CN114792849A

CN114792849A - Battery pack, electric tool system and charging combination

Info

Publication number: CN114792849A
Application number: CN202111533261.6A
Authority: CN
Inventors: 杨东; 胡桂伍; 胡中操
Original assignee: Nanjing Chervon Industry Co Ltd
Current assignee: Nanjing Chervon Industry Co Ltd
Priority date: 2021-01-26
Filing date: 2021-12-15
Publication date: 2022-07-26

Abstract

The invention discloses a battery pack, an electric tool system and a charging combination, comprising: a housing; a battery cell assembly; the battery cell assembly comprises a plurality of non-cylindrical battery cell units; the cell units are arranged in a stacked manner; the battery cell elastic piece is positioned on at least one side of the battery cell assembly to protect the battery cell assembly; the battery pack interface is at least electrically connected with the electric core component; the switch is connected between the electric core assembly and the battery pack interface; the deformation sensor is positioned on one side of the battery cell elastic part and is used for detecting parameters related to the deformation quantity of the battery cell assembly; a controller configured to: when the sensor detects that the parameters related to the deformation quantity of the core assembly meet the preset conditions, the sensor outputs a control signal for switching off the switch so as to switch off the electrical connection between the core assembly and the battery pack interface. By adopting the technical scheme, the potential safety hazard of explosion caused by internal deformation of the battery pack can be reduced, and the safety and the reliability of the battery pack are improved.

Description

Battery pack, electric tool system and charging combination

Technical Field

The invention relates to a battery pack, an electric tool system and a charging combination.

Background

Based on the requirement of portability, more and more electric tools adopt a battery pack as a power source.

The existing battery pack for supplying power to the electric tool mainly adopts cylindrical lithium cells, and the plurality of cylindrical lithium cells are connected in series and parallel to ensure sufficient electric energy output so as to improve the cruising ability and the operating efficiency of the electric tool.

The cylinder type lithium cell is because the evaporation of lithium ion electrolyte in the charging process, and the battery is inside can produce a small amount of gas, and under normal conditions, this part of gas can be absorbed when the battery discharges, however, frequent because of long-time charging leads to charge and discharge current too big, then can aggravate gaseous production, makes the internal pressure of battery increase, leads to the battery inflation phenomenon to appear. Furthermore, the battery may expand and deform during the collision with external force and the manufacturing process, which may affect the battery characteristics, and thus the battery life and stability. As battery technology has developed, pouch-shaped batteries have been produced, but they generally use a flexible outer case, so that the pouch-shaped batteries are more susceptible to swelling deformation during charge and discharge. At the same time, in the worst case, combustible gases such as electrolytes or broken materials may be discharged to the outside, which may lead to a fire or explosion.

Therefore, in the electric power tool powered by the battery pack, there is a safety risk of explosion due to expansion deformation of the battery pack.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a battery pack, an electric tool system and a charging system, which can reduce the potential safety hazard of explosion caused by internal deformation of the battery pack and improve the safety and reliability of the battery pack.

In order to achieve the above object, the present invention adopts the following technical solutions:

a battery pack, comprising: a housing comprising an upper housing and a lower housing assembled at an interface to form an internal cavity; an electrical core assembly disposed within the internal cavity; the battery cell assembly comprises a plurality of non-cylindrical battery cell units; the battery cell units are arranged in a stacked manner; a cell elastic member disposed around the cell assembly to seal the cell assembly; the battery pack interface is at least electrically connected with the electric core assembly; a switch connected between the battery pack assembly and the battery pack interface; the deformation sensor is positioned on one side of the electric core elastic piece and used for detecting parameters related to the deformation quantity of the electric core assembly; a controller configured to: when the sensor detects that the parameter that the electricity core subassembly is correlated with the deformation volume satisfies the preset condition, output makes the control signal of switch disconnection is in order to cut off electricity core subassembly with electric connection between the battery package interface.

Optionally, the sensor is located on the upper side of the cell elastic member and has a preset distance from the upper surface of the cell elastic member.

Optionally, the preset distance ranges from greater than or equal to 1 mm to less than or equal to 6 mm.

Optionally, comprising: the first supporting plate is positioned on the upper side of the lower shell, and an accommodating space for accommodating the electric core assembly is formed between the first supporting plate and the lower shell; the sensor is arranged on the lower surface of the first supporting plate.

Optionally, comprising: the second supporting plate comprises an elastic plate with a certain elastic coefficient, and is arranged between the electric core assembly and the first supporting plate and used for supporting the sensor.

Optionally, the second supporting plate is fixedly connected with the lower shell through an elastic arm.

Optionally, comprising: the alarm is connected with the controller; the controller is configured to: when the sensor detects that the parameters of the cell assembly related to the deformation quantity meet preset conditions, an alarm signal is output to trigger the alarm to alarm.

Optionally, the sensor comprises a detection terminal; the controller is configured to: acquiring the voltage of the detection terminal; when voltage is less than or equal to first preset voltage, the output makes the control signal of switch disconnection is in order to cut off the electric core subassembly with electric connection between the battery package interface.

Optionally, the sensor comprises a detection terminal; the controller is configured to: acquiring the voltage of the detection terminal; and when the voltage is greater than a second preset voltage, outputting a control signal for switching off the switch so as to cut off the electric connection between the electric core assembly and the battery pack interface.

