JP6119529B2 - Battery system - Google Patents

Description

  The present invention relates to a battery system capable of cooling a plurality of battery cells housed inside a case.

  Conventionally, for example, an apparatus described in Patent Document 1 is known as a battery pack having a function of cooling a battery.

  The device of Patent Literature 1 includes a plurality of single cells and a fan device for generating convection inside one case mounted on an automobile. The device of Patent Document 1 can cool a plurality of single cells housed in one case by forming convection so that air blown from a fan device contacts each single cell.

JP 2009-211829 A

  When there is a restriction on the space where the case described in Patent Document 1 can be installed, it may not be possible to install one case having the necessary power storage capacity. Therefore, a method is adopted in which a plurality of batteries in a case are distributed and arranged in a plurality of cases, and the occupied volume per case is reduced to constitute a battery system having a necessary storage capacity. Can do.

  When such a battery system is configured, for example, it is necessary to connect the cases with a duct in order to construct a flow path for cooling fluid for cooling the batteries in all cases. According to this configuration, there is a problem that a duct to be connected to each case and a duct connecting process are required, and that a space for installing the duct is required, so that the installation is easily restricted. Further, in all cases, it is necessary not only to provide a cooling fluid flow path as described above, but also to suppress external noise.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a battery system that realizes suppression of product cost, ensuring of battery cooling capacity, suppression of noise, and securing of mountability.

In order to achieve the above object, the present invention employs the following technical means. That is, one of the inventions related to the disclosed battery system includes a plurality of batteries (3) connected to be energized by conductors, and a plurality of battery packs (1) for accommodating a plurality of batteries dispersedly in each battery pack. The connection between each of the battery packs so as to connect a battery stored in one battery pack and a battery stored in the other battery pack among the plurality of battery packs so as to be energized. A plurality of inter-pack connecting conductors (90) which are conductors and connect all of the plurality of batteries accommodated in the plurality of battery packs so as to be energized; and a communication member interposed between the predetermined battery packs, a plurality of packs communication member sent connected predetermined battery information about the contained battery pack (93) is provided inside the pack case (2) forming each battery pack, the A fluid drive means (4) for circulating a fluid for cooling the battery in the pond pack inside of the battery pack, a circulation passage of the fluid formed in the enclosed space inside the pack case, the outflow from the fluid drive means A circulation path (5) forming a series of circulation paths sucked into the fluid drive means after the heat exchanged with the battery is carried out, and the battery provided inside the pack case are distributed and accommodated, and the sealed space A plurality of battery cases (60) lined up in
The circulation passage is a passage formed inside each of the plurality of battery cases, and the battery passage (52) that flows when the fluid that has flowed out from the fluid driving means exchanges heat with the battery, and after the battery passage has flowed out. A collecting passage (53) formed in a duct connecting all the battery passages and the suction portion (54) of the fluid driving means so that fluids gather and flow in the same direction toward the fluid driving means; Including
Each of the battery cases has an inlet portion of a battery passage that opens toward a sealed space through which fluid flows out of the fluid driving means, and an outlet portion of the battery passage connected to the collecting passage,
All of the fluid flowing out to the enclosed space from the fluid drive means, is distributed to the battery passage in each of the plurality of battery case, after flowing down the respective cell passage, the Rukoto is sucked into the suction unit is collected in manifolds Features.

  According to the present invention, since each battery pack has a cooling function for the battery to be accommodated, a cooling duct extending between the battery packs is unnecessary, and a duct and a connection process thereof are not required. Therefore, since the number of parts of the battery system can be reduced, the manufacturing cost can be suppressed, and the system mountability can be improved.

  Further, the fluid driving means built in the battery pack circulates the fluid inside the battery pack. According to this configuration, since the battery cooling fluid is circulated inside the pack, there is no propagation of sound to the outside due to the discharge of the fluid. Therefore, it is possible to suppress the noise generated from the inside of the pack such as the fluid driving means from propagating to the outside of the pack. Further, since the wall of the pack case forming the battery pack can be used as a heat dissipation medium, the heat inside the pack case can be urged to be released to the outside of the pack case. Thereby, it is possible to construct an efficient heat dissipation path for effectively discharging the heat generated by the battery to the outside of the pack case. Also, dust is less likely to enter the pack and condensation is less likely to occur. Furthermore, since the fluid inside the pack can be sufficiently stirred by the circulating flow formed inside the pack, it is possible to contribute to enhancing the endothermic effect on the battery.

  Further, according to the battery system, the plurality of battery packs are coupled by the plurality of inter-pack connection conductors and the plurality of inter-pack communication members. Thereby, the some battery which has an output required for a battery system can be disperse | distributed and installed in several packs. For this reason, since the physique per battery pack can be reduced in size, it is possible to mount packs that effectively utilize spaces of various sizes and shapes, and it is possible to realize mounting of a battery system having a high degree of freedom. As described above, according to the present invention, it is possible to provide a battery system that realizes suppression of product cost, ensuring of battery cooling capability, suppression of noise, and securing of mountability.

  In addition, the code | symbol in parentheses described in a claim and each said means is an example which shows the correspondence with the specific means as described in embodiment mentioned later easily, and limits the content of invention is not.

