JP5097167B2 - Assembled battery - Google Patents

Description

  The present invention relates to a gas discharge device for an assembled battery, and more specifically, in an assembled battery in which a plurality of unit cells having a safety valve that releases gas when an internal pressure of a certain level or more is generated are arranged in parallel, the gas discharged from the safety valve is externally supplied. The present invention relates to an assembled battery provided with a gas discharge device that discharges to the surface.

  As a drive power source mounted on an electric vehicle, an assembled battery in which a plurality of unit cells are arranged in parallel, which is composed of a sealed rectangular battery and has a safety valve that releases gas when an internal pressure exceeding a certain level is generated, is preferably used. In such an assembled battery, when the internal pressure of the unit battery rises above a certain level due to the hydrogen gas generated during charging / discharging, the safety valve is activated and hydrogen gas is released. Therefore, for safety measures such as ignition prevention, It is necessary to discharge gas into the outside atmosphere, and a gas discharge device is provided.

  As a conventional gas discharge device for an assembled battery, for example, a device disclosed in Patent Document 1 is known. 14 and 15, the assembled battery 41 includes a plurality of (24 in the illustrated example) unit batteries 43 arranged in parallel in two rows (12 in the illustrated example), and unit batteries in each column. In the groups 42a and 42b, the gas discharge ports 44 of the unit cells 43 are alternately arranged in a staggered manner, and are alternately connected to two rows of exhaust gas lines 45a, 45b, 45c and 45d, and one end of each exhaust gas line is connected to the atmosphere. The discharge unit 46 is connected.

  T-joints 47 are provided at the gas discharge ports 44 of the unit cells 43, and exhaust gas lines 45 a to 45 d are configured by sequentially connecting between hose joints 48 projecting from both ends by exhaust gas tubes 49. Yes.

  In the case shown in FIG. 14, the exhaust gas lines 45a and 45d of the one unit battery group 42a and the other unit battery group 42b, and the other ends of 45b and 45c are connected by connection lines 50a and 50b, and the exhaust gas line 45a. Even if clogging occurs in any of .about.45d, it can be discharged from other connected exhaust gas lines.

JP 7-245089 A

  However, in the configuration of the conventional gas discharge apparatus as shown in FIGS. 14 and 15, the exhaust gas tubes 49 are sequentially connected to the hose joints 48 at both ends of the T-shaped joint 47 in the gas discharge port 44 to connect the exhaust gas lines 45 a to 45. 45d, the unit battery 43 is a sealed rectangular battery, and when the space between the gas discharge ports 44, 44 expands due to the increase in internal pressure, the exhaust gas tube 49 is pulled out from the hose joint 48. There is a problem that the sealing may be incomplete, or the exhaust gas lines 45a to 45d may be broken in some cases, causing hydrogen gas to leak.

  Further, it is necessary to connect the end portions of the exhaust gas tubes 49 to a large number of hose joints 48 in a state where a seal is ensured, which requires a great number of work steps at the time of assembly, resulting in a high cost. .

  In view of the above-described conventional problems, the present invention can ensure sealing performance even when a unit cell expands due to an increase in internal pressure, and can reduce the number of work steps during assembly and reduce costs. It aims at providing the assembled battery provided with.

The assembled battery of the first invention of the present invention is an assembled battery in which a plurality of unit cells each having a safety valve that discharges gas when an internal pressure of a certain level or more is generated are arranged in parallel. Each unit battery is disposed in one or a plurality of exhaust gas tubes that are disposed at one end side away from the longitudinal center line, are disposed along the unit cell arrangement direction, and are connected to an external exhaust unit. Connect the discharge port of the safety valve, and provide a cooling medium passage between the unit cells so that the cooling medium flows toward the exhaust gas tube. Each unit battery is sequentially arranged so that the safety valves are staggered in the unit cell arrangement direction. The exhaust ports are arranged in parallel in the opposite direction, and every other discharge port is arranged along the arrangement direction of the unit cells, and an expandable bellows portion is provided in a portion between the exhaust port connection portions of the exhaust gas tube. Cooling provided between batteries With a gas discharge device that has a smaller diameter in the horizontal direction at the part facing the medium passage than at the other parts, it is possible to minimize the deterioration of the cooling performance of the unit cell at the location where the exhaust gas tube is installed. .

