A cylindrical battery fixing device suitable for large current and high power output

Abstract

The application discloses a cylindrical battery fixing device suitable for large-current high-power output, and belongs to the field of battery module assembly, and comprises a fixing bottom plate (1), positive and negative electrode bolt baffle plates (2), positive and negative electrode conductive sheet baffle plates (3), a pull plate (4), an inner thread fastener (5), an outer thread fastener (6) and a conductive sheet (7). Three PCB plates are respectively arranged to independently lay copper wires, and electrical conduction is realized by welding through bottom metallization boss insertion of the first through-hole pad (9) of the bottom plate; the inner thread fastener and the conductive sheet are respectively SMT (surface mount technology) mounted on corresponding pads, and the outer thread fastener is threadedly locked to realize large-plane lamination of two poles of the cylindrical battery; the pull plate is clamped to the grooves on both sides to balance and lock stress. The inner thread fastener is omitted to reduce production cost; the three PCB plates are cooperated to complete series and parallel connection of the cylindrical battery, the contact resistance is small, the voltage loss is low, the cell voltage difference is small, the BMS (battery management system) sampling precision is high; spot welding is omitted, a single cylindrical battery can be individually disassembled, full-automatic SMT mass production is adapted, and the device is suitable for high-rate discharge scenes such as energy storage and industrial power supply.

Description

Technical Field

[0001] This invention relates to the field of cylindrical battery module assembly structure technology, and is particularly applicable to cylindrical battery fixing conductive devices for high-rate, high-current discharge scenarios such as high-power energy storage power supplies, industrial inverters, and high-power electric equipment. Background Technology

[0002] Currently, the mainstream connection solutions for cylindrical battery modules fall into two categories: Spot welding connection solution: The busbar is welded to the positive and negative terminals of the cylindrical battery using resistance welding / laser welding. This method offers low contact resistance but has significant drawbacks: individual cylindrical batteries cannot be removed and replaced individually; the high temperature during welding can easily damage the explosion-proof valve of the cylindrical battery; mass production welding equipment is costly; and scrapped modules cannot be disassembled and recycled, resulting in extremely high subsequent repair and replacement costs. Spring-spring clamping solution: This solution uses elastic metal springs to clamp the cylindrical battery terminals to achieve conductivity. It eliminates the need for spot welding and allows for the disassembly and assembly of the cylindrical battery. However, the springs and terminals only rely on their own elasticity for contact, which cannot apply uniform locking pressure. The contact area is small, and the elasticity is prone to decay over long-term use, making it easy for loose connections to occur. Traditional spring structures have high contact resistance, resulting in high overall contact resistance during high-current output and severe heat generation during operation, which cannot meet the requirements of high-current, high-power discharge. High voltage loss at the contact points of the springs causes voltage sampling distortion in the BMS (Battery Management System), making the system prone to triggering false overcharge and over-discharge protection, resulting in the incomplete utilization of the cylindrical battery capacity.

[0003] Existing solderless cylindrical battery mounting structures mostly employ a single PCB with elastic pressure plates or injection-molded brackets with metal busbars. Electrode matching is generally fixed after shipment, and an integrated structure combining low contact resistance, independent disassembly and assembly, and suitability for automated mass production has yet to emerge. Current technologies cannot simultaneously achieve fully automated SMT (Surface Mount Technology) mass production, large-area low-resistance contact through locking and pressurization, uniform locking stress, and low voltage loss with high-precision BMS sampling. Furthermore, existing technologies cannot simultaneously address the six technical challenges of high current with low heat generation, solderless mounting, individual replacement of cylindrical batteries, flexible electrode selection, automated production, uniform locking stress, and low voltage loss in the module for accurate BMS sampling. Summary of the Invention

