery pack to the control unit. The second battery signal terminal may be a serial communication terminal for transmitting and receiving signals between the battery pack and the control unit.

The second signal is transmitted from the battery pack to the control unit using a serial communication terminal provided for serial communication between the battery pack and the control unit. This makes it possible to protect the battery pack in multiple ways without increasing the number of terminals of the electric working machine and the battery pack.

The battery pack may include a battery control unit configured to transmit at least one of a first signal and a second signal indicating that discharge is prohibited in response to the battery pack being in a state to be protected. In response to the state to be protected, the battery control unit may be configured to first transmit a second signal indicating that discharge is prohibited by serial communication via the second battery signal terminal.

In response to the battery pack becoming a state to be protected, a signal in accordance with the communication protocol is first transmitted. Thus, the electric working machine can recognize the state of the battery pack before stopping the discharge, and perform processing according to the states of the battery pack and the electric working machine.

The electric working machine may further include a drive switch for driving the motor. The control unit may include a latch circuit connected to the first signal terminal or the second signal terminal, and configured to maintain the discharge inhibition state until the drive switch is turned off in response to an input of a signal indicating inhibition of discharge during an on period of the drive switch. The battery pack may be configured to transmit a signal indicating that discharge is prohibited via a battery signal terminal that is not connected to the latch circuit via the first signal terminal or the second signal terminal, of the first battery signal terminal and the second battery signal terminal.

In response to the battery pack being in a state to be protected, a signal indicating that discharge is prohibited is first transmitted via a battery signal terminal not connected to the latch circuit. This makes it possible to prevent sudden operation of the electric working machine while suppressing the processing load on the battery pack and the electric working machine associated with the release of the latch circuit.

The second signal may also comprise: a third signal in accordance with the communication protocol and a fourth signal not in accordance with the communication protocol. The first battery signal terminal may be configured to continuously output a voltage of a first level as the first signal. The second battery signal terminal may be configured to output the serial communication signal as a third signal, and to continuously output a voltage of a second level during standby, and to continuously output a voltage of a third level different from the second level as a fourth signal.

A fourth signal having high noise resistance is transmitted from the battery pack to the control unit via the second battery signal terminal in addition to the third signal which is a serial signal. This makes it possible to protect the battery pack more appropriately without increasing the number of terminals of the electric working machine and the battery.

The present disclosure also includes the following items.

[ item A1]

The electric working machine includes: the motor, first communication terminal, second communication terminal and control unit. The motor is configured to be rotated by receiving power supply from the battery pack. The first communication terminal inputs first discharge information indicating whether discharge of the battery pack is prohibited or permitted from the battery pack. The second communication terminal inputs second discharge information indicating whether discharge of the battery pack is prohibited or permitted from the battery pack. The control unit is configured to receive first discharge information input to the first communication terminal and second discharge information input to the second communication terminal, and control driving of the motor using the received first discharge information and second discharge information.

The electric working machine includes a first communication terminal and a second communication terminal, and the first communication terminal and the second communication terminal receive discharge information from the battery pack. Therefore, when a failure occurs in which the discharge information indicating that the discharge is permitted is received via any one of the first communication terminal and the second communication terminal although the discharge information indicating that the discharge is prohibited is input from the battery pack, the control unit can receive the discharge information indicating that the discharge is prohibited via the other communication terminal. This can appropriately protect the battery pack and suppress deterioration of the battery pack.

[ item A2]

The first communication terminal may be a dedicated terminal to which the first discharge information is input. The second communication terminal may be a terminal to which a plurality of pieces of battery information including the second discharge information are input.

The second discharge information is input to a second communication terminal to which the battery information other than the discharge information is input. Thus, the control unit can receive the first and second discharge information and protect the battery pack doubly without increasing the number of terminals of the electric working machine.

[ item A3]

In addition, the control portion may also transmit an information request signal requesting battery information via the second communication terminal, and receive second discharge information input from the battery pack to the second communication terminal in response to the information request signal. The control unit may receive first discharge information indicating that discharge is prohibited, the first discharge information being input from the battery pack to the first communication terminal when the battery pack is in a state to be protected.

The control unit can receive first discharge information indicating that discharge is prohibited in real time when the battery pack is in a state to be protected. In addition, the control unit can receive second discharge information based on the state of the battery pack in response to the information request signal transmitted by the control unit. Thus, when the battery pack is in a state to be protected when receiving the information request signal, the control unit can receive battery information indicating that discharge is prohibited, using the second communication terminal.

[ item A4]

In addition, the control unit may receive first discharge information indicating that discharge is prohibited via the first communication terminal when the first communication terminal is not connected to the battery pack.

When the first communication terminal is not connected to the battery pack, the control unit can inhibit the discharge protection of the battery pack by receiving first discharge information indicating that discharge is inhibited.

[ item A5]

The second communication terminal may be a serial communication terminal. The control unit may execute the same processing as in the case where the second communication terminal receives the second discharge information indicating that the discharge is prohibited, when the serial communication is not established between the electric working machine and the battery pack.

Since the second communication terminal is a serial communication terminal, the electric working machine can receive the plurality of battery information by the second communication terminal. Further, in a case where serial communication is not established between the electric working machine and the battery pack, the electric working machine executes the same processing as in a case where the second discharge information indicating that discharge is prohibited is received. Thus, the electric working machine can inhibit the discharge protection of the battery pack when serial communication is not established between the electric working machine and the battery pack.

[ item A6]

When the second communication terminal is a serial communication terminal, the frequency of serial communication via the second communication terminal may be higher when current flows from the battery pack to the electric working machine than when current does not flow from the battery pack to the electric working machine.

When no current flows from the battery pack to the electric working machine, the state of the battery pack is less likely to change than when a current flows from the battery pack to the electric working machine. Thus, when no current flows from the battery pack to the electric working machine, the frequency of serial communication can be suppressed lower than when a current flows from the battery pack to the electric working machine. This can suppress the processing load and current consumption of the electric working machine and the battery pack.

[ item A7]

The electric working machine may further include an operation unit that is operated to instruct driving of the motor. The control unit may stop the driving of the motor when the discharge information indicating that the discharge is prohibited is received via one of the first communication terminal and the second communication terminal, and prohibit the re-driving of the motor unless a predetermined cancellation condition is established when the discharge information indicating that the discharge is prohibited is not received via the other of the first communication terminal and the second communication terminal within a set time after the discharge information indicating that the discharge is prohibited is received via the one communication terminal.

In the case where the discharge information indicating that the discharge is inhibited is not received through the other communication terminal although the discharge information indicating that the discharge is inhibited is received through one of the two communication terminals by the control portion, there is a possibility that an abnormality occurs. Therefore, in this case, the control unit prohibits the re-driving of the motor unless the predetermined cancel condition is established. This can protect the battery pack.

[ item A8]

The predetermined release condition may include removing the battery pack from the electric working machine.

In this case, the inhibition of the re-driving of the motor can be cancelled by removing the battery pack from the electric working machine.

[ item A9]

Further, the electric working machine may include: a first connection path and a second connection path. The first connection path connects the first communication terminal and the control unit. The second connection path connects the second communication terminal and the control unit. The first connection path and the second connection path may be different paths independent of each other.

Since the first connection path and the second connection path are independent paths, the battery pack can be protected more appropriately doubly.

[ item A10]

The control unit may allow the discharge from the battery pack to the motor to drive the motor while the first communication terminal receives the first discharge information indicating that the discharge is allowed and the second communication terminal receives the second discharge information indicating that the discharge is allowed.

The control unit permits discharge from the battery pack to the motor only when both the first and second discharge information indicate permission of discharge. Therefore, when a failure occurs in which the discharge information indicating that the discharge is prohibited is received via one of the two communication terminals despite the discharge information indicating that the discharge is prohibited being transmitted from the battery pack, the control unit can prohibit the discharge from the battery pack to the motor and protect the battery pack.

[ item B1]

An assembled battery for supplying electric power to an electric working machine, comprising: a first battery communication terminal and a second battery communication terminal. The first battery communication terminal outputs first discharge information indicating whether to prohibit or permit discharge to the electric working machine. The second battery communication terminal outputs second discharge information indicating whether to prohibit or permit discharge to the electric working machine.

The battery pack includes: a first battery communication terminal outputting first discharge information; and a second battery communication terminal outputting second discharge information. Therefore, even when a failure occurs in which one of the first and second discharge information indicating that discharge is prohibited is received by the electric working machine as discharge information indicating that discharge is permitted, the other discharge information indicating that discharge is prohibited can be received by the electric working machine. Therefore, the battery pack can be appropriately protected against deterioration.

