How to install a battery pack in a vehicle

Abstract

A method for mounting a battery pack to the body of a passenger car is provided. The method includes the step of providing a vehicle frame that defines at least the floor portion of the vehicle body. A battery pack is provided and the battery pack is placed within the floor portion of the vehicle body. The battery pack is then bonded to the frame using at least one adhesive joint located at the interface between the battery pack and the frame.

Description

Technical Field

[0001] The present invention relates to a method of mounting a battery pack on a passenger vehicle body. In particular, the present invention relates to a method of mounting a traction battery (used to supply power to an electric motor) on the body of an electric passenger vehicle or a hybrid passenger vehicle.

Background Art

[0002] In electric and hybrid passenger vehicles, it is necessary to integrate a relatively large-sized battery pack into the vehicle body. The manner of integrating the battery pack affects the structure, safety, comfort, and operating performance of the vehicle. The battery pack is usually manufactured separately from the vehicle frame and then mounted on the vehicle frame. Prior art methods for joining the battery pack to the vehicle body are based on mechanical fasteners to provide for the repairability of the battery pack. That is, the battery pack is generally attached to the frame by mechanical fasteners (e.g., bolts, etc.), and the mechanical fasteners can be quickly and easily engaged and disengaged to mount the battery during manufacture and, subsequently, to remove the battery, for example, for repair.

[0003] One of the most significant differences between electric or hybrid passenger vehicles and internal combustion engine vehicles is the need to maintain the safety of both the occupants and the battery by avoiding pack intrusion during a crash. This is generally achieved in part by transmitting crash loads around the battery pack with respect to frontal and rear crashes. One of the greatest design challenges is to ensure that the battery pack is protected during a side impact crash or collision. This is particularly difficult because there is limited space in the rocker or sill for a crumple zone required to absorb side impact crash loads without damaging the battery pack.

[0004] Mechanical fasteners for mounting battery packs to the vehicle body are typically oriented to a substantially vertical axis for ease of access during manufacturing and repair. This joint orientation also allows the interface between the battery pack and the vehicle body to be positioned above a substantially horizontal and planar interface, avoiding the risk of accumulating manufacturing tolerances that would create undesirable gaps between adjacent components (in this case, the battery pack and the vehicle body). Furthermore, this joint orientation accommodates a substantially vertical orientation for the installation and removal of heavy battery packs. However, mechanical fasteners used to enable a vertical mounting orientation are typically inefficient in transmitting or responding to loads applied perpendicular to their main axis (i.e., shear loads). Therefore, to ensure the battery pack remains secure during impact, the number and size of fasteners must be increased to prevent all possible failure modes, including bolt shear failure, joint slip failure, and failure at the edges of bolt holes. Of particular importance is the shear load generated inside the vehicle from a side crash (especially a side pole crash). Strengthening mechanical fasteners to prevent all possible failure modes can lead to a significant increase in the vehicle's weight. This is particularly disadvantageous in the context of electric vehicles, where weight reduction is a critical consideration, and in particular, reaching the target range is a mandatory design consideration, the solution of which often involves adding more batteries and consequently adding more weight. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] European Patent Application Publication No. 4011668 [Patent Document 2] U.S. Patent Application Publication No. 2023 / 026490 [Patent Document 3] China Utility Model No. 214280109 [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, it is desirable to provide an alternative method for mounting a battery pack inside a vehicle body that overcomes the aforementioned drawbacks associated with mechanical fasteners. [Means for solving the problem]

[0007] According to a first aspect of the present invention, a method is provided for mounting a battery pack to the body of a passenger car, the method comprising the steps of: providing a vehicle frame defining at least the floor portion of the vehicle body; providing a battery pack; positioning the battery pack on the floor portion of the vehicle body; and joining the battery pack to the frame using at least one adhesive joint located at the interface between the battery pack and the frame.

[0008] According to the present invention, the battery pack is mounted on the vehicle frame and at least partially secured using one or more adhesive joints at the interface between the battery pack and the frame. When used as a substitute for or in combination with mechanical fasteners, adhesive joints allow for substantially lighter designs. This is because adhesive joints generally have a superior ability to transmit or respond to shear loads compared to mechanical fasteners.

[0009] It should be noted that this technique is intended for use when installing a main vehicle battery pack (sometimes referred to as a traction battery) used to power the electric motors of a vehicle. Therefore, this method may further include connecting the battery pack to one or more electric motors of a passenger car.

[0010] The vehicle frame generally corresponds to the so-called body-in-white (BIW), where the frame defines at least the cabin of the passenger car. However, the frame can also be a component that will later be assembled into the body or BIW. For example, the frame can include a floor frame, which can define the rocker and / or door sill portions of the body, and it generally defines the floor plane of the vehicle. Thus, the battery pack can be mounted within this floor frame before the floor frame is joined to one or more other frame portions that define the body or BIW.

[0011] This method may be suitable for mounting any type of battery pack to a vehicle body. This includes batteries based on different battery chemistry, as well as different battery cell and module architectures. Generally, a battery pack will consist of one or more battery modules arranged within a housing, and the battery pack will be mounted to the vehicle body by coupling the battery pack housing to the frame.

[0012] Preferably, the battery pack includes a housing formed from a fiber-reinforced composite material, which preferably includes a resin matrix, reinforcing fibers, and metal inserts. However, other battery pack housings, such as a metal housing made from an aluminum alloy, may also be used. The vehicle frame can be made from metal, for example, an aluminum alloy assembly. Alternatively, the frame can be formed from a fiber-reinforced composite material, which, again, may include a resin matrix, reinforcing fibers, and metal inserts.

[0013] Preferably, the adhesive joint is formed by a paste-like adhesive applied to either the battery pack or the vehicle frame, or both, before the battery pack and the vehicle frame are joined together. In some cases, it may be advantageous to use a liquid adhesive, in which case the adhesive can be injected into the gap between the battery and the vehicle frame after the battery and the vehicle frame have been joined or otherwise positioned in place. Preferably, when cured, the adhesive can withstand all major external loads that the joint will be subjected to during the lifecycle of the vehicle and battery pack. Therefore, the adhesive is preferably a structural adhesive that can generate sufficiently high strength in the joint (e.g., greater than 5 MPa, preferably greater than 10 MPa, and more preferably greater than 25 MPa). Preferably, the adhesive is tough and therefore well suited to maintaining the integrity of the joint when subjected to impact loads. For example, the fracture toughness of the structural adhesive can be greater than 0.1 N / mm, preferably greater than 1 N / mm, and more preferably greater than 10 N / mm.

[0014] Preferably, the adhesive exhibits thixotropic behavior, facilitating its application to either the battery or the vehicle frame, either manually or through an automated delivery system.

[0015] Preferably, the adhesive viscosity is moderate to limit the load required to connect the battery pack to the vehicle frame due to hydraulic lock resulting from the adhesive flow.

[0016] The adhesive is preferably applied to the battery pack when the battery pack is detached from the vehicle frame and when the adhesive application surface is mainly horizontal and facing upward. The adhesive is preferably able to fill gaps and thus compensate for any small geometric variations between the vehicle frame and the battery pack resulting from manufacturing and assembly tolerances.

[0017] The adhesive chemistry is preferably selected from a wide range of commercially available grades for structural adhesives (preferably polyurethane, epoxy, or acrylic, etc.).

[0018] The adhesive is preferably a different color (e.g., a light color) from the color of the vehicle frame and battery pack in order to provide visual confirmation of its presence for inspection purposes.

[0019] Preferably, the adhesive exhibits fire resistance in accordance with international requirements for battery systems in passenger cars (e.g., ECER100).

[0020] In some embodiments, the adhesive can be conductive. For example, the adhesive can contain conductive additives (e.g., graphene). Conductive adhesives may be useful for electrically connecting a battery pack to a frame for a ground circuit.

[0021] Typically, the adhesive used to form the bonded joint is pre-coated onto the battery pack or frame before the battery pack is placed in the vehicle's floor area. In particular, the adhesive can be coated onto a portion of the frame or battery pack that will subsequently form part of the interface. Once the battery pack is in place, the frame and battery pack can be pressed together with the adhesive bonding them together.

[0022] Another advantage of adhesive joints is that, due to the adhesive's ability to fill gaps in the joined surfaces, it is possible to improve manufacturing tolerances. The thickness of the adhesive layer may need to be adjusted to adequately accommodate such surface variations resulting from manufacturing tolerances. It has been found that the thickness of each adhesive joint should be at least 0.5 mm, preferably at least 1 mm, more preferably at least 2 mm, and most preferably at least 3 mm. Also, thicker adhesive joints will allow the battery pack to be removed more easily during repairs, as will be described below. Thus, the adhesive can be coated onto the battery pack or frame with a thickness of at least 0.5 mm, preferably at least 1 mm, more preferably at least 2 mm, and most preferably at least 3 mm. The adhesive will typically be pressed during the bonding process, and therefore the coating thickness of the adhesive may need to be thicker than the desired final adhesive joint thickness. The coating thickness required to achieve a particular joint thickness will depend, among other factors, on the specific adhesive used, the parameters of its application, and the pressure applied during the bonding process.

