Battery pack

Abstract

The utility model discloses a battery pack, particularly relates to a battery pack of an electric tool, and solves the problem that a circuit board of the battery pack is severely heated due to relatively large current during charging and discharging of the existing electric tool. The utility model provides a battery pack which comprises a shell, a plurality of batteries arranged in the shell and a circuit board arranged on the shell, electrode plates electrically connected with the batteries are arranged on the shell, the electrode plates comprise a positive electrode plate and a negative electrode plate, and the battery pack further comprises a current-carrying plate arranged at the upper end of the circuit board, the current-carrying sheet comprises a positive current-carrying sheet connected with the positive electrode sheet and a load current-carrying sheet connected with the negative electrode sheet, a plug-in terminal is integrally formed on the current-carrying sheet, and the plug-in terminal is used for plugging an electric device for inputting or outputting current. According to the technical scheme of the utility model, the current-carrying sheet is adopted to replace a current layer for transmitting current on the circuit board, so that large current is prevented from passing through the circuit board, and the heating of the circuit board is reduced.

Description

Technical Field

[0001] The utility model relates to the field of battery packs, in particular to a battery pack for an electric tool. Background Art

[0002] Considering portability and scope of use, more and more power tools use battery packs as their power source. With the continuous development of battery technology, the charging and discharging current of battery packs is also increasing.

[0003] The battery pack for electric tools usually has a current layer for transmitting current in the circuit board of the battery pack. The circuit board generates a lot of heat under high current, which will affect the working state of each component on the circuit board. At the same time, it is difficult for the circuit board to dissipate heat, and heat is easy to accumulate on it, which will also cause the temperature of the battery close to the circuit board to rise, thus affecting the working performance and service life of the battery. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and propose a battery pack to solve the problem that the circuit board of the prior battery pack generates a large amount of heat under a large current condition.

[0005] In order to achieve the above technical objectives, the utility model proposes a battery pack, including a shell, a plurality of batteries installed in the shell and a circuit board installed on the shell, the shell is provided with electrode sheets electrically connected to the batteries, the electrode sheets include positive electrode sheets and negative electrode sheets, and also includes a current-carrying sheet installed on the upper end of the circuit board, the current-carrying sheet includes a positive current-carrying sheet connected to the positive electrode sheet and a load current sheet connected to the negative electrode sheet, the current-carrying sheet is integrally formed with a plug-in terminal, and the plug-in terminal is used to plug in an electrical device that inputs or outputs current.

[0006] Preferably, a mounting seat insulated from the circuit board is fixed at the upper end of the circuit board, and a carrier chip mounting position is provided on the mounting seat. The carrier chip is placed in the carrier chip mounting position, and the carrier chip mounting position limits the carrier chip on a side away from the plug-in terminal.

[0007] Preferably, a signal terminal is also installed on the circuit board, and a signal terminal mounting position insulated from the carrier chip mounting position is provided on the mounting seat. The signal terminal is placed in the signal terminal mounting position, and the signal terminal includes a plug-in portion for plugging in a signal connector of an electrical device. The signal terminal mounting position limits the signal terminal at an end away from the plug-in portion.

[0008] Preferably, one of the adjacent current-carrying sheet and the electrode sheet is provided with a current-drawing sheet protruding thereon, and the other is provided with a current-drawing opening, and the current-drawing sheet extends into the current-drawing opening and is connected by welding.

[0009] Preferably, a flat fuse is connected between the current-carrying sheet and the electrode sheet.

[0010] Preferably, the flat fuse includes a busbar portion arranged at both ends and a narrow bridge portion connecting the busbar portions, the two busbar portions are respectively connected to the current-carrying sheet and the electrode sheet, the width of the narrow bridge portion is smaller than the width of the busbar portion, and the narrow bridge portion is melted when the current flowing through the narrow bridge portion exceeds a preset value.

[0011] Preferably, a current-carrying sheet, a flat fuse and an electrode sheet are provided with a current-drawing sheet protruding from one of the adjacent two sheets, and a current-drawing port is provided on the other sheet, and the current-drawing sheet extends into the current-drawing port and is connected by welding.

[0012] Preferably, an upper pressing sheet portion is provided on one of two adjacent ones of the current-carrying sheet, the flat fuse and the electrode sheet, and a lower pressing sheet portion is provided on the other one, the upper pressing sheet portion is superimposed on the lower pressing sheet portion, and the two are connected by laser welding.