[0004] Purpose of the invention Addressing issues such as the non-removable spot welding structure, high contact resistance and severe overheating due to unstable locking pressure of spring contacts, the inability of traditional PCB fixing structures to connect three PCB boards, large dispersion of module internal resistance, and BMS... Addressing the shortcomings of low voltage sampling accuracy and the inability to automate SMT assembly, this invention provides a cylindrical battery mounting device suitable for high-current, high-power output applications. It achieves seamless, large-area conductive bonding without spot welding, relying on external threaded fasteners for locking and pressure application. During the device design and manufacturing phase, the internal threaded fasteners and conductive sheets can be switched to correspond to the positive and negative terminals of the cylindrical battery by adjusting the copper trace layout within the PCB. Once the product is finalized, the electrode matching relationship cannot be changed. Electrical conductivity is achieved across the three PCBs via bosses and through-hole pads, ensuring uniform locking stress, fully automated SMT assembly, and independent disassembly and maintenance of individual cylindrical batteries. It significantly reduces overall contact resistance; the contact resistance of each individual battery cell is extremely low, effectively reducing voltage loss from the cylindrical battery to the BMS sampling circuit, lowering the voltage difference between the cylindrical battery and the BMS system, ensuring the voltage acquisition accuracy of the BMS system, and adapting to high-power, high-current output scenarios.

[0005] Technical solution A cylindrical battery fixing device suitable for high current and high power output applications includes a fixing base plate (1), positive and negative electrode bolt baffles (2), positive and negative electrode conductive sheet baffles (3), a pull plate (4), internal thread fasteners (5), external thread fasteners (6), and conductive sheets (7). The fixed base plate (1), positive and negative electrode bolt baffle (2), and positive and negative electrode conductive sheet baffle (3) are three PCB boards. The fixed base plate (1) is provided with at least one pair of first through hole pads (9). Each set of first through hole pads (9) is respectively equipped with a positive and negative electrode bolt baffle (2) and a positive and negative electrode conductive sheet baffle (3). The three PCB boards together constitute the main conductive structure; the bottom of the positive and negative electrode bolt baffle (2) is provided with at least one first reserved boss (12), and the bottom of the positive and negative electrode conductive sheet baffle (3) is provided with at least one second reserved boss (15); the body of the first reserved boss (12) and the second reserved boss (15) is a PCB substrate, which is formed by surface metallization treatment to form a continuous metal layer. This metal layer realizes electrical conduction on the one hand, and improves surface solderability on the other hand, which facilitates wave soldering soldering; the outer contour size of the first reserved boss (12) and the second reserved boss (15) is slightly smaller than the inner contour size of the first through hole pad (9). During assembly, after inserting the first through hole pad (9), it is soldered by wave soldering. The three PCB boards realize electrical conduction by relying on the boss and the through hole pad, and the mechanical fixation and electrical connection of the three PCB boards are completed simultaneously. The positive and negative electrode bolt baffle (2) has at least one second through hole pad (11) on its surface. The second through hole pad (11) is a through hole for surface mount bearing on the PCB. This device is designed with two threaded connection implementation routes: Route 1 (Standard Mass Production Scheme): The internal thread fastener (5) is mounted on the second through hole pad (11) board surface as a standard SMT component; the flat conductive surface (18) of the internal thread fastener is attached to the second through hole pad (11) to complete the PCB conductive connection; the external thread fastener (6) passes through the through hole of the second through hole pad (11) and only forms a threaded tightening and pressure fit with the internal thread fastener (5); Route 2 (Low-cost simplification solution): Eliminate the independent internal thread fastener (5), directly process the internal thread on the inner wall of the through hole of the second through hole pad (11), the metallization layer of the inner wall of the through hole completely covers the internal thread tooth surface, forming a continuous conductive thread structure, the external thread fastener (6) directly meshes with the internal thread of the through hole and conducts current by relying on the thread contact surface, eliminating the need for metal surface mount accessories, reducing the types of materials and SMT surface mount process, and reducing the overall production cost; The positive and negative electrode conductive sheet baffle (3) has at least one surface mount pad (14) on its surface. The conductive sheet (7) is fixed to the surface mount pad (14) by SMT reflow soldering. The outer side of the conductive sheet has an integrally formed flat contact surface (19). The positive and negative electrode bolt baffle (2) has multiple first grooves (10) on its side, and the positive and negative electrode conductive sheet baffle (3) has multiple second grooves (13) on its side; the pull plate (4) has multiple locking grooves (16). During assembly, the locking grooves (16) are simultaneously embedded in the first grooves (10) and the second grooves (13) to form a lateral limit on the two PCB baffles; during the tightening and pressurization of the external thread fasteners, the pull plate (4) evenly disperses the pressing force on both sides of the baffles to avoid local stress concentration on the PCB causing board warping and solder pad detachment; The external threaded fastener (6) has an integrally formed flat conductive surface (17) at the head of the external threaded fastener; the flat conductive surface (17) at the head of the external threaded fastener and the flat contact surface (19) of the conductive sheet are both flat planes. Under the locking and pressure of the external threaded fastener, they are seamlessly attached to the two large areas of the cylindrical battery. The corresponding electrodes of the two can be freely interchanged during the design and manufacturing stage. During the design phase, the flat conductive surface (17) of the external threaded fastener head can be connected to the positive terminal of the cylindrical battery, and the flat contact surface (19) of the conductive sheet can be connected to the negative terminal of the cylindrical battery; alternatively, the design can be reversed, with the flat conductive surface (17) of the external threaded fastener head connected to the negative terminal of the cylindrical battery and the flat contact surface (19) of the conductive sheet connected to the positive terminal of the cylindrical battery. Both polarity assembly methods are applicable. The three PCB boards are each laid with independent copper traces, and the three PCB boards achieve electrical conduction by relying on bosses and through-hole pads, and cooperate to complete the series boost and parallel capacity expansion of multiple cylindrical batteries. Furthermore, the internal thread fastener (5) supports patch assembly, and the flat conductive surface (18) of the internal thread fastener is attached to the second through hole pad (11) of the board surface; the external thread fastener (6) can be selected from various specifications such as cross type, slotted type, and internal hexagonal type, and provides uniform clamping force after tightening. The entire device is a standalone set, excluding the cylindrical battery (8), which is a standard accessory purchased from outside.

