A power battery upper box and a design method

Abstract

The application discloses a kind of power battery upper box and design method, belong to vehicle technical field, including upper box body, structural reinforcement coating, fireproof thermal insulation coating, moisture barrier pressure relief structure and monitoring system;Structural reinforcement coating is bonded to the outside of upper box body;Fireproof thermal insulation coating is bonded to the inside of upper box body, moisture barrier pressure relief structure is screwed on the moisture barrier structure mounting surface, monitoring system is placed on the monitoring system mounting surface of upper box body.The application pastes structural reinforcement, environmental thermal insulation, fireproof material inside and outside upper box, can meet the load demand of upper box, effectively control the spread of fire when power battery thermal runaway, carry moisture barrier explosion-proof structure to carry out moisture barrier, while built-in temperature sensor, sealed flange surface pressure sensor, carry out temperature monitoring and fastening bolt torque attenuation monitoring in battery pack, the upper box is highly integrated, multi-level, multi-functional, with load, fireproof, moisture barrier, dynamic detection and other functions of power battery upper box.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vehicles, and particularly relates to a power battery upper box and a design method. BACKGROUND

[0002] New energy vehicles have the advantages of green environmental protection, and the power battery develops rapidly, but each part has simple structure, single function and cannot be integrated. As an important part of the power battery, the upper box needs to meet higher requirements with the development of the industry, not only needs to meet the sealing requirement, but also needs to have the functions of load bearing capacity, heat preservation and fire prevention.

[0003] At present, electric vehicles develop rapidly, and the arrangement position of the power battery is diversified, not only limited to the bottom of the whole vehicle, and part of the PHEV / HEV vehicle type arranges the power battery in the rear luggage compartment. The luggage compartment needs to bear a certain weight of articles, so the power battery upper box needs to meet the load bearing requirement, and at the same time, due to the change of the placement position, the power battery and the driver cabin passenger are in the same sealed space, higher requirements need to be put forward for the power battery thermal runaway, so as to meet the timely triggering of the alarm system and effectively inhibit the spread of fire when the thermal runaway occurs, and provide enough time for the passengers to abandon the car. Due to the air conditioning circulation in the vehicle cabin and the personnel breathing, the humidity in the vehicle is large, and the power battery should have good sealing and moisture blocking effect. The bolt torque attenuation condition is not easy to be detected, and the torque attenuation condition needs to be directly monitored.

[0004] In summary, the power battery sealing has always been difficult to monitor, the internal water inflow is not easy to be detected, the real-time monitoring function needs to be provided and interconnected with the vehicle end, and the driver is reminded of the safety state of the power battery. SUMMARY

[0005] In view of the above problems existing in the prior art, the purpose of the present application is to provide a power battery upper box and a design method. The present application is pasted with structure reinforcement, environmental heat preservation and fireproof material inside and outside the upper box, can meet the load bearing requirement of the upper box, effectively control the spread of fire when the power battery thermal runaway occurs, carry the moisture blocking and explosion prevention structure for moisture blocking, at the same time, the temperature sensor and the sealing flange surface pressure sensor are built in, the temperature in the battery pack is monitored, and the tightening bolt torque attenuation is monitored. The upper box is highly integrated, multi-level and multifunctional, and has the functions of load bearing, fire prevention, moisture blocking, dynamic detection and the like.

[0006] The present application is realized by the following technical scheme:

[0007] The first aspect of the present application provides a power battery upper box, comprising an upper box body 1, a structure strengthening coating 2, a fireproof and heat preservation coating 3, a moisture-proof pressure relief structure 4 and a monitoring system 5; the structure strengthening coating 2 is bonded to the outer side of the upper box body 1, the fireproof and heat preservation coating 3 is bonded to the inner side of the upper box body 1, the moisture-proof pressure relief structure 4 is screwed on the moisture-proof structure mounting surface 11 of the upper box body 1, and the monitoring system 5 is arranged on the monitoring system mounting surface 15 of the upper box body 1.