It is a schematic diagram for demonstrating the fluid flow in each pack case about the battery system of 1st Embodiment. It is a schematic diagram for demonstrating the relationship between a some battery pack, a high voltage line, and a communication line about the battery system of 1st Embodiment. It is the figure which looked at the inside of a vehicle from the side, Comprising: It is the schematic diagram which showed the vehicle mounting location of the battery pack which concerns on 1st Embodiment. It is the figure which looked at the inside of a vehicle from the top, Comprising: It is the schematic diagram which showed the vehicle mounting location of the battery pack which concerns on 1st Embodiment. It is a figure for demonstrating the vehicle mounting location of the battery pack which concerns on 2nd Embodiment, Comprising: It is the schematic diagram which looked at the vehicle inside from the top. It is a figure for demonstrating the vehicle mounting location of the battery pack of 2nd Embodiment, Comprising: It is the general | schematic perspective view which showed a part of trunk room. It is a schematic diagram for demonstrating the relationship between a some battery pack, a high voltage line, and a communication line about the battery system of 3rd Embodiment. It is a schematic diagram for demonstrating the relationship between the inside of a junction box and a high voltage line about the battery system of 3rd Embodiment.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly indicate that the combination is possible in each embodiment, but also the embodiments are partially combined even if they are not clearly specified unless there is a problem with the combination. It is also possible.

(First embodiment)
The battery system of the first embodiment will be described with reference to FIGS. FIG. 1 is a schematic diagram for explaining the configuration of each battery pack 1 included in the battery system 100 and the fluid flow in the pack case 2. FIG. 2 is a schematic diagram for explaining the relationship between the plurality of battery packs 1 included in the battery system 100, the high voltage line 90, and the communication line 93. FIGS. 3 and 4 are diagrams for explaining a vehicle mounting location of the battery pack included in the battery system 100.

  The battery system 100 is used in, for example, a hybrid vehicle that uses an internal combustion engine and a motor driven by electric power charged in the battery as a travel drive source, an electric vehicle that uses a motor as a travel drive source, and the like. The plurality of battery cells 3 included in the battery system 100 are, for example, a nickel hydrogen secondary battery, a lithium ion secondary battery, or an organic radical battery.

  The battery system 100 includes a plurality of battery packs 1, a high voltage line 90 that connects the battery packs 1 to be connected so as to be energized, and a communication line 93 that connects the battery packs 1 to be connected so as to be communicable. At least. The high voltage line 90 can energize a predetermined battery cell 3 accommodated in one battery pack 1 and a battery cell 3 accommodated in another one of the plurality of battery packs 1. The connection conductors are interposed between the battery packs so as to be connected.

  A predetermined number of high voltage lines 90 provided in the battery system 100 charge all the battery cells 3 included in the battery system 100 and carry power for discharging to an external device such as a motor. These high voltage lines 90 are a plurality of inter-pack connecting conductors that connect all of the plurality of battery cells 3 accommodated in the plurality of battery packs 1 so that energization is possible. The plurality of high voltage lines 90 connect the battery cells 3 included in each battery pack 1 in series or in parallel. Further, output terminals 91 and 92 for external devices are connected to the ends of the high voltage line 90 located at both ends of the battery system 100, respectively.

  Communication line 93 is a communication member interposed between predetermined battery packs in battery system 100. A predetermined number of communication lines 93 provided in the battery system 100 can transmit predetermined battery information regarding all the battery cells 3 included in the battery system 100 to the system control device 8 or the like outside the battery pack 1. It is a communication member. The plurality of communication lines 93 are connected to the battery cells 3 included in each battery pack 1 and output battery information for each battery pack to the system control device 8 or the like by a battery signal. For example, the communication line 93 includes a voltage detection line and a temperature detection line, and outputs a battery temperature and a battery voltage at a predetermined part in each battery pack 1 to the system control device 8 and the like.

  The battery pack 1 includes a plurality of battery cells 3, a pack case 2 that forms a sealed space, and a fluid drive unit that circulates fluid in the pack case 2. Inside the pack case 2 are housed a plurality of battery cells 3 and a blower 4 which is an example of a fluid driving means.

  The pack case 2 is a housing in which a plurality of battery cells 3 and a blower 4 are accommodated. The pack case 2 accommodates a plurality of battery cells 3 that are electrically connected in series so as to be energized and stacked. Inside the pack case 2, a circulation passage 5 is formed that forms a circulation path of a fluid that is forced to flow by the blower 4. The circulation passage 5 is a passage formed inside the pack case 2 and through which the fluid circulates. The circulation passage 5 forms a flow path for a series of fluids sucked into the blower 4 after the fluid blown by the blower 4 exchanges heat with the battery cells 3. As shown in FIG. 1, the circulation passage 5 constitutes a series of distribution paths connecting the inflow passage 54, the blowout passage 50, the top wall side passage 51, the battery passage 52 and the collecting passage 53.

  The plurality of battery cells 3 are controlled by electronic components (not shown) used for charging and discharging or temperature control. The electronic components are, for example, a DC / DC converter, a motor that drives the blower 4, electronic components controlled by an inverter, various electronic control devices, and the like. The electronic component may be housed in the pack case 2 or may be installed outside. Further, the electronic component can be cooled together with the battery cell 3 by circulation of fluid by being installed in the circulation passage 5 inside the pack case 2.