[0013] Preferably, a positioning groove is provided on the housing, the shape of the positioning groove is adapted to the shape of the flat-type fuse, and the flat-type fuse is placed in the positioning groove.

[0014] Preferably, a groove inclined toward the center of the power inlet is formed around the power inlet.

[0015] After adopting the above technical solution, the utility model has the following beneficial effects.

[0016] 1. A battery pack proposed by the utility model has a current-carrying sheet at the upper end of a circuit board, and a plug-in terminal is integrally formed on the current-carrying sheet, and the plug-in terminal is used to plug in an electrical device for inputting or outputting current. With such a configuration, when the battery pack is charged or discharged, a large current is input or output through the current-carrying sheet instead of the circuit board, thereby avoiding heating of the circuit board and making the working state of each component installed on the circuit board more normal; then, since the heat generation of the circuit board is reduced, the spacing between each component on the circuit board can be shortened, the circuit board can be designed to be more compact, and the size of the circuit board can be reduced, thereby reducing the material consumption and production cost of the circuit board; and First, the plug-in terminals are integrally formed on the current carrier, avoiding the need to connect the two for electrical conduction due to the separate settings of the two, thereby avoiding problems in the use of the battery pack due to poor connection between the two, and reducing the steps in the installation process, thereby reducing production costs; finally, the current carrier is set on the upper end of the circuit board and can directly contact the air. In this way, the current carrier is easier to dissipate heat. At the same time, the circuit board is isolated between the current carrier and the battery pack. The heat generated by the current passing through the current carrier is not easily transferred to the battery pack due to the isolation of the circuit board. The battery pack close to the circuit board is also not prone to high temperature, thereby better maintaining the working performance and service life of the battery pack.

[0017] 2. A mounting seat insulated from the circuit board is fixed at the upper end of the circuit board, and a carrier chip mounting position is provided on the mounting seat. The carrier chip is placed in the carrier chip mounting position, and the carrier chip mounting position limits the carrier chip on the side away from the plug-in terminal. This arrangement can prevent the carrier chip from being displaced due to excessive plugging during the plugging process of the battery pack, which causes force between the pins of the carrier chip and the circuit board and causes the two to become desoldered, thereby ensuring the reliability of the battery pack. At the same time, by providing a mounting seat insulated from the circuit board, direct contact between the carrier chip and the circuit board to cause cross-current is avoided, thereby better protecting the circuit board.

[0018] 3. Signal terminals are also installed on the circuit board. A signal terminal mounting position insulated from the carrier chip mounting position is provided on the mounting seat. The signal terminal is placed in the signal terminal mounting position. The signal terminal includes a plug-in portion for plugging in a signal connector of an electrical device. The signal terminal mounting position limits the signal terminal at the end away from the plug-in portion. This arrangement can prevent the signal terminal from shaking or shifting due to excessive plugging during the plugging process of the battery pack, which may cause force between the signal terminal and the circuit board and cause the two to become desoldered, thereby ensuring the reliability of the battery pack.

[0019] 4. A current-drawing sheet is convexly provided on one of the adjacent current-carrying sheet and the electrode sheet, and a current-drawing port is provided on the other one. The current-drawing sheet extends into the current-drawing port and is welded together. With this arrangement, the cooperation between the current-drawing port and the current-drawing sheet can play an auxiliary positioning function. There is no need to fix the two by hand when welding them, which reduces the difficulty of operation for the operator; secondly, the positive current-carrying sheet and the load current-carrying sheet are of different shapes and sizes. When the current-carrying sheet is installed incorrectly, the current-drawing sheets on the adjacent current-carrying sheet and electrode sheet cannot extend into the current-drawing port, thereby playing an error-prevention role.

[0020] 5. A flat-plate fuse is connected between the current-carrying sheet and the electrode sheet. By connecting the flat-plate fuse between the current-carrying sheet and the electrode sheet of the battery pack, it plays a supporting role to prevent the current output by the battery pack from exceeding its maximum discharge current, thereby avoiding the possible rapid degradation of the performance and life of the battery pack; secondly, the flat-plate fuse has a flat shape. Compared with traditional fuses, the flat-plate fuse occupies less space and is more suitable for being set in the battery pack, which is beneficial to the layout optimization of the components on the battery pack; thirdly, the flat-plate fuse has a larger surface area and better heat dissipation performance than traditional fuses, which helps to reduce the risk of premature melting due to overheating.