[0023] The adhesive can be provided anywhere the battery pack interfaces with the frame, but preferably, one or more adhesive joints are disposed along the periphery of the battery pack. The periphery is generally considered to be the region of the battery pack near its edges, in a direction perpendicular to the plane defined by the floor portion, relative to the central axis of the battery pack in the direction of this plane. Generally, the frame defining the floor portion of the vehicle body will have a substantially rectangular footprint, which defines opposing longitudinal edges facing the floor (corresponding to the opposing sides of the vehicle body), and, optionally, a front edge and a rear edge corresponding to the front and rear of the vehicle respectively. Generally, the plane defined by the floor portion can correspond to the plane between these opposing longitudinal edges and, if provided, between the front and rear edges of the frame. Also, typically, the battery pack will generally define a plane having a height smaller than its length and width, will seat substantially aligned with the plane of the floor portion, and can have a substantially rectangular footprint. The battery pack will typically extend across the floor portion between the opposing longitudinal edges defined by the frame. The battery pack can have opposing longitudinal edges that extend along the opposing longitudinal edges of the floor portion defined by the frame. Providing adhesive joints along the periphery of the battery pack is suitable. This is because this is generally where the frame defining the floor and the battery will interface, and because this is generally more accessible during manufacturing and repair. The adhesive joints will typically be elongated and define a path extending along the periphery.

[0024] The adhesive joints can be positioned along any one or more peripheral edges of the battery pack, but preferably, one or more adhesive joints are positioned along at least two opposing peripheral edges of the battery pack. This improves the strength of the bond to the battery pack. For example, the adhesive joints can be provided along peripheral edges adjacent to opposing longitudinal edges of the floor portion defined by the frame. In a particularly preferred embodiment, one or more adhesive joints substantially surround the central region of the battery pack. For example, one or more adhesive joints can extend along opposing longitudinal edge portions of the battery pack, as well as along the front and rear edge portions of the battery pack. In this case, there can be one long, continuous adhesive joint extending along all four edge portions, or there can be multiple separate adhesive joints extending along these edge portions. Providing adhesive along a larger proportion of the edges of the battery pack improves the strength of the bond to the frame.

[0025] There are a variety of possible ways in which the interface between the battery pack and the frame can be designed. In a simple case, the battery pack can have a flat upper or lower surface and can be seated against the flat floor surface provided by the frame. However, the interface can be designed to provide further advantages in the mounting method. In particular, in some embodiments, the battery pack includes one or more peripheral flanges configured to form at least a portion of the interface with the frame, and one or more adhesive joints are disposed along one or more of the peripheral flanges. It will be recognized that other adhesive joints can also be provided in areas remote from the peripheral flanges. Also, the frame can be provided with one or more complementary rim portions configured to engage the peripheral flange portion of the battery pack. Providing a peripheral flange of the battery pack (on which the adhesive joint will be provided) can provide a number of advantages, including ensuring that the adhesive joint is spaced from the battery cells of the battery pack, which is advantageous during repair. Moreover, the use of a peripheral flange with complementary rims can help seat the battery pack on the frame.

[0026] Another advantageous way the interface may be configured is that the interface between the battery pack and the frame includes one or more portions that substantially define a stepped interface. Preferably, at least one adhesive joint is positioned on one or more at least two different surfaces of the portion that substantially defines the stepped interface. Again, this can be provided by a single adhesive joint extending across both surfaces, or by separate adhesive joints. The stepped interface can define surface portions at two different height levels (generally perpendicular to the plane defined by the floor) along which the adhesive joint can be positioned. Alternatively, the stepped interface can allow the adhesive joint to be provided along surfaces that are at different angles to each other (e.g., substantially perpendicular to each other), so that the joint experiences impact forces in different relative directions. Furthermore, the stepped interface can again assist in seating the battery pack to the frame before bonding with the adhesive joint.

[0027] As described above, the floor portion of a vehicle generally defines a plane, and the battery pack generally defines a plane that is substantially aligned with or at least parallel to the plane of the floor. However, it may be preferable that the interface between the battery pack and the frame includes one or more portions positioned at a predetermined angle (preferably an oblique angle) with respect to the plane defined by the floor portion, and at least one adhesive joint is positioned on the one or more portions of the interface positioned at a predetermined angle with respect to the plane defined by the floor portion. Particularly preferably, the interface between the battery pack and the frame includes one or more portions that define an angle of less than 45°, more preferably less than 30°, with respect to the plane defined by the floor portion, most preferably less than 20°. This may involve, for example, the peripheral flange portion of the battery pack defining an oblique angle with respect to the general plane of the battery pack, and a portion of the frame being provided with a complementary angle for engaging with the peripheral flange portion. Providing interface portions that are neither parallel nor perpendicular to the plane generally defined by the floor portion of the frame can help the adhesive joint handle impact forces. In particular, impact forces along the direction in the plane of the floor can therefore partially place the adhesive joint in a compressional rather than purely shearing state. For the most advantageous handling of impact forces, one or more inclined portions of the interface between the battery pack and the frame should be positioned at an angle that is generally inclined toward or away from the center of the battery pack.For example, an inclined portion lying along the longitudinal edge of the battery pack should be inclined about a longitudinal axis in the plane of the floor, while an inclined portion lying along the front or rear edge of the battery pack should be inclined about a transverse axis in the plane of the floor, with the longitudinal edge advantageously handling lateral impact forces, and the front and rear edges advantageously handling front and rear impact forces.

[0028] In some embodiments of this method, the frame defines an opening through the frame in the floor portion, and the battery pack closes the opening, thereby defining at least an area of ​​the vehicle's floor. In other words, the battery pack itself acts as a substantial section of the vehicle's floor surface.

[0029] In other embodiments, the frame can define a substantially continuous floor surface in the floor portion of the vehicle body, and the battery pack is positioned substantially adjacent to the floor surface, for example, with the plane of the battery pack parallel to the plane of the floor surface. In such embodiments, the floor surface of the vehicle body is provided by the frame, which allows for the removal and replacement of the battery pack during repairs.

[0030] The frame defining the floor portion may include, for example, longitudinal structural members (e.g., rocker or door sill portions of the frame, or center tunnel structures, etc.) and generally comprises one or more transverse structural members corresponding to the front and rear edges of the floor portion. If provided, an opening through the frame may substantially extend between the longitudinal and transverse structural members. Thus, a battery pack may substantially fill this opening through the frame and be bonded to the longitudinal and / or transverse structural members by adhesive joints. Such an arrangement may make the vehicle body lighter. In other embodiments, a substantially continuous floor may extend between the longitudinal and transverse structural members, and the battery pack may be bonded to the longitudinal and / or transverse structural members, and / or to the floor surface of the frame, by adhesive joints.

[0031] This method utilizes adhesive bonding to overcome several drawbacks associated with mechanical fasteners, but in many embodiments, it may be preferable to use both mounting means to benefit from the advantages each offers. Therefore, in some embodiments, the method further includes the step of securing the battery pack to the frame using one or more mechanical fasteners. The mechanical fasteners can be positioned at the interface between the battery pack and the frame. In particularly preferred embodiments, the mechanical fasteners can be used to position and hold the battery pack in place relative to the frame for subsequent bonding using adhesive bonding. Therefore, preferably, the step of positioning the battery pack in the floor portion of the vehicle body includes engaging one or more mechanical fasteners positioned at the interface between the battery pack and the frame to guide and / or hold the battery pack in place on the frame. Alternatively, the guiding effect can be achieved by guiding members (e.g., dowel pins and corresponding openings) provided on the battery pack and frame. Mechanical fasteners are preferred for their contribution to holding the battery pack in place in case of adhesive failure and during the curing of the adhesive. In particular, preferably, the step of joining the battery pack to the frame includes clamping the battery pack to the frame using one or more mechanical fasteners while the adhesive cures. While it is preferable that the mechanical fasteners are used to bias the frame and the battery pack together, it may be desirable to ensure a certain gap between the battery pack and the frame, for example, to prevent too much adhesive from being squeezed out of the joint or to ensure that the battery pack is horizontal within the frame. Therefore, preferably, one or more mechanical fasteners include one or more spacing elements configured to prevent direct contact between the battery pack and the frame, and the one or more spacing elements are preferably configured to ensure a predetermined minimum gap between the battery pack and the frame.

