JP6724846B2 - Heat dissipation device for battery pack and bus bar - Google Patents

Description

The disclosure in this specification relates to a heat dissipation device for a battery pack and a bus bar.

Patent Document 1 discloses a battery pack in which a switching element for performing current control on a battery is mounted on a control board. According to paragraph 0021 of Patent Document 1, the mounting portion of the switching element on the control board faces the element heat radiation portion of the base mounted on the vehicle, and the heat generated by the switching element is the element heat radiation portion and the base bottom plate portion. Is released to the vehicle through. According to FIG. 6 and paragraph 0058 of Patent Document 1, a bus bar is connected to the control board. The bus bar electrically connects the terminal block, which is thermally connected to the base, to the control board. The contents of the prior art documents listed as the prior art are incorporated by reference as explanations of the technical elements in this specification.

JP, 2014-13722, A

In the battery pack of Patent Document 1, the bus bar generates a large amount of heat because current flows. The heat of the bus bar is transmitted to the base through the terminal block and the second route to the control board through the connecting portion between the bus bar and the control board, and further to the bottom plate of the base through the element heat dissipation section. Is released to. In the second path, the heat of the bus bar passes through the control board, so the temperature difference between the control board to which the heat of the switching element is transmitted and the bus bar itself does not become so large. The larger the temperature difference, the more the heat moves to the lower temperature side. Therefore, in the conventional technology, the amount of heat transferred from the bus bar to the control board is small, and the heat dissipation of the bus bar is required to be improved. In addition, in the battery pack, when increasing the heat dissipation of the bus bar, it is also required to suppress the size increase from the viewpoint of the mounting space.

An object of the disclosure in this specification is to provide a battery pack and a heat dissipation device for a bus bar, which can improve heat dissipation of the bus bar and effectively use space.

The aspects disclosed in this specification employ different technical means to achieve their respective purposes. The claims and the reference numerals in parentheses in this section are examples showing the correspondence with specific means described in the embodiments described later as one aspect, and limit the technical scope. is not.

One of the disclosed battery packs is a battery (20), a battery housed in a housing (11, 30), and a part of the housing having a heat dissipation wall (31) and a vehicle-side member ( 19) a base (30) having a mounting part (32) installed so as to be heat-transferable, and electric parts (54, 55) provided so as to be heat-transferable with respect to a heat dissipation wall and through which current flows, A bus bar (21, 22 ) that is provided so as to be able to transfer heat to the heat dissipation wall and that is electrically connected to the electric component;
The bus bar protrudes to the outside of the current path of the bus bar so as not to extend outside the outer peripheral edge of the housing, and is extended by heat transfer with respect to the base (1 21b1, 122d1). ) have a,
The current path is a path connecting the upstream end and the downstream end of the current in the bus bar,
The extension portion is a portion that branches from the middle of the rectangular plate-shaped main body provided in the middle of the current path and projects outward from the main body,
Heat of the bus bar that are provided by a heat dissipation path to move to the base via an extension.

According to this battery pack, the extension part formed so as to be separated from the current path in the bus bar is installed so as to be able to conduct heat to the base which is a part of the housing. According to this configuration, since the heat radiation path for moving the heat generated by the bus bar to the base without passing through the electric component is provided, the heat radiation amount from the bus bar can be increased. According to this heat dissipation path, heat is dissipated to the base where a temperature difference from the bus bar can be secured, so that the amount of heat transferred from the bus bar to the base can be increased. Since the extension portion is installed in a range that does not extend outside the outer peripheral edge of the housing including the mounting portion, the base, etc., the extension portion is installed in the dead space, which is a space that does not particularly function in the battery pack. be able to. Therefore, it is possible to provide a battery pack capable of improving the heat dissipation of the bus bar and effectively utilizing the space.

The disclosed heat dissipation device for a bus bar is a part of the housing (11, 30), has a heat dissipation wall (31), and is attached to an external member (19) so that heat can be transferred to an attachment part (32). ) Having a base), an electric component (54, 55) through which heat can be transferred to the heat dissipation wall, and a current flows, and a heat transferable relative to the heat dissipation wall. And a bus bar (21, 22 ) connected to each other so that electricity can be supplied,
The bus bar protrudes to the outside of the current path of the bus bar so as not to extend outside the outer peripheral edge of the housing, and is extended by heat transfer with respect to the base (1 21b1, 122d1). ) have a,
The current path is a path connecting the upstream end and the downstream end of the current in the bus bar,
The extension portion is a portion that branches from the middle of the rectangular plate-shaped main body provided in the middle of the current path and projects outward from the main body,
Heat of the bus bar that are provided by a heat dissipation path to move to the base via an extension.

