Vehicle-mounted cut-off unit and battery pack

Abstract

The utility model belongs to the technical field of new energy automobiles, and particularly relates to a vehicle-mounted cut-off unit and a battery pack, which comprise an upper cover, a shell, a PCB (printed circuit board) arranged between the upper cover and the shell, a BDU module assembled on the PCB, and an insertion spring used for connecting the PCB and the BDU module, the BDU module comprises a pin used for leading out signals, the plug spring comprises a horizontal section and a plug-in section which are perpendicular to each other, the plug-in section penetrates through the PCB to be in compression joint with the pin, and the horizontal section abuts against the upper end face of the PCB to form fixed connection. According to the utility model, the size chain tolerance of the whole machine assembly is completely absorbed through the matching of the screws and the holes, the assembly is ensured to be free of difficulty, the reliability is high, the matching of the insertion spring and the pins and the fastening of the screws on the PCB are mature application modes, and large internal stress does not exist.

Description

Technical Field

[0001] The utility model belongs to the technical field of new energy vehicles, and particularly relates to an in-vehicle cut-off unit and a battery pack. Background Technique

[0002] The in-vehicle cut-off unit of new energy vehicles is a key safety component, and its main function is to cut off the connection between the battery and the motor when necessary to ensure the safety of the vehicle and passengers. To meet the requirements of new energy vehicles for high integration and high-efficiency production, the design and production of in-vehicle cut-off units are developing in the direction of wire-free.

[0003] Specifically, the design concept of this new architecture mainly includes two points: one is to highly integrate the battery management system (BMS) and the battery disconnect unit (BDU); the other is to directly insert all control signals into the printed circuit board (PCB) of the BMS by using the pins, plug springs of the relay and customized devices, so as to completely cancel the internal wiring harness of the product, thereby improving production efficiency and reliability.

[0004] However, in the actual production process, products with this new architecture form generally encounter some problems, resulting in a reduction in the yield rate and failing to achieve the expected improvement in production efficiency. These problems mainly include:

[0005] 1. Long tolerance chain and large cumulative tolerance: Due to multiple tolerance links between multiple components such as relays, housings, and PCBs, the overall tolerance chain is long and the cumulative tolerance is large. This may affect the accuracy and reliability of the product.

[0006] 2. Difficult to meet connector tolerance: In order to ensure safe and reliable connection in the in-vehicle environment (long-term vibration cycle), the connectors carrying signals need to meet a large tolerance. However, this is difficult to achieve in actual production or requires a high cost.

[0007] 3. Deformation and uncertainty of relay installation position: When installing the relay, in order to ensure the reliability of the main signal of high voltage and current, the tightening force of the copper bar connection will be very large. This may cause deformation of the relay installation position and an increase in uncertainty.

[0008] 4. Difficult to align and plug the connector during assembly: When the tolerances of product design and assembly cannot meet the connection requirements, it will be difficult to align and plug the connector during assembly, thus affecting production efficiency. Even if it is aligned, there may be large stresses at positions such as device pads, which will further affect the reliability of the product. Summary of the Utility Model

[0009] The purpose of the utility model is to provide an in-vehicle cut-off unit and a battery pack to solve the problems raised in the background technique.

[0010] The present utility model realizes the above object through the following technical solutions:

[0011] In a first aspect, the present utility model provides a vehicle-mounted cut-off unit, which includes an upper cover and a housing, a PCB board disposed between the two, a BDU module assembled on the PCB board, and a plug spring for connecting the PCB board and the BDU module.

[0012] The BDU module includes pins for signal extraction. The plug spring includes a horizontal section and a plugging section that are perpendicular to each other. The plugging section passes through the PCB board and forms a crimp connection with the pins, and the horizontal section abuts against the upper end surface of the PCB board to form a fixed connection.

[0013] Further, the BDU module includes a pre-charge resistor, a pre-charge relay, a heating relay, a heating fuse, a main fuse, and a main relay.

[0014] Further, the vehicle-mounted cut-off unit further includes screws for fixing the plug spring and the PCB board, and the PCB board is provided with threaded seats that cooperate with the screws for screwing.

[0015] Further, any one of welding, crimping, and insert molding on the outer shell of the PCB board is adopted between the threaded seat and the PCB board.

[0016] Further, the horizontal section is welded to the upper end surface of the PCB board to form a fixed connection therewith.

[0017] Further, the connection between the horizontal section and the plugging section is in a smooth arc transition.

[0018] Further, the plugging section includes symmetrically arranged bent portions and a contact portion disposed in the recessed space formed by the two bent portions, and the contact portion elastically contacts the pins.

