JPWO2016136499A1 - Electric tool - Google Patents

Abstract

In order to provide an electric tool that cuts off the power supply from the battery pack to the motor, the first includes a motor (4) and a first battery cell, and outputs an abnormal signal when the first battery cell is in an abnormal state. And a control unit (5) for cutting off power supply to the motor by an abnormal signal output from the first battery pack attached to the terminal unit. The control means (5) can cut off the power supply to the motor (4) regardless of the presence or absence of an abnormal signal.

Description

The present invention relates to an electric tool that operates by feeding power from a battery pack.

In the cordless electric tool, the motor is rotated by the power supplied from the attached battery pack to drive the tool. And from a viewpoint of protection of the battery cell which comprises a battery pack, when an overdischarge and an overcurrent generate | occur | produce, the structure by which the battery pack itself interrupts | blocks the electric power feeding to the exterior is taken.

JP 2010-131749 A

However, in recent years, while battery cells have been increased in size and battery capacity has been increased, battery cells including small battery cells may be used as a power source depending on the application. In general, a small battery cell has a smaller electrode area than a normal battery cell and tends to be inferior in charge / discharge characteristics at a large current.

In addition, when some trouble occurs in the protection IC of the battery pack, overdischarge of the battery pack cannot be stopped, which may affect the battery life.

Therefore, an object of the present invention is to provide an electric tool that can reliably perform discharge control suitable for the performance of these battery packs while allowing power supply from battery packs of various specifications.

Another object of the present invention is to provide a power tool and a battery pack with a reduced number of terminals.

The power tool of the present invention includes a motor, a first battery cell, and a terminal part to which a first battery pack that outputs an abnormal signal when the first battery cell is in an abnormal state can be mounted; Control means for cutting off the power supply to the motor by the abnormal signal output from the first battery pack attached to the terminal portion, the control means regardless of the presence or absence of the abnormal signal The power supply to the motor can be cut off.

According to the above configuration, even when there is no abnormal signal from the battery pack, the power supply to the motor can be cut off on the electric tool side. Therefore, it is possible to prevent the battery cells in the battery pack attached to the terminal portion from deteriorating and extend the life of the battery pack to be attached.

Preferably, the terminal unit has a temperature terminal to which a signal of a battery temperature of the first battery pack is input, and the control unit has a case where the battery temperature input from the temperature terminal is higher than a predetermined value. The power supply to the motor is cut off.

Preferably, the control means cuts off power supply to the motor when a discharge current flowing from the first battery pack to the motor is higher than a predetermined value.

Preferably, the terminal portion includes a second battery pack that includes a second battery cell smaller than the first battery cell and outputs an abnormal signal when the second battery cell is in an abnormal state. The control means is selectively attachable to the first battery pack, and the control means is configured such that when the battery pack attached to the terminal portion is a second battery pack, the battery pack attached to the terminal portion is the first one. When the battery temperature reaches a battery temperature lower than the battery temperature at which the power supply to the motor is cut off in the case of one battery pack, the power supply to the motor is cut off.

Preferably, the terminal portion includes a second battery pack that includes a second battery cell smaller than the first battery cell and outputs an abnormal signal when the second battery cell is in an abnormal state. When the battery pack attached to the terminal portion is a second battery pack, the control means supplies power to the motor when the battery pack attached to the terminal portion is the first battery pack. When a discharge current lower than the discharge current for interrupting is reached, power supply to the motor is interrupted.

In general, the second battery cell having a small volume is more likely to deteriorate than the first battery cell having a large volume. In addition, the second battery cell having a small battery capacity is more likely to be deteriorated than the first battery cell having a large battery capacity. Therefore, when the second battery pack including the second battery cell is mounted, the temperature of the second battery cell is lower than the first temperature at which power supply from the first cell is cut off. When the second temperature is exceeded, the electric power tool itself forcibly stops the discharge of the second battery pack by cutting off the power supply from the terminal portion to the motor. As described above, the electric power tool stops the discharge from the second battery pack at the second temperature lower than the first temperature for the first battery cell, thereby suppressing the deterioration of the second battery cell. As a result, the life of the second battery pack is extended.