Optionally, the cell elastic member is formed around the cell assembly in a glue injection manner.

A power tool system, comprising: the electric tool comprises a functional piece and a motor for driving the functional piece to act; a battery pack for supplying electric power to the electric tool; the battery pack includes: a housing comprising an upper housing and a lower housing assembled at an interface to form an internal cavity; an electrical core assembly disposed within the internal cavity; the battery cell assembly comprises a plurality of non-cylindrical battery cell units; the battery cell units are arranged in a stacked manner; a cell elastic member disposed around the cell assembly to seal the cell assembly; the battery pack interface is electrically connected with the electric core assembly and is connected with the electric tool to provide electric energy for the electric tool; the battery pack interface is connected with the battery pack interface through a power supply line; the sensor is positioned on one side of the electric core elastic piece and used for detecting parameters related to the deformation quantity of the electric core assembly; the power tool system further includes: the switch is arranged on the discharge loop; a controller configured to: and when the sensor detects that the parameter of the cell assembly related to the deformation quantity meets a preset condition, outputting a control signal for disconnecting the switch so as to cut off the discharge loop.

A charging assembly, comprising: a charger including a charging circuit; a battery pack for supplying electric power to the electric tool; the battery pack includes: a housing comprising an upper housing and a lower housing assembled at an interface to form an internal cavity; an electrical core assembly disposed within the internal cavity; the battery cell assembly comprises a plurality of non-cylindrical battery cell units; the battery cell units are arranged in a stacked manner; a cell elastic member disposed around the cell assembly to seal the cell assembly; the battery pack interface is electrically connected with the electric core assembly and is connected with the charging circuit to provide electric energy for the electric core assembly; the battery pack assembly, the battery pack interface and the charging circuit form a charging loop; the sensor is positioned on one side of the electric core elastic piece and used for detecting parameters related to the deformation quantity of the electric core assembly; the charging assembly further comprises: a switch disposed on the charging circuit; a controller configured to: and when the sensor detects that the parameter of the cell assembly related to the deformation quantity meets a preset condition, outputting a control signal for switching off the switch so as to cut off the charging loop.

The battery pack and the electric tool adopting the battery pack have the advantages that the potential safety hazard of explosion caused by internal deformation and deformation of the battery pack is reduced, and the safety and the reliability of the battery pack are effectively improved.

Drawings

FIG. 1 is a schematic diagram of a power tool system provided in accordance with an embodiment;

FIG. 2 is a perspective view of the power tool of FIG. 1;

FIG. 3 is a block diagram of a battery pack according to an embodiment;

fig. 4 is a schematic structural view of the battery pack shown in fig. 3 with the upper case removed;

fig. 5 is a schematic diagram of the internal structure of the battery pack shown in fig. 3 with the casing and the cell elastic member removed;

fig. 6 is a schematic diagram of the internal structure of the cell assembly shown in fig. 3, which includes a part of the cell elastic member;

fig. 7 is a schematic view of the internal structure between the lower case and the first support plate according to the first embodiment;

fig. 8 is a schematic view of the internal structure between the lower case and the first support plate according to the second embodiment;

fig. 9 is a block diagram of a protection circuit for a battery pack according to the first embodiment;

fig. 10 is a block diagram of a protection circuit for a battery pack of the second embodiment;

fig. 11 is a block diagram of a protection circuit for a power tool system of the first embodiment;

fig. 12 is a block diagram of a protection circuit for a charging combination according to the first embodiment.

Detailed Description

The invention is described in detail below with reference to the figures and the embodiments.

Fig. 1 shows a power tool system 100 including a power tool 10 and a battery pack 20 that can adapt the power tool 10 to power the power tool 10. In fig. 1, the power tool 10 is an impact wrench. While the present embodiment relates to an impact wrench, it should be understood that the present application is not limited to the disclosed embodiments, but is applicable to other types of power tools 10, such as garden-type tools like lawn mowers, pruners, blowers, chain saws; the tool may be a torque output tool such as an electric drill or an electric hammer, a saw tool such as an electric circular saw, a jig saw or a reciprocating saw, or a grinding tool such as an angle grinder or a sander.

Referring to fig. 2, the electric power tool 10 includes a tool body 11, and a tool interface 12 and a tool engagement portion 13 provided on the tool body 11.

The tool body 11 includes a motor 111, an output shaft 112, and an impact mechanism 113. The output shaft 112 is driven by the motor 111; the impact mechanism 113 is connected to the motor 111 and the output shaft 112, and the impact mechanism 113 is driven by the motor 111 and applies an impact force to the output shaft 112. The power tool 10 body also includes a handle 114 that can be grasped by a user to operate the power tool 10. A trigger switch 115 is also provided on the handle, the trigger switch 115 being adapted to be actuated by a user of the power tool 10 to start or stop operation of the motor 111. In addition, the power tool 10 is further provided with a tool interface 12 and a tool fitting portion 13 at the lower end of the handle 114 for detachably connecting with the battery pack 20. In some embodiments, the tool engaging portion 13 is configured such that the battery pack 20 can be detached therefrom when the user slides the battery pack 20 toward the front of the main body of the power tool 10.

In the following description, the vertical and longitudinal directions are described with reference to the directions shown in fig. 3.

