BATTERY PACK DRAINAGE ARRANGEMENT

Abstract

A battery pack drain assembly comprises a drain housing with an annular outer wall and an annular inner wall, an annular channel defined between the outer and inner walls, and a primary drain valve located at least partially within the inner wall. The primary drain valve is configured to open when the fluid in the drain housing reaches the top of the inner wall.

Description

INTRODUCTION

[0001] The present invention relates to a battery pack drain arrangement for a vehicle, of the type essentially known from CN 1 16 526 089 A.

[0002] Further prior art can be found in US 2022 / 0 042 613 A1.

[0003] Battery packs used in vehicles may include a drain valve that allows fluid to be drained from the battery. A smart and efficient drain valve is desirable. SUMMARY

[0004] According to the invention, a battery pack drain assembly is presented which is characterized by the features of claim 1 or those of claim 6.

[0005] The battery pack drain assembly includes a drain housing having an annular outer wall and an annular inner wall. An annular channel is disposed between the outer wall and the inner wall. A primary drain valve is disposed at least partially within the inner wall. The primary drain valve is configured to open when the fluid in the drain housing reaches an upper portion of the inner wall.

[0006] The battery pack drain assembly includes a secondary drain valve located on the outer wall.

[0007] Additionally or alternatively, the drain housing comprises a lower housing comprising the inner wall and the outer wall, and an upper housing mounted on the lower housing to form an enclosed space therein. Additionally, the battery pack drain assembly comprises a secondary drain valve disposed on the outer wall, the upper housing including a secondary drain recess above the secondary drain valve.

[0008] In addition to one or more of the features described herein, the battery pack vent assembly includes a shoulder extending from an upper portion of the inner wall, the shoulder and the inner wall defining a valve seat.

[0009] In addition to one or more of the features described herein, an opening is formed in the shoulder through which the primary vent valve passes.

[0010] In addition to one or more of the features described herein, the secondary drain valve is a check valve.

[0011] In addition to one or more of the features described herein, the secondary drain valve is a one-way valve.

[0012] In addition to one or more of the features described herein, the secondary drain valve is a flap valve.

[0013] In addition to one or more of the features described herein, the secondary drain valve is formed from a diaphragm that, when the secondary drain valve is closed, allows water vapor to pass through while preventing the flow of liquid.

[0014] In addition to one or more of the features described herein, the upper housing is secured to the lower housing with a fastener.

[0015] In addition to one or more of the features described herein, the upper housing is removably attached to the lower housing by a fastener.

[0016] In addition to one or more of the features described here, the inner wall is higher than the outer wall.

[0017] In addition to one or more of the features described herein, the primary drain valve includes a sensor that detects when the liquid reaches the top of the inner wall.

[0018] Further described is a vehicle comprising a battery pack assembly with a battery pack housing having a battery pack housing base. A plurality of battery cells are arranged in the battery pack housing. The vehicle includes a cooling system for cooling the battery cells. A battery pack drain assembly is embedded in the battery pack housing base. The battery pack drain assembly includes a lower housing having an annular outer wall, an annular inner wall, and a shoulder extending inward from a top surface of the inner wall. An upper housing is mounted on the lower housing, forming an enclosed space. An annular channel is arranged between the outer wall and the inner wall. A primary drain valve is arranged through an opening in the shoulder and at least partially within the inner wall. A secondary drain valve, which is a one-way valve, is arranged on the outer wall.The primary drain valve is designed to open when the fluid in the drain housing reaches the shoulder.