[0032] The frame may include longitudinal and transverse structural members, and as described above, the battery pack is coupled to these structural members. More generally, the frame may include opposing structural members, and the method includes the steps of positioning the battery pack between the opposing structural members and joining the battery pack to each of the opposing structural members, preferably the step of joining the battery pack to one or more of the opposing structural members includes joining the battery pack to the structural member using an adhesive joint located at the interface between the battery pack and the structural member. In this way, the battery pack can form a load path between the opposing structural members, and impact forces can be transmitted between the opposing structural members by the battery pack. Preferably, the battery pack can be coupled to each of two sets of opposing structural members in this manner, preferably to two sets of vertical opposing structural members, for example, a pair of longitudinal structural members (e.g., door sill portions) and transverse structural members (e.g., front structural members and rear structural members). In a particularly preferred embodiment, the interface between the battery pack and the frame includes one or more portions positioned at a predetermined angle to a plane defined by the floor portion, and at least one adhesive joint is located on the one or more portions of the interface positioned at a predetermined angle to a plane defined by the floor portion, wherein the opposing structural members define one or more portions positioned at a predetermined angle to a plane defined by the floor portion, preferably each opposing structural member defines a portion positioned at a predetermined angle to a plane defined by the floor portion, and at least one adhesive joint is located on each of the respective portions positioned at a predetermined angle to a plane defined by the floor portion.In other embodiments, the interface with an opposing structural member can define a substantially stepped interface, and at least one adhesive joint is located on one or more different surfaces of the portion defining the substantially stepped interface.

[0033] Alternatively or additionally, the frame can define at least a portion (e.g., partial or continuous) of the floor surface in the floor portion of the vehicle body and a structural member extending away from the floor surface, and the method includes the steps of joining a battery pack to a structural member and joining a battery pack to the floor surface of the frame, preferably the step of joining a battery pack to a structural member includes joining the battery pack to the structural member using an adhesive joint located at the interface between the battery pack and the structural member, and / or, preferably the step of joining a battery pack to the floor surface includes joining the battery pack to the floor surface using an adhesive joint located at the interface between the battery pack and the floor surface. In this way, the battery pack can define a portion of the load path for transmitting impact forces from the structural member into the floor surface of the frame.

[0034] In some embodiments, the frame may include opposing structural members and at least a portion of the floor surface of the vehicle body floor portion, and the method may include the steps of positioning a battery pack between the opposing structural members, joining the battery pack to each of the opposing structural members, and preferably joining the battery pack to the floor portion at each location adjacent to each of the opposing structural members, and preferably one or more (preferably each) joining steps are carried out by joining using adhesive joints located at the interface between the respective parts. In this way, loads can be transmitted between the opposing structural members and between the structural members and the floor surface, thereby more effectively shielding the contents of the battery pack from damage.

[0035] As described above, the frame may include opposing longitudinal structural members positioned along the opposing longitudinal edges of the floor portion of the vehicle body. These structural members are particularly useful in shielding the battery pack from impact forces, and therefore, preferably, the step of positioning the battery pack on the floor portion of the vehicle body includes the step of positioning the battery pack substantially between the opposing longitudinal structural members. That is, the battery pack may be positioned substantially within a plane defined between the opposing longitudinal structural members.

[0036] In some embodiments, the steps of positioning the battery pack on the floor portion of the vehicle body and joining the battery pack to the frame include positioning the battery pack to the frame such that the weight of the frame acts to press against the battery pack during joining. This method is particularly useful in combination with guide elements to ensure proper in-plane relative positioning of the battery pack and the frame. As described above, the guide elements can be provided by mechanical fasteners or separate elements (e.g., dowel pins). This technique is particularly preferred over the jig-setting technique because it allows the method to be implemented using readily available lift-type equipment, and eliminates the need for expensive, model-specific jigs.

[0037] The adhesive joint should be located on a relatively rigid part of the battery pack so as to contribute to holding the battery pack in place on the frame, and so as to allow the crash load to be transmitted across the joint and then directed by the battery pack in a manner that shields the contents of the battery pack from damage. Preferably, the material of the battery pack at the location of the adhesive joint has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, more preferably at least 20 GPa, and most preferably at least 50 GPa. Preferably, the adhesive joint is located on the fiber-reinforced composite surface of the battery pack. Preferably, the material of the frame at the location of the adhesive joint is also rigid and has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, more preferably at least 20 GPa, and most preferably at least 50 GPa. The frame will typically be aluminum or an aluminum alloy, which can have a Young's modulus of 70 or more.

[0038] One way a battery pack can shield its contents from impact forces is by transmitting the crash load across the battery pack and returning it to another section of the frame. Therefore, preferably, the battery pack includes a housing, and the material of the housing, extending between the adhesive joint and either another joint between the battery pack and the frame or another section of the same adhesive joint, has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, more preferably at least 20 GPa, and most preferably at least 50 GPa. In these embodiments, the rigid material of the battery pack housing can form part of the load path between two joints by providing rigid material between two separate joints to the frame, or between two different (e.g., opposing) sections of the same joint. One particularly preferred embodiment is one in which the battery pack is bonded to two opposing structural members of the frame, and the material of the housing extending between the opposing structural members has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, more preferably at least 20 GPa, and most preferably at least 50 GPa. Preferably, the battery pack includes a housing surrounding one or more internal battery modules, and substantially the entire housing has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, more preferably at least 20 GPa, and most preferably at least 50 GPa. Preferably, but in alternative embodiments, only a portion of the battery pack housing can be rigid while achieving the same effect.For example, the base and optionally the side walls of the battery pack can be rigid, and a less rigid lid may be provided, in which case the crash impact force can be transmitted across the battery pack by the rigid base.

[0039] One disadvantage of using adhesive joints as well as mechanical fasteners, or as an alternative to mechanical fasteners, is that adhesive bonds are generally permanent, while mechanical fasteners can be selectively engaged and disengaged to mount and remove the battery pack from the vehicle body. Therefore, when adhesive joints are used, it is desirable to facilitate the removal of the battery pack. Preferably, the step of joining the battery pack to the frame using at least one adhesive joint includes the step of providing a conduit across at least one of the adhesive joints, through which a wire can be inserted to cut at least one of the adhesive joints. The conduit can be a tube inserted between the battery pack and the frame before the application of the adhesive forming the adhesive joint. The conduit can be left open at both ends or can be closed to prevent material ingress. Nevertheless, the conduit can retain a hollow center after the formation of the adhesive joint, allowing for a convenient path, through which a wire can be passed for use when cutting the adhesive joint. As will be described in more detail below, once the wire is positioned through the conduit, it can be pulled through the adhesive joint, for example, by a technician holding the end of the wire on either side of the conduit to cut the joint. To allow the insertion of a suitable wire to cut the joint, the conduit preferably has a width of at least 0.5 mm, more preferably at least 1 mm, and most preferably at least 2 mm.

[0040] Preferably, to allow the wires to be properly positioned and operated when the battery pack is removed, the conduit is positioned such that a first end of the conduit is accessible from a first side of the adhesive joint and a second end of the conduit is accessible from a second side of the adhesive joint. For example, one end of the conduit should be positioned to be inaccessible, enclosed between the frame and the battery pack. If the frame is provided with an opening through it in the floor portion, accessibility to both ends of the conduit can be conveniently provided. In such a case, one side of the conduit may be accessible from outside the frame, and the other side may be accessible through the opening through the frame in the floor portion. Other means of providing access to both ends of the conduit are foreseen, including providing a conduit that extends across the entire width of the battery pack (optionally, across multiple adhesive joints).

[0041] In some embodiments, it may not be practical to provide a conduit across the adhesive joint, accessible from both sides, so that a technician can insert and operate a wire for cutting the joint. Therefore, some embodiments further include providing at least one wire for cutting at least one adhesive joint to a frame or battery pack, wherein the cutting wire is positioned and fixed in place, and a portion of the wire is accessible to pull the wire through at least one adhesive joint to cut at least one adhesive joint. For example, at least one end of the wire is capable of extending across the adhesive joint so that it is accessible to a technician for pulling through the adhesive joint. Some such embodiments include providing at least one wire for cutting at least one adhesive joint to a frame or battery pack, wherein a first end of the wire is anchored to the frame or battery pack, and the battery pack is positioned and bonded to the frame such that a portion of the wire is accessible to pull the wire through at least one adhesive joint to cut at least one adhesive joint.

[0042] There are several arrangements in which an integrated wire can be positioned for use when cutting an adhesive joint. The wire can lie along a path, for example, substantially following the path of at least one adhesive joint along the interface between the battery pack and the frame, and is optionally weakly bonded or otherwise removable to the frame or battery pack along its length, with a portion of the wire (e.g., a second end in the case where the first end is fixed to the battery pack or frame) positioned to be accessible to the technician. Thus, the technician can position the wire by the accessible end so that the wire extends across the adhesive joint, either through a conduit or at the end of the adhesive joint, and then pull the wire through the adhesive joint by one of the accessible ends. The fixed first end ensures that, in order to cut the joint, it is only necessary for the wire to be pulled by the technician from one side of the adhesive joint (the fixing point is typically located on the opposite side of the adhesive joint).