Referring to fig. 3 to 5, the battery pack 20 includes a housing 23, a battery pack assembly 24, a battery pack coupling part 22, and a battery pack interface 21. The voltage of the battery pack 20 is usually 10.8V, 24V, 36V, 48V, 56V, or 80V, the capacity of the battery pack 20 is 5Ah or more, and the capacity of the battery pack is 9Ah or more. The battery pack 20 is provided with a battery pack interface 21 and a battery pack coupling portion 22. The battery pack interface 21 is adapted to the tool interface 12 to power the power tool 10, and the battery pack interface 21 is further adapted to a charger to enable the charger to charge the battery pack 20. The battery pack coupling portion 22 can be detachably connected to the tool engaging portion 13 or the charger, so that the battery pack 20 can supply power to the power tool 10 or the charger can charge the battery pack assembly 24.

The housing 23 includes an upper housing 231 and a lower housing 232 assembled at an interface to form an inner cavity; the inner cavity formed by the assembly of the upper housing 231 and the lower housing 232 is used for fixing and accommodating the electric core assembly 24.

An electrical core assembly 24 is disposed within the internal cavity formed by the housing 23. The cell assembly 24 includes a plurality of cell units 241. The cell unit 241 includes a cell tab 242, and the cell tab 242 further includes a cell unit positive electrode 2421 and a cell unit negative electrode 2422, and is configured to output electric energy of the cell unit 241 or input electric energy to charge the cell unit 241. The cell assembly 24 further comprises a cell assembly positive terminal and a cell assembly negative terminal, and the cell assembly positive terminal and the cell assembly negative terminal are used for outputting electric energy of the cell assembly 24 or inputting electric energy to charge the cell assembly 24. Wherein, the positive terminal of the battery core component is connected in series between at least one positive electrode of the battery cell unit and the positive terminal of the battery pack; the negative terminal of the cell assembly is connected in series between at least one negative electrode of the cell unit and the negative terminal of the battery pack. A plurality of cell units 241 are typically connected in series, in parallel, or in a combination of series and parallel to form a cell assembly 24. The voltage of the single cell unit 241 is 4.2V. In some embodiments, the cell unit 241 is a cylindrical structure, such as 18650 type battery. In other embodiments, the battery cell units 241 are in a flat bag-shaped structure, a plurality of battery cell units 241 are stacked and arranged along the vertical direction, and the battery cell units 241 may also be bent into an arc-shaped structure, such as a soft-package battery pack. The battery cell unit 241 further includes a battery cell unit 241 casing, a cylindrical battery generally adopts a steel shell as the battery cell unit 241 casing, and a soft package battery generally adopts an aluminum plastic film as the battery cell unit 241 casing. It is to be understood that the present application is not limited to the disclosed embodiments, and the structure of the cell unit 241 is not limited herein.

The battery pack interface 21 is formed on an upper surface of the housing 23, and is electrically connected to at least the electric core assembly 24 for establishing physical and electrical connection with the electric tool, and specifically, the battery pack interface 21 is formed on an upper surface of the upper housing 231. In some embodiments, the battery pack interface 21 includes a power positive interface 211, a power negative interface 212, and a power communication interface 213. The battery pack 20 outputs electric energy through the power supply positive interface 211 and the power supply negative interface 212; the battery pack 20 communicates with an attached power tool or charger through the power communication interface 213. In one specific embodiment, the housing is provided with 2 power positive interfaces 211 and 2 power negative interfaces 212, it being understood that the housing 23 may be provided with more or less power positive interfaces 211 and power negative interfaces 212 depending on the electrical characteristics of the battery pack.

The battery pack further includes a first support plate 25, a main circuit board 26, and a terminal assembly 27.

The first support plate 25 is located at an upper side of the lower case 232, and forms an accommodating space with the lower case 232 to accommodate the electric core assembly 24. The first support plate 25 is detachably coupled with the lower case 232 to form a receiving space to receive the electric core assembly 24. Similarly, the first support plate 25 and the upper housing 231 form an accommodating space for accommodating the main circuit board 26, the terminal assembly 27, and the like. Specifically, the first support plate 25 has a plate-like structure.

The terminal assembly 27 includes a plurality of battery pack terminals and a terminal support 271. The terminal supporting base 271 is used for accommodating and fixing a plurality of battery pack terminals on the first supporting plate 25. The plurality of battery pack terminals further include a battery pack positive terminal 272, a battery pack negative terminal 273, and a battery pack communication terminal 274. The battery pack positive terminal 272 is electrically connected with the cell assembly positive terminal, i.e. the positive electrode of at least one cell unit, and is located in the power supply positive interface 211; the negative terminal 273 of the battery pack and the negative terminal of the cell assembly, i.e. at least one cell unit, are electrically connected and are located in the negative interface 212 of the power supply. The battery pack positive terminal 272 and the battery pack negative terminal 273 are configured to cooperate with the tool terminal of the electric tool 10 to output the electric power of the battery pack assembly 24 to the electric tool 10, and specifically, the electric power of the battery pack assembly 24 passes through the battery pack positive terminal, the battery pack positive terminal 272 to the tool interface 12 of the electric tool, the motor 111, and passes through the battery pack negative terminal 273, and the battery pack negative terminal returns to the battery pack assembly 24, therefore, the battery pack assembly 24, the plurality of battery pack terminals in the battery pack interface, and the motor 111 of the electric tool constitute a discharging loop, and the motor 111 consumes the electric power of the battery pack assembly 24 through the discharging loop. In addition, a battery pack communication terminal 274 is located in the power supply communication interface 213 for communication with the power tool 10 or the charger that is accessed. As a specific embodiment, the battery pack terminals respectively clamp the tool terminals by elastic force from both sides in the left-right direction, and therefore, the tool terminals of the electric power tool are inserted into the battery pack terminals while being guided by the battery pack interface during the installation of the battery pack to the electric power tool, so that the tool terminals are clamped by the battery pack terminals, thereby electrically connecting the electric power tool 10 with the battery pack 20.

