Battery unit

Abstract

Battery unit (10), comprising: a battery pack module (11) comprising a plurality of individual cells (41); a control circuit board (12) which has a control section which controls charging and discharging in the battery pack module (11); a storage housing (16) in which the battery pack module (11) and the control circuit board (12) are accommodated; a base (14) of the storage housing (16), wherein the base (14) has a base plate (21) where the battery pack module (11) is installed, and where a wall section (22) rises from the base plate (21) such that it surrounds the battery pack module (11); and a submersion sensor (122) which is electrically connected to the control section and which detects the submersion of the battery unit (10); wherein the control circuit board (12) is arranged in a position which is located on a side of the battery pack module (11) opposite the base plate (21), and which is separated from the base plate (21) by a distance which is greater than a distance from the base plate (21) to an upper wall end part of the wall section (22); and wherein the submersion sensor (122) is arranged in a position which is closer to the base plate (21) than to the upper wall end part of the wall section (22), which is located in a space within the housing which is surrounded by the wall section (22), where: the wall section (22) has a collar section (23) which is designed to be continuous in such a way that it surrounds the battery pack module (11), and which has an upper end part as the upper wall end part, and which has a plurality of support columns (24) which are higher than the upper wall end part, and the control circuit board (12) is fixed to the upper end part of the support columns (24).

Description

BACKGROUND OF THE INVENTION Technical field of the invention

[0001] The present invention relates to a battery unit formed by having a battery pack module, and which is installed in vehicles, such as a car. DESCRIPTION OF THE STATE OF THE ART

[0002] Traditionally, a technology is known which forms a battery unit by providing a battery pack module that has a plurality of individual cells uniformly together with a control circuit board, etc. (for example, with reference to the published Japanese patent application with publication number JP 2011 - 216 401 A).

[0003] Furthermore, the installation of such a battery unit in vehicles is proposed.

[0004] In a setup where the battery unit is installed in the vehicle, the submersion of the battery unit is detected by a submersion sensor located in the battery unit when the vehicle is flooded with water.

[0005] In this case, control sections, such as a CPU mounted on the control circuit board, perform a procedure that suspends or interrupts the charging and discharging function of the battery pack module and the like, according to a detected result from the immersion sensor.

[0006] However, if the submersion of the battery unit is not adequately detected when the vehicle is flooded with water or drives into a puddle, various inconveniences or circumstances will occur.

[0007] For example, if water is detected by the submersion sensor, even if only a small amount of water enters the battery unit, and the water level does not rise, an incorrect detection is generated that the battery unit is in a submerged state, and functions of the battery unit, such as the charging and discharging function of the battery pack module, may be unnecessarily suspended.

[0008] On the other hand, if the water is not easily detected despite the water level actually rising – i.e., in a setup where the water is only detected by the submersion sensor just before a control section in the battery unit is submerged – it is possible that a control device of the control section is suspended before it can suspend battery charging and discharging, etc., and in this case it becomes impossible to implement a suitable countermeasure against flooding.

[0009] US Patent 6,617,973 B1 discloses a battery safe system that delivers a battery power signal to an electronic device. The safe system consists of an outer enclosure assembly containing the batteries. Power cables run from the outer enclosure assembly to the electronic device. The safe system protects the batteries and associated electronics, removes fluid from inside the outer enclosure assembly, and / or allows remote access to the status of the safe system. SUMMARY OF THE INVENTION

[0010] The present invention was made in light of the problem presented above, and its objective is to provide a battery unit which can suitably detect immersion and which can appropriately suspend battery charging and discharging, etc.

[0011] This problem is solved by the battery unit with the features of claim 1. Advantageous further developments are found in the associated dependent claims.

[0012] In a battery unit according to a first aspect, the battery unit comprises the following: a battery pack module which has a plurality of individual cells, a control circuit board which has a control section which controls charging and discharging in the battery pack module, a storage housing in which the battery pack module and the control circuit board are accommodated, a base which is designed as the storage housing which has a base plate in which the battery pack module is installed, and a wall section which rises from the base plate so that it surrounds the battery pack module, and a submersion sensor which is electrically connected to the control section and which detects the submersion of the battery unit.

[0013] The control circuit board is arranged in a position on a side of the battery pack module opposite the base plate, and is separated from the base plate by a distance greater than the distance from the base plate to an upper wall end part of the wall section.

[0014] The submersible sensor is positioned closer to the base plate than to the upper wall end of the wall section, i.e., in a space within the housing surrounded by the wall section.

[0015] According to the aforementioned setup, if the battery unit is arranged such that the base plate is on a plane, the submersion sensor is positioned lower than the upper wall end part of the wall section of the base, and the control circuit board (the control section) is positioned higher than the upper wall end part.

[0016] That is, the control circuit board (the control section), the upper wall end part of the wall section, and the submersion sensor.

[0017] Therefore, if the battery unit is installed in vehicles, for example, flooding inside the housing will not occur until the water level exceeds the wall height of the wall section in the situation where the vehicle is flooded with water and the battery unit has submerged or sunk.

[0018] Then, when the water level exceeds the wall height of the wall section, the flooding (i.e., submersion) is detected by the submersion sensor when the space inside the enclosure begins to be flooded.

[0019] Since the control circuit board is not yet flooded when the flooding begins, the control section of the control circuit board can perform necessary tasks, such as suspending the charging and discharging of the battery pack module itself, based on a detected signal from the submersion sensor, before a functional stop, etc., of the battery unit is caused by the flooding.

[0020] Furthermore, since the wall section is designed to surround the battery pack module in the base, the submersion sensor does not detect submersion to the extent that the battery unit is only slightly flooded with water or water is splashed onto the battery unit, thus suppressing an incorrect detection of submersion.

[0021] Therefore, unnecessary termination of the charging and discharging of the battery pack module, etc., is suppressed.

[0022] In a battery unit according to a second aspect, the storage housing has a cover which is attached to the base, the cover having a head plate or top plate which covers the control circuit board, and hanging walls extending from the top plate, the base and the cover being mounted or assembled in a state in which either the wall section of the base or the hanging walls of the cover are arranged inside the housing and another is arranged outside the housing, so that they overlap in a horizontal direction inside and outside.

[0023] In a battery unit according to a third aspect, the base and the cover are mounted in the state in which the wall section of the base is arranged inside the housing and the hanging walls of the cover are arranged outside the housing.

[0024] In a battery unit according to a fourth aspect, the wall section has a collar section which is designed to be continuous in such a way that it surrounds the battery pack module, and which has an upper end part as the upper wall end part, and which has a plurality of support columns which are higher than the upper wall end part, and wherein the control circuit board is fixed to the upper end part of the support columns.

[0025] In a battery unit according to a fifth aspect, the battery pack module has a battery housing in which the majority of individual cells are housed, wherein the battery housing is installed on the base plate such that the battery housing is arranged in a space within the housing, and wherein a sensor attachment for attaching the submersion sensor is integrally formed on an outside of one side of the battery housing. BRIEF DESCRIPTION OF THE DRAWING

[0026] It shows / It shows: Fig. 1. A perspective view of the entire structure of a battery unit; Fig. 2 a cross-sectional view, which is drawn along a line II-II of Fig. 1 was undertaken; Fig. 3 a cross-sectional view, which is drawn along a line III-III of Fig. 2 was undertaken; Fig. 4 a perspective view showing a detailed breakdown of the main structure of the battery unit; Fig. 5 a perspective view of the battery unit in a state where a cover and a control circuit board are removed from it; Fig. 6 a perspective view of the battery unit in a state where only the cover is removed; Fig. 7 a perspective view of the construction of a base; Fig. 8A a plan view of the base; Fig. 8B a flat underside view of the base; Fig. 9 a perspective view of the cover assembly; Fig. 10 a perspective view of an entire battery pack module; Fig. 11 a perspective view of exploded or individually shown parts that form the battery pack module; Fig. 12 a perspective view of exploded representations of parts that form the battery pack module; Fig. 13 a flat view of the battery pack module; Fig. 14 a cross-sectional view, which runs along a line XIV-XIV of Fig. 13 was undertaken; Fig. 15 a cross-sectional view, which is drawn along a line XV-XV of Fig. 13 was undertaken; Fig. 16 a perspective view of a dissolved representation of an outlet channel; Fig. 17 a forming pattern or structure of metallic conductors in a second body; Fig. 18 a perspective view of the control circuit board and a structure attached to it; Fig. 19A and Fig. 19B Enlarged views of a circuit board-side connection layout; Fig. 20A and Fig. 20B Views of a retaining plate assembly; Fig. 21 a view of an electrical layout of an electrical power system; and Fig. 22 a cross-sectional view of another battery pack module structure. DETAILED DESCRIPTION OF PREFERRED EXECUTION FORMS

[0027] With reference to the drawing, an embodiment of the present invention will be described below.

[0028] In the present embodiment, a housing suitable for an electrical power supply system installed in vehicles is assumed.

[0029] The electrical power supply system controls a sequential electrical charging and discharging in an electricity collection section (power supply section) to supply electrical power to various electrical loads located in the vehicle.

[0030] The vehicle is equipped with a machine, which is an internal combustion engine, an in-vehicle ECU that controls the machine and other parts, a power generator (an alternator) which is driven by the machine and generates electricity, and an electricity collection section which is charged by the electricity generated by the power generator.

[0031] In particular, this device has a design in that it uses a lead-acid battery and a lithium-ion battery as the electricity collection section.