[ item B2]

The first battery communication terminal may be a dedicated terminal for outputting the first discharge information. The second battery communication terminal may be a terminal that outputs a plurality of pieces of battery information including the second discharge information.

The battery pack is capable of outputting second discharge information using a second battery communication terminal that outputs other battery information. Thus, the battery pack can output the first and second discharge information and be appropriately protected without increasing the number of terminals.

[ item B3]

The battery pack may further include a battery control unit configured to transmit first discharge information indicating that discharge is prohibited via the first battery communication terminal when the battery pack is in a state to be protected, and to transmit second discharge information via the second battery communication terminal in response to a request from the electric working machine.

The battery control unit can transmit first discharge information indicating that discharge is prohibited in real time when the battery pack is in a state to be protected. In response to a request from the electric working machine, the battery control unit can transmit second discharge information based on the state of the battery pack when the request is received. Thus, when the battery pack is in a state to be protected upon receiving a request from the electric working machine, the battery control unit can transmit second discharge information indicating that discharge is prohibited via the second battery communication terminal.

Drawings

Fig. 1 is a perspective view showing an external appearance of a work machine system according to a first embodiment.

Fig. 2 is a block diagram showing a configuration of a motor control system according to the first embodiment.

Fig. 3 is a flowchart showing a discharge control process executed by the battery control circuit of the first embodiment.

Fig. 4 is a flowchart showing a main process executed by the control circuit of the working machine according to the first embodiment.

Fig. 5 is a flowchart showing a battery state identification process executed by the control circuit of the working machine according to the first embodiment.

Fig. 6 is a flowchart showing a discharge setting process executed by the control circuit of the working machine according to the first embodiment.

Fig. 7 is a flowchart showing discharge abnormality processing executed by the control circuit of the working machine according to the first embodiment.

Fig. 8 is a flowchart showing a motor driving process executed by the control circuit of the working machine according to the first embodiment.

Fig. 9 is a block diagram showing a configuration of a motor control system according to a second embodiment.

Fig. 10 is a flowchart showing a procedure of the discharge control processing of the second embodiment.

Fig. 11 is an explanatory diagram showing the output process of three discharge prohibition signals according to the second embodiment.

Fig. 12 is a flowchart showing a procedure of the discharge control processing of the third embodiment.

Fig. 13 is an explanatory diagram showing the output process of three discharge prohibition signals according to the third embodiment.

Fig. 14 is a flowchart showing a procedure of the discharge control processing of the fourth embodiment.

Fig. 15 is an explanatory diagram showing the output process of three types of discharge prohibition signals according to the fourth embodiment.

Description of reference numerals: 1 … working machine, 2 … main pipe, 3 … control unit, 4 … driving unit, 5 … cover, 5V … dc, 6 … handle, 7 … right handle, 8 … left handle, 9 … positive and negative change-over switch, 10 … locking button, 11 … trigger, 12 … trigger, 13 … control wiring pipe, 16 … motor housing, 17 … cutting knife, 21 … rear end housing, 22 … battery pack, 23 … gear shift disc, 24 … main switch, 25 … display, 28 … battery voltage detection unit, 30 … controller, 32 … driving circuit, 34 … gate circuit, 35 … latch circuit, 36 … control circuit, 38 … regulator, 39 … stop circuit, 41 … positive terminal, 42 … terminal, 43 … DS terminal, 44 … serial terminal, 3648 first connection wire, … control circuit, 50 motor …, … detection unit, … temperature detection unit, … detection …, 60 … battery, 61 … battery positive terminal, 62 … battery negative terminal, 63 … battery DS terminal, 64 … battery serial terminal, 65 … battery control circuit, 66 … with self-fusing type control fuse, 67 … shunt resistor, 68 … first battery connection line, 69 … second battery connection line.

Detailed Description

(first embodiment)

Hereinafter, a mode for carrying out the present disclosure will be described with reference to the drawings.

< 1. integral Structure >

As shown in fig. 1, in the present exemplary embodiment, a case where the electric working machine of the present disclosure is applied to a weeding machine will be described. The work machine system of the present exemplary embodiment includes work machine 1 and battery pack 22. The working machine 1 is a weeding machine including a main pipe 2, a control unit 3, a drive unit 4, a cover 5, and a handle 6. The main pipe 2 is formed in an elongated and hollow rod shape. The control unit 3 is provided on the rear end side of the main pipe 2. The drive unit 4 and the cover 5 are provided on the distal end side of the main pipe 2.

The drive unit 4 includes: a motor housing 16 and a cutter 17. The cutting blade 17 is a disk-shaped blade for collecting objects to be cut such as cut grass and small diameter trees, and is configured to be attachable to and detachable from the motor housing 16. The cover 5 is provided to suppress grass or the like harvested by the cutter blades 17 from flying toward a user of the working machine 1.

A motor 50 is mounted inside the motor housing 16, and the motor 50 generates a rotational force for rotating the cutting blade 17. The rotational force generated by the driving of the motor 50 is transmitted to the rotating shaft to which the cutting blade 17 is attached via the speed reduction mechanism. When the cutter blade 17 is rotated by the rotational force of the motor 50, the user can cut the object by bringing the outer peripheral portion of the cutter blade 17 into contact with the object.

The handle 6 is formed in a U-shape and connected to the main pipe 2 near an intermediate position in the longitudinal direction of the main pipe 2. A right grip 7 to be held by a user with a right hand is provided on a first end side of the handle 6, and a left grip 8 to be held by a user with a left hand is provided on a second end side of the handle 6.

A forward/reverse selector switch 9, a lock button 10, and a trigger 11 are provided on the front end side of the right grip 7. The forward/reverse switch 9 switches the rotation direction of the motor 50, that is, the rotation direction of the blade 17, to either forward or reverse. The normal rotation is a rotation direction set when grass or the like is harvested, and the reverse rotation is a rotation direction set when grass or the like wound around the cutter 17 is removed.

The trigger 11 is an operation member that is operated by the user to instruct the rotation or stop of the cutting blade 17. A trigger switch 12 that operates in conjunction with the trigger 11 is disposed inside the right handle 7. The trigger switch 12 is turned on when the trigger 11 is operated, and turned off when the trigger 11 is not operated, and outputs a trigger signal TS indicating the on state or the off state. In the present embodiment, the trigger switch 12 corresponds to an example of a drive switch.

The lock button 10 is a button for preventing or suppressing malfunction of the cutter 17. In a state where the lock button 10 is not pressed, the lock button 10 is mechanically engaged with the trigger 11. This restricts the operation of the trigger 11, and prevents or suppresses the trigger switch 12 from being turned on. When the lock button 10 is pressed, the engagement of the lock button 10 with the trigger 11 is released.

A control wiring duct 13 is provided between the lower end of the right grip 7 and the front end of the control unit 3. The control wiring duct 13 is formed in a hollow rod shape, and a control harness is disposed inside the control wiring duct. The control harness is a wiring for electrically connecting the trigger switch 12 and the forward/reverse changeover switch 9 to the control unit 3.

The control unit 3 includes: a rear end case 21 and a battery pack 22.

A shift dial 23 and a main switch 24 are provided on the front end side of the rear housing 21 in a user-operable state. The shift disk 23 is provided for a user to variably set the rotation speed of the motor 50. The main switch 24 is a switch for starting the power supply from the battery 60 to each unit, thereby allowing the work machine 1 to be in a usable state. When the main switch 24 is turned on, a discharge path from the battery 60 to the motor 50 is formed, and when the main switch 24 is turned off, the discharge path from the battery 60 to the motor 50 is cut off.

Further, a display portion 25 is provided on the front end side of the rear end housing 21 so that a user can visually confirm. The display unit 25 is provided to notify the user of an operation state, abnormality, or the like, and includes a display lamp, a remaining amount display lamp, a reverse display lamp, and the like. The indicator lamp is turned on when the main switch 24 is turned on to supply power to each part of the work machine 1. The remaining amount display lamp displays the remaining amount of the battery 60. The reverse indicator light indicates that the motor 50 is rotating in the reverse direction. Further, the remaining amount is the amount of electricity remaining in the battery 60.

A controller 30 described later is disposed inside the rear end housing 21. The controller 30 mainly performs control of the motor 50. The controller 30 controls the driving of the motor 50 by controlling the energization to the motor 50.

The battery pack 22 is detachably attached to the rear end of the rear case 21.

