Automotive traction battery with valve protection cover

Abstract

The present invention relates to an automotive traction battery (20) comprising a tray (22) for housing battery cells, at least one valve (38, 40) positioned on a vertical wall (30) of the tray (22), and a protective cover (54) fixed to the outer surface (58) of the vertical wall (30) and covering at least one valve (38, 40), wherein the cover (54) comprises at least one lower rim (62), the lower rim (62) having a free edge (63) in contact with the outer surface (58) of the vertical wall (30) and intended to block water jets directed toward at least one valve (38, 40), and the lower rim (62) comprises a water drainage opening (65).

Description

Technical Field

[0001] The present invention relates to

[0002] - a tray for accommodating battery cells,

[0003] - at least one valve arranged on the vertical wall of the tray,

[0004] - a protective cover fixed to the outer surface of the vertical wall covering the at least one valve, and relates to a traction battery for an automobile.

Background Art

[0005] Automobiles propelled by an electric motor, such as hybrid vehicles or electric vehicles, comprise a traction battery sized to supply an electric traction motor.

[0006] Such automobiles are equipped with a traction battery disposed under the chassis of the vehicle. For example, the traction battery is suspended with a small lateral clearance in a housing opening at the bottom of the vehicle structure such that the lower surface of the battery pack forms the underside of the vehicle. This facilitates the removal and installation of the battery pack.

[0007] According to another known design, the traction battery is suspended from a rigid element of the chassis, such as a structural cross member, by direct attachment to a battery tray. Thus, the chassis does not comprise a housing.

[0008] Such a traction battery comprises battery cells surrounded by a tray. The tray is sealed to prevent harmful substances from entering the tray into the battery.

[0009] When using a traction battery, the battery cells release volatile substances that gradually accumulate in the tray. This causes the pressure in the tray to gradually increase. If the pressure becomes too high, there is a risk of damaging or even exploding the traction battery.

[0010] To avoid this problem, battery trays are generally equipped with a safety valve, often referred to by the acronym "PRV," which stands for "pressure relief valve." This safety valve opens under the influence of the internal pressure in the tray, opening an orifice that allows volatile substances to escape to the outside of the tray.

[0011] The traction battery is advantageously equipped with two safety valves, a first valve called "PRD" which stands for "pressure release device," and a second valve manufactured by "NITTO." The first valve opens under the influence of heat, and the second valve opens under the influence of internal pressure.

[0012] The valve is located on the vertical wall of the battery. To function effectively, the valve opens into the free space between the battery and its adjacent components. This free space is open directly beneath the vehicle. Therefore, the valve can be freely accessed from beneath the vehicle. Consequently, the valve is exposed to splashes, especially from liquids, when the vehicle is in motion. This is generally not a problem, as the valve is equipped with an annular seal, specifically a lip seal, which ensures that the orifice that the valve closes is properly sealed when the valve is closed.

[0013] It is also known that high-pressure washer systems are used to wash automobiles by spraying water at high pressure. For example, the water is compressed to 80 to 150 bar before being released as a jet.

[0014] In this way, the traction battery valves are exposed and vulnerable to impact from high-pressure water jets. Generally, a valve flap covers the seal, protecting it when water jets are released perpendicular to the wall housing the valve.

[0015] However, it was found that when high-pressure water is sprayed in a direction inclined relative to the wall containing the valve, it is highly likely to reach the valve seal directly. In this case, the pressure of the sprayed water is sufficient to deform the seal and allow water to enter the inside of the traction battery. This can damage the battery cells in the tray.

[0016] It is already known from French Patent Application Publication No. 2.987.807 that a horizontal fairing is placed beneath the vehicle chassis to improve the vehicle's aerodynamics by sealing all gaps present around the battery. Such a fairing extends as an extension of the underside of the traction battery tray. This type of fairing surrounds the battery and prevents high-pressure water jets from reaching the valve.

[0017] However, such fairings are made up of bulky, complexly shaped parts that are expensive to manufacture and install on the vehicle. Therefore, such solutions are very costly.

[0018] If the battery is already mounted under the chassis, the fairing must be attached and removed regularly.