[0021] 6. The flat-plate fuse includes a busbar portion arranged at both ends and a narrow bridge portion connecting the busbar portions. The two busbar portions are respectively connected to the current-carrying sheet and the electrode sheet. The width of the narrow bridge portion is smaller than the width of the busbar portion. When the current flowing through the narrow bridge portion exceeds a preset value, the narrow bridge portion is melted. With this arrangement, the wider busbar portion can share the heat generated by the current flowing through, which helps to keep the flat-plate fuse at a lower operating temperature when the melting current is not reached, which is beneficial to the stable operation of the fuse itself and extends its service life; secondly, the narrow bridge portion can quickly heat up and melt when the current flowing through it exceeds a preset value, thereby achieving precise overcurrent protection.

[0022] 7. A lead-in sheet is protruding from one of the adjacent two of the current-carrying sheet, the busbar portion and the electrode sheet, and a lead-in port is provided on the other one. The lead-in sheet extends into the lead-in port and is welded together. With this arrangement, the flat fuse, the current-carrying sheet and the adjacent electrode sheet are assisted in positioning by the cooperation of the lead-in port and the lead-in sheet. The two welded sheets do not need to be fixed by hand during welding, which reduces the difficulty of operation for the operator.

[0023] 8. An upper pressing sheet portion is provided on one of two adjacent ones of the current carrier, the busbar portion and the electrode sheet, and a lower pressing sheet portion is provided on the other one. The upper pressing sheet portion is superimposed on the lower pressing sheet portion, and the two are connected by laser welding. By adopting laser welding to weld the current carrier and the electrode sheet, there is no need to use solder, thus saving material cost. At the same time, since there is no solder, the high heat generated by the large current will not cause the solder to melt and destroy the welded connection between the two.

[0024] 9. A positioning groove is provided at the upper end of the shell, and the shape of the positioning groove is adapted to the appearance of the flat-plate fuse. This arrangement is conducive to the positioning of the flat-plate fuse during installation, and improves the convenience of the operator when welding and fixing the flat-plate fuse; secondly, the flat-plate fuse is placed in the positioning groove. When the battery pack is removed from the power tool or charger, the groove wall of the positioning groove can play a certain protective role, reducing or avoiding the occurrence of damage to the flat-plate fuse due to collision.

[0025] 10. By forming a groove around the power lead-in port that is inclined toward the center of the power lead-in port, more welding material can be filled in the welding position, thereby increasing the welding area between the power lead-in plate and the power lead-in port, making the two connected by welding more firmly.

[0026] These features and advantages of the present invention will be disclosed in detail in the following specific implementation manners and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a battery pack in an embodiment of the present utility model;

[0028] Figure 2 This is an exploded view of a battery pack in an embodiment of the utility model;

[0029] Figure 3 This is an exploded view of the components installed on the circuit board in the embodiment of the utility model;

[0030] Figure 4 It is a schematic diagram of a current-carrying sheet, an electrode sheet and a flat fuse in an embodiment of the utility model;

[0031] Figure 5 It is a schematic diagram of another current-carrying sheet, an electrode sheet and a flat fuse in an embodiment of the utility model;

[0032] Figure 6 It is a schematic diagram of another current-carrying sheet, an electrode sheet and a flat fuse in an embodiment of the utility model;

[0033] Figure 7 It is a schematic diagram of a battery pack equipped with a flat-plate fuse in an embodiment of the present utility model;

[0034] Reference numerals:

[0035] 100, battery pack, 110, housing, 111, positioning groove, 120, battery, 130, electrode sheet, 131, positive electrode sheet, 132, negative electrode sheet;

[0036] 200, circuit board, 210, mounting seat, 211, carrier chip mounting position, 2111, positive carrier chip mounting position, 2112, load chip mounting position, 212, signal terminal mounting position, 2121, first signal terminal mounting position, 2122, second signal terminal mounting position, 220, signal terminal, 221, first signal terminal, 222, second signal terminal, 223, plug-in portion;

[0037] 300, current-carrying sheet, 301, positive current-carrying sheet, 302, load current-carrying sheet, 310, plug-in terminal, 320, current-leading sheet, 330, current-leading port, 331, groove, 340, upper pressing sheet portion, 350, lower pressing sheet portion;

[0038] 400, flat fuse, 410, busbar portion, 420, narrow bridge portion. DETAILED DESCRIPTION

[0039] The following is an explanation and description of the technical scheme of the embodiment of the utility model in conjunction with the drawings of the embodiment of the utility model, but the following embodiment is only a preferred embodiment of the utility model, not all. Based on the embodiment in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the utility model.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" and "several" mean two or more, unless otherwise clearly defined.