As shown in fig. 2, the battery pack 22 includes: battery 60, battery control circuit 65, battery positive terminal 61, battery negative terminal 62, battery DS terminal 63, and battery TR terminal 64. The battery 60 is configured by connecting a plurality of battery cells in series. The battery 60 is a rechargeable power supply for supplying electric power to each part in the rear case 21 and the motor 50. As an example, the battery 60 includes a lithium ion secondary battery. The rated voltage of the battery 60 may be 64V, for example.

< 2. Structure of Motor control System >

Next, the configuration of the control system 100 of the motor 50 including the battery control circuit 65 and the controller 30 will be described with reference to fig. 2.

The battery control circuit 65 includes: the CPU65a, ROM65b, RAM65c, I/O, and the like execute error stop signal control processing and the like described later.

The battery positive terminal 61 is connected to the positive side of the battery 60. The battery negative terminal 62 is connected to the negative side of the battery 60. The battery DS terminal 63 is connected to the battery control circuit 65 via a first battery connection line 68. The battery DS terminal 63 is a dedicated terminal for transmitting a first signal from the battery pack 22. The first signal is a signal that is not in accordance with a communication protocol. DS is an abbreviation for discharge stop.

Battery TR terminal 64 is connected to battery control circuit 65 via second battery connection line 69. Battery TR terminal 64 is a serial communication terminal for transmitting a plurality of battery signals by serial communication. TR is an abbreviation of transmission/reception. The plurality of battery signals includes a second signal according to a communication protocol.

The first battery connection line 68 and the second battery connection line 69 are mutually independent and different connection lines that do not include a common portion. The first signal and the second signal are signals indicating whether to prohibit or permit discharge from the battery 60. In the present embodiment, the battery control circuit 65 corresponds to an example of a battery control unit, the battery DS terminal 63 corresponds to an example of a first battery signal terminal, and the battery TR terminal 64 corresponds to an example of a second battery signal terminal.

The battery pack 22 further includes: a cell voltage detection unit, a cell temperature detection unit, and a battery current detection unit, which are not shown. The cell voltage detection unit detects the voltage value of each cell of the battery 60 and outputs a detection signal to the battery control circuit 65. The cell temperature detecting unit is composed of a thermistor or the like, detects the temperature of at least one cell, and outputs a detection signal to the battery control circuit 65. The battery current detection unit detects a charge/discharge current of the battery 60 and outputs a detection signal to the battery control circuit 65.

The controller 30 includes: a positive terminal 41, a negative terminal 42, a DS terminal 43, and a TR terminal 44. The controller 30 further includes: drive circuit 32, gate 34, control circuit 36, and regulator 38.

The positive terminal 41 is connected to a battery positive terminal 61 of the battery pack 22. The negative terminal 42 is connected to a battery negative terminal 62 of the battery pack 22. The DS terminal 43 is a terminal connected to the battery DS terminal 63 of the battery pack 22, and is a dedicated terminal for receiving the first signal transmitted from the battery pack 22. The TR terminal 44 is a terminal for receiving a plurality of battery signals including the second signal transmitted from the battery pack 22 by serial communication.

The DS terminal 43 is connected to the control circuit 36 via a first connection line 48, and the TR terminal 44 is connected to the control circuit 36 via a second connection line 49. The first connection line 48 and the second connection line 49 are mutually independent different connection lines including no common portion. That is, the DS connection path and the serial connection path are mutually independent and different paths including no common portion. The DS connection path includes the first battery connection line 68 and the first connection line 48, and connects the battery control circuit 65 and the control circuit 36 via the battery DS terminal 63 and the DS terminal 43. The serial connection path includes a second battery connection line 69 and a second connection line 49, and connects the battery control circuit 65 and the control circuit 36 via the battery TR terminals 64 and 44.

The drive circuit 32 is a circuit that receives power supply from the battery 60 and causes current to flow through each winding corresponding to each motor 50. The motor 50 is a three-phase brushless motor. The drive circuit 32 is a three-phase full bridge circuit, and includes: high-side switching devices Q1 to Q3, and low-side switching devices Q4 to Q6. Each of the switching elements Q1 to Q6 includes, for example, a MOSFET, but may include a structure other than a MOSFET.

The gate circuit 34 turns on or off the switching elements Q1 to Q6 in accordance with a control signal output from the control circuit 36, and causes currents to flow through the phase windings of the motor 50 in sequence, thereby rotating the motor 50. When all of the switching elements Q1 to Q6 are turned off, the motor 50 is in an idling state. When the switching elements Q1 to Q3 are all turned off and the switching elements Q4 to Q6 are all turned on, the motor 50 is in a state where so-called short brake is applied.

The regulator 38 receives power supply from the battery 60 while the battery pack 22 is connected to the work machine 1, and generates a constant power supply voltage Vcc (for example, dc 5V) necessary for operating the control circuit 36.

The control circuit 36 includes: CPU36a, ROM36b, RAM36c, and I/O, among others. The control circuit 36 is connected to the DS terminal 43, the TR terminal 44, the trigger switch 12, the main switch 24, the display unit 25, and the battery voltage detection unit 28. Although not shown, the control circuit 36 is also connected to the forward/reverse selector switch 9 and the shift dial 23.

The battery voltage detection unit 28 detects a voltage between the positive terminal 41 and the negative terminal 42, that is, a value of a voltage of the battery 60 (hereinafter, referred to as a battery voltage), and outputs a detection signal to the control circuit 36.

In the controller 30, a current detection unit 54 is provided in a current path from the drive circuit 32 to the negative electrode of the battery 60, and the current detection unit 54 detects the value of the current flowing through the motor 50. Further, a rotation sensor 52 is provided in the vicinity of the motor 50, and the rotation sensor 52 detects the rotational position of the rotor included in the motor 50. The rotation sensor 52 is, for example, an optical encoder, a magnetic encoder, or the like. A temperature detector 56 is provided in the vicinity of the switching element of the drive circuit 32, and the temperature detector 56 is constituted by a thermistor or the like that detects the temperature of the switching element. Detection signals from the current detection unit 54, the rotation sensor 52, and the temperature detection unit 56 are also input to the control circuit 36.

The control circuit 36 operates by receiving power supply from the regulator 38. The control circuit 36 executes various processes including a main process described later based on various detection signals and operation states of various switches. In the present embodiment, the controller 30 corresponds to an example of a control unit, the DS terminal 43 corresponds to an example of a first signal terminal, and the TR terminal 44 corresponds to an example of a second signal terminal.

< 3. processing in Battery pack >

< 3-1. discharge control processing >

Next, a discharge control process executed by the battery control circuit 65 will be described with reference to the flowchart of fig. 3. When the battery control circuit 65 detects the connection of the electric working machine, the present process is started.

First, in S10, the battery control circuit 65 outputs a discharge permission signal indicating permission of discharge from the battery DS terminal 63 as a first signal.

Next, in S20, battery control circuit 65 determines whether or not an information request signal is input from work implement 1 via battery TR terminal 64. The information request signal is a signal output from the TR terminal 44 when the control circuit 36 requests the battery pack 22 for a battery information signal.

In S20, if the battery control circuit 65 determines that the information request signal is input, the process proceeds to S30. In S20, if the battery control circuit 65 determines that the information request signal is not input, the process proceeds to S60.

In S30, the battery control circuit 65 determines whether the output signal from the battery DS terminal 63 is a discharge permission signal. If the battery control circuit 65 determines in S30 that the output signal is the discharge permission signal, the routine proceeds to S40. When the battery control circuit 65 determines in S30 that the output signal is a discharge prohibition signal indicating that discharge is prohibited, the routine proceeds to S50.

In S40 and S50, the battery control circuit 65 outputs a plurality of battery information signals including the second signal from the battery TR terminal 64 in response to the information request signal. In S40, the battery control circuit 65 outputs a discharge permission signal indicating permission of discharge as the second signal. In S50, the battery control circuit 65 outputs a discharge prohibition signal indicating that discharge is prohibited, as the second signal. In S40 and S50, the battery control circuit 65 outputs a signal indicating information on the remaining amount of the battery 60 and the overcurrent, and the like, as other battery signals.

In S60, battery control circuit 65 determines whether or not all of the voltage values of the plurality of cells included in battery 60 are equal to or greater than a predetermined voltage value. When any one of the cell voltage values is lower than the predetermined voltage value, the discharge may be continued and the battery 60 may be deteriorated, and therefore, the discharge needs to be stopped to protect the battery 60. Therefore, in S60, the battery control circuit 65 determines whether or not the battery 60 needs to be protected based on the cell voltage value.

