JPWO2019031274A1 - Battery pack and electric equipment using battery pack - Google Patents

Abstract

The startup / shutdown of the circuit on the power tool body side and the startup / shutdown of the microcomputer on the battery pack side are linked. A battery pack 100 having an LD terminal 168 for sending a stop signal to a main body of an electric device to be mounted, battery cells 146a to 146e, a microcomputer 250a for monitoring a load state of the battery cells, and a power supply circuit 221 for driving the microcomputer 250a. In addition, a power management circuit 222 for controlling the start and stop of the power circuit 221 for supplying the operation voltage VDD1 is provided. By inputting the voltage of the LD terminal 168, the power management circuit 222 stops the power circuit 221 in conjunction with the shutdown of the device-side microcomputer 60a, and also shuts down the microcomputer 250a on the battery pack side. When the device-side microcomputer 60a is activated, the power supply management circuit 222 activates the microcomputer 250a by operating the power supply circuit 221 and supplying the operating voltage VDD1 to the microcomputer 250a.

Description

The present invention relates to an electric device having a load such as a motor and lighting, and a battery pack for supplying power to such an electric device.

Electric devices such as electric tools are driven by battery packs using secondary batteries such as lithium-ion batteries, and cordless electric devices are becoming more cordless. For example, in a hand-held power tool that drives a tool bit by a motor, a battery pack containing a plurality of secondary battery cells is used, and the motor is driven by electric energy stored in the battery pack. The battery pack is configured to be detachable from the power tool main body, and when the voltage is reduced by discharging, the battery pack is removed from the power tool main body and charged using an external charging device.

In cordless power tools and electric appliances, it is required to secure a predetermined operation time and a predetermined output, and higher output and higher voltage have been achieved with the improvement in performance of secondary batteries. Also, with the development of electric equipment using a battery pack as a power source, battery packs of various voltages have been commercialized. Further, in recent years, a battery pack has been proposed in which the battery pack includes an MCU (Micro Controller Unit, hereinafter referred to as a “microcomputer”) so that power management is performed with high accuracy on the battery pack side. Patent Literature 1 is known as a battery pack having a microcomputer on the battery pack side.

JP 2005-224909 A

The electric device main body using a battery pack includes not only a device having a main switch but also an electric device main body without a main switch and only a trigger switch. In the case of an electric device main body without a main switch, a microcomputer on the main body side is started when a battery pack is mounted on the electric device main body. On the other hand, in order to minimize the power consumption of the battery pack by the microcomputer, a shutdown mode that turns off the power of the microcomputer is provided, and the electric device body is not used for a predetermined time regardless of the state of the battery pack attached In this case, the operation of the microcomputer is stopped by stopping the power supply to the microcomputer. By such control, power consumption by the microcomputer on the electric device main body side is suppressed as much as possible. This type of control can be used to control the power consumption of the microcomputer on the main unit.However, if a microcomputer is also provided in the control unit on the battery pack side, the problem is how to manage the power saving of the microcomputer on the battery pack side. Become.

The present invention has been made in view of the above background, and an object of the present invention is to provide a high-precision battery pack using a microcomputer in a battery pack having a plurality of battery cells by a secondary battery which is a power source between electric devices. It is an object of the present invention to provide a battery pack that realizes a protection function and minimizes power consumption by a microcomputer and an electric device using the battery pack. Another object of the present invention is to configure a microcomputer on the battery pack side so that it can be shut down, perform efficient power management on the battery pack side by shutting down, and use the microcomputer even when storing for a long time. An object of the present invention is to provide a battery pack capable of suppressing self-consumption of electric power and an electric device using the battery pack. Still another object of the present invention is to provide a battery pack and a battery pack capable of shifting a microcomputer operating in a normal mode to a sleep mode or a shutdown mode according to a connection state of a partner device to be mounted and an operation state. An object of the present invention is to provide an electric device using the same.

The typical features of the invention disclosed in the present application will be described as follows. According to one aspect of the present invention, a positive electrode terminal, a negative electrode terminal, an LD terminal for sending a stop signal to a mounted electric device main body, a plurality of battery cells, and a voltage of the battery cells are monitored. A battery pack having a protection circuit, a microcomputer connected to the protection circuit for monitoring the load state of the battery cells, and a power supply circuit for driving the microcomputer, wherein the device includes a device-side microcomputer in the electric device body. When the device-side microcomputer judges that it has shifted to the power saving mode, it shifts to the power saving mode. Here, the power saving mode is either a sleep mode (intermittent operation mode) or a shutdown (power off of the microcomputer). In addition, a power management circuit is provided to activate the power circuit according to the presence or absence of the voltage of the LD terminal. The power management circuit operates the power circuit when the voltage of the LD terminal is present, and the microcomputer operates in response to the disappearance of the voltage of the LD terminal. Then, the power supply circuit is stopped, or the power supply circuit is stopped after a lapse of a fixed time after the power supply is turned off.

According to still another feature of the present invention, the LD terminal of the battery pack is connected to the ground via the switching element, and the microcomputer controls the gate signal of the switching element to make the switching element conductive so that the LD terminal is connected. The operation stop signal is transmitted to the main body of the electric device by being grounded to the ground. Also, the microcomputer can output a self-holding signal for maintaining the ON state of the power supply circuit to the power management circuit, and the power supply circuit stops operating due to the disappearance of the voltage of the LD terminal and the disappearance of the self-holding signal. Configured. The operation modes of the microcomputer include a normal mode in which the processor operates continuously and a sleep mode in which the processor operates intermittently. The power supply circuit is being activated, and a discharge current equal to or greater than the threshold value I _min does not flow. If the state continues for a certain period of time, the mode is shifted from the normal mode to the sleep mode. By shifting to the sleep mode, the amount of power consumed by the microcomputer in the battery pack can be saved.

According to still another feature of the present invention, the microcomputer, when operating in the sleep mode, detects a predetermined current value (discharge current equal to or more than the threshold value _Imin ) at which the operation of the electric device main body is estimated, and the sleep mode. To return to the normal mode. Further, the microcomputer maintains the startup state at least while the device-side microcomputer is running, and shifts to the power-saving mode when the device-side microcomputer shifts to the power-saving mode. In this way, the microcomputer on the battery pack side operates in the normal mode only when the microcomputer on the electric device side is running, so that the microcomputer on the battery pack side works in conjunction with the microcomputer on the battery pack side to achieve highly accurate and efficient battery management. Function can be realized. Further, the microcomputer determines whether the device-side microcomputer is included in the electric device body by comparing the voltage of the positive terminal of the battery pack with the voltage of the LD terminal. The voltage of the LD terminal on the electrical device side when mounted on the electrical device body is the power supply voltage level of the microcomputer when the electrical device body has the device side microcomputer, and the device side microcomputer is not included in the electrical device body side In this case, it is the voltage level of the positive terminal of the battery pack. When it is determined that the device-side microcomputer is not included in the electric device body, the microcomputer on the battery pack side detects that the non-use state of the electric device body has continued for a predetermined time or more while operating in the normal mode. Move to sleep mode. When the use of the electric device body is detected during operation in the sleep mode, the microcomputer on the battery pack shifts from the sleep mode to the normal mode. Further, when the disappearance of the voltage of the LD terminal is detected during the operation in the normal mode or the sleep mode, the microcomputer on the battery pack side shuts itself down after a certain period of time.

According to still another aspect of the present invention, a positive electrode terminal, a negative electrode terminal, an LD terminal for sending a stop signal to a mounted electric device main body, a plurality of battery cells, and a voltage of the battery cells are monitored. A terminal voltage detection circuit that detects a voltage of an LD terminal and outputs the voltage to a microcomputer in a battery pack having a protection circuit, a microcomputer connected to the protection circuit for monitoring a load state of a battery cell, and a power supply circuit for driving the microcomputer. Was provided. The microcomputer determines whether the device-side microcomputer of the electric device body has shut down based on a change in the voltage of the LD terminal, and shuts itself down when the device-side microcomputer shuts down. In this way, the microcomputer shuts itself down after a predetermined time elapses in response to detecting that the device-side microcomputer of the electric device main body has shut down, so when there is no need to operate, the microcomputer shifts to the power saving mode. In addition, self-consumption of power by the battery pack microcomputer can be suppressed. Further, a power management circuit is provided for activating a power supply circuit for the microcomputer in response to a voltage change of the LD terminal, and the power management circuit activates the power supply circuit when a voltage is applied to the LD terminal. As a result, the microcomputer that has been shut down can be restarted in accordance with the operation of the electric device body. Further, the microcomputer is configured to shut down or sleep the microcomputer when the voltage of the LD terminal becomes zero due to, for example, removing the battery pack from the main body of the electric device.