[0019] Further, the PCB board is respectively provided with a first through-hole for the plugging section to pass through, and the horizontal section is provided with a second through-hole for the screw to pass through.

[0020] In a second aspect, the present utility model provides a battery pack, which includes the vehicle-mounted cut-off unit according to any one of the above.

[0021] The beneficial effects of the present utility model are as follows:

[0022] The present utility model completely absorbs the dimensional chain tolerance of the whole machine assembly through the cooperation of screws and holes, ensuring that the assembly is not difficult and has high reliability. Whether it is the cooperation between the plug spring and the pins, or the screw fastening or welding on the PCB board, they are all mature application methods and there is no large internal stress. The above assembly structure has the advantage of low cost, eliminating the need to set low-tolerance and high-reliability sockets on the PCB board and reducing the process difficulty. Brief Description of the Drawings

[0023] Figure 1 is a schematic diagram of the overall structure of the present utility model.

[0024] Figure 2 is an exploded schematic diagram of the present utility model.

[0025] Figure 3 is a schematic diagram of the relay pin structure in the present utility model.

[0026] Figure 4 is a schematic diagram of one structure of the plug spring in the present utility model.

[0027] Figure 5 is another schematic diagram of the plug spring in the present utility model.

[0028] Figure 6 is a schematic diagram of the structure when the screw and the threaded seat are assembled in the present utility model.

[0029] In the figure: 1. Upper cover; 2. PCB board; 21. First relief hole; 22. Threaded seat; 3. Housing; 31. Pin; 4. Connector; 41. Plug spring; 411. Horizontal section; 412. Insertion section; 413. Second relief hole; 4121. Bending part; 4122. Contact part; 42. Screw; 5. BDU module. Detailed Description of the Embodiments

[0030] The following further describes the present application in detail with reference to the drawings. It is necessary to point out here that the following detailed embodiments are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above application content.

[0031] Embodiment 1

[0032] As Figure 1-6 shown, this embodiment proposes a vehicle-mounted cut-off unit, including an upper cover 1 and a housing 3 (containing devices such as relays inside), a PCB board 2 (BMS main board) disposed between the two, a BDU module 5 assembled on the PCB board 2 (in this embodiment, the BDU module 5 is specifically the electrical components of the vehicle-mounted cut-off unit), and a plug spring 41 for connecting the PCB board 2 and the BDU module 5; the BDU module 5 includes pins 32 for signal extraction (signal pins of the electrical components in the BDU module), the plug spring 41 includes a horizontal section 411 and an insertion section 412 that are perpendicular to each other, the insertion section 412 passes through the PCB board 2 to form a press connection with the pin 32, and the horizontal section 411 abuts against the upper end surface of the PCB board 2 to form a fixed connection.

[0033] Further preferably, the vehicle-mounted cut-off unit further includes a screw 42 for fixing the plug spring 41 and the PCB board 2, and a threaded seat 22 for screw connection with the screw 42 is provided on the PCB board 2. Any one of welding, crimping and insert molding on the outer shell of the PCB board 2 is adopted between the threaded seat 22 and the PCB board 2.

[0034] It can be understood that in this embodiment, the screw 42 is a signal connection screw and the plug spring 41 is a signal connection plug spring. Specifically, the horizontal section 411 of the plug spring 41 is connected to the PCB board 2 through the screw 42 to form a signal connection point, and the insertion section 412 of the plug spring 41 passes through the PCB board 2 and is signal-connected to the pin 32. Among them, the insertion section 412 and the pin 32 are in a matching shape.

[0035] Further preferably, the BDU module 5 at least includes a pre-charge resistor, a pre-charge relay, a heating relay, a heating fuse, a main fuse, and a main relay.

[0036] In some preferred embodiments, the horizontal section 411 can be welded to form a fixed connection with the upper end surface of the PCB board 2. As a specific implementation manner, when the welding connection (that is, the horizontal section 411 of the plug spring 41 is welded to the PCB board 2) is adopted, as long as the position of the horizontal section of the plug spring is on the pad of the PCB board 2, the assembly tolerance requirements can be met (for example, the width of the horizontal section of the plug spring is 10 mm, the width of the pad is 14 mm, and the tolerance is ±2 mm).

[0037] Further preferably, the connection between the horizontal section 411 and the insertion section 412 is in a smooth arc transition. Figure 4 And Figure 5 , the insertion section 412 includes symmetrically arranged bending portions 4121 and an abutting portion 4122 (specifically a spring piece) arranged in the recessed space formed by the two bending portions 4121. The abutting portion 4122 is in elastic contact with the pin 32 to ensure that the plug spring 41 can form a reliable crimping with the pin 32.