In general, the second battery cell having a small volume is more likely to deteriorate than the first battery cell having a large volume. In addition, the second battery cell having a small battery capacity is more likely to be deteriorated than the first battery cell having a large battery capacity. Therefore, when the second battery pack including the second battery cell is mounted, the discharge current value of the second battery cell is the first current value at which the power supply from the first cell is cut off. When the second current value is smaller than that, the electric power tool itself forcibly stops the discharge of the second battery pack by cutting off the power supply from the terminal portion to the motor. As described above, the electric power tool stops the discharge from the second battery pack at the second current value smaller than the first current value for the first battery cell, thereby deteriorating the second battery cell. Is suppressed, and the life of the second battery pack is extended.

The power tool of the present invention includes a motor, a first battery cell, and a terminal part to which a first battery pack that outputs an abnormal signal when the first battery cell is in an abnormal state can be mounted; Control means for interrupting power supply to the motor by the abnormal signal output from the first battery pack attached to the terminal portion, and the terminal portion includes a battery of the first battery pack. A temperature terminal to which a temperature signal is input is provided, and the control means can cut off the power supply to the motor according to the battery temperature input from the temperature terminal even when there is no abnormal signal. It is characterized by that.

According to the said structure, even if there is no abnormal signal from a battery pack, the electric power supply to a motor can be interrupted | blocked by the electric tool side according to battery temperature. Therefore, it is possible to prevent the battery cells in the battery pack attached to the terminal portion from deteriorating and extend the life of the battery pack to be attached.

Preferably, the control means cuts off the power supply to the motor when the battery temperature is higher than a predetermined value.

The power tool of the present invention includes a motor, a first battery cell, and a terminal part to which a first battery pack that outputs an abnormal signal when the first battery cell is in an abnormal state can be mounted; Control means for interrupting power supply to the motor by the abnormal signal output from the first battery pack attached to the terminal portion, and the terminal portion includes a battery of the first battery pack. A temperature terminal for inputting a temperature signal; and the control unit can cut off the power supply to the motor by any of the abnormal signal, the battery temperature, and the discharge current from the first battery pack. It is characterized by that.

According to the said structure, the electric power feeding to a motor can be interrupted | blocked by the electric tool side according to any of the abnormal signal from a battery pack, battery temperature, and discharge current. Therefore, it is possible to prevent the battery cells in the battery pack attached to the terminal portion from deteriorating and extend the life of the battery pack to be attached.

Preferably, the control means cuts off the power supply to the motor when the battery temperature is higher than a predetermined value or when the discharge current is higher than a predetermined value.

According to the said structure, deterioration of the battery cell in a battery pack can be prevented, and the lifetime of the battery pack with which it is mounted | worn can be achieved.

Preferably, the first battery pack includes battery cells, a battery-side terminal unit that is connected to the terminal unit and outputs a plurality of pieces of information of the battery cell, and information on the battery cell that is output to the terminal unit. A switching circuit for switching, and the control unit controls the motor based on the information.

According to the said structure, the number of the terminals provided in a terminal part can be reduced.

Preferably, the terminal unit includes a plurality of terminals, and the switching circuit switches the information output from one of the plurality of terminals.

According to the said structure, the number of the terminals provided in a terminal part can be reduced.

Preferably, the first battery pack includes a battery type identification unit having information on characteristics of the battery cell, and a battery state output unit that outputs a signal indicating the state of the battery cell, and the switching circuit includes The output signals of the battery type identification unit and the battery state output unit can be selectively output to the terminal unit.

According to the said structure, the number of the terminals provided in a terminal part can be reduced.

The charging device of the present invention has an excellent effect of suppressing the deterioration of the battery cell and extending the life of the battery pack including the battery cell. In addition, it is possible to provide a power tool and a battery pack with a reduced number of terminals.

1 is a circuit diagram of a power tool according to a first embodiment of the present invention. It is a circuit diagram of the battery pack with which an electric tool is mounted | worn. It is a flowchart which shows operation | movement of an electric tool. It is a circuit diagram with a battery pack and the charging device which charges a battery pack. It is a flowchart which shows operation | movement of a charging device.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a power tool 1 according to an embodiment of the present invention. The electric tool 1 is a cordless electric tool that operates by power supply from the battery pack 20, such as a circular saw, a plane, or an impact driver. The electric tool 1 includes a terminal portion 2, an inverter circuit 3, a motor 4, a microcomputer 5, a gate driver 6, and a trigger switch 7 in the main body. At least two types of battery packs 20 can be selectively attached to the terminal portion 2.

The terminal unit 2 is provided in the main body, and includes a plus terminal 11 and a minus terminal 12 for supplying power, a V terminal 13, an LD terminal 14, and a T terminal 15.

