Battery module and method for inspecting the battery module

Abstract

To provide: a battery module that can be efficiently inspected without applying an electrical load to the battery module; and a method for inspecting the battery module.SOLUTION: A battery module includes: unit cells 13 each having a battery container 13a that houses battery elements; thermistors 23 each disposed in contact with and thermally connected to an outer surface of the battery container 13a; and insulation covers 17 each partially covering the battery container 13a and pressing the thermistor 23 against the battery container 13a, and having an electrical insulating property and rigidity. The insulation cover 17 is formed with a through hole 26 through which heat application means 28, 29 passes. The thermistor 23 is located at a position outside a heat application region where the through hole 26 is projected orthogonally onto a planar section 21 of the battery container 13a.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a battery module formed by connecting a plurality of unit batteries, and to a method for inspecting this battery module. [Background technology]

[0002] For example, electrolyte batteries including a positive electrode layer and a negative electrode layer capable of absorbing / releasing lithium ions are widely used as high-energy density batteries in various fields such as electric vehicles, power storage, and information devices. Known electrolyte batteries include those that use a liquid electrolyte and those that use a solid electrolyte.

[0003] A secondary battery using an electrolyte battery is composed of a battery pack consisting of multiple unit cells (electrolyte cells). This battery module can generate large amounts of power by electrically connecting the unit cells with electrode members (hereinafter referred to as bus bars) made of conductive metals such as aluminum, copper, and iron.

[0004] The battery module also has a pair of external terminals that enable the battery module to receive and transmit power, and the bus bars and the pair of module external terminals are made of insulating material, mainly made of engineering plastic, that insulates adjacent bus bars from each other and from high-voltage components including the module external terminals.

[0005] Here, the battery module is equipped with a temperature detector such as a thermistor for detecting its own temperature, and the acquired battery temperature information is used to control the charge and discharge of the battery module. In particular, battery modules installed in automobiles and the like are used in a wide range of environmental temperatures, from low to high. Furthermore, since the input / output characteristics and life characteristics of the battery are temperature-dependent, battery temperature information is essential for appropriately controlling the charge and discharge of the battery module.

[0006] In battery modules equipped with such temperature detectors, it is necessary to check whether the temperature detector is operating normally from the viewpoint of product quality. For this reason, the battery module is generally operated to increase its temperature, and the operation of the temperature detector is checked by whether this temperature change can be detected. However, this method places an electrical load on the battery module, which is not a good idea.

[0007] As a method for addressing such issues, for example, the technology described in JP 2016-9663 A (Patent Document 1) is known. In this Patent Document 1, a heat transfer plate provided in contact with the side surface of the battery is heated by an external heat source such as a heater, causing a temperature change in a thermistor attached to the upper surface of the battery, and the operation of the thermistor is confirmed from this temperature change. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-9663 Summary of the Invention [Problem to be solved by the invention]

[0009] However, Patent Document 1 has the problem of being unable to perform efficient inspections. For example, there are one or more problems, such as the need for the work process of attaching and detaching the heat transfer plate, which makes the inspection work cumbersome, the power consumption of the heat source such as a heater that heats the heat transfer plate, which increases, or the temperature rise is slow because heat is applied to the temperature detector via the heat transfer plate, which makes it time-consuming to check the operation of the temperature detector.

[0010] An object of the present invention is to provide a battery module that can be efficiently inspected without applying an electrical load to the battery module, and a method for inspecting this battery module. [Means for solving the problem]

[0011] A typical feature of the present invention is that it comprises a battery having a battery container that houses a battery element, a temperature detector that is in contact with and thermally connected to the outer surface of the battery container, and a covering member that has electrical insulation and rigidity and covers a portion of the battery container and brings the temperature detector into contact with the battery container, the covering member having an inspection through-hole through which a heat-applying means passes, and the temperature detector is positioned outside the heat-applying area, which is the projection area of ​​the inspection through-hole onto the outer surface of the battery container. [Effects of the Invention]

[0012] In the present invention, by directly heating or cooling the heat application area using a heat application means through an inspection through-hole provided in the covering member, the temperature near the temperature detector can be raised or lowered in a short time, allowing for efficient inspection. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is an external perspective view of a battery module to which the present invention is applied; [Figure 2] 2 is an exploded perspective view showing a state in which a part of the battery module shown in FIG. 1 is disassembled. FIG. [Figure 3] FIG. 1 is a cross-sectional view showing a state before an insulation cover is attached according to a first embodiment of the present invention. [Figure 4] FIG. 3 is a cross-sectional view showing the first embodiment of the present invention, illustrating an inspection state after an insulation cover is attached. [Figure 5] FIG. 10 is a cross-sectional view showing a modified example of the first embodiment of the present invention, illustrating an inspection state after the insulation cover is attached. [Figure 6] FIG. 1 is a schematic diagram of a thermistor inspection system. [Figure 7] FIG. 10 is a characteristic diagram showing the change in temperature measured by the thermistor over time after the battery container is heated. [Figure 8] 7 is a flowchart illustrating the flow of an inspection using the inspection system shown in FIG. 6. [Figure 9] FIG. 10 is a cross-sectional view showing a second embodiment of the present invention, illustrating a state before an insulation cover is attached. [Figure 10] FIG. 10 is a cross-sectional view showing a state after an insulation cover has been attached according to a third embodiment of the present invention. [Figure 11] FIG. 10 is a top view of a battery module for explaining the state of wiring attached to an insulation cover according to a fourth embodiment of the present invention. [Figure 12] FIG. 12 is an external perspective view of the battery module shown in FIG. [Figure 13] FIG. 10 is a cross-sectional view showing a state before an insulation cover is attached according to a fifth embodiment of the present invention. [Figure 14] FIG. 10 is a cross-sectional view showing a sixth embodiment of the present invention, illustrating a state before an insulation cover is attached. [Figure 15] FIG. 15 is a schematic diagram of the battery control device shown in FIG. [Figure 16] 16 is a flowchart illustrating the flow of an inspection using the inspection system shown in FIG. 15. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiment, and various modifications and application examples within the technical concept of the present invention are also included within its scope. [Example]

[0015] Fig. 1 shows a battery module according to an embodiment of the present invention as seen obliquely from above. The terms "up and down / left and right / front and back" in Fig. 1 and Fig. 2 indicate the viewing directions of the battery module shown in Fig. 1 and Fig. 2. Therefore, in the following description, when the directions "up and down / left and right / front and back" are used, the description will be based on the viewing directions shown in Fig. 1 and Fig. 2.

[0016] 1 and 2, the housing 11 constituting the battery module 10 has a generally elongated rectangular parallelepiped shape with a longitudinal dimension (front-rear direction) greater than the transverse dimensions (left-right direction) and height direction (up-down direction), and holds a plurality of unit batteries 13 (see FIG. 2) that constitute a battery group 12 (see FIG. 2). More specifically, the housing 11 holds a plurality of cell holders 14 (see FIG. 2). ), a pair of end plates 15, a pair of side plates 16, an insulation cover (inner covering member) 17, and a module cover (outer covering member) 18. As shown in FIG. 1, the end plates 15 and the side plates 16 are firmly fixed together with fixing members 19 such as fixing bolts or rivets.

[0017] The unit battery 13 contains battery elements including an electrolyte, a positive electrode layer, a negative electrode layer, etc. The electrolyte may be liquid or solid.

[0018] The cell holders 14 (see FIG. 2) are made of a resin material, such as polybutylene terephthalate (PBT). The cell holders 14 are interposed between adjacent unit batteries 13 of the multiple unit batteries 13 stacked in the front-to-rear direction, and hold each unit battery 13 by sandwiching it from both sides in the thickness direction (front-to-rear direction).