[0042] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] Embodiment 1:

[0044] like Figures 1 to 5 As shown, a battery pack 100 proposed in an embodiment of the utility model includes a housing 110, a plurality of batteries 120 installed in the housing 110, and a circuit board 200 installed on the housing 110. The circuit board 200 can be used to monitor at least one of the following working data of the battery pack 100: temperature, voltage, current, resistance, state of charge, etc., and the circuit board 200 sends a corresponding signal to an electrically connected charger or electric tool according to the above working data. Electrical components, sensors, control chips, etc. for realizing the above functions are installed or electrically connected on the circuit board 200.

[0045] The housing 110 is provided with a plurality of positioning pieces, and the circuit board 200 is correspondingly provided with a plurality of strip holes, and the positioning pieces extend into the strip holes so as to position the circuit board 200 on the housing 110. The housing 110 is also provided with a plurality of connecting posts, and the connecting posts are provided with screw holes, and the circuit board 200 is correspondingly provided with a plurality of mounting holes, and the threaded ends of the screws pass through the mounting holes and are screwed into the screw holes so as to fix the circuit board 200 on the housing 110.

[0046] The battery pack 100 body is provided with an electrode sheet 130 electrically connected to the battery. The electrode sheet 130 includes a positive electrode sheet 131 connected to the positive electrode of the battery and a negative electrode sheet 132 connected to the negative electrode of the battery.

[0047] The multiple batteries 120 in the battery pack 100 may be connected in series or in parallel, some of them may be connected in series and then in parallel, or some of them may be connected in parallel and then in series.

[0048] The battery pack 100 also includes a current-carrying sheet 300 installed on the upper end of the circuit board 200. The current-carrying sheet 300 includes a positive current-carrying sheet 301 connected to the positive electrode sheet 131 and a load current-carrying sheet 302 connected to the negative electrode sheet 132. A plug-in terminal 310 is integrally formed on the current-carrying sheet 300. The plug-in terminal 310 is used to plug in electrical devices that input or output current, such as power tools, chargers, etc.

[0049] With such arrangement, when the battery pack 100 is charged or discharged, a large current is input or output through the current carrier 300 instead of the circuit board 200, thereby avoiding heating of the circuit board 200 and making the working state of each component installed on the circuit board 200 more normal; then, since the heat generation of the circuit board 200 is reduced, the spacing between the components on the circuit board 200 can be shortened, the circuit board 200 can be designed to be more compact, and the size of the circuit board 200 can be reduced, thereby reducing the material usage and production cost of the circuit board 200; furthermore, the plug-in terminal 310 is integrally formed on the current carrier 300, avoiding the need to connect the two conductively and separately. , thereby avoiding problems in the use of the battery pack 100 due to poor connection between the two, and reducing the steps of the installation process, thereby reducing production costs; finally, the current carrier 300 is arranged on the upper end of the circuit board 200 and can directly contact the air. In this way, the current carrier 300 is easier to dissipate heat. At the same time, the circuit board 200 is isolated between the current carrier 300 and the battery pack 100. The heat generated by the current passing through the current carrier 300 is not easily transferred to the battery pack 100 due to the isolation of the circuit board 200. The battery pack 100 close to the side of the circuit board 200 is also not easy to heat up, thereby better maintaining the working performance and service life of the battery pack 100.

[0050] The current carrier sheet 300 is formed by stamping and bending processes. The current carrier sheet 300 needs to have good conductivity and low resistance, preferably copper, and can also be other metals, such as aluminum, silver, etc.

[0051] The carrier sheet 300 is provided with a plurality of pins, and the carrier sheet 300 is positioned on the circuit board 200 through the pins. The pins are welded to the circuit board 200 to electrically connect the two, thereby providing the power required by the circuit board 200. The carrier sheet 300 is provided with through holes, and the threaded ends of the screws fixing the circuit board 200 also pass through the through holes of the carrier sheet 300, so that the carrier sheet 300 and the circuit board 200 are fixed together on the housing 110, thereby improving the installation reliability between the carrier sheet 300 and the circuit board 200.