[0019] The foregoing features and advantages, as well as other features and advantages of the disclosure, will be readily apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further features, advantages and details are included by way of example only in the following detailed description, which refers to the drawings in which: Fig. 1 is a left side view of a vehicle with a battery pack assembly including a battery pack drain assembly according to one example; Fig. 2 is a schematic view of a battery pack assembly with a battery pack drain assembly according to an example; Fig. 3 is a top perspective view of a battery pack drain assembly according to an example; Fig. 4. a cross-sectional view of the Fig. 3 shown battery pack drain arrangement at 4-4; Fig. 5 is a top perspective view of a lower housing and a main drain valve according to an example; Fig. 6 a cross-sectional view of the Fig. 5 and the main drain valve at 6-6; Fig. 7 is a bottom view of an upper housing and secondary bleed valves according to an example. DETAILED DESCRIPTION

[0021] The following description is merely exemplary. It should be understood that like or corresponding parts and features are designated by corresponding reference numerals throughout the drawings.

[0022] A vehicle 10 according to an example is in Fig. 1. The vehicle 10 includes a body 12 supported on a plurality of wheels 16. One or more of the plurality of wheels 16 is / are steerable. The body 12 partially defines a passenger compartment 20 with seats 23 disposed behind an instrument panel 26. A steering controller 30 is disposed between the seats 23 and an instrument panel 26. The steering controller 30 is actuated to control the orientation of the steerable wheel(s) 16.

[0023] The vehicle 10 includes an electric motor 34 connected to a transmission 36 that drives one or more of the plurality of wheels 16. A rechargeable energy storage system 38 is disposed within the body 12 and supplies power to the electric motor 34. While specific locations in Fig. 1, these locations are only examples and the locations of these structures may vary.

[0024] A battery pack assembly 100 according to an example is shown in Fig. 2. According to one or more embodiments, the battery pack assembly 100 may be part of the rechargeable energy storage system 38 shown in Fig. 1. The battery pack assembly 100 may include a battery module 110 having a plurality of battery cells 115. According to one or more embodiments, the battery module 110 is arranged in a battery pack housing 120. The battery module 110 and the battery pack housing 120 may together be considered a battery pack assembly. While Fig. While FIG. 2 shows a single battery module 110 within the battery pack housing 120, multiple battery modules 110 may be arranged within the battery pack housing 120. The battery cells 115 may be pouch cells, prismatic cells, cylindrical cells, or other battery cells known in the art. According to one or more embodiments, the battery pack assembly 100 includes a cooling system 130 for dissipating heat from the battery module 110.

[0025] According to one or more embodiments, the battery pack housing 120 may include a battery pack housing base 121. According to one or more embodiments, a battery pack drain assembly 200 is disposed on the battery pack housing base 121. The battery pack drain assembly 200 is disposed in the lowermost portion of the battery pack housing base 121 such that fluid can flow to the battery pack drain assembly 200 by gravity.

[0026] Fig. 3 shows a battery pack drain assembly 200 according to one or more embodiments, and Fig. Figure 4 shows a cross-sectional view of the battery pack drain assembly 200 at 4-4 in Fig. 3. Fig. 5 shows a lower housing 220 and a primary drain valve 240 according to one or more embodiments, and Fig. Figure 6 shows a cross-sectional view of the lower housing 220 and the primary drain valve 240 at 6-6 in Fig. 5. Fig. 7 shows an upper housing 210 and secondary vent valves 230 according to one or more embodiments.

[0027] According to one or more embodiments, the battery pack drain assembly 200 includes an upper housing 210, a lower housing 220, a plurality of secondary drain valves 230, a primary drain valve 240, and a plurality of fasteners 250. While the battery pack drain assembly 200 is illustrated with four secondary drain valves 230 and four fasteners 250, the present disclosure is not so limited. For example, there may be one secondary drain valve 230 and / or one fastener 250, or any plurality of secondary drain valves 230 and / or fasteners 250.