[0019] In the longitudinal direction (front-rear direction) of the plurality of unit batteries 13 that make up the battery group 12, assembled battery terminals 10P, 10N (see FIG. 2) that are external terminals of the battery module 10 are provided on a pair of cell holders 14 arranged at both ends of the battery group 13. Here, the module terminal 10P is the assembled battery positive terminal, and the module terminal 10N is the assembled battery negative terminal.

[0020] The pair of end plates 15 are metal plate-shaped members. The pair of end plates 15 are arranged on both sides of the battery group 12 in the stacking direction (front-rear direction) of the multiple unit batteries 13 that make up the battery group 12, via a pair of cell holders 14 arranged on both sides of the battery group 12. One surface of the pair of end plates 15 faces each other so as to sandwich the multiple unit batteries 13 held by the cell holders 14, and a fixing portion 15a is provided on the other surface facing outward, opposite the battery group 12.

[0021] The fixing portions 15a provided on the pair of end plates 15 are formed in a generally cylindrical shape, with a portion of the cylindrical side surface protruding toward the front or rear of the battery pack from the outer flat surface of the end plate 15. The fixing portions 15a have a bolt hole along a central axis that is parallel to the height direction (up-down direction) of the end plate 15.

[0022] The fixing portion 15a of the end plate 15 is a fixing member attachment portion for fixing the battery module 10 to an external mechanism such as a vehicle or other machine. The lower end surface of the fixing portion 15a of the end plate 15 is the support surface 11a of the housing 11 that is supported by the external mechanism.

[0023] That is, the battery module 10 can be fixed to the external mechanism by supporting the support surface 11a of the housing 11, which is the bottom surface of the fixing portion 15a of the end plate 15, with the external mechanism, and fastening the bolts inserted into the bolt holes of the fixing portion 15a by screwing them into the female threads or nuts of the external mechanism. In other words, the battery module 10 is fixed to the external mechanism with the bolts, and is supported by the external mechanism at least by the support surface 11a of the housing 11, which is the bottom surface of the fixing portion 15a of the end plate 15.

[0024] When the battery module 10 is mounted on a vehicle such as an electric vehicle or a hybrid vehicle, the external mechanism to which the battery module 10 is fixed is the vehicle body. Although not particularly limited, when the vehicle to which the battery module 10 is fixed is placed on a horizontal road surface, the length direction (front-to-back direction) and width direction (left-to-right direction) of the housing 11 of the battery module 10 are generally parallel to the horizontal direction, and the height direction (up-down direction) of the housing 11 of the battery module 10 is generally parallel to the vertical direction. Furthermore, in this state, the support surface 11a of the housing 11 is generally parallel to the horizontal plane.

[0025] The pair of side plates 16 are arranged via cell holders 14 on both sides in the width direction (left-right direction) of the multiple unit batteries 13 that make up the battery group 12. The pair of side plates 16 are roughly rectangular plate-shaped metal members, and are arranged on both sides in the width direction (left-right direction) of the housing 11 so as to face each other.

[0026] The pair of side plates 16 are roughly rectangular, with the stacking direction (front-to-back direction) of the multiple unit batteries 13 that make up the battery group 12 being the long side direction, i.e., longitudinal direction, and the height direction (up-down direction) of the multiple unit batteries 13 that make up the battery group 12 being the short side direction, i.e., lateral direction.

[0027] Both longitudinal ends of the pair of side plates 16 are fastened to the pair of end plates 15 by fastening members 19 such as rivets or bolts. Both lateral ends of the pair of side plates 16 are engaged with concave grooves provided in the cell holder 14.

[0028] The insulation cover 17 is a plate-shaped member made of an electrically insulating resin such as PBT and having a predetermined rigidity, and is disposed opposite the upper end surface of the battery container 13a on which the cell positive terminal 13p and the cell negative terminal 13n of the unit battery 13 are provided. Note that the predetermined rigidity means a rigidity that does not cause unnecessary deformation when the insulation cover 17 is attached to the battery module 10. In other words, it is sufficient for the insulation cover 17 to have sufficient rigidity.

[0029] The insulation cover 17 has openings that expose the upper end surfaces of the cell positive terminals 13p and cell negative terminals 13n of the multiple unit batteries 13, and partition walls that provide insulation between the cell positive terminals 13p and cell negative terminals 13n of adjacent unit batteries 13 and between adjacent bus bars 2.

[0030] The partition wall of the insulation cover 17 is provided to surround the cell positive terminal 13p, the cell negative terminal 13n, and the bus bar 20 of the unit battery 13. The insulation cover 17 also accommodates various electrical wiring connected to the battery group 12 and an electronic circuit board that constitutes a battery control device (not shown).

[0031] The electronic circuit board (not shown) is disposed between the insulation cover 17 and the module cover 18, i.e., on the opposite side of the insulation cover 17 from the battery group 12 in the height direction of the housing 11, and is electrically connected to a plurality of bus bars 20 and a temperature sensor (thermistor) (not shown) for detecting the temperature of the unit battery 1 via connecting conductors such as lead wires or printed wiring.

[0032] In FIG. 2, the battery module 10 mainly comprises module terminals 10P, 10N (see FIG. 2) which are external terminals, a battery group 12 including a plurality of unit batteries 13, and a bus bar 20 which electrically and mechanically connects the plurality of unit batteries 13 of the battery group 12 and electrically and mechanically connects the battery group 12 to the module terminals 10P, 10N.

[0033] The battery group 12 is constructed by stacking flat rectangular unit batteries 13, i.e., thin hexahedral or rectangular unit batteries 13 whose thickness is smaller than their width and height, in the longitudinal direction (front-to-back direction). The unit batteries 13 are rectangular lithium-ion batteries and include a flat rectangular battery container 13a, an electrode group (not shown) housed inside the battery container 13a, an electrolyte solution or a solid electrolyte sheet, and a pair of cell terminals 13p, 13n connected to the electrode group and located on the upper end surface of the battery container 13a in the height direction. As described above, the cell terminal 13p is the positive terminal, and the cell terminal 13n is the negative terminal.

[0034] The cell terminals 13p, 13n of the unit battery 13 have a three-dimensional, roughly rectangular parallelepiped shape that protrudes in the height direction from the upper end surface of the battery container 13a. The cell terminals 13p, 13n and the battery container 13a, and the battery container 13a and the electrode group are electrically insulated by resin insulating members. The multiple unit batteries 13 that make up the battery group 12 are stacked in such a way that the cell positive terminal 13p of one adjacent unit battery 13 and the cell negative terminal 13n of the other adjacent unit battery 13 are alternately rotated 180° in the stacking direction (front-to-back direction).

[0035] The busbars 20 are connecting conductors that electrically and mechanically connect the multiple unit batteries 13 of the battery group 12 and also electrically and mechanically connect the battery group 12 to the module terminals 10P, 10N. The busbars 20 that electrically and mechanically connect the multiple unit batteries 13 of the battery group 12 are multiple busbars 20A that electrically and mechanically connect the unit batteries 13, and are joined by welding to the upper end surfaces of the cell terminals 13p, 13n of the multiple unit batteries 13 of the battery group 12 that are exposed through the openings in the insulation cover 17.

[0036] Of a pair of unit batteries 13 adjacent to each other in the stacking direction, the cell positive terminal 13p of one unit battery 13 and the cell negative terminal 13n of the other unit battery 13 are electrically connected by a bus bar 20A to form a battery group 12 in which all unit batteries 13 are electrically connected in series.