[0032] The present embodiment explains in detail a lithium battery unit (hereinafter referred to simply as battery unit) which functions as the lithium-ion battery.

[0033] First, the overall structure of battery unit 10 is described using the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6 explained.

[0034] Additionally, for the sake of simplicity, the following explanations assume a vertical orientation of battery unit 10 based on... Fig. 1 specified, in which the battery unit 10 is arranged on a horizontal surface.

[0035] The battery unit 10 comprises a battery pack module 11, a control circuit board 12, a retention plate 13 and a storage housing 16.

[0036] The battery pack module 11 has a plurality of individual cells.

[0037] Furthermore, the control circuit board 12 controls the charging and discharging of the battery pack module 11, etc.

[0038] Furthermore, the retaining plate 13 holds the battery pack module 11 from above.

[0039] Furthermore, the storage case 16 is made from a base 14 and a cover 15.

[0040] The battery pack module 11 and the control circuit board 12 are arranged opposite each other in a vertical direction such that the battery pack module 11 is located on the bottom and the control circuit board 12 on the top, and both are attached to the base 14.

[0041] Fig. Figure 5 shows a state in which the battery pack module 11 and the retaining plate 13 are mounted on the base 14, and Fig. Figure 6 shows a state where the control circuit board 12, compared to Fig. 5 is additionally mounted.

[0042] Then the battery unit 10, which is in Fig. As shown in Figure 1, by mounting the cover 15 from above onto the integrally mounted parts, which are in Fig. 6 are shown, created, and the battery unit 10 is created by housing the battery pack module 11 and the control circuit board 12 in the storage housing 16.

[0043] Furthermore, the battery unit 10 has a terminal block 17, which is electrically connected to the lead-acid battery and the power generator outside the unit, and a connector 18, which is electrically connected to an in-vehicle ECU.

[0044] The terminal blocks 17 and the connector 18 are arranged such that they are freestanding outside the battery unit 10, as shown in Fig. 1 shown.

[0045] The following section describes in detail the structure of each part of battery unit 10. Storage case 16

[0046] The base 14 of the storage case 16 is explained.

[0047] The base 14 is manufactured with metal, such as aluminium, and has a base plate 21 and a wall section 22 which rises from the base plate 21.

[0048] The base plate has an essentially rectangular shape, and the wall section 22 is designed such that it surrounds a peripheral part or is located near a peripheral part of the base plate 21.

[0049] The base plate 21 is a module installation section in which the battery pack module 11 is installed.

[0050] In a state where the battery pack module 11 is installed on the base plate 21, the battery pack module 11 is surrounded (enclosed) by the wall section 22.

[0051] The wall section 22 has a collar section 23, which is designed to be continuous in such a way that it surrounds the battery pack module 11, and a plurality of support columns 24 which extend upwards from the collar section 23.

[0052] In wall section 22, a significant wall height is suppressed or held down by the collar section 23, and an upper end part of the collar section 23 becomes an upper wall end part.

[0053] In the state where the base plate 21 is flat and the base 14 is installed on it, the height position of the upper wall end part of the collar section 23 becomes a limiting height for the penetration of water into the base 14.

[0054] Each support column 24 is designed such that it extends higher than the upper end part of the collar section 23 (i.e., to a side opposite the base plate side), and the battery pack module 11, the control circuit board 12 and the retaining plate 13 are fixed to the upper end parts of these support columns 24.

[0055] In this case, screw holes are formed in the upper end parts of each support column 24, and the battery pack module 11, the control circuit board 12 and the retaining plate 13 are fixed with fixing screws N in a state in which each of these components is mounted from above at the predetermined positions.

[0056] In addition, a plurality of fixing columns 25, which are different from the aforementioned support columns 24, are formed in or at the base at the point where the battery pack module 11 and the control circuit board 12 are fixed.

[0057] The fixing columns 25 are designed to rise independently from the base plate 21 to or from the wall section 22.

[0058] A heat emitter is arranged on the base 14, which radiates the heat to the outside, which is generated in the battery pack module 11 or the control circuit board 12.

[0059] More precisely, ribs 27 are designed for heat radiation as the heat emitter on a bottom surface side of the base plate 21, as shown in Fig. 8B shown.

[0060] In this case, the heat generated in the battery pack module 11 or the control circuit board 12 is conducted to the base plate 21 via the wall section 22 and radiated out of the unit through the ribs 27 of the base plate 21.

[0061] Furthermore, a heat dissipation section for power elements is designed on an upper surface side of the base plate 21 such that it faces a rear side of the control circuit board 12.

[0062] This is referred to below as element heat emitter 28.

[0063] An upper surface of the element heat emitter 28 is an opposing plate part 29, which is opposite the control circuit board 12, and on a lower surface of the opposing plate part 29 a plurality of fins or ribs 30 are formed for heat radiation.

[0064] The element heat emitter 28 is arranged such that it is opposite the fixed sections of power elements P in or on the control circuit board 12, and that the heat generated by the power elements P is directed to the opposite plate part 29 and is further radiated out of the unit through the fins 30.

[0065] The power element P is made from a semiconducting element for electrical power, and a power transistor (for example, a power MOSFET or an IGBT) as the power elements P is arranged in an electrical power path which leads to the battery pack module 11 in the battery unit 10.

[0066] The input and output of electrical power to the battery module 11 are controlled by opening or closing the power element P (ON or OFF).

[0067] Additionally, the battery unit 10 is connected to the lead-acid battery and the power generator, and the electrical power path leading to the battery pack module 11 is also an electrical power path leading to the lead-acid battery and the power generator.

[0068] Two protruding sections 23, which extend upwards, are formed in the upper surface of the base plate 21.

[0069] The upper surfaces of the protruding sections 32 are designed to be flat, and when swelling of a single cell 41 of the battery pack module 11 occurs, the upper surfaces of the protruding sections 32 become contacting or touching surfaces 33 that touch the battery pack module 11 (the swollen section of the single cell 41 on the side of the base plate).

[0070] The contacting surface 33 of the projecting section 32 is smaller than a bottom surface of the individual cell 41 (explained in more detail later) of the battery pack module 11, and touches part of the side of the bottom surface of the battery housing 42.

[0071] Additionally, flanges 34 are formed in the base plate 21 outside the wall section 22, and through holes 34a for inserting fastening elements (bolts etc.) which fix the unit are formed in the flanges 34.

[0072] On the other hand, cover 15 has a structure as shown in Fig. 9 shown.

[0073] The cover 15 is made of metal, such as aluminium, in a similar manner to the base 14, or is made of a synthetic resin material, and has a top plate 35 which covers the control circuit board 12 from above, and has hanging walls 36 which extend from the edges of the top plate 35.

[0074] The upper plate 35 has an essentially rectangular shape and the hanging walls 36 are designed such that they surround a peripheral part of the upper plate 35 or are located near a peripheral part of the upper plate 35.

[0075] A non-wall section 37 for exposing the connection block 17 and the connector 18 to the outside is formed in one of the hanging walls 36, which are arranged on the four sides of the upper plate 35.

[0076] The base 14 and the cover 15 are assembled in a state in which the wall section 22 of the base 14 is arranged inside the housing 16 and the hanging walls 36 of the cover 15 are arranged outside the housing, so that they overlap inside and outside in the horizontal direction (referring to Fig. 2 and Fig. 3).

[0077] In this case, the cover 15 is arranged in a state in which part of the floor surface of the upper plate 35 touches the upper end parts of the support columns 24 of the wall section in the base 14.

[0078] In this state, the hanging walls 36 of the cover 15 and the collar section 23 of the wall section 22 overlap inside and outside in the horizontal direction of the housing (however, with the exception of the section where the non-wall section 37 is formed in the cover 15).

[0079] Therefore, in the state where the battery unit 10 is flooded with water, the water outside the unit enters a space inside the housing 16 by flowing upwards through a gap between the wall section 22 and the hanging walls 36, thus preventing the water from immediately flowing into the space inside the housing 16.

[0080] Furthermore, even if water is poured onto the battery unit 10 in such a way that the battery unit 10 is almost flooded with water, the water will not enter the storage housing 16 if the water level does not exceed the collar section 23, which is located on an inside of an overlapping section of the housing 16, and water ingress for reasons other than the rise in water level can be suppressed. Battery pack module 11

[0081] The battery pack module 11 is explained below.

[0082] The battery pack module 11 generally comprises a plurality of (five in the present embodiment) individual cells 41, a battery housing 42 in which these individual cells 41 are housed, an insulation cover 43 which is attached to the battery housing 42, and an outlet channel 44 which overlaps the insulation cover 43 on one side opposite the battery.

[0083] A main battery section Y is formed by the plurality of individual cells 41, the battery casing 42 where the individual cells are housed in a stacked state, and the insulation cover 43. Single cell 41

[0084] Each of the five individual cells 41 is a lithium-ion battery, which has a thin cuboid shape.

[0085] As in Fig. As shown in Figure 11, an anode connection 51 and a cathode connection 52 are formed on one side of each individual cell 41.

[0086] Each of the terminals 51 and 52 is formed by electrode terminals which protrude slightly from one side of the battery.

[0087] Furthermore, in each individual cell 41 an outlet valve 53 is arranged between the anode connection 51 and the cathode connection 52.