[0008] Further, the upper surface of the upper box body 1 is provided with a moisture-proof structure mounting surface 11, a sealing surface lower edge strengthening feature 12, a gas sealing structure 13, sealing glue, a strength strengthening coating 15 and a monitoring system mounting surface 16; the moisture-proof structure mounting surface 11 is used for mounting the moisture-proof pressure relief structure 4, the sealing flange surface edge of the upper box body 1 is provided with the sealing surface lower edge strengthening structure 12 for improving the sealing edge strength and reducing the installation deformation; the gas sealing structure 13 is located inside the sealing flange surface edge of the upper box body 1 and is used for limiting the shape of the sealing glue to form a regular-shaped sealing glue layer; the sealing glue is located inside the gas sealing structure 13; the structure strength strengthening coating 15 is located outside the upper box body 1 and is used for bonding the structure strengthening coating 2; the monitoring system mounting surface 16 is located inside the upper box body 1 and is used for mounting temperature sensors and pressure sensors; the monitoring system mounting surface 16 for mounting the temperature sensors is located at the corresponding positions of the highest point and the lowest point of the overall temperature, and the monitoring system mounting surface 16 for mounting the pressure sensors is located at the position of the obvious torque attenuation area of the overall package; the sealing flange is connected with the lower box by bolts to form the internal space of the power battery.

[0009] Further, the moisture-proof structure mounting surface 11 is located at the weak position of the structure strength of the upper box body 1 and is composed of a boss mounting plane and a sealing ring groove; the length of the edge of the sealing surface lower edge strengthening structure 12 is greater than or equal to 1 mm; the gas sealing structure 13 is located inside the sealing flange surface edge of the upper box body 1 by 8-15 mm and is a trapezoidal groove sealing structure with a trapezoidal short side length greater than or equal to 3 mm, an opening width greater than or equal to 8 mm and a depth greater than or equal to 3 mm; the depth of the structure strength strengthening coating 15 is 2-5 mm, the length is 100-1000 mm, the width is 10-100 mm, and the shape is rectangular; the monitoring system mounting surface 16 is a square with a depth of 0.5-1.5 mm and a side length of 2±1 mm.

[0010] Further, the strength reinforcing coating 2 is bonded to the outer side of the upper cabinet body 1, and comprises a first reinforcing coating and a second reinforcing coating; the first reinforcing coating is bonded to the inner side of the structure reinforcing coating 15 of the upper cabinet body 1, and the second reinforcing coating is coated between the coating intervals of the first reinforcing coating 21; both the first reinforcing coating 21 and the second reinforcing coating 22 are used to strengthen the structure strength of the upper cabinet assembly and enhance the load-bearing capacity of the upper cabinet.

[0011] Further, the thickness of the first reinforcing coating is 1.5-3.0 mm, the width is 15-40 mm, the coating interval is not less than 30 mm, and the material is carbon fiber; the thickness of the second reinforcing coating is 1.0-2.5 mm, the width is ≥30 mm, and the material is diamond-like carbon (DLC) coating.

[0012] Further, the fireproof and heat-insulating coating 3 is arranged on the inner side of the upper cabinet body 1, and comprises, from top to bottom, a first heat-insulating coating 31, a second heat-insulating coating 32, and a fireproof coating 33; the first heat-insulating coating 31 completely covers the inner surface of the upper cabinet body 1, has a thickness of 3-6 mm, and is made of polypropylene foam plastic; the second heat-insulating coating 32 completely covers the inner surface of the first heat-insulating coating 31, has a thickness of 4-6 mm, and is made of polyurethane foam plastic; and the fireproof coating 33 completely covers the inner surface of the second heat-insulating coating 32, has a thickness of 1-3 mm, and is made of mica material.

[0013] Further, the moisture-proof pressure relief structure 4 comprises an upper cover 41, a moisture-proof diaphragm 42, a support structure 43, and a sealing ring 44; the upper cover 41 is located at the outermost side of the overall moisture-proof pressure relief structure, is bonded to the umbrella-shaped support structure 431 of the support structure 43 to form a cavity structure, and the moisture-proof diaphragm 42 is arranged in the cavity structure.