[0028] According to one or more embodiments, the upper housing 210 may include a main body 211 in the shape of a circular dome. In one or more embodiments, the upper housing 210 may have a different shape, such as a cylindrical shape or a rectangular box shape. A plurality of fastener recesses 212 may be formed on the periphery of the main body 211 and structured to allow fasteners 250 to pass therethrough. According to one or more embodiments, the fastener recesses 212 may have a curved surface.According to one or more embodiments, each of the fastener recesses 212 may include an opening through which a portion of the fastener 250 may pass, as well as an abutment surface for the head of the fastener 250 to create a downward force on the upper housing 210 toward the lower housing 220. A plurality of secondary vent recesses 213 may be formed on a periphery of the main body 211. Each of the secondary vent recesses 213 may have a curved surface. According to one or more embodiments, the fastener recesses 212 may be circumferentially offset from the secondary vent recesses 213. A lower surface 214 of each of the secondary vent recesses 213 may abut an upper surface of an inner portion 233 of the secondary vent valve 230 to form a seal when the secondary vent valve 230 is closed.An inner dome structure 215 may be formed at a central portion of the main body 211 of the upper case 210.

[0029] According to one or more embodiments, the lower housing 220 may include an inner wall 221, an outer wall 223, and a bottom 224 extending between the inner wall 221 and the outer wall 223. The inner wall 221 and the outer wall 223 may be annular structures that extend continuously around a central axis A of the lower housing 220. The inner wall 221, the bottom 224, and the outer wall 223 may define an annular channel 300 in a space between the inner wall 221 and the outer wall 223. A valve seat 229 may be formed in a central portion of the lower housing 220. The valve seat 229 includes the inner wall 221 and a shoulder 222 extending from an upper portion thereof. The shoulder 222 extends radially inward toward the central axis A of the lower housing 220.The shoulder 222 may include a primary vent valve opening 225 in its radially central portion, within which the primary vent valve 240 may be received. According to one or more embodiments, the inner wall 221 may be taller than the outer wall 223. The outer wall 223 may include a plurality of secondary vent valve mounting surfaces 226 recessed downwardly from the remainder of the outer wall 223. A bottom surface of an outer portion 231 of the secondary vent valve 230 may be secured to each of the secondary vent valve mounting surfaces 226 by bonding, bonding, or another attachment method. Alternatively, the secondary vent valve 230 may be formed as a unitary structure with the lower housing 220. A plurality of circumferentially offset mounting posts 227 may extend upwardly from the outer wall 223.An opening 228 may be formed in each of the plurality of mounting posts 227. A portion of the fastener 250 may be inserted into the opening 228. For example, if the fastener 250 is a screw, an inner surface of the opening 228 may be threaded, and the threaded portion of the screw may be inserted into the opening 228 to secure the screw in the opening 228. The upper housing 210 may be fitted over the lower housing 220 to form an enclosed space therein, with the fastener 250 connecting the upper housing 210 to the lower housing 220.

[0030] According to one or more embodiments, the battery pack drain assembly 200 may be at least partially embedded in the battery pack housing bottom 121 of the battery pack housing 120, as shown in Fig. 2. According to one or more embodiments, the lower housing 220 is partially embedded in the battery pack housing base 121 such that the top of the secondary drain valve 230 can be at the same height as or lower than the surrounding battery pack housing base 121. In this way, the liquid on the battery pack housing base 121 can flow into the battery pack drain assembly 200 by gravity. The upper housing 210 can be mounted on the lower housing 220 and together form a drain housing.

[0031] The secondary drain valves 230 may be check valves that open when fluid (e.g., water) is outside the battery pack drain assembly 200, allowing the fluid to flow into the annular channel 300. According to one or more embodiments, the secondary drain valves 230 may be one-way valves. The secondary drain valves 230 may, for example, be flap valves, as shown in Fig. 3, Fig. 4 and Fig. 7. According to one or more embodiments, the secondary vent valves 230 may be silicone flap valves. According to one or more embodiments, each of the secondary vent valves 230 may be formed from a membrane that, when closed, still allows water vapor to pass through while preventing the passage of liquid. Each of the secondary vent valves 230 may include a main body 232 extending between an outer portion 231, which may be attached to the secondary vent valve attachment surface 226, and an inner portion 233, which may abut a bottom surface 214 of the secondary vent recess 213, which serves as a valve seat. As shown in Fig.As shown in Figure 4, the main body 232 of the secondary drain valve 230 may deform downward when the fluid reaches a top surface of the main body 232 to open the secondary drain valve 230. While the secondary drain valves 230 are illustrated as flapper valves, the secondary drain valves 230 may instead be an umbrella valve, a mushroom valve, a flapper check valve, a ball check valve, a diaphragm check valve, a lift check valve, a swing check valve, an in-line check valve, a duckbill valve, or other check valve.