[0006] Beneficial effects (1) Achieve extremely low contact resistance, continuous operation at high current without heat generation and low voltage loss: The head of the external thread fastener and the conductive sheet are complete planes, which are in close contact with the two large areas of the cylindrical battery after locking and pressurizing; The three PCB boards are reliably connected by metallized bosses and through-hole pads, the conductive path is complete, the contact resistance is much lower than that of the traditional spring sheet structure, the temperature rise is extremely low during long-term high-power operation, and the voltage loss is extremely small. (2) The cell voltage difference is extremely low and the BMS voltage sampling accuracy is high: the conductive structure of each cylindrical battery and the conduction mode of the three PCB boards are uniform, the impedance of each branch is highly consistent, the cell voltage difference is small, the BMS voltage sampling error is low, and the battery balancing and thermal protection control accuracy are significantly improved. (3) Flexible electrode selection and stable finished product structure: During the design phase, the internal thread fasteners and conductive sheets can be switched to correspond to the positive and negative electrodes of the cylindrical battery by adjusting the layout of the copper traces inside the PCB. (4) Completely free of spot welding, cylindrical batteries can be disassembled and assembled independently: relying on internal and external threads to conduct electricity, no welding is required; if a single cylindrical battery fails, it can be replaced by simply removing the corresponding external thread fastener; the module can be completely disassembled and the cylindrical batteries can be recycled. (5) Adapted to fully automated SMT mass production: Metallized bosses can be fixed by wave soldering and through-hole pads, and internal thread fasteners and conductive sheets can be placed in one SMT process. Automated production line processing reduces labor and production costs. (6) Reliable interconnection of three PCB boards: The three PCB boards are connected by metallized bosses and through-hole pads, without the need for additional jumper wires, resulting in simple wiring and compact structure; (7) Balanced locking stress, PCB is not easily damaged: The pull plate has multiple limiting points to disperse the locking stress and prevent PCB warping and pad detachment; (8) Strong versatility: It is compatible with cylindrical batteries of specifications such as 18650, 21700, and 26650. The specifications and dimensions of the fixing base plate (1), positive and negative electrode bolt baffle (2), positive and negative electrode conductive sheet baffle (3), pull plate (4), internal thread fastener (5), external thread fastener (6), and conductive sheet (7) can be adjusted according to the specifications and dimensions of different cylindrical batteries to adapt to more specifications of cylindrical batteries; the metallization process of the boss and the number of various solder pads can be adjusted as needed to adapt to energy storage, vehicle-mounted, and high-power electric equipment; (9) Low-cost simplified solution with flexible selection to adapt to different application needs: The simplified solution with integrated internal thread on the wall of the second through hole pad can eliminate the need for independent internal thread fasteners, reduce the types of materials and SMT placement process, effectively reduce material and processing production costs, and make the automated production process simpler; The internal thread of this solution is directly formed on the PCB substrate, and the structural strength is weaker than that of independent metal internal thread fasteners. The locking pressure that it can withstand has an upper limit. The overall overcurrent capacity and long-term repeated disassembly and assembly durability are lower than the standard mass production solution. It is suitable for cost-sensitive application scenarios with moderate discharge rate and disassembly and assembly frequency. Attached Figure Description