[0014] Further, the support structure 43 comprises an umbrella-shaped support structure 431, a spring mechanism 432, a support base 433, a mounting structure 434, and a sealing ring mounting structure 435; the umbrella-shaped support structure 431 is fixed in the mounting hole of the support base 433, the umbrella-shaped support structure 431 is sleeved with the spring mechanism 432 at the inner end of the mounting hole, the support base 433 is provided with the mounting structure 434 at both ends, which is used for screwing with the moisture-proof pressure relief structure 4, and the end portion of the moisture-proof pressure relief structure 4 that is screwed is provided with the sealing ring mounting structure 435, which is used for mounting the sealing ring 44.

[0015] Further, the breaking pressure of the upper cover 41 is 4Kpa±1Kpa, the thickness is 1-2mm, and the material is preferably PC, PC+ABS, PBT+20%GF or PA66; the breaking pressure of the moisture-proof film 42 is 4Kpa±1Kpa, the thickness is 0.5-2mm, it can adsorb water vapor molecules in the air, and the material is silica gel; the sealing ring 44 is in the shape of a circular sealing ring or a square sealing ring, the cross section is a long circle, the short circle length is 2mm±0.5mm, the long circle length is 3.5±0.5mm, and the material is rubber.

[0016] In a second aspect, the application provides a design method of a power battery upper box, specifically comprising the following steps:

[0017] Step one: taking the boundary, bearing, air tightness, heat preservation, fire prevention, and thermal runaway pressure relief rate of the battery pack upper box as design inputs;

[0018] Step two: confirming the basic thickness of the upper box body 1 and the thickness of the strength reinforcing coating 2 according to the bearing requirement;

[0019] Step three: confirming the thickness of the fireproof and heat preservation coating 3 according to the heat preservation and fire prevention requirement;

[0020] Step four: determining the number of moisture-proof and pressure relief structures according to the input of the thermal runaway pressure relief rate and the pressure relief capacity of the moisture-proof and explosion-proof structure 4;

[0021] Step five: determining the depth, bottom width, and opening width of the gas sealing structure 13 in the air tightness sealing structure, and the overall height of the cured sealing glue, and the interval distance of the anti-loose bolts according to the air tightness requirement;

[0022] Step six: performing structure, fluid, and thermal coupling simulation analysis;

[0023] Step seven: adjusting the direction and width of the strength reinforcing coating 15 on the upper box, adjusting the overall thickness of the fireproof and heat preservation coating 3, and adjusting the arrangement position of the monitoring system 5 according to the simulation results;

[0024] Step eight: repeating step six, if the design requirement is met, proceeding to step eight, if the design requirement is not met, repeating step seven;

[0025] Step nine: interconnecting the monitoring system 5 and the vehicle end, so that the passenger can monitor the power battery state in real time through the instrument panel.

[0026] Compared with the prior art, the application has the following advantages:

[0027] The application discloses a power battery upper box and a design method, which has multiple functions of bearing, sealing, fire prevention, heat preservation, temperature monitoring, torque attenuation monitoring and moisture resistance, realizes real-time monitoring and real-time early warning, meets the heat preservation requirement of the power battery, and inhibits the spread of fire when the power battery is in thermal runaway, wherein the moisture resistance and pressure relief structure has the function of blocking water vapor to maintain the dryness of the internal environment of the power battery; the monitoring system in the upper box is interconnected with the vehicle control end, and is used for monitoring and early warning the temperature change in the power battery; and the sealing flange surface bolts of the upper and lower boxes are monitored for torque attenuation. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the description of the embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual proportion.