[0088] The outlet valve 53 is a safety valve which breaks and opens when an internal pressure of the individual cell 41 becomes abnormal, and this is formed by closing a hole which opens on an end face of an outer casing of the individual cell 41, for example with a thin metallic film.

[0089] The metallic film of the outlet valve 53 breaks and the gas inside a battery, etc., is released to the outside of the battery when the internal pressure of the individual cell 14 becomes abnormal.

[0090] Therefore, the internal pressure of the cell decreases and a rupture of the individual cell itself is suppressed. Battery housing 42

[0091] The battery housing 42 is a battery storage component for arranging the five individual cells 41 in the predetermined stacked state, and it is made of a synthetic resin material which, for example, has an insulating property.

[0092] As in Fig. 11, Fig. 14 and Fig. As shown in Figure 15, the battery housing 42 has a perimeter plate 55, which is a perimeter part, and separating plates 56, which are arranged between the individual cells 41, which are stacked vertically.

[0093] In the battery housing 42, a plurality of battery storage spaces are provided for each individual cell, which are separated in a vertical direction by the partition plates 56.

[0094] The perimeter plate 55 includes a bottom plate 55a, which becomes a bottom surface of the battery pack module 11 and is opposite the base plate 21 of the base 14, and an upper plate 55b, which becomes an upper surface of the battery pack module 11.

[0095] The five individual cells 41 are distributed or subdivided into a battery group G1 with three stacked cells and a battery group G2 with two stacked cells, and in the present embodiment a height difference or level difference, which is equivalent to a thickness of a single cell, is formed in the upper surface (upper plate 55b) of the perimeter plate 55.

[0096] Therefore, a level difference Z is formed in the upper surface of the battery pack module 11, and the control circuit board 12 is installed such that it corresponds to the position of the level difference Z (referring to Fig. 2).

[0097] Additionally, using a space formed by the level difference Z above the module, wiring of various connecting lines is carried out under the circuit board, or electrical components, such as a thermistor, are arranged there.

[0098] Each individual cell 41 has a few of maximum surface areas where the areas under the perimeter surfaces of the battery become the largest.

[0099] In addition, each individual cell 41 is included in the battery housing 42, so that they are stacked together in such a way that one of the maximum surfaces (the bottom side in the figure) is on the side of the base plate 21 and the other surface (top side in the figure) is on a side opposite the base plate 21.

[0100] A part of the individual cells 41 (an electrode side part) protrudes from the battery housing 42 in the state in which each individual cell 41 is received in the battery housing 42.

[0101] The insulation cover 43 is attached to the battery housing 42 in such a way that it covers a section where the individual cells 41 have protrusions.

[0102] Although cutouts (openings) which vertically penetrate the base plate 55a and the upper plate 55b are formed in the battery housing 42, the housing has a structure in which plates (parts of the upper plate 55b and the base plate 55a) abut each other in the vertical direction in at least certain areas, including central areas (J in Fig. 14) of the individual cells 41, opposite each other.

[0103] This means that it is assumed that the amount of swelling in the central region of the battery will be maximized when swelling occurs in each individual cell 41, and this has a structure in which plates opposite the casing, which are opposite the individual cells 41, exist in the central region of the battery.

[0104] A sensor mounting 59 for attaching a submersible sensor 122 (explained in more detail later) at a predetermined height relative to the upper surface of the base plate 21 of the base 14 is integrally formed on one side of the battery housing 42.

[0105] The sensor mounting 59 is arranged such that it protrudes laterally from the perimeter plate 55 of the battery housing 42, and the submersible sensor 122 should be installed at the same height as the base plate 55a of the battery housing 42 (referring to Fig. 2). Insulation cover 43

[0106] As in Fig. As shown in Figure 11, there are a plurality of (ten in this embodiment) openings 67 which are formed in the insulation cover 43 corresponding to the positions of the anode terminals 51 and the cathode terminals 52 of each individual cell 41.

[0107] The terminals 51 and 52 of each individual cell 41 are inserted into the majority of openings 67 by mounting the insulation cover 43 on the battery housing 42.

[0108] Then, in this state, a plurality of busbars 61 to 66 are attached to the insulation cover 43 in such a way that it closes each of the openings 67 ( Fig. 12).

[0109] The busbars 61 to 66 are electrode-connecting terminals which are connected to each electrode of the majority of the individual cells 41, which are aligned in vertical and horizontal directions, and connect each of these individual cells 41 in series.

[0110] A condition which is in Fig. Figure 12 shows the state in which the busbars 61 to 66 are attached to the insulation cover 43.

[0111] The four busbars 62 to 65 of all six busbars 61 to 66 are connecting terminals which electrically connect the individual cells 41 to each other.

[0112] The anode terminal 51 of the individual cell 41 and the cathode terminal 52 of the other cell 41 are electrically connected to these busbars 62 to 65 for each of the two individual cells 41 which are adjacent in the vertical or horizontal direction.

[0113] More precisely, the anode and cathode terminals 51 and 52 of two individual cells 41, which are adjacent in the vertical direction, are connected by the busbars 62 and 64, and the anode and cathode terminals 51 and 52 of two individual cells 41, which are adjacent in the horizontal direction, are connected by the busbars 63 and 65.

[0114] Furthermore, the busbar 61 is a connecting terminal for connecting the positive-side terminal of the battery pack, so that the five individual cells 41 are connected in series to the control circuit board 12.

[0115] Furthermore, busbar 66 is a connection point for connecting the negative terminal of the battery pack to ground.

[0116] The busbar 61 is connected to the anode terminal 51 of the individual cell 41, which is one end of a series battery circuit of the five individual cells 41.

[0117] Furthermore, connecting parts 61x, which are connected to the control circuit board 12, are formed on a projecting section which protrudes to a side opposite the battery, from the electrode connection parts which are connected to the anode connection 51 in the busbar 61.

[0118] More precisely, the connection parts 61x are arranged such that they extend in the direction of the area above the battery pack module 11.

[0119] Furthermore, the busbar 66 is connected to the cathode terminal 52 of the individual cell 41, which forms the other end of the series battery circuit.

[0120] Furthermore, a large connection part 66x, which is connected to the ground (for example, to the vehicle body), is formed on a protruding section, which extends to a side opposite the battery from the electrode connection parts which are connected to the cathode connection 52 in the busbar 66.

[0121] Voltage measuring terminals 61a to 66a, which protrude on a side opposite the battery, are uniformly arranged in each busbar 61 to 66.

[0122] Furthermore, as in Fig. As shown in Figure 12, a plurality of openings 68 (five openings in the present embodiment) are formed corresponding to the positions of the outlet valves 53 of each individual cell 41 in the insulation cover 43, these being different openings from the openings 67 mentioned above for the electrodes.

[0123] In the insulation cover 43, sections 69 are formed in the horizontal direction for each opening 68 of each battery group on one side opposite the battery, and seals 71 and 72 are attached to the respective recessed sections 69.

[0124] In this case, a total of five openings 73 are formed in the seals 71 and 72, and in a condition where the seals 71 and 72 are attached to the insulation cover 43, the openings 68 of the insulation cover 43 and the openings 73 of the seals 71 and 72 are connected to each other.

[0125] The insulation cover 43 is formed by a material which has electrical insulation properties, such as synthetic resins, such as polypropylene (PP resin) or PP resin which contains, for example, a filler or talc.

[0126] Additionally, it is preferable to form the insulation cover 43 with the synthetic resin, which has thermal resistance and thermal insulation properties.

[0127] The battery housing 42 and the insulation cover 43 are assembled using a plurality of metal fittings 75.

[0128] In particular, protruding sections are formed at the connection ends of both the battery housing 42 and the insulation cover 43, and the battery housing 42 and the insulation cover 43 are fastened by pressing together the protruding sections of both through the metal fittings 75. Outlet channel 44

[0129] Next, outlet channel 44 will be explained.

[0130] The outlet channel 44 has a collection chamber section which collects gas and electrolyte that flows out from the interior of the battery when the outlet valve 53 of each individual cell 41 is opened.

[0131] The outlet channel 44 has a first body 81 and a second body 82 to form the collection chamber section.

[0132] The first body 81 is arranged on the side of the battery, and the second body 82 is arranged on a side opposite the battery.

[0133] Each of the bodies 81 and 82 is formed with a material which has a thermal resistance, so that melting does not occur, even if the interior of the individual cell 41 assumes an unusual high-pressure state and hot gas and electrolyte, etc., flows out of the outlet valve 53, and thus these are formed, for example, by or with polyphenylene sulfide resin (PPS), polybutylene terephthalate (PBT) or various resins to which a flame retardant has been added, etc.

[0134] Furthermore, it is preferable to form the outlet channel 44 using the synthetic resin, which has thermal insulation properties.

[0135] A recessed section for forming a recovery space is formed in at least one of the bodies 81 and 82 (a recessed section 81b, which is arranged in a main body section 81a of the first body 81, is in Fig. 16 shown), and the collecting chamber section is formed in the interior of the channel where the two bodies 81 and 82 are joined.

[0136] The recessed section for forming recovery space can be formed in the second body 82, instead of adding it to the first body 81.

[0137] Additionally, a heat-resistant closure, which has a heat resistance, is arranged on a connecting part of both the body 81 and the body 82.

[0138] An outlet 83, which is connected to the collection chamber section within the channel, is uniformly formed with the first body 81.

[0139] The outlet 83 has the function of allowing the gas and electrolyte collected in the collection chamber section to escape to the exterior of the battery unit 10.