According to the present invention, the power supply state of the electric device main body is detected on the battery pack side, and when the power supply of the microcomputer on the device side is turned on, the microcomputer on the battery pack side is also kept on. When the power of the microcomputer on the device side is turned off, it is detected and the microcomputer on the battery pack side also shifts to the power saving mode. Further, since a circuit of the battery pack is activated when a predetermined voltage is input to the LD terminal, there is no need to separately provide a dedicated connection terminal for activating the power supply circuit of the microcomputer on the battery pack side. The microcomputer on the battery pack side can be turned on / off according to the state of the device on the other side to which the battery pack is mounted using the LD terminal). Further, a state in which the battery pack is removed (device unconnected state) is detected from the voltage of the LD terminal, and when it is detected that the state has elapsed for a predetermined time, the power supply circuit of the microcomputer on the battery pack side is set to the power saving mode (sleep mode). (Or shutdown), so that the power consumption by the microcomputer when the battery pack is removed can be significantly reduced.

FIG. 3 is a view for explaining a state of attachment of the battery pack 100 according to the present invention to the power tool main body 1. FIG. 1 is a perspective view of a battery pack 100 according to an embodiment of the present invention. FIG. 2 is a circuit diagram showing a state in which the battery pack 100 according to the present embodiment is connected to the power tool main body 1 with a microcomputer. FIG. 4 is a circuit diagram showing a state in which the battery pack 100 of the present embodiment is connected to a power tool main body 1A without a microcomputer. 5 is a flowchart illustrating a control procedure in a normal mode of the battery pack 100 according to the embodiment. 5 is a flowchart illustrating a control procedure in a sleep mode of the battery pack 100 according to the embodiment. 5 is a flowchart for explaining an operation example 1 of the battery pack 100 of the embodiment. 6 is a flowchart for explaining an operation example 2 of the battery pack 100 of the embodiment. 9 is a flowchart for explaining an operation example 3 of the battery pack 100 of the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same portions are denoted by the same reference numerals, and repeated description will be omitted. In this specification, an electric tool that operates on a battery pack is described as an example of an electric device, and the front, rear, left, right, and up and down directions when viewed as a single battery pack are the mounting directions of the battery pack. The direction will be described with reference to FIG.

FIG. 1 is a diagram for explaining a state in which the battery pack according to the present embodiment is mounted on a power tool. An electric tool, which is one form of electric equipment, includes a battery pack 100 and drives a tool bit and a working device by using a rotational driving force of a motor. Although various types of electric tools are realized, the electric tool main body (electric device main body) 1 shown in FIG. 1 applies a rotational force or an axial impact force to a tip tool such as a bit or a socket wrench (not shown). This is an impact tool that performs tightening work. The tip tool is mounted on the tip tool holding unit 8. The power tool main body 1 includes a housing 2 which is an outer frame forming an outer shape, and a handle portion 3 is formed on the housing 2. A trigger-shaped operation switch 4 is provided near a part of the handle part 3 and hit by an index finger when the worker holds the battery pack 100, and a battery pack 100 is mounted below the handle part 3 of the housing 2. Battery pack mounting portion 10 is formed.

Inside the battery pack 100, one or more sets of cell units formed by connecting a plurality of lithium-ion battery cells having a rating of 3.6V are accommodated. A `` cell unit '' is one in which a plurality of battery cells are electrically connected, and as an example, a connected body in which a plurality of battery cells are connected in series, a connected body in which a plurality of battery cells are connected in parallel, and And a connected body in which a plurality of battery cells are connected in series and in parallel. Rail grooves (not shown) for mounting the battery pack 100 are formed in the battery pack mounting section 10, and input terminals for fitting with connection terminals of the battery pack 100 are formed. Rails 138a and 138b (see FIG. 2) are formed on the battery pack 100, and are locked by latches 141 (141a and 141b).

FIG. 2 is a perspective view of the battery pack 100 according to the embodiment of the present invention. The battery pack 100 can be attached to and detached from the battery pack mounting portion 10 (see FIG. 1), and corresponds to the terminal shape on the power tool main body 1 side. The housing of the battery pack 100 is formed by a lower case 101 and an upper case 110 that can be divided in the vertical direction. The lower case 101 and the upper case 110 are made of a member that does not conduct electricity, for example, a synthetic resin, and are fixed to each other by four screws (not shown). The upper case 110 has a mounting mechanism in which two rails 138a and 138b are formed for mounting on the battery pack mounting portion 10. The rails 138a and 138b are formed so that the longitudinal direction is parallel to the mounting direction of the battery pack 100 and protrude from the left and right side surfaces of the upper case 110 in the left and right direction. The front ends of the rails 138a and 138b are open ends, and the rear ends are closed ends connected to the front wall surface of the raised portion 132. The rails 138a and 138b are formed in a shape corresponding to a rail groove (not shown) formed in the battery pack mounting portion 10 of the power tool main body 1. When the rails 138a and 138b are fitted with the rail grooves, the rails 138a and 138b The battery pack 100 is fixed to the power tool main body 1 by being locked by the locking portions 142a (see FIG. 1) and 142b. When the battery pack 100 is removed from the power tool body 1, the latches 142a and 142b are moved inward by releasing the latches 141 (141a and 141b) on the left and right sides to release the locked state. In this state, the battery pack 100 is moved to the opposite side to the mounting direction.

A flat lower step surface 111 is formed on the front side of the upper case 110, and an upper step surface 115 that is formed higher than the lower step surface 111 is formed near the center. The lower step surface 111 and the upper step surface 115 are formed in a step shape, and a connection portion thereof is a step portion 114 which is a vertical surface. The front side portion of the upper step surface 115 from the step portion 114 is an area where the slots 121 to 128 are arranged. Each of the slots 121 to 128 is a portion cut out to have a predetermined length in the battery pack mounting direction so as to extend rearward from the front step portion 114, and inside the cutout portion. A plurality of connection terminals (not shown) that can be fitted to the device side terminals of the power tool main body 1 or an external charging device (not shown) are provided. In the slots 121 to 128 of this embodiment, notches are respectively formed on the upper surface and the vertical surface parallel to the mounting direction so that the terminal on the power tool main body side can be inserted from the lower step surface 111 side. An opening 113 is formed below the slots 121 to 128 and continuously with the lower surface 111 between the lower surface 111 and the slot.

Of the slots 121 to 128, the slot 121 on the right side of the rail 138 a on the right side of the battery pack 100 serves as an insertion port for a positive terminal for charging (C + terminal), and the slot 122 serves as an insertion port for a positive terminal for discharging (+ terminal). Become. In addition, the slot 127 on the side close to the left rail 138b of the battery pack 100 serves as an insertion port for the negative terminal (-terminal). In the battery pack 100, the positive electrode side and the negative electrode side of the power terminal for transmitting power are usually arranged so as to be sufficiently separated from each other. A terminal (+ terminal) is provided, and a negative electrode terminal is provided at a position far apart on the left side. Between the positive terminal and the negative terminal, a plurality of signal terminals for transmitting signals used for controlling the battery pack 100, the power tool body 1, and an external charging device (not shown) are arranged. Are provided between the power terminals. The slot 123 is a spare terminal insertion port, and no terminal is provided in this embodiment. The slot 124 is an insertion port for a T terminal for outputting a signal serving as identification information of the battery pack 100 to the power tool main body or the charging device. The slot 125 is an insertion port for a V terminal for inputting a control signal from an external charging device (not shown). The slot 126 is an insertion port for an LS terminal for outputting battery temperature information by a thermistor (temperature sensing element) (not shown) provided in contact with the cell. A slot 128 for an LD terminal for outputting an abnormal stop signal by a battery protection circuit described later included in the battery pack 100 is further provided on the left side of the slot 127 serving as an insertion port of the negative terminal (− terminal).

On the rear side of the upper step surface 115, a raised portion 132 formed to be raised is formed. The raised portion 132 has a shape in which its outer shape is raised above the upper step surface 115, and a recessed stopper portion 131 is formed near the center thereof. The stopper portion 131 is a surface which is abutted against a protrusion (not shown) of the battery pack mounting portion 10 when the battery pack 100 is mounted on the battery pack mounting portion 10. When the protruding portion relatively moves to a position where it comes into contact with the stopper portion 131, a plurality of terminals (device-side terminals) provided on the power tool main body 1 and a plurality of connection terminals provided on the battery pack 100 (see FIG. (To be described later) comes into contact with each other and becomes conductive. At the same time, the engaging portions 142a (see FIG. 1) and 142b of the latch 141 of the battery pack 100 protrude left and right below the rails 138a and 138b by the action of a spring, and are formed in the rail grooves of the power tool body 1. Engagement with the concave portion prevents the battery pack 100 from falling off.

Next, a circuit configuration in a state where the battery pack 100 of the embodiment is connected to the power tool main body 1 with a microcomputer will be described with reference to FIG. In the circuit diagram of FIG. 3, a left area surrounded by a dotted line is a schematic block diagram illustrating an internal configuration of the electric power tool main body 1, and a right part is an internal configuration of the battery pack 100. On the battery pack 100 side, a positive terminal 162 and a negative terminal 167 are provided as terminals for power output. A corresponding positive power input terminal 22 and negative power input terminal 27 are provided on the corresponding power tool body 1 side. The battery pack 100 is further provided with four signal transmission terminals (signal terminals), but only the LD terminal 168 is used for connection to the power tool main body 1 side. Therefore, FIG. 3 shows only a circuit related to the LD terminal 168 as a signal transmission terminal on the battery pack 100 side, and shows an output circuit for other signal transmission terminals (V terminal, LS terminal, T terminal). Is omitted. Note that use of the terminal other than the LD terminal 168 is not excluded. For example, when connecting to an external charging device, all other signal terminals of the battery pack 100 are connected.