[0029] Figure 1 It is a structural schematic diagram of a power battery upper box of the present application;

[0030] Figure 2 It is a structural schematic diagram of the upper box body of the power battery upper box of the present application;

[0031] Figure 3 It is a structural schematic diagram of the fireproof and heat preservation coating of the power battery upper box of the present application;

[0032] Figure 4 It is a structural schematic diagram of the moisture resistance and pressure relief structure of the power battery upper box of the present application;

[0033] In the drawings: upper box body 1, structural reinforcement coating 2, fireproof and heat preservation coating 3, moisture resistance and pressure relief structure 4, monitoring system 5;

[0034] Moisture resistance structure mounting surface 11, sealing surface lower edge reinforcement feature 12, gas sealing structure 13, strength reinforcement coating 15, monitoring system mounting surface 16;

[0035] First heat preservation coating 31, second heat preservation coating 32, fireproof coating 33;

[0036] Upper cover 41, moisture resistance diaphragm 42, support structure 43, sealing ring 44;

[0037] Umbrella-shaped support structure 431, spring mechanism 432, support base 433, mounting structure 434, sealing ring mounting structure 435. DETAILED DESCRIPTION

[0038] In order to clearly and completely describe the technical solutions of the present application and the specific working process thereof, in combination with the drawings of the specification, the specific embodiments of the present application are as follows:

[0039] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0040] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0041] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0042] Example 1

[0043] like Figure 1 As shown, this embodiment provides a power battery upper casing, including an upper casing body 1, a structural reinforcement coating 2, a fireproof and heat-insulating coating 3, a moisture-blocking and pressure-relief structure 4, and a monitoring system 5; the structural reinforcement coating 2 is bonded to the outside of the upper casing body 1, the fireproof and heat-insulating coating 3 is bonded to the inside of the upper casing body 1, the moisture-blocking and pressure-relief structure 4 is screwed onto the moisture-blocking structure mounting surface 11 on the upper casing body 1, and the monitoring system 5 is placed on the monitoring system mounting surface 15 of the upper casing body 1.

[0044] like Figure 2As shown, in the present embodiment, the upper surface of the upper box body 1 is provided with a moisture-proof structure mounting surface 11, a sealing surface lower edge reinforcing feature 12, a gas sealing structure 13, sealing glue, a strength reinforcing coating 15, and a monitoring system mounting surface 16; the moisture-proof structure mounting surface 11 is used for mounting the moisture-proof pressure relief structure 4, the sealing flange surface edge of the upper box body 1 is provided with a sealing surface lower edge reinforcing structure 12 for improving the sealing edge strength and reducing the installation deformation; the gas sealing structure 13 is located inside the sealing flange surface edge of the upper box body 1 and is used for limiting the shape of the sealing glue to form a regular-shaped sealing glue layer; the sealing glue is located inside the gas sealing structure 13; the structural strength reinforcing coating 15 is located outside the upper box body 1 and is used for pasting the structural reinforcing coating 2; the monitoring system mounting surface 16 is located inside the upper box body 1 and is used for mounting temperature sensors and pressure sensors; the monitoring system mounting surface 16 for mounting temperature sensors is located at the corresponding positions of the highest and lowest points of the overall package temperature, and the monitoring system mounting surface 16 for mounting pressure sensors is located at the position of the obvious torque attenuation area of the overall package; the sealing flange is connected with the lower box by bolts to form the internal space of the power battery.

[0045] In the present embodiment, the moisture-proof structure mounting surface 11 is located at the weakest position of the structural strength of the upper box body 1 and is composed of a boss mounting plane and a sealing ring groove; the sealing surface lower edge reinforcing 12 is a structural strength reinforcing edge stamped or bent in the -Z direction at the edge of the sealing flange surface, and the length of the edge is ≥1mm; the gas sealing structure 13 is located inside the sealing flange surface edge of the upper box body 1 by 8mm-15mm and is a trapezoidal groove sealing structure with a trapezoidal short side length ≥3mm, an opening width ≥8mm, and a depth ≥3mm; the bonding strength of the sealing glue and the gas sealing structure 13 is greater than the self-strength of the sealing glue, and the height after curing is ≥5mm; the strength reinforcing coating 13 has a depth of 2-5mm, a length of 100-1000mm, a width of 10-100mm, and a rectangular shape; the monitoring system mounting surface 16 is a square with a depth of 0.5-1.5mm and a side length of 2±1mm.

