Battery pack

Abstract

The utility model relates to a battery pack. The battery pack comprises a shell, a plurality of battery cells mounted in the shell, a circuit board electrically connected with the battery cells and an output terminal connected to the circuit board, the battery core, the circuit board and the output terminal form a current path, and electric energy is input / output through the output terminal. The battery pack also includes a first conductive member, a second conductive member, and a fuse element in the current path. The safety element is electrically connected between the first conductive piece and the second conductive piece, and a gap exists between the safety element and the circuit board. According to the battery pack provided by the invention, adverse effects caused by heat accumulation in the battery pack can be reduced, so that normal use of the battery pack is ensured.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of circuit protection structure, in particular to a battery pack. BACKGROUND

[0002] With the continuous enrichment of the types of electric tools, more and more electric tools begin to be equipped with battery packs for power supply. By equipping independent battery packs in electric tools, it is convenient for workers to use electric tools for operation, especially in some difficult power supply operation occasions, which can provide great convenience for the operation process.

[0003] In order to ensure the safety performance of the battery pack, a fuse element is introduced in the circuit design of the circuit board. The fuse element can be fused when an abnormal situation occurs, so as to cut off the current loop in the battery pack. However, the fuse element in the existing battery pack adopts a patch form. When a large current load occurs, a high heat accumulation phenomenon occurs, which causes the fuse to be displaced or detached due to the melting of the patch solder, resulting in damage to the battery pack. Therefore, how to reduce the adverse effects caused by heat accumulation in the battery pack to ensure the normal use of the battery pack is an important problem. CONTENT OF THE INVENTION

[0004] The purpose of the embodiment of the present application is to provide a battery pack which can reduce the adverse effects caused by heat accumulation in the battery pack to ensure the normal use of the battery pack.

[0005] To solve the above technical problems, the embodiment of the present application provides a battery pack. The battery pack comprises a shell, a plurality of battery cells mounted on the shell, a circuit board electrically connected to the battery cells, and an output terminal connected to the circuit board. The battery cells, the circuit board and the output terminal constitute a current path, and input / output electric energy through the output terminal. The battery pack further comprises a first conductive member, a second conductive member and a fuse element located in the current path. The fuse element is electrically connected between the first conductive member and the second conductive member, and there is a gap between the fuse element and the circuit board.

[0006] The battery pack provided by the embodiment of the present application achieves the circuit protection effect through the fuse element in the current path of the output terminal of the circuit board connected to the battery cells. The first conductive member and the second conductive member are placed at the fixed position of the fuse element, and the first conductive member and the second conductive member form a fixed structure of the fuse element. The connection basis formed by different conductive members is used to install the fuse element on the circuit board, which is beneficial to the dissipation of heat and reduces the mutual conduction of heat between the fuse element and the circuit board, so as to reduce the adverse effects caused by heat accumulation in the battery pack to ensure the normal use of the battery pack.

[0007] In some embodiments, the battery pack further comprises a positive connection sheet electrically connected to the positive pole of the battery cell, a negative connection sheet electrically connected to the negative pole of the battery cell, the output terminal comprises a first terminal and a second terminal, the first terminal is connected to the positive connection sheet, and the first conductive piece, the second conductive piece and the protection element are located between the negative connection sheet and the second terminal. In this way, the protection element can be arranged between the negative connection sheet and the second terminal to play a circuit protection role at a position close to the negative pole.

[0008] In some embodiments, one end of the first conductive piece is connected to the negative connection sheet, the other end is connected to the protection element, and the first conductive piece is provided with a first stepped surface and a first positioning surface connected to the first stepped surface, one end of the protection element is provided with a first conductive part located on the first stepped surface and abutting on the first positioning surface. In this way, the first end of the protection element can be clamped and limited by the cooperation between the first stepped surface and the first positioning surface on the first conductive piece.