[0140] Furthermore, five openings 85 are formed at positions which correspond to each outlet valve 53 of the five individual cells 41 in the first body 81.

[0141] In the state where the outlet channel 44 is mounted on the insulation cover 43, the outlet valves 53 are connected to the openings 85 of the first body 81 by each opening 68 and 63 of the insulation cover 43 and the seals 71 and 72.

[0142] Additionally, seals 71 and 72 function as leak suppression devices, suppressing gas and liquid leaks.

[0143] In both bodies 81 and 82, the collection space section is large enough to cover all the outlet valves 53 of the insulation cover 43, and some busbars (busbars 63, 64 and 65) of busbars 61 to 66 are covered from the side opposite the battery by plate-like main body sections 81a and 82a to form a recovery space in addition to all the outlet valves 53.

[0144] On the other hand, the remaining busbars (busbars 61, 62 and 66) are not covered by the main body sections 81a and 82a.

[0145] In a number of locations, overhang plates 87 are arranged such that they project laterally from the main body section 81a in the first body 81, and the busbars 61, 62 and 66 are covered by the overhang plates 67 from the side opposite the battery.

[0146] Additionally, with reference to the busbars 61 and 66, not the entire parts of the busbars 61 and 66 are covered, but sections with the exception of the protruding parts (parts which form the circuit board-side connections and the ground-side connections) which protrude to a side opposite the battery are covered by the overhang plates 87.

[0147] The overhang plates 87 form a protective means to protect the busbars 61, 62 and 66, and the overhang plates 87 can suppress inconveniences where, for example, tools or other parts touch the busbars 61, 62 and 66 at the time of work on the group of battery pack module 11 during the assembly of the battery unit 10.

[0148] As in Fig. As shown in Figure 12, connecting rods 91, which extend to a side opposite the battery, are arranged at a plurality of locations (four locations in the present embodiment) in the insulation cover 43 as a structure for attaching the outlet channel 44 to the insulation cover 43.

[0149] Furthermore, a plurality of insertion parts 82, which have through holes for inserting the connecting rods 91, are formed in the outlet channel 44.

[0150] A male screw is formed at one end of each connecting rod 91, and when the connecting rods 91 are inserted into the through holes of the insert parts 92, the outlet channel 44 is attached to the insulation cover 43 by fastening nuts 93 to the male screws.

[0151] Furthermore, with reference to the battery pack in which five individual cells 41 are connected in series, the outlet channel 44 is provided with a voltage output conductor track or voltage output conductor path for outputting or supplying the connection voltage from each individual cell 41 to the control circuit board 12.

[0152] More precisely, as in Fig. As shown in Figure 17, the metal conductors 101 to 106 are formed into the second body 82 as a conductive element which outputs a detected voltage, which is detected by the voltage measuring terminals 61a to 66a from each busbar 61 to 66, to the control circuit board 12.

[0153] In addition, the voltage output conductor track for each busbar 61 to 66 is formed by the metal conductors 101 to 106.

[0154] All metal conductors 101 to 106 are rectangular flat conductors in their cross-sectional shape and are formed, for example, by punching a copper plate which has good electrical conductivity.

[0155] Electrode-side connection terminals 101a to 106a, which are connected to the measuring terminals 61a to 66a of the busbars 61 to 66, are provided at one end of each metal conductor 101 to 106.

[0156] The electrode-side connection terminals 101a to 106a are arranged in groups corresponding to the position of each measuring terminal 61a to 66a. Groups of matching positions, such as the electrode-side connection terminal 101a and the measuring terminal 61a, the electrode-side connection terminal 102a and the measuring terminal 62a, the electrode-side connection terminal 103a and the measuring terminal 63a, the electrode-side connection terminal 104a and the measuring terminal 64a, the electrode-side connection terminal 105a and the measuring terminal 65a, and the electrode-side connection terminal 106a and the measuring terminal 66a, are arranged in this manner.

[0157] The electrode-side connection terminals 101a to 106a are arranged such that they protrude outside the second body 82.

[0158] Furthermore, where not shown, penetration holes are formed in the electrode-side connection terminals 101a to 106a, and the measuring terminals 61a to 66a and the electrode-side connection terminals 101a to 106a are connected in the state in which the measuring terminals 61a to 66a are inserted into the penetration holes.

[0159] It is preferable that the connection be made by soldering, welding, adhesion, screw fastening, etc.

[0160] Furthermore, the control circuit-side connection terminals 107, which have the same number as the metal conductors 101 to 106, are connected to the other ends of the metal conductors 101 to 106.

[0161] Each of the control circuit-side connection terminals is made from a rod-like metal element with a square or round cross-sectional shape.

[0162] The control circuit-side connection terminals 107 are collectively arranged in a connection support part 88, which is formed in an upper part of the second body 82, and are arranged in the connection support part 88 in a predetermined arrangement (three in two rows, in the present embodiment).

[0163] Each of the control circuit-side connection terminals 107 extends upwards in the vertical direction, and the tips of these are connected to the control circuit board 12.

[0164] Each of the control circuit-side connection terminals 107 is formed by an elastically deformable elastic material, and a bending section 107a, acting as a displacement absorption element, is formed in one part in a longitudinal direction. However, the details of this will be mentioned later.

[0165] Additionally, it is preferred that the control circuit-side connection terminals 107 are connected to the metal conductors 107 to 106 by welding or fastening.

[0166] Furthermore, the control circuit-side connection terminals 107 can be integrally formed with the metal conductors 101 to 106. Control circuit board 12

[0167] Next, the control circuit board 12 will be explained.

[0168] The following are intended to ensure the secure state of the control circuit board 12 in the battery unit 10: Fig. 2, Fig. 3 and Fig. 6 will be mentioned.

[0169] As in Fig. As shown in Figure 18, the control circuit board 12 is made from a printed circuit board which has an L-shape (a re-entrant polygon), and various types of electronic components and the connector 18 are attached to the surface of the control circuit board.

[0170] A CPU (Central Processing Unit, control calculation element) as a control section, which performs a processing of a charging and discharging control of the battery pack module 11, etc., and the aforementioned power elements P are included in the electronic components.

[0171] The control circuit board 12 has an overlapping area which overlaps with the battery pack module 11 in the vertical direction (i.e., a section just above the battery pack module 11), and a non-overlapping area which does not overlap with the battery pack module 11 in the vertical direction, and the power elements P are arranged in the non-overlapping area.

[0172] Therefore, the element heat emitter 28 of the base 14 and the attached sections of the power elements P can be arranged opposite each other in the vertical direction, as mentioned above, and heat generated by the power elements P is emitted by the element heat emitter 28 (referring to Fig. 3).

[0173] Additionally, an insulating sheet 111 is arranged between the opposite plate part 29 of the element heat emitter 28 and the control circuit board 12, so that the element heat emitter 28 and the control circuit board 12 are electrically insulated (referring to Fig. 4 and Fig. 5).

[0174] The control circuit board 12 is located on one side of the battery pack module 11, which is opposite the base plate 21.

[0175] A plurality of through-holes 112, 113 and 114 are arranged on the control circuit board 12. The connecting parts 61x of the busbar 61 are inserted into the through-holes 112, the control circuit-side connection terminals 107 are inserted into the through-holes 113, and the busbar 17a (referring to Fig. 6) of the connecting block 17 is inserted into the through holes 114.

[0176] The connections etc. mentioned above are fixed in each of the through holes 112 to 114 by soldering.

[0177] Referring to the control circuit-side connection terminals 107, the connection terminals 107 are electrically connected to a voltage sensing circuit of the control circuit board 12 by fixing the control circuit-side connection terminals 107 to the through holes 113.

[0178] On the control circuit board 12, the through holes 113 are formed in the overlap area which overlaps with the battery pack module 11 in the vertical direction (i.e., the section which is located just above the battery pack module 11).

[0179] Furthermore, the battery pack module 11 has the battery group G1 with three stacked individual cells 41 and the battery group G2 with two stacked individual cells 41, and the through holes are formed just above a section which is located on the side of battery group G2 (lower step side).

[0180] This means that the control circuit-side connection terminals 107 are arranged using a space formed by a stepped part of an upper surface of the battery pack module 11 between the battery pack module 11 and the control circuit board 12.

[0181] Considering both the battery pack module 11 and the control circuit board 12, the relative position between these two can change due to vehicle vibration, changes in ambient air temperature, etc.

[0182] In particular, in the present embodiment, the battery pack module 11 and the control circuit board 12 are individually fixed to the base 14 of the storage housing 16 by means of fastening screws N.

[0183] Therefore, it is easy to create a relative displacement between these two, even though the battery pack module 11 and the control circuit board 12 can be firmly fixed to the base 14.

[0184] In this way, it is possible that a shutdown or a falling off, a break, etc., in the soldered section of the control circuit-side connection terminals 107 could occur due to such a relative displacement.

[0185] Consequently, in order to eliminate these inconveniences caused by the relative displacement between these two, the bending section 107a is designed as a displacement absorption part in each of the control circuit-side connection terminals 107, as shown in the Fig. 19A and Fig. 19B shown.

[0186] The bending section 107a is bent and formed in directions different from the longitudinal direction of the control circuit-side connection terminal 107 and is curved in a U-shape.

[0187] In this case, all of the majority of the control circuit-side connection terminals 107 are bent in the same direction to form the bending sections 107a.