If the battery control circuit 65 determines in S60 that any one of the cell voltage values is lower than the predetermined voltage value, the process proceeds to S90. In S90, the battery control circuit 65 stops the output of the discharge permission signal from the battery DS terminal 63. When the discharge enable signal is a high-level signal (hereinafter, referred to as a high signal), when the output of the discharge enable signal is stopped, a low-level signal (hereinafter, referred to as a low signal) corresponding to the discharge disable signal is output from the battery DS terminal 63. When the discharge enable signal is a low signal, if the output of the discharge enable signal is stopped, a high signal corresponding to the discharge disable signal is output from the battery DS terminal 63. That is, when the output of the discharge permission signal from the battery DS terminal 63 is stopped, the discharge prohibition signal is output from the battery DS terminal 63. The battery control circuit 65 immediately outputs a discharge prohibition signal from the battery DS terminal 63 at a timing when the battery 60 needs to be protected.

On the other hand, in S60, when the battery control circuit 65 determines that any one of the cell voltage values is equal to or greater than the predetermined voltage value, the process proceeds to S70. In S70, battery control circuit 65 determines whether or not the value of the discharge current of battery 60 is equal to or less than a predetermined current value. When the value of the discharge current exceeds the predetermined current, the discharge may be continued and the battery 60 may be deteriorated, and therefore, the discharge needs to be stopped to protect the battery 60. Thus, in S70, the battery control circuit 65 determines whether or not the battery 60 needs to be protected based on the value of the discharge current.

In S70, when the battery control circuit 65 determines that the value of the discharge current exceeds the predetermined current value, the process of S90 is performed.

On the other hand, in S70, when the battery control circuit 65 determines that the value of the discharge current is equal to or less than the predetermined current, the process proceeds to S80. In S80, battery control circuit 65 determines whether or not all of the cell temperatures of battery 60 are equal to or lower than a predetermined temperature. When any one of the cell temperatures exceeds the predetermined temperature, the discharge may be continued and the battery 60 may deteriorate, and therefore, the discharge needs to be stopped to protect the battery 60. Thus, in S80, the battery control circuit 65 determines whether or not the battery 60 needs to be protected based on the cell temperature.

In S80, when the battery control circuit 65 determines that any one of the cell temperatures exceeds the predetermined temperature, the process of S90 is performed.

On the other hand, in S80, when the battery control circuit 65 determines that any of the cell temperatures is equal to or lower than the predetermined temperature, the process proceeds to S100. In S100, battery control circuit 65 determines whether work implement 1 is not connected to battery pack 22.

If it is determined in S100 that work implement 1 is connected, battery control circuit 65 returns to S20. On the other hand, if it is determined in S100 that work implement 1 is not connected, battery control circuit 65 proceeds to S110. In S110, the battery control circuit 65 stops the output of the discharge enable signal from the battery DS terminal 63 in the same manner as the processing in S90. This concludes the present process.

< 4. processing in electric working machine >

< 4-1. Main processing >

Next, the main process executed by control circuit 36 of work implement 1 will be described with reference to the flowchart of fig. 4.

First, in S200, the control circuit 36 determines whether or not the time reference has elapsed. If the time reference has not elapsed, the control circuit 36 stands by, and if the time reference has elapsed, the process proceeds to S210. The time reference corresponds to the control period of the control circuit 36.

In S210, the control circuit 36 executes the operation detection process of the trigger switch 12. In detail, the control circuit 36 detects whether the trigger switch 12 is turned on or off based on a signal from the trigger switch 12.

Next, in S220, the control circuit 36 executes battery state processing based on the information output from the battery pack 22. The details of the battery state processing will be described later.

Next, in S230, the control circuit 36 executes AD conversion processing. Specifically, the control circuit 36 AD-converts the detection signals input from the battery voltage detection unit 28, the current detection unit 54, and the temperature detection unit 56. Thereby, the control circuit 36 acquires the value of the current flowing in the motor 50, the voltage value of the battery 60, and the temperature of the switching element.

Next, in S240, the control circuit 36 executes abnormality detection processing. Specifically, the control circuit 36 compares the current value, the voltage value, and the temperature acquired in S230 with respective threshold values to detect an abnormality such as an overcurrent, a decrease in the battery voltage, and a high-temperature state of the switching element. Then, in the case where an abnormality is detected, the control circuit 36 sets the motor abnormality flag.

Next, in S250, the control circuit 36 executes motor control based on the on/off state of the trigger switch 12, the battery state, and the detection result of the abnormality. The details of the motor control process will be described later.

Next, in S260, the control circuit 36 executes display processing. More specifically, the control circuit 36 displays the operating state of the motor 50, the remaining amount of the battery 60, the detected abnormality, and the like, and reports the display to the user. This concludes the present process.

< 4-2. Battery State identification processing >

Next, details of the battery state identification process executed by the control circuit 36 in S220 will be described with reference to the flowchart of fig. 5.

First, in S300, the control circuit 36 executes a battery communication process. Specifically, when detecting that battery pack 22 is attached to work implement 1, control circuit 36 transmits information of work implement 1 to battery pack 22 via TR terminal 44 during initial communication. The information of work implement 1 includes, for example, the model number of work implement 1. In addition, the control circuit 36 receives information of the battery pack 22 from the battery pack 22 via the TR terminal 44. The information of the battery pack 22 includes, for example, the model number of the battery pack 22.

Further, the control circuit 36 transmits an information request signal to the battery control circuit 65 via the TR terminal 44 at a prescribed cycle, and receives battery information from the battery control circuit 65 as a response to the signal information request signal. Here, the period in which the information request signal is transmitted is set to be longer than the period in which the discharge current flows from the battery pack 22 to the work machine 1 when the discharge current does not flow from the battery pack 22 to the work machine 1. That is, when no discharge current flows from battery pack 22 to work implement 1, the frequency of serial communication is set lower than when a discharge current flows.

Next, in S310, the control circuit 36 executes a discharge setting process for setting the discharge state of the battery 60 based on the first signal and the second signal output from the battery pack 22. The details of the discharge setting process will be described later.

Next, in S320, the control circuit 36 executes discharge abnormality processing based on the result of the discharge setting processing. Details of the discharge abnormality processing will be described later. This completes the process.

< 4-3 discharge setting processing >

Next, details of the discharge setting process executed by the control circuit 36 in S310 will be described with reference to the flowchart of fig. 6.

First, in S400, the control circuit 36 determines whether or not the input signal to the DS terminal 43 is the discharge enable signal. Here, the control circuit 36 also receives the discharge prohibition signal when the work machine 1 and the battery pack 22 are not connected, specifically, when the battery DS terminal 63 and the DS terminal 43 are not connected. That is, when the discharge prohibition signal is output via the battery DS terminal 63 and when the battery DS terminal 63 is not connected to the DS terminal 43, the potential of the first connection line 48 is the same potential. The control circuit 36 proceeds to the process of S410 when the input signal is the discharge enable signal, and proceeds to the process of S420 when the input signal is the discharge disable signal.

In S410, the control circuit 36 sets the first permission flag, and proceeds to the process of S430.

In addition, in S420, the control circuit 36 clears the first permission flag, and proceeds to the process of S430.

In S430, the control circuit 36 determines whether or not the communication state with the battery control circuit 65 is a connection state. That is, the control circuit 36 determines whether or not serial communication is established with the battery control circuit 65. Specifically, the control circuit 36 determines the communication state as the connection state when the information request signal is transmitted to the battery control circuit 65 and a response is made, and determines the communication state as the non-connection state when no response is made. If the communication state is determined to be the connection state, the control circuit 36 proceeds to the process of S440. When the communication state is determined to be the non-connection state, the control circuit 36 proceeds to the process of S470.

In S440, the control circuit 36 determines whether the second signal input to the TR terminal 44 is the discharge enable signal. If the second signal is the discharge enable signal, the control circuit 36 sets the second enable flag in S450, and proceeds to the process of S490. In addition, in the case where the second signal is the discharge prohibition signal, the control circuit 36 clears the second permission flag in S460, and proceeds to the process of S490.

On the other hand, in S470, the control circuit 36 determines whether the disconnection time with the battery control circuit 65 is longer than the determination time. Specifically, the control circuit 36 determines whether or not a determination time has elapsed in a state where no response has been made after the information request signal is transmitted to the battery control circuit 65. The determination time is a preset time. If the disconnection time is longer than the determination time, the control circuit 36 clears the second permission flag in S480, and proceeds to the process of S490. Thus, in the case where serial communication with the battery control circuit 65 is not established, the control circuit 36 executes the same processing as in the case where the discharge prohibition signal is received via the TR terminal 44. When the disconnection time is equal to or less than the determination time, the control circuit 36 proceeds to the process of S490 as it is.