[0043] Some embodiments include the step of providing a conduit across at least one of the adhesive joints, wherein a first end of a wire is fixed to the frame or battery pack at a first side of the conduit, and the wire is positioned to pass through the conduit such that a portion of the wire is accessible from a second side of the conduit, or the wire is positioned such that a portion of the wire is accessible through the conduit from a second side of the conduit. In these embodiments, the conduit across the adhesive joint is used to position or make accessible an integral cutting wire in order to facilitate the cutting of the adhesive joint. In this case, the conduit may be provided by simply positioning a cutting wire across the location of the adhesive joint before the adhesive is applied, so that the cutting wire is embedded across the adhesive and defines a conduit through the adhesive joint. Alternatively, a separate tube of the type described above may be provided through which the wire extends across the adhesive joint.

[0044] As an alternative to securing one end of the wire to the battery pack or frame, the cut wire can be provided such that the opposing ends of the cut wire pass through the same or each conduit across at least one of the adhesive joints. Thus, a technician can pull both ends of the wire to cut it through the adhesive joint.

[0045] In the above embodiment, which includes an integral cutting wire for cutting an adhesive joint, it will be recognized that one or more integral cutting wires may be provided. One cutting wire may be used to cut multiple adhesive joints. Alternatively, separate joints may be provided with their own cutting wires. It may also be possible to provide multiple cutting wires for cutting different sections of a single adhesive joint.

[0046] Preferably, the method further includes the step of electrically and / or hydraulically connecting the battery pack and the frame to each other. For example, the battery pack can be connected to the frame by a conductor to provide a ground circuit, for example. For example, the ground circuit can be provided by one or more mechanical fasteners. Therefore, the mechanical fasteners should be formed from a conductive material.

[0047] A second aspect of the present invention provides a method for removing a battery pack mounted on the body of a passenger car, the passenger car comprising a vehicle frame defining at least the floor portion of the vehicle body, and a battery pack in the floor portion of the vehicle body, the battery pack being bonded to the frame by at least one adhesive joint located at the interface between the battery pack and the frame, the method comprising the step of pulling a wire along at least one adhesive joint to cut the at least one adhesive joint.

[0048] This aspect of the present invention corresponds to a method for removing a battery installed using the method according to the first aspect of the present invention. Accordingly, a vehicle on which this method is carried out may include any of the features described above with respect to the first aspect of the present invention.

[0049] As shown above, this method utilizes the technique described in relation to a first aspect of the present invention to cut the adhesive joint by wire. This overcomes the major drawback of adhesive joints when compared to mechanical fasteners (which is the difficulty in removing the bonded battery pack). This method can be used to cut any type of adhesive joint described above in relation to a first aspect of the present invention.

[0050] It should be noted that pulling the wire through the adhesive joint can be a manual process or can be assisted by a tool or machine.

[0051] In some embodiments, the passenger car further includes a conduit that crosses at least one of the adhesive joints, and the method includes the steps of aligning a wire through the conduit and using the end of the wire on either side of the conduit to pull the wire along the at least one adhesive joint to cut the at least one adhesive joint. The method can typically be carried out when both sides of the conduit are accessible to an engineer.

[0052] In another embodiment, the passenger car includes a wire, the first end of which is fixed to a frame or battery pack, and the method includes the steps of taking out a portion of the wire (typically a second end) and pulling the wire through at least one adhesive joint by the portion to cut at least one adhesive joint.

[0053] In any of the embodiments described above, the method may further include a step of heating the adhesive and / or the wire before pulling the wire through at least one adhesive joint, preferably the step of heating the wire includes a step of passing an electric current through the wire. This can facilitate the breaking of the adhesive joint. In embodiments where the first end of the wire is fixed to a frame or battery pack and the wire is to be heated using an electric current, preferably the fixing point connects the wire to a circuit for heating the wire. When in use, the technician can take the second end of the wire and complete the circuit to achieve heating of the wire.

[0054] According to a third aspect of the present invention, a passenger car is provided which includes a vehicle frame defining at least the floor portion of the vehicle body, and a battery pack in the floor portion of the vehicle body, wherein the battery pack is bonded to the frame by at least one adhesive joint located at the interface between the battery pack and the frame.

[0055] A vehicle according to this embodiment corresponds to a vehicle manufactured using the method according to the first embodiment of the present invention. Accordingly, the vehicle may include any of the features described above with respect to the first embodiment of the present invention.

[0056] Preferably, one or more adhesive joints are arranged along the periphery of the battery pack. More preferably, one or more adhesive joints are arranged along at least two opposing periphery of the battery pack. Most preferably, one or more adhesive joints substantially surround the central region of the battery pack.

[0057] In many embodiments, the battery pack includes one or more peripheral flanges that form at least a portion of the interface with the frame, and one or more adhesive joints are arranged along one or more of the peripheral flanges.

[0058] Preferably, the interface between the battery pack and the frame includes one or more portions defining a substantially stepped interface, and preferably, at least one adhesive joint is located on one or at least two different surfaces of the portions defining the substantially stepped interface.

[0059] In some embodiments, the vehicle floor portion generally defines a plane, and the interface between the battery pack and the frame includes one or more portions positioned at a predetermined angle to the plane defined by the floor portion, with at least one adhesive joint located on the one or more portions of the interface positioned at a predetermined angle to the plane defined by the floor portion. Preferably, the interface between the battery pack and the frame includes portions positioned at different angles to the plane defined by the floor portion, with at least one adhesive joint located on the portions of the interface positioned at different angles to the plane defined by the floor portion. For the most advantageous handling of impact forces, preferably, one or more portions of the interface between the battery pack and the frame are positioned at an angle that is generally inclined toward or away from the center of the battery pack.

[0060] Preferably, the thickness of each adhesive joint is at least 0.5 mm, preferably at least 1 mm, more preferably at least 2 mm, and most preferably at least 3 mm. Also, preferably, each adhesive joint is elongated.

[0061] In some embodiments, the frame defines an opening through the frame in the floor portion, and the battery pack closes the opening, thereby defining at least a portion of the vehicle's floor. In other embodiments, the frame defines a substantially continuous floor surface in the floor portion of the vehicle body, and the battery pack is positioned substantially adjacent to the floor surface.

[0062] Many embodiments utilize both adhesive joints and mechanical fasteners. In such cases, the vehicle further includes one or more mechanical fasteners located at the interface between the battery pack and the frame, which, together with the adhesive joints, hold the battery pack in place on the frame.

[0063] Preferably, the frame includes opposing longitudinal structural members positioned along opposing longitudinal edges of the floor portion of the vehicle body, and the battery pack is substantially positioned between the opposing longitudinal structural members in the floor portion of the vehicle body.

[0064] The vehicle may also be provided with any of the described features to allow the adhesive joints to be conveniently cut. Preferably, the vehicle includes a conduit that crosses at least one of the adhesive joints, and a wire can be inserted through the conduit to cut at least one adhesive joint. Preferably, the conduit is arranged such that a first end of the conduit is accessible from a first side of the adhesive joint and a second end of the conduit is accessible from a second side of the adhesive joint. In other embodiments, the frame or battery pack includes at least one wire for cutting at least one adhesive joint, the first end of the wire being fixed to the frame or battery pack, and the battery pack is mounted to the frame such that a portion of the wire is accessible to pull the wire through at least one adhesive joint to cut at least one adhesive joint. The vehicle may further include a conduit that crosses at least one of the adhesive joints, the first end of which is fixed to the frame or battery pack at the first side of the conduit, and the wire is positioned such that a portion of the wire is accessible from the second side of the conduit, or the wire is positioned such that a portion of the wire is accessible from the second side of the conduit through the conduit. The wire may be positioned to substantially follow the path of at least one adhesive joint along the interface between the battery pack and the frame.