[0046] In the present embodiment, the structural strength reinforcing coating 2 is bonded to the outside of the upper box body 1 and includes a first reinforcing coating and a second reinforcing coating; the first reinforcing coating is bonded to the inside of the structural strength reinforcing coating 15 of the upper box body 1, and the second reinforcing coating is coated between the coating intervals of the first reinforcing coating 21; both the first reinforcing coating 21 and the second reinforcing coating 22 are used for reinforcing the structural strength of the upper box assembly and enhancing the load-bearing capacity of the upper box.

[0047] In this embodiment, the thickness of the first reinforcing coating is 1.5mm-3.0mm, the width is 15mm-40mm, the coating spacing is not less than 30mm, and its material is carbon fiber; the thickness of the second reinforcing coating is 1.0mm-2.5mm, the width is ≥30mm, and its material is diamond-like carbon (DLC) coating.

[0048] like Figure 3 As shown, in this embodiment, the fireproof and heat-insulating coating 3 is placed inside the upper box body 1. Its characteristics are: from top to bottom, it consists of a first heat-insulating coating 31, a second heat-insulating coating 32, and a fireproof coating 33; the first heat-insulating coating 31 is placed inside the upper box body 1, completely covering the inner side of the upper box body 1, with a thickness of 3mm-6mm, and its material is preferably polypropylene foam; the second heat-insulating coating 32 is placed inside the first heat-insulating coating 31, completely covering the inner side of the first heat-insulating coating 31, with a thickness of 4mm-6mm, and its material is preferably polyurethane foam; the fireproof coating 33 is placed inside the second heat-insulating coating 32, completely covering the inner side of the second heat-insulating coating 32, with a thickness of 1mm-3mm, and its material is preferably mica; the polypropylene foam 31 is an environmentally friendly material and has certain mechanical properties, which improves the load-bearing capacity of the upper box body 1. Polyurethane foam 32 is a non-recyclable material. Theoretically, its thermal conductivity is superior to that of polypropylene foam 31, balancing insulation performance and structural strength. The fire-retardant coating 33 is used to suppress the spread of fire and protect the internal insulation coating of the power battery in the event of overall thermal runaway or thermal propagation within the battery pack. A well-maintained insulation coating helps prevent heat transfer into the vehicle compartment and provides reaction time for the opening and pressure relief structure 4, offering valuable time for occupants to escape. Figure 3 As shown.

[0049] The moisture-blocking and pressure-relief structure 4 includes an upper cover 41, a moisture-blocking diaphragm 42, a support structure 43, and a sealing ring 44. The upper cover 41 is located on the outermost side of the overall moisture-blocking and pressure-relief structure and is bonded to the umbrella-shaped support structure 431 of the support structure 43 to form a cavity structure. The moisture-blocking diaphragm 42 is placed inside the cavity structure. The number of pressure-relief and moisture-blocking structures can be ≥1 depending on the actual usage and the amount of gas generated by the internal battery cell under extreme operating conditions, so that the overall mechanism can work under a predetermined pressure.

[0050] like Figure 4As shown, in the present embodiment, the support structure 43 is composed of an umbrella-shaped support structure 431, a spring mechanism 432, a support base 433, a mounting structure 434, and a sealing ring mounting structure 435; the umbrella-shaped support structure 431 is fixed in the mounting hole of the support base 433, the umbrella-shaped support structure 431 is sleeved with the spring mechanism 432 at the end inside the mounting hole, the two ends of the support base 433 are provided with the mounting structure 434 for screwing with the moisture-proof pressure relief structure 4, and the end screwing with the moisture-proof pressure relief structure 4 is provided with the sealing ring mounting structure 435 for mounting the sealing ring 44.

[0051] The breaking pressure of the upper cover 41 is 4Kpa±1Kpa, the thickness is 1-2mm, and the material is preferably PC, PC+ABS, PBT+20%GF or PA66; the breaking pressure of the moisture-proof diaphragm 42 is 4Kpa±1Kpa, the thickness is 0.5-2mm, it can adsorb water vapor molecules in the air, and the material is silica gel; the sealing ring 44 is a circular sealing ring or a square sealing ring, the cross section is a long circle, the short circle length is 2mm±0.5mm, the long circle length is 3.5±0.5mm, and the material is rubber.