In S490, the control circuit 36 determines whether the first permission flag is set. When the first permission flag is set, the control circuit 36 proceeds to the process of S500, and when the first permission flag is not set, the control circuit proceeds to the process of S520.

In S500, the control circuit 36 determines whether the second permission flag is set. If the second permission flag is set, the control circuit 36 proceeds to the process of S510, and if the second permission flag is not set, the control circuit proceeds to the process of S520.

In S510, the control circuit 36 sets the permission discharge flag. That is, the control circuit 36 sets the discharge enable flag only when both the first enable flag and the second enable flag are set. Thus, the discharge of the battery pack 22 is permitted only when both the first signal and the second signal indicate that the discharge is permitted.

On the other hand, in S520, the control circuit 36 will allow the discharge flag to be cleared. That is, when at least one of the first permission flag and the second permission flag is not set, the control circuit 36 clears the discharge permission flag. Thus, when at least one of the first signal and the second signal indicates that discharge is prohibited, discharge of the battery pack 22 is prohibited. This concludes the present process.

< 4-4. discharge abnormality treatment >

Next, details of the discharge abnormality processing executed by the control circuit 36 in S320 will be described with reference to the flowchart of fig. 7.

First, in S600, the control circuit 36 determines whether the motor 50 is being driven. When the motor 50 is being driven, the control circuit 36 proceeds to the process of S610, and when the motor 50 is being stopped, the control circuit proceeds to the process of S630.

In S610, the control circuit 36 determines whether the discharge enable flag is cleared. If the discharge permission flag is cleared, the control circuit 36 sets the first abnormality flag in S620, and proceeds to the process of S650. In addition, in the case where the permission discharge flag is set, the control circuit 36 proceeds to the process of S650 as it is.

On the other hand, in S630, the control circuit 36 determines whether the trigger switch 12 is off. In the case where the trigger switch 12 is turned off, the control circuit 36 clears the first abnormality flag in S640, and proceeds to the process of S650. In addition, when the trigger switch 12 is turned on, the control circuit 36 proceeds to the process of S650 as it is.

In S650, the control circuit 36 determines whether the discharge enable flag is cleared. If the discharge permission flag is cleared, the control circuit 36 proceeds to the process of S660. When the discharge enable flag is set, the control circuit 36 ends the present process.

In S660, the control circuit 36 determines whether the state of the first permission flag and the state of the second permission flag do not coincide. That is, the control circuit 36 determines whether both the first permission flag and the second permission flag are cleared. If one of the first permission flag and the second permission flag is set and the other is cleared, and the states of both flags do not match, the control circuit 36 proceeds to the process of S670. When both the first permission flag and the second permission flag are cleared and the states of both flags match, the control circuit 36 ends the present process.

In S670, the control circuit 36 determines whether the inconsistent state between the first permission flag and the second permission flag continues for a set time or longer. The setting time is set to a period for outputting the information request signal, or a period longer than the period for outputting the information request signal. When the timing at which the battery pack 22 is in the state requiring protection is different from the timing at which the information request signal is output, a period during which the first permission flag and the second permission flag are in the inconsistent state occurs. However, when there is no abnormality in the battery pack 22 and the controller 30, the duration of the inconsistent state between the first permission flag and the second permission flag is shorter than the set time.

When the inconsistent state continues for the set time or longer, the control circuit 36 sets the second abnormality flag in S680, and ends the present process. By setting the second abnormality flag, even when the trigger switch 12 is turned on again, the re-driving of the motor 50 is prohibited when a predetermined cancel condition is not satisfied. The predetermined release condition is (i) to remove battery pack 22 from work implement 1. When the battery pack 22 is removed from the work machine 1 and no power is supplied to the control circuit 36, the inhibition of the re-driving of the motor 50 is canceled. On the other hand, when the duration of the inconsistent state is shorter than the set time, the control circuit 36 ends the present process as it is.

The predetermined release condition may include (ii) that work implement 1 is not operated for a predetermined time or longer and (iii) that main switch 24 of work implement 1 is turned off, in addition to condition (i). When the predetermined cancellation condition includes the conditions (i) to (iii), the prohibition of the re-driving of the motor 50 is cancelled when any of the conditions (i) to (iii) is satisfied.

< 4-5. Motor control processing >

Next, details of the motor control process executed by the control circuit 36 in S250 will be described with reference to the flowchart of fig. 8.

First, in S800, the control circuit 36 determines whether or not the trigger switch 12 is turned on. When the trigger switch 12 is on, the control circuit 36 proceeds to the process of S810, and when the trigger switch 12 is off, the control circuit proceeds to the process of S840.

In S810, the control circuit 36 determines whether or not there is no abnormality in the motor 50, the controller 30, and the battery pack 22. Specifically, the control circuit 36 determines whether or not the motor abnormality flag, the first abnormality flag, and the second abnormality flag are set. If any of the abnormality flags is not set, the control circuit 36 proceeds to the process of S820. If any of the abnormality flags is set, the control circuit 36 proceeds to the process of S840.

In S820, the control circuit 36 determines whether the discharge enable flag is set. If the discharge enable flag is set, the control circuit 36 proceeds to the process of S830, and if the discharge enable flag is cleared, the control circuit proceeds to the process of S840.

In S830, the control circuit 36 receives the power supply from the battery 60 and executes the motor driving process. In detail, the control circuit 36 calculates the rotational position and the rotational speed of the motor 50 based on the rotation detection signal from the rotation sensor 52. The control circuit 36 sets the target rotation speed of the motor 50 based on the setting of the shift dial 23, and sets the rotation direction of the motor 50 based on the setting of the forward/reverse changeover switch 9. Then, the control circuit 36 calculates a Pulse Width Modulation of each switching element of the drive circuit 32 using the calculated rotation speed of the motor 50: a Pulse Width Modulation (PWM) duty ratio is set so that the rotation speed of the motor 50 in the set rotation direction converges to the target rotation speed. Further, the control circuit 36 outputs a control signal corresponding to the calculated PWM duty to the gate circuit 34, and ends the present process.

On the other hand, in S840, the control circuit 36 determines whether or not to perform the braking control. Specifically, the control circuit 36 determines to execute the braking control when the motor 50 is rotated and the controller 30 is not affected by the braking force generated by the motor 50. In this case, the control circuit 36 sets the brake flag in S850, and ends the present process. Thereby, the supply of electric power from the battery 60 to the motor 50 is stopped, and short-circuit braking is performed.

On the other hand, when the motor 50 is not rotating, or when the controller 30 is affected by the braking force generated by the motor 50 even though the motor 50 is rotating, the control circuit 36 determines not to perform the braking control. In this case, the control circuit 36 clears the brake flag in S860, and ends the present process. Thereby, the supply of electric power from the battery 60 to the motor 50 is stopped. Then, when the motor 50 rotates, idling or the like is performed.

< 5. Effect >

According to the first embodiment described above, the following effects can be obtained.

(1) The work machine 1 includes: a DS terminal 43 receiving the first signal and a TR terminal 44 receiving the second signal. Therefore, even when a failure occurs in work machine 1 in which the signal indicating that discharge is permitted is received via either one of DS terminal 43 and TR terminal 44 despite the first signal and the second signal indicating that discharge is prohibited being transmitted from battery pack 22, the signal indicating that discharge is prohibited can be received via the other terminal. This can appropriately protect the battery pack 22 and suppress deterioration of the battery pack 22.

(2) The second signal is input using a TR terminal 44 to which a battery signal other than a signal indicating permission or inhibition of discharge is input. Thus, work implement 1 can receive the first signal and the second signal from battery pack 22, and protect battery pack 22 doubly without increasing the number of terminals. Further, battery pack 22 can transmit the first signal and the second signal to work implement 1 without increasing the number of terminals.

(3) Work machine 1 can receive the discharge prohibition signal via DS terminal 43 in real time when battery pack 22 is in the discharge prohibition state. Further, work implement 1 can receive a second signal based on the state of battery pack 22 in response to the information request signal transmitted by itself. That is, when battery pack 22 enters the discharge prohibition state upon receiving the information request signal, work machine 1 can receive the discharge prohibition signal via TR terminal 44.