The plus terminal 11 and the minus terminal 12 are respectively connected to the input side of the inverter circuit 3. Further, the plus terminal 11 can be connected to the discharge plus terminal of the battery pack 20, and the minus terminal 12 can be connected to the discharge minus terminal of the battery pack 20.

The V terminal 13 is connected to the microcomputer 5 and transmits an activation signal output from the microcomputer 5 to the battery pack 20.

The LD terminal 14 is connected to the microcomputer 5 and transmits an abnormal signal such as an overdischarge signal output from the battery pack 20 to be mounted to the microcomputer 5. The abnormal signal is generated when the microcomputer 24 of the battery pack 20 overcharges, overdischarges or overcharges the battery cell 21a when at least one of the battery cells 21a of the battery pack 20 is overcharged, overdischarged, or overcurrent occurs. This is a signal for notifying an external device of a current.

The T terminal 15 is connected to the microcomputer 5 as a temperature terminal, and transmits a battery state signal output from the battery pack 20 to the microcomputer 5.

The inverter circuit 3 has six switching elements Q1 to Q6, and the motor 4 is connected to the output side. The inverter circuit 3 adjusts the amount of power supplied from the battery pack 20 to the motor 4 by performing a switching operation such as duty ratio control with the switching elements Q1 to Q6.

The motor 4 is a brushless motor, is rotated by electric power supplied via the inverter circuit 3, and serves as a drive source for work tools such as a saw blade and a tip tool attached to the main body.

The microcomputer 5 obtains information on the battery pack 20 as a control means, while outputting an activation signal to the battery pack 20 to be mounted. Then, the microcomputer 5 generates a control signal for the switching operation based on the information and outputs the control signal to each of the switching elements Q1 to Q6 via the gate driver 6, thereby supplying power from the battery pack 20 to the motor 4. Is possible. Further, when the microcomputer 5 acquires an abnormal signal from the battery pack 20 via the LD terminal 14 or when the temperature information or the discharge current amount of the battery pack 20 acquired via the T terminal 15 reaches a predetermined level. Then, the power supply to the motor 4 is stopped.

Further, a trigger switch 7 is connected to the microcomputer 5. The microcomputer 5 changes the duty ratio of the switching elements Q <b> 1 to Q <b> 6 according to the operation amount such as the pulling amount of the trigger switch 7 and adjusts the amount of power supplied to the motor 4. Further, when the microcomputer 5 detects at least one of overdischarge and abnormality of the battery pack 20, all of the switching elements Q1 to Q6 are opened to stop the rotation of the motor 4.

The battery pack 20 attached to the electric tool 1 shown in FIG. 1 will be described with reference to FIG. In the present embodiment, at least two types of battery packs having different battery cell characteristics can be selectively attached to the electric power tool 1, except for the battery cell characteristics. Since both are the same, the configuration of the battery pack will be described below.

The battery pack 20 includes a battery set 21 including at least one or more secondary batteries, a terminal unit 22, a power supply circuit unit 23, a microcomputer 24, a current detection circuit 25, a first temperature detection unit 26, A second temperature detection unit 27, a first switching circuit 28, a battery type determination resistor 29, and a second switching circuit 30 are included.

The battery set 21 is composed of one of the battery cells 21a made of a secondary battery or a plurality of battery cells 21a connected in series. In the present embodiment, the battery set 21 has five lithium ion battery cells 21a having a rated voltage of 3.6 V connected in series. In addition, the kind of battery cell 21a is not limited to a lithium ion battery, A suitable secondary battery can be used. Further, the number of battery cells 21a and the connection form thereof are merely examples, and the battery pack 20 may include battery cells connected in parallel.

The terminal portion 22 is provided in the main body of the battery pack 20 to connect the battery pack 20 to an external device, and includes a discharge plus terminal 32, a charge plus terminal 33, a charge / discharge minus terminal 34, a V terminal 35, and an LS. A terminal 36, an LD terminal 37, and a T terminal 38 are provided.

The discharge plus terminal 32 is connected to the positive electrode of the battery cell 21 a located on the high potential side of the battery set 21, that is, the positive electrode 21 </ b> A of the battery set 21. The charge plus terminal 33 is connected to the positive electrode 21 </ b> A of the battery set 21 through the fuse 39. The fuse 39 is connected to the microcomputer 24 and is cut when the microcomputer 24 outputs an overcharge signal from the first overcharge signal output unit 24A. On the other hand, the charge / discharge minus terminal 34 is connected to the negative electrode of the battery cell 21 a located on the low potential side of the battery set 21, that is, the negative electrode 21 </ b> B of the battery set 21.