According to this heat dissipation device for the bus bar, the extension portion formed so as to be separated from the current path in the bus bar is installed so as to be able to conduct heat to the base that is a part of the housing. According to this configuration, since the heat radiation path for moving the heat generated by the bus bar to the base without passing through the electric component is provided, the heat radiation amount from the bus bar can be increased. According to this heat dissipation path, heat is dissipated to the base where a temperature difference from the bus bar can be secured, so that the amount of heat transferred from the bus bar to the base can be increased. Therefore, it is possible to provide a heat dissipation device for a bus bar that can improve the heat dissipation of the bus bar and effectively use the space.

It is a top view which shows the battery pack of 1st Embodiment. It is a top view which shows the state which removed the cover about a battery pack. It is a top view showing a switch device, a bus bar, and a terminal block. It is the arrow line view which looked at FIG. 3 in the IV direction. It is a perspective view showing a bus bar combined with a switch device. It is the arrow line view which looked at FIG. 3 in the VI direction. FIG. 6 is a partial cross-sectional view showing a coupling relationship between a base, a bus bar and a terminal block. It is a fragmentary sectional view showing the connecting state of the electrode terminal and the bus bar of a switch device. It is a figure which shows the heat transfer path|route from a switch apparatus and a bus bar in the battery pack of 1st Embodiment. It is a partial view showing composition which insulates a bus bar. It is a figure which shows the heat transfer path|route from a switch apparatus and a bus bar in the battery pack of 2nd Embodiment.

Hereinafter, a plurality of modes for carrying out the present disclosure will be described with reference to the drawings. In each form, parts corresponding to the items described in the preceding form may be designated by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each mode, the other mode described above can be applied to the other part of the configuration. Not only the combination of parts that clearly states that each form can be specifically combined, but also if there is no problem in the combination, it is possible to partially combine the forms even if not explicitly stated. It is possible.

(First embodiment)
The battery pack 1 of the first embodiment will be described with reference to FIGS. 1 to 10. In each drawing, a vertical direction or a height direction H1, a width direction W1, and a depth direction D1 are illustrated. In the battery pack 1 of this embodiment, the height direction H1 is set to the vertical direction as one of installation examples. The width direction W1 and the depth direction D1 are also the horizontal direction orthogonal to the height direction H1.

The battery pack 1 can be applied to a vehicle equipped with a plurality of cells. An example of a vehicle is a vehicle. The battery pack 1 is mounted, for example, under the seat of a vehicle. The battery pack 1 is arranged in a space between a front seat and a floor of a vehicle, between a rear seat and a floor, a space between a rear seat and a trunk room, a space between a driver's seat and a passenger seat, and the like. The vehicle is, for example, a hybrid vehicle that uses the battery pack 1 as a traveling drive source by combining an internal combustion engine and a battery-driven motor, an electric vehicle that is driven by a battery-driven motor, and the like. In this embodiment, an example in which the battery pack 1 is mounted on a hybrid vehicle will be described. The battery pack 1 in this embodiment is installed, for example, such that the width direction W1 is the width direction of the vehicle.

As shown in FIG. 1, the battery pack 1 includes a cover 11 and a base 30. In the battery pack 1, a part of a housing having at least the cover 11 and the base 30 is fixed to a vehicle-side member 19 which is an external member. The cover 11 and the base 30 form an outer shell of the battery pack 1 and constitute a housing of the battery pack 1. The cover 11 and the base 30 are a pack case that houses each functional component. The cover 11 is made of resin. The cover 11 constitutes an outer shell of the upper part or the ceiling of the battery pack 1. The base 30 constitutes an outer shell of the lower portion or the bottom portion of the battery pack 1.

FIG. 2 shows the battery pack 1 with the cover 11 removed. The battery pack 1 cooperates with a vehicle generator motor (MG) 15. The battery pack 1 provides a vehicle electric system. The generator motor 15 is connected to an internal combustion engine (EG) 16. The battery pack 1 is connected to an electric load (LD1) 17 and an electric load (LD2) 18 in the vehicle. The electric load 17 is an electric load such as an external battery or a starter through which a large current flows. The electric load 18 is a general electric load that is a protected load, and is, for example, a wiper such as an audio device, a navigation device, a headlight, a front windshield, a blower fan for an air conditioner, a defroster heater for a rear windshield, or the like. is there.