[0019] Therefore, it is necessary to effectively and inexpensively prevent water from entering the battery through the valve. [Overview of the project]

[0020] The present invention

[0021] - A tray for housing battery cells,

[0022] - At least one valve located on the vertical wall of the tray,

[0023] -A protective cover fixed to the outer surface of the vertical wall, covering at least one of the valves, Equipped with,

[0024] The cover has at least one lower rim, the free edge of the lower rim contacts the outer surface of the vertical wall, the lower rim is intended to block the injected water directed towards said at least one valve, and the lower rim has a water discharge orifice, which is characterized by It relates to a traction battery for a motor vehicle.

[0025] According to another feature of the present invention, the cover has an inner surface provided with at least one deflector interposed between the water discharge orifice and said at least one valve, and the deflector is intended to block the injected water passing through the water discharge orifice and directed towards said at least one valve.

[0026] According to another feature of the present invention, the deflector is formed by ribs extending from the inner surface of the cover towards the vertical wall of the tray.

[0027] According to another feature of the present invention, the vertical wall has two valves, and the cover simultaneously covers two valves, for example, a "PRD" valve and a "NITTO" valve.

[0028] According to another feature of the present invention, at least one deflector is interposed between the water discharge orifice and each of the two valves.

[0029] According to another feature of the present invention, the cover has one deflector interposed between the water discharge orifice and each of the two valves. This deflector, in particular, makes it possible to prevent the intrusion of the injected water towards the valve under pressure.

[0030] Another feature of the present invention is that the cover is made of a plastic material.

[0031] Another feature of the present invention is that the cover is integrally made by molding. The cover is, for example, made of plastic.

[0032] According to another feature of the present invention, the vertical wall is made of an outer shell having an outer surface and an inner partition separated by a void, and the cover is fixed to the vertical wall by nuts fixed to the outer shell and threaded rods that penetrate the void without passing through the inner partition.

[0033] According to another feature of the present invention, the vertical wall of the tray is provided with two vertical support surfaces that face each other and project perpendicular to the vertical wall, a cover is housed between the vertical support surfaces, and the cover has elastically flexible free-end tabs that allow the cover to be held between the two support surfaces by tightening. This feature allows the cover to be held in place while the worker fastens it, taking into account the manufacturing tolerances of the parts.

[0034] Other features and advantages of the present invention will become apparent from the following detailed description, and refer to the accompanying drawings for understanding the description. [Brief explanation of the drawing]

[0035] [Figure 1] This is a schematic rear view of the vehicle chassis, showing the wheels attached and the traction battery mounted on top.

[0036] [Figure 2] Figure 1 is a perspective view of a traction battery that can be mounted on the vehicle shown, and the traction battery may be fitted with a cover manufactured according to the teachings of the present invention.

[0037] [Figure 3] This is a cross-sectional view along section 3-3 of [Figure 4], showing a valve mounted on the rear vertical wall of the traction battery.

[0038] [Figure 4] Figure 1 is a schematic side view showing a traction battery manufactured according to the teachings of the present invention, mounted on the vehicle shown.

[0039] [Figure 5] This is a vertical cross-sectional perspective view showing the vertical rear wall of the battery with the valve protective cover attached.

[0040] [Figure 6] Figure 4 is a cross-sectional view along section 6-6, showing the inner surface of a cover manufactured according to the teachings of the present invention and the valve protected by the cover.

[0041] [Figure 7] This is a front view of the rear vertical wall of a traction battery with a cover attached according to the teachings of the present invention.

[0042] [Figure 8] This is a cross-sectional view along section 8-8 of [Figure 7], showing the mounting means for screwing the cover to the rear vertical wall of the traction battery. [Modes for carrying out the invention]

[0043] Detailed description of the invention In the remainder of the specification, elements having the same structure or similar function are indicated by the same reference number.

[0044] The remainder of this specification will adopt, without limitation, the following:

[0045] - The longitudinal direction "L" is oriented in the direction of travel of the vehicle and directed from the front to the rear of the vehicle.

[0046] - A vertical "V" oriented perpendicular to the road the vehicle is traveling on, with the direction pointing upwards from the bottom, closest to the road.

[0047] - A transverse direction "T" that is perpendicular to the longitudinal and vertical directions and oriented from left to right.

[0048] A schematic diagram of automobile 10 viewed from the rear is shown in [Figure 1]. This is an electric vehicle or This is a vehicle 10 equipped with at least one electric traction motor (not shown), such as a hybrid vehicle that also has an internal combustion engine.

[0049] The vehicle 10 comprises a chassis 12 connected to four wheels 14 by an articulated suspension system 16, two of which are shown in [Figure 1].