[0037] The bus bars 20 connecting the battery group 12 to the module terminals 10P, 10N are a pair of bus bars 20B arranged at both ends in the stacking direction of the unit batteries 13 of the battery group 12. One of the pair of bus bars 20B, 20B1, is electrically and mechanically connected to the cell positive terminal 13p of one of the pair of unit batteries 13 arranged at both ends in the stacking direction of the multiple unit batteries 13. The other of the pair of bus bars 20B, 20B2, is electrically and mechanically connected to the cell negative terminal 13n of the other of the pair of unit batteries 13 arranged at both ends in the stacking direction of the multiple unit batteries 13.

[0038] One end of one 20B1 of the pair of bus bars 20B is joined by welding to the upper end surface of the cell positive terminal 13p of the unit battery 13, and the other end is fastened by a fastening member such as a rivet or bolt to a module positive terminal 10P arranged on one side of the battery group 10 in the stacking direction of the unit batteries. One end of the other 20B2 of the pair of bus bars 20B is joined by welding to the upper end surface of the cell negative terminal 13n of the battery group 13, and the other end is fastened by a fastening member such as a rivet or bolt to a module negative terminal 10N arranged on the other side of the battery group 12 in the stacking direction of the unit batteries 13.

[0039] Returning to Fig. 1, module cover 18 is a plate-like member made of electrically insulating resin such as PBT, and is arranged at the upper end of housing 11 on the opposite side of housing 11 from battery group 12 in the height direction (vertical direction) of housing 11 so as to cover insulation cover 17 and the electronic circuit board. Terminal cover 18a is provided at a position on module cover 18 corresponding to module terminals 10P, 10N so as to cover the upper parts of module terminals 10P, 10N. Module cover 18 is fixed to the top of insulation cover 17 by engaging engagement claws 17b provided on frame portion 17a of insulation cover 17 with the side edges.

[0040] As will be described later, in this embodiment, inspection is performed after the battery module 10 has been assembled and before it has been sealed with the module cover 18.

[0041] The battery module 10 configured as described above has module terminals 10P, 10N electrically connected to an external generator or motor via an inverter device, which is a power conversion device, so that power can be exchanged between the battery module 10 and an external generator or motor via the inverter device.

[0042] Next, an embodiment of the present invention will be described. Fig. 3 shows a configuration for explaining the concept of an embodiment of the present invention, showing the state before the temperature detector is inspected. In this state, most of the components of the battery module 10 are assembled as shown in Fig. 2, and the battery module 10 is ready for inspection, and is in a state before the module cover 18 is sealed.

[0043] 3, as described above, the upper surface of the battery container 13a constituting the unit battery 13 has a cell positive terminal 13p and a cell negative terminal 13n, and a flat area 21 in which a temperature detector (hereinafter referred to as a thermistor) is disposed is formed between the cell positive terminal 13p and the cell negative terminal 13n. The battery container 13a is formed from a metal plate, which facilitates temperature transfer to the thermistor disposed in the flat area 21. Note that a thermistor may be provided for each battery container 13a, or a thermistor may be provided for each group of multiple battery containers 13a.

[0044] An insulation cover 17 is attached and fixed to the upper side of the side plates 16 that are integrated and sandwich the battery pack 12. The insulation cover 17 is formed with a terminal storage section 22 that stores the cell positive terminal 13p and the cell negative terminal 13n, and when the insulation cover 17 is attached to the battery pack 12, the cell positive terminal 13p and the cell negative terminal 13n are stored in this terminal storage section 22.

[0045] A storage recess 24 for storing the thermistor 23 is formed on the surface of the insulation cover 17 facing the battery group 12, and a spring means 25 having the function of pressing the thermistor 23 against the flat area 21 on the upper surface of the battery container 13a is disposed in this storage recess 24. The spring means 25 can be in various forms (for example, a coil spring, a leaf spring, etc.).

[0046] In this way, by storing the thermistor 23 in the insulation cover 17, the thermistor 23 and the insulation cover 17 can be handled together. This improves ease of handling during assembly, and because the inspection through-hole 26, which will be described later, is also formed in the insulation cover 17, the positional relationship between the thermistor 23 and the inspection through-hole 26 can be accurately determined, and further, wiring can be easily routed.

[0047] As shown by the dashed line, the thermistor 23 can be attached to the flat area 21 of the battery container 13a and pressed into contact with it by a resilient means 25 provided on the insulation cover 17. In either case, in this embodiment, the thermistor 23 contacts the flat area 21 of the battery container 13a to ensure a heat transfer path.

[0048] Therefore, when the insulation cover 17 is attached, the thermistor 23 is pressed against the flat area 21 on the upper surface of the battery container 13a by the elastic means 25, thereby forming a heat transfer path. As a result, the heat of the flat area 21 is detected by the thermistor 23 and used to control the charge and discharge of the battery module 10.

[0049] The thermistor 23 is pressed against the flat area 21 by the elastic means 25 to form a heat transfer path, but the contact state between the thermistor 23 and the flat area 21 of the battery container 13a may change for some reason. For example, if the thermistor 23 makes contact with the flat area 21 in a partially abutting state, the heat transfer area decreases, causing a problem in which the detection accuracy of the thermistor decreases.

[0050] It is also possible that the thermistor 23 may malfunction or develop an abnormality during the assembly process, and completing the assembly in this state may result in the battery module 10 itself becoming a defective product.

[0051] For this reason, it is necessary to efficiently inspect with a simple configuration whether the thermistor 23 is correctly attached and whether the thermistor itself is malfunctioning or abnormal.

[0052] Therefore, this embodiment is characterized in that the inspection through-hole 26 is formed in the insulation cover 17 adjacent to the thermistor 23 attached to the insulation cover 17 when the insulation cover 17 is viewed from above. Therefore, the inspection through-hole 26 and thermistor 23 are inevitably arranged adjacent to each other with a predetermined distance maintained between them.

[0053] Then, in a state where the insulation cover 17 is assembled to the battery container 13a (see FIG. 4), a heat-applying area 27 is virtually formed in the flat area 21 of the battery container 13a, where the inspection through-hole 26 is orthogonally projected onto the flat area 21 when viewed in a direction perpendicular to the flat area 21 of the battery container 13a. Here, in this embodiment, the inspection through-hole 26 is circular, and therefore the heat-applying area 27 is also formed in a circular shape. Note that the inspection through-hole 26 is not limited to a circle, and may be rectangular, elliptical, or a polygon with pentagons or more sides, and the key is that it is sufficient that it has a function that allows a heat-applying means, which will be described later, to pass through.

[0054] Therefore, when the thermistor 23 is placed on the flat area 21, the thermistor 23 and the heat-imparting area 27 do not overlap, and the positional relationship between the thermistor 23 and the inspection through-hole 26 formed in the insulation cover 17 is reflected as is. For this reason, as will be described later, the thermistor 23 is positioned outside the heat-imparting area 27, and contact between the heat-imparting means and thermistor 23 can be avoided. If the heat-imparting means and thermistor 23 were to come into direct contact, the state of contact between the thermistor 23 and the flat area 21 of the battery container 13a would not be reflected, which could result in an inaccurate inspection.

[0055] Next, a specific method for inspecting the thermistor 23 will be described with reference to Figures 4 and 5. The difference between Figures 4 and 5 is that the heat application means is different, but the configuration is the same.

[0056] 4, a fully assembled battery module 10 is prepared before the module cover 18 is attached. In this state, the insulation cover 17 is attached to the battery container 13a, and the cell positive terminal 10P and the cell negative terminal 13n are housed in the terminal housing portion 22 of the insulation cover 17. In this state, the thermistor 23 is pressed against the flat area 21 of the battery container 13a by the elastic means 25 and placed thereon.