(4) When DS terminal 43 is not connected to battery pack 22, work implement 1 receives a discharge prohibition signal via DS terminal 43. Accordingly, work implement 1 can protect battery pack 22 by inhibiting discharge of battery pack 22 when DS terminal 43 is not connected to battery pack 22.

(5) Work machine 1 can receive a plurality of battery signals via TR terminal 44. Further, in a case where serial communication is not established between work implement 1 and battery pack 22, work implement 1 executes the same processing as in a case where the discharge prohibition signal is received via TR terminal 44. Thus, work implement 1 can protect battery pack 22 by inhibiting discharge of battery pack 22 when serial communication is not established between work implement 1 and battery pack 22.

(6) When no discharge current flows from battery pack 22 to work implement 1, work implement 1 is less likely to change the state of battery 60 than when a discharge current flows. Thus, when no discharge current flows from battery pack 22 to work implement 1, the frequency of serial communication can be suppressed lower than when a discharge current flows. This can suppress the load on the control circuit 36 and the battery control circuit 65 of the work machine 1.

(7) When the control circuit 36 receives the discharge prohibition signal from one of the DS terminal 43 and the TR terminal 44 but does not receive the discharge prohibition signal from the other, there is a possibility that an abnormality occurs. In this case, the work machine 1 can protect the battery pack 22 by prohibiting the re-driving of the motor 50 unless a predetermined condition is satisfied even if the trigger 11 is operated.

(8) The DS connection path and the serial connection path are mutually independent and different paths including no common part. Therefore, the battery pack 22 can be protected reliably doubly.

(9) The control circuit 36 drives the motor 50 only when receiving the discharge enable signal via the DS terminal 43 and receiving the discharge enable signal via the TR terminal 44. Therefore, even if the first signal and the second signal indicating that the discharge is prohibited are output from the battery pack 22, the battery pack 22 can be protected when the discharge permission signal is received only at one of the DS terminal 43 and the TR terminal 44.

(second embodiment)

< 2-1. different points from the first embodiment >

Next, since the basic configuration of the second embodiment is the same as that of the first embodiment, the description of the common configuration will be omitted, and the differences will be mainly described. Note that the same reference numerals as those in the first embodiment denote the same structures, and the above description is referred to.

In the first embodiment, when battery pack 22 is in a state to be protected, two kinds of discharge prohibition signals are transmitted from battery DS terminal 63 and battery TR terminal 64 to controller 30 of work machine 1. In contrast, the second embodiment is different from the first embodiment in that three types of discharge prohibition signals are transmitted from battery DS63 and battery TR terminal 64 to controller 30 of work implement 1 when battery pack 22 is in a state to be protected. In the second embodiment, the battery control circuit 65 and the controller 30 perform half-duplex serial communication with the battery control circuit 65 as the main component and the controller 30 as the auxiliary component.

< 2-2. Structure of Motor control System

Next, the configuration of the motor control system 200 according to the second embodiment will be described with reference to fig. 9.

The motor control system 200 includes, in addition to the configuration of the motor control system 100: fuse 66 with self-blowing control (hereinafter referred to as fuse 66), shunt resistor 67, latch circuit 35, buffer 37, and stop circuit 39.

The fuse 66 and the shunt resistor 67 are provided in the battery pack 22. The fuse 66 is provided on a positive electrode line connecting the positive electrode of the battery 60 and the battery positive electrode terminal 61. The shunt resistor 67 is provided on a negative electrode line connecting the negative electrode of the battery 60 and the battery negative electrode terminal 62.

In the case where the discharge is not stopped even if the three types of discharge prohibition signals are output from the battery pack 22, the battery control circuit 65 issues an instruction to blow the fuse 66 as a final method for ensuring safety. The fuse 66 is blown off, the positive electrode wire is disconnected, and the battery 60 is in a state of being unusable. The battery control circuit 65 detects a discharge current and a charge current flowing through the battery 60 via the shunt resistor 67. In the present embodiment, the shunt resistor 67 corresponds to an example of the detection unit.

The latch circuit 35, the stop circuit 39, and the buffer 37 are provided in the controller 30 of the work machine 1. The latch circuit 35 includes two input terminals and one output terminal. The first input terminal is connected to the first connection line 48. The second input terminal is connected to a connection line connecting the trigger SW12 and the control circuit 36. The output terminal is connected to the stop circuit 39.

The stop circuit 39 is provided in six output paths for outputting the motor control signals of three phases from the control circuit 36 to the gate circuit 34. The stop circuit 39 includes switching elements provided in the six output paths, respectively. The buffer 37 is provided on the first connection line 48. Specifically, the latch circuit is provided between the control circuit 36 and a connection point between the first input terminal of the latch circuit 35 and the first connection line 48.

When the discharge enable signal is input from the first input terminal and the on signal of the trigger SW12 is input from the second input terminal, the latch circuit 35 outputs a signal for turning on each switching element of the stop circuit 39. When the discharge prohibition signal is input from the first input terminal in a state where the signal for turning on each switching element of the stop circuit 39 is output, the latch circuit 35 outputs a signal for latching each switching element of the stop circuit 39 off until the off signal of the trigger SW12 is input from the second input terminal. That is, the latch circuit 35 maintains the discharge prohibition state until the trigger SW12 turns off in response to the input of the discharge prohibition signal. This can suppress sudden operation of the motor 50 even if the discharge prohibition signal input from the DS terminal 43 disappears due to a failure of the battery control circuit 65 or the like.

The buffer 37 transmits a signal in one direction from the DS terminal 43 to the control circuit 36. If the buffer 37 is not provided, the control circuit 36 may run away, and the discharge enable signal may be output from the control circuit 36 to the first input terminal of the latch circuit 35. Further, the switching element of the stop circuit 39 may be turned on by mistake. By providing the buffer 37 between the control circuit 36 and the connection point between the first input terminal of the latch circuit 35 and the first connection line 48, even when the discharge enable signal is erroneously output from the control circuit 36, the discharge enable signal is not input to the first input terminal of the latch circuit 35. Further, it is possible to avoid erroneous turning on of the switch of the stop circuit 39.

< 2-3. discharge treatment

Next, a discharge control process performed by the battery control circuit 65 will be described with reference to the flowchart of fig. 10.

First, in S15, it is determined whether or not the battery 60 is in an overdischarge state. If it is determined at S15 that the vehicle is not in the overdischarge state, the process proceeds to S25, and a discharge permission signal (specifically, a low signal) is transmitted to work machine 1 via battery DS terminal 63. Thereafter, the process proceeds to S35.

At S35, work implement 1 determines whether or not it is not connected to battery pack 22. When the work machine 1 is not connected, the present process is ended. When the work machine 1 is connected to the battery pack, the process returns to S15.

On the other hand, if it is determined in S15 that the battery is in the overdischarge state, in S45, a discharge prohibition signal according to the communication protocol is transmitted to the controller 30 by serial communication via the battery TR terminal 64, and the controller 30 is requested to stop discharge. The discharge prohibition signal transmitted in S45 is a multi-bit signal, and each bit is represented by either a high signal whose voltage is high or a low signal whose voltage is low according to the communication protocol. In the present embodiment, the discharge prohibition signal transmitted in S45 corresponds to an example of the third signal.

Next, in S55, it is determined whether the overdischarge state is continued for a time TA1 after the overdischarge state is detected. That is, it is determined whether the overdischarge state continues although the discharge stop is requested in S45. TA1 is for example 0.5 s. If it is determined at S45 that the time period TA1 has not been continued, the process proceeds to S25. On the other hand, if it is determined at S45 that the time TA1 has continued, the process proceeds to S65.

In S65, a discharge prohibition signal that is not in accordance with the communication protocol is sent to controller 30 via battery TR terminal 64. The discharge prohibition signal that does not depend on the communication protocol is a signal of a fixed voltage level, a signal of a higher cycle than a normal clock signal, a random signal, or the like.

In the present embodiment, a signal having a fixed voltage level is used as the discharge prohibition signal that does not comply with the communication protocol. Specifically, battery TR terminal 64 outputs either a high signal or a low signal, and outputs a low signal while waiting for serial communication. That is, while waiting for serial communication, battery TR terminal 64 fixes the voltage level to the low level. In contrast, when a signal not compliant with the communication protocol is output, battery TR terminal 64 fixes the voltage level to a high level. The discharge-prohibition signal that does not depend on the communication protocol is a signal composed of a continuous high signal.