[0065] The present invention will now be described with reference to the accompanying drawings. [Brief explanation of the drawing]

[0066] [Figure 1] This is a top view of a portion of the vehicle body, including the installed battery pack. [Figure 2] This figure shows a schematic cross-section passing through the vehicle body and battery pack. [Figure 3] This is a schematic top view of the battery pack shown in Figure 1, with the vehicle body omitted. [Figure 4A] This figure shows an alternative schematic cross-section of the vehicle body with the installed battery pack. [Figure 4B] This figure shows an alternative schematic cross-section of the vehicle body with the installed battery pack. [Figure 4C] This figure shows an alternative schematic cross-section of the vehicle body with the installed battery pack. [Figure 4D] This figure shows an alternative schematic cross-section of the vehicle body with the battery pack installed. [Figure 4E] This figure shows an alternative schematic cross-section of the vehicle body with the installed battery pack. [Figure 5] This figure shows a magnified detail of a schematic cross-section of the vehicle body with the installed battery pack. [Figure 6] This is a schematic top view of the installed battery pack, with the vehicle body omitted. [Figure 7] This is a schematic top view of the installed battery pack, with the vehicle body omitted. [Figure 8] This is a flow diagram illustrating how to attach a battery pack to the vehicle body. [Figure 9] This is a flow diagram illustrating the method for removing the battery pack installed in the vehicle. [Modes for carrying out the invention]

[0067] Here, the embodiments will be described in detail with reference to Figures 1 to 3.

[0068] Figure 1 shows a portion of the vehicle body 1. The vehicle body includes a frame 10. This frame can be a so-called body-in-white (BIW). Figure 1 shows a floor frame section, which includes opposing longitudinal structural members 11a, 11b, corresponding to the rocker or door sill area of ​​the vehicle body. This floor frame can be part of the BIW or it can be a separate frame part that will later be assembled into the BIW. The longitudinal structural members 11a, 11b extend along the longitudinal length of the vehicle's cabin between the front and rear wheels and typically include a crash-absorbing structure designed to absorb a side impact crash. The frame 10 also includes a front lateral structural member 12 extending between the longitudinal structural members 11a, 11b immediately behind the front wheel area of ​​the main body, and a rear lateral structural member 13 extending between the longitudinal structural members 11a, 11b immediately in front of the rear wheel area of ​​the main body. Accordingly, the lateral and longitudinal structural members define the boundaries of the vehicle body's floor portion. The vehicle body's floor portion generally defines the floor plane, which is substantially parallel to the ground. The lateral and longitudinal structural members also define a generally rectangular opening through the floor portion in the vertical direction, with truncated corners 14, in which the battery pack 20 is located. The front lateral structural member 12 is connected to the front impact structure 2 and is designed to transmit front impact forces along the longitudinal structural members 11a, 11b and around the battery pack 20. Similarly, the rear lateral structural member 13 is connected to the rear impact structure 3 and is designed to transmit rear impact forces along the longitudinal structural members 11a, 11b and around the battery pack 20.

[0069] As described above, the battery pack 20 is positioned in an opening 14 through the frame 10. The battery pack includes a main housing 21, within which multiple battery modules are arranged together with other battery components. The shape of the battery pack 20 generally corresponds to the shape of the opening 14 through the frame 10. The battery pack is generally planar, having a transverse width that is similar in dimensions to the width of the frame and a longitudinal length that is similar in dimensions to the length of the frame, but relatively small in the vertical direction and intended to sit substantially on the floor of the vehicle. The peripheral edge of the battery pack 20 surrounding the main housing 21 has a peripheral flange 22. In this embodiment, the battery pack is inserted into the frame from below, and the flange 22 extends from the lower side of the battery pack so as to be away from the central axis of the battery pack perpendicular to the general plane of the battery pack. The flange has a thickness smaller than the main housing 21 of the battery pack in the vertical direction. Therefore, when inserted from below into the frame 10, the peripheral flange 22 can engage with the lateral structural members 12, 13 and the longitudinal structural members 11a, 11b along each side of the battery pack 20, while most of the main housing 21 is seated inside the opening 14, substantially between the lateral structural members 12, 13 and the longitudinal structural members 11a, 11b. Figure 2 shows a cross-section through the frame in a plane extending along the vertical and transverse directions, showing that the main housing of the battery is positioned between the longitudinal structural member 11a and the longitudinal structural member 11b, with the upper surface of the flange 22 and the vertical side wall of the housing 21 forming an interface with the frame 10.

[0070] In this embodiment, the battery pack 20 is mounted to the frame 10 using an adhesive joint 30, which is shown in Figures 2 and 3. As can be seen in Figure 2, the adhesive joint is positioned on the upper surface of the peripheral flange 22 of the battery pack, connecting the peripheral flange to the lower surfaces of the lateral structural members 11a, 11b. The lower surfaces of the lateral structural members 12, 13 and the longitudinal structural members 11a, 11b are defined as complementary rims around the opening 14 that engage with the peripheral flange. This interface between the upper surface of the flange 22 and the lower surfaces of the lateral structural members 12, 13 and the longitudinal structural members 11a, 11b is shown as a flat surface, but it will be recognized that any complementary interface may be used.

[0071] Figure 3 shows a top view of the battery pack 20 with the frame 10 omitted, allowing the path followed by the adhesive joint 30 to be seen. As shown in Figure 3, the main housing of the battery pack has a generally rectangular footprint with rounded corners to match the shape of the opening 14 through the frame. Around the entire periphery of this main housing 21, the peripheral flange 22 extends from the lower surface of the battery pack, with a step-down from the upper surface of the battery pack to the upper surface of the peripheral flange 22. The adhesive joint 30 is provided in a single continuous path that extends around the entire peripheral flange 22 of the battery pack 20, surrounding the main housing 21. This allows the battery pack to be coupled to the frame 10 around the entire periphery of the battery pack.

[0072] The adhesive used for the adhesive joint 30 can be a ductile structural adhesive with polyurethane chemistry. The materials for the battery case housing 21 and flange 22 can be composite materials including a resin matrix, reinforcing fibers, and metal inserts. For example, the material for the battery case housing 21 can be carbon fiber reinforced polypropylene, which can have a Young's modulus of >20 GPa. In an alternative embodiment, the housing can be formed from aluminum, which can have a Young's modulus of approximately 70 GPa. The frame 10 can be made from an aluminum alloy assembly. While these materials are typical, in principle, any combination of materials for the battery pack and frame can be used with an appropriate adhesive to bond those materials together.

[0073] Figures 1 to 3 illustrate one possible interface and mounting arrangement for the battery pack 20 and frame 10, but various other mounting arrangements are also possible. Herein, several alternative configurations will be described with reference to Figures 4A to 4E, each of which is an alternative cross-section through the frame 10 in a plane extending along the vertical and transverse directions. The differences between these alternative embodiments and the embodiments in Figures 1 to 3 will be described here.

[0074] Figure 4A shows one embodiment in which the frame 10 is further provided with a flange 16 that partially protrudes into the opening 14 from the sidewalls of the lateral structural members 12, 13 and longitudinal structural members 11a, 11b to engage with the upper surface of the main housing 21 of the battery pack 20. This defines a substantially stepped interface between the battery pack 20 and the frame 10. The battery pack is additionally bonded to the frame 10 by a second adhesive joint 31 positioned between the lower surface of the flange 16 of the frame 10 and the upper surface of the main housing 21 of the battery pack. This second adhesive joint can be provided to extend around the entire periphery of the upper surface of the main housing 21, or it can extend only partially around the periphery. This second adhesive joint increases the strength of the bond between the battery pack 20 and the frame 10.

[0075] Figure 4B shows one embodiment in which the interface between the frame 10 and the battery pack 20 is the same as that in Figures 1 to 3. However, in this embodiment, a second adhesive joint 31 is provided between the vertical side wall of the main housing 21 of the battery pack 20 and the inner side walls of the lateral structural members 12, 13 and the longitudinal structural members 11a, 11b (which face the opening 14). This second adhesive joint not only increases the strength of the joint between the battery pack 20 and the frame 10, but also ensures that the two adhesive joints will experience the same forces in different relative directions by arranging the two adhesive joints on surfaces that are at an angle to each other. For example, a lateral impact force may create a shear force on the first adhesive joint 30, but may create a compressive force on the second adhesive joint 31. This reduces the risk that both adhesive joints will fail as a result of the same impact.

[0076] Figure 4C shows one embodiment in which the interface between the battery pack 20 and the frame 10 is the same as that described with reference to Figure 4A, and includes a flange 16 that partially protrudes from the side walls of the lateral structural members 12, 13 and the longitudinal structural members 11a, 11b into the opening 14. However, in this embodiment, there is no adhesive joint provided along the interface between the flange 16 and the upper surface of the battery pack body housing 21. Instead, the interface between the flange 16 and the upper surface of the body housing 21 is provided with a plurality of mechanical fasteners 40a, 40b. Although only two mechanical fasteners are shown in the cross section of Figure 4C, it will be recognized that it is possible to provide mechanical fasteners at multiple locations around the interface between the battery pack 20 and the frame 10. In this embodiment, the mechanical fasteners include bolts. Threaded bolt shafts are provided protruding from the upper surface of the battery pack body housing 21. These bolt shafts are received into corresponding holes through the flange 16 and secured by nuts, so that the battery pack is bolted to the frame. In this embodiment, bolts are described as mechanical fasteners, but it will be recognized that any type of mechanical fastener, including clips, pins, or rivets, may be used. In this embodiment, the use of mechanical fasteners 40a, 40b in addition to the adhesive joint 30 between the flange 22 of the battery pack 20 and the frame ensures that the battery mount is more resilient to different failure modes that affect each joint type individually. Mechanical fasteners may also be useful for seating the battery pack and for holding the battery pack in place while the adhesive dries.