[0007] Figure 1 This is a three-dimensional schematic diagram of the assembled invention; Figure 2 A schematic diagram of a separate structure for a fixed base plate with at least one pair of first through-hole pads and a PCB substrate; Figure 3 A schematic diagram of a separate structure for a positive and negative electrode bolt baffle with at least one first reserved boss at the bottom, at least one second through hole pad on the plate surface, and multiple first grooves on the side. Figure 4 A schematic diagram of a separate structure of a positive and negative electrode conductive sheet baffle with at least one second reserved boss at the bottom, at least one surface mount pad on the board surface, and multiple second grooves on the side. Figure 5 A schematic diagram of a separate structure for a pull plate with multiple engagement slots; Figure 6 A schematic diagram of a separate structure for an internally threaded fastener; Figure 7 This is a schematic diagram of a separate structure for an externally threaded fastener; Figure 8 This is a schematic diagram of the individual structure of the conductive sheet; Figure 9 This is an exploded view of the entire invention after the cylindrical battery is assembled. Figure 10 A schematic diagram of a structure in which an internal threaded fastener is SMT mounted on a second through-hole pad and an external threaded fastener is assembled. Figure 11 This is an assembly diagram showing how conductive sheets are fixed to surface mount pads via SMT (Surface Mount Technology).

[0008] In the diagram: 1-Fixed base plate (PCB substrate); 2-Positive and negative electrode bolt baffles (PCB substrate); 3-Positive and negative electrode conductive sheet baffles (PCB substrate); 4-Pull plate; 5-Internal threaded fastener; 6-External threaded fastener; 7-Conductive sheet; 8-Cylindrical battery; 9-First through-hole pad (at least one pair is provided on the fixed base plate for connecting the three PCB boards); 10-First groove (multiple grooves are provided on the side of the positive and negative electrode bolt baffles); 11-Second through-hole pad (at least one is provided on the surface of the positive and negative electrode bolt baffles, serving as a through-hole for surface mount support); 12-First reserved boss (at least one is provided at the bottom of the positive and negative electrode bolt baffles, inserted into the first through-hole pad to connect the three PCB boards). 13-Second groove (multiple grooves are provided on the side of the positive and negative conductive sheet baffle); 14-Surface mount pad (at least one is provided on the surface of the positive and negative conductive sheet baffle); 15-Second reserved boss (at least one is provided at the bottom of the positive and negative conductive sheet baffle, which is inserted into the first through hole pad to achieve conductivity between the three PCB boards); 16-Mounting groove (multiple grooves are provided on the pull plate); 17-Flat conductive surface of the head of the external threaded fastener (can be configured to connect to any pole of the cylindrical battery during the design stage); 18-Flat conductive surface of the internal threaded fastener (single-sided PCB mounting, does not contact the cylindrical battery); 19-Flat contact surface of the conductive sheet (can be configured to connect to any pole of the cylindrical battery during the design stage, and the finished product corresponds to a single electrode). Detailed Implementation

[0009] In the embodiments, "electroplated gold, electroplated silver, electroplated nickel, and electroplated tin" all refer to "surface metallization coatings"; "internal hexagon set screws, Phillips head screws, and external hexagon screws" all refer to "external thread fasteners"; the size specifications in the embodiments are roughly selected based on the diameter and height of the cylindrical battery and the positive and negative electrode contact surfaces.