[0188] In addition, a base-side straight section 107b extends below the bend section 107a and a tip-side straight section 107c extends above the bend section 107a of the control circuit-side connection terminal 107 in the vertical direction (in other words, these extend in a direction perpendicular to the circuit board surface), and these are formed aligned on the same straight line.

[0189] As in Fig. As shown in Figure 19B, the bending section 107a has three curved sections 108a, 108b and 108c, and the rising direction of the curved sections 108a and 108b of the upper and lower sides and the falling direction of the circular part 108c between these two are mutually reversed.

[0190] In this case, assuming that a load acts on the control circuit-side connection terminals 107 in a compressive direction or in a tensile direction, each curved section 108a to 108c is preferably designed with a radius of curvature which does not cause an unnecessary concentration of the load.

[0191] In this embodiment, the radius of curvature of each curved section 108a to 108c is set to a radius of curvature which is greater than the thickness (or diameter) of the control circuit-side connection terminals 107.

[0192] Furthermore, the three curved sections 108a to 108c are designed in such a way that elastic deformation does not concentrate on any one of them.

[0193] More precisely, the radii of curvature of the three curved sections 108a to 108c are essentially the same.

[0194] Therefore, if a load acts on the control circuit-side connection terminals 107 due to the generated vibration, etc., a concentration of a bending load on any of the curved sections 108a to 108c can be suppressed, and thereby the control circuit-side connection terminals can be protected.

[0195] Furthermore, there is an overhanging gap (L10 in) in the bending section 107a. Fig. 19B) in a direction which intersects perpendicularly with the longitudinal direction of the control circuit-side connection terminal 107, configured smaller than a distance between the control circuit-side connection terminal 107 in the control circuit board 12 and the connection support part 88.

[0196] Therefore, no interference occurs between the control circuit-side connection terminals 107.

[0197] Here, the stepped part, which differs in its height distance from the base plate 21, is arranged on the upper surface (the side opposite the base plate 21) of the battery pack module 11, as mentioned above, and a remote space is formed between a part which is lowered by the stepped part in the battery pack module 11 and the control circuit board 12 (referring to Fig. 2).

[0198] Then the control circuit-side connection terminals 107 are arranged in the remote room.

[0199] This means that the control circuit-side connection terminals 107 are located on the side of battery group G2, which is the lower group of the two battery groups G1 and G2 of the battery pack module 11.

[0200] In this case, although the battery pack module 11 and the control circuit board 12 are arranged opposite each other in the position where they overlap, a space for arranging the bending section 107a can be ensured by using the space formed by the stepped part in the upper surface of the battery pack module 11, thereby creating a desired function of absorbing a displacement.

[0201] This means that if the battery pack module 11 and the control circuit board 12 are too close to each other, it will be difficult to form the bending sections 107a in the control circuit-side connection terminals 107 which connect these two.

[0202] However, by providing a moderate or adequate space, as explained above, the bending sections 107a in the control circuit-side connection terminals 107 can be appropriately formed.

[0203] By forming the bending sections 107a in the control circuit-side connection terminals 107, as mentioned above, the positional displacement mentioned above can be absorbed by a deformation of the bending section 107a in the control circuit-side connection terminal 107, even if any displacement occurs when the battery pack module 11 and the control circuit board 12 move closer together or further away from each other.

[0204] Furthermore, it is also possible to cope even if the positional shift occurs in one direction along the surface of the control circuit board (the horizontal direction in the figure).

[0205] Therefore, circumstances due to mechanical overload acting on any of the battery pack module 11, the control circuit board 12 and the control circuit-side connection terminals 107 due to the relative displacement mentioned above can be suppressed.

[0206] When the control circuit board 12 is mounted to the battery unit 10, the control circuit-side connection terminals 107 are inserted into the through holes 113 of the control circuit board 12, and in this state the control circuit board 12 is fixed to the base 14 with fastening screws.

[0207] In this case, if spacing errors occur in each part, there are concerns that the control circuit-side connection terminals 107 may be unable to be inserted into the through holes 113, or that an unnecessary load may be applied to the control circuit-side connection terminals 107 when the control circuit board 12 is fixed to the base 14.

[0208] However, these problems regarding the assembly of the control circuit board 12 can be suppressed by forming the bending section 107a in the control circuit-side connection terminal 107.

[0209] The submersible sensor 122, as a submersible sensor, is connected by an electrical wiring 121, as shown in Fig. 18 shown, connected to the control circuit board 12.

[0210] The immersion sensor 122 detects immersion of the battery unit 10 when water is detected that has entered the battery unit 10.

[0211] The submersible sensor 122 has a circuit board 122a and a water detector 122b, which are mounted as a single assembly on an upper surface of the circuit board 122a.

[0212] Additionally, as in Fig. As shown in Figure 2, the submersion sensor 122 is attached to the sensor mounting 59 by fixing the circuit board 122a to the sensor mounting 59 of the battery housing 42.

[0213] An explanation regarding the mounting position of the control circuit board 12 and the submersion sensor 122 in the battery unit 10 has been added here.

[0214] The submersible sensor 122 is arranged in a position which is lower than the upper end part of the collar section 23 of the wall section 22 (a position which is closer to the base plate 21 than the upper end part of the wall section 22) in a space inside the housing 16 which is surrounded by the wall section 22, by attaching the sensor 122 to the sensor mounting 59 which is formed uniformly with the battery housing 42.

[0215] Furthermore, the control circuit board 12 is arranged in a position which is higher than the upper end part of the collar section 23 (a position which is further away from the base plate 21 than the upper wall end part of the wall section 22) by fixing the control circuit board 12 to the upper end parts of the support columns 24 of the wall section 22.

[0216] This means that the submersion sensor 122 is positioned lower than the water ingress height, which is the height of the water penetrating the interior of a housing, and the control circuit board 12 is positioned higher than the water ingress height in the battery housing 42.

[0217] To do this with Fig. To explain point 2, the height of the collar section 23 of the wall section 22 (the height from the bottom of the battery unit 10) is H1.

[0218] On the other side, the height of the submersion sensor is 122 H2 and the height of the control circuit board is 12 H3.

[0219] The relationship between these heights will be H2 H1.<h1>

[0220] In this case, flooding of the space inside the housing 16 does not occur until the water level exceeds the wall height H1 of the wall section 22 in the situation where the vehicle is flooded with water and the battery unit 10 has submerged.

[0221] Then, when the water level exceeds the wall height H1 of the wall section 22, the flooding (i.e., the submersion) is detected by the submersion sensor 122 with a start of flooding in the space inside the housing 16.

[0222] Since the control circuit board 12 is not yet flooded when the flooding starts, the CPU (control section) of the control circuit board 12 can execute arrangements such as suspending the charging and discharging of the battery pack module 11 by itself based on a detected signal from the submersion sensor 122 before a functional stop, etc., of the battery unit 10 occurs, which is caused by the flooding.

[0223] Since the positions in the vertical direction of the upper end part (the upper wall end part) of the collar section 23 and the control circuit board 12 are different, a gap with a size of H3-H1 is formed in the vertical direction between these two (referring to Fig. 2).

[0224] Therefore, if water penetrates, it will flow through the aforementioned gap and enter the space inside the housing 16.

[0225] Therefore, the ingress of water can be detected by the submersion sensor 122 before the water level reaches the height position of the control circuit board 12.

[0226] Furthermore, as mentioned above, the base 14 and the cover 15 of the storage housing 16 are assembled in such a way that the wall section 22 of the base 14 is arranged inside the housing 16, and the hanging walls 36 of the cover 15 are arranged outside the housing 16, so that they overlap inside and outside in the horizontal direction (referring to Fig. 2 and Fig. 3).

[0227] Therefore, if the battery unit 10 is only slightly submerged in water or water is splashed onto the battery unit 10, the submersion sensor 122 will not detect the submersion, thus suppressing an incorrect detection of the submersion.

[0228] This prevents unnecessary termination of the charging and discharging of the battery pack module 11, etc. Retaining plate 13

[0229] Next, the retaining plate 13 is explained.

[0230] For the installed state of the retaining plate 13 in the battery unit 10, the following shall apply: Fig. 2, Fig. 5 and Fig. 6 will be mentioned.

[0231] As in Fig. 20A and Fig. As shown in Figure 20B, the retaining plate 13 is made of a tubular, highly stable metal plate which has a predetermined thickness (for example, a few millimeters).

[0232] The retaining plate 13 has a stepped plate 131 extending in one direction towards the stepped part of the upper surface of the battery pack module 11 (of the battery housing 42), and a plurality of arm plates 132 to 135 extending laterally from the stepped plate 131.

[0233] That is, the retaining plate 13 has a curved shape corresponding to the shape of the stepped part of the upper surface of the battery pack module 11.

[0234] An end part of an upper level of the stepped plate 131 and tips of each arm plate 132 to 135 are used as fixing sections for fixing the retaining plate 13 to the base 14, and each of these sections is provided with penetration holes for inserting fastening screws.

[0235] That is, the retaining plate 13 is attached to the base 14 by fastening the end part of the upper level of the stepped plate 131 and the tips of each arm plate 132 to 136 with screws to the upper end parts of the support columns 24 of the base 14.

[0236] This means that the retaining plate is arranged such that it touches each ascending section (the wall section 22 and the mounting columns 25) formed in the base 14 and surrounding the battery pack module 11 in every direction.