The V terminal 35 is connected to the power supply circuit unit 23 and transmits a start signal output from the external device to the power supply circuit unit 23 to start the power supply circuit 23B included therein.

The LS terminal 36 is connected to the second overcharge signal output unit 24B of the microcomputer 24 via the first switching circuit 28, and receives the overcharge signal output from the microcomputer 24 or the output signal of the first temperature detection unit 26. Selectively transmit to external device.

The LD terminal 37 is connected to the abnormal signal output unit 24C of the microcomputer 24, and transmits an abnormal signal output from the microcomputer 24 to an external device. In one embodiment, the abnormal signal is generated when the voltage per cell during discharge is reduced to 2.5 V in the case of a small battery, or when the voltage per cell is reduced to 2.0 V in the case of a normal battery. Is output.

The T terminal 38 selectively transmits a battery state signal output from the battery type determination resistor 29 or the battery state signal output unit 24D of the microcomputer 24 to an external device. The battery state signal output unit 24D corresponds to battery state output means.

Therefore, when the battery pack 20 is connected to the electric power tool 1, the discharge positive terminal 32, the charge / discharge negative terminal 34, the V terminal 35, the LD terminal 37, and the T terminal 38 are respectively positive of the electric power tool 1. The terminal 11, the minus terminal 12, the V terminal 13, the LD terminal 14, and the T terminal 15 are connected. On the other hand, when the battery pack 20 is connected to the charging device, the charging plus terminal 33, the charging / discharging minus terminal 34, the V terminal 35, the LS terminal 36, and the T terminal 38 are respectively the plus terminal of the charging device. The negative terminal, the V terminal, the LS terminal, and the T terminal are connected. Details will be described later.

The power supply circuit unit 23 includes a power management unit 23A and a power supply circuit 23B, and when the activation signal is input to the power management unit 23A, the power supply circuit 23B is activated. When the power supply circuit 23B is activated, power is supplied from the battery set 21 to the microcomputer 24, and the microcomputer 24 is activated.

The microcomputer 24 monitors the cell voltage and the cell current of each battery cell 20a, detects the occurrence of overdischarge or overcurrent, and outputs an abnormal signal from the abnormal signal output unit 24C when detecting it. Further, the microcomputer 24 continuously or intermittently outputs a battery state signal having values corresponding to the temperature of the battery set 21 and the battery current.

The current detection circuit 25 is provided between the negative electrode 21 </ b> B and the negative terminal 34 of the battery set 21 and detects a current output from the battery set 21. Specifically, the current detection circuit 25 includes a shunt resistor, and calculates a current value from a voltage drop value caused by the shunt resistor.

The first temperature detection unit 26 includes a thermistor and detects the temperature of the battery set 21 when the battery pack 20 is connected to the charging device.

The second temperature detection unit 27 includes a thermistor and is connected to the information storage unit 24E of the microcomputer 24. The second temperature detection unit 27 detects the temperature of the battery set 21 when the battery pack 20 is connected to the electric tool 1 and the microcomputer 24. Output to.

The first switching circuit 28 is provided between the overcharge signal output unit 24B of the microcomputer 24 and the LS terminal 36, and selects the overcharge signal output from the microcomputer 24 and the output signal of the first temperature detection unit 26. To the LS terminal 36.

The second switching circuit 30 is provided as a switching means between the battery status signal output unit 24D of the microcomputer 24 and the T terminal 38, and selectively selects the battery status signal output from the microcomputer 24 and the battery type discrimination resistor 29. Connect to T terminal 38. For example, in one embodiment, the second switching circuit 30 connects the battery type determination resistor 29 via the switching circuit 30 to the T terminal 38 only during the first time after the microcomputer 24 is activated by the activation signal. After the first time has elapsed, the battery state signal output unit 24D is connected to the T terminal 38. In another embodiment, the second switching circuit 30 may be configured such that the battery state signal output unit 24D and the battery type determination resistor 29 are alternately and periodically connected to the T terminal 38.