The power tool main body 1 is provided with a DC motor 5 in a power supply path between the positive input terminal 22 and the negative input terminal 27, and operates the work equipment using the rotational driving force of the motor 5 to tighten the screw. Perform predetermined work such as. In the power supply path, a trigger switch 4 for turning on or off the rotation of the motor 5 is provided in series. When the operator operates the lever of the trigger switch 4, the trigger switch 4 is turned on, and the electric power from the battery pack 100 is supplied to the motor 5. Further, when the operator releases the operation of the lever of the trigger switch 4, the trigger switch 4 is turned off, and the power supply to the motor 5 is cut off. The power tool main body 1 is provided with a control unit 60 for detecting a current value flowing to the motor 5 and protecting the motor 5 and the driving mechanism. The control unit 60 includes a microcomputer 60a. A semiconductor switching element M21 and a shunt resistor R21 are inserted between the motor 5 and the negative input terminal 27. The switching element M21 is, for example, an FET (field effect transistor), and its gate signal 66 is transmitted by the control unit 60. Normally, a high signal is output as the gate signal 66 of the switching element M21, and the motor 5 and the negative input terminal 27 are brought into conduction. On the other hand, when the rotation of the motor 5 is stopped for some reason such as when the microcomputer 60a detects an abnormal state, the gate signal 66 is switched from high to low to shut off the source-drain of the switching element M21. . By thus interposing the switching element M21 in the power supply path, the microcomputer 60a on the device side can control the motor 5 to stop.

The current detection circuit 64 is provided for measuring the value of the current flowing through the motor 5, and measures the voltage across the shunt resistor R 21 to generate a signal proportional to the value of the current flowing through the shunt resistor R 21. Output to The control unit 60 monitors the current value in real time using the output of the current detection circuit 64, so that when an excessive load is applied to the motor 5 or an excessive current occurs when the motor is locked, the gate is controlled. When the signal 66 is set to low, the motor 5 is stopped to protect the motor 5 and also protect a mechanism such as a power transmission mechanism. After the motor 5 is stopped, the operator removes the cause of the excessive current, removes the tip tool from the fixed screw or bolt, and turns on the trigger switch 4 again to start the motor. After the control unit 60 sets the gate signal 66 to low, it detects that the trigger switch 4 has been turned off and returns the gate signal 66 to high, so that the operator can resume work.

The control unit 60 including the microcomputer 60a operates with a low-voltage power supply generated by the power supply circuit 61. The power supply circuit 61 generates a power supply for operation of the control unit 60, and generates a low drive voltage (a reference voltage VDD2, for example, 5 V) from a direct current (for example, a rated voltage of 18 V) supplied from the battery pack 100 side. To the control unit 60. Therefore, when the battery pack 100 is detached from the power tool main body 1, power from the power supply circuit 61 cannot be obtained, and the microcomputer 60a is in a stopped state. On the other hand, when the battery pack 100 is mounted on the power tool main body 1, the preparation for starting supply of the reference voltage from the power supply circuit 61 to the control unit 60 is completed. The power supply management circuit 62 is an electric circuit for instructing or suppressing the generation of the reference voltage VDD2 by the power supply circuit 61. The power supply management circuit 62 has one end connected to the power supply circuit 61, the other end grounded (not shown), a potential between the trigger 4 and the motor 5 as a first input signal, and a second input. A signal from the microcomputer 60a, that is, a self-holding signal 62a is input as a signal. The power supply management circuit 62 activates the power supply circuit 61 when one or both of the input signals become high, and controls the reference voltage VDD2 to be supplied from the power supply circuit 61 to the control unit 60. When both of the input signals become low, the power management circuit 62 stops the power supply to the control unit 60 by stopping the power supply circuit 61. When the supply of the reference voltage VDD2 to the control unit 60 stops, the microcomputer 60a shuts down.

The battery voltage detection circuit 65 is a circuit that measures a voltage between the positive input terminal 22 and the negative input terminal 27 and outputs the voltage to the control unit 60. By using the battery voltage detection circuit 65, the control unit 60 can monitor the battery voltage in real time. When the voltage from the battery pack 100 falls to or below a predetermined reference value, the control unit 60 determines that the battery cell is in an overdischarged state, and changes the gate signal 66 from high to low to change the motor 5. Stop the operation of. The switch state detection circuit 63 outputs a high or low signal to the control unit 60 according to the connection state of the trigger switch 34. The microcomputer 60a can detect the operating state (use state) and the stopped state (non-use state) of the power tool by the output of the switch state detection circuit 63, and the non-use state continues for a predetermined time or more. In this case, the supply of the reference voltage VDD2 to the microcomputer 60a is stopped to shift the microcomputer 60a to the power saving mode. Here, as the power saving mode, shifting the operation mode of the microcomputer 60a to the sleep mode and shutting down the microcomputer 60a itself can be considered. The shutdown can be easily executed by the microcomputer 60a switching the self-holding signal 62a from high to low. For example, when the power tool body 1 is an impact driver, the microcomputer 60a is turned off for several minutes to several hours after the detection of the last trigger operation by the switch state detection circuit 63 without any trigger operation. Shut down. When the trigger switch 4 is operated by the operator after the microcomputer 60a is shut down and the trigger switch 4 is turned on, a potential (high signal) between the trigger 4 and the motor 5 is input to the power management circuit 62. Therefore, the power supply circuit 61 is activated and the reference voltage VDD2 is supplied to the microcomputer 60a. Therefore, the microcomputer 60a starts immediately in conjunction with the trigger operation, and operates in the normal operation mode (normal mode).

The LD terminal 28 of the power tool body 1 is connected to an input port of the microcomputer 60a. Normally, a reference voltage VDD2 is connected to the LD terminal 28 via a resistor R22. With this configuration, a voltage substantially equal to the reference voltage VDD2 (基準 5 V) is applied to the input port of the control unit 60 and the LD terminal 28 in a normal state. The input port of the microcomputer 60a connected to the LD terminal 28 also becomes high. On the other hand, when the LD terminal 168 on the battery pack 100 side connected to the LD terminal 28 is grounded as described later and the potential of the LD terminal 28 drops to the ground level, the input port of the microcomputer 60a changes from high to low. Therefore, the microcomputer 60a can receive the discharge stop signal (or emergency stop signal) from the battery pack 100 by detecting the change in the potential of the LD signal line 67. When the LD signal line 67 becomes low, the microcomputer 60a switches the gate signal 66 of the switching element M21 to low, and stops the power supply to the motor 5. Although the motor 5 is illustrated as a DC motor with a brush in the circuit of FIG. 3, a configuration in which a three-phase brushless motor is driven using a known inverter circuit may be used. In that case, the switching element M21 may be connected in series in a power path input to an inverter circuit (not shown), or the motor may be controlled by controlling a switching element (not shown) included in the inverter circuit instead of the switching element M21. 5 may be stopped.

Battery pack 100 includes a positive terminal 162, a negative terminal 167, and an LD terminal 168. The positive terminal (162) of the cell unit 146 is connected to the positive terminal (162), and the negative terminal (167) of the cell unit 146 is connected to the negative terminal (167). The cell unit 146 is formed by connecting five lithium-ion battery cells 146a to 146e in series. The battery unit protection circuit 220 for monitoring the voltage of the battery cell is connected to the cell unit 146. The battery cell protection circuit 220 is an integrated circuit that is commercially available as a so-called “lithium ion battery protection IC”. By inputting the voltage between both ends of each battery cell of the cell unit 146, the voltage of each of the battery cells 146a to 146e is input. And performs any of a cell balance function, a cascade connection function, a disconnection detection function, and the like in addition to an overcharge protection function and an overdischarge protection function using the detected voltage.