Further, intervals, dimensions ranging increase in flow resistance due to the exhaust gas tube of the cooling fluid flowing from the cooling medium passage provided between the unit cells is less than 10% between the lower end of the unit of the upper surface and the exhaust gas tube of the battery In order to prevent the cooling performance of the unit battery from greatly deteriorating at that location even if an exhaust gas tube is installed, so that the cooling performance of the unit battery is not adversely affected. I can .

Further, in the assembled battery of the second invention, in accordance with the temperature gradient of the unit cells in the arrangement direction of the unit cells, the diameter dimension in the horizontal direction of the exhaust gas tube gradually decreases from the lower temperature to the higher one. A gas discharge device in which the horizontal diameter of the exhaust gas tube is changed is provided, and the cooling performance of each unit battery in the assembled battery can be made uniform throughout .

As is apparent from the above description, the assembled battery of the present invention is an assembled battery in which a plurality of unit batteries including a safety valve that discharges gas when an internal pressure exceeding a certain level is generated are arranged in parallel. Is arranged in each unit battery at a position distant from the longitudinal center line to one end side, arranged along the arrangement direction of the unit battery and connected to an external exhaust unit The discharge port of the safety valve of each unit battery is connected to the exhaust gas tube, and a cooling medium passage is provided between the unit cells so that the cooling medium flows toward the exhaust gas tube. The discharge ports are arranged in every other direction along the arrangement direction of the unit cells, and the bellows portions that can be expanded and contracted between the discharge port connection portions of the exhaust gas tubes. The exhaust gas chew The cooling capacity of the unit battery at the location where the exhaust gas tube is installed is equipped with a gas discharge device in which the horizontal dimension of the part facing the cooling medium passage provided between the unit batteries is smaller than the other part. Can be minimized.

Further, the distance between the upper surface of the unit battery and the lower end of the exhaust gas tube is set to a dimension in which the increase in the flow resistance by the exhaust gas tube of the cooling fluid flowing out from the cooling medium passage provided between the unit cells is less than 10%. If set, even if an exhaust gas tube is provided, the cooling performance of the unit battery can be prevented from greatly decreasing at that location, and the cooling performance of the unit battery can be prevented from being substantially affected .

  Also, according to the temperature gradient of the unit cells in the arrangement direction of the unit cells, the horizontal diameter of the exhaust gas tube is gradually reduced so that the horizontal diameter of the exhaust tube gradually decreases from the lower temperature to the higher temperature. Is changed, the cooling performance of each unit battery in the assembled battery can be made uniform throughout.

It is a perspective view which shows the whole schematic structure in one Embodiment of the assembled battery of this invention. It is a partial detailed longitudinal cross-sectional view in the same embodiment. It is a longitudinal cross-sectional view of the A section of FIG. The exhaust gas tube of the embodiment is shown, (a) is a front view, (b) is a bottom view, (c) is an enlarged cross-sectional view taken along the line BB in (b), and (d) is a C- in (b). It is C arrow expanded sectional view. The detail of the connection part of the discharge port of the exhaust gas tube and safety valve in the embodiment is shown, (a) is a longitudinal sectional view, (b) is a DD arrow sectional view of (a). It is a longitudinal cross-sectional view which shows the detail of the other structural example of the connection part of the discharge port of the exhaust gas tube and safety valve in the embodiment. It is a top view of the tube for external discharge | emission in the same embodiment. It is EE arrow sectional drawing of FIG. 7 which shows the attachment structure of the tube for external discharge | emission in the same embodiment. It is a graph which shows the change with the passage of time of the hydrogen permeability of an exhaust gas tube and the hydrogen concentration in a pack in the embodiment. The exhaust gas tube in other embodiment of the assembled battery of this invention is shown, (a) is a front view, (b) is a bottom view. It is explanatory drawing of the attachment state at the time of using the exhaust gas tube of FIG. It is a top view which shows the whole schematic structure in another embodiment of the assembled battery of this invention. It is a graph which shows the temperature distribution in the assembled battery in the same embodiment. It is a top view which shows the whole schematic structure of the gas discharge apparatus of the assembled battery of a prior art example. It is a perspective view of the principal part in the conventional example.

  Hereinafter, an embodiment in which the present invention is applied to an assembled battery used as a drive power source of an electric vehicle will be described with reference to FIGS.