The battery type identification resistor 29 has a specific resistance value corresponding to the type and number of battery cells 21a constituting the battery set 21 and a connection method such as series or parallel as battery type identification means. When the battery pack 20 is connected to the electric tool 1 or the charging device, the electric tool 1 or the charging device reads the resistance value of the battery type determination resistor 29 via the T terminal 38 and the second switching circuit 30, and sets the battery set. The type, number and connection method of the battery cells 21 a constituting the battery 21 are determined. The information that the battery type determination resistor 29 has is information that is unique to the battery pack 20 that is subject to charge / discharge control and the battery cells 21 a that constitute the battery pack 20. Specifically, the information included in the battery type determination resistor 29 includes the type of the battery cell 21a, the volume per cell, the battery capacity, the rated voltage, and the allowable maximum charging current. Includes a total number of battery cells 21a, a connection configuration such as series connection or parallel connection, a rated voltage, a rated capacity, an allowable maximum charging current, and an allowable temperature.

In the present invention, the characteristic of the battery cell 21a is at least one of the type of the battery cell 21a, the volume per cell, the battery capacity, the rated voltage, or the allowable maximum charging current.

Furthermore, in the present embodiment, at least two types of battery packs having different battery cell characteristics can be selectively attached to the electric power tool 1. In the present invention, the characteristics of the battery cells are different from each other when the information type of the battery type discrimination resistor 29 is different, and when the values of the information are different even if the information is the same type. Means.

For example, the power tool 1 can be mounted with the first battery pack 20A and the second battery pack 20B having different volumes per cell of the battery pack 20. The volume per battery cell constituting the second battery pack 20B is smaller than the volume per battery cell constituting the first battery pack 20A. In the present embodiment, for example, the battery cell of the first battery pack is a normal battery, and is formed of a cylindrical cell having an outer diameter of φ18 mm and a length of 65 mm. On the other hand, the battery cell of the second battery pack is a small battery, and is composed of a cylindrical cell having an outer diameter of 14 mm and a length of 50 mm. In this case, the first battery pack 20A is a normal battery, and the second battery pack 20B is a small battery.

Further, the power tool 1 can be mounted with a third battery pack 20C and a fourth battery pack 20D having different battery capacities per cell of the battery pack 20. The battery capacity per cell of the battery cells constituting the fourth battery pack 20D is smaller than the battery capacity per cell of the battery cells constituting the third battery pack 20C. In the present embodiment, for example, the battery cell constituting the third battery pack is a normal battery, and its battery capacity is 3.0 Ah. On the other hand, the battery cell which comprises a 4th battery pack is a small battery, The battery capacity is 1.0Ah. In this case, the third battery pack 20C is a normal type battery pack, and the fourth battery pack 20D is a small battery pack.

Next, with reference to FIG. 3, the motor stop process of the electric tool will be described. In the flowchart shown in FIG. 3, unless otherwise specified, the microcomputer 5 of the electric tool 1 performs each process.

In S101, it is determined whether or not the battery pack 20 is attached to the electric power tool 1. When the battery pack 20 is attached to the electric power tool 1, the plus terminal 11 and the minus terminal 12 of the electric tool 1 are electrically connected to the discharge plus terminal 32 and the charge / discharge minus terminal 34 of the battery pack 20, respectively. Further, the V terminal 13, the LD terminal 14 and the T terminal 15 of the electric power tool 1 are connected to the V terminal 35, the LD terminal 37 and the T terminal 38 of the battery pack 20, respectively, and between the electric power tool 1 and the battery pack 20. Signals can be sent and received.

When it is determined that the battery pack 20 is attached (S101: YES), the microcomputer 5 sends a start signal to the power supply circuit unit 23 of the battery pack 20 to start the microcomputer 24 of the battery pack 20. Since the microcomputer 24 of the battery pack 20 connects the battery type determination resistor 29 to the T terminal 38 via the second switching circuit 30 in response to the activation signal, the microcomputer 5 reads the battery type determination resistor 29, Types of battery cells 21a, volume per cell, battery capacity, rated voltage, allowable maximum charging current, total number of battery cells 21a constituting the battery pack 20, connection configuration such as series connection or parallel connection, rated voltage, Get the rated capacity, allowable maximum charging current and allowable temperature.

In S102, it is determined whether or not the trigger switch 7 has been pulled. When the trigger switch 7 is pulled (S102: YES), the microcomputer 5 determines in S103 whether the attached battery pack is a normal battery or a small battery. That is, if it is determined from the information read from the battery type discrimination resistor 29 that the first battery packs 20A and 20C, which are normal batteries, are mounted (S103: NO), the process proceeds to S109. In S109, whether or not the discharge current from the first battery packs 20A, 20C is the predetermined value Ib, in the next S110, whether there is an abnormal signal from the battery packs 20A, 20C, and in S111, the battery packs 20A, 20C. It is determined whether or not the battery temperature is equal to or higher than Tb. Note that whether or not the discharge current from the first battery packs 20A and 20C is the predetermined value Ib in S109, and further whether or not the battery temperature of the battery packs 20A and 20C is equal to or higher than Tb in S111. The first condition. The predetermined value Ib corresponds to the first current value.