[0052] In the normal working state of the power battery, the support structure 43 is in a closed state, the moisture-proof diaphragm 42 blocks the water vapor from entering the internal cavity of the power battery under the premise of maintaining internal gas exchange, ensures the dry environment inside, and the accumulated water is gathered in the flow groove and discharged outside the battery pack. When the power battery is in a thermal runaway or thermal spread working condition, the internal cavity pressure increases, further breaking the moisture-proof diaphragm 42, the spring mechanism 432 ejects the umbrella-shaped support structure 431, the plastic material of the upper cover 41 cannot withstand the pressure and is broken, further releasing the pressure, the structure explosion-proof function is started, the internal pressure of the cavity is released, and explosion is avoided due to the excessive internal pressure of the cavity. Provide time guarantee for passengers to escape. For example Figure 4 As shown.

[0053] The monitoring system 5 includes a temperature monitoring unit and a pressure monitoring unit; the temperature monitoring unit is arranged at the highest point and the lowest point of the whole pack, monitors the maximum temperature difference of the whole pack, and is interconnected with the vehicle end control unit; when the temperature difference is ≥3℃, the vehicle end instrument panel fault light alarms, and when the temperature difference is ≥7℃, the vehicle end control is powered off; the temperature monitoring unit is arranged in the area where the torque of the whole pack decays obviously, monitors the torque of the flange surface bolt of the whole pack, and is interconnected with the vehicle end control unit; when the torque attenuation is ≥30%, the vehicle end instrument panel fault light alarms, and when the torque attenuation is ≥70%, the vehicle end control is powered off.

[0054] The upper box provided by the embodiment has the functions of bearing, heat preservation, fire prevention, pressure relief and state monitoring, can monitor the temperature change of the battery pack temperature, and the torque change of the sealing surface flange surface bolt. When the external environment temperature changes, the temperature inside the power battery is kept stable, and when extreme adverse conditions such as thermal runaway occur, the spread of fire can be effectively inhibited, and the internal pressure of the battery box is released at the same time.

[0055] Embodiment 2

[0056] The embodiment provides a design method of a power battery upper box, and specifically comprises the following steps:

[0057] Step one: taking the boundary, bearing, air tightness, heat preservation, fire prevention and thermal runaway pressure relief rate of the battery pack upper box as design input;

[0058] Step two: according to the bearing requirement, confirming the basic thickness of the upper box body 1 and the thickness of the strength reinforcing coating 2;

[0059] Step three: according to the heat preservation and fire prevention requirement, confirming the thickness of the fireproof and heat preservation coating 3;

[0060] Step four: according to the input of the thermal runaway pressure relief rate, combining the pressure relief capacity of the moisture-proof and explosion-proof structure 4, determining the number of moisture-proof and pressure relief structures;

[0061] Step five: according to the air tightness requirement, determining the depth, bottom width and opening width of the gas sealing structure 13 in the air tightness sealing structure, and simultaneously determining the overall height of the cured sealing glue and the interval distance of the anti-loosening bolts;

[0062] Step six: performing structure, fluid and thermal coupling simulation analysis;

[0063] Step seven: according to the simulation result, adjusting the direction and width of the upper strength reinforcing coating 15 of the upper box, adjusting the overall thickness of the fireproof and heat preservation coating 3, and adjusting the arrangement position of the monitoring system 5;

[0064] Step eight: repeating step six, if the design requirement is met, proceeding to step eight, if the design requirement is not met, repeating step seven;

[0065] Step nine: arranging the monitoring system 5 at the highest point and the lowest point of the whole pack, monitoring the maximum temperature difference of the whole pack, and interconnecting with the vehicle end control unit, when the temperature difference is greater than or equal to 3 DEG C, the vehicle end instrument panel fault light alarms, and when the temperature difference is greater than or equal to 7 DEG C, the vehicle end control is powered off. Arranging the monitoring system 5 in the area where the torque attenuation of the whole pack is obvious, monitoring the torque of the flange surface bolt of the whole pack, and interconnecting with the vehicle end control unit, when the torque attenuation is greater than or equal to 30%, the vehicle end instrument panel fault light alarms, and when the torque attenuation is greater than or equal to 70%, the vehicle end control is powered off. The monitoring system 5 is interconnected with the vehicle end, so that the passenger can monitor the state of the power battery in real time through the instrument panel.