[0009] In some embodiments, one end of the second conductive piece is connected to the second terminal, the other end is connected to the protection element, and the second conductive piece is provided with a second stepped surface and a second positioning surface connected to the second stepped surface, the other end of the protection element is provided with a second conductive part located on the second stepped surface and abutting on the second positioning surface. In this way, the other end of the protection element can be clamped and limited by the cooperation between the second stepped surface and the second positioning surface on the second conductive piece.

[0010] In some embodiments, the distance between the edge of the first positioning surface away from the first stepped surface and the first stepped surface is 1-2 mm, and the distance between the edge of the second positioning surface away from the second stepped surface and the second stepped surface is 1-2 mm. In this way, by controlling the height of the positioning surface on the stepped surface, the installation and fixing effect between the protection element and the conductive piece can be ensured.

[0011] In some embodiments, the first conductive piece is provided with two opposite first limiting parts, the two first limiting parts are arranged on the first stepped surface and abut on both sides of the protection element, and the second conductive piece is provided with two opposite second limiting parts, the two second limiting parts are arranged on the second stepped surface and abut on both sides of the protection element. In this way, the position of both sides of the protection element can be limited by the limiting parts on the conductive piece.

[0012] In some embodiments, the first conductive piece is provided with a plurality of first pins, and the plurality of first pins pass through the circuit board from one side of the circuit board to the other side of the circuit board. In this way, by arranging a plurality of first pins, the first conductive piece can be easily installed on the circuit board.

[0013] In some embodiments, the second conductive member is provided with a plurality of second pins, the plurality of second pins passing through the circuit board from one side of the circuit board to the other side of the circuit board. In this way, the second conductive member can be conveniently mounted on the circuit board by providing the plurality of second pins.

[0014] In some embodiments, the plurality of fuse elements are arranged in parallel between the first conductive member and the second conductive member. In this way, the overcurrent capacity can be improved by increasing the number of fuse elements, so as to adapt to the safe use of the battery pack under large-current discharge.

[0015] In some embodiments, the first conductive member and the second conductive member are arranged adjacent to the same end of the circuit board. In this way, the fixing positions of the components on the circuit board can be controlled, so as to effectively utilize the layout space on the circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0016] One or more embodiments are illustrated by way of example in the figures that form a part of this disclosure and which do not limit the scope of the embodiments, in which like references indicate similar elements. The drawings in the figures are not necessarily to scale, the emphasis instead being placed upon illustrating the principles of the embodiments.

[0017] Figure 1 is a schematic diagram of an explosion structure of a battery pack provided by some embodiments of the present application;

[0018] Figure 2 is a schematic diagram of the cooperation structure of a circuit board and a battery cell in a battery pack provided by some embodiments of the present application;

[0019] Figure 3 is a schematic diagram of the cross-sectional structure of a battery cell in a battery pack provided by some embodiments of the present application;

[0020] Figure 4 is a schematic diagram of the front view structure of a circuit board in a battery pack provided by some embodiments of the present application, the circuit board being provided with a fuse element;

[0021] Figure 5 is a schematic diagram of the top view structure of a circuit board in a battery pack provided by some embodiments of the present application, the circuit board being provided with a fuse element;

[0022] Figure 6 is a schematic diagram of the assembly of a circuit board and a fuse element in a battery pack provided by some embodiments of the present application;

[0023] Figure 7 is a schematic diagram of the arrangement structure of a first conductive member and a second conductive member in a battery pack provided by some embodiments of the present application;

[0024] Figure 8 is a schematic diagram of the internal structure of a battery pack provided by some embodiments of the present application;