[0077] Figure 4D shows one embodiment in which a substantially continuous floor surface 15 extends between the lateral structural members 12, 13 and the longitudinal structural members 11a, 11b, so as to be the absence of openings passing through the frame in the vertical direction. In this embodiment, the battery pack is attached to the frame by adhesive joints 30, which again are provided in a single continuous path extending around the entire peripheral flange 22 of the battery pack 20 so as to surround the main housing 21. Additionally, mechanical fasteners 40a, 40b are again provided in the form of bolts, with threaded bolt shafts provided to protrude from the upper side of the main housing 21 of the battery pack, but in this embodiment are received in corresponding holes passing through the substantially continuous floor surface 15.

[0078] Figure 4E shows an embodiment that differs from the embodiment in Figure 4D in that the interface between the battery pack and the frame (with adhesive joints provided along it) includes portions positioned at an oblique angle to the horizontal plane. In particular, instead of the peripheral flange 22 extending in the horizontal plane, in this embodiment the flange 22a is provided at an angle that tilts downward away from the main housing 21 of the battery pack. As shown in Figure 4E, this means that the angle the flange makes with respect to the horizontal (i.e., the plane of the floor and the battery pack) on the left side of Figure 4E is rotated counterclockwise by approximately 10°, and on the right side of Figure 4E it is rotated clockwise by approximately 10°. Although not shown in this figure, flanges along the front and rear edges of the battery pack 20 are similarly tilted downward away from the main housing 21 of the battery pack. The lower surfaces of the lateral structural members 12, 13 and the longitudinal structural members 11a, 11b are inclined in a complementary manner, i.e., inclined downward toward the center away from the frame. The adhesive joint 30 is provided between the inclined upper surface of the flange 22a and the inclined lower surfaces of the lateral structural members 12, 13 and the longitudinal structural members 11a, 11b. This interface shape means that lateral impact forces will place the adhesive joint in a partially compressive state rather than a purely shear state, which means that it is less likely to break.

[0079] It will be recognized that the various features described above with respect to alternative cross-sections can be combined as desired. For example, the inclined flange 22a in Figure 4E can be provided in any embodiment of Figure 2 or Figures 4A to 4D. Similarly, the second adhesive joint 31 on the vertical side wall in Figure 4B can be provided in any of the other embodiments.

[0080] Figure 5 shows an enlarged portion of the frame and battery pack constructed in substantially the same manner as described with reference to Figures 1 to 3. However, in this embodiment, a conduit 50 is provided across the adhesive joint 30. This conduit can be a passage through the adhesive joint, created by including a wire inside the adhesive before the adhesive hardens. Alternatively, this conduit can be a small tube made of a soft, thin rubbery or polymer material (e.g., EPDM or ABS) with a diameter of approximately 2 mm, extending across the adhesive joint 30. In this embodiment, the conduit follows a path beginning at a first end 51 so as to be accessible from the outside of the frame, the first end 51 located at the very outer edge of the peripheral flange in an opening to the gap between the flange and the lower surface of the longitudinal structural member. The conduit extends from this first end 51 across the adhesive joint toward the center of the battery pack. The conduit follows the interface between the frame 10 and the battery pack 20 until it reaches an opening through the frame. Thus, the second end 52 of the conduit is accessible through the opening 14 through the frame 10 near the upper surface of the main housing 21 of the battery pack 20. As will be described in more detail below, this conduit can be used when removing the battery pack from the frame. In particular, a technician can insert a cutting wire through the first or second end 51, 52 along the conduit 50 and pull the wire out at the opposite end. With the wire in this position, a technician can pull the wire through the adhesive joint along the path of the adhesive joint around the battery pack 20, cut the adhesive joint, and allow the battery pack to be removed.

[0081] An alternative embodiment that allows for the removal of the battery pack 20 is shown in Figure 6, which shows a top view of the battery pack. This battery pack has a substantially square contour and again includes a main housing 21 that holds the battery module, etc., and a peripheral flange 22 extending therefrom. Again again, an adhesive joint 30 is provided that extends along this peripheral flange 22 and surrounds the main housing 21 of the battery pack 20. In this embodiment, a single cutting wire 60 is provided on the battery pack. This wire can be made from stainless steel and, for example, can have a diameter of 1 mm. The wire can have a circular cross-section or a square or rectangular cross-section, and can define a sharper cutting edge. Alternatively, the wire can be a braided cutting wire. Most of the length of the wire extends along the peripheral flange 22 which is positioned between the main housing 21 and the adhesive joint 30. The wire can be weakly bonded to the flange 22 by small dots of adhesive. The first end 61 of the cutting wire 60 is fixed to the battery pack. In this embodiment, the first end is fixed adjacent to the upper left corner of the main housing 21, as shown in Figure 6. The cutting wire follows a path that extends entirely around the main housing 21, counterclockwise in Figure 6. A short section of the wire overlaps itself after completing one entire path around the main housing 21, and then the second end of the wire passes through a conduit 50 provided across the adhesive joint 30. Thus, the free second end is provided at the outer edge of the battery pack 20, where it can be accessed by a technician. To cut the adhesive, the technician only needs to take the second end 62 of the wire, pull the wire through the adhesive joint, and follow the path of the adhesive joint around the battery pack 20.

[0082] An alternative embodiment is shown in Figure 7. This embodiment differs from Figure 6 in that four separate adhesive joints are provided along the respective edges of the battery pack, corresponding to the edges of the lateral structural members 12, 13 and the longitudinal structural members 11a, 11b, respectively. In this embodiment, the second end 62 of the wire can simply be provided through the gap between two adjacent adhesive joints, allowing the second end of the wire to be accessible along the outer edge of the battery pack 20.

[0083] It will be recognized that the types of cutting wires described with respect to Figures 6 and 7 can be provided in any of the embodiments described above with respect to Figures 1 to 4E.

[0084] Next, the process of attaching the battery pack to the vehicle frame will be described with further reference to Figure 8. First, in step S101, a vehicle frame forming the floor of the vehicle is provided, and in step S102, a battery pack to be attached to the frame is provided. The frame 10 may be any of the frames described above, particularly with respect to Figures 1 to 4E, and the battery pack 20 may be the corresponding battery pack described above.

[0085] In step S103, a cutting wire 60 is provided. The first end 61 of the cutting wire is fixed to the battery pack 20 at a point where it lies in the adhesive joint to be applied in the next step. For this purpose, any suitable anchoring member, such as an eyebolt, can be used to which the wire is tied. The wire is provided to extend around the battery pack 20 along a path that is slightly inside the path of the adhesive joint to be applied in a subsequent step, almost the entire circumference of the battery pack 20. As described above, small dots of adhesive can be applied at regular intervals along the path of the wire to hold the wire in place on the battery pack 20.

[0086] In step S104, a conduit 50 is provided, positioned near the second end 62 of the wire, and positioned to extend across the adhesive joint to be applied in a subsequent step. The second end of the wire 62 is then passed through the conduit 50. It will be recognized that if an integral cutting wire is not to be provided to the battery pack, steps S103 and S104 may be omitted, or if a separate cutting wire is intended to remove the battery pack, the conduit may be positioned so that it extends across the adhesive joint without any wire.

[0087] In step S105, adhesive is applied to the peripheral flange 22 of the battery pack 20. As described above, this adhesive is preferably a paste-like ductile structural adhesive having the chemical properties of polyurethane, and is applied by coating the peripheral flange 22 of the battery pack 20 while the peripheral flange is horizontal and facing upward. The adhesive is applied to a thickness of at least 3 mm to compensate for the surface roughness of the battery pack or frame. The adhesive is applied to define one or more adhesive joints 30, and typically extends around the entire circumference of the battery pack so as to surround the main housing 21 of the battery pack. The adhesive is applied so as to spread into the conduit provided in step S104, and nevertheless, the second end of the wire can be accessed and move freely within the conduit 50.

[0088] In step S106, the battery pack 20 is placed in a predetermined position at the bottom defined by the frame 10. The battery pack is positioned such that the adhesive on the battery pack is at a suitable interface with the frame 10, as described above. In this step, the battery pack 20 can be precisely positioned using any mechanical fasteners 40a, 40b, and therefore, means for guiding and positioning the battery pack to the precise location within the vehicle frame can be included during the positioning step. For example, if the mechanical fasteners include bolts, the bolt shafts and complementary bolt holes can assist in positioning the frame and the battery pack. A similar effect can be achieved without mechanical fasteners using dowel pins or the like.