  As shown in FIG. 1, the assembled battery 1 of the present embodiment has a plurality (38 in the illustrated example) of unit batteries 2 made of sealed nickel-hydrogen secondary batteries and arranged in parallel at both ends of the arrangement direction. End plates 3 are arranged, both end plates 3 are connected by a restraining band (not shown) to restrain the unit battery 2 group, and each unit battery 2 is connected in series by a bus bar module (not shown). It is configured.

  As shown in FIG. 2, each unit battery 2 shares a plurality of rectangular parallelepiped (six in this embodiment) battery case 4 having a narrow short side surface and a wide long side surface on the short side surface. Are integrated with each other to form an integrated battery case 5 and each battery case 4 accommodates a power generation element (not shown) to form a unit cell, and each unit cell is connected in series within the integrated battery case 5. Configured. Moreover, between each battery case 4 and 4 in the integrated battery case 5 is mutually connected, It is comprised so that the internal pressure of each battery case 4 may become the same.

  On the long side surface of the integrated battery case 5, the rib-like protrusions projecting at positions corresponding to both ends of each battery case 4 and extending in the vertical direction, and projecting in a matrix form at appropriate pitch intervals between the rib-like protrusions The passage forming protrusions 6 such as a large number of circular protrusions are provided, and the cooling medium passage 7 is formed between the unit cells 2 and 2 by bringing the tips of the passage forming protrusions 6 of the adjacent unit cells 2 into contact with each other. Is formed. Further, on the long side surface of the integral battery case 2, a protrusion 8 and a concave portion 9 that are fitted to each other when the long side surfaces of the unit battery 2 are overlapped and arranged in parallel to position the relative position in the longitudinal direction of the unit battery 2. Is provided.

  On the upper wall of the integrated battery case 5 of each unit battery 2, a safety valve 10 is disposed at an appropriate distance from the center line in the longitudinal direction to one end side, and the integrated battery case 5 is generated by hydrogen gas generated by charging and discharging. When the internal pressure exceeds a certain level, hydrogen gas is released. The safety valve 10 accommodates a valve body 12 made of a rubber-like elastic body in a valve case 11 having a valve opening 11a formed on the bottom surface, and the valve body 12 is compressed and closed at the top with a valve lid 13. At the same time, a cylindrical discharge port 14 is provided on the valve lid 13 so as to communicate with a through hole 13 a formed in the valve lid 13, and an umbrella-shaped protrusion 15 is provided on the outer periphery of the upper end of the discharge port 14. ing.

  As shown in FIG. 1, a gas discharge device 16 for discharging the hydrogen gas released from the safety valve 10 of each unit battery 2 at a time is disposed on the upper part of the assembled battery 1. In the assembled battery 1, the unit batteries 2 are connected in series, and the positive and negative connection terminals located at both ends are arranged in parallel in opposite directions so that they are alternately adjacent to each other. The discharge ports 14 are arranged in two rows along every other direction along the arrangement direction of the unit cells 2. Therefore, the gas discharge device 16 is an external discharge in which a pair of exhaust gas tubes 17 disposed over almost the entire length in the arrangement direction of the unit cells 2 and one end of the exhaust gas tube 17 protruding outside the end plate 3 are connected. And a drain hose 19 connected to one end of the external discharge tube 18. An intermediate portion of the external discharge tube 18 is supported by a support clip 20. Further, the discharge part 19 a at the tip of the drain hose 19 is opened at a lower position of the assembled battery 1.

  As shown in FIGS. 2 to 5, the exhaust gas tube 17 is provided with a discharge port connection portion 21 having a substantially rectangular shape in plan view and projecting downward from a position corresponding to the discharge port 14 of the safety valve 10. In addition, an expandable / contractible bellows portion 22 is formed between the discharge port connection portions 21 and 21 so as to absorb a change in the interval between the discharge ports 14 and 14 of the safety valve 10 due to the expansion of the unit battery 2. In FIG. 4, reference numeral 38 denotes a part around the exhaust gas tube 17 in order to prevent the cooling medium in the assembled battery 1 from flowing out from the through hole at one end of the exhaust gas tube 17 formed in the end plate 3. The seal rods are formed so as to cover the gap, and are provided at two positions with appropriate intervals so that they can be shared when the shape of the end plate 3 is different.