[0025] Figure 9 is a schematic view of the internal structure of the battery pack from another perspective, provided by some embodiments of the present application. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. However, it should be understood by those skilled in the art that, in the embodiments of the present application, many technical details are presented in order to make the reader better understand the present application. However, the technical solutions claimed by the present application can be implemented even without these technical details and based on various changes and modifications of the following embodiments. The division of the following embodiments is for the convenience of description, and should not constitute any limitation on the specific embodiments of the present application. The embodiments can be combined and referenced with each other without contradiction.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments of the present application and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0028] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection" and the like should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0029] As Figures 1 to 9As shown, the battery pack provided by some embodiments of the present application includes a housing 11, a plurality of battery cells 12 mounted on the housing 11, a circuit board 13 electrically connected to the battery cells 12, and output terminals connected to the circuit board 13. The housing 11 forms an encapsulation shell of the battery pack, and is used to provide a mounting base for other components and to protect other components. The housing 11 can adopt a split structure that is convenient to disassemble and assemble, for example, a form of cooperation of a bottom shell 101 and a top cover 102, and the bottom shell 101 and the top cover 102 can be connected by fasteners. The bottom shell 101 can form a mounting space, and the top cover 102 can be covered on an opening of the bottom shell 101. Meanwhile, the housing 11 is provided with a plug-in interface facing an interface seat 103 of the power tool, which is used to expose the output terminals so as to cooperate with a charging interface of a charger or to be assembled on a main body of the power tool to access a circuit of the power tool. The housing 11 can also be provided with a button 104, so that the battery pack is detachably connected to the charger or the power tool.

[0030] In the present embodiment, the battery cells 12, the circuit board 13, and the output terminals constitute a current path and supply the charger with electrical energy or output electrical energy to the power tool via the output terminals. The battery cells 12 are arranged in the housing 11, and the battery cells 12 are parts of the battery pack that realize electrical energy storage and output utilization. The battery cells 12 can be battery monomers that can be charged and discharged multiple times, and the battery monomers can adopt different types. The battery monomers are connected in series or in parallel. The battery cells 12 can be fixed by a mounting rack, and can be fixed at a mounting position of the housing 11 by the mounting rack.

[0031] The battery cells 12 have positive electrodes and negative electrodes, and form positive electrode interfaces and negative electrode interfaces that access external circuits, respectively. The plurality of battery cells 12 are connected in series and in parallel by connection pieces, and the connection pieces have positive connection pieces 121, negative connection pieces 122, and intermediate connection pieces 123. The connection pieces have an electrical connection function, and the battery cells 12 are electrically connected by the intermediate connection pieces 123. Meanwhile, the positive connection pieces 121 and the negative connection pieces 122 can be connected to the output terminals to output electrical energy stored by the plurality of battery cells 12 or to receive electrical energy input from the outside. The connection pieces are welded to the positive electrodes and the negative electrodes of the battery cells 12. It should be noted that the connection pieces are made of non-magnetic materials, and can be made of copper plated with nickel; in addition, at least three connection pieces are mounted on each side of the plurality of battery cells 12, and in the present embodiment, the number of the connection pieces on each side of the plurality of battery cells 12 is three.

[0032] The circuit board 13 is arranged in the housing 11, and the circuit board 13 is part of establishing a circuit loop in the battery pack, and the circuit board 13 can control the charging and discharging process of the battery cell 12 and protect the charging and discharging process of the battery cell 12. The circuit board 13 is formed with a circuit and can be electrically connected with the battery cell 12. The output terminal includes a first terminal 131 directly electrically connected with the positive connection sheet 121 and a second terminal 132 indirectly electrically connected with the negative connection sheet 122, which can be plugged with other terminals outside to realize the conduction of the battery cell 12 with the charging circuit of the charger or the power consumption circuit of the power tool. As shown in Figure 8 and Figure 9 The first terminal 131 and the second terminal 132 are directly / indirectly electrically connected with the positive connection sheet 121 and the negative connection sheet 122, respectively. The first terminal 131 and the second terminal 132 can be arranged adjacent to the same end of the circuit board 13.