  The battery system 100 includes a system controller 8 including a battery monitoring unit that monitors at least the voltage and temperature of the battery cell 3 outside the pack case 2. The system control device 8 is configured to be able to communicate with all the battery packs 1 included in the battery system 100, and can receive information from each battery pack 1. The battery monitoring unit calculates a function as a monitoring means for monitoring a battery state such as temperature, voltage, current, etc. for the battery cells 3 included in each battery pack 1, and calculates a change in voltage, a variation in voltage, and a movement amount of electric charge. It has a function as a calculating means.

  The system control device 8 or the battery monitoring unit includes an input circuit, a microcomputer, and an output circuit, like the vehicle ECU. In the storage means of the microcomputer, the battery state is stored as data as needed. The stored battery information data includes, for example, battery voltage, charge / discharge current, battery temperature, and the like in the battery system 100.

  The battery monitoring unit detects a battery voltage between predetermined portions in each battery pack 1 based on a signal input via a voltage detection line. The battery monitoring unit detects the battery temperature of a predetermined part in each battery pack 1 based on a signal input via the temperature detection line. The battery monitoring unit calculates and records information such as SOC (State of Charge) associated with changes in the discharge current of the battery system 100 using the input and stored data, and stores the battery temperature, single cell voltage, and total battery voltage. And various information such as battery voltage variations are transmitted to the vehicle ECU.

  The pack case 2 has a box shape composed of a plurality of wall surfaces surrounding an internal space, and is formed of a molded product of an aluminum plate or an iron plate. The pack case 2 is a pack case having at least six surfaces, for example. The pack case 2 can be manufactured by forming a box-like space inside by joining and assembling a plurality of case bodies. Moreover, you may make it form a convex part or a recessed part in a predetermined wall surface among the several wall surfaces of the pack case 2 in order to enlarge a thermal radiation area.

  The battery cells 3 included in each battery pack 1 constitute a plurality of cell stacks in the internal space of the pack case 2. As shown in FIG. 1, the cell stack is installed at a predetermined interval in the internal space of the pack case 2, and is accommodated in the battery case 60 so as to be surrounded by the battery case 60. In each battery case 60, the top wall 20 side of the pack case 2 opens toward the internal space of the pack case 2, and the bottom wall 22 side of the pack case 2 is connected to the collecting duct 61. Thereby, each passage such as the battery passage 52 in the battery case 60 in which each cell stack is installed is provided with an independent fluid inlet on the top wall 20 side, and is a part of the circulation passage 5. An outlet portion for fluid that collects in one collecting passage 53 on the wall 22 side is provided.

  The collective duct 61 includes a downstream end 31 of each battery cell 3, a suction portion (for example, an inflow passage 54) of the casing 42, a bottom wall 22, and a plurality of side walls 23, 24 adjacent to the bottom wall 22. It is a connecting duct. The collecting duct 61 forms a collecting passage 53 through which the air flowing out from each battery passage 52 can come into contact with the bottom wall 22 and the plurality of side walls 23, 24. Therefore, the collecting passage 53 of the battery pack 1 is a passage formed by at least the downstream end 31 of each battery cell 3, the bottom wall 22, the plurality of side walls 23, 24, and the like.

  The collecting passage 53 extends along the bottom wall 22 from below all the cell stacks arranged at a predetermined interval to the suction port of the casing 42 and is connected to the inflow passage 54. The collecting passage 53 included in the circulation passage 5 is a passage in which the fluid after heat exchange with the plurality of battery cells 3 gathers and flows in the same direction toward the fluid driving means. Therefore, the heat released from the fluid flowing through the collecting passage 53 is transmitted to the case wall such as the bottom wall 22 and is discharged to the outside of the pack case 2 through the bottom wall 22 and the like.

  Further, the fluid that has reached the top wall side passage 51 by the blower 4 flows into each battery passage 52 from the inlet portion at the top of the battery case 60. The battery passage 52 may be an inter-cell passage formed between adjacent battery cells 3. The top wall side passage 51 is a passage formed between the top wall 20 and the plurality of battery cells 3. The fluid flowing through the circulation passage 5 absorbs heat from the outer surface of each battery cell 3 and cools each battery cell 3 when flowing through the battery passage 52. The fluid that has cooled each battery cell 3 is collected in the collecting passage 53 from the outlet at the bottom of the battery case 60 and is sucked into the blower 4 through the inflow passage 54. In this case, one of the heat dissipating means of the battery cell 3 is the exterior pack case surface of the cell.

  Further, when the fluid circulates in the pack case 2, the electrode contacts the electrode terminal 30 of the battery cell 3 including the positive electrode terminal and the negative electrode terminal and the bus bar that electrically connects the different electrode terminals. 30 and the bus bar can also constitute one of the heat dissipation means. In the battery case 60, the electrode terminal 30 and the bus bar are located on the upper side and the upstream side of the fluid flow. Therefore, the fluid that has flowed out of the blower 4 flows around the electrode terminal 30 and the bus bar and then flows into the collecting passage 53.