When the battery 60 is overloaded, noise is easily superimposed on the serial communication. By setting the discharge prohibition signal to a signal fixed at a constant voltage level, noise resistance is improved, and the discharge prohibition signal can be transmitted to the controller 30 with higher reliability. Battery TR terminal 64 may be configured to fix the voltage level to a high level when waiting for serial communication and to fix the voltage level to a low level when outputting a discharge prohibition signal that does not comply with the communication protocol. That is, the discharge prohibition signal that is not in accordance with the communication protocol may be a signal composed of a continuous low signal. In the present embodiment, the discharge prohibition signal transmitted in S55 corresponds to an example of the fourth signal.

Next, in S75, it is determined whether or not the discharge current continues to flow for a time TB1 or more after a discharge prohibition signal (specifically, a high signal) that does not comply with the communication protocol is transmitted via the battery TR terminal 64 in S65. TB1 is for example 0.5 s.

If it is determined at S75 that the discharge current is not continuously flowing, the process proceeds to S25. On the other hand, if it is determined in S75 that the discharge current continues to flow, the process proceeds to S85.

In S85, a discharge prohibition signal is sent to the controller 30 via the battery DS terminal 63. Specifically, the battery DS terminal 63 is set to a high impedance state.

Next, in S95, it is determined whether or not the discharge current continues for a time TC1 or more after the discharge prohibition signal is sent via the battery DS terminal 63 in S85. TC1 is, for example, 0.75 s.

If it is determined at S95 that the discharge current does not continue to flow, the process proceeds to S35. On the other hand, if it is determined in S95 that the discharge current continues to flow, the process proceeds to S105.

In S105, a fuse blow command for the fuse 66 is output to blow the fuse 66. Thereby, the discharge from the battery 60 is stopped. This completes the process.

< 2-4. inhibit discharge action >

Fig. 11 shows the discharge inhibiting operation in the case where the flowchart shown in fig. 10 is executed. First, when the over-discharge voltage is detected at time t0, a discharge prohibition signal is transmitted from the battery control circuit 65 to the controller 30 by serial communication at time t 1. That is, in response to the battery pack 22 being in a state to be protected, the discharge prohibition signal is first transmitted by serial communication. The controller 30 receives the discharge prohibition signal by serial communication, and can recognize the state of the battery pack 22 and appropriately perform processing.

Next, at time t2 when time TA1 has elapsed from time t0, the discharge prohibition signal whose voltage level is fixed at the high level is transmitted via the battery TR terminal 64 without canceling the over-discharge state. If the over-discharge state of the battery 60 cannot be eliminated even if the discharge prohibition signal is transmitted by serial communication, noise may overlap with the serial communication, and the controller 30 may not receive the discharge prohibition signal. This transmits a discharge prohibition signal having high noise resistance.

Next, when the discharge is not stopped at time t3 when the time TB1 has elapsed from time t2, a discharge prohibition signal is transmitted via the battery DS terminal 63. When the discharge prohibition signal is input from the battery DS terminal 63 to the latch circuit 35 via the DS terminal 43, the switch of the stop circuit 39 is turned off. As a result, the discharge-inhibited state is maintained as long as the predetermined condition is not satisfied. Therefore, the discharge prohibition signal passing through the battery DS terminal 63 among the three kinds of discharge prohibition signals is finally transmitted.

Next, when the discharge is not stopped at time t4 when time TC1 has elapsed from time t3, fuse 66 melts. That is, when the discharge of the battery 60 is not stopped even if the three types of discharge prohibition signals are transmitted from the battery control circuit 65 to the controller 30, the fuse 66 is blown as the last method.

According to the second embodiment described above, the following effects are obtained in addition to the effects (1) to (9) of the first embodiment.

(10) A discharge prohibition signal is sent from the battery control circuit 65 to the controller 30 via the battery DS terminal 63. In addition, a discharge prohibition signal in accordance with the communication protocol and a discharge prohibition signal not in accordance with the communication protocol are transmitted from the battery control circuit 65 to the controller 30 via the battery TR terminal 64. Thereby, a total of three types of discharge prohibition signals can be transmitted from the battery control circuit 65 to the controller 30. Therefore, the battery pack 22 can be appropriately protected against deterioration.

(11) A signal whose voltage level is fixed to a high level is continuously transmitted from battery TR terminal 64 as a signal not complying with the communication protocol. The signal with a fixed voltage level has higher noise resistance than a signal with a fluctuating voltage level. Therefore, by outputting a discharge inhibiting signal having a fixed voltage level and a plurality of bits when the battery 60, which is likely to be superimposed with noise, is over-discharged, the reliability of receiving the discharge inhibiting signal by the controller 30 can be improved.

(12) In response to the battery 60 becoming the overdischarge state, a discharge prohibition signal is first transmitted from the battery TR terminal 64 by serial communication. Thus, the controller 30 can recognize the state of the battery pack 22 before the discharge is stopped, and perform processing in accordance with the state of the battery pack 22.

(13) In response to the battery 60 becoming a state to be protected, a discharge prohibition signal is first transmitted via the battery TR terminal 64 not connected to the latch circuit 35. This can suppress the processing load on the battery control circuit 65 and the controller 30 associated with the release of the latch circuit 35, and avoid the work implement 1 from suddenly operating.

(14) In the case where a discharge current flows even if three kinds of discharge prohibition signals are sent from the battery control circuit 65 to the controller 30, the fuse 66 is blown. Thus, when the discharge of the battery pack cannot be stopped in a usable state, the battery pack 22 can be set to a non-usable state, and the safety of the battery pack can be ensured.

(third embodiment)

< 3-1. different from the second embodiment

Next, since the basic configuration of the third embodiment is the same as that of the second embodiment, the description of the common configuration will be omitted, and the differences will be mainly described. Note that the same reference numerals as those in the second embodiment denote the same structures, and the above description is referred to.

The third embodiment differs from the second embodiment in the order of outputting the three discharge prohibition signals. In the third embodiment, the battery control circuit 65 and the controller 30 perform half-duplex serial communication with the battery control circuit 65 as a slave and the controller 30 as a master. The motor control system 200 of the third embodiment has the same configuration as that of the second embodiment.

< 3-2. discharge control processing >

Next, a discharge control process performed by the battery control circuit 65 will be described with reference to the flowchart of fig. 12.

First, in S205, it is determined whether or not the battery 60 is in an overdischarge state. If it is determined in S205 that the vehicle is not in the overdischarge state, the process proceeds to S215, and a discharge permission signal (specifically, a low signal) is transmitted to work implement 1 via battery DS terminal 63. Thereafter, the process proceeds to S225.

In S225, it is determined whether or not work implement 1 is not connected to battery pack 22. When the work machine 1 is not connected, the present process is ended. When the work machine 1 is connected to the battery pack, the process returns to S205.

On the other hand, when it is determined in S205 that the battery is in the overdischarge state, it is determined in S235 whether or not the serial communication request is received from the controller 30 via the battery TR terminal 64. If it is determined in S235 that the serial communication request has been received, the process proceeds to S245. If it is determined in S235 that the serial communication request has not been received, the process in S245 is skipped, and the process proceeds to S255.

In S245, a discharge stop signal in accordance with the communication protocol is transmitted by serial communication via the battery TR terminal 64, and the controller 30 is requested to stop discharge. The discharge prohibition signal according to the communication protocol is the same signal as that of the second embodiment.

Next, in S255, it is determined whether the overdischarge state continues for a time TA2 after the overdischarge state is detected. TA2 is for example 0.5 s. If it is determined in S255 that the time period TA2 has not continued, the process proceeds to S215. On the other hand, if it is determined in S255 that the time TA2 has continued, the process proceeds to S265.

In S265, the battery DS terminal 63 is set to a high impedance state, and a discharge prohibition signal is transmitted to the controller 30 via the battery DS terminal 63.

Next, in S275, it is determined whether or not the discharge current continues to flow for a time period TB2 or more after the discharge prohibition signal is sent via battery DS terminal 63 in S265. TB2 is for example 0.25 s.

If it is determined in S275 that the discharge current does not continuously flow, the process proceeds to S225. On the other hand, if it is determined in S275 that the discharge current continues to flow, the process proceeds to S285.

In S285, a discharge prohibition signal that is not in accordance with the communication protocol is transmitted to controller 30 via battery TR terminal 64. The discharge prohibition signal that does not depend on the communication protocol is the same signal as the second embodiment.

Next, in S295, it is determined whether or not the discharge current continues for a time period TC2 or longer after the discharge prohibition signal not complying with the communication protocol is transmitted via the battery TR terminal 63 in S285. TC2 is, for example, 0.75 s.