[0237] The retaining plate 13 has a swelling suppression function which suppresses deformation of the individual cell 41 of the battery pack module 11 when excessive swelling of the cell occurs, and it has a heat dissipation function which radiates the heat which has occurred in the battery pack module 11 or the control circuit board 12 to the outside of the housing 16.

[0238] Each of these functions is explained below.

[0239] First, the swelling suppression function is explained.

[0240] In addition, the swelling suppression function is not only realized by the retaining plate 13, but also by the base 14 and the battery housing 42 in the battery unit 10, which is why the base 14 and the battery housing 42 are also mentioned here.

[0241] Protruding sections 136, which extend from the two plate surface sides towards one side of a plate surface, are arranged at two locations in the stepped plate 131 such that they correspond to both battery group G1 with three stacked cells and battery group G2 with two stacked cells.

[0242] That is, the protruding sections 136 are each formed in a side section of the upper level 131a and a side section of the lower level 131b of the stepped plate 131.

[0243] The protruding sections 136 extend towards one side of the battery pack module 11 in a state in which the stepped plate 131 is installed in the base 14.

[0244] The protruding sections 136 have contact surfaces 137 which touch the battery pack module 11 (swollen sections on sides opposite the side of the base plate 21) when the swelling of the individual cell 41 occurs.

[0245] Furthermore, as mentioned above, the projecting sections 32 are formed projecting upwards into the base plate 21 of the base 14 (referring to Fig. 8A).

[0246] The protruding sections 32 have the contact surfaces 33 which touch the battery pack module 11 (swollen sections in the side of the base plate 21) when swelling of the individual cell 41 occurs.

[0247] It should be estimated that the protruding section 32 of the base 14 is equivalent to a first protruding section, and that the protruding section 136 of the retaining plate 13 is equivalent to a second protruding section.

[0248] For the sake of simplicity, the protruding section 32, which is equivalent to a first protruding section, is hereby also referred to as the protruding section of the lower side 32, and the protruding sections 136, which are equivalent to the second protruding section, are likewise referred to as the protruding section of the upper side 136.

[0249] As in Fig. As shown in Figure 2, the protruding sections of the upper side 136 and the protruding sections of the lower side 32 are arranged in the vertical positions with the battery pack module 11 in between when the battery pack module 11 and the retaining plate 13 are mounted to the base 14.

[0250] In this case, the protruding sections of the lower side 32 are designed such that these areas touch which become central areas of the bottom surface sides of the individual cells 41 under the base plates 55a of the battery housing 42.

[0251] In addition, the protruding sections of the upper side 136 are designed such that these areas touch which become central areas of the upper surface sides of the individual cells 41 under the upper plates 55b of the battery housing 42.

[0252] In particular, in the assembled state, which is in Fig. As shown in Figure 2, in the present embodiment the upper plate 55b of the battery housing 42 and the protruding sections of the upper side 136 of the retaining plate 13 do not come into contact with each other if the swelling of the individual cell 41 has not occurred, and a predetermined gap is formed between the upper plate 55b of the battery housing 42 and the protruding sections of the upper side 136 of the retaining plate 13.

[0253] This gap (separating distance) is, for example, 0.3–1.0 mm. Additionally, the base plate 55a of the battery housing 42 and the protruding section of the lower side 32 of the base 14 below the battery pack module 11 are in contact with each other.

[0254] Each individual cell is stacked in the thickness direction of the battery in the battery pack module 11, and when swelling occurs in each individual cell 41, the amount of swelling in the central regions of both the upper surface and the lower surface of the individual cell 41 will be a maximum.

[0255] At this point, the condition in which the base plate 55a of the battery housing 42 touches the protruding section of the lower side 32 is maintained below the battery pack module 11.

[0256] Furthermore, the swelling of the individual cell 41 is enabled according to the amount of the gap above the battery pack module 11, and when the individual cell 41 swells to the amount of the gap, the upper plate 55b of the battery housing 42 touches the protruding sections of the upper side 136 of the retaining plate 13.

[0257] Since the retaining plate 13 is made of a plate with high stability and does not deform elastically, even if the retaining plate 13 absorbs the load caused by the swelling of the individual cell 41, the swelling of the individual cell 41 is suppressed in the state in which the upper plate 55b of the battery housing 42 touches the protruding sections of the upper side 136.

[0258] Therefore, the deformation of the individual cell 41 due to swelling can be suppressed.

[0259] Here, the separating distance between the battery housing 42 and the retaining plate 13 in a position of maximum swelling, which includes a section where the amount of swelling becomes the maximum when the individual cell swells, differs from the other positions, and the separating distance is smaller in the position of maximum swelling.

[0260] This means that the separating distance between the battery housing 42 and the retaining plate 13 is different in an area which corresponds to the central area of ​​the upper surface of the individual cell 41 and other areas.

[0261] The protruding sections of the upper side 136 are formed on the retaining plate 13 by the protrusion of parts of it as a specific structure.

[0262] Therefore, when swelling occurs in each individual cell 41, the contact surfaces 137 of the protruding sections of the upper side 136 preferably touch the battery housing 42 (swollen sections on sides opposite the side of the base plate 21) more than other sections of the retaining plate 13.

[0263] Furthermore, when swelling occurs in each individual cell 41, the contact surfaces 33 of the protruding sections of the lower side 32 touch the battery housing 42 (swollen sections on the side of the base plate 21) in a similar manner in the base 14, preferably more than other sections.

[0264] In the case of the battery pack module 11, such a design is suitable to suppress swelling in the areas where the amount of swelling of the individual cell 41 is maximized.

[0265] Furthermore, the separating plates 56 are placed between each individual cell 41, which are stacked vertically in the battery housing 42, and if swelling occurs in each individual cell 41, the swelling is also suppressed by the contact of the separating plates 56 by each individual cell 41.

[0266] In this case, contact between the individual cell 41 can be suppressed by the separating plates 56 when swelling occurs.

[0267] Next, the heat emission function of the retaining plate 13 will be explained.

[0268] As in Fig. As shown in Figure 2, the retaining plate 13 is arranged along the upper surface of the battery pack module 11.

[0269] A section in an upper part of the battery group G2 with two stacked cells is arranged and temporarily stored between the battery pack module 11 and the control circuit board 12.

[0270] A section in an upper part of the battery group G1 with three stacked cells is arranged near the control circuit board 12 in the horizontal direction with the same height position as the control circuit board 12.

[0271] The end part of the upper level of the stepped plate 131 and the tips of each arm plate 132 and 135 are attached to the upper end parts of the support columns 24 of the base 14 in the retaining plate 13 with screws.

[0272] Therefore, this design features a structure in which the heat generated in the battery pack module 11 or the control circuit board 12 escapes to the wall section 22 of the base 14 through the retaining plate 13.

[0273] In this case, the retaining plate 13 functions as a heat radiating element and a radiation path is formed through the retaining plate 13 and the wall section 22.

[0274] The heat, which is conducted to the wall section 22 of the base 14 through the retaining plate 13, is further conducted to the base plate 21 and radiated to the atmosphere through the ribs 27, which are formed in the bottom surface of the base plate 21, and the heat is also radiated outwards by being conducted from the base plate 21 to the vehicle body.

[0275] In particular, the aforementioned design allows for the suppression of problems caused by heat acting on both the battery pack module 11 and the control circuit board 12 by interposing the retaining plate 13 as a heat dissipation element between the battery pack module 11 and the control circuit board 12. The heat suppression structure inside the storage case 16

[0276] The majority of the individual cells 41 and the power elements P are understood as a heat source with a large caloric value or heat value of each component in the battery unit 10.

[0277] In the present embodiment, a structure is provided which makes it difficult for the influence of heat to reach the individual cells 41 and the power elements P, and the structure of this structure is explained below.

[0278] As in Fig. As shown in Figure 3, the control circuit board 12 has a first circuit section X1, which is arranged such that it overlaps with the battery pack module 11 in the vertical direction, and a second circuit section X2, which is arranged such that it does not overlap with the battery pack module 11 in the vertical direction, and the power elements P are attached in the second circuit section X1 of the control circuit board 12.

[0279] In this case, when referring to an arrangement of the individual cells 41 and the power elements P, the individual cells 41 and the power elements P are not arranged in positions in the vertical direction, but are arranged in positions that are separated in the horizontal direction.

[0280] Furthermore, the element heat emitter 28 is arranged in a position opposite the surface of the circuit board of the second circuit section X1 (a surface opposite the surface where the elements are mounted), and the element heat emitter 28 is arranged side by side relative to the battery pack module 11 in the direction in which the surface of the circuit board of the control circuit board 12 extends (the left-to-right direction in Fig. 3).

[0281] Furthermore, the battery pack module 11 is arranged in the storage housing 16 in a position in which the insulation cover 43 and the outlet channel 44 of the heat radiating section 28 are opposite each other.

[0282] In the aforementioned setup, the heat generated in each individual cell 41 is directed directly to the base plate 21 of the base 14, and is also directed to the base plate 21 through the retaining plate 13 and the wall section 22, and then the heat is radiated from the base plate 21 to the outside of the unit.

[0283] On the other hand, the heat generated in the power elements P is radiated to the outside of the unit by the element heat emitter 28.

[0284] At this point, since different radiation routes or paths are provided for the individual cells 41 and the power elements P, and the power elements P are arranged in such a way that they do not overlap with the battery pack module 11 in the control circuit board 12, heat influences between the individual cells 41 and the power elements P are suppressed.