  The blower 4 is an example of a fluid driving unit that circulates a fluid that cools the plurality of battery cells 3 accommodated in the pack case 2 through a circulation passage 5 that is configured in the pack case 2. As the fluid for cooling the battery, for example, air, various gases, water, and a refrigerant can be used. Here, the blower 4 is fluid driving means for forcibly circulating air through the circulation passage 5. The blower 4 includes a motor 41, a sirocco fan 40 that is rotated by the motor 41, and a casing 42 that houses the sirocco fan 40. The casing 42 forms an inflow passage 54 that is a part of the circulation passage 5.

  The blower 4 is controlled by, for example, a system control device 8 including a battery monitoring unit. The battery cell 3 self-heats at the time of output from which current is taken out and at the time of input to be charged. The system control device 8 constantly monitors the temperature of the battery cell 3 in each battery pack 1 and controls the operation of the blower 4 based on the temperature of the battery cell 3.

  The inflow passage 54 includes a suction port of the casing 42 and extends in the rotation axis direction of the sirocco fan 40, and air sucked by the sirocco fan 40 passes therethrough. As shown in FIG. 1, the sirocco fan 40 is installed at a lower portion of the internal space of the pack case 2 and close to the side wall 21 of the pack case 2. The motor 41 is installed between the side wall 21 and the sirocco fan 40. The rotation axis of the sirocco fan 40 is installed in a posture that is parallel to the top wall 20 and the bottom wall 22 of the pack case 2. The inflow passage 54 is a passage located on the battery cell 3 side and is connected to the collecting passage 53. That is, the suction port of the casing 42 is connected to the collective duct 61.

  Further, the casing 42 forms an outlet passage 50 that is a part of the circulation passage 5. The blowout passage 50 is a passage extending in the centrifugal direction of the fan perpendicular to the rotation axis of the sirocco fan 40. The outlet passage 50 is a passage extending in a direction orthogonal to the inflow passage 54. Therefore, the outlet passage 50 extends upward in the internal space of the pack case 2. The blow-out part of the casing 42 is connected to a blower duct 43 extending upward. The air duct 43 opens at a site near the top wall 20 of the pack case 2. With this configuration, the outlet passage 50 communicates with a portion near the top wall 20 in the internal space of the pack case 2.

  The circulation passage 5 is not exposed to the wall surface of the pack case 2 in the passage formed by the air duct 43, the battery case 60, and the casing 42, and is not exposed to the wall surface of the pack case 2 in the top wall side passage 51 and the collective passage 53. An exposed passage is formed. Therefore, the circulating flow contacts the wall surface of the pack case 2 when flowing through the top wall side passage 51 and the collecting passage 53. The circulation passage 5 includes a passage portion in which a circulation flow circulating in the pack case 2 by the operation of the blower 4 flows while contacting at least one wall surface among the plurality of wall surfaces forming the pack case 2.

  Wall surfaces in contact with air in the process of air circulation are the top wall 20 and the bottom wall 22, and passage portions through which air flows while in contact with the top wall 20 and the bottom wall 22 are the top wall side passage 51 and the collecting passage 53. . When the circulating air flows through the collecting passage 53, the heat absorbed immediately after exchanging heat with the battery cell 3 is radiated to the outside of the pack case 2 through the bottom wall 22. In addition, the circulating air radiates heat to the outside of the pack case 2 through the top wall 20 immediately before heat exchange with the battery cell 3 when flowing through the top wall side passage 51. The heat released through the top wall 20 is radiated to the outside of the pack case 2 by natural convection. Therefore, the entire top wall 20 and the entire bottom wall 22 function as a heat radiating surface when the heat of the battery cells 3 accommodated in the pack case 2 is released to the outside.

  The bottom wall 22 and the top wall 20 are preferably wall surfaces having the largest surface area among the plurality of wall surfaces forming the pack case 2. This is because when the bottom wall 22 and the top wall 20 that are heat radiating surfaces are the wall surfaces having the largest surface area in the wall surface of the pack case 2, the heat radiating effect to the outside can be increased and the battery can be effectively cooled. For example, when the pack case 2 is a rectangular parallelepiped, the bottom wall 22 and the top wall 20 are wall surfaces having the largest surface area.

  The pressure valve 62 forms an open passage that communicates the internal space of the pack case 2 with the outside. When the internal pressure of the pack case 2 is increased for some reason, the open passage is a passage through which the air overflowing from the circulation passage 5 is discharged to the outside by the operation of the pressure valve 62. The open passage is a passage that opens to other wall surfaces except the top wall 20 that contacts when the circulating air flows through the top wall side passage 51. For example, as shown in FIG. 1, the open passage is provided so as to penetrate a portion of the bottom wall 22 that does not form a part of the collecting passage 53. In other words, the open passage is provided at a position where air inside the pack case 2 leaking from the circulation passage 5 flows out. For example, the open passage passes through the bottom wall 22 and communicates the inside and the outside of the pack case 2 at a position facing the casing 42 that is out of the circulation passage 5 and the collecting passage 53.

  The open passage is formed by a small-diameter hole penetrating the pack case 2, and an annular portion that is thinner than other portions is formed around the hole. This small-diameter hole is set to a size such that air is not discharged outside through the open passage when external air is not taken into the pack case 2 and the internal air of the pack case 2 continues to circulate through the circulation passage 5. ing. Therefore, the internal space of the pack case 2 forms a sealed space except for the open passage.