The LD terminal 168 is a terminal for transmitting a signal from the battery pack 100 to stop the power tool main body 1 or a signal to stop operation of an electric device powered by a battery pack (not shown). A discharge prohibition control circuit 240 is provided to change the state of LD terminal 168. The discharge prohibition control circuit 240 determines that the discharge prohibition signal 241 is low (discharge is permitted) during normal operation, but the microcomputer 250a determines that it is necessary to stop the discharge from the battery pack 100. , The over-current state, and the over-temperature state, the discharge inhibition signal 241 is switched to high (discharge inhibition). The drain of the switching element M1 using the FET is connected to the LD terminal 168. The switching element M1 is, for example, a P-type field effect transistor (FET). The drain side is connected to the LD terminal 168, and the source side is grounded. A resistor R2 and a capacitor C1 are provided between the gate and the source. The resistor R2 is a ground resistor for setting the voltage between the gate and the source to 0 V when the gate signal becomes low. The capacitor C1 is provided to slightly delay the rise in the potential of the LD terminal 168 when the discharge inhibition signal 241 changes from high to low. The resistor R5 is a resistor for stabilizing the voltage of the LD terminal 168. The control unit 250 changes the gate signal (discharge inhibition signal 241) input to the semiconductor switching element M1 of the discharge inhibition control circuit 240 from the normal low state ("discharge permission" from the battery pack 100) to the high state (battery pack). 100 to “discharge inhibition”). When the discharge inhibition signal 241 is switched to high, the source and the drain of the switching element M1 are grounded by conduction, so that the potential of the LD terminal 28 on the power tool main body 1 side drops to the ground potential. As a result, the power circuit of the power tool main body 1 is cut off by the microcomputer 60a, and the rotation of the motor 5 is stopped. As described above, since the rotation of the motor 5 of the power tool body 1 can be prevented by the discharge prohibition signal 241 generated by the control unit 250 of the battery pack 100, the control unit 250 must stop the power supply from the battery pack 100. For example, when an excessive current during discharge, a decrease in cell voltage during discharge (overdischarge), an abnormal rise in cell temperature (overtemperature), or the like, the operation of the power tool or the electric device can be stopped quickly. Thus, not only the battery pack 100 but also the power tool body 1 can be protected.

The control unit 250 is connected to the battery cell protection circuit 220. The control unit 250 includes a microcomputer 250a. The power supply for driving the control unit 250 is generated by the power supply circuit 221, and a low constant voltage (reference voltage VDD1) is supplied to the control unit 250. Here, the reference voltage VDD1 for operating the control unit 250 is 3.3V. The control unit 250 monitors the voltage value, the current value and the cell temperature, and transmits a discharge prohibition signal 241 to the other device, that is, the power tool body 1 based on the output of the battery cell protection circuit 220. The microcomputer 250a determines from the output of the terminal voltage detection circuit 228 that measures the voltage value of the LD terminal 168, whether the microcomputer 60a is included in the other device. The normal voltage transmitted from the LD terminal 28 to the LD terminal 168 is the operating voltage (ａ3.3 V or 5 V) of the microcomputer 60 a when the other device includes the microcomputer 60 a, but does not include the microcomputer. In the case of equipment, the voltage is the battery pack voltage VCC (18 V in this case). By detecting the voltage difference, the microcomputer 250a can switch control parameters for overcurrent monitoring and temperature monitoring.

The power management circuit 222 is a circuit for instructing or suppressing generation of the reference voltage VDD1 by the power circuit 221. The power management circuit 222 has one end connected to the power supply circuit 221 and the other end grounded (not shown). Also, the potential of the LD terminal 168 is input as the power supply start signal 223 as the first input signal, and a signal from the microcomputer 250a, that is, the self-holding signal 224 is input as the second input signal. When the battery pack 100 is not attached to the partner device, that is, when the battery pack 100 is removed, the LD terminal 168 is in a high impedance state, and the potential of the power supply start signal 223 is low. The power management circuit 222 activates the power circuit 221 when one or both of the input signals (the power activation signal 223 and the self-hold signal 224) become high, and supplies the reference voltage VDD1 from the power circuit 221 to the control unit 250. To do. When both of the input signals become low, the power supply management circuit 222 stops sending the reference voltage VDD1 from the power supply circuit 221 to cut off the power supply to the control unit 25, so that the microcomputer 250a shuts down. . When the trigger switch 4 is operated after the battery pack 100 is mounted on the power tool body 1, the terminal voltage of the LD terminal 168 (= power activation signal 223) rises from 0V to the reference voltage VDD2 (here, about 5V). I do. As a result, the power management circuit 222 activates the power circuit 221 in conjunction with the activation of the microcomputer 60a on the power tool main body 1 body side, and the reference voltage VDD1 is supplied to the control unit 250, so that the microcomputer 250a is also activated. I do. In this way, the microcomputer 250a of the battery pack 100 is activated in conjunction with the microcomputer 250a on the power tool main body 1 side.

When an emergency stop of the power tool main body 1 becomes necessary, the microcomputer 250a issues a discharge prohibition signal 241 to change the potential of the LD terminal 168, so that the microcomputer 250a sends the power tool main body 1 via the LD terminal 28. Instructs the operation to stop. Further, the control unit 250 monitors the amount of current flowing through the battery cells of the cell unit 146. In recent power tools, it has become possible to take out a large current from the battery pack 100 with the improvement of the performance and capacity of the battery cells. However, from the viewpoint of life and heat generation, it is preferable that the battery cell is limited to a predetermined current amount (current upper limit value or less). When the microcomputer 60a is included in the power tool main body 1, the microcomputer 60a can monitor the overcurrent. Therefore, the microcomputer 250a may have a high threshold value for preventing the battery pack 100 from being damaged. However, if the power tool body 1 does not include the microcomputer 60a, there is a high possibility that the power tool body 1 has not performed overcurrent monitoring, and the microcomputer 250a has a general overcurrent monitoring threshold value. When the discharge current from the battery pack 100 exceeds 20 A, the microcomputer 250 a sets the discharge prohibition signal 241 to high. Similarly, the microcomputer 250a also performs overdischarge management of the cell unit 146. If the voltage of the battery cell of the cell unit 146 drops below a predetermined threshold value V _1, the microcomputer 250a by issuing a discharge inhibiting signal 241 to prohibit discharge stops the operation of the power tool main body 1 side.

The control unit 250 monitors the current value using the shunt resistor R1 and the current detection circuit 227 interposed in the middle of the power supply line of the battery cell protection circuit 220 in order to particularly monitor the current flowing through the battery cell. The current detection circuit 227 is a circuit for measuring the value of the current flowing through the cell unit 146 by measuring the voltage of the shunt resistor R1 interposed in series with the cell unit 146. The output of the current detection circuit 227 is controlled by the control unit 250. Of the microcomputer 250a. The microcomputer 250a includes, for example, a voltage detection circuit called an analog front end (AFE), and measures a current value flowing through the battery cell protection circuit 220 from an output voltage of the current detection circuit 227. The battery cell protection circuit 220 including the control unit 250, the power supply circuit 221, the current detection circuit 227, and the like may be configured as a "battery management IC" integrated in one chip. The battery cell protection circuit 220 is connected to the control unit by a plurality of signal lines, and the microcomputer 250a can detect the voltage of each of the battery cells 146a to 146e. The cell temperature detecting means 231 is a circuit for measuring the temperature of the battery cell using a thermistor (not shown) provided near the battery cells 146a to 146e.

When the power supply of the power supply circuit 221 is turned on, the power supply voltage VDD1 is supplied to the control unit 250, so that the microcomputer of the power supply circuit 221 starts. When the microcomputer 250a is started, the self-holding signal 224 from the microcomputer 250a changes from low to high and is input to the power management circuit 222, so that the state in which the microcomputer 250a is started is maintained. On the other hand, when the power supply from the power supply circuit 221 to the control unit 250 stops, the microcomputer 250a shuts down. The shutdown of the microcomputer 250a is performed by stopping the output of the power supply circuit 221 by switching the self-holding signal 224 from high to low when the power activation signal 223 is in the low state.

When the control unit 250 including the microcomputer is provided in the battery pack 100, the state where the power supply voltage VDD1 can be supplied to the control unit 250 continues unless the voltage of the cell unit 146 is sufficiently reduced. Therefore, in the battery pack 100, when it is not necessary, particularly when the battery pack 100 is detached from the electric device main body or the external charging device, or when the electric device main body or the external charging device attached to them is in a stopped state. In any of the cases, when the battery management control necessary for the control unit 250 is not performed (or unnecessary), the power supply to the control unit 250 is shut off so that the battery cell Self-consumption of electricity.