The generator motor 15 functions as a generator by being driven by the internal combustion engine 16. The battery pack 1 is charged by supplying at least a part of the electric power generated by the generator motor 15 to the battery pack 1. When the generator motor 15 is supplied with electric power from the battery pack 1, the generator motor 15 functions as an electric motor. The generator motor 15 functions as a power source together with the internal combustion engine 16. For example, the generator motor 15 supplies power that exceeds the power supplied by the internal combustion engine 16 or power that supplements the power supplied by the internal combustion engine 16. The generator motor 15 is, for example, a motor that assists the engine when restarting the engine from idling stop or during acceleration.

The battery pack 1 includes a terminal block unit 14 that inputs and outputs electric power. The terminal block unit 14 includes a terminal block unit 14A for connecting a Pb storage battery, a terminal block unit 14B for connecting an ISG, and a terminal block unit 14C for connecting a protected load. The terminal block unit 14A has a first input/output terminal 41 connected to the external battery side and a terminal block that supports the first input/output terminal 41. The terminal block unit 14B has a second input/output terminal 42 connected to the rotating machine side and a terminal block that supports the second input/output terminal 42. Each terminal block is made of a material such as resin having electrical insulation and thermal conductivity. The terminal block unit 14A and the terminal block unit 14B have their respective terminal blocks fixed to the base 30 at positions that are arranged side by side in the direction D1. Therefore, each of the terminal block units 14A, 14B, 14C is installed in a state where heat can be transferred to and from the base 30.

An external battery is connected to the first input/output terminal 41 of the terminal block unit 14A via a harness. The first input/output terminal 41 is electrically connected to an electric component, a unit cell or the like by a conductive bus bar 21. The rotating machine is connected to the second input/output terminal 42 of the terminal block unit 14B via a harness. The second input/output terminal 42 is electrically connected to an electric component, a unit cell, etc. by the conductive bus bar 22. The rotating machine is, for example, a motor generator. For example, a vehicle ECU is connected to the third input/output terminal 43 of the terminal block unit 14C, and the third input/output terminal 43 is configured to be connectable to the above-described electric load that is a target of power supply from the battery pack 1. .. The third input/output terminal 43 is electrically connected to an electric component, a unit cell, or the like by a conductive bus bar 24.

The bus bar 24 includes an extension portion 24b1 that extends outward by a predetermined length with respect to the electrical connection portion 24b that is in contact with the third input/output terminal 43 in the bus bar 24. The extension portion 24b1 is a part of the bus bar 24 that extends on the opposite side of the main portion of the bus bar 24 that connects the substrate 51 or the electrical component and the third input/output terminal 43 with respect to the electrical connection portion 24b. The extension portion 24b1 may be a portion that extends outward beyond the electrical connection portion 24b so as to extend the main body portion of the bus bar 24, or further extends outward from the electrical connection portion 24b in a direction intersecting the main body portion. It may be an extended portion. With this configuration, the current flowing from the main body of the bus bar 24 toward the third input/output terminal 43 forms a path toward the electric load 18 via the electrical connection portion 24b and the third input/output terminal 43. To do.

That is, the extension portion 24b1 is a portion formed of a conductive material, but is a portion deviated from the current path. The extension portion 24b1 is a portion protruding outside the current path in the bus bar 24 so as to be separated from the current path. The current path is a path connecting the upstream part and the downstream part in which current flows in the bus bar 24. The extension portion 24b1 is a portion protruding from the upstream end portion or the downstream end portion of the current path of the bus bar 24 to the outside of the current path. The extension portion 24b1 is installed so that heat can be transferred to the base 30.

The extension portion 24b1 is located in a portion where a current does not easily flow, and has a very small amount of current as compared with the main body portion and the electrical connection portion 24b, so that the heat generated by the current is very small. Due to this action, the temperature of the extension portion 24b1 becomes lower than that of other energized portions of the bus bar 24, so that the heat of the bus bar 24 is easily transferred to the extension portion 24b1 and is radiated to the outside from the extension portion 24b1. The extension 24b1 is thermally connected to the base 30 via the terminal block unit 14C. Therefore, the heat released from the extension 24b1 to the outside moves to the base 30 via the terminal block unit 14C and is further released to the vehicle-side member 19 via the stay 32. The extension portion 24b1 is installed so as to be capable of heat transfer with respect to the base 30 at a position separated from a heat dissipation wall 31 on which an electric component such as a switch device is provided so as to be heat transferable.