When any of S109 to S111 is applicable, the microcomputer 5 determines that the discharge from the battery packs 20A and 20C should be stopped because an abnormal state has occurred in the battery packs 20A and 20C, and the switching operation of the inverter circuit 3 is performed. Stop. That is, the discharge from the battery packs 20A and 20C is forcibly cut off (S107).

In particular, in S111, no abnormality signal is output from the battery packs 20A and 20C, that is, the microcomputer 24 of the battery packs 20A and 20C determines that there is no abnormality in the battery packs 20A and 20C themselves. However, the microcomputer 5 on the power tool 1 side determines that the discharge should be stopped based on the temperature information sent from the battery packs 20A and 20C, stops the switching operation of the inverter circuit 3, and stops the battery packs 20A and 20A. The discharge from 20C is forcibly stopped (S107).

On the other hand, when the microcomputer 5 determines in S103 that the small battery, that is, the battery packs 20B and 20D is mounted (S103: YES), the microcomputer 5 proceeds to S104. Whether or not the discharge current from the second battery packs 20B and 20D is a predetermined value Ia smaller than Ib in S104 (Ia <Ib), whether or not there is an abnormal signal from battery packs 20B and 20D in S105, Whether or not the battery temperature of the battery packs 20B and 20D is equal to or higher than Ta lower than Tb is determined (Ta <Tb). Whether or not the discharge current from the second battery packs 20B and 20D is a predetermined value Ia smaller than Ib (Ia <Ib), in S106, the battery temperature of the battery packs 20B and 20D is Ta or higher than Tb. Whether or not there is a second condition. The predetermined value Ia corresponds to the second current value.

In the case of any of S104 to S106, the microcomputer 5 determines that the discharge from the battery packs 20B and 20D should be stopped, and stops the switching operation of the inverter circuit 3. That is, the discharge from the battery packs 20B and 20D is forcibly stopped (S107).

Similar to the normal battery, even in the case of a small battery, even if an abnormal signal is not output from the battery packs 20B and 20D in S105, that is, the microcomputer 24 of the battery packs 20B and 20D is not connected to the battery packs 20B and 20D itself. Even when it is determined that there is no abnormality, the microcomputer 5 on the power tool 1 side determines that the discharge should be stopped based on the temperature information sent from the battery pack 20 (S106: YES). ) The switching operation of the inverter circuit 3 is stopped, and the discharge from the battery pack 20 is forcibly stopped (S107).

After stopping the switching operation of the inverter circuit 3 in S107, it is confirmed whether or not the battery pack is connected in S108. If the battery pack is removed (S108: NO), the process returns to S101.

In S105 and S110, the microcomputer 24 of the battery pack 20 outputs overdischarge as an abnormal signal. However, an abnormal signal for notifying overcurrent from the battery pack 20 may be used.

In the present embodiment, not only the output of the abnormal signal from the battery pack 20 but also the microcomputer 5 of the electric tool 1 to which the battery pack 20 is attached acquires information on the temperature and current of the battery pack 20 and includes the information in the information. Based on this, it is determined whether or not power supply to the battery pack 20 is stopped. Therefore, it is possible to control the discharge of the battery pack by both the battery pack and the electric tool.

Furthermore, even if there is no output of an abnormal signal from the battery pack 20, the discharge of the battery pack 20 can be stopped by the judgment of the microcomputer 5 of the electric power tool 1, so that the battery pack 20 can be discharged without burden. .

Moreover, the conditions for stopping the discharge are changed according to the characteristics of the battery cells constituting the battery pack. In particular, the microcomputer 5 of the electric power tool 1 detects from the information from the battery type discrimination resistor 29 that the attached battery pack is a small battery, so that the voltage from the battery pack is higher than that of a normal battery. Since the discharge is stopped, deterioration of the small battery can be suppressed and the battery life can be improved.

Further, since the battery pack selectively connects the battery type discrimination resistor 29 and the battery state signal output unit 24D of the microcomputer 24 to the T terminal 38 by the second switching circuit 30, the battery pack 20 is connected to the terminal unit 22 of the battery pack 20. The configuration of the battery pack 20 can be simplified by preventing an increase in the number of terminals provided.

Next, charging of the battery pack 20 will be described below with reference to FIGS. 4 and 5.