[0066] Embodiment 3

[0067] The embodiment provides an electric vehicle, comprising a vehicle body and the power battery upper box body.

[0068] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0069] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0070] In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, and it should be considered as disclosed by the present application.

Claims

1. A power battery upper casing, characterized in that, The system includes an upper housing body (1), a structural reinforcement coating (2), a fireproof and heat-insulating coating (3), a moisture-proof and pressure-relief structure (4), and a monitoring system (5). The structural reinforcement coating (2) is bonded to the outside of the upper housing body (1), the fireproof and heat-insulating coating (3) is bonded to the inside of the upper housing body (1), the moisture-proof and pressure-relief structure (4) is screwed onto the moisture-proof structure mounting surface (11) on the upper housing body (1), and the monitoring system (5) is placed on the monitoring system mounting surface (16) of the upper housing body (1). The upper surface of the upper housing body (1) is provided with a moisture-proof structure mounting surface (11), a sealing surface under-flanged reinforcement structure (12), a gas sealing structure (13), sealant, a strength-enhancing coating (15), and a monitoring system mounting surface (16). The moisture-proof structure mounting surface (11) is used for the installation of the moisture-proof pressure relief structure (4). The sealing flange edge of the upper housing body (1) is provided with a sealing surface under-flanged reinforcement structure (12) to improve the sealing edge strength and reduce installation deformation. The gas sealing structure (13) is located inside the sealing flange edge of the upper housing body (1) to limit the shape of the sealant and form a shape regulation. The sealing layer is located inside the gas sealing structure (13); the strength-enhancing coating (15) is located on the outside of the upper housing body (1) and is used to attach the structural reinforcement coating (2); the monitoring system mounting surface (16) is located on the inside of the upper housing body (1) and is used to install temperature sensors and pressure sensors; the monitoring system mounting surface (16) for installing temperature sensors is located at the corresponding positions of the highest and lowest temperatures of the entire package, and the monitoring system mounting surface (16) for installing pressure sensors is located in the area where the torque attenuation of the entire package is obvious; the sealing flange is connected to the lower housing body by bolts to form the internal space of the power battery.

2. The upper casing of a power battery as described in claim 1, characterized in that, The moisture-proof structure mounting surface (11) is located at a weak point in the structural strength of the upper housing body (1), and is composed of a boss mounting plane and a sealing ring groove; the flange length of the sealing surface under-flanged reinforcement structure (12) is ≥1mm; the gas sealing structure (13) is located 8mm-15mm inside the edge of the sealing flange surface of the upper housing body (1), and is a trapezoidal groove sealing structure with a trapezoidal short side length ≥3mm, an opening width ≥8mm, and a depth ≥3mm; the strength-enhancing coating (15) has a depth of 2-5mm, a length of 100-1000mm, a width of 10-100mm, and a rectangular shape; the monitoring system mounting surface (16) is a square with a depth of 0.5-1.5mm and a side length of 2±1mm.

3. The upper casing of a power battery as described in claim 1, characterized in that, The structural reinforcement coating (2) is bonded to the outside of the upper box body (1) and includes a first reinforcement coating and a second reinforcement coating. The first reinforcement coating is bonded to the inside of the strength reinforcement coating (15) of the upper box body (1), and the second reinforcement coating is applied between the coating intervals of the first reinforcement coating (21). Both the first reinforcement coating (21) and the second reinforcement coating (22) are used to strengthen the structural strength of the upper box assembly and enhance the load-bearing capacity of the upper box.

4. The upper casing of a power battery as described in claim 3, characterized in that, The first reinforcing coating has a thickness of 1.5mm-3.0mm, a width of 15mm-40mm, and a coating spacing of not less than 30mm. Its material is carbon fiber. The second reinforcing coating has a thickness of 1.0mm-2.5mm, a width of ≥30mm, and its material is diamond-like carbon (DLC) coating.