[0050] The chassis 12 extends almost horizontally. The chassis 12 is equipped with a crossbar 18. A traction battery 20 for the vehicle, which supplies power to an electric traction motor, is designed to be fixed beneath the crossbar 18 by projections 82. A projection 83 of the traction battery 20 is fixed directly to the chassis.

[0051] As shown in [Figure 2], the traction battery 20 includes a tray 22. It generally has the form of a parallelepiped and seals and encloses an internal space 24 that houses battery cells (not shown). This internal space 24 is partitioned by an upper horizontal wall 26, a lower horizontal wall 28, a rear vertical wall 30, a front vertical wall 32, a left lateral vertical wall 34, and a right lateral vertical wall 36.

[0052] The walls of tray 22 are made of a metal material such as aluminum.

[0053] As described in the preamble, the traction battery 20 is equipped with at least one valve 38, 40, as shown in Figure 3. These are located in associated orifices 42, 44 that penetrate one of the vertical walls of the tray 22. At least one of these valves 38, 40 connects the internal space 24 of the tray 22 to the outside.

[0054] As a non-limiting example, at least one of the valves 38, 40 is located on the rear vertical wall 30 of the tray 22.

[0055] As a non-limiting example, tray 22 includes two valves 38, 40 positioned close to each other within the same vertical wall 30. The two valves 38, 40 are positioned at approximately the same height on the rear vertical wall 30.

[0056] Each valve 38, 40 is seated on the corresponding vertical wall 30, as shown by the solid line in [Figure 3]. The closed position is in contact with the seat, and as shown by the dashed line in [Figure 3], it is lifted outwards from the seat. It includes a flap 46 that is mounted to move between an open position and an open position that opens the associated orifices 42, 44. An annular seal 48 is interposed between the seat 47 and the flap 46, allowing the associated orifices 42, 44 to be sealed when the flap 46 is in its closed position. This seal 48 is made of an elastomer material.

[0057] As shown in [Figure 4], the rear wall 30 of the tray 22 of the traction battery 20 is generally The rear wall 30 is positioned at a distance from adjacent components 50 of the vehicle, thereby ensuring a free gap 52 between the adjacent components 50 and the rear wall 30. This free gap 52 is open toward the bottom of the vehicle. As a result, when the vehicle is cleaned using a high-pressure washer, the rear wall 30, more specifically the valves 38 and 40, are exposed to the high-pressure water jet.

[0058] When high-pressure water is directed towards the seals 48 of valves 38 and 40 along a direction "F" that is inclined with respect to the longitudinal direction, in the case of the associated vertical wall 30, the water is found to elastically deform the seals 48. Subsequently, the seals 48 can no longer perform their sealing function, allowing water to penetrate into the space 24 inside the tray 22.

[0059] To solve this problem, the present invention proposes to provide a protective cover 54 that is fixed to the outer surface 56 of the vertical wall 30 of the tray 22 and covers at least one of the valves 38, 40.

[0060] The cover 54 is simply secured to the tray 22. Furthermore, the cover 54 only contacts the tray 22. This means that the cover 54 can be attached to the tray 22 before the traction battery 20, with the cover 54 thus fitted, is mounted under the chassis 12.

[0061] In particular, the cover 54 is fixed only to the rear vertical wall 30 of the tray 22.

[0062] Cover 54 covers both valves 38 and 40 simultaneously.

[0063] In modified versions of the present invention not shown, each valve 38, 40 is protected by such individual covers.

[0064] The cover 54 extends within a main plane "P" which is substantially parallel to the main plane of the vertical wall 30 in which each valve 38, 40 is located. The cover 54 extends in the associated vertical plane as shown in [Figure 5]. The vertical wall 30 has a concave shape that, in cooperation with the vertical wall 30, defines a cavity 58 surrounding the valves 38 and 40. In particular, this cavity 58 allows the valves 38 and 40 to open without interference. It is sufficient that fluid exchange between the inner space 24 and the outside of the tray 22 is possible via the valves 38 and 40.

[0065] The cover 54 includes a main plate 60 extending within a plane "P" substantially parallel to the rear vertical wall 30. This plate 60 is positioned longitudinally at a distance from the valves 38 and 40, allowing for the definition of the cavity 58.

[0066] The cover 54 has at least one lower rim 62, the free lateral edge 63 of which is in contact with the outer surface 56 of the vertical wall 30 of the tray 22 below the valves 38, 40. The lower rim 62 extends in a substantially horizontal plane perpendicular to the vertical wall 30. The rim 62 extends, for example, from the substantially horizontal lower edge of the main plate 60 toward the rear vertical wall 30.