[0038] Further preferably, a first relief hole 21 for the insertion section 412 to pass through is provided on the PCB board 2, and a second relief hole 413 for the screw 42 to pass through is provided on the horizontal section 411.

[0039] According to the above embodiments, as a specific implementation, such as the assembly scheme using the screw 42, before the in-vehicle cut-off unit is specifically used, it further includes assembling the plug spring 41. Specifically, the insertion section 412 is passed through the first relief hole 21 to form a crimp with the pin 32, and then the screw 42 is used to fix the plug spring 41 on the PCB board 2 to ensure that the signals of each relay can be introduced into the PCB board. After the scheme is implemented, the main tolerances connected on the PCB board 2 can be absorbed by the cooperation of the holes (the above-mentioned first relief hole 21 and the second relief hole 413) when the screw 42 and the plug spring 41 are assembled. For example: the hole is opened at 5.6 mm, and the screw is M4 (with a diameter of 4 mm and a pitch of 0.7 mm), which can accommodate a tolerance of ±0.8 mm, greatly improving the overall reliability of the system.

[0040] This embodiment also proposes a battery pack, including the in-vehicle cut-off unit as described above, wherein the in-vehicle cut-off unit is the in-vehicle cut-off unit described above. The battery pack has all the beneficial effects of the above-mentioned in-vehicle cut-off unit, which will not be elaborated here.

[0041] More specifically, in this embodiment, the in-vehicle cut-off unit is specifically the interface between the battery pack and the external high-voltage system, and is directly connected to the battery pack through precisely designed electrical connectors (such as high-voltage copper bars, connectors, and wire harness assemblies). This connection ensures the safe transmission and control of high-voltage electrical energy, and at the same time allows the in-vehicle cut-off unit to effectively monitor and manage the battery pack; the above-mentioned in-vehicle cut-off unit performs battery pack functions including but not limited to the following: power-on and power-off control, pre-charge process management, charging process control, and overload and short-circuit protection.

[0042] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A vehicle-mounted disconnection unit, characterized in that: It comprises an upper cover (1) and a housing (3), a PCB board (2) arranged therebetween, a BDU module (5) mounted on the PCB board (2), and an insertion spring (41) for connecting the PCB board (2) and the BDU module (5); The BDU module comprises a plug pin (32) for signal lead-out, the plug spring (41) comprises a horizontal section (411) and a plug section (412) which are perpendicular to each other, the plug section (412) passes through the PCB board (2) to form a crimping connection with the plug pin (32), and the horizontal section (411) abuts against the upper end surface of the PCB board (2) to form a fixed connection.

2. The vehicle-mounted disconnection unit according to claim 1, characterized in that: The BDU module (5) comprises a pre-charging resistor, a pre-charging relay, a heating relay, a heating fuse, a main fuse, and a main relay.

3. The vehicle-mounted disconnection unit according to claim 1, characterized in that: The vehicle-mounted disconnection unit also includes a screw (42) for fixing the plug spring (41) and the PCB board (2), and the PCB board (2) is provided with a threaded seat (22) that is threadedly connected with the screw (42).

4. The vehicle-mounted disconnection unit according to claim 3, characterized in that: The threaded seat (22) and the PCB board (2) are connected by welding, crimping, or embedding and injection molding on the outer shell of the PCB board (2).

5. The vehicle-mounted disconnection unit according to claim 1, characterized in that: The horizontal section (411) is welded to the upper end surface of the PCB board (2) to form a fixed connection therewith.

6. The vehicle-mounted disconnection unit according to claim 1, characterized in that: The connection between the horizontal section (411) and the plug-in section (412) is in a smooth arc transition.

7. The vehicle-mounted disconnection unit according to claim 1, characterized in that: The plug section (412) comprises symmetrically arranged bending portions (4121) and abutment portions (4122) arranged in a recessed space formed by the two bending portions (4121), and the abutment portions (4122) are in elastic contact with the plug pin (32).

8. The vehicle-mounted disconnection unit according to claim 4, characterized in that: The PCB board (2) is provided with a first clearance hole (21) for the plug-in section (412) to pass through, and the horizontal section (411) is provided with a second clearance hole (413) for the screw (42) to pass through.

9. A battery pack, characterized in that: The invention comprises a vehicle-mounted disconnection unit as claimed in any one of claims 1 to 8.

Images