  A connection hole 23 is formed in the discharge port connection portion 21 perpendicularly to the axial direction of the exhaust gas tube 17, and the connection hole 23 is configured to be fitted to the discharge port 14 in a sealed state. On the inner periphery of the intermediate portion of the connection hole 23, a seal projection 24 is provided so as to ensure high sealing performance. Further, as shown in FIG. 5B, the length L of the fitting portion between the connection hole 23 and the discharge port 14 is set to be equal to or longer than the diameter D of the discharge port 14, and the exhaust gas tube 17 is external force. Even if it inclines, it is comprised so that a sealing state may be ensured. In addition, when the connection hole 23 and the discharge port 14 are fitted, the lower end step surface of the umbrella-shaped projecting portion 15 is engaged with the upper end surface of the connection hole 23 to prevent the discharge port connection portion 21 from coming off.

  The discharge port connection portion 21 has a high thickness by setting the thickness around the connection hole 23 to be larger than the thickness of the other portions of the exhaust gas tube 17. The rigidity of the rubber itself may be changed to increase the rigidity. Moreover, the press step part 21a which protrudes from the outer periphery of the exhaust gas tube 17 is provided in the both sides of the discharge port connection part 21, and as shown by the phantom line in FIG.5 (b), this press step part 21a is made into an exhaust gas tube. By pressing from above with a pressing tool F that straddles the upper portion of 17, the connection hole 23 is fitted into the discharge port 14, and the connection port 14 and the exhaust gas tube 17 can be connected. In addition, the length of the portion of the discharge port connection portion 21 that fits into the discharge port 14, that is, the length L of the connection hole 23 in the illustrated example, is shorter than the length N below the umbrella-shaped protrusion 15 of the discharge port 14. The clearance S is set so that a gap S is formed between the base end of the discharge port 14 of the safety valve 10 and the lower end of the discharge port connection portion 21. The connection hole 23 can be completely and surely fitted, and the completion of fitting can be confirmed by touch.

  Further, in the state where the exhaust gas tube 17 is connected to the discharge port 14 of each safety valve 10 as described above, the portion of the exhaust gas tube 17 facing the cooling medium passage 7 between the unit cells 2 and 2 as shown in FIG. Is configured such that the horizontal dimension between the discharge port connection portion 21 and the bellows portion 22 is the smallest, and adversely affects the flow of the cooling medium flowing through the cooling medium passage 7 as indicated by the arrow as much as possible. I try not to give it. Further, the distance H between the upper end surface of the integrated battery case 5 of the unit battery 2 and the lower end of the exhaust gas tube 17 is set such that the increase in the flow resistance of the cooling fluid flowing out from the cooling medium passage 7 by the exhaust gas tube 17 is less than 10%. The dimensions are set to a range. Further, in order to separate the lower end of the exhaust gas tube 17 from the upper surface of the unit cell 2 in this way, as shown in FIG. 5B, the exhaust gas tube 17 is formed in a tunnel shape with a flat lower end, and a cooling medium. The corners on both sides are rounded so as to minimize the flow resistance.

  Further, instead of forming the pressing step portions 21a on both sides of the discharge port connection portion 21, as shown in FIGS. 5 (a) and 5 (b), the exhaust gas tube 17 is connected to the upper surface of the discharge port connection portion 21. A shoulder 25 having high hardness may be provided so as to protrude from the upper end of the discharge port 14 so as to surround the hole 23. By doing so, the connection hole 23 of the discharge port connection portion 21 can be easily and reliably fitted to the discharge port 14 by pressing the upper portion of the exhaust gas tube 17. The shoulder portions 25 may protrude from both side portions of the connection hole 23 in the tube axis direction so that both ends thereof are connected to both side walls of the exhaust gas tube 17.

  2 to 5 show an example in which an umbrella-shaped protruding portion 15 is provided on the outer periphery of the upper end of the discharge port 14 as a connection structure between the discharge port 14 and the discharge port connection portion 21 of the safety valve 10. 6, an umbrella-shaped protruding portion 15 is provided on the outer periphery of the axial direction intermediate portion of the discharge port 14 of the safety valve 10, and the connection hole 23 of the discharge port connecting portion 21 has a larger upper portion than the umbrella-shaped protruding portion 15. An annular lip 26 that is in pressure contact with the outer periphery of the distal end portion of the discharge port 14 may be provided on the inner periphery of the upper portion.