[0032] The primary drain valve 240 is disposed within the primary drain valve opening 225. The primary drain valve 240 may include a main body 241 and a sealing surface 243 that engages a lower surface of the shoulder 222 to form a seal when the primary drain valve 240 is closed. Upon the presence of fluid above the shoulder 222, the primary drain valve 240 opens to allow fluid to drain from the battery pack drain assembly 200. The primary drain valve 240 may include a sensor that detects the presence of fluid above the shoulder 222 to open the primary drain valve 240 and close the primary drain valve 240 when the sensor no longer detects fluid. The primary drain valve 240 may be an absorption drain valve or other valve known in the art capable of draining fluid from the battery pack drain assembly 200.

[0033] According to one or more embodiments, the plurality of fasteners 250 secure the upper housing 210 to the lower housing 220. The fasteners 250 may be screws that extend through the mounting recesses 212 of the upper housing 210 into the openings 228 in the mounting posts 227 of the lower housing 220. The fasteners 250 may be removable so that the upper housing 210 may be removed from the lower housing 220 to clean the annular channel 300 of liquid, dust, or debris. While the fasteners 250 are illustrated as screws by way of example, according to one or more embodiments, the fasteners may also be bolts, rivets, anchors, adhesives, or any other fastening element known in the art. According to one or more embodiments, the upper housing 210 may be bonded to the lower housing 220.According to one or more embodiments, the upper housing 210 and the lower housing 220 may be secured by a press fit.

[0034] A liquid (e.g., water) may enter the battery pack housing 120 of the battery pack assembly 100 during use. For example, condensation may drip onto the battery pack housing base 121 (e.g., from a cooling system 130). In such a case, the liquid may flow slowly and / or intermittently to the battery pack housing base 121. Such an event is referred to as an intermittent liquid event. Another example is a liquid leak in the battery pack assembly 100 or in an external system that results in liquid entering the battery pack housing 120. Such an event is referred to as a high liquid flow event. Since the battery pack housing 120 may include high-voltage battery cells 115, the accumulation of liquid in the battery pack housing 120 is undesirable. The drain valve is therefore located on the battery pack housing base 121 to drain the liquid.A drain valve that opens each time an intermittent fluid event occurs or when a high flow rate fluid event occurs may drain the fluid from the battery pack housing 120, but there is a risk of fluid entering the battery pack housing 120 from below each time the drain valve is opened.

[0035] Therefore, as described herein, one or more embodiments of the battery pack drain assembly 200 may reduce the frequency of opening the primary drain valve 240 while maintaining the ability to drain the fluid from the battery pack enclosure 120 as desired. Furthermore, in one or more embodiments, fluid entering below the primary drain valve 240 may be prevented from entering the battery pack enclosure 120 or any of the battery cells 115 or electrical components therein.