When the microcomputer 250a is shut down after the LD terminal 168 is dropped to the ground level, the discharge prohibition signal 241 disappears. Therefore, the LD terminal 168 becomes high again, the power management circuit 222 operates, and the microcomputer 250a starts. There is a possibility that such an operation that the discharge prohibition signal 241 is transmitted again may be repeated. Therefore, in this embodiment, the shutdown maintaining circuit 260 is provided so that the power supply circuit 221 cannot be restarted after the discharge prohibition signal 241 is transmitted due to the overdischarge of the battery cells 146a to 146e. To prevent the power supply circuit 221 from being restarted, the LD terminal 168 may be kept at the ground potential. The shutdown maintaining circuit 260 includes two switching elements M2 and M3 such as FETs, a plurality of resistors (resistors R3 and R4), a diode D1, and a zener diode ZD1. The basic operation, keeping the case where the battery voltage VCC of the cell unit 146 is threshold V ₁ or a cutoff state switching device M2, the battery voltage VCC switching element When becomes less than the threshold value V ₁ showing the over-discharge state M2 Are kept in the connected state, so that the potential of the LD terminal 168 is maintained at the ground level. The drain terminal of the switching element M2 is connected to the LD terminal 168, and the source terminal is grounded. The drain terminal of the further switching element M3 is connected to the gate signal of the switching element M2. The battery voltage VCC of the cell unit 146 is connected to the drain terminal of the switching element M3 via the resistor R3. The source terminal of the switching element M3 is grounded, and the gate terminal receives the voltage divided by the Zener diode ZD1 and the resistor R4 between the battery voltage VCC and the ground. The shutdown maintenance circuit 260, the voltage VCC of the battery pack becomes smaller than the threshold value _{V 1} of the over-discharge, and, when the supply of VDD1 to via a diode D1 is eliminated, LD terminal switching devices M3, M2 are both turned on 168 is dropped to the ground potential. ON state of the switching element M2 is sufficiently operate at lower voltage range than the threshold value V ₁ is the battery voltage VCC. Therefore, the ON state of the switching element M2 is maintained until the battery voltage VCC decreases to a voltage value V ₀ (V ₀ > 0) much smaller than V ₁ . With this configuration, it is possible to prevent the occurrence of a chattering phenomenon in which the microcomputer 250a is repeatedly restarted after the microcomputer 250a is shut down due to overdischarge. Deep discharge of the cells 146a to 146e can be prevented.

The state of the microcomputer 250a has three stages: normal, sleep, and shutdown. Normal is a state in which the microcomputer 250a is always running. The sleep mode is a power saving mode in which the microcomputer 250a intermittently activates itself, and repeats an operation of stopping for several hundred milliseconds after starting for several milliseconds. Shutdown is a power saving mode in which the power supply voltage VDD1 is not supplied at all, and is a state in which the microcomputer 250a is completely stopped. The microcomputer 250a operates both when the battery pack 100 is mounted on the power tool main body 1 and when it is not mounted. However, when the battery pack 100 is not mounted, or when the power tool has not been used for a certain period of time even when the battery pack 100 is mounted, for example, the trigger operation has not been performed for about 2 hours after the trigger operation has been completed. In this case, the microcomputer 250a enters a sleep state. Even in the sleep state, when the state of the LD terminal 28 changes, the power supply management circuit 222 turns on the power supply circuit 221 and the microcomputer 250a returns to the normal mode. With this configuration, the operation of the microcomputer 250a in the normal mode and the operation (or stop) in the other power saving modes can be controlled in conjunction with the microcomputer 60a of the power tool body 1.

FIG. 4 is a circuit diagram showing a state in which the battery pack 100 of this embodiment is connected to the power tool body 1A without a microcomputer. The power tool main body 1A is configured to include a positive input terminal 22, a negative input terminal 27, and an LD terminal 28 on the device side. The trigger switch 4 and the DC motor 5 are connected between the positive input terminal 22 and the negative input terminal 27. A switching element M31 made of a semiconductor is provided between the motor 5 and the negative input terminal 27. The drain-source of the switching element M31 is connected to the power supply path of the motor 5, and the gate is connected to the positive input terminal 22 via the resistor R31. The gate of the switching element M31 is connected to the LD terminal 28 via the resistor R32. Normally, the LD terminal 28 on the battery pack 100 side is in a high impedance state. At that time, a positive voltage is applied to the gate of the switching element M31 via the resistor R31, and the switching element M31 is in a conductive state. At this time, when the LD terminal 168 is dropped to the ground potential by the discharge inhibition signal 241 from the battery pack 100 side, the gate potential of the switching element M31 becomes a voltage obtained by dividing the voltage of the positive input terminal 22 by the resistors R31 and R32. This divided potential becomes a potential that cuts off between the source and the drain of the switching element M31. As a result, the power supply path to the motor 5 is cut off, and the rotation of the motor 5 stops. This switching of the potential of the LD terminal 168 is performed by the discharge prohibition control circuit 240 under the control of the microcomputer 250a on the battery pack 100 side, and the voltage of the battery cell drops to the threshold value (predetermined voltage value V ₁ ) of the overdischarge state. This is executed when the battery cell is in a state of over-discharge, when the current flowing through the battery cell exceeds a specified upper limit, when the temperature of the battery cell exceeds the upper limit, or the like.

When the control unit 250 of the battery pack 100 monitors overcurrent as in the power tool body 1A, an average overcurrent protection control that can be applied to the plurality of power tool bodies 1A is required. In this case, the threshold current IC for determining an overcurrent must be set to an average value. However, when the control unit 60 of the power tool main body 1 monitors the overcurrent, the control unit 250 can set an optimal control condition (a threshold for increasing the overcurrent) to the power tool main body 1, so that the control unit 250 performs the average control. It is possible to avoid the output limitation of the power tool by setting an appropriate control condition (lower threshold value of overcurrent). The avoidance of the output limitation is particularly effective for a new electric power tool to be released in the future, and it is possible to realize a control that makes full use of the capability of the new electric power tool main body 1.

In the present embodiment, the control unit 250 of the battery pack 100 determines whether or not the power tool main body 1 or 1A side on which the battery pack 100 is mounted includes the control unit 60 having a microcomputer. Then, the condition for overload protection on the battery pack 100 side is changed. Specifically, when a microcomputer is not included in the power tool body 1 as shown in FIG. 4, the overcurrent limit value at the time of low voltage output is set to a threshold value for the power tool body 1A without a microcomputer, for example, 20A (default value). Set to. The default value may be appropriately set according to the capacity and performance of the battery cell used. Since this overcurrent limit value is made equal to the value set in the conventional battery pack, the conventional power tool body without microcomputer 1A can be driven using the battery pack 100 of the present embodiment. On the other hand, when the microcomputer is included in the power tool body 1A, the overcurrent limit value at the time of low voltage output is not set on the battery pack 100 side, or even if it is set, it is sufficiently higher than the power tool body 1 without the microcomputer. As the threshold value (for example, the threshold value of the overdischarge is 50A), the monitoring of the overcurrent value is left to the microcomputer of the control unit 60 on the power tool main body 1A side.

The terminal voltage detection circuit 228 is connected to the LD terminal 168 by a connection line, and the terminal voltage detection circuit 228 outputs an output corresponding to the terminal voltage to the control unit 250. This operation is the same as that of the circuit shown in FIG. The control parameters for monitoring the battery cell, such as the overload protection conditions, which are changed by the control unit 250 determining the presence or absence of the microcomputer on the power tool main body 1A side by the terminal voltage detection circuit 228 are the nonvolatile parameters included in the microcomputer 250a. What is necessary is just to store in advance in the memory and read and set one of the stored values according to the determination result.

Next, a control procedure in the normal mode of the battery pack 100 of this embodiment will be described with reference to FIG. The microcomputer of the control unit 250 of the battery pack 100 has three operation levels: normal mode, sleep mode, and shutdown. The normal mode is a state in which the microcomputer is continuously activated, and the sleep mode is a mode in which the microcomputer is activated intermittently to save operating power. The shutdown mode is a mode in which the operation of the microcomputer included in the control unit 250 is stopped by cutting off the power supply from the power supply circuit 211 to the control unit 250. Figure 5 is a control state in which the microcomputer is operating in the normal mode (step 300), first whether the microcomputer is battery voltage using the battery cell protection circuit 220 is a predetermined threshold value V ₂ less A determination is made (step 301). Threshold V ₂ is the threshold value for monitoring the overcharged state of the battery cell, if it exceeds the threshold value V ₂ returns to step 301 to clear the timer A and timer B (step 308). If YES in step 301, the microcomputer determines that the charge current by using the current detection circuit 227 is equal to or less than the threshold value _{I C} (step 302). Threshold I _C is the upper limit of the normal charging current range. In the case where the charging current is below the threshold value I _C, the process proceeds to step 303, if it exceeds the threshold value I _C returns to step 301 to clear the timer A and timer B (step 308). If this is the charging current is not less than the threshold value I _C, it must send the charging stop signal by using the LS terminal (not shown) to an external charging device (not shown). Therefore, the microcomputer 250a is maintained in the normal mode. Note that the flowchart of FIG. 3 only shows the transition of the operation mode of the microcomputer 250a, and a charge management program (not shown) is executed in parallel with the flowchart of FIG.

In step 303, it is determined whether the discharge current is below the threshold value I ₁ serving limit acceptable. Here the process proceeds to step 304 if the threshold value _{I 1} or less, if it exceeds the threshold value _{I 1} returns to step 301 to clear the timer A and timer B (step 308). In step 304, the microcomputer determines whether or not more than thresholds T ₁ serving limit acceptable battery temperature, when the thresholds T ₁ or less, if i.e. the normal state proceeds to step 305, exceeds the thresholds T ₁ In this case, the microcomputer 250a maintains the normal mode by clearing the timer A and the timer B (step 308) and proceeding to step 301. At this time, what kind of battery management control is performed according to the battery temperature is managed by a program (not shown) different from FIG.