[0285] Furthermore, the insulation cover 43 and the outlet channel 44 exist on the side of the power elements P in the battery pack module 11.

[0286] In other words, the insulation cover 44 and the outlet channel 44, which is made of a synthetic resin, are arranged between the majority of the individual cells 41 and the element heat emitter 28.

[0287] Mutual heat exchange between the individual cells 41 and the power elements P is suppressed by the existence of the insulation cover 43 and the outlet channel 44.

[0288] This means that the heat generated in the individual cell 41 is not easily conducted to the power elements P, and conversely, the heat generated in the power elements P is not easily conducted to the individual cell 41.

[0289] This allows the heat influence between the individual cells 41 in the power elements P to be further suppressed.

[0290] Additionally, it is also assumed that the heat from the battery pack module 11 can be directed to the element heat emitter 28.

[0291] At this point, the majority of the ribs 30 are formed in the element heat emitter 28, extending from the side of the battery pack module 11 to an opposite side thereof, and the ribs 30 are arranged separately on one side opposite the battery pack module 11 and on one side of a bottom surface of the housing (referring to Fig. 5 and Fig. 8B).

[0292] Therefore, when the heat from the battery pack module 11 is directed to the element heat emitter 28, the heat is directed from the side of the battery pack module 11 to the opposite side of it and radiated through each fin 30, resulting in a high heat radiation effect.

[0293] For example, the heat radiation effect can be increased compared to the design which only has the majority of ribs 30 arranged on the side opposite the battery pack module 11. An electrical design of a vehicle's electrical power system

[0294] Next, an overview of the electrical setup of the present electrical power system will be given using the Fig. 21 explained.

[0295] In the battery unit 10, the battery pack module 11 has the five individual cells 41 which are connected in series, so that the anode and the cathode of each individual cell is connected to a controller 152 via wiring 151.

[0296] The controller 152 is formed by the CPU (Central Processing Unit, controlling calculation element), which performs the processing of the charging and discharging control of the battery pack module 11, and which is mounted on the control circuit board 12.

[0297] Busbars 61 to 66, which are in Fig. As shown in Figure 12, 41 are arranged on the anode side and the cathode side of each individual side, and the wiring 151 is formed by the metal conductors 101 to 106, which are in Fig. 17 are explained.

[0298] Furthermore, while the battery unit has 10 connection terminals 153, 154 arranged and the connection terminals 153, 154 are mutually connected by a wiring 155, the battery pack module 11 is connected by a wiring 156 which branches off from the wiring 155.

[0299] Furthermore, a switch 157 is arranged in the wiring 155, and another switch 158 is arranged in the wiring 156.

[0300] The switching elements 157, 158 are switching elements for electrical power control, which consist, for example, of a power MOSFET, and which are equivalent to the power elements P, which are, for example, in Fig. 6 are shown.

[0301] Furthermore, the submersible sensor 122 is connected to the controller 152.

[0302] In the present in-vehicle electrical power system, a lead-acid battery 161 is provided next to the battery unit 10 as a power supply, and the lead-acid battery 161 is connected to the connection terminal 153 of the battery unit 10.

[0303] The charging of the battery unit 10 and the lead-acid battery 161 by the power generator 162 (alternator) is carried out in a suitable manner.

[0304] Furthermore, a starter 163 is arranged as an electrical load for starting a machine, and when the machine is started by using the starter 163, the electrical power to the starter 163 is supplied essentially by the lead-acid battery 161.

[0305] On the other hand, in the battery unit 10, although this is not shown, there are electrical loads 164, which are not the starter, such as audio equipment or navigation equipment, connected to the connection terminal 164, and the electrical power is supplied from the battery pack module 11 to the current consumers 164.

[0306] To briefly explain how the controller 152 controls the switch 157: the ON (closed) and OFF (open) positions of the switch 157 are controlled based on power stored in the battery pack module 11 and power stored in the lead-acid battery 161.

[0307] More precisely, if the power stored in the battery pack module 11 is greater than a predetermined value K1, the switch 157 is turned off.

[0308] On the other hand, if the power stored in the battery pack module 11 is lower than the predetermined value K1, the switch 157 is turned on, and the charging of the battery pack module 11 with the power generator 162 is carried out.

[0309] Furthermore, if the power stored in the lead-acid battery 161 is greater than a predetermined value K2 when the machine is started by the starter 163, the switch 157 is switched off and the electrical power is supplied from the lead-acid battery 161 to the starter 163.

[0310] On the other hand, if the power stored in the lead-acid battery is lower than the predetermined value K2, the switch 157 is turned on and the electrical power is supplied from the battery unit 10 to the starter 163.

[0311] The vehicles in which the present electrical power system is installed have an idle-stop function which automatically stops the machine according to a driving condition of the vehicle when an ignition switch is ON, and when predetermined automatic stop conditions are met, the machine is automatically stopped by an in-vehicle ECU (idle-stop ECU).

[0312] Furthermore, if predetermined restart conditions are met after the automatic machine stop, the starter 163 is driven by the in-vehicle ECU, and the machine restarts.

[0313] The automatic stop conditions include, for example, that an accelerator is OFF, that a brake is ON, or that a vehicle speed is below a predetermined speed, etc.

[0314] Furthermore, the restart condition includes, for example, that the accelerator is ON, or the brake is OFF, etc. Installation of battery unit 10

[0315] Although not shown in detail in the figures, the battery unit 10 is arranged on a floor of the vehicle which forms a passenger compartment of the vehicle, and more precisely, the battery unit is arranged below a front seat of the vehicle such that the base plate 21 of the base 14 is flat.

[0316] Since the battery unit 10 is located in the passenger compartment of the vehicle, water or mud, etc., will be unlikely to reach the battery unit 10 during vehicle operation, compared to a case where the battery 10 is located, for example, in an engine compartment.

[0317] The battery unit 10 can be located in a location other than under the front seat.

[0318] For example, the battery unit 10 can be located in a space between a rear seat and a trunk, a space between a driver's seat and a passenger seat, etc.

[0319] According to the present embodiment, which is explained in full detail above, the following remarkable effects are achieved.

[0320] The control circuit board 12 is arranged in the position which is higher than the upper wall end part (the upper end part of the collar section 23) of the wall section 22, while the submersion sensor 122 is arranged in the space inside the housing 16 which is surrounded by the wall section 22, and in the position which is lower than the upper wall end part (the upper end part of the collar section 23) of the wall section 22.

[0321] Therefore, flooding of the space inside the housing 16 does not occur until the water level exceeds the wall height of wall section 22 in the situation where the vehicle is flooded with water and the battery 10 is submerged.

[0322] Then, when the water level exceeds the wall height of wall section 22, the flooding (i.e., the submersion) is detected by the submersion sensor 122 with the start of flooding of the space inside the housing 16.

[0323] Since the control circuit board 12 is not yet flooded when the flooding begins, the control section of the control circuit board 12 can make arrangements such as suspending the charging and discharging of the battery pack module 11 by itself based on a detected signal from the submersion sensor 122, before a functional stop, etc., of the battery unit 10 caused by the flooding occurs.

[0324] Furthermore, since the wall section is designed in such a way that it surrounds the battery pack module 11 in the base 14, if, for example, the battery unit 10 is only slightly flooded with water or water is splashed onto the battery unit 10, the submersion sensor 122 does not detect the submersion, thus suppressing incorrect detection of submersion.

[0325] Therefore, unnecessary termination of the charging and discharging of the battery pack module 11, etc., is suppressed.

[0326] The base 14 and the cover 15 of the storage housing 16 are assembled in such a way that one of the wall sections 22 of the base 14 and the hanging walls 36 of the cover 14 is arranged inside the housing 16, and the other is arranged outside the housing 16 such that they overlap inside and outside in the horizontal direction.

[0327] Therefore, in the condition where the battery unit 10 is flooded with water, the water outside the unit enters the space inside the housing 16 after passing through the gap between the wall section 22 and the hanging walls 36, and in this way it can be avoided that the water immediately flows into the space inside the housing 16.

[0328] Therefore, if the battery unit 10 is flooded with water, it is possible to take the time from the water detection of the submersion sensor 122 until the submersion of the control section, and to reliably complete the charging and discharging of the battery pack module 11 by the control section.

[0329] The base 14 and the cover 15 are mounted in the state in which the wall section 22 of the base 14 is arranged inside the housing 16, and the hanging walls 36 of the cover 15 are arranged outside the housing 16.

[0330] This widens the gap between the wall section 22 of the base 14 and the hanging walls 36 of the cover 15 in the floor (the side of the base plate 21 of the base 14).

[0331] Therefore, if the water is lightly splashed onto the outside of the housing 16, the water does not enter the interior of the housing 16, and a false detection of submersion can be suppressed.

[0332] The control circuit board 12 is fixed on the upper end part of the support columns 24, which extend higher than the upper end part of the collar section 23 (i.e., to a side opposite the side of the base plate) in the wall section 22 of the base 14.

[0333] In this way, a gap is formed between the upper end part of the collar section 23 and the control circuit board 12.

[0334] In this case, during the process of the water level rising, flooding of the control circuit board 12 can be suppressed if water enters, since the water enters the space inside the housing 16 through the aforementioned gap.

[0335] Since the gap is formed between the upper end part of the collar section 23 and the control circuit board 12, the connection status of the control circuit board 12 and the battery pack module 11, etc., can be visually checked through the gap in the state where the cover 15 is removed.