As shown in FIG. 4, the charging device 40 that charges the battery pack 20 includes a terminal portion 41 to which the terminal portion 22 of the battery pack 20 is attached. The terminal portion 41 includes a plus terminal 42, a minus terminal 43, a V terminal 44, an LS terminal 45, and a T terminal 46. The plus terminal 42, the minus terminal 43, the V terminal 44, the LS terminal 45, and the T terminal 46 are the charge plus terminal 33, the charge / discharge minus terminal 34, the V terminal 35, and the LS of the battery pack 20, respectively. The terminal 36 and the T terminal 38 are connected.

The charging device 40 has a microcomputer inside, and starts charging the battery pack 20 via a power line (not shown) when the battery pack 20 is mounted.

Next, charging of the battery pack 20 will be described below with reference to FIG.

In S201, it is determined whether or not battery pack 20 is attached to charging device 40. When the battery pack 20 is attached to the charging device 40, the plus terminal 42 and the minus terminal 43 of the charging device 40 are electrically connected to the charging plus terminal 33 and the charging / discharging minus terminal 34 of the battery pack 20, respectively. Further, the V terminal 44, the LS terminal 45, and the T terminal 46 of the charging device 40 are respectively connected to the V terminal 35, the LS terminal 36, and the T terminal 38 of the battery pack 20, and between the charging device 40 and the battery pack 20. Signals can be sent and received.

When it is determined that the battery pack 20 is attached (S201: YES), the microcomputer of the charging device 40 sends an activation signal to the power supply circuit unit 23 of the battery pack 20 to activate the microcomputer 24 of the battery pack 20. The microcomputer 24 of the battery pack 20 connects the battery type determination resistor 29 to the T terminal 38 via the second switching circuit 30 in response to the activation signal. Reading, type of battery cell 21a, volume per cell, battery capacity, rated voltage, allowable maximum charging current, total number of battery cells 21a constituting battery pack 20, connection configuration such as serial connection or parallel connection, rating The voltage, the rated capacity, the allowable maximum charging current and the allowable temperature are acquired, and the charging condition of the battery pack 20 is set.

In S202, the charging device determines whether the attached battery pack 20 is a normal battery or a small battery. That is, when it is determined from the information read from the battery type determination resistor 29 that the first battery packs 20A and 20C, which are normal batteries, are mounted (S202: NO), the process proceeds to S210. In S210, it is determined whether or not an abnormal signal is generated from the battery packs 20A and 20C. When the abnormal signal is output from the battery packs 20A and 20C (S210: YES), the charging is stopped (S208). If the abnormality signal is not output from the battery pack 20A, 20C (S210: NO) , it begins charging at a charging current I ₂ battery pack 20A, the constant current charging control of 20C, 1 battery voltage per cell V ₂ Upon reaching (4.175V) (S212: YES) , the switching to the constant voltage charging control of the battery voltage V ₂ (S213), When the charging current becomes I ₄ (S214: YES), stops the charging (S208) .

On the other hand, when the microcomputer 5 determines in S202 that the small battery, that is, the battery packs 20B and 20D is attached (S202: YES), the microcomputer 5 proceeds to S203. In S203, it is determined whether or not an abnormal signal is generated from the battery packs 20B and 20D. When the abnormal signal is output from the battery packs 20B and 20D (S203: YES), the charging is stopped (S208). When the abnormal signal is not output from the battery packs 20B and 20D (S203: NO), charging is started by the constant current charging control of the battery packs 20B and 20D with the charging current I ₁ smaller than the charging current I _2. When the battery voltage is V ₂ reaches a smaller _{V 1 (4.15V) (S205:} YES), the switching to the constant voltage charging control of the battery voltage V ₁ (S206), the charging current becomes I ₄ smaller I ₃ If so (S207: YES), the charging is stopped (S208).

When the connection between the charging device 40 and the battery pack 20 is released (S209: NO), the process returns to S201.

As described above, since the charging conditions are individually set according to the characteristics of the battery pack such as a small battery and a normal battery, the life of the small battery having inferior charge / discharge performance at a large current as compared with the normal battery is improved. Can be improved.