5. The upper casing of a power battery as described in claim 1, characterized in that, The fireproof and heat-insulating coating (3) is placed inside the upper box body (1) and consists of a first heat-insulating coating (31), a second heat-insulating coating (32) and a fireproof coating (33) from top to bottom. The first heat-insulating coating (31) completely covers the inner surface of the upper box body (1) with a thickness of 3mm-6mm and is made of polypropylene foam. The second heat-insulating coating (32) completely covers the inner surface of the first heat-insulating coating (31) with a thickness of 4mm-6mm and is made of polyurethane foam. The fireproof coating (33) completely covers the inner surface of the second heat-insulating coating (32) with a thickness of 1mm-3mm and is made of mica.

6. The upper casing of a power battery as described in claim 1, characterized in that, The moisture-proof and pressure-relief structure (4) includes an upper cover (41), a moisture-proof membrane (42), a support structure (43), and a sealing ring (44); the upper cover (41) is located on the outermost side of the overall moisture-proof and pressure-relief structure, and is bonded to the umbrella-shaped support structure (431) of the support structure (43) to form a cavity structure, and the moisture-proof membrane (42) is placed inside the cavity structure.

7. The upper casing of a power battery as described in claim 6, characterized in that, The support structure (43) consists of an umbrella-shaped support structure (431), a spring mechanism (432), a support base (433), an installation structure (434), and a sealing ring installation structure (435). The umbrella-shaped support structure (431) is fixed in the installation hole of the support base (433). The spring mechanism (432) is fitted at the end of the umbrella-shaped support structure (431) located in the installation hole. The support base (433) is provided with installation structures (434) at both ends for screwing with the moisture-proof and pressure-relief structure (4). The end screwed with the moisture-proof and pressure-relief structure (4) is provided with a sealing ring installation structure (435) for installing the sealing ring (44).

8. The upper casing of a power battery as described in claim 6, characterized in that, The upper cover (41) has a breaking pressure of 4Kpa±1Kpa, a thickness of 1-2mm, and is made of PC, PC+ABS, PBT+20%GF or PA66; the moisture barrier membrane (42) has a breaking pressure of 4Kpa±1Kpa, a thickness of 0.5-2mm, and can adsorb water vapor molecules in the air, and is made of silicone; the sealing ring (44) is a circular sealing ring or a square sealing ring, with an oblong cross-section, a short circle length of 2mm±0.5mm, an oblong length of 3.5±0.5mm, and is made of rubber.

9. The design method of the upper casing of a power battery as described in claim 1, characterized in that, Specifically, the steps include the following: Step 1: Use the boundaries, load-bearing capacity, airtightness, thermal insulation, fire resistance, and thermal runaway pressure relief rate of the battery pack enclosure as design inputs; Step 2: Based on the load-bearing requirements, confirm the foundation thickness of the upper box body (1) and the thickness of the structural reinforcement coating (2); Step 3: Determine the thickness of the fireproof and heat-insulating coating (3) according to the heat preservation and fireproof requirements; Step 4: Based on the input of the thermal runaway pressure relief rate and the pressure relief capacity of the moisture-proof pressure relief structure (4), determine the number of moisture-proof pressure relief structures; Step 5: Based on the airtightness requirements, determine the depth, bottom width, and opening width of the gas sealing structure (13) in the airtight sealing structure, and at the same time determine the overall height after the sealant has cured and the spacing of the anti-loosening bolts. Step Six: Perform structural, fluid, and thermal coupling simulation analysis; Step 7: Adjust the direction and width of the strength-enhancing coating (15) on the upper box body according to the simulation results, adjust the overall thickness of the fireproof and heat-insulating coating (3), and adjust the layout of the monitoring system (5); Step 8: Repeat step 6. If the design requirements are met, proceed to step 9. If the design requirements are not met, repeat step 7. Step 9: Connect the monitoring system (5) to the vehicle so that passengers can monitor the status of the power battery in real time through the instrument panel.

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