  As shown in FIGS. 3 and 4, the battery pack 1 included in the battery system 100 can be installed below the front seat 73 and below the rear seat 74 provided in the vehicle interior 70 of the vehicle 7. The battery pack 1 is installed below the front seat 73 and the rear seat 74 with the bottom wall 22 and the collecting passage 53 facing downward. Further, each battery pack 1 has a feature that it is not necessary to provide a duct for cooling the battery, and is therefore a pack suitable for installing the pack case 2 below the seat.

  The plurality of battery packs 1 mounted on the vehicle 7 are communicably connected as a single battery system 100 through a high voltage line 90 and a communication line 93. Therefore, the plurality of battery cells 3 included in the battery system 100 can be distributed and installed in the plurality of pack cases 2 in the vehicle 7. According to the battery system 100, a system having a required output can be configured even in an environment where the installation space of the battery is severely restricted.

  The pack case 2 of the battery pack 1 is mounted on the vehicle 7 so as to contact a floor surface 75 provided on the vehicle 7. The heat in the pack case 2 is transmitted to the floor surface 75 through the case wall. The bottom wall 22 which is a part of the pack case 2 is preferably in contact with the floor surface 75. Inside the pack case 2 is provided a collecting passage 53 that flows into contact with the bottom wall 22 after the circulating flow contacts the battery cells 3 in the pack case 2 and exchanges heat with the battery cells 3. Therefore, the heat in the pack case 2 is transmitted to the floor surface 75 through the bottom wall 22 from the fluid flowing through the collecting passage 53 after heat exchange with the battery cells 3.

  Further, the space where the battery pack 1 below the rear seat 74 is installed may communicate with the trunk room back space 72 below the trunk room 71. The installation space can also be configured to communicate with the outside of the vehicle. Moreover, you may make it interpose the thermal radiation sheet excellent in thermal conductivity in the contact part of the bottom wall 22 and the floor surface 75. FIG. The heat in the pack case 2 is transmitted from the bottom wall 22 to the floor surface 75 through the heat dissipation sheet.

  Moreover, the battery cell 3 accommodated in each battery pack 1 which comprises the battery system 100 is set so that the output voltage may be 48 volts or less. That is, the number of battery cells 3 accommodated in each battery pack 1 and the output value per cell are set so that the output voltage per battery pack is 48 volts or less. Thereby, the number of the battery packs 1 is determined so that a required output value can be secured for the battery system 100 as a whole. Further, the number of battery packs 1 included in the battery system 100 and the output voltage value of each battery pack 1 are determined so that a necessary output value can be secured for the battery system 100 as a whole.

  Next, the effect which the battery system 100 brings is demonstrated. The battery system 100 includes a plurality of battery packs 1 in which a plurality of battery cells 3 are distributed and accommodated in each battery pack 1, a plurality of inter-pack connection conductors, a plurality of inter-pack communication members, and each battery pack 1. Fluid driving means. Each inter-pack connecting conductor can energize a predetermined battery cell 3 accommodated in one battery pack 1 and a battery cell 3 accommodated in another one of the battery packs 1. It is interposed between predetermined battery packs so as to be connected to each other. Each inter-pack communication member is interposed between predetermined battery packs, and is connected to be able to transmit predetermined battery information related to the battery cells 3 in the battery pack 1 to the system control device 8. The fluid driving means is provided in each battery pack 1 and circulates a fluid for cooling the battery cells 3 accommodated in the battery pack 1 inside the pack case 2.

  According to this battery system 100, since each battery pack 1 has the cooling function of a battery cell, the cooling duct over between the battery packs 1 is unnecessary. That is, there is no need for parts costs related to the duct, parts management, etc., and no duct connecting process is required. Therefore, since the number of parts of the battery system 100 can be reduced, the manufacturing cost can be suppressed and the degree of freedom for mounting the system can be improved.

  Further, the fluid driving means built in the battery pack 1 circulates the fluid inside the battery pack 1. According to this configuration, since the battery cooling fluid is circulated inside the pack, there is no propagation of sound to the outside due to the discharge of the fluid. Therefore, it is possible to suppress the noise generated from the inside of the pack such as the fluid driving means from propagating to the outside of the pack. Further, since the wall of the pack case 2 forming the battery pack 1 can be used as a heat dissipation medium, the heat inside the pack case 2 can be urged to be radiated to the outside of the pack case 2. As a result, an efficient heat radiation path for effectively discharging the heat generated by the battery to the outside of the pack case 2 can be constructed. Also, dust is less likely to enter the pack and condensation is less likely to occur. Furthermore, since the fluid inside the pack can be sufficiently stirred by the circulating flow formed inside the pack, it is possible to contribute to enhancing the endothermic effect on the battery cells 3.

  Moreover, according to the battery system 100, the some battery pack 1 is connected with the some inter-pack connection conductor and the some inter-pack communication member. Thereby, the some battery cell 3 which has an output required for the battery system 100 can be disperse | distributed and installed in several packs. For this reason, since the physique per battery pack can be reduced in size, it is possible to mount packs that effectively utilize spaces of various sizes and shapes, and the mounting of the battery system 100 with a high degree of freedom can be realized. . As described above, the battery system 100 achieves product cost reduction, battery cooling capability, noise suppression, and mountability.