[0033] The battery pack further includes a first conductive piece 14, a second conductive piece 15 and a fuse element 16 located in the current path, specifically, the first conductive piece 14, the second conductive piece 15 and the fuse element 16 are located between the negative connection sheet 122 and the second terminal 132. The fuse element 16 is electrically connected between the first conductive piece 14 and the second conductive piece 15, the fuse element 16 connects the first conductive piece 14 and the second conductive piece 15, and there is a gap between the fuse element 16 and the circuit board 13 to prevent the heat of the fuse element 16 from being dispersed by the circuit board, while avoiding affecting the electronic components on the circuit board. The first conductive piece 14 and the second conductive piece 15 are arranged in a spaced manner and form a clamping area 105. The fuse element 16 is arranged in the clamping area 105 and electrically connects the first conductive piece 14 and the second conductive piece 15. The first conductive piece 14 and the second conductive piece 15 are arranged on the circuit board 13 and can be used for fixing the fuse element 16. The first conductive piece 14 and the second conductive piece 15 both have a conductive effect, one end of the first conductive piece 14 is connected to the negative connection sheet 122, and the other end is connected to the fuse element 16. One end of the second conductive piece 15 is connected to the second terminal 132, and the other end is connected to the fuse element 16. A gap is formed between the first conductive piece 14 and the second conductive piece 15, which can provide a mounting area for the fixation of the fuse element 16 and cooperate with the base. The first conductive piece 14 and the second conductive piece 15 can be arranged adjacent to the same end of the circuit board 13 to effectively utilize the arrangement space on the circuit board 13.

[0034] The fuse element 16 is a part of the battery pack circuit that plays a protective role. The fuse body of the fuse element 16 can be fused when an abnormal situation such as current exceeding a threshold value occurs, thereby protecting the components in the circuit from adverse effects. The fuse element 16 adopts a fuse / fusor, and is spaced apart from the circuit board 13 to avoid direct contact with the circuit board 13, prevent heat from being directly transmitted to the circuit board 13, and avoid adverse effects on electronic components on the circuit board 13. The fuse element 16 has conductive connection parts on opposite sides, and after the fuse element 16 is fixed, the fuse element 16 can form an electrical connection between the first conductive part 14 and the second conductive part 15. In actual situations, there can be multiple fuse elements 16, and multiple fuse elements 16 are arranged in parallel between the first conductive part 14 and the second conductive part 15. As shown in FIGS. Figure 5 and Figure 6 Two fuse elements 16 are arranged side by side in the clamping area 105 formed between the first conductive part 14 and the second conductive part 15. Two fuse elements 16 can improve the overcurrent capacity of the current to adapt to the use environment of the battery pack under large current.

[0035] The battery pack provided in the present application achieves a circuit protection effect through the fuse element 16 in the current path between the output terminal of the circuit board 13 and the negative electrode connecting piece 122 connected to the battery cell 12. At the fixed position of the fuse element 16, the first conductive part 14 and the second conductive part 15 are placed, and the first conductive part 14 and the second conductive part 15 form a fixed structure of the fuse element 16. At the same time, one end of the first conductive part 14 is connected to the negative electrode connecting piece 122, and the other end is connected to the fuse element 16, one end of the second conductive part 15 is connected to the second terminal 132, and the other end is connected to the fuse element 16, thereby forming a complete current loop. The connection basis formed by different conductive parts spacers the fuse element 16 on the circuit board 13, which is conducive to heat dissipation and reduces the mutual conduction of heat between the fuse element 16 and the circuit board 13, and can reduce the adverse effects caused by heat accumulation in the battery pack to ensure the normal use of the battery pack.

[0036] In the embodiment, the first conductive member 14 has a first supporting surface, a first step surface 141 at one end of the first supporting surface, and a first positioning surface 142 connected to the first step surface 141. The fuse element 16 has a first conductive part 161 at one end, which is located on the first step surface 141 and abuts against the first positioning surface 142. The first step surface 141 and the first positioning surface 142 form a clamping structure on the first conductive member 14, and the first step surface 141 can be used to place the fuse element 16. The surface connected to the first step surface 141 can limit the position of the fuse element 16, so as to control the position of the end of the fuse element 16 and the first conductive member 14, i.e. the fixed position of the fuse element 16 on the first conductive member 14.