[0057] Next, the temperature adjustment member 28, which is a heat applying means, is moved through the inspection through-hole 26 until it comes into contact with the heat applying region 27. For this reason, the inspection through-hole 26 is formed with a size and shape that allows the temperature adjustment member 28 to pass through. In addition, in this embodiment, the temperature adjustment member 28 uses a resistance heating element and is managed to apply a constant amount of thermal energy to the battery container 13a. This makes it possible to continue to apply a stable amount of heat directly to the planar region 21 of the battery container 13a.

[0058] Furthermore, by applying a constant amount of heat energy, it is possible to obtain accurate temperature changes. In this embodiment, the temperature difference is calculated by detecting the temperatures before and after a predetermined time has elapsed, so it is important to apply a constant amount of heat energy for at least the predetermined time.

[0059] The heat imparted to the heat-imparting region 27 is transmitted through the flat region 21 of the battery container 13a to the thermistor 23, and the thermistor 23 changes its electrical resistance value in response to the transmitted heat, enabling it to measure the temperature. In other words, the temperature can be measured by converting the electrical resistance value detected by the thermistor 23 into a temperature using a conversion table.

[0060] In this manner, in this embodiment, thermal energy can be applied directly to the battery container 13a, so a small amount of thermal energy is sufficient, and power consumption can be kept low. Furthermore, since the thermistor 23 and the temperature control member 28, which serves as the heat source, are located close to each other, heat is quickly transferred to the thermistor 23, allowing the operation of the thermistor to be checked in a short time. Furthermore, the temperature control member 28 is inserted into the inspection through-hole 26 formed in the insulation cover 17, heat is applied, and once the inspection is complete, the temperature control member 28 is simply pulled out, simplifying the inspection process.

[0061] If the electrical resistance of the thermistor 23 does not change even when heat is applied, it can be detected that a malfunction or abnormality has occurred in the thermistor 23 itself. Furthermore, it can be detected whether good contact is being maintained between the thermistor 23 and the flat surface area 21 of the battery container 13a based on the amount of temperature change within a predetermined time. A method for determining contact between the thermistor 23 and the flat surface area 21 of the battery container 13a will be described later.

[0062] The temperature control member 28 described above uses a resistance heating element to apply "heat" to the battery container 13a, but it is also possible to apply "cold" to the battery container 13a using a Peltier element instead of a resistance heating element. In this case, the inspection method is the same as the method described above.

[0063] In this embodiment, it is important that the thermistor 23 is not exposed to the heat application area 27 formed by the inspection through-hole 26 so that there is no mechanical interference between the thermistor 23 and the temperature adjustment member 28. Furthermore, to reduce the amount of thermal energy and shorten the inspection time, it is necessary that the thermal resistance between the thermistor 23 and the heat application area 27 is small. For this reason, it is important that the thermistor 23 is installed near the heat application area 27.

[0064] Therefore, the positions of thermistor 23 and inspection through-hole 26 should be determined so as to satisfy these conditions. In this embodiment, as shown in Fig. 3, by bringing thermistor 23 and inspection through-hole 26 as close as possible, inspection through-hole 26 and thermistor 23 are inevitably positioned adjacent to each other with a predetermined distance maintained.

[0065] Next, another example of the heat applying means will be described. In Fig. 5, a laser irradiation device 29 is used as the heat applying means, which is different from the embodiment in Fig. 4.

[0066] 5, a fully assembled battery module 10 is prepared before the module cover 18 is attached. In this state, the insulation cover 17 is attached to the battery container 13a, and the cell positive terminal 10P and the cell negative terminal 13n are housed in the terminal housing portion 22 of the insulation cover 17. In this state, the thermistor 23 is pressed against the flat area 21 of the battery container 13a by the elastic means 25 and placed thereon.

[0067] Next, the laser irradiation member 29, which is heat applying means, is moved so that it is positioned on the upper surface of the inspection through-hole 26. For this reason, the inspection through-hole 26 is formed in a size and shape that allows the laser light 30 from the laser irradiation member 29 to reach the flat area 21 without interfering with the insulation cover 17 or the like. Furthermore, in this embodiment, the laser irradiation member 29 is controlled so that a constant amount of light energy is applied to the battery container 13a. This allows stable light energy to be continuously applied directly to the flat area 21 of the battery container 13a in a non-contact manner.

[0068] The laser light 30 applied to the heat application area 27 is converted into heat, which travels through the flat area 21 of the battery container 13a to the thermistor 23, and the resistance of the thermistor 23 changes in response to the transferred heat, allowing the temperature to be measured. In other words, the output voltage from the thermistor 23 can be converted using a conversion table to measure the temperature.

[0069] As described above, in this embodiment, light energy can be applied directly to the battery container 13a, so a small amount of light energy is sufficient, and power consumption can be kept low. Furthermore, since the thermistor 23 and the irradiation position of the laser irradiation member 29, which serves as the heat source, are close to each other, heat is quickly transferred to the thermistor 23, making it possible to check the operation of the thermistor in a short time. Furthermore, the inspection process is simplified because the laser irradiation member 29 is moved to the top surface of the inspection through-hole 26 formed in the insulation cover 17, laser light 30 is irradiated, and the laser irradiation member 29 is simply moved once the inspection is complete.

[0070] If thermistor 23 does not generate an output voltage even when heated by laser light 30, it can be detected that a failure or abnormality has occurred in thermistor 23. Furthermore, it can be detected whether good contact is being maintained between thermistor 23 and flat area 21 of battery container 13a based on the amount of temperature change within a predetermined time.

[0071] Next, the configuration of an inspection system for the thermistor 23 and a method for inspecting whether good contact is maintained between the thermistor 23 and the flat area 21 of the battery container 13a will be described.

[0072] 6 shows the configuration of an inspection system required for the inspection. In FIG. 6, the configurations and positions of the battery container 13a, temperature adjustment member 28, and thermistor 23 are the same as those shown in FIG.

[0073] In FIG. 6, a temperature adjustment member control unit 32 provided in an inspection control device 31 controls the heating of a temperature adjustment member 28 via a wiring 32L, controlling the heating start time, heating time, heating end time, amount of heating energy, etc. The output voltage of the thermistor 23 generated by this heating is input to a temperature measurement unit 33 provided in the inspection control device 31 via a wiring 23L at predetermined time intervals and converted into temperature information. The temperature information can be obtained using an "output voltage-temperature table." This temperature information is stored in a RAM area (not shown) of the inspection control device 31 at predetermined time intervals.

[0074] The inspection control device 31 is equipped with a temperature change value calculation unit 34, which calculates the degree of change (difference) in the temperature of the thermistor 23 over a predetermined period of time, and this is input as an actual temperature change value (ΔTact) to a subsequent diagnosis unit 36. This actual temperature change value (ΔTact) can be obtained by reading out temperature information stored in the RAM area.

[0075] That is, it can be obtained by subtracting temperature information (T1) stored at a certain time from temperature information (T2) stored at a time a predetermined time after the time when the temperature information (T1) was obtained. The actual temperature change value (ΔTact) will be described with reference to FIG. 7. In this embodiment, once the temperature information (T1) and the temperature information (T2) are obtained, the temperature adjustment member control unit 32 is instructed to stop heating by the temperature adjustment member 28.

[0076] The inspection control device 31 includes a memory unit 35 made up of a flash ROM or the like, which stores a temperature change threshold value (ΔTref), which is used as a reference value for determining whether good contact is maintained between the thermistor 23 and the flat area 21 of the battery container 13a. This temperature change threshold value (ΔTref) is input to a subsequent diagnostic unit 36. The temperature change threshold value (ΔTref) will be described with reference to FIG. 7.