  The pack case 2 forms a sealed space. According to this configuration, the pack case 2 does not have a fluid inlet and outlet, and the fluid is discharged compared to the conventional method in which a large amount of cooling air is taken in from the outside and the battery is cooled and then exhausted. Along with this, no sound propagates to the outside. Therefore, it is possible to suppress the noise generated from the blower 4 and the like from propagating to the outside of the pack case 2. In addition, dust does not easily enter the pack case 2 and condensation does not easily occur. Further, since the cooling fluid circulates in the circulation passage 5 provided in the sealed space, it is also possible to secure a circulation flow rate of air for sufficiently absorbing the heat of the battery cells 3. Moreover, since the inside of the pack case 2 can be sufficiently stirred by the circulating flow formed in the sealed space, the endothermic effect on the battery cells 3 can be enhanced.

  Moreover, the battery cell 3 accommodated in each battery pack 1 is set so that the output voltage is 48 volts or less. According to this configuration, the voltage of each battery pack 1 can be suppressed to a safe level even in a situation where the inter-pack connecting conductor (for example, the high voltage line 90) that connects the battery packs in a conductive manner is disconnected. In addition, even if an electrical leakage occurs, the output voltage is suppressed, so that it is not necessary to provide a relay device for each battery pack 1, and it is possible to contribute to the reduction in the number of system components and the cost of components.

  The pack case 2 is mounted on the vehicle 7 so as to come into contact with a floor surface 75 provided on the vehicle 7. According to this, since the pack case 2 is directly attached to the floor surface 75 of the vehicle 7, the heat of the battery cells 3 is radiated from the case wall to the outside via the floor surface 75, and heat loss is suppressed. A heat transfer path can be constructed. Further, each battery pack 1 is a pack suitable for directly attaching the pack case 2 to the floor surface 75 because it is not necessary to provide a duct for cooling the battery.

  Further, the bottom wall 22 which is a part of the pack case 2 is in contact with the floor surface 75. Inside the pack case 2, a passage (for example, a collecting passage 53) that flows down while contacting the bottom wall 22 after the fluid contacts the battery cell 3 in the pack case 2 and exchanges heat with the battery cell 3 is provided. ing. According to this configuration, the fluid immediately after cooling the battery cell 3 can be brought into contact with the bottom wall 22, can be thermally transferred to the bottom wall 22, and can be radiated to the outside via the floor surface 75. Therefore, an efficient heat transfer path that can dissipate heat to the outside of the case after the heat absorption from the battery cell 3 can be provided.

  Further, the circulation passage 5 provided in the pack case 2 is surrounded by a plurality of wall surfaces forming the pack case 2. In this way, since the plurality of wall surfaces of the pack case 2 surrounding the circulation passage 5 can be used as a heat dissipation medium, the heat dissipation area to the outside can be increased, and heat dissipation to the outside of the pack case 2 can be promoted. Thereby, it is possible to construct a heat path that effectively exhausts heat generated by the battery cells 3 to the outside of the pack case 2. That is, it is possible to realize effective battery cooling by utilizing the wall surface of the pack case 2 widely as a heat radiation area.

  The circulation passage 5 is a passage portion (for example, a ceiling) in which a circulating fluid flows while contacting at least one wall surface (for example, the top wall 20 and the bottom wall 22) of the plurality of wall surfaces forming the pack case 2. The wall side passage 51 and the collecting passage 53) are included. According to this configuration, when the circulating fluid flows through the top wall side passage 51 and the collecting passage 53, heat can be radiated to the outside of the pack case 2 through the top wall 20 and the bottom wall 22. Thus, since at least one wall surface of the pack case 2 can be used as a heat radiating medium, a heat radiating area to the outside can be secured, and heat generated by the battery cell 3 can be effectively exhausted to the outside of the pack case 2. A route can be constructed.

  The collecting passage 53 is a passage formed by at least the downstream end portion 31 of the battery cell 3, the bottom wall 22, and a plurality of side walls 23 and 24 adjacent to the bottom wall 22. According to this configuration, when the circulating fluid flows through the collecting passage 53, heat can be radiated to the outside of the pack case 2 through the bottom wall 22, the plurality of side walls 23, 24, and the like. Thus, since at least one wall surface of the pack case 2 can be used as a heat radiating medium, a heat radiating area to the outside can be secured, and heat generated by the battery cell 3 can be effectively exhausted to the outside of the pack case 2. A route can be constructed. Moreover, according to this structure, the flow which gathers the fluid after heat-absorbing from the battery cell 3 reliably can be formed, and also the smooth flow which flows down in the same direction toward a fluid drive means can be formed.

  In addition, the fluid after passing through each battery passage 52 is sucked into the fluid driving means, so that the flow rate passing through the periphery of each battery cell 3 can be made uniform.

  Moreover, it is preferable that the bottom wall 22 comprises the wall surface which has the largest surface area among the several wall surfaces which form the pack case 2. FIG. According to this configuration, for the fluid after battery cooling, since the wall surface constituting the heat radiating surface is the wall surface having the largest surface area in the wall surface of the pack case 2, the heat radiating effect to the outside can be increased, and the battery cooling effect can be increased. Can be bigger.