[0037] In addition, the second conductive member 15 has a second supporting surface, a second step surface 151 at one end of the second supporting surface, and a second positioning surface 152 connected to the second step surface 151. The fuse element 16 has a second conductive part 162 at the other end, which is located on the second step surface 151 and abuts against the second positioning surface 152. The second step surface 151 and the second positioning surface 152 form a clamping structure on the second conductive member 15, and the second step surface 151 can be used to place the fuse element 16. The surface connected to the second step surface 151 can limit the position of the fuse element 16, so as to control the position of the end of the fuse element 16 and the first conductive member 14, i.e. the fixed position of the fuse element 16 on the first conductive member 14.

[0038] In actual cases, the positioning surface and the step surface can be connected perpendicularly, so that the end of the fuse element 16 is limited in the clamping area 101 formed by the first conductive member 14 and the second conductive member 15. The two ends of the fuse element 16 are the parts for electrically connecting with the outside. When the fuse element 16 is placed in the clamping area 101, the two conductive parts of the fuse element 16 are located on the step surfaces of different conductive members, and the end surface of the fuse element 16 faces the positioning surface connected to the step surface. Thus, the fixed position of the fuse element 16 is positioned. In order to strengthen the connection effect, the end of the fuse element 16 can be partially welded and inversely welded. The welding material can fill the contact position of the conductive end and the conductive member, so as to tightly connect the fuse element 16 and the different conductive members together.

[0039] In this embodiment, the distance between the edge of the first positioning surface 142 away from the first step surface 141 and the first step surface 141 can be 1-2 mm, and the distance between the edge of the second positioning surface 152 away from the second step surface 151 and the second step surface 151 can be 1-2 mm. That is, a placement space with a depth of 1-2 mm corresponding to the fuse element 16 is designed on different conductive members, and the fuse element 16 can be fixed. The conductive member can adopt a sheet structure, and the fuse element 16 can be placed in the corresponding position to form a component with the sheet-shaped conductive member. The conductive member is inserted into the corresponding mounting hole of the circuit board 13 for welding. Thus, the fuse element 16 and different conductive members are fixed together with the circuit board 13 to form a circuit board assembly. In actual cases, the distance between the edge of the first positioning surface 142 away from the first step surface 141 and the first step surface 141 can be 1 mm, 1.5 mm, or 2 mm, and the distance between the edge of the second positioning surface 152 away from the second step surface 151 and the second step surface 151 can be 1 mm, 1.5 mm, or 2 mm.

[0040] As shown in Figure 7 The first conductive member 14 can be provided with two opposite first limiting portions 143, which are arranged on the first step surface 141 and abut against both sides of the fuse element 16. The first conductive member 14 is provided with two first limiting portions 143 on the first step surface 141, and when the fuse element 16 is placed such that part of the fuse element 16 is located on the first step surface 141, the two first limiting portions 143 are distributed on both sides of the fuse element 16. Thus, the two first limiting portions 143 limit the position of the fuse element 16 on both sides, ensuring that the fuse element 16 is always between the two first limiting portions 143 in the direction of the two sides.

[0041] In addition, the second conductive member 15 can be provided with two opposite second limiting portions 153, which are arranged on the second step surface 151 and abut against both sides of the fuse element 16. The second conductive member 15 is provided with two second limiting portions 153 on the second step surface 151, and when the fuse element 16 is placed such that part of the fuse element 16 is located on the second step surface 151, the two second limiting portions 153 are distributed on both sides of the fuse element 16. Thus, the two second limiting portions 153 limit the position of the fuse element 16 on both sides, ensuring that the fuse element 16 is always between the two second limiting portions 153 in the direction of the two sides.

[0042] In the embodiment, the first conductive member 14 can be provided with a plurality of first pins 144, which are substantially perpendicular to the first supporting surface, and the plurality of first pins 144 pass through the circuit board 13 from one side of the circuit board 13 to the other side of the circuit board 13. The first conductive member 14 as a whole can be provided in an irregular shape, and at the edge of the first conductive member 14, the plurality of first pins 144 can be formed in a bending form. The circuit board 13 is provided with first through holes corresponding to the first pins 144, and when the first conductive member 14 is placed on the circuit board 13, the first pins 144 can pass through the corresponding first through holes to limit the fixed position of the first conductive member 14 on the circuit board 13. The first pins 144 facilitate the soldering connection between the first conductive member 14 and the circuit board 13.