DESCRIPTION OF SYMBOLS 1 ... Electric tool, 2 ... Terminal part, 4 ... Motor, 20 ... Battery pack, 21a ... Battery cell, 24 ... Microcomputer as control means

Claims (14)

A motor,
A terminal portion that includes a first battery cell and is attachable to a first battery pack that outputs an abnormal signal when the first battery cell is in an abnormal state;
Control means for cutting off the power supply to the motor by the abnormal signal output from the first battery pack attached to the terminal portion,
The electric power tool characterized in that the control means can cut off the power supply to the motor regardless of the presence or absence of the abnormal signal. The terminal portion has a temperature terminal to which a battery temperature signal of the first battery pack is input,
2. The electric tool according to claim 1, wherein the control unit cuts off power supply to the motor when the battery temperature input from the temperature terminal is higher than a predetermined value. 2. The electric tool according to claim 1, wherein the control unit cuts off power supply to the motor when a discharge current flowing from the first battery pack to the motor is higher than a predetermined value. The terminal portion includes a second battery cell that is smaller than the first battery cell, and outputs a second battery pack that outputs an abnormal signal when the second battery cell is in an abnormal state. 1 battery pack can be selectively installed,
When the battery pack attached to the terminal portion is a second battery pack, the control means shuts off power supply to the motor when the battery pack attached to the terminal portion is the first battery pack. The power tool according to claim 1, wherein power supply to the motor is cut off when a battery temperature lower than the temperature is reached. The terminal portion includes a second battery cell smaller than the first battery cell, and a second battery pack that outputs an abnormal signal when the second battery cell is in an abnormal state can be mounted. Yes,
In the case where the battery pack attached to the terminal portion is a second battery pack, the control means discharges power supply to the motor when the battery pack attached to the terminal portion is the first battery pack. The power tool according to claim 1, wherein power supply to the motor is interrupted when a discharge current lower than the current is reached. A motor,
A terminal portion that includes a first battery cell and is attachable to a first battery pack that outputs an abnormal signal when the first battery cell is in an abnormal state;
Control means for cutting off the power supply to the motor by the abnormal signal output from the first battery pack attached to the terminal portion,
The terminal portion has a temperature terminal to which a battery temperature signal of the first battery pack is input,
The electric power tool characterized in that the control means can cut off the power supply to the motor in accordance with the battery temperature inputted from the temperature terminal even when there is no abnormal signal. The power tool according to claim 6, wherein the control unit cuts off power supply to the motor when the battery temperature is higher than a predetermined value. A motor,
A terminal portion that includes a first battery cell and is attachable to a first battery pack that outputs an abnormal signal when the first battery cell is in an abnormal state;
Control means for cutting off the power supply to the motor by the abnormal signal output from the first battery pack attached to the terminal portion,
The terminal portion has a temperature terminal to which a battery temperature signal of the first battery pack is input,
The electric power tool characterized in that the control means can cut off the power supply to the motor by any one of the abnormal signal, the battery temperature, and the discharge current from the first battery pack. The electric power tool according to claim 8, wherein the control means cuts off the power supply to the motor when the battery temperature is higher than a predetermined value or when the discharge current is higher than a predetermined value. The terminal portion includes a second battery cell that is smaller than the first battery cell, and outputs a second battery pack that outputs an abnormal signal when the second battery cell is in an abnormal state. 1 battery pack can be selectively installed,
When the battery pack attached to the terminal portion is a second battery pack, the control means shuts off power supply to the motor when the battery pack attached to the terminal portion is the first battery pack. The power tool according to any one of claims 6 to 9, wherein power supply to the motor is cut off when a battery temperature lower than the temperature is reached. The terminal portion includes a second battery cell smaller than the first battery cell, and a second battery pack that outputs an abnormal signal when the second battery cell is in an abnormal state can be mounted. Yes,
In the case where the battery pack attached to the terminal portion is a second battery pack, the control means discharges power supply to the motor when the battery pack attached to the terminal portion is the first battery pack. The power tool according to any one of claims 6 to 9, wherein power supply to the motor is cut off when a discharge current lower than the current is reached. The first battery pack is
A battery cell;
A battery side terminal portion connected to the terminal portion and outputting a plurality of pieces of information of the battery cells;
A switching circuit for switching the information of the battery cell to be output to the terminal unit,
The electric power tool according to any one of claims 1 to 11, wherein the control unit controls the motor based on the information. The terminal portion has a plurality of terminals,
The power tool according to claim 12, wherein the switching circuit switches the information output from one of the plurality of terminals. The first battery pack is
Battery type identification means having information on the characteristics of the battery cells;
Battery state output means for outputting a signal indicating the state of the battery cell,
The electric power tool according to claim 12 or 13, wherein the switching circuit selectively outputs output signals of the battery type identification unit and the battery state output unit to the terminal unit.

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