[0052] In this embodiment, if Figures 1 to 5 As shown, a mounting base 210 insulated from the circuit board 200 is fixed at the upper end of the circuit board 200, and a carrier chip mounting position 211 is provided on the mounting base 210. The carrier chip 300 is placed in the carrier chip mounting position 211, and the carrier chip mounting position 211 limits the carrier chip 300 on the side away from the plug-in terminal 310.

[0053] Specifically, the current carrier chip installation position 211 includes a positive current carrier chip installation position 2111 and a load current carrier chip installation position 2112 which are insulated from each other. The positive current carrier chip 301 is placed in the positive current carrier chip installation position 2111, and the load current carrier chip 302 is placed in the load current carrier chip installation position 2112. A limiting back plate is provided on the side of the current carrier chip installation position 211 away from the plug-in terminal 310. When the battery pack 100 is plugged into an electric tool or a charger, the limiting back plate stops at the end of the current carrier chip 300 away from the plug-in terminal 310 to limit the It is restrained from moving in a direction away from the plug-in terminal 310, thereby preventing the current carrier 300 from being displaced due to excessive plugging during the plugging process of the battery pack 100, causing force between the pins 320 of the current carrier 300 and the circuit board 200 and causing the two to become desoldered, thereby ensuring the reliability of the battery pack 100; at the same time, by providing a mounting base 210 insulated from the circuit board 200, direct contact between the current carrier 300 and the circuit board 200 to cause cross-current is avoided, thereby better protecting the circuit board 200.

[0054] In some other embodiments, a mounting hole may be provided on the current carrier 300, and a screw hole may be provided on the current carrier mounting position 211, and the current carrier 300 may be fixed to the current carrier mounting position 211 by screws, so that the current carrier mounting position 211 restricts the movement of the current carrier 300.

[0055] The mounting base 210 is fixedly mounted on the circuit board 200 by screws. In some other embodiments, the mounting base 210 can also be fixed on the circuit board 200 by buckle clamping.

[0056] This embodiment is preferred, such as Figures 1 to 5 As shown, a signal terminal 220 is also mounted on the circuit board 200, and a signal terminal mounting position 212 insulated from the carrier chip mounting position 211 is provided on the mounting seat 210, and the signal terminal 220 is placed in the signal terminal mounting position 212, and the signal terminal 220 includes a plug-in portion 223 for plugging in a signal connector of an electrical device, and the signal terminal mounting position 212 limits the signal terminal 220 on a side away from the plug-in portion 223. The signal terminal 220 is connected to the circuit board 200 by welding, and a hole is provided at the bottom of the signal terminal mounting position 212 for one end of the signal terminal 220 to pass through, and the signal terminal 220 and the circuit board 200 are preferably welded by wave soldering.

[0057] Specifically, the signal terminal 220 includes a first signal terminal 221 and a second signal terminal 222, and the signal terminal mounting position 212 includes a first signal terminal mounting position 2121 and a first signal terminal mounting position 2122 that are insulated from each other, the first signal terminal 221 is placed in the first signal terminal mounting position 2121, and the second signal terminal 222 is placed in the first signal terminal mounting position 2122, and a limiting back plate is provided on the side of the signal terminal mounting position 212 away from the plug-in portion 223. When the battery pack 100 is plugged into an electric tool or a charger, the limiting back plate stops the signal terminal 220 from moving in a direction away from the plug-in portion 223, thereby preventing the battery pack 100 from shaking or displacing the signal terminal 220 due to excessive plugging during the plug-in process, causing force between the signal terminal 220 and the circuit board 200, resulting in desoldering of the two, thereby ensuring the reliability of the battery pack 100.

[0058] In some other embodiments, the signal terminal mounting position 212 and the signal terminal 220 may be fixedly connected to achieve the function that the signal terminal mounting position 212 restricts the movement of the signal terminal 220, for example, by screw connection.

[0059] In this embodiment, the current-carrying sheet 300 is connected to the electrode sheet 130 by welding to ensure the connection reliability and good conductivity between the two.