  Further, the pressure valve 62 includes a passage that is opened when a pressure equal to or higher than a predetermined value is applied, so that air is discharged to the outside of the pack case 2 when a predetermined pressure condition is satisfied. Thereby, unnecessary discharge | emission of air can be prevented and there exists a noise suppression effect.

  In addition, the battery pack 1 is installed with the bottom wall 22 facing downward, so that the internal pressure of the pack case 2 is released when the internal pressure of the pack case 2 increases and the pressure valve 62 operates. It can be discharged smoothly from the passage. That is, since a large space can be secured below the bottom wall 22 where the pressure valve 62 is provided, the air resistance at the time of air discharge can be significantly reduced.

  Further, the plurality of battery cells 3 are provided side by side in a direction along at least the top wall 20 of the pack case 2. The fluid that has flowed out of the fluid driving means flows along the top wall 20 and further flows downward to exchange heat with each battery cell 3.

  Further, the fluid flowing out from the fluid driving means is brought into contact with the top wall 20 and further flows down toward the plurality of battery cells 3 arranged along the top wall 20, thereby suppressing variation in the flow rate flowing to each battery cell 3, Uniformity can be achieved. Further, according to this configuration, the heat of the fluid flowing out from the fluid driving means can be released to the outside of the pack case 2 through the top wall 20 before the fluid and the battery cell 3 exchange heat. In this way, it is possible to construct a heat path for exhausting the heat of the battery cells 3 that could not be released to the outside before being sucked into the fluid drive means to the outside of the pack case 2 before exchanging heat with the battery cells 3. .

  The plurality of battery cells 3 are provided with the electrode terminal 30 facing up. The fluid that has flowed out of the fluid drive means flows around the electrode terminal 30 and then flows into the collecting passage 53. According to this structure, after cooling the electrode terminal 30 in which the heat generation of each battery cell 3 tends to collect, the exterior pack case of the battery cell 3 can be cooled. Therefore, efficient battery cooling can be implemented.

(Second Embodiment)
2nd Embodiment demonstrates the other form which concerns on the installation place of the battery pack 1 contained in the battery system 100 with reference to FIG.5 and FIG.6. In each figure, the same components as those in the first embodiment are denoted by the same reference numerals and have the same operations and effects. The configuration, operation, and effects not particularly described in the second embodiment are the same as those in the first embodiment. Only differences from the first embodiment will be described below. Moreover, what has the structure similar to 1st Embodiment in 2nd Embodiment shall show | play the same effect | action and effect demonstrated in 1st Embodiment.

  The battery system according to the second embodiment includes a battery pack 1 installed in a rear wheel installation width area located at both ends of the vehicle width in the trunk room 71. The rear wheel installation width area is an area where a cover portion 712 is provided so as to cover the outer peripheral surface of the rear wheel above the rear wheel. In other words, the rear wheel installation width area is a volume area that occupies the range of the length of the cover portion 712 in the vehicle width direction and occupies the range of the vertical length of the trunk room 71 in the upward direction. The rear wheel installation width area is set at both ends of the trunk room 71 in the vehicle width direction. And if the battery pack 1 is a rear-wheel installation width area, you may install it anywhere. For example, the battery pack 1 may be installed above the cover part 712, or may be installed on the rear side or the front side with respect to the cover part 712.

  The cover part 712 has a shape protruding from the floor surface 75 of the trunk room 71. For this reason, the luggage space 710 where the luggage can be loaded is substantially a volume region inside the rear wheel installation width area at both ends in the trunk room 71. Therefore, since the rear wheel installation width area is not assumed as a load space for luggage, it is also a dead space. Therefore, when the battery pack 1 of the battery system 100 is installed in the rear wheel installation width area, it does not protrude into the luggage space 710 that is assumed in advance. For example, the golf bag is placed horizontally with its longitudinal direction as the vehicle width direction. However, there is no problem with the load capacity.

  The battery pack 1 can store spare tires, tools, and the like, and may be installed in a trunk room lower area 711 provided below the trunk room 71.

  According to the second embodiment, the battery pack 1 is located at both ends of the trunk room 71 in the vehicle width direction and is installed in the rear wheel installation width area 713 including the rear and upper sides of the cover part 712. According to this, it is possible to provide a battery system 100 that can fully utilize the feature that each battery pack 1 has a small volume and can effectively use the space of the trunk room 71 without eroding the luggage space.

(Third embodiment)
In the third embodiment, another form of connection between the inter-pack connection conductors (for example, the high voltage line 90) will be described with reference to FIGS. In each figure, the same components as those in the first embodiment are denoted by the same reference numerals and have the same operations and effects. The configuration, operation, and effects not particularly described in the third embodiment are the same as those in the first embodiment. Only differences from the first embodiment will be described below. Moreover, what has the structure similar to 1st Embodiment in 3rd Embodiment shall show | play the same effect | action and effect demonstrated in 1st Embodiment.

  The battery system 200 includes a junction box 94 for connecting and connecting the inter-pack connecting conductors. Junction box 94 connects current connection devices of battery cells 3 included in the plurality of battery packs 1 and accommodates a current control device that controls current. The current control device is, for example, a relay device or a resistance device.

  The junction box 94 accommodates a connecting terminal portion 941 to which the inter-pack connecting conductor is relay-connected in the middle thereof, and a relay device 942. The relay device 942 is provided in the middle of the inter-pack connecting conductor, and switches on and off the current by switching between the energized state and the non-energized state.