In step 305, the microcomputer measures the voltage of the LD terminal 168 from the output of the terminal voltage detection circuit 228, and determines whether the LD terminal voltage is in a low state (step 305). When the LD terminal voltage is low, it means that the microcomputer is included in the connected external device (electric device main body or charging device). In this case, the shutdown transition process using the timer A is performed. Execute. First, increments the count of the timer A, it determines whether the count value of the timer A is equal to or greater than the threshold value N _A (step 307). In step 307, if it is less than the threshold value _{N A} returns to step 301, if less than the threshold value _{N A,} performs shutdown processing of the microcomputer 250a of the control unit 250 (step 309). In this manner, when a state of not being the use of a certain time only the battery pack 100 to the timer A reaches the threshold N _A is followed, it is automatically shut down microcomputer 250a of the battery pack 100 side it can.

In step 305, if the LD terminal voltage is high, it means that the connected external device (electric device main body or charging device) does not include a microcomputer. The microcomputer on the battery pack 100 side is shut down in conjunction with this, and the microcomputer on the battery pack 100 side cannot be started in conjunction with the activation of the microcomputer on the external device side. Therefore, the control for shifting the microcomputer 250a to the power saving mode is spontaneously performed on the battery pack 100 side without interlocking with the power tool main body 1A side. That is, in step 310, the sleep mode transition processing is executed using the timer B. First, the count of the timer B is incremented (step 310). Next, it is determined the count value of the timer B is a predetermined time value for shifting to the sleep mode, whether words or equal to or greater than the threshold value N _B (Step 311). If the count value is less than the threshold value N _B returns to step 301, if the count value is not less than the threshold value N _B, performs the migration processing of the timer B of the control unit 250 after clearing to zero the microcomputer sleep mode (step 312, 313). Since the procedure after the microcomputer is switched to the sleep mode is known, the description thereof is omitted. In this manner, when the counterpart device does not include a microcomputer in the body, once only followed nonuse state of the battery pack 100 a certain time until the timer A reaches the threshold N _B, the battery pack 100 side The microcomputer is automatically shifted to sleep mode. By this shift, power consumption by the microcomputer in the battery pack 100 can be suppressed.

FIG. 6 is a flowchart showing control in a state where the microcomputer is operating in the sleep mode (step 350). First battery pack 100 side of the microcomputer determines whether the battery voltage is the threshold value V ₁ above using the battery cell protection circuit 220 (step 351). Threshold V ₁ was, in the same manner as described in FIG. 5, a threshold value for monitoring the over-discharge state of the battery cell, a normal to higher than the threshold value V ₁ is, in the case of less than the threshold value V ₁ external charging An overdischarge state that must be charged using the device. Therefore, if less than the threshold value V ₁ was sends a discharge inhibition signal 241 to determine whether or not over-discharged battery protection routine in the normal mode shifts to the normal mode proceeds to step 362 again. When the discharge prohibition signal 241 is transmitted, the power supply shutdown condition when returning to the flowchart of FIG. 5, that is, the LD terminal voltage = Low in step 305 is satisfied because the LD terminal 168 falls to the ground potential. microcomputer 250a after the lapse of N _a will be shut down. If the voltage of the voltage higher than the threshold _{V 1} at step 351 proceeds to step 352.

In step 352, the microcomputer 250a determines whether the battery voltage is the threshold value _{V 2} below using the battery cell protection circuit 220. Threshold V ₂ is a threshold voltage indicative of the abnormally high voltage, if a certain threshold value V ₂ or more because an abnormal value improbable normal or overcharged state, rather than intermittent control as sleep mode, continuous Then, the process proceeds to step 362 so that the control is shifted to the normal mode (step 352). In the normal mode, an abnormal countermeasure process (not shown) corresponding to the overvoltage is performed in the battery protection routine. Because if it is less than the threshold value V ₂ it is normal proceeds to step 353.

The microcomputer at step 353, determines whether the charging current is below the threshold value _{I C} using a current detection circuit 227 (step 353). Here, since if the charging current exceeds the threshold value I _C is an abnormal value, rather than intermittent control as the sleep mode, the normal mode proceeds to step 362 to allow continuous control Migrate. If the charging current is below the threshold value _{I C} at step 353 proceeds to step 354. The microcomputer at step 354 determines that the discharge current by using the current detection circuit 227 is the threshold value _{I 1} or less (step 353). Here, since the discharge current is greater than the threshold value I ₁ is high risk of overheating and the battery cell deterioration, by shifting to the normal mode proceeds to step 362, the overcurrent protection process defined (not shown) is performed It can be so. If discharge current threshold _{I 1} below proceeds to step 355.

In step 355 the microcomputer, with a cell temperature detection means 231 (see FIG. 3) to determine the temperature of the battery cell is thresholds T ₁ below, the step 356 because if the thresholds T ₁ below normal move on. During abnormal state where the temperature of the battery cell exceeds the thresholds T ₁ shifts to the normal mode proceeds to step 362. In step 356, the microcomputer 250a measures the voltage of the LD terminal 168 using the terminal voltage detection circuit 228 (see FIG. 3) to determine whether the battery pack 100 has been removed from the other device (power tool body or charging device). Determine whether When connected to the power tool body 1A without a microcomputer, the voltage of the LD terminal 168 is high, and when the battery pack 100 is removed, the voltage of the LD terminal 28 becomes low. If the battery pack 100 is removed in step 356, the process proceeds to step 362, where the microcomputer 250a on the battery pack 100 side shifts to the normal mode. When the battery pack 100 is not removed, the voltage of the LD terminal 28 remains high, but the connected external device does not include a microcomputer. Since it cannot be linked with the microcomputer on the side, the sleep setting is performed independently on the microcomputer 250a side (step 357). The sleep setting is control for reducing power consumption by cutting off power to most of the circuits of the microcomputer 250a. During the sleep setting, when a wake-up trigger signal is input to the microcomputer, the sleep state is changed to the active state (step 361), and the flow shifts to step 362 to shift to the normal mode. Here, the wake-up trigger signal refers to a state in which the trigger switch 4 on the power tool main body 1 side is pulled so that the discharge current rises to a predetermined value I _min or more, or the battery pack 100 is removed. A case where a switch (not shown) for displaying the remaining battery level is turned on may be considered. If no wake-up trigger is detected in step 358, it is determined whether or not a predetermined time has elapsed for the microcomputer to return from the sleep state to the active state (step 359). If it has elapsed, the microcomputer is returned to the active state. (Step 360), and the process returns to Step 351. If the predetermined time has not elapsed in step 359, the process returns to step 358.

As described above, the microcomputer 250a included in the control unit 250 of the battery pack 100 sets the sleep mode of the microcomputer 250a or sets the sleep mode of the microcomputer 250a depending on whether the connected external device includes the microcomputer 60a. It is possible to switch between shutdown and normal mode control without using it. In the flowchart of FIG. 6, the microcomputer 250a in the sleep mode does not shut down as long as the battery pack 100 is mounted on the power tool main body 1A. Therefore, by counting the continuous operation time T _S of the sleep mode of the microcomputer 250a, the predetermined threshold continuous operation time T _S, the microcomputer 250a may be controlled so as to shut down if, for example was a 1 week. 6 does not result in a shutdown, but a combination of FIGS. 6 and 5 causes a shutdown. Operation becomes either voltage V ₂ or less when continues the sleep mode in Fig. Then, the mode shifts to the normal mode. 7, the microcomputer 250a outputs a discharge prohibition signal 241 and the LD terminal 168 goes low when the mode is shifted to the normal mode in FIG. When the timer A becomes equal to or more than the predetermined value, the microcomputer 250a shuts down.

FIG. 7 is a diagram for explaining a control procedure of an operation example 1 of the battery pack 100 of the present embodiment, and is a flowchart showing an operation example 1 for the power tool main body 1 in which the control unit 60 on the main body side also includes a microcomputer. . This flowchart is started when an operator attaches the battery pack 100 to the battery pack mounting portion 10 of the power tool main body 1. When the battery pack 100 is attached to the battery pack mounting portion 10 of the power tool main body 1 (step 400), the power from the battery pack 100 is supplied to the power tool main body 1, so that the power management circuit 62 of the battery pack 100 Is supplied and turned on (step 402), and the power management circuit 62 turns on the power circuit 61. As a result, the reference voltage VDD2 switches from 0V to 5V (step 403).

In FIG. 7, steps 404 to 410 on the middle left side are control flows of the microcomputer 60 a on the power tool body 1 side, and steps 411 to 416 on the middle right side are control flows of the microcomputer 250 a on the battery pack 100 side. Steps 404 to 410 and steps 411 to 416 are processed in parallel. When the reference voltage VDD2 is switched from 0 V to 5 V in step 403, the microcomputer 60a included in the control unit 60 on the power tool main body 1 starts (step 405). The microcomputer 60a controls the motor 5 on the power tool main body 1 side (step 406), but the details of the motor control are the same as those in the related art, and a detailed description thereof will be omitted.