[0089] Finally, in step S107, the battery pack is joined to the frame using an adhesive joint. This process may involve pressing the battery pack against the frame while the adhesive cures. This may involve simply lowering the frame over the battery pack or pushing the battery pack into the frame, so that the weight of the frame presses the battery pack against the frame and resists the oil pressure generated by the extrusion of the adhesive. However, preferably, mechanical fasteners 40a, 40b are used, which are used to clamp the battery pack against the frame, while the adhesive is set to bond the battery pack to the frame. These mechanical fasteners between the battery pack and the vehicle frame can clamp the two together during bonding to resist the oil pressure generated by the extrusion of the adhesive. Such mechanical fasteners can be driven to a hard stop via a compression limiter so that the gap of the adhesive can be controlled to a precise dimension and hard contact between the vehicle frame and the battery case can be avoided. For example, if the mechanical fasteners include bolts, 3 mm spacing elements can be placed on one or more bolt shafts between the battery pack and the frame to ensure a 3 mm adhesive joint thickness. The mechanical fastener may also exclusively provide a means for holding the battery pack in place while the adhesive is curing, thus allowing subsequent vehicle handling operations while the adhesive is achieving its full strength.

[0090] Next, with further reference to Figure 9, the process of removing a battery pack installed in the manner described above will be explained. In the first step S201, a cutting wire is positioned across the adhesive joint. In the case of an embodiment such as that shown in Figure 5, this can involve passing the cutting wire along a conduit 50 provided across the adhesive joint from a first end 51 to a second end 52 (where the wire is removed). In the case of an embodiment of the kind shown and described in relation to Figures 6 and 7, the cutting wire can be provided pre-positioned across the adhesive joint.

[0091] In step S202, the adhesive and / or wire may be heated. Heating the adhesive may soften it, and heating the wire may cause the wire to come into contact with the adhesive and soften it. The adhesive can be heated by bringing a heat source into contact with the opposite side of the peripheral flange. The wire can be heated by a resistance process. If one end of the wire is fixed to the battery pack or frame, this fixing point may include an electrical connection to a dedicated vehicle circuit accessible from within the vehicle when the vehicle is grounded or the battery is inspected.

[0092] In step S203, the wire is pulled through the adhesive joint. The cutting wire can be pulled along the adhesive joint along its path around the battery pack. Pulling can be done manually or with a tool. If a single cutting wire is used, only one end of the wire needs to be pulled, leaving the other end fixed in place. If separate cutting wires are used, both ends may need to be operated to pull the wire through the adhesive joint. Once the wire has been pulled through its entire path in the adhesive joint, the adhesive is cut.

[0093] In step S204, any mechanical fasteners 40a, 40b can be removed. For example, if the battery pack 20 is also bolted to the frame, the bolts can be removed and the battery pack can be taken out.

[0094] Finally, in step S205, the adhesive joint is cut and all mechanical fasteners are disengaged, and the battery pack is separated from the vehicle frame. [Explanation of Symbols]

[0095] 1. Vehicle body 2 Front collision structure 3 Rear collision structure 10 frames 11a, 11b Vertical structural members 12 Front lateral structural member 13 Rear lateral structural member 14 Opening 15 Substantially continuous floor surface 16 flange 20 Battery Packs 21 Main Housing 22 Peripheral flange 22a Flange 30 Adhesive joint 31 Second adhesive joint 40a, 40b mechanical fasteners 50 Conduit 51 First end 52 Second end 60 Integrated cutting wire 61 First end 62 Second end

Claims

1. A method for attaching a battery pack to the body of a passenger car, The steps include providing a vehicle frame that defines at least the floor portion of the vehicle body, The steps include providing the battery pack, The steps include: placing the battery pack on the floor portion of the vehicle body, The steps of joining the battery pack to the frame using at least one adhesive joint located at the interface between the battery pack and the frame, Methods that include...

2. The method according to claim 1, wherein the one or more adhesive joints are arranged along the peripheral edge of the battery pack.

3. The method according to claim 2, wherein the one or more adhesive joints are arranged along at least two opposing peripheral edges of the battery pack.

4. The method according to any one of claims 1 to 3, wherein the one or more adhesive joints substantially surround the central region of the battery pack.

5. The method according to any one of claims 1 to 4, wherein the battery pack includes one or more peripheral flanges configured to form at least a portion of the interface with the frame, and the one or more adhesive joints are arranged along one or more of the peripheral flanges.

6. The method according to any one of claims 1 to 5, wherein the interface between the battery pack and the frame includes one or more portions defining a substantially stepped interface, and preferably the at least one adhesive bond is located on one or at least two different surfaces of the portion defining the substantially stepped interface.

7. The method according to any one of claims 1 to 6, wherein the floor portion of the vehicle generally defines a plane, the interface between the battery pack and the frame includes one or more portions positioned at a predetermined angle with respect to the plane defined by the floor portion, and the at least one adhesive joint is positioned on the one or more portions of the interface positioned at a predetermined angle with respect to the plane defined by the floor portion.

8. The method according to claim 7, wherein the interface between the battery pack and the frame includes portions positioned at different angles with respect to the plane defined by the floor portion, and the at least one adhesive joint is positioned in the portion of the interface positioned at different angles with respect to the plane defined by the floor portion.

9. The method according to claim 7 or 8, wherein one or more portions of the interface between the battery pack and the frame are arranged at an angle that is generally inclined toward or away from the center of the battery pack.

10. The method according to any one of claims 1 to 9, wherein the thickness of each adhesive joint is at least 0.5 mm, preferably at least 1 mm, more preferably at least 2 mm, and most preferably at least 3 mm.

11. The adhesive joint or each of the adhesive joints is elongated, according to the method according to any one of claims 1 to 10.

12. The method according to any one of claims 1 to 11, wherein the frame defines an opening in the floor portion through the frame, and the battery pack closes the opening, thereby defining at least the area of ​​the floor of the vehicle.

13. The method according to any one of claims 1 to 11, wherein the frame defines a substantially continuous floor surface in the floor portion of the vehicle body, and the battery pack is disposed substantially adjacent to the floor surface.

14. The method according to any one of claims 1 to 13, wherein the step of placing the battery pack on the floor portion of the vehicle body includes the step of engaging one or more mechanical fasteners to guide the battery pack to a predetermined location on the frame.

15. The method according to any one of claims 1 to 14, wherein the step of joining the battery pack to the frame includes the step of clamping the battery pack to the frame using one or more mechanical fasteners while the adhesive is curing.

16. The method according to claim 14 or 15, wherein the one or more mechanical fasteners include one or more spacing elements configured to prevent direct contact between the battery pack and the frame.

17. The method according to any one of claims 1 to 16, wherein the frame includes opposing structural members, and the method includes the steps of positioning the battery pack between the opposing structural members and joining the battery pack to each of the opposing structural members, preferably the step of joining the battery pack to one or more of the opposing structural members includes joining the battery pack to the structural member using an adhesive joint located at the interface between the battery pack and the structural member.

18. The method according to claim 17, as dependent on any one of claims 7 to 9, wherein the opposing structural members define one or more portions that are positioned at a predetermined angle with respect to the plane defined by the floor portion, preferably each opposing structural member defines a portion that is positioned at a predetermined angle with respect to the plane defined by the floor portion, and the at least one adhesive joint is preferably positioned in each of the portions that are positioned at a predetermined angle with respect to the plane defined by the floor portion.

19. The frame defines at least a portion of the floor surface in the floor portion of the vehicle body and a structural member extending away from the floor surface, the method further comprising the steps of joining the battery pack to the structural member and joining the battery pack to the floor surface of the frame, preferably the step of joining the battery pack to the structural member comprising joining the battery pack to the structural member using an adhesive joint located at the interface between the battery pack and the structural member, and / or preferably the step of joining the battery pack to the floor surface comprising joining the battery pack to the floor surface using an adhesive joint located at the interface between the battery pack and the floor surface, the method according to any one of claims 1 to 18.

20. The method according to any one of claims 1 to 19, wherein the frame includes opposing longitudinal structural members arranged along opposing longitudinal edges of the floor portion of the vehicle body, and the step of placing the battery pack in the floor portion of the vehicle body includes the step of substantially placing the battery pack between the opposing longitudinal structural members.

21. The method according to any one of claims 1 to 20, wherein the material of the battery pack at the location of the adhesive joint has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, and most preferably at least 20 GPa.

22. The method according to any one of claims 1 to 21, wherein the battery pack includes a housing, and the material of the housing extending between the adhesive joint and either another joint between the battery pack and the frame or another section of the same adhesive joint has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, and most preferably at least 20 GPa.