[0077] When the diagnostic unit 36 ​​of the inspection control device 31 determines whether good contact is maintained between the thermistor 23 and the flat area 21 of the battery container 13a, the result is sent to the output unit 37 and displayed on a display or the like, so that the operator can understand the diagnostic result of the output unit 37.

[0078] If good contact is maintained between the thermistor 23 and the flat surface area 21 of the battery container 13a, the worker attaches the module cover 18 and completes the assembly work. On the other hand, if good contact is not maintained between the thermistor 23 and the flat surface area 21 of the battery container 13a, the worker corrects the attachment state of the thermistor 23 to the insulation cover 17, redoes the assembly, and performs the same inspection again.

[0079] FIG. 7 explains how to calculate the actual temperature change value (ΔTact) and the temperature change threshold value (ΔTref). The horizontal axis represents the elapsed time, and the vertical axis represents the temperature measured by the thermistor 23. The solid line represents the actual temperature, and the dashed line represents the temperature when the contact state between the thermistor 23 and the flat area 21 is intentionally set poorly. The temperature indicated by the dashed line is used to calculate the temperature change threshold value (ΔTref) described above.

[0080] When heating begins at time (t0) using temperature adjustment member 28, the temperature of thermistor 23 rises as shown by the solid line, and temperature information measured by the thermistor at time (t1) is obtained. The actual temperature at this time is temperature (T1). Then, a predetermined time later at time (t2), temperature information measured by the thermistor is obtained again. The actual temperature at this time is temperature (T2). Then, the temperature (T1) at time (t1) is subtracted from the temperature (T2) at time (t2) to obtain the actual temperature change value (ΔTact).

[0081] On the other hand, the temperature change threshold (ΔTref) is determined in advance by experiment or simulation. In this case, as shown by the dashed line, the temperature change threshold (ΔTref) is determined assuming a failing contact state (abnormal contact state) in which the contact state between the thermistor 23 and the flat area 21 of the battery container 13a is slightly lower than a passing contact state (normal contact state) in which the temperature information from the thermistor 23 is deemed to be sufficiently reliable.

[0082] Therefore, if the actual temperature change value (ΔTact) is greater than the temperature change threshold value (ΔTref), it is considered to be pass (normal), and if the actual temperature change value (ΔTact) is less than the temperature change threshold value (ΔTref), it is considered to be fail (abnormal).

[0083] When heating is started at time (t0) by the temperature adjustment member 28 under the unacceptable contact state, the temperature of the thermistor 23 rises as shown by the dashed line, but the slope is smaller than that of the solid line. Then, temperature information measured by the thermistor 23 at time (t1) is obtained. The actual temperature at this time is temperature (T1ref). Then, at time (t2) after a predetermined time, temperature information measured by the thermistor 23 is obtained again. The actual temperature at this time is temperature (T2ref). Then, the temperature (T1ref) at time (t1) is subtracted from the temperature (T2ref) at time (t2) to obtain a temperature change threshold (ΔTref). This temperature change threshold (ΔTref) serves as a judgment reference value and is stored in flash ROM.

[0084] Therefore, by determining the relationship between the temperature change threshold (ΔTref) and the actual temperature change value (ΔTact), it is possible to determine whether good contact is maintained between the thermistor 23 and the flat area 21 of the battery case 13a. Once this determination is made, the test ends at time (t3).

[0085] It is preferable to stop heating the temperature adjustment member 28 after measuring the actual temperatures (T1) and (T2) and storing them in the RAM area before the step of determining the contact state (step S16) described later. This makes it possible to avoid unnecessary power consumption and to prevent thermistor 23 from being heated more than necessary.

[0086] Here, if the time required from time (t0) to time (t1) and the time required from time (t1) to time (t2) are set to the same length, the temperature change measurement conditions will match, allowing for accurate judgment. Alternatively, the temperature change rate may be determined by calculating (T2-T1) / (t2-t1). Using the temperature change rate in this way reduces the influence of variations, etc., allowing for more accurate judgment.

[0087] Next, a specific control flow executed by the inspection control device 31 will be described with reference to Fig. 8. This control flow is started when the inspection is to be performed (when an instruction to start inspection is issued from the inspection control device), and is thereafter executed at predetermined time intervals.

[0088] <Step S10> In step S10, the temperature adjustment member 28 is brought into contact with the flat area 21 of the battery container 13a at time (t0) in Fig. 7, and heating is initiated. Once heating is initiated, the process proceeds to step S11.

[0089] <Step S11> In step S11, at time (t1) when a predetermined time has elapsed since time (t0) in Fig. 7, temperature information (T1) is obtained from the thermistor 23 and stored in a predetermined area of ​​RAM. Once the temperature information (T1) is obtained, the process proceeds to step S12.

[0090] <Step S12> In step S12, at time (t2) when a predetermined time has elapsed since time (t1) in Fig. 7, temperature information (T2) is obtained from thermistor 23 and stored in a predetermined area of ​​RAM. Once temperature information (T2) is obtained, the process proceeds to step S13.

[0091] <Step S13> In step S13, since the temperature information (T1) was detected in step S11, the temperature information (T2) was detected in step S12, and the first temperature (T1) and the second temperature (T2) have already been stored in the RAM area, there is no need to heat the temperature adjustment member 28, so heating of the temperature adjustment member 28 is stopped. Once heating of the temperature adjustment member 28 has been stopped, the process proceeds to step S14. This makes it possible to avoid unnecessary power consumption and to prevent thermistor 23 from being heated more than necessary.

[0092] <Step S14> In step S14, the temperature information (T1) stored in the RAM area and the temperature information (T2) stored in the RAM area are read out, and the actual temperature change value (ΔTact) is calculated and stored in a new RAM area. The calculation formula is "ΔTact = T2 - T1". Once the actual temperature change value (ΔTact) is calculated, the process proceeds to step S14.

[0093] <Step S15> In step S15, the temperature change threshold value (ΔTref) stored in the flash ROM for comparison and judgment to be executed in the next step is read out and stored in the RAM area. After the temperature change threshold value (ΔTref) is read out, the process proceeds to step S16.

[0094] <Step S16> In step S16, the actual temperature change value (ΔTact) calculated in step S14 is compared with the temperature change threshold value (ΔTref) calculated in step S15. If the actual temperature change value (ΔTact) is large, the process proceeds to step S17, and if the actual temperature change value (ΔTact) is small, the process proceeds to step S18.

[0095] A large actual temperature change value (ΔTact) indicates that heat from the temperature adjustment member 28 is being transferred well to the thermistor 23. In other words, this means that the contact state between the thermistor 23 and the flat area 21 of the battery container 13a is normal.

[0096] On the other hand, if the actual temperature change value (ΔTact) is small, it indicates that the heat from the temperature adjustment member 28 is not being transferred well to the thermistor 23. In other words, it means that the contact state between the thermistor 23 and the flat area 21 of the battery container 13a is abnormal.

[0097] <Step S17> In step S16, it is determined that the contact state between the thermistor 23 and the flat area 21 of the battery container 13a is good, so in step S17, a display indicating that the contact state is normal (OK display) is executed on the display device of the output unit 37. Once the display indicating that the contact state is normal (OK display) is executed, the process proceeds to step S19.

[0098] <Step S18> On the other hand, since it is determined in step S16 that the contact state between the thermistor 23 and the flat area 21 of the battery container 13a is not good, in step S17, a display indicating an abnormality (NG display) is executed on the display device of the output unit 37. After executing a display indicating an abnormality (NG display), the process exits to END and ends. In this case, since good contact is not maintained between the thermistor 23 and the flat area 21 of the battery container 13a, the worker corrects the attachment state of the thermistor 23 on the insulation cover 17, reassembles it, and executes the same inspection again.