If it is determined in S295 that the discharge current does not continuously flow, the process proceeds to S225. On the other hand, if it is determined in S295 that the discharge current continues to flow, the process proceeds to S305.

In S305, a blowing command for the fuse 66 is output to blow the fuse 66. Thereby, the discharge from the battery 60 is stopped. This completes the process.

< 3-3. inhibit discharge action >

Fig. 13 shows a discharge inhibiting operation in the case where the flowchart shown in fig. 12 is executed. First, at time t10, an overdischarge voltage is detected. When the battery control circuit 65 receives a communication request from the controller 30 at time t11, a discharge prohibition signal is output from the battery control circuit 65 to the controller 30 by serial communication at time t 12.

Next, at time t13 when the time TA2 has elapsed from time t10, the discharge prohibition signal is transmitted via the battery DS terminal 63 without canceling the overdischarge state. The battery control circuit 65 is in serial communication with the controller 30 periodically. Therefore, depending on the communication timing, there may be a case where the battery control circuit 65 does not receive the communication request from the time t10 to the time t 13. In this case, the discharge prohibition signal that passes through the battery DS terminal 63 among the three kinds of discharge prohibition signals is first transmitted.

Next, at time t14 when the time TB2 has elapsed from time t13, if the discharge is not stopped, the discharge prohibition signal not complying with the protocol is transmitted via the battery TR terminal 64. Next, at time t15 when time TC2 has elapsed from time t14, when the discharge is not stopped, fuse 66 is blown.

According to the third embodiment described above, the effects (1) to (9) of the first embodiment and the effects (10), (11), and (14) of the second embodiment are exhibited. Further, when the discharge prohibition signal is transmitted by serial communication via the battery TR terminal 64 before the discharge prohibition signal is transmitted via the battery DS terminal 63, the effects (12) and (13) of the second embodiment are obtained.

(fourth embodiment)

< 4-1. different from the second embodiment >

Next, since the basic configuration of the fourth embodiment is the same as that of the second embodiment, the description of the common configuration will be omitted, and the differences will be mainly described. Note that the same reference numerals as those in the second embodiment denote the same structures, and the above description is referred to.

The third embodiment differs from the second embodiment in the order of outputting the discharge prohibition signals. In the fourth embodiment, the battery control circuit 65 and the controller 30 perform half-duplex serial communication with the battery control circuit 65 as a slave and the controller 30 as a master. The motor control system 200 of the fourth embodiment has the same configuration as that of the second embodiment.

< 4-2. discharge control processing

Next, a discharge control process performed by the battery control circuit 65 will be described with reference to the flowchart of fig. 14.

First, in S405, it is determined whether or not the battery 60 is in an overdischarge state. If it is determined in S405 that the vehicle is not in the overdischarge state, the process proceeds to S415, and a discharge permission signal (specifically, a low signal) is transmitted to work implement 1 via battery DS terminal 63. After that, the process proceeds to S425.

In S425, it is determined whether or not work implement 1 is not connected to battery pack 22. When the work machine 1 is not connected, the present process is ended. When the work machine 1 is connected to the battery pack, the process returns to S405.

On the other hand, if it is determined in S405 that the vehicle is in the overdischarge state, the process proceeds to S435. In S435, the battery DS terminal 63 is set to a high impedance state, and a discharge prohibition signal is transmitted to the controller 30 via the battery DS terminal 63.

Next, in S445, it is determined whether or not a serial communication request is received from the controller 30 via the battery TR terminal 64. If it is determined in S445 that the serial communication request has been received, the process proceeds to S455. If it is determined in S445 that the serial communication request has not been received, the process in S455 is skipped, and the process proceeds to S465.

In S465, it is determined that the discharge current continues to flow for a time TA3 or longer after the discharge prohibition signal is sent in S265 via the battery DS terminal 63 in S435. TA3 is for example 0.75 s.

If it is determined in S465 that the discharge current does not continuously flow, the process proceeds to S425. On the other hand, if it is determined in S465 that the discharge current continues to flow, the process proceeds to S475.

In S475, a discharge prohibition signal that is not in accordance with the communication protocol is transmitted to the controller 30 via the battery TR terminal 64. The discharge prohibition signal that does not depend on the communication protocol is the same signal as the second embodiment.

Next, in S485, it is determined whether or not the discharge current continues for a time period TB3 or longer after the discharge prohibition signal not conforming to the communication protocol is transmitted via the battery TR terminal 63 in S475. TB3 is for example 0.75 s.

If it is determined in S485 that the discharge current does not continuously flow, the process proceeds to S425. On the other hand, if it is determined in S485 that the discharge current continues to flow, the process proceeds to S495.

In S495, a fuse blow command for fuse 66 is output to blow fuse 66. Thereby, the discharge from the battery 60 is stopped. This completes the process.

< 4-3. inhibit discharge action >

Fig. 14 shows a discharge prohibition operation in the case where the flowchart shown in fig. 15 is executed. First, when an overdischarge voltage is detected at time t20, a discharge prohibition signal is transmitted via the battery DS terminal 63 at time t 21. In the present embodiment, since the battery control circuit 65 is auxiliary, the discharge prohibition signal cannot be transmitted by serial communication until the communication request is received from the controller 30. Therefore, there is a possibility that a time lag occurs from the detection of the over-discharge voltage to the transmission of the discharge prohibition signal by the serial communication. Therefore, by first outputting the discharge prohibition signal via the battery DS terminal 63, the discharge can be stopped as soon as possible.

Next, when the battery control circuit 65 receives a communication request from the controller 30 at time t22, a discharge prohibition signal is output from the battery control circuit 65 to the controller 30 by serial communication at time t 23.

Next, when the discharge is not stopped at time t24 when the time TA3 has elapsed from time t21, a discharge prohibition signal not complying with the protocol is transmitted via the battery TR terminal 64. Further, depending on the communication timing between the battery control circuit 65 and the controller 30, there may be a case where the battery control circuit 65 does not receive the communication request from the time t21 to the time t 24. Next, when the discharge is not stopped at time t25 when time TB3 has elapsed from time t24, fuse 66 melts.

According to the third embodiment described above, the effects (1) to (9) of the first embodiment and the effects (10), (11), and (14) of the second embodiment are exhibited. Further, when the over-discharge voltage of the battery 60 is detected, the discharge prohibition signal is immediately transmitted from the battery DS terminal 63, and the discharge can be stopped as soon as possible.

(other embodiments)

While the present disclosure has been described with reference to the embodiments, the present disclosure is not limited to the embodiments described above and can be modified in various ways.

(a) The present disclosure is not limited to application to a weeding machine, and can be applied to various working machines configured to drive a working tool with a rotary force, such as an electric tool such as a chain saw, a hedge trimmer, a hair cutter, and a hammer drill.

(b) The control Circuit 36 and the battery control Circuit 65 may include a combination of various independent electronic components instead of or in addition to the microcomputer, and may include an Application specific Integrated Circuit: an Application Specific Integrated Circuit (ASIC), which may further include: application Specific Standard Products (ASSP), for example, may also include Field Programmable Gate Array: a programmable logic device such as a Field Programmable Gate Array (FPGA), or a combination thereof may be provided.

(c) The number of communication lines constituting each of second connection line 49 and second battery connection line 69 is not limited to one, and may be two. When the second connection line 49 and the second battery connection line 69 include two communication lines, one communication line is a dedicated transmission line for transmitting data from the control circuit 36 to the battery control circuit 65, and the other communication line is a dedicated transmission line for transmitting data from the battery control circuit 65 to the control circuit 36. When the second connection line 49 and the second battery connection line 69 include two communication lines, the serial terminal 44 and the battery serial terminal 64 include two terminals for serial communication, respectively. The two communication lines are connected to terminals for serial communication, respectively. As described above, when the second connection line 49 and the second battery connection line 69 include two communication lines, the communication speed between the control circuit 36 and the battery control circuit 65 can be increased as compared with the case where only one communication line is included.

(d) The plurality of functions of one component in the above embodiments may be realized by a plurality of components, or the plurality of functions of one component may be realized by a plurality of components. Further, a plurality of functions provided by a plurality of components may be realized by one component, or one function realized by a plurality of components may be realized by one component. In addition, a part of the structure of the above embodiment may be omitted. At least a part of the structure of the above embodiment may be added to or replaced with the structure of the other above embodiment.

(e) The present disclosure can be implemented in various forms such as a system including the electric working machine and the battery pack as components, in addition to the electric working machine and the battery pack described above.