[0060] In a preferred embodiment, Figure 4 As shown, the positive current-carrying sheet 301 is provided with a lead-in port 330, and the positive electrode sheet 131 is provided with a lead-in plate 320, which is inserted into the lead-in port 330 and connected by welding. In this way, the cooperation between the lead-in port 330 and the lead-in plate 320 can play an auxiliary positioning function, and there is no need to fix the two by hand when welding, which reduces the difficulty of operation for the operator; secondly, the positive current-carrying sheet 301 and the load current-carrying sheet 302 are of different shapes and sizes. When the current-carrying sheet 300 is installed incorrectly, the lead-in plates 320 on the adjacent current-carrying sheets 300 and the electrode sheet 130 cannot be inserted into the lead-in port 330, thereby playing an error-proofing role.

[0061] It is understandable that the positive electrode sheet 131 is provided with a current lead-in port 330 , and the positive current-carrying sheet 301 is provided with a current lead-in sheet 320 convexly.

[0062] In some other embodiments, the load flow sheet 302 may be provided with a lead-in port 330 , and the negative electrode sheet 132 may be provided with a lead-in plate 320 ; or the negative electrode sheet 132 may be provided with a lead-in port 330 , and the load flow sheet 302 may be provided with a lead-in plate 320 .

[0063] In this embodiment, a groove 331 inclined toward the center of the current lead-in port 330 is formed around the current lead-in port 330. In this way, the groove 331 can allow more welding material to be filled in the welding position, thereby increasing the welding area between the current lead-in sheet 320 and the current lead-in port 330, making the welding between the current carrier sheet 300 and the electrode sheet 130 more secure.

[0064] In another preferred embodiment, Figure 5 As shown, an upper pressing sheet 340 is provided on the positive current-carrying sheet 301, and a lower pressing sheet 350 is provided on the positive electrode sheet 131. The upper pressing sheet 340 is superimposed on the lower pressing sheet 350, and the upper pressing sheet 340 and the lower pressing sheet 350 are connected by laser welding. By using laser welding to weld the current-carrying sheet 300 and the electrode sheet 130, solder does not need to be used, saving material costs; at the same time, since there is no solder, the high heat generated by the large current will not cause the solder to melt and destroy the state of the two being welded together.

[0065] In some other embodiments, the positive current carrier sheet 301 may be provided with a lower pressing sheet portion 350, and the positive electrode sheet 131 may be provided with an upper pressing sheet portion 340. When installing, the circuit board 200 is first placed obliquely, the lower pressing sheet portion 350 on the positive current carrier sheet 301 is inserted under the upper pressing sheet portion 340, and then the circuit board 200 is placed flat and installed on the housing 110.

[0066] Embodiment 2:

[0067] Based on Example 1, Figure 4 , Figure 6 As shown, in this embodiment, a planar fuse 400 is connected between the load flow sheet 302 and the negative electrode sheet 132 . Usually, a fuse is already provided on the power tool connected to the battery pack 100, and the fuse blows when the current is too large. However, if the fuse on the power tool fails and the current is too large during operation, or the fuse breaking current of the power tool is greater than the maximum discharge current of the battery pack 100, the battery pack 100 may have various problems such as excessive temperature rise, increased internal pressure, capacity decay and performance degradation. Therefore, a flat fuse 400 is connected between the load flow sheet 302 and the negative electrode sheet 132 of the battery pack 100 to play a bottoming role, thereby preventing the current output by the battery pack 100 from exceeding its maximum discharge current, thereby avoiding possible rapid decay of the performance and life of the battery pack 100. Secondly, the flat fuse 400 has a flat shape. Compared with traditional fuses, the flat fuse 400 occupies less space and is more suitable for being set in the battery pack 100, which is conducive to the layout optimization of the components on the battery pack 100. Furthermore, the flat fuse 400 has a larger surface area and better heat dissipation performance than traditional fuses, which helps to reduce the risk of premature melting due to overheating.

[0068] In some other embodiments, the planar fuse 400 may also be disposed between the positive current carrying sheet 301 and the positive electrode sheet 131 .