[0010] Example 1: Parallel operation (all cylindrical batteries face the same direction, the fixed base plate only serves as a mechanical fixation and does not participate in current conduction) The complete set does not include cylindrical batteries (8), and is compatible with 21700 cylindrical batteries. The external thread fasteners (6) are M10*8 socket head cap screws with a pitch of 1mm. The conductive sheet (7) is a copper-based gold-plated sheet with a cylindrical shape, a thickness of 1mm, and a diameter of 10mm. The internal thread fasteners (5) are copper-based hexagonal nuts with a specification of M10*2.4, a pitch of 1mm, and a distance between flats of 12mm. The surface is gold-plated for easy SMT. The PCB copper layer thickness is 1 ounce. The base plate of the three PCB boards is mechanically fixed to the two baffles by the first through hole pad (9), the second reserved boss (15), and the first reserved boss (12). There is no conductive copper inside that participates in the parallel current transmission, and it only undertakes the functions of positioning, bearing and fixing. The positive and negative electrode bolt baffles (2) are covered with a continuous copper layer. All internal threaded fasteners (5) are connected to the positive electrode of the cylindrical battery through the PCB copper layer of the positive and negative electrode bolt baffles (2). The positive and negative electrode conductive sheet baffles (3) are covered with a continuous copper layer. All conductive sheets (7) are connected to the negative electrode of the cylindrical battery through the PCB copper layer of the positive and negative electrode conductive sheet baffles (3). Current path: Positive electrode of single cylindrical battery (8) → Flat conductive surface of external threaded fastener head (17) → External threaded fastener (6) → Thread meshing surface → Internal threaded fastener (5) → Flat conductive surface of internal threaded fastener (18) → Copper plating of positive and negative electrode bolt baffles throughout → Parallel current convergence of all cylindrical battery positive electrodes, parallel current convergence of all cylindrical battery (8) negative electrodes → Copper plating of positive and negative electrode conductive sheet baffles throughout → Conductive sheet (7) → Flat contact surface of conductive sheet (19) → Negative electrode of single cylindrical battery (8); The current of the entire parallel circuit is completely converged within the positive and negative electrode bolt baffles (2) and positive and negative electrode conductive sheet baffles (3), and no current flows into the fixed base plate. Assembly polarity uniformity: the positive pole of all cylindrical batteries faces the positive and negative pole bolt baffle (2) side, and the negative pole faces the positive and negative pole conductive sheet baffle (3) side; the pull plate (4) engages with the first groove (10) and the second groove (13) on both sides to disperse the locking stress, and each cylindrical battery is independently pressed by a set of internal and external thread fasteners. If a single battery is damaged, it can be disassembled and installed separately without affecting the other parallel cylindrical batteries.