The outer peripheral edge of the extension portion 24b1 is surrounded by the side wall forming the terminal block unit 14C. Since this side wall is formed of an insulating material, it contributes to secure an insulation distance from the extension 24b1. The extension portion 24b1 is provided so as not to protrude outside the outer ends of the plurality of stays 32 in the base 30. The extension portion 24b1 is provided so as not to project outside the outer end of the stay 32a located closest to the plurality of stays 32.

The extension portion 24b1 is provided such that the outer end of the extension portion 24b1 is located on the outer frame AR1 illustrated by a chain double-dashed line in FIGS. 1 and 2, or the entire extension portion 24b1 is included inside the outer frame AR1. Has been. The area on the outer frame AR1 and the area inside the outer frame AR1 is an area that does not extend outside the outer end of the attachment portion of the battery pack 1 to the vehicle-side member 19. Therefore, locating the extension 24b1 in this area means installing the extension 24b1 in the dead space of the battery pack 1. As described above, the extension portion 24b1 is a portion that protrudes to the outside of the current path in the bus bar 24 so as to be out of the current path in the bus bar 24 in a range that does not extend outside the outer peripheral edge of the housing of the battery pack 1. The extension 24b1 is installed where the functional parts such as the fixing part and the energizing part of the battery pack 1 do not exist, and the extending part 24b1 does not extend beyond the outermost part of the battery pack 1. The extension portion 24b1 is provided in the dead space of the battery pack 1 in such a place. In addition, "it does not protrude" is meant to include a case where the tip of the extension portion 24b1 exists on the line of the outer frame AR1.

The extension 24b1 is preferably configured such that the cross-sectional area of the extension 24b1 is equal to or larger than the cross-sectional area of the portion of the current path of the bus bar 24 where the current density is maximum. The current density is a value of current flowing per unit cross section. The part where the current density is maximum is, for example, a main part where a large current flows in the bus bar 24. The main body part is a part where the currents flowing through the plurality of current paths merge. In addition, it is preferable that the surface area of the extension portion 24b1 be equal to or larger than the surface area of the portion of the current path of the bus bar 24 where the current density is maximum. In addition, the extension portion 24b1 is preferably a portion where the cross-sectional area or surface area of the bus bar 24 is maximum.

Each terminal block unit is provided on the outer peripheral portion of the pack case and is exposed to the outside of the battery pack 1. The terminal block unit 14A, the terminal block unit 14B, and the terminal block unit 14C are integrated with the pack case, and are arranged side by side in the lateral direction at a position closer to the switch device 54 than the switch device 55. The terminal block unit 14A, the terminal block unit 14B, and the terminal block unit 14C are installed integrally with the pack case on the outer peripheral portion of the pack case between the stays 32a and 32b of the stays 32 that are a plurality of mounting portions. ing. Further, the terminal block unit 14A, the terminal block unit 14B and the terminal block unit 14C may be provided as a part of the pack case, or by being a component separate from the pack case and attached to the pack case, It may be configured to be installed integrally with the pack case.

Next, the configuration of the bus bars 21, 22, 23 and the relationship between the bus bars 21, 22, 23, the switch devices 54, 55, and the input/output terminals 41, 42 will be described with reference to FIGS. The switch devices 54 and 55 are semiconductor switches widely known as transistors, MOSFETs, IGBTs, and the like. Further, the switch devices 54 and 55 may be mechanical relays that open and close the contacts using electromagnetic force. Unlike the switch device 53, the switch devices 54 and 55 are an example of electric components that control a large current, and correspond to heating elements. In addition to the switch devices 54 and 55, a resistor may be included in the electric component as a heating element having a heat transfer path capable of radiating heat to the base 30 via the bus bar like the switch devices 54 and 55.

The switch devices 54 and 55 are configured to be connected to the substrate 51 in a signal communicable state by signal line portions 541 and 551 through which current for power supply does not flow. Furthermore, the switch devices 54 and 55 are configured such that the power line portions 542 and 552 through which a large current for power supply flows are not connected to the substrate 51. In each of the switch devices 54 and 55, a large current flowing through the device body and the power line portions 542 and 552 is not transmitted to the substrate 51.