[0069] In this embodiment, if Figure 4 , Figure 6 As shown, the flat fuse 400 includes busbars 410 disposed at both ends and narrow bridges 420 connecting the busbars 410 at both ends. The two busbars 410 are connected to the current-carrying sheet 300 and the electrode sheet 130 respectively. The width of the narrow bridge 420 is smaller than the width of the busbars 410. When the current flowing through the narrow bridge 420 exceeds a preset value, the narrow bridge 420 is blown. With such a configuration, the wider busbars 410 can share the heat generated by the current flowing through, which helps to keep the flat fuse 400 at a lower operating temperature when the blown current is not reached, which is beneficial to the stable operation of the flat fuse 400 itself and prolongs its service life; secondly, the narrow bridge 420 can quickly heat up and blow when the current flowing through it exceeds a preset value, thereby achieving precise overcurrent protection.

[0070] In this embodiment, the planar fuse 400 is connected to the current-carrying sheet 300 and the electrode sheet 130 by welding, respectively, so as to ensure the connection reliability and good conductivity of the planar fuse 400 and the current-carrying sheet 300 and the electrode sheet 130 .

[0071] In a preferred embodiment, Figure 4 As shown, the busbars 410 at both ends of the flat fuse 400 are formed with lead-in ports 330 , and the load busbars 302 and the negative electrode sheet 132 are respectively provided with lead-in plates 320 , which extend into the lead-in ports 330 and are welded together.

[0072] In some other embodiments, the load current sheet 302 and the negative electrode sheet 132 may be provided with a lead-in port 330, respectively, and the busbars 410 at both ends of the flat fuse 400 may be provided with a lead-in plate 320. It is understandable that the lead-in plate 320 and the lead-in port 330 may be provided on the two busbars 410, respectively, and the load current sheet 302 and the negative electrode sheet 132 may also be provided with a lead-in plate 320 and a lead-in port 330, respectively. In some other embodiments, the flat fuse 400, the positive current sheet 301, and the positive electrode sheet 131 may be pre-positioned and connected by welding through the lead-in port 330 and the protruding lead-in plate 320.

[0073] With such arrangement, the flat fuse 400, the current-carrying sheet 300 and the electrode sheet 130 can play an auxiliary positioning function through the cooperation of the current-intake port 330 and the current-intake sheet 320. The two welded together do not need to be fixed by hand during welding, which reduces the difficulty of operation for the operator.

[0074] In this embodiment, a groove 331 inclined toward the center of the current lead-in port 330 is formed around the current lead-in port 330. In this way, the groove 331 can allow more welding material to be filled in the welding position, thereby increasing the welding area between the current lead-in sheet 320 and the current lead-in port 330, making the welding between the current carrier sheet 300 and the electrode sheet 130 more secure.

[0075] In another preferred embodiment, Figure 6 As shown, the busbars 410 at both ends of the flat fuse 400 form an upper pressing plate 340, the load plate 302 and the negative electrode plate 132 are provided with a lower pressing plate 350, the upper pressing plate 340 is superimposed on the lower pressing plate 350, and the upper pressing plate 340 and the lower pressing plate 350 are connected by laser welding. By using laser welding to weld the current-carrying plate 300 and the electrode plate 130, solder does not need to be used, saving material costs; at the same time, because there is no solder, the high heat generated by the large current will not cause the solder to melt and destroy the state of the two being welded together.

[0076] In some other embodiments, the busbars 410 at both ends of the flat fuse 400 may form a lower pressing plate 350, and the load plate 302 and the negative electrode plate 132 may be provided with an upper pressing plate 340. It is understandable that the busbars 410 at both ends of the flat fuse 400 may also form an upper pressing plate 340 and a lower pressing plate 350, respectively, and the load plate 302 and the negative electrode plate 132 may be provided with a lower pressing plate 350 and an upper pressing plate 340, respectively.

[0077] During laser welding, two adjacent ones of the planar fuse 400 , the current carrier sheet 300 , and the electrode sheet 130 may be clamped and fixed by a fixture before being welded.

[0078] For other contents not described in this embodiment, please refer to Embodiment 1.

[0079] Embodiment three:

[0080] Based on the second embodiment, in this embodiment, combined with Figure 1 , Figure 7 , a positioning groove 111 is further provided at the upper end of the housing 110, and the shape of the positioning groove 111 is adapted to the shape of the flat-plate fuse 400, and the flat-plate fuse 400 is placed in the positioning groove 111. Such a configuration is conducive to the positioning of the flat-plate fuse 400 when it is installed, and improves the convenience of the operator when welding and fixing the flat-plate fuse 400; secondly, the flat-plate fuse 400 is placed in the positioning groove 111, and when the battery pack 100 is removed from the power tool or charger, the groove wall of the positioning groove 111 can play a certain protective role, reducing or avoiding the occurrence of damage to the flat-plate fuse 400 due to collision.