When the microcomputer 60a on the main body side is started, the reference voltage VDD2 (approximately 5 V) is applied to the LD terminal 28 as described with reference to FIG. 3, so that the power supply management circuit 222 is turned on and the power supply circuit 221 is also turned on. , The reference voltage VDD1 switches from 0 V to 3.3 V (steps 402 and 403). As a result of this switching, the control unit 250 of the battery pack 100 is activated (Step 414). At this time, the microcomputer 250a sends a power self-holding signal 224 to the power management circuit 222 (step 415). As long as the self-holding signal 224 from the control unit 250 is in the ON state, the power management circuit 222 maintains the ON state in which the power circuit 221 continues to output. Next, the microcomputer 250a on the battery pack side performs battery protection control (step 416). Since the battery protection control is the same as a known control method, a detailed description is omitted here.

If the operator turns off the trigger switch 4 during the control of step 406 (step 407), the motor 5 stops. Then, the microcomputer 60a on the main body side continues to send the self-holding signal 62a to the power management circuit 62 for a predetermined time after the trigger switch 4 is turned off, so that the power management circuit 62 turns the power circuit 61 on. maintain. When the ON state is maintained for a predetermined time (step 408), the microcomputer of the control unit 60 turns off (turns low) the self-holding signal 62a sent to the power management circuit 62, and the power management circuit 62 The output of the reference voltage VDD2 from 61 is stopped. When the power supply circuit 61 is turned off, the reference voltage VDD2 changes from 5V to 0V (step 410). When the reference voltage VDD2 becomes 0 V, the control unit 60 including the microcomputer 60a loses power and shuts down (step 417).

When the microcomputer 60a on the main body side shuts down, the voltage of the LD terminal 28 drops from approximately 5V to approximately 0V (step 418). Then, the microcomputer 250a on the battery pack side detects that the voltage of the LD terminal 168 has been switched by the output change of the terminal voltage detection circuit 228. The microcomputer 250a keeps transmitting the self-holding signal 224 for a predetermined time, so that the power management circuit 222 maintains the power circuit 221 in the on state. When the ON state is maintained for a predetermined time (step 419), the microcomputer of the control unit 250 stops (turns low) the self-holding signal 224 sent to the power management circuit 222 (step 420). Then, the power supply circuit 221 is turned off, the reference voltage VDD1 changes from 3.3 V to 0 V (step 421), and the control unit 250 including the microcomputer 250a shuts down by losing power (step 422).

FIG. 8 is a diagram illustrating a control procedure of an operation example 2 of the battery pack 100 according to the present embodiment, and is a flowchart illustrating an operation example 2 of the power tool main body 1 in which the control unit 60 on the main body side also includes a microcomputer. . This flowchart is started when an operator attaches the battery pack 100 to the battery pack mounting portion 10 of the electric power tool main body 1. The procedure from steps 400 to 406 and 411 to 416 is the operation example shown in FIG. Therefore, the repeated description is omitted. Here, the control unit 60 controls the motor in step 406 on the power tool main body 1 side, and when the operator operates the trigger switch 4, the start and stop of the motor 5 are repeated a plurality of times. Here, it is assumed that the operator has removed the battery pack 100 from the power tool body 1 (step 430). Then, since the DC power from the battery pack 100 to the power supply circuit 61 on the power tool main body 1 side disappears, the power supply circuit 61 is turned off, and the reference voltage VDD2 becomes 0 V (step 431). The microcomputer 60a of the control unit 60 also shuts down due to the loss of power (step 432). On the other hand, on the battery pack 100 side, since the voltage of the LD terminal 168 becomes almost 0 V, the microcomputer 250a of the control unit 250 detects the state (step 418), and switches the microcomputer 250a to the normal mode until a predetermined time elapses. It stands by as it is (step 419). When the microcomputer 250a has been on for a predetermined time, the microcomputer 250a of the control unit 250 stops (turns low) the self-holding signal 224 sent to the power management circuit 222 (step 420). Then, the power supply circuit 221 is turned off, the reference voltage VDD1 is changed from 3.3 V to 0 V (step 421), and the microcomputer of the control unit 250 also shuts down by losing power (step 422). Stop.

As described above, if the connection between the battery pack 100 and the power tool main body 1 is released while the trigger switch 4 is turned on and the microcomputers 60a and 250a are activated, the terminal voltage of the LD terminal 168 becomes low. The microcomputer 250a can shift to the power saving mode (sleep mode, shutdown) when the terminal voltage of the LD terminal 168 is in the low state for a predetermined time or more.

FIG. 9 is a diagram illustrating a control procedure of Operation Example 3 of the battery pack 100 according to the present embodiment. FIG. 9 shows the control in the case where the power tool main body 1A having no control unit including a microcomputer is a counterpart device to which the battery pack 100 is connected (step 500). This flowchart is started when an operator attaches the battery pack 100 to the battery pack mounting portion 10 of the power tool main body 1 (step 501). The control procedure is shown on the left side of the operation of the power tool main body 1A.

When the battery pack 100 is mounted on the power tool main body 1A, the power tool main body 1A is in a usable state, and when the operator turns on the trigger switch 4 (step 502), power is supplied to the motor 5. Then, the motor 5 is turned on (step 503). When the worker turns off the trigger switch 4 after performing a predetermined operation (step 504), the power supplied to the motor 5 is cut off, so that the motor 5 stops and the motor 5 is turned off. (Step 505). The operation of steps 502 to 505 is repeated not only once but also plural times according to the work target.

In the control of the battery pack 100 corresponding to steps 502 to 505, when the battery pack 100 is mounted in step 501, almost the voltage VCC of the battery pack 100 is applied to the LD terminal 168 as shown in FIG. (Step 510). Then, a predetermined voltage is applied to the power management circuit 222 as the power activation signal 223, so that the power management circuit 222 is turned on (step 511). When the power management circuit 222 is activated, the power supply circuit 221 is activated and turned on, whereby the power supply voltage VDD1 is supplied from the power supply circuit 221 to the control unit 250 (step 512). As the power supply voltage VDD1, an MPU (Micro-processing unit) operating at an operating voltage of 3.3 V is used as a microcomputer included in the control unit 250 here. When the power supply voltage VDD1 is supplied to the control unit 250, the control unit 250 returns from the sleep mode and enters the on state, that is, the normal mode (step 513). Next, the microcomputer of the control unit 250 sends the self-holding signal 224 to the power management circuit 222 so that the power circuit 221 is kept on unless there is a power shutdown instruction from the microcomputer (step 514). . The power management circuit 222 turns on the power supply circuit when at least one of the power supply activation signal 223 and the self-holding signal 224 is high, and turns on the power supply circuit. When both of the signals 224 are at the low level, the operation of the power supply circuit 221 is stopped and the power supply circuit 221 is turned off. In step 515, the microcomputer of the control unit 250 on the battery pack side performs battery protection control. Since the battery protection control is the same as a known control method, a detailed description is omitted here.

After the procedure of steps 502 to 505 and 510 to 515 is performed once or repeatedly, the work by the worker is completed and the worker leaves the battery pack 100 mounted on the power tool main body 1A. When the microcomputer on the battery pack 100 side detects that the power tool main body 1A has been in the non-use state for a predetermined time or more, for example, a predetermined threshold value “threshold value T ₁ ” or more (step 516), the microcomputer changes its operation mode to “1”. The mode is shifted from the "normal mode" to the "sleep mode" (step 517). In this embodiment, to set the thresholds T ₁ as 2 hours, the last trigger operation of the power tool main body 1A shifts to the sleep mode after the lapse 2 hours from the completion. Note that the time required for shifting from the normal mode to the sleep mode when the battery pack 100 is not used is not limited to two hours, but may be set to several minutes to several hours. The sleep mode of the microcomputer is a mode in which the operation of the CPU and peripheral modules is stopped while the oscillation is stopped by intermittently oscillating the main clock. However, since the built-in regulator of the microcomputer keeps operating, the power is maintained being supplied, so that the built-in regulator can be used as an intermittent start trigger of main clock oscillation. Since the purpose of step 517 is to shift to the "power saving mode" in which the power consumption of the microcomputer is suppressed, the power saving mode is not limited to the sleep mode in which the main clock is intermittently oscillated. Instead, it may be realized by using other power saving technology for the microcomputer.

When the operator turns on the trigger switch 4 after the microcomputer shifts to the sleep mode in step 517 (step 506), the motor 5 is turned on by supplying power to the motor 5 (step 507). . Since the microcomputer on the battery pack 100 side monitors the current using the current detection circuit 227 when the microcomputer is intermittently started, the current value is equal to or more than a predetermined value, for example, to the externally connected device such as the power tool body 1. When the system detects exceeds the minimum current value serving as the threshold value I _min which can be determined that current flows (step 518), the microcomputer of the control unit 250 returns from the sleep mode to the normal mode (step 519). The microcomputer of the control unit 250, the voltage of the battery cell 146a~146e detects whether a predetermined threshold _{V 1} or less (step 520). Wherein the predetermined threshold value V ₁ was a predetermined value for determining that the battery cell 146a~146e is overdischarged state, since in the case of the threshold value V ₁ or the battery voltage is normal (usable state), The shutdown maintaining circuit 260 is in an operable state. While the microcomputer is operating in the normal mode, one or more of the voltage V of the battery cell 146a~146e is, when it becomes a threshold value V ₁ or less, the microcomputer judges that the overdischarge state ( Step 521), the switching element M1 is turned on (discharge inhibition state) by switching the discharge prohibition / permission signal from low to high, and the potentials of the LD terminals 28 and 168 are dropped to the ground potential (step 522). As a result, the gate voltage to the switching element M31 on the power tool main body 1A side decreases, so that the switching element M31 is turned off (interruption between the source and the drain) (step 508). As a result, the power supply to the motor 5 is cut off, and the rotation of the motor 5 stops (step 509).