[0011] Example 2: Interleaved series connection (adjacent cylindrical batteries, one positive and one negative, fixed base plate is only mechanically fixed and non-conductive) The complete set does not include cylindrical batteries (8), but is compatible with 18650 cylindrical batteries. The external thread fasteners (6) are M6*6 cross-head screws with a pitch of 0.8mm. The conductive sheet (7) is a copper-based silver-plated square sheet with a thickness of 0.8mm and a side length of 6mm. The internal thread fasteners (5) are stainless steel cylindrical nuts with a specification of M6*2, a pitch of 0.8mm, and an outer diameter of 10mm. The surface is electroplated with nickel for easy SMT. The PCB copper thickness is 1.5 ounces. Cylindrical batteries are arranged in an alternating pattern, with adjacent batteries having opposite polarities: the first battery's positive terminal faces the positive and negative terminal bolt baffle (2), and the negative terminal faces the positive and negative terminal conductive sheet baffle (3); the next battery's negative terminal faces the positive and negative terminal bolt baffle (2), and the positive terminal faces the positive and negative terminal conductive sheet baffle (3); the fixing base plate in the three PCB boards is mechanically fixed to the two baffles by the first through-hole pad (9), the second reserved boss (15), and the first reserved boss (12). There is no conductive copper inside that participates in the series current transmission; it only undertakes the functions of positioning, bearing and fixing. The positive and negative electrode bolt baffles (2) are segmented with copper, and the two adjacent sets of internal threaded fasteners (5) are respectively connected to the positive electrode of the previous battery and the negative electrode of the next battery; the positive and negative electrode conductive sheet baffles (3) are segmented with copper, and the two adjacent sets of conductive sheets are respectively connected to the negative electrode of the previous battery and the positive electrode of the next battery; the positive and negative electrodes of the adjacent batteries are connected in series by directly overlapping the segmented copper sheets of the two baffles. Current path: Positive electrode of the first cylindrical battery → external thread fastener (6) → internal thread fastener (5) → copper sheet of positive and negative electrode bolt baffle → internal thread fastener (5) of the second cylindrical battery → external thread fastener (6) of the second cylindrical battery → negative electrode of the adjacent second cylindrical battery → inside the second battery → positive electrode of the second battery → conductive sheet (7) → copper sheet of positive and negative electrode conductive sheet baffle → conductive sheet (7) → negative electrode of the next cylindrical battery, and so on in series. The current flows only between the two electrode baffles, and no current passes through the fixed base plate. Disassembly and assembly characteristics: For a single cylindrical failure, only the corresponding set of internal and external threaded fasteners needs to be disassembled, without disassembling the entire module.

[0012] Example 3: Series connection in the same direction (all cylindrical batteries have the same polarity, and the fixed base plate participates in the series connection across the baffle) The complete set does not include cylindrical batteries (8), and is compatible with 26650 cylindrical batteries. The external thread fasteners (6) are M12*10 hexagonal screws with a pitch of 1mm. The conductive sheet (7) is a stainless steel substrate electroplated with nickel hexagonal metal sheet with a thickness of 1.2mm and a diameter of 12mm. The internal thread fasteners (5) are copper surface mount nuts with an internal thread of M12*2.5, a step height of 1mm, a total height of 2.5mm, a pitch of 1mm, and an outer diameter of 15mm. The surface is tin-plated for easy SMT. The PCB copper thickness is 2 ounces. All cylindrical batteries have their positive terminals aligned with the positive and negative electrode bolt baffles (2) and their negative terminals aligned with the positive and negative electrode conductive sheet baffles (3), arranged in the same direction to avoid the risk of manual reverse installation. At this time, the positive and negative electrode bolt baffles (2) and the positive and negative electrode conductive sheet baffles (3) alone cannot bridge the positive and negative terminals of adjacent batteries. The fixed base plate (1) is laid with cross-section copper traces. The electrical connection with the positive and negative electrode bolt baffles (2) is achieved by soldering the first through hole pad (9) and the first reserved boss (12). The electrical connection with the positive and negative electrode conductive sheet baffles (3) is achieved by soldering the first through hole pad (9) and the second reserved boss (15), which undertakes the series cross-baffle conductive function. Current path: Positive electrode of the first cylindrical battery → external thread fastener (6) → internal thread fastener (5) → copper plating on the surface of the positive and negative electrode bolt baffle (2) → first reserved boss (12) → first through hole pad (9) → series copper plating trace of the fixed base plate (1) → first through hole pad (9) corresponding to the second cylindrical battery → second reserved boss (15) corresponding to the second cylindrical battery → copper plating on the surface of the positive and negative electrode conductive sheet baffle (3) → conductive sheet (7) → negative electrode of the second cylindrical battery; and so on, the copper sheet of the fixed base plate (1) realizes the series connection of the next positive electrode and the next negative electrode across the baffle in the same direction. The three PCB boards have different functions: the positive and negative electrode bolt baffles collect the positive current of a single section, the positive and negative electrode conductive sheet baffles collect the negative current of a single section, and the fixed base plate completes the series connection from the positive electrode of the previous section to the negative electrode of the next section through independent copper pouring; the pull plate continuously balances the locking pressure to prevent multiple PCBs arranged in the same direction from warping under stress and the solder pads from falling off.