[0043] In addition, the second conductive member 15 can be provided with a plurality of second pins 154, which are substantially perpendicular to the second supporting surface, and the plurality of second pins 154 pass through the circuit board 13 from one side of the circuit board 13 to the other side of the circuit board 13. The second conductive member 15 as a whole can be provided in an irregular shape, and at the edge of the second conductive member 15, the plurality of second pins 154 can be formed in a bending form. The circuit board 13 is provided with second through holes corresponding to the second pins 154, and when the second conductive member 15 is placed on the circuit board 13, the second pins 154 can pass through the corresponding second through holes to limit the fixed position of the second conductive member 15 on the circuit board 13. The second pins 154 facilitate the soldering connection between the second conductive member 15 and the circuit board 13.

[0044] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the present application, and in actual application, various changes can be made in form and details without departing from the spirit and scope of the present application.

Claims

1. A battery pack, comprising: The battery pack comprises a housing, multiple battery cells mounted on the housing, a circuit board electrically connected to the battery cells, and an output terminal connected to the circuit board. The battery cells, the circuit board, and the output terminal form a current path, through which electrical energy is input / output. The battery pack further comprises a first conductive element, a second conductive element, and a fuse element located in the current path. The first conductive element and the second conductive element are spaced apart. One end of the fuse element is fixed to the first conductive element, and the other end is fixed to the second conductive element. The fuse element connects the first conductive element and the second conductive element, and a gap exists between the fuse element and the circuit board.

2. The battery pack according to claim 1, characterized in that: The battery pack further includes a positive electrode connecting piece electrically connected to the positive electrode of the battery cell and a negative electrode connecting piece electrically connected to the negative electrode of the battery cell. The output terminal includes a first terminal and a second terminal. The first terminal is connected to the positive electrode connecting piece, and the first conductive element, the second conductive element and the fuse element are located between the negative electrode connecting piece and the second terminal.

3. The battery pack according to claim 2, characterized in that: One end of the first conductive element is connected to the negative electrode connecting piece, and the other end is connected to the fuse element. The first conductive element is provided with a first stepped surface and a first positioning surface that contacts the first stepped surface. One end of the fuse element is provided with a first conductive part, which is located on the first stepped surface and abuts against the first positioning surface.

4. The battery pack according to claim 3, characterized in that: One end of the second conductive element is connected to the second terminal, and the other end is connected to the safety element. The second conductive element is provided with a second stepped surface and a second positioning surface that is in contact with the second stepped surface. The other end of the safety element is provided with a second conductive part, which is located on the second stepped surface and abuts against the second positioning surface.

5. The battery pack according to claim 4, characterized in that: The distance between the edge of the first positioning surface away from the first step surface and the first step surface is 1 mm to 2 mm, and the distance between the edge of the second positioning surface away from the second step surface and the second step surface is 1 mm to 2 mm.

6. The battery pack according to claim 4, characterized in that: The first conductive element is provided with two opposing first limiting parts, which are spaced apart on the first step surface and abut against both sides of the safety element. The second conductive element is provided with two opposing second limiting portions, which are spaced apart on the second step surface and abut against both sides of the safety element.

7. The battery pack according to claim 1, characterized in that: The first conductive element is provided with a plurality of first pins, which pass through the circuit board from one side of the circuit board and extend to the other side of the circuit board.

8. The battery pack according to claim 1, characterized in that: The second conductive element is provided with a plurality of second pins, which pass through the circuit board from one side of the circuit board and extend to the other side of the circuit board.

9. The battery pack according to claim 1, characterized in that: There are multiple safety elements, and the multiple safety elements are arranged in parallel between the first conductive element and the second conductive element.

10. The battery pack according to claim 1, characterized in that: The first conductive element and the second conductive element are disposed at the same end of the circuit board.

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