The switch devices 54 and 55 have a flat outer shape in which the width dimension of the main body is longer than the thickness dimension. The switch devices 54 and 55 are installed at a position where the main body is away from the substrate 51 and in a horizontal orientation such that the thickness direction thereof is orthogonal to the surface that is the main surface of the substrate 51. The switch devices 54 and 55 indirectly contact the heat dissipation wall 31 via a sheet-shaped member 90 having heat conductivity. The heat dissipation wall 31 is provided on the base 30 in a form that allows heat transfer to the stay 32 of the base 30. In the switch devices 54 and 55, the direction in which the signal line portions 541 and 551 and the power line portions 542 and 552 project from the main body is the direction along the main surface of the substrate 51. The switch devices 54 and 55 are installed so that the direction of the element width forming the length between the end portions where the signal line portions 541 and 551 and the power line portions 542 and 552 project is along the main surface of the substrate 51. ing.

The signal line portions 541 and 551 are connected to the board 51 by projecting in the lateral direction from the main body and then bending so as to be bent in a direction orthogonal to the main surface of the board 51, or are mounted on the board 51. It is connected to the. The power line portions 542 and 552 are conductive component side terminals that are not connected to the substrate 51 and are connected to the first input/output terminal 41 and the second input/output terminal 42 via the bus bars 21, 22, and 23. is there.

The power line portions 542 and 552 are conductive component-side terminals that are joined to the bus bars 21, 22, and 23 by welding or the like. The bus bar 21, the bus bar 22, and the bus bar 23 are copper conductive members supported by a bus bar support member 25 housed in the base 30 together with the assembled battery and the like. The bus bar support member 25 is also a bus bar housing case that houses the bus bar 21, the bus bar 22, and the bus bar 23 in a stable state. The bus bar support member 25 is made of an electrically insulating material and insulates each bus bar from surrounding members.

The means for fixing the main bodies of the switch devices 54, 55 to the sheet-shaped member 90 or the heat dissipation wall 31 can be configured by an adhesive having an insulating property, for example, a silicon adhesive, or fastening and fixing with bolts or screws. The heat transferred from the main bodies of the switch devices 54, 55 to the heat dissipation wall 31 through the member 90 moves to the side wall of the base 30 and the like, and then further moves to the vehicle-side member 19 via the stay 32 by the heat dissipation path of the battery pack 1. It is released to the outside.

Each bus bar is a conductive plate-shaped member, is connected to the power line portion 542 and the power line portion 552 of the switch devices 54 and 55, and a large current for power supply is conducted. The bus bar 21 and the bus bar 23 are housed in the bus bar support member 25 in a state of being aligned in the switch device arranging direction (direction W1), which is the direction in which the plurality of switch devices are arranged. The bus bar 22 is installed on the opposite side of the bus bar 21 and the bus bar 23 from the switch device. The bus bar 22 is installed on the bus bar side, in other words, on the opposite side of the switch device, so as to overlap the bus bar 21 and the bus bar 23. The bus bar support member 25 and the terminal block unit 14 may be integrally formed as one member, or separate members may be integrally fixed.

The bus bar 21 includes a main body portion 21a elongated in the direction in which the switch devices are arranged, connection terminal portions 21a1 and 21a2 protruding from the main body portion 21a, and an electrical connection portion 21b provided at one end of the main body portion 21a. The direction in which the main body portion 21a extends elongated is along the switch device arranging direction in which the plurality of switch devices are arranged. The connection terminal portion of the bus bar 21 is a portion located on the tip end side of the leg portion protruding outward from a predetermined position on the outer edge of the main body portion 21a having a rectangular plate shape. The bus bar 21 includes a number of connection terminal portions and legs that correspond to the number of power terminal portions in the switch device to be connected. The direction in which each leg portion of the bus bar 21 projects, the shape, the bending angle, and the number of times of bending are set depending on the position of the power terminal portion to be connected.

The electrical connection portion 21b is coupled to the first input/output terminal 41 at one end of the main body portion 21a, so that a large current flows. The connection terminal portion 21a1 and the connection terminal portion 21a2 are rectangular portions that are provided at intervals along the switching device arranging direction and project upward. Furthermore, the connection terminal portion 21a1 and the connection terminal portion 21a2 are provided so as to be aligned with respect to the arrangement direction of the switch device and the bus bar, in other words, the vertical direction to both the vertical direction and the switch device arrangement direction. ing. The connection terminal portion 21a1 is a terminal portion that is coupled to the power line portion 542 of the switch device 54 that is located closest to the electrical connection portion 21b. The connection terminal portion 21a2 is a terminal portion that is coupled to the power line portion 542 of the switch device 54 located at the second closest position from the electrical connection portion 21b.