  As shown in FIG. 7, the external discharge tube 18 is formed such that a connection port 27 for connecting a pair of exhaust gas tubes 17 near one end and the other end is bent in an L shape or branched in a T shape. Has been. Reference numeral 27a denotes a seal protrusion protruding from the outer periphery thereof. Further, a bellows portion 29 is provided between the connection ports 27 and 27 to adjust the variation in the interval between the fitting portion 28 of the support clip 20 that supports the external discharge tube 18 and the exhaust gas tubes 17 and 17.

  As shown in FIG. 8, the support clip 20 is clipped with respect to the end plate 3 that is a fixing member at one end of a belt-like plate 31 having spring properties and the cover member 30 of the assembled battery 1 that is bonded and fixed to the upper end thereof. A fitting portion 32 is formed to be fitted to the second end, and a holding portion 33 is formed at the other end so as to wrap the outer discharge tube 18 via the curved portion 34, so that the external discharge tube 18 is indicated by a virtual line. Further, it is supported on the end plate 3 side so that it can be displaced by a predetermined displacement amount d without difficulty.

  Moreover, in this embodiment, since the discharge part 19a of the drain hose 19 is arrange | positioned in the lower part of the assembled battery 1, the atmosphere in the closed space of the assembled battery 1 is forced in the state where hydrogen gas stagnated in the exhaust gas tube 17 If left unexhausted, the hydrogen gas in the exhaust gas tube 17 gradually permeates through the exhaust gas tube 17 to increase the hydrogen gas concentration in the closed space of the battery pack 1 and the explosion in which the hydrogen gas concentration in the closed space is 4% or more. There is a risk of reaching the limit.

  Considering the amount of hydrogen gas permeating through the exhaust gas tube 17, the surface area of the exhaust gas tube 17 is A, the thickness is L, the hydrogen permeation coefficient is α (× 10 −17 m 4 / N · S), the pressure difference is Δp, If the hydrogen permeation time is t, the hydrogen permeation amount W at time t is given by W = α · Δp · t · A / L. Since the hydrogen permeability coefficient α greatly depends on the temperature and material, the actual hydrogen gas concentration in the assembled battery 1 varies greatly depending on the operating temperature and the rubber material of the exhaust gas tube 17. Therefore, considering that the hydrogen permeation coefficient α of various rubbers at normal temperature is 20 to 40 and the hydrogen permeation coefficient α of rubber at 50 ° C. is 30 to 560, α = 20, 50, 100, 560 The relationship between the actual hydrogen concentration in the assembled battery 1 and the hydrogen permeation time t was calculated. The result is shown in FIG. From FIG. 9, when the hydrogen permeation coefficient α is 560 under the worst use conditions, the hydrogen gas concentration becomes 2%, which is obtained by dividing the explosion limit of 4% by the safety factor of 2 in 0.25 years. . Therefore, in the exhaust gas tube 17 of the present embodiment, the hydrogen gas concentration in the closed space that covers the assembled battery 1 with the hydrogen gas that has passed through the exhaust gas tube 17 may be 2% or more within 0.25 years. The diameter, thickness, and material of the exhaust gas tube are selected so that there is no problem.

  According to the gas discharge device 16 having the above configuration, when the integrated battery case 5 of the unit battery 2 expands due to an increase in internal pressure and the interval between the discharge ports 14 of the safety valve 10 increases, the bellows portion 22 of the exhaust gas tube 17 is The gas can be absorbed by the expansion, and there is no possibility that an unreasonable force acts on the connection portion between the exhaust gas tube 17 and the discharge port 14 and the seal therebetween becomes incomplete, and the leakage of hydrogen gas can be reliably prevented.

  Further, since the external discharge tube 18 connected to one end of both exhaust gas tubes 17 is attached to the support clip 20 so as to be displaceable in the arrangement direction of the unit cells 2, the unit cell 2 adjacent to the end plate 3 expands. Even when one end of the exhaust gas tube 17 moves in the direction of coming out of the end plate 3, the external discharge tube 18 follows and displaces as shown by the phantom line in FIG. There is no possibility that an excessive force acts on the connecting portion of the tube 18 and the sealing therebetween becomes incomplete, and hydrogen gas leakage can be reliably prevented. Further, since the support clip 20 is constituted by the belt-like plate 31 having spring properties, the above-described action can be obtained with a simple and inexpensive configuration.