[0099] <Step S19> In step S19, it is determined that good contact is maintained between the thermistor 23 and the flat area 21 of the battery container 13a, and the internal resistance of the battery group 12 is finally measured to check the resistance value. When this check is complete, the process skips to END and ends. In this case, it is determined that good contact is maintained between the thermistor 23 and the flat area 21 of the battery container 13a, and the internal resistance of the battery group 12 is normal, so the worker attaches the module cover 18 to the insulation cover 17, completing the assembly of the battery module 10.

[0100] The order of the process of determining the actual temperature change value (ΔTact) in step S14 and the process of determining the temperature change threshold value (ΔTref) in step S15 may be reversed. Also, the process of ending heating in step S13 may be executed between steps S14 and S18.

[0101] Furthermore, as described above, the "thermistor inspection" in steps S10 to S18 and the "battery resistance inspection" in step S19 can be carried out completely separately and independently, thereby enabling the inspection work to be carried out accurately.

[0102] As described above, in this embodiment, the battery 13 includes a battery container 13a that houses a battery element, a thermistor 23 that is in contact with and thermally connected to the outer surface of the battery container 13a, and a The battery container 13a has an insulating cover 17 that has electrical insulation and rigidity and covers a portion of the battery container 13a and presses the thermistor 23 against the battery container 13a. The insulating cover 17 has an inspection through-hole 26 through which heat-applying means 28, 29 pass, and the thermistor 23 is positioned outside the heat-applying area when the inspection through-hole 26 is projected onto the flat surface 21 of the battery container 13a.

[0103] According to this, by directly heating or cooling the heat application area with heat application means 28, 29 through the inspection through-hole 26 provided in the insulation cover 17, the temperature near the thermistor 23 can be raised or lowered in a short time, allowing for efficient inspection.

[0104] Incidentally, the inspection through-hole 26 may be closed by a lid (not shown) provided on the insulation cover 17, or the insulation cover 17 may not have a lid and may be shielded from the outside by the module cover 18.

[0105] Furthermore, an inspection through-hole is also provided in the module cover 18 facing the insulation cover 17, and after the module cover 18 is attached, it is possible to perform an inspection by applying heat to the battery container 13 using a heat applying means through the inspection through-holes formed in the module cover 18 and the insulation cover 17. This allows inspection to be performed after the assembly of the battery module 10 is complete. [Example]

[0106] Next, a second embodiment of the present invention will be described. Note that the same reference numerals as in Fig. 3 indicate components with the same functions, and their explanation will be omitted if unnecessary.

[0107] A feature of this embodiment is that a heat application mark 38 is provided in the heat application area 27. In the heat application area 27 corresponding to the inspection through-hole 26, there is a location where heat is best applied. For example, in terms of heat transfer efficiency, this is the location closest to the thermistor 23.

[0108] In FIG. 9 , a circular heat-application area 27 formed on the flat area 21 of the battery container 13a has a heat-application mark 38 formed at a location closest to the thermistor 23 placed on the flat area. The heat-application mark 38 is selected from, for example, a sinkhole, a dent, a protrusion, and a colored coating. The sinkhole, dent, and protrusion are preferably formed integrally with the flat area 21 by deforming the flat area 21. This is because the presence of the heat-application mark 38 can reduce the inhibition of heat conduction to the thermistor 23 compared to a structure in which the heat-application mark 38 is formed of a different material from the flat area 21. Another advantage is that the processing cost of the heat-application mark 38 can be kept low. The provision of such a heat-application mark 38 facilitates the positioning of the temperature adjustment member 28 and simplifies the inspection process.

[0109] Furthermore, when using laser light as the heat application means, the temperature rise can be accelerated by painting the heat application mark 38 black. In this case, the laser irradiation member 29 is simply placed on the upper outside of the insulation cover 17, so there is no need to insert the temperature control member 28 into the inspection through-hole 26, and the inspection work can be simplified. [Example]

[0110] Next, a third embodiment of the present invention will be described. Note that the same reference numerals as in Fig. 3 indicate components with the same functions, and their explanation will be omitted if unnecessary.

[0111] The present embodiment is characterized in that a protective sheet 39 is provided on the flat area 21 on the upper surface of the battery container 13a, but the protective sheet 39 is not provided on the heat application area 27.

[0112] In FIG. 10 , a protective sheet 39 is attached to the flat area 21 of the battery container 13a for insulation and protection. This protective sheet 39 is laid on the flat area 21 of the battery container 13a except for the areas surrounding the cell positive terminal 13p, the cell negative terminal 13n, and the thermistor 23. This insulates and protects the upper surface of the battery container 13a. However, the protective sheet 39 is not laid on the heat application area 27 corresponding to the inspection through-hole 26 so as not to reduce heat transfer efficiency. Therefore, the protective sheet 39 does not interfere with heating of the heat application area 27 by the temperature adjustment member 28 or the laser irradiation member 29. In this way, the protective sheet 39 does not impede heat transfer, which can improve inspection accuracy and shorten inspection time. [Example]

[0113] Next, a fourth embodiment of the present invention will be described. Note that the same reference numerals as in Figures 1 and 2 denote components with the same functions, and their explanation will be omitted if unnecessary.

[0114] A feature of this embodiment is that the lead wires of the thermistor 23 are placed on the upper surface of the insulation cover 17, that is, on the surface opposite the battery pack 12. Unlike the insulation cover 17 shown in Fig. 2, the insulation cover 17 of this embodiment is formed in a plate shape with a flat portion overall, and the battery pack 12 is covered by the insulation cover 17.

[0115] 11 and 12 , an opening 40 with a predetermined size is formed at one end of the insulation cover 17. The insulation cover 17 is plate-shaped with a generally flat portion and extends longitudinally along the stacking direction of the battery groups 12. The battery groups 12 are configured to be covered by the insulation cover 17.

[0116] Opening 40 is opened in a direction perpendicular to the stacking direction of battery pack 12, and a battery voltage detection terminal holder 41 and a thermistor voltage detection terminal holder 42 made of synthetic resin are exposed through opening 40. A lid 43, also made of synthetic resin, is attached to opening 40 so as to cover the opening except for battery voltage detection terminal holder 41 and thermistor voltage detection terminal holder 42.

[0117] A battery voltage detection wire accommodating section 45 that accommodates a battery voltage detection wire 44, which is a signal lead-out wire, is attached to battery voltage detection terminal holder 41, and similarly, a thermistor voltage detection wire accommodating section 47 that accommodates a thermistor voltage detection wire 46, which is a signal lead-out wire, is attached to thermistor voltage detection terminal holder 42. In addition, battery voltage detection wire 44 is connected to socket 48, and thermistor voltage detection wire 46 is also connected to socket 49.

[0118] The sockets 48 and 49 are fixed to the upper surface of the insulation cover 17 by suitable fixing means (bolts, adhesive, engagement mechanism, etc.). The socket 48 is connected to a battery control device provided in the battery module 10, and the socket 49 is connected to the inspection control device 31 (see FIG. 6).

[0119] As explained above, the insulation cover 17 extends along the stacking direction (longitudinal direction) of the battery packs 12, and so the inspection through holes 26 are also formed along this direction. The inspection through holes 26 are formed in two consecutive rows intermittently near both end faces of the insulation cover 17 in the lateral direction.