  For example, when some inter-pack connecting conductors are damaged due to some cause including a vehicle collision, a potential difference corresponding to a battery cell in an electrically connected state is applied to the damaged conductor portions. In this situation, this potential difference may conduct through some electrical medium to the part that may be touched by a person. Therefore, according to the battery system 200 of the third embodiment, since the junction box 94 that relay-connects the inter-pack connecting conductors by the connecting terminal portion 941 or the like is provided, the potential difference between the battery cells in the electrically connected state is reduced. It is possible to keep it at a safe level.

  For example, if the inter-pack connecting conductors for connecting the battery packs are connected by the connecting terminal portion 941, only a potential difference corresponding to one battery pack is generated at the damaged portion. In addition, a relay device 942 is installed in the middle of the inter-pack connecting conductor that connects the battery packs. When the system control device 8 detects an impact of a predetermined value or more, the relay device 942 is opened and the non-energized state is switched. Like that. Thereby, the battery packs connected by the relay device 942 can be in a non-conductive state.

(Other embodiments)
In the above-described embodiment, the preferred embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. It is. The structure of the said embodiment is an illustration to the last, Comprising: The scope of the present invention is not limited to the range of these description. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  In the above embodiment, the system control device 8 has a battery monitoring unit and detects predetermined battery information in all the battery packs 1, but is not limited to this form. Each battery pack 1 or a predetermined number of battery packs may be configured to include a battery monitoring unit, and the system control device 8 may be configured to acquire each battery information from each battery monitoring unit. .

  The battery pack 1 according to the above embodiment may not include the pressure valve 62, may not allow fluid to enter and exit from the interior of the pack case 2, and may have the internal space of the pack case 2 as a sealed space.

  As the blower 4 provided inside the pack case 2, an sirocco fan, an axial fan, a turbo fan, or the like can be used.

  Further, in the pack case 2, the wall surface having the largest surface area is not limited to the top surface and the bottom surface of each pack case, and may be a side surface or another surface.

DESCRIPTION OF SYMBOLS 1 ... Battery pack 2 ... Pack case 3 ... Battery cell (battery)
4 ... Blower (fluid drive means)
75 ... Floor surface 90 ... High voltage wire (inter-pack connecting conductor)
94. Communication line (communication member between packs)

Claims (6)

A plurality of batteries (3) connected to be energized by a conductor;
A plurality of battery packs for housing distributed to each of the battery pack a plurality of said battery (1),
Among the plurality of battery pack, predetermined, between the battery pack to connect the energizable and the battery accommodated in the battery and other one of said battery pack accommodated in one of said battery pack each a connection conductor that is interposed, and a plurality of packs between connecting conductors which connect all of the plurality of batteries accommodated in the plurality of the battery packs to be energized (90),
A plurality of inter-pack communication members (93) connected between the predetermined battery packs so as to be able to transmit predetermined battery information relating to the batteries contained in the battery pack;
Wherein provided within the pack case (2) forming each battery pack, the fluid drive means (4) for circulating a fluid for cooling the battery in the battery pack inside the battery pack,
A circulation path of the fluid formed in a sealed space inside the pack case, and a series of flow paths in which the fluid flowing out from the fluid driving means is sucked into the fluid driving means after exchanging heat with the battery A circulation passage (5),
A plurality of battery cases (60) arranged in the sealed space, in which the batteries provided in the pack case are distributed and accommodated;
Equipped with a,
The circulation passage is a passage formed inside each of the plurality of battery cases, and a battery passage (52) through which the fluid flowing out of the fluid driving means exchanges heat with the battery, and the battery Formed in the duct connecting all the battery passages and the suction portions (54) of the fluid drive means so that the fluids after flowing out of the passages gather and flow in the same direction toward the fluid drive means. An assembled passage (53),
Each of the battery cases has an inlet portion of the battery passage that opens toward the sealed space where the fluid flows out of the fluid driving means, and an outlet portion of the battery passage connected to the collecting passage. And
All of the fluid flowing out from the fluid driving means into the sealed space is distributed to the battery passages in each of the plurality of battery cases, and after flowing down each of the battery passages, the fluid is collected in the collecting passage and collected. cell system to be sucked into the suction unit, wherein Rukoto. Before Kipa Kkukesu The battery system according to claim 1, characterized in that it mounted on the vehicle to contact the floor surface provided on the vehicle (75). The merge passage is cell system according to claim 2, wherein the fluid is a passage for flowing down while contacting the bottom wall (22) which is part of the pack case.   The battery pack is located at both ends in the vehicle width direction in the trunk room (71) of the vehicle, and is installed in a rear wheel installation width area (713) including the rear and upper sides of the cover part (712) covering the upper part of the rear wheel. The battery system according to any one of claims 1 to 3, wherein:   5. The battery system according to claim 1, wherein the battery housed in each battery pack is set so that an output voltage is 48 volts or less. 6.   Accommodates a connecting terminal portion (941) where the inter-pack connecting conductor is relay-connected in the middle, and a relay device (942) which is provided in the middle of the inter-pack connecting conductor and switches between an energized state and a non-energized state. The battery system according to any one of claims 1 to 5, further comprising a junction box (94).

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