23. The method according to claim 22, as at least dependent on claim 17, wherein the material of the housing extending between the opposing structural members has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, and most preferably at least 20 GPa.

24. The method according to any one of claims 1 to 23, wherein the step of joining the battery pack to the frame using at least one adhesive joint includes the step of providing a conduit across at least one of the adhesive joints, and a wire is to be inserted through the conduit to cut the at least one adhesive joint.

25. The method according to claim 24, wherein the conduit is arranged such that a first end of the conduit is accessible from a first side of the adhesive joint and a second end of the conduit is accessible from a second side of the adhesive joint.

26. The method according to any one of claims 1 to 25, further comprising the step of providing the frame or the battery pack with at least one wire for cutting the at least one adhesive joint, the first end of the wire being fixed to the frame or the battery pack, and the battery pack being positioned and coupled to the frame such that a portion of the wire is accessible for pulling the wire through the at least one adhesive joint to cut the at least one adhesive joint.

27. The method according to claim 26, further comprising the step of providing a conduit across at least one of the adhesive joints, wherein the first end of the wire is fixed to the frame or the battery pack at a first side of the conduit, and the wire is arranged to pass through the conduit such that a portion of the wire is accessible from a second side of the conduit, or the wire is arranged so that a portion of the wire is accessible through the conduit from a second side of the conduit.

28. The method according to claim 26 or 27, wherein the wire is arranged to substantially follow the path of the at least one adhesive joint along the interface between the battery pack and the frame.

29. A vehicle body for a passenger car, A vehicle frame defining at least the floor portion of the vehicle body, A battery pack located in the floor portion of the vehicle body, wherein the battery pack is connected to the frame by at least one adhesive joint located at the interface between the battery pack and the frame, The vehicle body, including the body itself.

30. The vehicle body according to claim 29, wherein the one or more adhesive joints are arranged along the periphery of the battery pack.

31. The vehicle body according to claim 30, wherein the one or more adhesive joints are arranged along at least two opposing peripheral edges of the battery pack.

32. The vehicle body according to any one of claims 29 to 31, wherein the one or more adhesive joints substantially surround the central region of the battery pack.

33. The vehicle body according to any one of claims 29 to 32, wherein the battery pack includes one or more peripheral flanges configured to form at least a portion of the interface with the frame, and the one or more adhesive joints are arranged along one or more of the peripheral flanges.

34. The vehicle body according to any one of claims 29 to 33, wherein the floor portion of the vehicle generally defines a plane, the interface between the battery pack and the frame includes one or more portions positioned at a predetermined angle with respect to the plane defined by the floor portion, and the at least one adhesive joint is positioned on the one or more portions of the interface positioned at a predetermined angle with respect to the plane defined by the floor portion.

35. The vehicle body according to claim 34, wherein the interface between the battery pack and the frame includes portions positioned at different angles with respect to the plane defined by the floor portion, and the at least one adhesive joint is positioned on the portion of the interface positioned at different angles with respect to the plane defined by the floor portion.

36. The vehicle body according to claim 34 or 35, wherein one or more portions of the interface between the battery pack and the frame are arranged at an angle that is generally inclined toward or away from the center of the battery pack.

37. The vehicle body according to any one of claims 29 to 36, wherein the thickness of each adhesive joint is at least 0.5 mm, preferably at least 1 mm, more preferably at least 2 mm, and most preferably at least 3 mm.

38. The vehicle body according to any one of claims 29 to 37, wherein the adhesive joint or each of the adhesive joints is elongated.

39. The vehicle body according to any one of claims 29 to 38, wherein the frame defines an opening in the floor portion through the frame, and the battery pack closes the opening, thereby defining at least the floor area of ​​the vehicle.

40. The vehicle body according to any one of claims 29 to 38, wherein the frame defines a substantially continuous floor surface in the floor portion of the vehicle body, and the battery pack is disposed substantially adjacent to the floor surface.

41. The vehicle body according to any one of claims 29 to 40, wherein the battery pack is further joined to the frame by one or more mechanical fasteners.

42. The vehicle body according to claim 41, wherein the one or more mechanical fasteners include one or more spacing elements configured to prevent direct contact between the battery pack and the frame.

43. The vehicle body according to any one of claims 29 to 42, wherein the frame includes opposing structural members, the battery pack is positioned between the opposing structural members, the battery pack is joined to each of the opposing structural members, preferably the battery pack is joined to one or more of the opposing structural members by an adhesive joint located at the interface between the battery pack and the structural members.

44. The vehicle body according to claim 43, as dependent on any one of claims 34 to 36, wherein the opposing structural members define one or more portions that are positioned at a predetermined angle with respect to the plane defined by the floor portion, preferably each opposing structural member defines a portion that is positioned at a predetermined angle with respect to the plane defined by the floor portion, and the at least one adhesive joint is preferably positioned in each of the portions that are positioned at a predetermined angle with respect to the plane defined by the floor portion.

45. The vehicle body according to any one of claims 29 to 44, wherein the frame defines at least a portion of the floor surface in the floor portion of the vehicle body and a structural member extending away from the floor surface, the battery pack is bonded to the structural member, the battery pack is bonded to the floor surface of the frame, preferably the battery pack is bonded to the structural member using an adhesive joint located at the interface between the battery pack and the structural member, and / or the battery pack is bonded to the floor surface using an adhesive joint located at the interface between the battery pack and the floor surface.

46. The vehicle body according to any one of claims 29 to 45, wherein the frame includes opposing longitudinal structural members arranged along opposing longitudinal edges of the floor portion of the vehicle body, and the battery pack is substantially positioned between the opposing longitudinal structural members.

47. The vehicle body according to any one of claims 29 to 46, wherein the material of the battery pack at the location of the adhesive joint has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, and most preferably at least 20 GPa.

48. The vehicle body according to any one of claims 29 to 47, wherein the battery pack includes a housing, and the material of the housing extending between the adhesive joint and either another joint between the battery pack and the frame or another section of the same adhesive joint has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, and most preferably at least 20 GPa.

49. The vehicle body according to claim 48, as at least dependent on claim 43, wherein the material of the housing extending between the opposing structural members has a Young's modulus of at least 1 GPa, preferably at least 2 GPa, more preferably at least 3 GPa, more preferably at least 5 GPa, more preferably at least 10 GPa, and most preferably at least 20 GPa.

50. The vehicle body according to any one of claims 29 to 49, wherein a conduit is provided across at least one of the adhesive joints, and a wire can be inserted through the conduit to cut the at least one adhesive joint.

51. The vehicle body according to claim 50, wherein the conduit is arranged such that a first end of the conduit is accessible from a first side of the adhesive joint, and a second end of the conduit is accessible from a second side of the adhesive joint.

52. The vehicle body according to any one of claims 29 to 51, wherein the frame or the battery pack is provided with at least one wire for cutting the at least one adhesive joint, the first end of the wire being fixed to the frame or the battery pack, and the battery pack being positioned and coupled to the frame such that a portion of the wire is accessible for pulling the wire through the at least one adhesive joint to cut the at least one adhesive joint.

53. The vehicle body according to claim 52, further comprising a conduit provided across at least one of the adhesive joints, the first end of the wire being fixed to the frame or the battery pack at a first side of the conduit, the wire being arranged to pass through the conduit such that a portion of the wire is accessible from a second side of the conduit, or the wire being arranged such that a portion of the wire is accessible through the conduit from a second side of the conduit.

54. The vehicle body according to claim 52 or 53, wherein the wire is arranged to substantially follow the path of the at least one adhesive joint along the interface between the battery pack and the frame.

55. A method for removing a battery pack mounted on the body of a passenger car, the passenger car comprising a vehicle frame defining at least a floor portion of the body, and a battery pack located in the floor portion of the body, the battery pack being coupled to the frame by at least one adhesive joint located at an interface between the battery pack and the frame, the method comprising the step of pulling a wire through the at least one adhesive joint to cut the at least one adhesive joint.

56. The passenger car further includes a conduit that crosses at least one of the adhesive joints, and the method comprises the steps of aligning the wire through the conduit and using the end of the wire on either side of the conduit to pull the wire along the at least one adhesive joint to cut the at least one adhesive joint.

57. The method according to claim 55, wherein the passenger car includes the wire, the first end of the wire being fixed to the frame or the battery pack, and the method includes the steps of taking out a portion of the wire and pulling the wire through the at least one adhesive joint by the portion to cut the at least one adhesive joint.

58. The method according to any one of claims 55 to 57, further comprising the step of heating the adhesive and / or the wire before pulling the wire through the at least one adhesive joint, preferably the step of heating the wire comprising passing an electric current through the wire.

59. The method according to any one of claims 55 to 58, applied to a vehicle body according to any one of claims 29 to 54.

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