[0120] Between these two rows of inspection through holes 26, the above-mentioned opening 40, battery voltage detection terminal holder 41, thermistor voltage detection terminal holder 42, lid portion 43, battery voltage detection wire 44, battery voltage detection wire accommodating portion 45, thermistor voltage detection wire 46, thermistor voltage detection wire accommodating portion 47, and sockets 48, 49 are arranged.

[0121] By adopting the arrangement shown in FIGS. 11 and 12, the upper surface of the insulation cover 17 can be used efficiently. [Example]

[0122] In the embodiment described above, heat is applied to the flat area 21 on the upper surface of the battery container 13a from outside the insulation cover 17, but a temperature control member can also be disposed directly on the flat area 21 on the upper surface of the battery container 13a. Next, a fifth embodiment of the present invention will be described. Note that the same reference numerals as in Figure 3 indicate components with the same functions, and descriptions will be omitted unless necessary.

[0123] 13, a temperature adjustment member 50 is attached in a heat-transferable manner at a position corresponding to the heat application region 27 shown in Fig. 3. Although the temperature adjustment member 50 is exemplarily placed at a position corresponding to the heat application region 27, the point is that as long as there is no mechanical contact between the temperature adjustment member 50 and the thermistor 23, it is possible to determine whether the contact state between the thermistor 23 and the flat region 21 is good or bad, so it does not have to be the heat application region 27. However, it is preferable to place them as close as possible.

[0124] The temperature control member 50 is made of a heating element with electrical resistance, and can be one that uses nichrome wire, a PTC element, or a semiconductor element. Needless to say, other heating elements can also be used, and a Peltier element that provides cold or heat can also be used.

[0125] This temperature adjustment member 50 remains disposed in the flat area 21 on the upper surface of the battery container 13a even when the assembly of the battery module 10 is complete. Therefore, by connecting the wiring 51 of the thermistor 23 and the wiring of the temperature adjustment member 50 to an inspection control device 53, it is possible to obtain the same effects and advantages as those of the above-described embodiment. Here, the inspection control device 53 is the same as the inspection control device 31 shown in Fig. 6, and the method for determining whether the thermistor 23 has come into contact is also the same as the control flow shown in Fig. 8.

[0126] In this manner, in this embodiment, thermal energy can be directly applied to the battery container 13a by the temperature adjustment member 50, so a small amount of thermal energy is sufficient and power consumption can be kept low. Also, since the thermistor 23 and the temperature adjustment member 50 are close to each other, heat is quickly transferred to the thermistor 23, making it possible to check the operation of the thermistor in a short time.

[0127] If thermistor 23 does not generate an output voltage even when heat is applied by temperature adjustment member 50, it can be detected that a failure or abnormality has occurred in thermistor 23. Furthermore, it can be detected whether good contact is being maintained between thermistor 23 and flat area 21 of battery container 13a based on the amount of temperature change within a predetermined time. [Example]

[0128] In the fifth embodiment described above, the inspection control device 53 provided externally is configured to determine whether the contact state between the thermistor 23 and the flat area 21 is good or bad. However, it is also possible to determine whether the contact state between the thermistor 23 and the flat area 21 is good or bad on-board using a battery control device provided in the battery module 10 instead of the inspection control device 53. Note that the same reference numbers as in Fig. 13 indicate components with the same functions, and descriptions will be omitted if unnecessary.

[0129] 14, the battery control device 54 (which can also be referred to as a heat application control device) is disposed between the insulation cover 17 and the module cover 18. In other words, the battery control device 54 is disposed on the opposite side of the insulation cover 17 from the battery group 12 (see FIG. 2) in the height direction of the housing 11 (see FIG. 1), and is electrically connected to the multiple bus bars 20 (see FIG. 2), thermistor 23, temperature adjustment member 50, etc. via connecting conductors such as lead wires and printed wiring. The battery control device 54 can be attached to the insulation cover 17 or the module cover 18.

[0130] The battery control device 54 has a function for controlling the charging and discharging of the battery module 10, but this is not relevant to the present invention and therefore will not be described here. The battery control device 54 also has a function for determining whether the contact between the thermistor 23 and the planar area 21 is good or bad. Figure 15 shows the functional block, and the function is almost the same as that shown in Figure 6.

[0131] 15, a temperature adjustment member control unit 55 provided in a battery control device 54 controls the heating of a temperature adjustment member 50 via wiring 52, controlling the heating start time, heating time, heating end time, amount of heating energy, etc. The output voltage of the thermistor 23 generated by this heating is input via wiring 51 to a temperature measurement unit 56 provided in the battery control device 54 at predetermined time intervals and converted into temperature information. The temperature information can be obtained using an "output voltage-temperature table." This temperature information is stored in a RAM area (not shown) of the battery control device 54 at predetermined time intervals.

[0132] The battery control device 54 is equipped with a temperature change calculation unit 57, which calculates the degree of change (difference) in the temperature of the thermistor 23 over a predetermined time period, and this is input as an actual temperature change value (ΔTact) to a subsequent diagnostic unit 58. This actual temperature change value (ΔTact) can be obtained by reading out temperature information stored in a RAM area, and can be obtained by subtracting temperature information (T1) stored at a certain time from temperature information (T2) stored at a time a predetermined time after the time when the temperature information (T1) was obtained.

[0133] The battery control device 54 includes a memory unit 59 made up of a flash ROM or the like, which stores a temperature change threshold value (ΔTref), which is used as a reference value for determining whether good contact is maintained between the thermistor 23 and the flat area 21 of the battery container 13a. The temperature change threshold value (ΔTref) is input to a subsequent diagnostic unit 58. The temperature change threshold value (ΔTref) is as described in FIG. 7.

[0134] When the diagnosis unit 58 of the battery control device 54 determines whether good contact is maintained between the thermistor 23 and the flat area 21 of the battery container 13a, the result is sent to and stored in the memory unit 59. In this case, an error code is stored, and an operator can understand the diagnosis result by reading this error code with a dedicated inspection device.

[0135] 16 shows a control flow for determining whether good contact is maintained between the thermistor 23 in the battery control device 54 and the flat area 21 of the battery container 13a. Most of the control steps are the same as those in the control flow of FIG. 8, and therefore, a description of the same control steps will be omitted.

[0136] Step S10 to Step S16 The control flow is substantially the same as that shown in Fig. 8, and therefore description thereof will be omitted. However, the difference is that while the temperature adjustment member 28 is used in control step S10 of Fig. 8, the temperature adjustment member 50 is used in control step S10 of Fig. 16.

[0137] <Step S20> If it is determined in step S16 that good contact between the thermistor 23 and the flat area 21 of the battery container 13a is not maintained, an error code is stored in the memory unit 59 in step S20. The memory unit 59 is configured with a flash ROM, so the error code is not lost even if the power is shut down. Once the error code is stored, the process exits to END and ends.

[0138] When the worker analyzes the error code and finds that good contact is not maintained between the thermistor 23 and the flat surface area 21 of the battery container 13a, the worker corrects the attachment state of the thermistor 23 on the insulation cover 17 and redoes the assembly. Then, by newly executing the control flow (reproduction flow) in Fig. 16, it is possible to confirm that good contact is maintained between the thermistor 23 and the flat surface area 21 of the battery container 13a.

[0139] In this manner, in this embodiment as well, thermal energy can be directly applied to the battery container 13a by the temperature adjustment member 50, so a small amount of thermal energy is sufficient and power consumption can be kept low. Furthermore, since the thermistor 23 and the temperature adjustment member 50 are close to each other, heat is quickly transferred to the thermistor 23, making it possible to check the operation of the thermistor in a short time.