And the main circuit board 26 is arranged on the upper side of the first support plate 25, is connected between the electric core assembly 24 and the battery pack interface 21 in series, and is used for acquiring electric signals related to the battery pack 20. In some embodiments, the main circuit board 26 is connected in series between the battery pack assembly 24 and the battery pack communication terminal 274 for transmitting battery pack information to the power tool 10 attached to the battery pack 20 through the battery pack communication terminal 274. The battery pack information includes: the discharge current of the battery pack, the temperature of the battery cell assembly 24 and/or the cell unit 241, the voltage of the cell unit 241, the internal resistance value of the cell unit 241, and the like. Typically, the battery pack information is detected by a sensor, and therefore, the battery pack 20 further includes a detection sensor. The number of the detection sensors may be one or more. In some embodiments, the detection sensor may be a temperature sensor, and the temperature sensor is disposed on a surface of the cell assembly 24 or a surface of the cell unit 241, and the temperature sensor may be a thermistor. The detection sensor may also be a voltage sensor, and is configured to detect a voltage of the cell unit 241.

Referring to fig. 5, the battery pack 20 further includes a detection circuit board 28, and the detection sensor is integrated on the detection circuit board 28, and for convenience of detection, the detection circuit board 28 is disposed on one side of the cell assembly where the cell tab 242 is located, that is, on one side of the cell assembly 24 where the cell positive electrode 2421 and the cell negative electrode 2422 are located. It will be appreciated that the battery pack 20 may also include other types of sensors, such that the detection circuit board 28 may collect battery pack information via the various sensors, while communicating the collected battery pack information to the main circuit board 26 and to the attached power tool 10 or charger via the battery pack communication terminals 274. In some embodiments, the cell tabs 242, i.e., the cell unit positive electrodes 2421 and the cell unit negative electrodes 2422, are disposed on a front end surface or a rear end surface of the cell unit 241.

Referring to fig. 6, the battery pack 20 further includes a cell elastic member 201, and the cell elastic member 201 is located on at least one side of the cell assembly 24 to protect the cell assembly 24. The cell assembly 24 has an upper surface and a lower surface, a front end surface and a rear end surface provided between the upper surface and the lower surface, and a left side surface and a right side surface provided on both sides of the first end surface. Wherein the front end face and the rear end face are oppositely arranged. In some embodiments, the cell elastic member 201 is disposed around the cell assembly 24, that is, the cell elastic member 201 is disposed around the upper surface, the lower surface, the front end surface, the rear end surface, the left side surface and the right side surface of the cell assembly 24 for sealing the cell assembly 24 to achieve functions of water proofing, dust proofing, and the like. In other embodiments, the cell elastic members 201 are disposed at two ends of the cell assembly, and at least a portion of the cell elastic members 201 encapsulate the tabs, so as to fix the tabs in a covering manner. In this way, the cell elastic member 201 is used to protect the cell assembly 24, and prevent the cell units 241 from being displaced relatively to each other due to jolting or vibration, so as to avoid the occurrence of squeezing or twisting of the cell units 241 or the tabs. Therefore, the battery cell elastic member 201 can improve the anti-falling and shock-absorbing performance of the battery pack 20, and further improve the reliability of the battery pack 20; and the cell elastic member 201 is an elastic member capable of better adapting to the expansion property of the battery pack 20. Moreover, the cell elastic member 201 can also improve the heat dissipation performance of the battery pack 20.

In some embodiments, the cell elastic member 201 fixes the cell assembly 24 and the detection circuit board 28 and other connecting wires in an enveloping manner. In order to enable the cell assembly 24 to output or input electric energy, the positive lead-out piece 243 and the negative lead-out piece 244 of the cell assembly 24 extend out from the inside of the cell elastic member 201 and protrude out of the cell elastic member 201, and are electrically connected with the positive terminal 272 and the negative terminal 273 of the battery pack, respectively. In some embodiments, the cell elastic member 201 is formed around the cell assembly 24 by injecting glue. Specifically, place electric core subassembly 24 in lower casing 232, adopt the injecting glue mode to form electric core elastic component 201 in order to realize functions such as waterproof, dustproof in electric core subassembly 24 sealed at whole electric core subassembly 24's surface.

Referring to fig. 7, the battery pack 20 further includes a deformation sensor 202, and the deformation sensor 202 is disposed on one side of the cell elastic member 201 and is used for detecting a parameter related to a deformation amount of the cell assembly 24. Specifically, the deformation sensor 202 is located on the upper side of the cell elastic member 201 and is spaced from the upper surface of the cell elastic member 201 by a predetermined distance. The deformation sensor 202 is disposed between the cell elastic member 201 and the first support plate 25, and in some embodiments, the deformation sensor 202 is specifically disposed on the lower surface of the first support plate 25, and is spaced from the upper surface of the cell elastic member 201 by 1 to 6 mm, that is, the preset distance is greater than or equal to 1 mm and less than or equal to 6 mm.