[0067] The lower rim 62 is designed to block the spray of water directed directly from the underside of the vehicle to the at least one of the valves 38, 40.

[0068] The cover 54 is not watertightly fixed to the rear vertical wall 30 of the tray 22 because it needs to allow fluid exchange between the internal space 24 of the tray 22 and the external atmosphere. As a result, water is still easily permeated into the cavity 58 separated by the cover 54 and the vertical rear wall 30. To allow water to be discharged to the outside of the cavity 58 by gravity, the lower rim 62 has a water discharge orifice, as shown in particular in [Figure 6]. It is equipped with S65.

[0069] The water discharge orifice 65 is formed here by a notch created on the free edge of the lower rim 62.

[0070] The cover 54 may also have an upper rim 64 and a lateral rim 66. However, these rims are present only in areas where a high-pressure jet of water discharged from the underside of the vehicle can reach the valves 38, 40 via the upper or side of the cover 54 positioned on the tray 22.

[0071] The presence of the lower rim 62 and main plate 60 of the cover 54 significantly reduces the risk of high-pressure water jets directly impacting the valves 38 and 40, but the risk of water jets directly entering the cavity 58 by passing through the discharge orifice 65 still exists.

[0072] To fully protect the valves 38, 40, the cover 54 has an inner surface 68 equipped with at least one deflector 70 interposed between the discharge orifice 65 and the at least one valve 38, 40. The deflector 70 is designed to block the jet of water that passes through the discharge orifice 65 and is directed toward the at least one valve 38, 40. For this purpose, the at least one deflector 70 is interposed between the discharge orifice 65 and each of the two valves 38, 40.

[0073] Here, the cover 54 includes a single deflector 70 that protects both valves 38 and 40 simultaneously. The deflector 70 is interposed between the discharge orifice 65 and each of the two valves 38 and 40.

[0074] More specifically, the deflector 70 extends from the inner surface 68 of the main plate 60 of the cover 54 toward the rear vertical wall 30. The lateral edge 71 of the free end of the deflector 70 is in substantial contact with the rear vertical wall 30.

[0075] The deflector 70 extends upward parallel to the lower rim 62.

[0076] The cover 54 is made of a rigid plastic material.

[0077] The cover 54 is preferably manufactured as a single unit. The cover 54 is manufactured as a single unit, for example, by molding.

[0078] The deflector 70 is formed here by ribs extending from the inner surface 68 of the cover 54 toward the rear vertical wall 30 of the tray 22.

[0079] To prevent water jets from entering through the unsealed gap between the free edge 63 of the lower rim 62 of the cover 54 and the vertical rear wall 30, two lateral protective strips 72 are welded to the vertical rear wall 30 at a vertical distance below each valve 38, 40 and below the cover 54. The two protective bars 72 are laterally separated from each other. As shown in Figures 6 and 7, the lateral gap between the two bars 72 extends substantially along the discharge orifice 65.

[0080] The cover 54 can be fixed to the rear vertical wall 30 by any known method, such as by screwing, gluing, or elastic interlocking.

[0081] In the embodiment shown in [Figure 8], the cover 54 is screwed to the vertical rear wall 30.

[0082] The vertical wall 30 is formed by an outer shell 30A including an outer surface 58 and an inner partition wall 30B parallel to the outer shell 30A. The inner partition wall 30B and the outer shell 30A are separated by a gap 30C. Two fixed nuts 74 are fixed to corresponding holes in the outer shell 30A. Threaded rods 76 are screwed into each fixed nut 74 and pass through the gap 30C but not through the inner partition wall 30B. The cover 54 has holes 78 through which each threaded rod 76 passes. The through holes 78 are located at the same height vertically between the two valves 38, 40. Then, loose nuts 80 are screwed onto each threaded rod 76 to tighten and secure the cover 54 between the fixed nuts 74 and the loose nuts 80. To facilitate insertion of the threaded rods 76 into the through holes 78, they are surrounded by grooves on the inner surface 68 of the cover 54.

[0083] As shown in [Figure 7], the valves 38 and 40 are generally positioned between two projections 82. The projections 82 extend longitudinally and protrude from the outer surface 58 of the rear vertical wall 30. Each projection 82 has a parallelepiped shape. Thus, each projection 82 has a longitudinal vertical support surface 84 facing the other projection 82. Thus, the two support surfaces 84 face each other laterally on both sides of the cover 54. Furthermore, each projection has a horizontal lower surface 86.