[0036] As described, the top of the secondary drain valve 230 may be level with or lower than the battery pack housing base 121 surrounding the battery pack drain assembly 200. This allows fluid on the battery pack housing base 121 to open the secondary drain valve 230 and flow into the annular channel 300 of the lower housing 220. The secondary drain valve 230 may close once most or all of the fluid on the battery pack housing base 121 has flowed into the battery pack drain assembly 200. During intermittent fluid events, the annular channel 300 receives the fluid, which may be prevented from splashing back into the battery pack housing 120 by the closed secondary drain valve 230. The primary drain valve 240 must not open until the fluid fills the annular channel 300 to a level at or above the shoulder 222 of the valve seat 229.Once the fluid reaches the level at or above the shoulder 222 of the valve seat 229, the fluid opens the primary drain valve 240 and drains from the battery pack drain assembly 200. During a high-flow velocity fluid event, the fluid may flow onto the battery pack housing base 121 at a relatively high flow rate. Due to the relatively high flow rate, the fluid opens the secondary drain valve(s) 230 and fills the annular channel 300 to the shoulder 222 and opens the primary drain valve 240 to flow out of the battery pack drain assembly 200. Thus, during intermittent fluid events, the frequency of opening the primary drain valve 240 may be reduced because the fluid may be stored in the annular channel 300 instead of opening the primary drain valve 240.During a high flow velocity fluid event, the annular channel 300 may fill relatively quickly to reach the height of the shoulder 222 of the valve seat 229 and open the primary drain valve 240 so that the battery pack drain assembly 200 may be able to effectively drain fluid from the battery pack housing 120 during a high flow velocity fluid event.

[0037] According to one or more embodiments, the battery pack drain assembly 200 can effectively drain the battery pack housing 120 during a high-flow fluid event and / or select intermittent fluid events as desired. According to one or more embodiments, by reducing the frequency of opening the primary drain valve 240 during intermittent fluid events, the risk of fluid or foreign matter entering the battery pack drain assembly 200 through an open primary drain valve 240 can be reduced. According to one or more embodiments, the secondary drain valve 230, which can be a check valve or a one-way valve, prevents the fluid from entering the battery pack housing 120 even if fluid enters the battery pack drain assembly 200 through an open primary drain valve 240.

Claims

[1] A battery pack drain assembly (200) comprising: a drain housing (210, 220) comprising an annular outer wall (223) and an annular inner wall (221); an annular channel (300) defined between the outer wall (223) and the inner wall (221); and a primary drain valve (240) disposed at least partially within the inner wall (221), wherein the primary drain valve (240) is configured to open when the liquid in the drain housing (210, 220) reaches an upper portion of the inner wall (221); characterized by , that the battery pack drain assembly (200) further comprises a secondary drain valve (230) disposed on the outer wall (223). [2] The battery pack drain assembly (200) of claim 1, further comprising: a shoulder (222) extending from a top of the inner wall (221), the shoulder (222) and the inner wall (221) forming a valve seat. [3] The battery pack drain assembly (200) of claim 2, wherein an opening (225) is formed in the shoulder (222) and the primary drain valve (240) extends through the opening (225). [4] The battery pack drain assembly (200) of claim 1, wherein the secondary drain valve (230) is a one-way valve. [5] The battery pack drain assembly (200) of claim 1, wherein the secondary drain valve (230) is formed from a membrane that, when the secondary drain valve (230) is closed, allows water vapor to pass through while preventing the passage of liquid. [6] A battery pack drain assembly (200) comprising: a drain housing (210, 220) comprising an annular outer wall (223) and an annular inner wall (221); an annular channel (300) defined between the outer wall (223) and the inner wall (221); and a primary drain valve (240) disposed at least partially within the inner wall (221), wherein the primary drain valve (240) is configured to open when the liquid in the drain housing (210, 220) reaches an upper portion of the inner wall (221); characterized by , that the drain housing (210, 220) comprises a lower housing (220) comprising the inner wall (221) and the outer wall (223), and an upper housing (210) mounted on the lower housing (220) to form a closed space therein; wherein the battery pack drain assembly further comprises a secondary drain valve (230) disposed on the outer wall (223), wherein the upper housing (210) comprises a secondary drain recess (213) above the secondary drain valve (230). [7] The battery pack drain assembly (200) of claim 6, wherein the upper housing (210) is removably attached to the lower housing (220) by a fastener (250). [8] The battery pack drain assembly (200) of claim 1 or 6, wherein the inner wall (221) is higher than the outer wall (223).

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