In this embodiment, the deformation sensor 202 is connected to the main circuit board 26 through the first connection line 203 to output a sensing signal of the deformation sensor 202 to the main circuit board 26. In one embodiment, the deformation sensor 202 is a pressure sensor, and the deformation sensor 202 is capable of outputting a sensing signal when receiving a pressure. Specifically, referring to fig. 5, when the cell assembly 24 deforms, for example, the cell assembly 24 expands to increase the first thickness H1, the cell elastic member 201 deforms accordingly and protrudes upwards to contact the deformation sensor 202, and the deformation sensor 202 senses the pressure from the cell elastic member 201 to output a sensing signal, and transmits the sensing signal to the main circuit board 26 through the first connection line. Like this, deformation sensor 202 and first connecting wire set up outside electric core elastic component 201, make things convenient for maintenance and replacement when deformation sensor 202 breaks down.

On the one hand, because electric core subassembly 24 has certain deformation when normally working, it has to predetermine between the deformation that the distance can guarantee electric core subassembly 24 normal working to reserve between deformation sensor 202 and electric core elastic component 201 to improve deformation sensor 202's reliability, reduce the probability of spurious triggering. On the other hand, because electric core elastic component 201 surrounds electric core subassembly 24 and forms an inclosed cavity, the temperature variation of battery package during operation may lead to the air inflation in the inclosed cavity, causes the atmospheric pressure increase in the inclosed cavity, consequently, set up deformation sensor 202 in the electric core elastic component 201 outside, can also avoid the influence that the inclosed cavity that electric core elastic component 201 formed detected the deformation of electric core subassembly 24, the reliability of deformation sensor 202 has also been improved to the security and the reliability of battery package have been improved. In addition, first backup pad 25 sets up between electric core subassembly 24 and main circuit board 26, even like this electric core subassembly 24 takes place deformation, first backup pad 25 can effectual hindrance electric core subassembly 24 deformation, protects main circuit board 26, prevents electric core subassembly 24 deformation and damages main circuit board 26.

In other embodiments, referring to fig. 8, the battery pack 20 further includes a second support plate 204, and the second support plate 204 includes an elastic plate having a certain elastic coefficient. The second support plate 204 is disposed between the core assembly 24 and the first support plate 25 to support the deformation sensor 202. In this embodiment, the second supporting plate 204 is fixedly connected to the lower housing 232 through an elastic arm having a certain elastic coefficient, and the second supporting plate 204 further includes a plurality of elastic arms detachably connected to the lower housing 232 through screws. It is understood that the second support plate 204 can be made of an elastic material, and is not limited thereto, as long as it can deform along with the deformation of the core assembly 24. Specifically, the deformation sensor 202 is disposed on the upper surface of the second support plate 204, and is spaced 1-6 mm from the upper surface of the cell elastic member 201 covering the outer surface of the cell assembly 24.

In this embodiment, the deformation sensor 202 is connected to the detection circuit board 28 through a second connection line 205 to output a sensing signal of the deformation sensor 202 to the detection circuit board 28. Specifically, when the cell assembly 24 deforms, for example, the cell assembly 24 expands to increase the first thickness H1, the cell elastic member 201 deforms and protrudes upward to contact the second support plate 204, and the deformation sensor 202 disposed on the second support plate 204 also protrudes upward to contact the first support plate 25, so that the deformation sensor 202 senses the pressure from the first support plate 25 and the second support plate 204 to output a sensing signal, and transmits the sensing signal to the detection circuit board 28 through the second connection line 205, and the detection circuit board 28 collects the sensing signal and transmits the sensing signal to the main circuit board 26. The specific shapes of the first connection line 203 and the second connection line 205 may be set according to the specific structure of the battery pack, and are not limited herein.

Fig. 9 shows a block diagram of a protection circuit of the battery pack. As shown in fig. 9, the battery pack protection circuit 30 includes: the battery pack 31, the switch 32, the controller 33, the battery pack positive terminal 341, the battery pack negative terminal 342, and the deformation sensor 33. Wherein, the battery pack positive terminal 341 and the battery pack negative terminal 342 are disposed in the battery pack interface 34, and the electric core assembly 31 further includes an electric core assembly positive terminal 311 and an electric core assembly negative terminal 312.

And a switch 32 connected between the battery pack assembly 31 and the battery pack interface 34 for turning on or off the electrical connection between the battery pack assembly 31 and the battery pack interface 34. The on and off of the switch 32 is controlled by a controller 33. In some embodiments, a switch is provided between the battery pack positive terminal 311 and the battery pack positive terminal 341; in other embodiments, a switch is provided between the negative terminal 312 of the battery pack and the negative terminal 342 of the battery pack. Specifically, the switch 32 is disposed on the circuit board, and the switch 32 may be a metal oxide semiconductor transistor, and may also be an electronic switch such as an insulated gate bipolar transistor or a relay.