[0013] Example 4: Implementation route two of the thread fit technical solution, simplified structural working condition with integrated internal thread (low-cost solution) The entire device does not include cylindrical batteries (8). It adopts the low-cost simplification scheme of technical solution route two, eliminating the independent internal thread fasteners (5). When machining the inner wall of the through hole pad (11) of the positive and negative electrode bolt baffles (2), it is directly machined into a metal internal thread. The external thread fasteners (6) directly engage with the internal thread to conduct electricity, eliminating the need for metal surface mount accessories, reducing materials and SMT placement processes, and lowering production costs. The module series-parallel arrangement method in this embodiment can directly adopt any of the arrangement structures in Embodiments 1 to 3. The specific current path skips the internal thread fastener (5). Because the thread is formed on the PCB substrate, the structural strength of the substrate is weaker than that of the internal thread fastener (5) which uses an independent metal material. The clamping force that can be applied when the external thread fastener (6) is locked has an upper limit, which makes it impossible to achieve high pressure clamping and conductivity. The overall overcurrent capacity of the device is lower than that of other embodiments equipped with independent internal thread fasteners. The durability of long-term repeated disassembly and assembly is also relatively poor. During assembly, the pull plate (4) is engaged with the grooves of the baffles on both sides to evenly distribute the locking stress and alleviate the stress deformation of the PCB threaded parts; only the conductive sheet (7) needs to be SMT mounted, making the automated production process simpler.

[0014] Additional notes: The shape, thickness, number of boss pads, metallization plating process, and fastener specifications of each component can be flexibly adjusted according to different specifications of cylindrical batteries such as 18650 / 21700 / 26650 / 32650 / 46120 and their output power. The boss, pad spacing, and fastener specifications can be adjusted according to the size of, for example, a 32650 cylindrical battery to accommodate larger cylindrical batteries. All equivalent substitution schemes based on this structure fall within the protection scope of this invention. All embodiments of this invention are not intended to limit the purpose and scope of protection of this invention, and there may be more implementation methods. Only some of the embodiments are listed here.

Claims

1. A cylindrical battery fixing device suitable for high current and high power output applications, characterized in that, Includes a fixed base plate (1), positive and negative electrode bolt baffles (2), positive and negative electrode conductive sheet baffles (3), pull plate (4), internal thread fasteners (5), external thread fasteners (6), and conductive sheet (7); The fixed base plate (1), positive and negative electrode bolt baffles (2), and positive and negative electrode conductive sheet baffles (3) are three PCB boards. The fixed base plate (1) is provided with at least one pair of first through-hole pads (9). The three PCB boards together constitute the main conductive structure. The bottom of the positive and negative electrode bolt baffles (2) is provided with at least one first reserved boss (12), and the bottom of the positive and negative electrode conductive sheet baffles (3) is provided with at least one second reserved boss (15). The first reserved boss (12) and the second reserved boss (15) The surface is metallized to form a continuous metal layer, which has the functions of being conductive and facilitating SMT soldering; the outer contour dimensions of the first reserved boss (12) and the second reserved boss (15) are smaller than the inner contour dimensions of the first through hole pad (9), and they are respectively inserted into the first through hole pad (9) and fixed by soldering; the three PCB boards are respectively laid with independent copper traces, and the three rely on the bosses and through hole pads to achieve mechanical fixation and electrical conduction, and cooperate to complete the series and parallel arrangement of multiple cylindrical batteries; The positive and negative electrode bolt baffle (2) is provided with at least one second through hole pad (11) on its plate surface. The internal thread fastener (5) is mounted on the plate surface corresponding to the second through hole pad (11) by SMT surface mount technology. The flat conductive surface (18) of the internal thread fastener is only attached to the second through hole pad (11) on one side to achieve conductive connection. The external thread fastener (6) is inserted into the through hole of the second through hole pad (11) and forms a threaded engagement conductive fit with the internal thread fastener (5). The positive and negative electrode conductive sheet baffle (3) is provided with at least one surface mount pad (14), and the conductive sheet (7) is fixed to the surface mount pad (14) by SMT surface mount process. The conductive sheet has a flat contact surface (19) on the side away from the positive and negative electrode conductive sheet baffle (3). The positive and negative electrode bolt baffle (2) has multiple first grooves (10) on its side, and the positive and negative electrode conductive sheet baffle (3) has multiple second grooves (13) on its side. The pull plate (4) has multiple engaging grooves (16). The engaging grooves (16) engage the first grooves (10) and the second grooves (13) at the same time, balancing the clamping force generated during the locking of the cylindrical battery by the external thread fastener, and forming a lateral limit on the positive and negative electrode bolt baffle (2) and the positive and negative electrode conductive sheet baffle (3). The end of the external threaded fastener (6) is provided with a flat conductive surface (17) at the head of the external threaded fastener; the flat conductive surface (17) at the head of the external threaded fastener and the flat contact surface (19) of the conductive sheet are planar structures, and are seamlessly attached to the two poles of the cylindrical battery by locking and pressurizing the external threaded fastener; the current of one pole of a single cylindrical battery is conducted to the positive and negative pole bolt baffle (2) through the external threaded fastener (6), the thread meshing contact surface, the internal threaded fastener (5), and the flat conductive surface (18) of the internal threaded fastener in sequence; the contact resistance between the cylindrical battery and the contact surface of the external threaded fastener (6) and the conductive sheet (7) is extremely low, the voltage loss is small, and it can provide a high-precision voltage sampling signal for the BMS system; During the device design and manufacturing stage, by adjusting the internal copper trace layout of the three PCB boards, the flat conductive surface (17) of the external threaded fastener head and the flat contact surface (19) of the conductive sheet are adapted to the positive and negative poles of the cylindrical battery (8), and the polarity of the two connected batteries can be interchanged.