On the battery pack 100 side, the voltage of the LD terminal 168 becomes almost 0 V as a result of Step 522 (Step 523). In this state, the control unit 250 waits until a predetermined time has elapsed (step 524), and turns off (low) the self-holding signal 224 for keeping the power management circuit 222 in the on state, thereby operating the power circuit 221. Is turned off (steps 525 and 526). Then, the supply of the reference voltage VDD1 (3.3 V) to the microcomputer of the control unit 250 is stopped, and the microcomputer is shut down (step 527). In this case, to maintain the operating state shutdown maintenance circuit 260, the value of the voltage VCC of the battery pack 100, far below the total voltage corresponding to the threshold V ₁ of the battery cell unit, becomes impossible even operation of the shutdown maintaining circuit 260 Until the voltage drops to the low voltage V ₀ (V ₀ <V ₁ ), the switching element M2 is maintained in the ON state. When the voltage is lower than the low voltage V _{0 at} which even the operation of the shutdown maintaining circuit 260 becomes impossible, even if a voltage of 3.3 V or more is applied to the LD terminal 168, the power management circuit 222 does not operate. There is no restart.

As described above, the battery pack 100 according to the present embodiment changes from the normal mode of the microcomputer to the power saving mode (for example, depending on whether the attached device, that is, the power tool body or the charging device includes the microcomputer. Sleep mode). In this power saving mode, when the trigger is pulled and the power tool main body 1 is started, the microcomputer is immediately restarted even in the normal mode, so that the power saving of the battery pack can be performed without hindering the operation of the power tool. Can be promoted. Further, when the sleep mode state continues for a long time, for example, when the sleep mode state lasts for one month or more, the microcomputer is shut down. Thereby, power consumption by the microcomputer of the battery pack 100 can be suppressed. This suppression of power consumption is particularly effective during standby when the battery pack 100 is not used.

As described above, the present invention has been described based on a plurality of embodiments. However, the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the gist of the present invention. For example, in the above-described embodiment, an example of an electric tool having a trigger switch and a motor as an electric device body has been described. However, the present invention is not limited to the electric tool, and other electric tools that operate using electric power from a battery pack are used. Also, it can be widely used for lighting equipment, audio equipment, electric equipment, and the like.

1, 1A power tool main body, 2 housing, 3 handle part, 4 trigger switch (operation switch), 5 motor, 8 tip tool holding section, 10 battery pack mounting section, 22 positive electrode input terminal, 25 control section, 27 negative input terminal, 28 LD terminal, 34 trigger switch, 60 control section, 60a microcomputer, 61 power supply circuit, 62 power supply management circuit, 62a self-holding signal, 63 switch State detection circuit, 64 current detection circuit, 65 battery voltage detection circuit, 66 gate signal, 67 signal line, 100 battery pack, 101 lower case, 110 upper case, 111 lower surface, 113 opening Reference numeral 114, a stepped portion, 115, an upper surface, 121 to 128, a slot, 131, a stopper, 132, a raised portion, 138a to 138b, a rail, 141, a latch, 142 ... Locking part, 146 cell unit, 146 a to 146 e battery cell, 162 positive electrode terminal, 167 negative electrode terminal, 168 LD terminal, 211 power supply circuit, 220 battery cell protection circuit, 221 power supply circuit, 222 ... power management circuit, 223 ... power activation signal, 224 ... self-holding signal, 227 ... current detection circuit, 228 ... terminal voltage detection circuit, 231 ... cell temperature detection means, 240 ... discharge inhibition control circuit, 241 ... discharge inhibition signal, 250 control unit, 250a microcomputer, 260 shutdown maintenance circuit, C1 capacitor, D1 diode, M1 to M3 (semiconductor) switching circuit, R1 to R5 resistor, ZD1 Zener diode, VDD1 power supply voltage (reference Voltage), VDD2: Reference voltage, VCC: Battery voltage

Claims (15)

A positive electrode terminal, a negative electrode terminal, an LD terminal for sending a stop signal to a mounted electric device main body, a plurality of battery cells, a protection circuit for monitoring the voltage of the battery cells, and a connection to the protection circuit; A microcomputer for monitoring a load state of the battery cell, and a battery pack having a power supply circuit for driving the microcomputer,
A battery pack characterized in that, when the electric device body includes a device-side microcomputer, the microcomputer shifts to the power-saving mode when the microcomputer determines that the device-side microcomputer has shifted to the power-saving mode. The battery pack according to claim 1, wherein the power saving mode is one of a sleep mode and a shutdown. A power management circuit for activating the power circuit according to the presence or absence of the voltage of the LD terminal;
The power management circuit operates the power circuit when there is a voltage at the LD terminal,
3. The battery pack according to claim 1, wherein the microcomputer stops the power supply circuit in response to a voltage disappearance of the LD terminal or after a lapse of a certain time after the power supply disappears. 4. The LD terminal of the battery pack is connected to ground via a switching element,
The microcomputer transmits an operation stop signal to the electric device main body by controlling a gate signal of the switching element to make the switching element conductive and ground the LD terminal to ground. Item 4. The battery pack according to item 3. The microcomputer is capable of outputting a self-holding signal for maintaining the ON state of the power supply circuit to the power management circuit,
5. The battery pack according to claim 3, wherein the power supply circuit stops operating due to the disappearance of the voltage of the LD terminal and the disappearance of the self-holding signal. 6. The microcomputer has a normal mode and a sleep mode.If the power supply circuit is activated and a state in which a discharge current _{equal to} or greater than the threshold value I _min has not been flowing for a certain period of time, the microcomputer shifts from the normal mode to the sleep mode, 6. The battery pack according to claim 5, wherein the operation returns to the normal mode from the sleep mode when a discharge current _{equal to} or more than the threshold value I _min is detected during the operation in the sleep mode. The microcomputer maintains an activated state at least while the device-side microcomputer is activated,
7. The battery pack according to claim 6, wherein when the device-side microcomputer shifts to a power saving mode, the mode shifts to a power saving mode. 8. The device according to claim 7, wherein the microcomputer determines whether the device-side microcomputer is included in the electric device main body by comparing a voltage of the positive terminal of the battery pack with a voltage of the LD terminal. The battery pack as described. When the microcomputer determines that the device-side microcomputer is not included in the electric device main body, the microcomputer detects that the electric device main body has been unused for a certain period of time or more while operating in the normal mode. 9. The battery pack according to claim 8, further comprising: shifting to the sleep mode, and, when detecting use of the electric device main body while operating in the sleep mode, shifting from the sleep mode to the normal mode. . The battery pack according to claim 9, wherein the microcomputer shuts itself down after a lapse of a predetermined time when detecting a disappearance of the voltage of the LD terminal while operating in the normal mode or the sleep mode. An electric device comprising a battery pack mounting portion for mounting the battery pack according to any one of claims 1 to 10, wherein the device is operated by electric power of the battery pack. The voltage of the electric device side LD terminal when attached to the main body of the electric device is the power supply voltage level of the microcomputer when the main body side has the device side microcomputer, and when the device side microcomputer is not included. The electric device according to claim 11, wherein? Is a voltage level of the positive terminal of the battery pack. A positive electrode terminal, a negative electrode terminal, an LD terminal for sending a stop signal to a mounted electric device main body, a plurality of battery cells, a protection circuit for monitoring the voltage of the battery cells, and a connection to the protection circuit; A microcomputer for monitoring a load state of the battery cell, and a battery pack having a power supply circuit for driving the microcomputer,
A terminal voltage detection circuit that detects a voltage of the LD terminal and outputs the voltage to the microcomputer;
The battery according to claim 1, wherein the microcomputer determines whether a device-side microcomputer of the electric device body has shut down based on a change in a voltage of the LD terminal, and shuts itself down when the device-side microcomputer shuts down. pack. The microcomputer shuts itself down after a predetermined time elapses, or shuts down or sleeps the microcomputer when the voltage of the LD terminal becomes zero, in conjunction with detecting that the device-side microcomputer has shut down. The battery pack according to claim 13, wherein: A power management circuit for activating the power supply circuit in response to a voltage change of the LD terminal, wherein the power management circuit activates the power supply circuit when a voltage is applied to the LD terminal to activate the microcomputer during shutdown; The battery pack according to claim 14, wherein:

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