The controller 33 is connected to the deformation sensor 35, and configured to output a control signal for turning off the switch 32 to cut off the electrical connection between the cell assembly 31 and the battery pack interface 34 when the deformation sensor 35 detects that the parameter related to the deformation of the cell assembly 31 satisfies a preset condition. The strain sensor 35 includes at least a detection terminal 351, and the detection terminal 351 is connected to the controller 33. In some embodiments, the parameter related to the deformation amount of the deformation sensor 35 and the electric core assembly 31 is a voltage parameter, and specifically, after the deformation sensor 35 is powered on, the output voltage of the detection terminal 351 changes continuously along with the change of the pressure applied to the deformation sensor 35. Therefore, the controller 33 is specifically configured to obtain the voltage of the detection terminal 351, and output a control signal for turning off the switch 32 to cut off the electrical connection between the cell assembly 31 and the battery pack interface 34 when the voltage of the detection terminal 351 is less than or equal to a first preset voltage. In this embodiment, since the resistance of the deformation sensor 35 is gradually increased along with the increasing of the pressure applied to the electric core assembly 31, the voltage of the detection terminal 351 is continuously decreased along with the increasing of the pressure applied to the deformation sensor 35 until the voltage is decreased to the first preset voltage, the controller 33 determines that the electric core assembly 31 is deformed at this time to disconnect the switch 32, so as to disconnect the electric connection between the electric core assembly 31 and the battery pack interface 21, thereby protecting the safety of the battery pack. Specifically, the deformation sensor 35 may be one of a strain gauge pressure sensor, a piezoresistive pressure sensor, a capacitive pressure sensor, a piezoelectric pressure sensor, an inductive pressure sensor or a hall pressure sensor, and thus, the parameter related to the deformation of the electric core assembly 31 acquired by the controller 33 may also be a resistance value, a current value, an inductance value, etc. according to the selected difference of the deformation sensor 35, which is not limited herein. It is understood that the present application includes, but is not limited to, the disclosed embodiments, and the preset conditions for the controller 33 to turn the switch 321 on or off may be different according to the specific circuit of the deformation sensor 35. For example, the controller 33 may be further configured to output a control signal for turning off the switch 32 to cut off the electrical connection between the electric core assembly 31 and the battery pack interface 21 when the voltage of the detection terminal 351 is greater than or equal to a first preset voltage, so as to protect the safety of the battery pack.

In other embodiments, referring to fig. 10, the battery pack protection circuit 40 includes an alarm 46, and the alarm 46 can be triggered. The controller 43 is configured to output an alarm signal to trigger the alarm 46 to alarm when the deformation sensor 45 detects that the parameter of the electric core assembly 41 related to the deformation quantity meets the preset condition. The deformation sensor 45 at least comprises a detection terminal 451, the detection terminal 451 is connected with the controller 43, and the controller 43 is specifically configured to obtain a voltage of the detection terminal 451, and output an alarm signal to trigger the alarm 46 to alarm when the voltage is less than or equal to a first preset voltage. In this embodiment, since the resistance of the deformation sensor 45 is gradually increased along with the pressure applied to the electric core assembly 41, the voltage of the detection terminal 451 is continuously decreased along with the increase of the pressure applied to the deformation sensor 45 until the voltage is reduced to the first preset voltage, the controller 43 determines that the electric core assembly 41 is deformed at the moment and sends out an alarm signal to trigger the alarm 46 to alarm. The alarm 46 may be a buzzer, and the buzzer triggers an alarm to generate a buzzer to remind a user that a potential safety hazard currently exists in the battery pack. The alarm 46 may also be other electronic devices, such as an LED lamp, which can be triggered to flash to alert a user that there is a safety risk when the battery pack assembly 41 deforms.

In order to further improve the reliability of the strain sensor 45, the controller 43 needs to determine whether the strain sensor 45 is reliable before determining whether the electric core assembly 41 is deformed. Accordingly, the controller 43 is configured to: acquiring a voltage of the detection terminal 451; when the voltage is greater than a second preset voltage, a control signal for switching off the switch is output to cut off the electrical connection between the battery pack interface 44 and the battery pack assembly 41. In this embodiment, if the deformation sensor 45 is reliable, the voltage should be less than or equal to a second preset voltage; if the voltage of the detection terminal 451 is greater than the second preset voltage, it indicates that the deformation sensor 45 is open-circuited, thereby determining that the deformation sensor 45 is failed. To ensure the safety of the battery pack, the controller 43 opens the switch, thereby cutting off the electrical connection between the core assembly 41 and the battery pack interface 44. On the contrary, if the voltage of the detection terminal 451 is less than or equal to the second preset voltage, it indicates that the deformation sensor 45 is reliable, and it is continuously determined whether the voltage is less than or equal to the first preset voltage to determine whether the core assembly 41 is deformed. The first preset voltage is smaller than the second preset voltage.