2. A cylindrical battery fixing device suitable for high-current, high-power output applications, characterized in that, The difference between this and claim 1 is that the independently set internal thread fastener (5) is cancelled, the second through hole welding pad (11) of the positive and negative pole bolt baffle (2) is processed into an internal thread through the inner wall of the hole, and the external thread fastener (6) directly engages with the internal thread to conduct electricity.

3. The cylindrical battery fixing device suitable for high-current, high-power output applications according to claim 1, characterized in that, The internal thread fastener (5) is a patch-type metal standard part. The flat conductive surface (18) of the internal thread fastener is attached to the second through hole pad (11) to complete the conductive connection.

4. The cylindrical battery fixing device suitable for high-current, high-power output applications according to claim 1 or 2, characterized in that, The surface metal layer of the first reserved boss (12) and the second reserved boss (15) can be prepared by any surface metallization plating process.

5. The cylindrical battery fixing device suitable for high-current, high-power output applications according to claim 1 or 2, characterized in that, The external threaded fastener (6) is any one of cross screw, slotted screw, internal hexagonal set screw, or external hexagonal screw. The flat conductive surface (17) of the head of the external threaded fastener is complete and without gaps. Under the locking pressure of the external threaded fastener, it fits seamlessly with one of the poles of the cylindrical battery.

6. The cylindrical battery fixing device suitable for high-current, high-power output applications according to claim 1 or 2, characterized in that, The locking groove (16) of the pull plate (4) is fitted with the first groove (10) and the second groove (13) to form a lateral limit on the positive and negative electrode bolt baffle (2) and the positive and negative electrode conductive sheet baffle (3) to prevent the PCB baffle from shifting and deforming when locking and pressurizing.

7. The cylindrical battery fixing device suitable for high-current, high-power output applications according to claim 1 or 2, characterized in that, The entire device does not include cylindrical batteries (8).

8. The cylindrical battery fixing device for high-current, high-power output applications according to claim 1 or 2, characterized in that, This device relies on external threaded fasteners to lock and pressurize, forming a conductive structure that presses the two poles of the cylindrical battery together. It can complete the electrical connection of the cylindrical battery module without spot welding or additional busbars.

9. The cylindrical battery fixing device for high-current, high-power output applications according to claim 1 or 2, characterized in that, The fixed base plate (1) is provided with series copper traces that bridge the positive and negative electrode bolt baffles and the positive and negative electrode conductive sheet baffles. The traces are welded and fixed to the bosses of the positive and negative electrode bolt baffles (2) and the positive and negative electrode conductive sheet baffles (3) through the first through hole pad (9).

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