[0140] If thermistor 23 does not generate an output voltage even when heat is applied by temperature adjustment member 50, it can be detected that a failure or abnormality has occurred in thermistor 23. Furthermore, it can be detected whether good contact is being maintained between thermistor 23 and flat area 21 of battery container 13a based on the amount of temperature change within a predetermined time.

[0141] Furthermore, in this embodiment, the battery control device 54 determines whether good contact is maintained between the thermistor 23 and the flat area 21 of the battery container 13a, so the above-described diagnosis can be performed at any timing while the battery module 10 is in operation. For example, the control flow shown in Fig. 16 can be executed at the time of shipment or at predetermined intervals after installation in a vehicle.

[0142] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as defined in the claims. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0143] 10...battery module, 11...casing, 12...battery group, 13...unit battery, 13a...battery container, 13p...cell positive terminal, 13n...cell negative terminal, 14...cell holder, 15...end plate, 16...side plate, 17...insulation cover, 18...module cover, 21...flat area, 22...terminal storage section, 20...module cover, 23...thermistor, 24...storage recess, 25...spring means, 26...inspection through hole, 27...heat application area, 28...temperature control member, 29...laser irradiation member, 31...control device, 32...temperature control member control section, 33...temperature measurement section, 34...temperature change calculation section, 35...memory section, 36...diagnosis section, 37...output section.

Claims

1. a battery including a battery container containing a battery element; a temperature detector that is in contact with the outer surface of the battery container and thermally connected to the battery container; a covering member that covers a part of the battery container and has electrical insulation and rigidity to bring the temperature detector into contact with the battery container; The covering member has an inspection through-hole through which a heat applying means passes, and the temperature detector is disposed at a position outside a heat applying region when the inspection through-hole is orthogonally projected onto the outer surface of the battery container. A battery module characterized by:

2. The battery module according to claim 1, the temperature detector is disposed on the outer surface of the battery container on the side of the cell positive terminal and the cell negative terminal, The covering member is disposed so as to cover the temperature detector, and the temperature detector is disposed adjacent to the heat application region formed by the inspection through-hole. A battery module characterized by:

3. The battery module according to claim 2, The temperature detector is provided on the covering member at a position adjacent to the inspection through-hole formed in the covering member. A battery module characterized by:

4. The battery module according to claim 2, The heat applying means contacts the heat applying area and transfers heat or cold to the battery container. A battery module characterized by:

5. The battery module according to claim 4, The heat applying means is made of a resistance heating element and is in contact with the heat applying area to transfer heat to the battery container. A battery module characterized by:

6. The battery module according to claim 2, The heat applying means applies heat to the battery container without contacting the heat applying area. A battery module characterized by:

7. The battery module according to claim 6, The heat applying means is made of a laser irradiation member, and applies heat to the battery container by irradiating the heat applying region with laser light. A battery module characterized by:

8. The battery module according to any one of claims 2 to 7, The heat application area is provided with a heat application mark. A battery module characterized by:

9. The battery module according to any one of claims 2 to 7, A protective sheet is laid on the area of ​​the battery container on which the temperature detector, the cell positive electrode terminal, and the cell negative electrode terminal are located, except for the heat application area. A battery module characterized by:

10. The battery module according to any one of claims 2 to 7, A plurality of the batteries are stacked in one direction to form a battery group, The covering member extends in the one direction so as to cover the battery group, and has an opening at a predetermined position, and a signal lead wire of the temperature detector is led out from the opening, and the signal lead wire is arranged along the one direction of the covering member. A battery module characterized by:

11. The battery module according to claim 10, The covering member has two rows of the inspection through holes formed intermittently and continuously along the one direction at both ends in a direction perpendicular to the one direction, and the signal lead wire is arranged between the two rows of the inspection through holes. A battery module characterized by:

12. The battery module according to claim 11, The signal lead wire is connected to a socket fixed to the covering member. A battery module characterized by:

13. A method for inspecting a battery module, comprising: a heat application step of applying heat to the heat application region of the battery container of the battery module according to any one of claims 1 to 7 by the heat application means through the inspection through-hole; a temperature change value measuring step of determining a temperature change value from the temperature detector before and after a predetermined time has elapsed after the heat application step; After the temperature change value measurement step, the temperature change value is compared with a predetermined temperature change threshold value, and if the temperature change value is greater than the temperature change threshold value, it is determined that the contact state between the temperature detector and the battery container is normal, and if the temperature change value is smaller than the temperature change threshold value, it is determined that the contact state between the temperature detector and the battery container is normal. A diagnostic process to determine if the contact state of the pond container is abnormal. A battery module inspection method comprising:

14. The battery module inspection method according to claim 13, The temperature change threshold is a reference value for determining whether good contact is maintained between the temperature detector and the outer surface of the battery container. A battery module inspection method comprising:

15. A method for inspecting a battery module, comprising: a heat application step of applying heat to the heat application region of the battery container of the battery module according to any one of claims 1 to 7 by the heat application means through the inspection through-hole; a temperature change rate measuring step of determining a temperature change rate value from temperature change values ​​from the temperature detector before and after a predetermined time has elapsed after the heat application step; a diagnostic step of comparing the temperature change rate value with a predetermined temperature change rate threshold after the temperature change rate measurement step, and determining that the contact state between the temperature detector and the battery container is normal if the temperature change rate value is greater than the temperature change rate threshold, and determining that the contact state between the temperature detector and the battery container is abnormal if the temperature change rate value is less than the temperature change rate threshold; A battery module inspection method comprising:

16. The battery module inspection method according to claim 15, The temperature change rate threshold is a reference value for determining whether good contact is maintained between the temperature detector and the outer surface of the battery container. A battery module inspection method comprising:

17. The battery module inspection method according to claim 13 or 14, further comprising: The heat applying means used in the heat applying step is in contact with the heat applying region and transfers heat or cold to the battery container. A battery module inspection method comprising:

18. The battery module inspection method according to claim 17, The heat applying means is made of a resistance heating element and is in contact with the heat applying area to transfer heat to the battery container. A battery module inspection method comprising:

19. The battery module inspection method according to claim 13 or 14, further comprising: The heat applying means used in the heat applying step applies heat to the battery container without contacting the heat applying region. A battery module inspection method comprising:

20. 20. The battery module inspection method according to claim 19, The heat applying means is made of a laser irradiation member, and applies heat to the battery container by irradiating the heat applying region with laser light. A battery module inspection method comprising:

21. The battery module inspection method according to any one of claims 13 to 20, comprising: After the diagnosis step, an internal resistance diagnosis step is performed in which the internal resistance of the battery is measured to determine whether the battery is good or bad. A battery module inspection method comprising:

22. a battery including a battery container containing a battery element; a temperature detector that is in contact with the outer surface of the battery container and thermally connected to the battery container; a covering member that covers a part of the battery container and has electrical insulation and rigidity to bring the temperature detector into contact with the battery container; A heat applying means is provided on the outer surface of the battery container and is disposed adjacent to the temperature detector, and the heat applying means is controlled by a heat applying control device. The heat application control device includes: a heat applying function unit that applies heat to the temperature detector by the heat applying means; a temperature change value measuring function unit that obtains a temperature change value from the temperature detector before and after a predetermined time has elapsed after heat is applied by the heat application function unit; and and a diagnostic function unit that compares the temperature change value with a predetermined temperature change threshold, and determines that the contact state between the temperature detector and the battery container is normal if the temperature change value is greater than the temperature change threshold, and determines that the contact state between the temperature detector and the battery container is abnormal if the temperature change value is less than the temperature change threshold. A battery module characterized by:

23. The battery module according to claim 22, An outer covering member is provided on the outside of the covering member to cover the covering member, and the heat application control device is disposed between the covering member and the outer covering member. A battery module characterized by:

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