In other embodiments, the switch of the battery pack protection circuit is disposed within the power tool system, particularly on the discharge circuit. Fig. 11 shows a block diagram of a protection circuit of a power tool system according to an embodiment, and referring to fig. 11, the power tool system includes a power tool 50 and a battery pack 60. The battery pack 60 is attached to the electric power tool 50, and the battery pack positive terminal 641 and the battery pack negative terminal 642 are mated with the tool positive terminal 531 and the tool negative terminal 532 of the electric power tool to output electric power of the core assembly 61 to the electric power tool 50, and the battery pack communication terminal and the tool communication terminal are connected to communicate with the electric power tool. In the present embodiment, the switch 51 is disposed on a discharge circuit formed by the battery pack assembly 61, the battery pack interface 64, and the motor 52 of the electric tool, and is at least used for turning on or off the electrical connection between the battery pack and the motor 52 of the electric tool. The on and off of the switch 51 is also controlled by the controller 63, and specifically, the controller 63 transmits a control signal for turning off the switch 51 through the battery pack communication terminal. The controller 63 is configured to output a control signal for opening the switch 51 to cut off the discharge circuit when the deformation sensor 62 detects that the parameter of the electric core assembly 61 related to the deformation quantity satisfies a preset condition, so as to protect the safety of the electric tool system. The deformation sensor 62 at least includes a detection terminal 621, the detection terminal 621 is connected to the controller 63, and the controller 63 is specifically configured to obtain a voltage of the detection terminal 621, and output a control signal for turning off the switch 51 to cut off the discharge loop when the voltage is less than or equal to a first preset voltage. Because the resistance of deformation sensor 62 reduces along with the continuous deformation pressure that receives of battery pack 61 increases gradually, consequently the voltage of detection terminal 621 constantly reduces along with the increase of the pressure that receives of deformation sensor 62, and when the voltage dropped to first preset voltage, controller 63 judged that battery pack 61 took place deformation this moment and made the switch 51 disconnection to cut off the discharge circuit, the safety of protection battery package. It should be noted that although the present embodiment discloses the switch 51 disposed in the power tool, the switch 51 may also be disposed in the battery pack, and is not limited herein.

In order to further improve the reliability of the strain sensor 62, the controller 63 determines whether the strain sensor 62 is reliable before determining whether the electric core assembly 61 is deformed. The controller 63 is configured to: acquiring the voltage of the detection terminal 621; and outputting a control signal for turning off the switch 51 to cut off the discharging loop when the voltage is greater than a second preset voltage. In this embodiment, if the deformation sensor 62 is reliable, the voltage should be less than or equal to a second predetermined voltage; if the voltage of the detection terminal 621 is greater than the second preset voltage, it indicates that the deformation sensor 62 is open-circuited, so as to determine that the deformation sensor 62 is failed, and in order to ensure the safety of the battery pack, the controller 63 opens the switch 51, so as to cut off the discharge circuit. On the contrary, if the voltage of the detection terminal 621 is less than or equal to the second preset voltage, it indicates that the deformation sensor 62 is reliable, and it is continuously determined whether the voltage is less than or equal to the first preset voltage to determine whether the core assembly 61 is deformed. The first preset voltage is smaller than the second preset voltage.

Fig. 12 shows a block diagram of a protection circuit for a charging set according to an embodiment, and referring to fig. 12, the charging set includes a battery pack 60 and a charger 80.

The charger 80 is used to charge the battery pack. Illustratively, the charger 80 includes a charging circuit 82 and a dc output interface 83, and the charging circuit 82 includes an ac input interface and a dc-to-ac conversion circuit. Specifically, the ac input interface is used for accessing ac, and in some embodiments, the ac input interface is connected to a power plug, and the power plug is plugged into an ac electrical outlet to access ac commercial power. The value range of the alternating current accessed by the alternating current input interface is 110V-130V or 210V-230V. The alternating current-direct current conversion circuit is electrically connected with the alternating current input interface so as to convert alternating current into direct current; the dc output interface 83 is electrically connected to the ac/dc conversion circuit to output dc power. The dc output interface 83 also includes a charger positive terminal 831 and a charger negative terminal 832. The charger positive terminal 831 and the charger negative terminal 832 cooperate with the pack positive terminal 641 and the pack negative terminal 642 to provide power to the electric core assembly 61, and the charger communication terminal 833 and the pack communication terminal 643 are connected to communicate with the battery pack. In the present embodiment, the switch 81 is disposed on the charging circuit formed by the battery cell assembly 61, the battery pack interface 64 and the charging circuit 82, and is at least used for turning on or off the electrical connection between the battery pack and the charging circuit 82. The on and off of the switch is also controlled by the controller 63, and specifically, the controller 63 transmits a control signal for turning off the switch through the battery pack communication terminal. The controller 63 is configured to output a control signal for opening the switch to cut off the charging loop to protect the safety of the charging combination when the deformation sensor 62 detects that the parameter of the cell assembly 61 related to the deformation quantity meets a preset condition. The deformation sensor 62 at least includes a detection terminal 621, the detection terminal 621 is connected to the controller 63, and the controller 63 is specifically configured to obtain a voltage of the detection terminal 621, and output a control signal for turning off the switch 81 to cut off the charging loop when the voltage is less than or equal to a first preset voltage. Because the resistance of deformation sensor 62 reduces along with the increase of the pressure that receives, therefore the voltage of detection terminal 621 constantly reduces along with the increase of the pressure that receives of deformation sensor 62, until when voltage reduces to first preset voltage, judge that electric core subassembly 61 takes place deformation this moment, controller 63 makes switch 81 break off to cut off charging circuit, the safety of protection battery package. It should be noted that although the present embodiment discloses the switch disposed in the charger 80, the switch may also be disposed in the battery pack, and is not limited thereto.