  In addition, since a connection hole 23 in which the discharge port 14 of the safety valve 10 is fitted in a sealed state is formed in the discharge port connection portion 21 of the exhaust gas tube 17 perpendicularly to the longitudinal axis of the exhaust gas tube 17, By simply pressing the discharge port connection portion 21 toward the discharge port 14, the connection hole 23 is fitted into the discharge port 14, reducing the number of work steps during assembly and reducing the cost. Since the rigidity of the outlet connection portion 21 is made higher than that of other portions, the discharge port connection portion 21 is not carelessly deformed at the time of the connection, and the connection work is not difficult, and the connection workability is improved.

  Further, if a shoulder portion 25 having a high hardness that protrudes longer than the tip of the discharge port 14 of the safety valve 10 protrudes above the inner end of the tube at the discharge port connection portion 21 of the exhaust gas tube 17, the exhaust gas tube 17 is released at the time of connection. By pressing the upper part of the outlet connection part 21, it is possible to press the discharge port connection part 21 until it is completely fitted to the discharge port 14 without interfering with the upper end of the discharge port 14 at the shoulder 25, It can be connected easily and with good workability.

  Further, since the gap S is formed between the lower end of the discharge port connection portion 21 of the exhaust gas tube 17 and the base portion of the discharge port 14, the lower end of the discharge port connection portion 21 hits the base portion of the safety valve 10 and the discharge port. 14 is not completely fitted, and a complete connection state can be obtained with the connection hole 23 over the umbrella-shaped protrusion 15 and the connection is properly completed by the feeling when the connection hole 23 is over. I can confirm that.

  Moreover, since the umbrella-shaped protrusion 15 at the upper end of the discharge port 14 engages with the upper end surface of the discharge port connection portion 21 in the connected state, even when an upward external force is applied to the exhaust gas tube 17, it is prevented from accidentally coming out. it can.

  As shown in FIG. 6, an umbrella-shaped protrusion 15 is provided on the outer periphery of the intermediate portion in the axial direction of the discharge port 14 of the safety valve 10, and the distal end portion of the discharge port 14 is provided on the inner periphery of the tube inner end of the connection hole 23. By providing the annular lip 26 in pressure contact with the outer periphery, it is possible to prevent the exhaust gas tube 17 from unexpectedly coming out, and even when the safety valve 10 is activated and the gas is released, the pressure in that portion suddenly increases. Since the annular lip 26 exerts the sealing performance more strongly by the gas pressure, a high sealing performance can be secured even when the gas is released at a high pressure.

  In addition, the distance H between the upper surface of the unit battery 2 and the lower end of the exhaust gas tube 17 is increased by 10 due to an increase in the flow resistance by the exhaust gas tube 17 of the cooling fluid flowing out from the cooling medium passage 7 provided between the unit cells 2 and 2. Therefore, even if the exhaust gas tube 17 is provided, it is possible to prevent the cooling performance of the unit battery 2 from being greatly reduced at that location, and the cooling performance of the unit battery 2 is substantially reduced. Can be avoided. Further, the portion of the exhaust gas tube 17 facing the cooling medium passage 7 is not provided with the discharge port connection portion 21 and the bellows portion 22, and the portion with the smallest horizontal dimension is opposed to the exhaust gas tube 17. A decrease in the cooling performance of the unit battery at the location where the tube 17 is disposed can be minimized.

  In the above embodiment, the exhaust port connection portion 21 and the bellows portion 22 are provided in the exhaust gas tube 17 so that the cross-sectional shape greatly changes in the axial direction, and an example of manufacturing by injection molding is shown. Thus, when the exhaust gas tube 35 having the same cross section over the entire length is used, it can be manufactured at low cost by extrusion molding. The exhaust gas tube 35 is configured in a tunnel shape in which a flat portion having a large thickness is formed at the lower end, and connection holes 36 for fitting the discharge ports 14 of the safety valve 10 are formed at a predetermined pitch interval Q in the flat portion. . The pitch interval Q of the connection holes 36 of the exhaust gas tube 35 is set to be longer than the pitch interval P of the discharge ports 14 when the unit battery 2 is normally arranged. At the time of arrangement, as shown in FIG. Arranged in a bent state, the change in the interval of the discharge port 14 of the safety valve 10 due to the expansion of the unit battery 2 is absorbed by the extension of the exhaust gas tube 35.