The bus bar 21 includes an extension portion 21b1 that extends outward by a predetermined length with respect to the electrical connection portion 21b that is in contact with the first input/output terminal 41 in the bus bar 21. The extension portion 21b1 is a part of the bus bar 21 that extends to the side opposite to the main body portion 21a of the bus bar 21 that connects the substrate 51 or the electrical component and the first input/output terminal 41 with respect to the electrical connection portion 21b. .. The extension portion 21b1 may be a portion that extends outward beyond the electrical connection portion 21b so as to extend the main body portion 21a, or further extends outward from the electrical connection portion 21b in a direction intersecting with the main body portion 21a. It may be a part. With such a configuration, a current flowing from the main body portion 21a toward the first input/output terminal 41 forms a path toward the electric load 17 via the electric connection portion 21b and the first input/output terminal 41.

That is, the extension portion 21b1 is a portion formed of a conductive material, but is a portion deviated from the current path. The extension portion 21b1 is a portion protruding outside the current path in the bus bar 21 so as to be separated from the current path. The current path is a path that connects an upstream portion and a downstream portion of the bus bar 21 where current flows. The current path of the bus bar 21 is a path connecting the connection terminal portions 21a1 and 21a2 and the electric connection portion 21b. The extension portion 21b1 is a portion protruding from the upstream end portion or the downstream end portion of the current path of the bus bar 21 to the outside of the current path. The extension portion 21b1 is installed so that heat can be transferred to the base 30.

The extension portion 21b1 is located in a portion where a current does not easily flow, and has a much smaller amount of current than the main body portion 21a and the electrical connection portion 21b, and thus the heat generation due to the current is very small. Due to this action, the temperature of the extension portion 21b1 becomes lower than the other energized portions of the bus bar 21, so that the heat of the bus bar 21 is easily transferred to the extension portion 21b1 and is radiated to the outside from the extension portion 21b1. The extension portion 21b1 is thermally connected to the base 30 via the terminal block unit 14A. Therefore, the heat released from the extension portion 21b1 to the outside moves to the base 30 via the terminal block unit 14A and is further released to the vehicle side member 19 via the stay 32. The extension portion 21b1 is installed so as to be capable of heat transfer with respect to the base 30 at a position separated from a heat dissipation wall 31 on which an electric component such as a switch device is provided so as to be heat transferable.

The outer peripheral edge of the extension portion 21b1 is surrounded by the side wall forming the terminal block unit 14A. Since this side wall is made of an insulating material, it contributes to secure an insulation distance from the extension 21b1. The extension portion 21b1 is provided so as not to protrude outside the outer ends of the plurality of stays 32 in the base 30. The extension portion 21b1 is provided so as not to protrude outside the outer ends of the stays 32a and the stays 32b that are closest to each other among the plurality of stays 32.

The extension portion 21b1 is provided such that the outer end of the extension portion 21b1 is located on the outer frame AR1 illustrated by a chain double-dashed line in FIGS. 1 and 2, or the entire extension portion 21b1 is included inside the outer frame AR1. Has been. Therefore, locating the extension 21b1 in this area means installing the extension 21b1 in the dead space of the battery pack 1. As described above, the extension portion 21b1 is a portion that protrudes to the outside of the current path in the bus bar 21 so as to be out of the current path in the range that does not extend outside the outer peripheral edge of the housing of the battery pack 1. The installation portion of the extension portion 21b1 is a portion where functional portions such as a fixing portion and a current-carrying portion of the battery pack 1 do not exist, and does not protrude outside the outermost portion of the battery pack 1. The extension portion 21b1 is provided in the dead space of the battery pack 1 at such a place.

The extension portion 21b1 is preferably configured such that the cross-sectional area of the extension portion 21b1 is equal to or larger than the cross-sectional area of the portion where the current density is maximum in the current path of the bus bar 21. The current density is the value of the current flowing per unit cross-sectional area, and the part where the current density is maximum is, for example, the main body portion 21a in the bus bar 21 through which a large current flows. The main body portion 21a is a portion where currents from a plurality of current paths such as the connection terminal portion 21a1 and the connection terminal portion 21a2 merge. In addition, it is preferable that the surface area of the extension portion 21b1 be equal to or larger than the surface area of the portion of the current path of the bus bar 21 where the current density is maximum. In addition, the extension portion 21b1 is preferably a portion where the cross-sectional area or surface area of the bus bar 21 is maximum.