[0084] To facilitate the attachment of the cover 54 to the rear vertical wall 30 of the tray 22, the cover 54 is provided with an elastically flexible tab 88 on one of its lateral ends, which is elastically clamped against a support surface 84, while the other rigid lateral end 90 of the cover 54 abuts against the opposite support surface 84. The elastic deformation of the elastic tab 88 tightens the cover 54 between the two support surfaces 84, allowing the cover 54 to be held in place while the operator secures it to the rear vertical wall 30. Furthermore, the elastic tab 88 allows the cover 54 to be automatically positioned laterally centered between the two protrusions 82.

[0085] To facilitate vertical positioning of the cover 54, the cover is provided with two positioning surfaces 92 intended to abut vertically upward against the lower surface 86 of each projection 82.

[0086] During installation, the cover 54 is positioned between the two projections 82, at a distance from the rear vertical wall 30. The cover 54 is then positioned so that its positioning surface 92 abuts against the lower surface 86 of the projections 82. The cover 54 is then moved forward longitudinally so that a threaded rod 76 passes through the associated hole 78 in the cover 54. The hole 78 has a laterally elongated rectangular shape so that an elastic tab 88 can position the cover 54 laterally centered between the two projections 82. The cover 54 is then secured by screwing in a loose nut 80.

[0087] Advantageously, to facilitate the operator's work, the cover 54 can be attached to or removed from the vertical wall 30 of the tray 22 when the traction battery 20 is mounted to the chassis 12.

[0088] The cover 54, positioned in this manner, advantageously prevents high-pressure water from directly reaching the valves 38 and 40. This prevents accidental damage to the traction battery 20 during vehicle cleaning.

Claims

1. Automotive traction battery (20), - A tray (22) for housing battery cells, - At least one valve (38, 40) is located on the vertical wall (30) of the tray (22), - A protective cover (54) is fixed to the outer surface (58) of the vertical wall (30) and covers at least one valve (38, 40), Equipped with, The cover (54) comprises at least one lower rim (62), the free edge (63) of the lower rim (62) in contact with the outer surface (58) of the vertical wall (30), the lower rim (62) is intended to block the water jet directed toward at least one valve (38, 40), and the lower rim (62) comprises a discharge orifice (65). A traction battery (20) for automobiles, characterized by the following features.

2. The traction battery (20) according to claim 1, characterized in that the cover (54) has an inner surface (68) equipped with at least one deflector (70) interposed between the water discharge orifice (65) and the at least one valve (38, 40), wherein the deflector (70) is intended to block the water jets that pass through the water discharge orifice (65) and are directed toward the at least one valve (38, 40).

3. The traction battery (20) according to claim 2, characterized in that the deflector (70) is formed by ribs extending from the inner surface (68) of the cover (54) in the direction of the vertical wall (30) of the tray (22).

4. A traction battery (20) according to any one of claims 1 to 3, characterized in that the vertical wall (30) comprises two valves (38, 40), and the cover (54) covers both valves (38, 40) simultaneously.

5. A traction battery (20) according to claim 4, which is adopted in combination with any one of claim 2 or 3, characterized in that at least one deflector (70) is interposed between the water discharge orifice (65) and each of the two valves (38, 40).

6. The traction battery (20) according to any one of claims 1 to 5, characterized in that the cover (54) is made of a plastic material.

7. The traction battery (20) according to claim 6, characterized in that the cover (54) is integrally manufactured by molding.

8. The traction battery (20) according to any one of claims 1 to 7, characterized in that the vertical wall (30) is composed of an outer shell (30A) having an outer surface (58) and an inner partition wall (30B) separated by a gap (30C), and the cover (54) is fixed to the vertical wall (30) by a nut (74) fixed inside the outer shell (30A) and a threaded rod (76) that penetrates into the gap (30C) without passing through the inner partition wall (30B).

9. The traction battery (20) according to any one of claims 1 to 8, characterized in that the tray (22) has two vertical support surfaces (84) on its vertical wall (30) that face each other and project perpendicular to the vertical wall (30), the cover (54) is housed between the vertical support surfaces (84), and the cover (54) has a free end lug (88) that has elastic flexibility to allow the cover (54) to be held between the two support surfaces (84) by tightening.

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