[0081] For other contents not described in this embodiment, reference may be made to the aforementioned embodiments.

[0082] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Those skilled in the art should understand that the utility model includes but is not limited to the contents described in the drawings and the above specific implementation. Any modification that does not deviate from the functional and structural principles of the utility model will be included in the scope of the claims.

Claims

1. A battery pack, comprising a housing (110), a plurality of batteries (120) mounted in the housing (110), and a circuit board (200) mounted on the housing (110), wherein the housing (110) is provided with an electrode sheet (130) electrically connected to the battery (120), the electrode sheet (130) comprising a positive electrode sheet (131) and a negative electrode sheet (132), characterized in that: It also includes a current-carrying sheet (300) installed on the upper end of the circuit board (200), the current-carrying sheet (300) including a positive current-carrying sheet (301) connected to the positive electrode sheet (131) and a negative current-carrying sheet (302) connected to the negative electrode sheet (132), and a plug-in terminal (310) is integrally formed on the current-carrying sheet (300), and the plug-in terminal (310) is used to plug in an electrical device that inputs or outputs current.

2. A battery pack as claimed in claim 1, characterized in that: A mounting seat (210) insulated from the circuit board (200) is fixed at the upper end of the circuit board (200); a carrier chip mounting position (211) is provided on the mounting seat (210); the carrier chip (300) is placed in the carrier chip mounting position (211); the carrier chip mounting position (211) limits the carrier chip (300) on a side away from the plug-in terminal (310).

3. A battery pack as claimed in claim 2, characterized in that: A signal terminal (220) is also mounted on the circuit board (200); a signal terminal mounting position (212) insulated from the carrier chip mounting position (211) is provided on the mounting seat (210); the signal terminal (220) is placed in the signal terminal mounting position (212); the signal terminal (220) comprises a plug-in portion (223) for plugging into a signal connector of an electrical device; the signal terminal mounting position (212) limits the signal terminal (220) at an end away from the plug-in portion (223).

4. A battery pack as claimed in claim 1, characterized in that: One of the adjacent current-carrying sheet (300) and the electrode sheet (130) is provided with a lead-in sheet (320) protruding thereon, and the other is provided with a lead-in opening (330), wherein the lead-in sheet (320) extends into the lead-in opening (330) and is connected by welding.

5. A battery pack as claimed in claim 1, characterized in that: A flat fuse (400) is connected between the current-carrying sheet (300) and the electrode sheet (130).

6. A battery pack as claimed in claim 5, characterized in that: The flat fuse (400) comprises busbar portions (410) arranged at both ends and narrow bridge portions (420) connecting the busbar portions (410); the two busbar portions (410) are respectively connected to the current-carrying sheet (300) and the electrode sheet (130); the width of the narrow bridge portion (420) is smaller than the width of the busbar portion (410); and the narrow bridge portion (420) is melted when the current flowing through the narrow bridge portion (420) exceeds a preset value.

7. A battery pack as claimed in claim 5, characterized in that: One of the adjacent two of the current-carrying sheet (300), the flat fuse (400) and the electrode sheet (130) is provided with a lead-in sheet (320) protruding thereon, and the other is provided with a lead-in opening (330), and the lead-in sheet (320) extends into the lead-in opening (330) and is connected by welding.

8. A battery pack as claimed in claim 5, characterized in that: An upper pressing sheet portion (340) is provided on one of two adjacent ones of the current-carrying sheet (300), the flat fuse (400) and the electrode sheet (130), and a lower pressing sheet portion (350) is provided on the other one; the upper pressing sheet portion (340) is superimposed on the lower pressing sheet portion (350), and the two are connected by laser welding.

9. A battery pack according to any one of claims 5 to 8, characterized in that: The housing (110) is provided with a positioning groove (111), the shape of the positioning groove (111) is adapted to the appearance of the flat-plate fuse (400), and the flat-plate fuse (400) is placed in the positioning groove (111).

10. A battery pack according to claim 4 or 7, characterized in that: A groove (331) inclined toward the center of the power introduction port (330) is formed around the power introduction port (330).

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