The bus bar 23 includes a main body portion 23a elongated in the direction in which the switch devices are aligned, connection terminal portions 23a1 and 23a2 protruding from the main body portion 23a, and a large current terminal portion 23b provided at the other end of the main body portion 23a. Prepare The direction in which the main body portion 23a extends elongated is along the direction in which the switch devices are arranged. The connection terminal portion of the bus bar 23 is a portion located on the tip end side of the leg portion protruding outward from a predetermined position on the outer edge of the main body portion 23a having a rectangular plate shape. The bus bar 23 includes a number of connection terminal portions and legs corresponding to the number of power terminal portions in the switch device to be connected. The direction in which each leg of the bus bar 23 projects, the shape, the bending angle, and the number of times of bending are set depending on the position of the power terminal portion to be connected.

The large current terminal portion 23b is connected to the input/output terminals connected to the plurality of cells at the other end of the main body portion 23a, so that a large current flows. The connection terminal portion 23a1 and the connection terminal portion 23a2 are rectangular portions that are provided at intervals along the direction in which the switch devices are arranged and project upward. Further, the connection terminal portion 23a1 and the connection terminal portion 23a2 are provided so as to be aligned with respect to the arrangement direction of the switch device and the bus bar, in other words, the direction perpendicular to both the vertical direction and the switch device arrangement direction. ing. The connection terminal portion 23a2 is a terminal portion that is coupled to the power line portion 552 of the switch device 55 that is located closest to the large current terminal portion 23b. The connection terminal portion 23a2 is a terminal portion that is coupled to the power line portion 552 of the switch device 55 located at the second closest position from the large current terminal portion 23b.

The bus bar 22 is provided at one end of the main body portion 22a, the main body portion 22a elongated in the direction in which the switch devices are arranged, the connection terminal portion 22b1, the connection terminal portion 22b2, the connection terminal portion 22b3, and the connection terminal portion 22b4 that respectively project from the main body portion 22a. And an electrical connection portion 22d. The direction in which the main body portion 22a extends slenderly is along the direction in which the switch devices are arranged. The connection terminal portion of the bus bar 22 is a portion located on the tip end side of the leg portion that projects outward from a predetermined position on the outer edge of the main body portion 22a having a rectangular plate shape. The bus bar 22 includes a number of connection terminal portions and legs corresponding to the number of power terminal portions in the switch device to be connected. The direction in which each leg of the bus bar 22 projects, the shape, the bending angle, and the number of times of bending are set depending on the position of the power terminal portion to be connected.

The electrical connection portion 22d is coupled to the second input/output terminal 42 at one end of the main body portion 22a, so that a large current is conducted. The connection terminal portion 22b1 and the connection terminal portion 22b2 are located at positions corresponding to the switch device 54 and are provided at intervals along the direction in which the switch devices are aligned, and are located on the tip side of the bent leg portions that project upward. It is a part. Further, the connection terminal portion 22b1 and the connection terminal portion 22b2 are connected to the connection terminal portion 21a1 and the connection terminal portion 21a2 in the arrangement direction of the switch device and the bus bar, in other words, in the direction perpendicular to both the vertical direction and the switch device arrangement direction. They are provided so that they are aligned. The connection terminal portion 22b1 is a terminal portion that is coupled to the power line portion 542 of the switch device 54 that is located closest to the electrical connection portion 22d. The connection terminal portion 22b2 is a terminal portion that is coupled to the power line portion 542 of the switch device 54 located at the second closest position from the electrical connection portion 22d.

The connection terminal portion 22b3 and the connection terminal portion 22b4 are located at positions corresponding to the switch device 55 and are provided at intervals along the switch device alignment direction, and are located on the tip side of the bent leg portions that project upward. It is a part. Further, the connection terminal portion 22b3 and the connection terminal portion 22b4 are aligned with the connection terminal portion 23a1 and the connection terminal portion 23a2 in a direction perpendicular to both the vertical direction and the switch device arrangement direction, in other words, regarding the arrangement direction of the switch device and the bus bar. It is provided so as to be in a different position. The connection terminal portion 22b4 is a terminal portion that is coupled to the power line portion 552 of the switch device 55 that is located closest to the large current terminal portion 23b. The connection terminal portion 22b3 is a terminal portion that is coupled to the power line portion 552 of the switch device 55 located at the second closest position from the large current terminal portion 23b.

The bus bar 22 includes an extension portion 22d1 that extends outward by a predetermined length with respect to the electrical connection portion 22b that is in contact with the second input/output terminal 42 in the bus bar 22. The extension portion 22d1 is a part of the bus bar 22 that extends to the side opposite to the main body portion 22a of the bus bar 22 that connects the substrate 51 or the electric component and the second input/output terminal 42 with respect to the electrical connection portion 22d. .. The extension portion 22d1 may be a portion that extends outward beyond the electrical connection portion 22d so as to extend the main body portion 22a, or further extends outward from the electrical connection portion 22d in a direction intersecting with the main body portion 22a. It may be a part. With such a configuration, a current flowing from the main body portion 22a toward the second input/output terminal 42 forms a path that flows toward the generator motor 15 via the electrical connection portion 22d and the second input/output terminal 42.