In order to further improve the reliability of the strain sensor 62, the controller 63 determines whether the strain sensor 62 is reliable before determining whether the electric core assembly 61 is deformed. The controller 63 is configured to: acquiring the voltage of the detection terminal 621; and outputting a control signal for opening the switch 81 to cut off the charging loop when the voltage is greater than the second preset voltage. In the present embodiment, if the deformation sensor 62 is reliable, the voltage should be less than or equal to the second predetermined voltage; if the voltage of the detection terminal 621 is greater than the second preset voltage, it indicates that the deformation sensor 62 is broken, and thus it is determined that the deformation sensor 62 is failed, and in order to ensure the safety of the battery pack, the controller 63 turns off the switch 81, and thus cuts off the charging circuit. On the contrary, if the voltage of the detection terminal 621 is less than or equal to the second preset voltage, it indicates that the deformation sensor 62 is reliable, and it is continuously determined whether the voltage is less than or equal to the first preset voltage to determine whether the core assembly 61 is deformed. The first preset voltage is smaller than the second preset voltage.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalents or equivalent changes fall within the protection scope of the present invention.

Claims

1. A battery pack, comprising:

a housing comprising an upper housing and a lower housing assembled at an interface to form an internal cavity;

an electrical core assembly disposed within the internal cavity; the battery cell assembly comprises a plurality of non-cylindrical battery cell units; the battery cell units are arranged in a stacked manner;

the battery cell elastic piece is positioned on at least one side of the battery cell assembly to protect the battery cell assembly;

the battery pack interface is at least electrically connected with the electric core assembly;

a switch connected between the battery pack assembly and the battery pack interface;

the deformation sensor is positioned on one side of the electric core elastic piece and used for detecting parameters related to the deformation of the electric core assembly;

a controller configured to:

when the deformation sensor detects that the parameters related to the electric core assembly and the deformation quantity meet the preset conditions, the control signal for switching off the switch is output to cut off the electric connection between the electric core assembly and the battery pack interface.

2. The battery pack according to claim 1,

the cell elastic piece is arranged around the cell assembly to seal the cell assembly;

the deformation sensor is located the upside of electric core elastic component and with electric core elastic component upper surface interval has the distance of predetermineeing.

3. The battery pack according to claim 2,

the preset distance ranges from greater than or equal to 1 mm to less than or equal to 6 mm.

4. The battery pack according to claim 2,

the method comprises the following steps:

the first supporting plate is positioned on the upper side of the lower shell, and an accommodating space for accommodating the electric core assembly is formed between the first supporting plate and the lower shell;

the deformation sensor is arranged on the lower surface of the first supporting plate.

5. The battery pack according to claim 2,

the method comprises the following steps:

the first support plate is positioned on the upper side of the lower shell, and an accommodating space for accommodating the electric core assembly is formed between the first support plate and the lower shell;

the second supporting plate comprises an elastic plate with an elastic coefficient, and is arranged between the electric core assembly and the first supporting plate and used for supporting the deformation sensor.

6. The battery pack according to claim 5,

the second supporting plate is fixedly connected with the lower shell through an elastic arm.

7. The battery pack according to claim 1,

the method comprises the following steps:

the alarm is connected with the controller;

the controller is configured to:

and when the deformation sensor detects that the parameters of the electric core assembly related to the deformation quantity meet the preset conditions, outputting an alarm signal to trigger the alarm to alarm.

8. The battery pack according to claim 1,

the deformation sensor includes a detection terminal;

the controller is configured to:

acquiring the voltage of the detection terminal;

when the voltage is less than or equal to a first preset voltage, outputting a control signal for switching off the switch so as to cut off the electric connection between the electric core assembly and the battery pack interface.

9. The battery pack according to claim 1,

the deformation sensor includes a detection terminal;

the controller is configured to:

acquiring the voltage of the detection terminal;

and when the voltage is greater than a second preset voltage, outputting a control signal for switching off the switch so as to cut off the electric connection between the electric core assembly and the battery pack interface.

10. The battery pack according to claim 1,

the battery cell elastic piece is formed around the battery cell assembly in a glue injection mode.

11. A power tool system, comprising:

the electric tool comprises an output shaft and a motor for driving the output shaft to act;

a battery pack for supplying electric power to the electric tool;

the battery pack includes:

the battery pack interface is electrically connected with the electric core assembly and is connected with the electric tool to provide electric energy for the electric tool;

the battery pack assembly, the battery pack interface and the motor form a discharge loop, and the motor consumes the electric energy of the battery pack assembly;

the deformation sensor is positioned on one side of the electric core elastic piece and used for detecting parameters related to the deformation quantity of the electric core assembly;

the power tool system further includes:

a switch disposed on the discharge circuit;

a controller configured to:

and when the deformation sensor detects that the parameters of the cell assembly related to the deformation meet preset conditions, outputting a control signal for switching off the switch to cut off the discharge loop.

12. A charging assembly, comprising:

a charger including a charging circuit;

a battery pack for supplying electric power to the electric tool;

the battery pack includes:

the battery pack interface is electrically connected with the battery cell assembly and is connected with the charging circuit to provide electric energy for the battery cell assembly;

the battery pack interface is connected with the battery pack interface and the charging circuit;

the charging assembly further comprises:

a switch disposed on the charging circuit;

a controller configured to:

and outputting a control signal for switching off the switch to cut off the charging loop when the deformation sensor detects that the parameters of the cell assembly related to the deformation quantity meet the preset conditions.