[0336] The sensor mounting 59 for attaching the submersible sensor 122 is integrally formed on the outer side of the battery housing 42.

[0337] Therefore, the 122 submersible sensor can be easily installed.

[0338] This means that the submersible sensor 122 can be installed at a desired height position simultaneously with the installation and fixing of the battery pack module 11, when the battery pack module 11 is installed and fixed to the base 14. Other embodiments

[0339] The embodiment mentioned above can be modified, for example, as shown below.

[0340] The assembly of the battery housing 42 in the battery pack module 11 can be carried out as in Fig. 22 shown, will be changed.

[0341] Fig. Figure 22 is a sectional view showing part of the structure of Fig. 14 has been changed.

[0342] It should be noted that in the embodiments below, components which are identical or similar to those of the embodiment mentioned above are designated with the same reference numerals, and their structures and features are not described in order to avoid redundant explanation.

[0343] A in Fig. 22 Battery housing 171 shown has a perimeter plate 172, which is a perimeter part, and separating plates 173, which are arranged between the individual cells 41, which are stacked vertically, and the battery housing 171 has a structure such that it supports the individual cells 41 by contacting at least a part of the perimeter surface of the individual cell 41.

[0344] This means that each of the five battery storage sections (the storage space) in the battery housing 171 is designed as a space in which a distance in a vertical direction (a distance in a thickness direction of the battery) is small in a rear part of the housing and a distance in a vertical direction (distance in a thickness direction of the battery) is large in an entrance of the housing, and the individual cell 41 is stored in a section in a rear part of the housing in which the space becomes narrow.

[0345] More precisely, if the distance in the vertical direction of the rear of the housing is defined as L1, and the distance in the vertical direction of the entrance of the housing is defined as L2, then there is a relationship between the distances L1 <L2.

[0346] Furthermore, the battery housing 171 is suitable to undergo elastic deformation by pressing the individual cell 41, and the distance in the vertical direction of the rear part of the housing L1 (here, a distance before the individual cell is received) is slightly smaller than the distance L3 in the thickness direction of the individual cell 41.

[0347] Therefore, a part of the individual cell 41, which is positioned in the rear of the housing, is fixed firmly in the vertical direction by pressing the individual cell 41 into the rear of the housing on the battery housing 171.

[0348] On the other hand, gaps are formed between the battery housing 171 and a perimeter surface of the individual cell 41 in the vertical direction at the entry of the housing.

[0349] In this case, a section of the individual cell 41, which protrudes from the battery housing 171, is supported by the insulation cover 43, thereby preventing the individual cell 41 from wobbling, even if gaps are formed between the battery housing 171 and the perimeter surface of the individual cell 41 at the point where the housing enters.

[0350] The gap between the individual cell 41 and the battery housing 171 in the vertical directions is formed in the central regions of the individual cell 41, i.e., the parts where the amount of swelling becomes maximum when swelling occurs in the individual cell 41, and the upper surface and the bottom surface of the battery in the battery central region are opposite the battery housing 171 with a predetermined gap between them.

[0351] Although the gap spacing in the present embodiment is approximately 1 mm, it can be arranged within the limits of 0.5 to 2 mm.

[0352] In the battery housing 171, the difference in the distance between L1 and L2 can be achieved by arranging flanks or inclinations which are inclined relative to a horizontal direction of the base plate 172a of the battery housing 171 and an upper plate 172b of the separating plates 173.

[0353] Furthermore, the difference can be achieved by arranging surfaces with varying heights in each plate.

[0354] In the aforementioned structure of the Fig. 22 in the battery housing 171 each stacked individual cell 41 is arranged with a predetermined separation distance relative to the separating plates 173 in the state in which swelling in one stacking direction has not occurred.

[0355] This means that the central areas of the upper and bottom surfaces of each individual cell 41 are separated from the battery housing 171, and it has a structure in which the swelling of each individual cell 41 in the battery housing 171 is enabled by the gap between the separated sections.

[0356] In this case, if the swelling of the individual cell 41 is normally suppressed by contact between the perimeter side of the individual cell 41 and the battery housing 171, it must be taken into account that an unnecessary load is applied to each individual cell 41 accordingly; however, such an inconvenience can be suppressed.

[0357] In the embodiment mentioned above, the majority of the support columns 24 extend upwards from the collar section 23 into the wall section 22 of the base 14, and the battery pack module 11, the control circuit board 12 and the retaining plate 13 are fixed to the support columns 24.

[0358] However, the above structure can be modified to include flat or pillar-shaped rising sections which are designed to extend upwards independently of the wall section 22 on the base 21, and in which the battery pack module 11, the control circuit board 12 and the retaining plate 13 are fixed to the rising sections.

[0359] In the embodiment mentioned above, the base 14 and the cover 15 are mounted in the state in which the wall section 22 of the base 14 is arranged inside the housing 16, and the hanging walls 36 of the cover 15 are arranged outside the housing 16 such that they overlap inside and outside in the horizontal direction.

[0360] However, the above structure can be modified such that the base 14 and the cover 15 can be mounted in the state in which the wall section 22 of the base 14 is arranged outside the housing 16, and the hanging walls 36 of the cover 15 are arranged inside the housing 16 such that they overlap inside and outside in the horizontal direction.

[0361] With this setup, when the battery unit 10 is flooded with water, the water flows downwards from the upper section between the wall section 22 and the hanging walls 36, and the water enters the storage housing 16 from the lower end of the hanging walls 36.

[0362] This means that the water penetrates in a position which is lower than the wall section 22 (collar section 23) of the base 14.

[0363] Therefore, it can be made difficult for the control circuit board 12 to be flooded with water at the beginning of the water ingress.

[0364] In the embodiment mentioned above, the control circuit board 12 is arranged such that part of it overlaps with the battery pack module 11 (so that they are opposite each other).

[0365] However, the above structure can be modified so that the control circuit board 12 can be arranged in such a way that a whole part of it overlaps with the battery pack module 11 (so that they are opposite each other).

[0366] In the embodiment described above, the sensor mounting 59 is integrally formed with the battery housing 42, and the submersion sensor 122 is attached to the sensor mounting 59. However, this configuration can be modified, and a sensor mounting can be integrally formed with the base 14.

[0367] The sensor mounting can be arranged, for example, in or on the base plate 21 of the base 14 or in the wall sections 22.

[0368] In the above embodiment, the battery unit 10 is arranged below the seat in the vehicle.

[0369] However, the above structure can be modified so that it is possible to arrange the battery unit 10 in a dashboard of the vehicle or in a machine compartment.

[0370] In the above embodiment, the lithium-ion battery is used as a single cell.

[0371] However, the above structure can be modified so that other rechargeable batteries, such as a NiCad (nickel-cadmium) battery or a plurality of nickel-metal hydride batteries, can be used as a single cell.

[0372] The battery unit of the aforementioned embodiment can be used for a hybrid vehicle which uses both an internal combustion engine and a motor as a power source for driving the vehicle, or it can be used for an electric vehicle which does not have an internal combustion engine, but only a motor as a power source for driving the vehicle.

Claims

[1] Battery unit (10) comprising: a battery pack module (11) comprising a plurality of individual cells (41); a control circuit board (12) which has a control section which controls charging and discharging in the battery pack module (11); a storage housing (16) in which the battery pack module (11) and the control circuit board (12) are accommodated; a base (14) of the storage housing (16), wherein the base (14) has a base plate (21) where the battery pack module (11) is installed, and where a wall section (22) rises from the base plate (21) such that it surrounds the battery pack module (11); and a submersion sensor (122) which is electrically connected to the control section and which detects the submersion of the battery unit (10); wherein the control circuit board (12) is arranged in a position which is located on a side of the battery pack module (11) opposite the base plate (21), and which is separated from the base plate (21) by a distance which is greater than a distance from the base plate (21) to an upper wall end part of the wall section (22); and wherein the submersion sensor (122) is arranged in a position which is closer to the base plate (21) than to the upper wall end part of the wall section (22), which is located in a space within the housing which is surrounded by the wall section (22), where: the wall section (22) has a collar section (23) which is designed to be continuous in such a way that it surrounds the battery pack module (11), and which has an upper end part as the upper wall end part, and which has a plurality of support columns (24) which are higher than the upper wall end part, and the control circuit board (12) is fixed to the upper end part of the support columns (24). [2] Battery unit (10) according to claim 1, wherein: the storage housing (16) has a cover (15) which is attached to the base (14), the cover (15) has an upper plate (35) which covers the control circuit board (12) and hanging walls (36) which extend from the upper plate (35), the base (14) and the cover (15) are mounted in a state in which one of the wall sections (22) of the base (14) and the hanging walls (36) of the cover (15) is located inside the housing and another is located outside the housing, so that they overlap in a horizontal direction inside and outside. [3] Battery unit (10) according to claim 2, wherein the base (14) and the cover (15) are mounted in the state in which the wall section (22) of the base (14) is arranged inside the housing and the hanging walls (36) of the cover (15) are arranged outside the housing. [4] Battery unit (10) according to any one of claims 1 to 3, wherein the battery pack module (11) has a battery housing (42) where the majority of the individual cells (41) are accommodated, the battery housing is installed on the base plate (21) such that the battery housing is arranged in a space within the housing, and a sensor mounting (59) for attaching the submersion sensor (122) is integrally formed on an outer surface of one side of the battery housing (42).

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