  Moreover, in the said embodiment, although the cross-sectional dimension of the exhaust gas tube was equal along the arrangement direction of the unit battery 2 of the assembled battery 1, as shown in FIG. An exhaust gas tube 37 in which the diameter Dn (n = 1 to n) gradually changes may be provided. That is, the temperature of the unit batteries 2 (battery numbers M (M = 1 to n)) arranged in parallel in the assembled battery 1 gradually changes depending on the arrangement position depending on the arrangement state of the assembled battery 1 and the flow direction of the cooling medium. In accordance with the temperature gradient, the diameter of the horizontal direction of the exhaust gas tube 37 is gradually decreased from the lower temperature side to the higher temperature side, and the coolant flows through the exhaust gas tube 37 when the temperature is higher. The overall cooling performance is averaged by lowering the resistance to increase the cooling performance and lowering the cooling performance by relatively increasing the flow resistance of the cooling medium through the exhaust gas tube 37 at the lower temperature. .

  With this configuration, as shown in FIG. 13, in the case of the exhaust gas tube 17 in which the horizontal dimension is not changed, a temperature gradient is generated in the arrangement direction of the unit cells 2, whereas the horizontal diameter is In the case where the exhaust gas tube 37 with the dimensions changed is provided, the cooling performance of each unit battery 2 in the assembled battery 1 can be made uniform as a whole.

1 assembled battery 2 unit battery 7 cooling medium passage 10 safety valve 14 discharge port 15 umbrella-shaped protruding portion 16 gas discharge device 17 exhaust gas tube 18 external discharge tube 20 support clip 21 discharge port connection portion 22 bellows portion 23 connection hole 24 seal projection 25 Shoulder portion 26 Annular lip 31 Strip plate 32 Fitting portion 33 Holding portion 35 Exhaust gas tube 36 Connection hole 37 Exhaust gas tube

Claims (3)

An assembled battery in which a plurality of unit batteries having a safety valve that discharges gas when an internal pressure exceeding a certain level is generated are arranged in parallel,
The safety valve is disposed in each unit battery at a position away from the longitudinal center line to one end side,
The discharge port of the safety valve of each unit battery is connected to one or a plurality of exhaust gas tubes arranged along the arrangement direction of the unit cells and connected to the external exhaust section, and the cooling medium is connected to the exhaust gas tubes between the unit cells. A cooling medium passage is provided to flow toward the
The unit cells are sequentially arranged in opposite directions so that the safety valves are arranged in a staggered manner in the arrangement direction of the unit cells, and the discharge ports are arranged every other unit direction along the arrangement direction of the unit cells, An expandable bellows portion is provided between the exhaust port connection portions of the exhaust gas tube, and the horizontal dimension of the portion facing the cooling medium passage provided between the unit cells of the exhaust gas tube is smaller than the other portions. An assembled battery comprising a gas discharge device. A gas discharge device is provided in which the distance between the upper surface of the unit cell and the lower end of the exhaust gas tube is set to a size in which the increase in flow resistance by the exhaust gas tube of the cooling fluid flowing out from the cooling medium passage is less than 10%. The assembled battery according to claim 1 . An assembled battery in which a plurality of unit batteries having a safety valve that discharges gas when an internal pressure exceeding a certain level is generated are arranged in parallel,
The discharge port of the safety valve of each unit battery is connected to one or a plurality of exhaust gas tubes arranged along the arrangement direction of the unit cells and connected to the external exhaust section, and the cooling medium is connected to the exhaust gas tubes between the unit cells. A cooling medium passage is provided so as to flow in the direction of the unit cell, and the diameter dimension of the exhaust gas tube in the horizontal direction gradually decreases from the lower temperature to the higher temperature in accordance with the temperature gradient of the unit cells in the arrangement direction of the unit cells. An assembled battery comprising a gas discharge device in which the horizontal diameter of the exhaust gas tube is changed.

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