That is, the extension portion 22d1 is a portion formed of a conductive material, but is a portion deviated from the current path. The extension portion 22d1 is a portion protruding outside the current path in the bus bar 22 so as to be separated from the current path. The current path is a path connecting the upstream portion and the downstream portion of the bus bar 22 through which the current flows. The current path of the bus bar 22 is a path connecting the connection terminal portions 22b1, 22b2, 22b3, 22b4 and the electrical connection portion 22d. The extension 22d1 is installed so that heat can be transferred to the base 30. The extension portion 22d1 is a portion protruding from the upstream end portion or the downstream end portion of the current path of the bus bar 22 to the outside of the current path.

The extension portion 22d1 is located in a portion where a current does not easily flow, and the amount of current is very small compared to the main body portion 22a and the electrical connection portion 22d, so that the heat generation due to the current is very small. Due to this action, the temperature of the extension portion 22d1 becomes lower than the other energized portions of the bus bar 22, so that the heat of the bus bar 22 is easily transferred to the extension portion 22d1 and is radiated to the outside from the extension portion 22d1. The extension portion 21b1 is thermally connected to the base 30 via the terminal block unit 14B. Therefore, the heat released from the extension portion 22d1 to the outside moves to the base 30 via the terminal block unit 14B and is further released to the vehicle-side member 19 via the stay 32. The extension portion 22d1 is installed so as to be capable of heat transfer with respect to the base 30 at a position separated from a heat dissipation wall 31 on which an electric component such as a switch device is provided so as to be heat transferable.

The outer peripheral edge of the extension portion 22d1 is surrounded by the side wall forming the terminal block unit 14B. Since the side wall is made of an insulating material, it contributes to secure an insulation distance from the extension 22d1. The extension portion 22d1 is provided so as not to project outside the outer ends of the plurality of stays 32 in the base 30. The extension portion 22d1 is provided so as not to project outside of the outer end of the stay 32a located closest to the plurality of stays 32.

The extension portion 22d1 is provided such that the outer end of the extension portion 22d1 is located on the outer frame AR1 illustrated by a chain double-dashed line in FIGS. 1 and 2, or the entire extension portion 22d1 is included inside the outer frame AR1. Has been. Therefore, locating the extension 22d1 in this area means installing the extension 22d1 in the dead space of the battery pack 1. As described above, the extension portion 22d1 is a portion that protrudes outside the current path in the bus bar 22 so as to be out of the current path in the range that does not extend outside the outer peripheral edge of the housing of the battery pack 1. The installation portion of the extension portion 22d1 is a portion where functional portions such as a fixing portion and a current-carrying portion of the battery pack 1 do not exist, and does not protrude outside the outermost portion of the battery pack 1. The extension portion 22d1 is provided in the dead space of the battery pack 1 at such a location.

The extension 22d1 is preferably configured such that the cross-sectional area of the extension 22d1 is equal to or larger than the cross-sectional area of the portion of the bus bar 22 where the current density is maximum. The current density is the value of the current flowing per unit cross-sectional area, and the part where the current density is maximum is, for example, the main body portion 22a in the bus bar 22 through which a large current flows. The main body portion 22a is a portion where currents from a plurality of current paths such as the connection terminal portion 22b1, the connection terminal portion 22b2, the connection terminal portion 22b3 and the connection terminal portion 22b4 join together. Further, it is preferable that the surface area of the extension portion 22d1 be equal to or larger than the surface area of the portion of the bus bar 22 where the current density is maximum in the current path. Further, it is preferable that the extension portion 22d1 is a portion having the largest cross-sectional area or surface area in the bus bar 22.

Each connection terminal portion of the bus bar 21, the bus bar 22, and the bus bar 23 is a portion connected to the power line portion 542 or the power line portion 552 which is a component side terminal of the switch device. The plurality of bus bars 21 and 22 are arranged side by side such that the surfaces of the main body portions thereof face each other and overlap in the orthogonal direction orthogonal to the surfaces of the main body portions 21a and 22a. The plurality of bus bars 22 and the bus bars 23 are arranged side by side such that the surfaces of the main body portions thereof face each other and overlap in the orthogonal direction orthogonal to the surfaces of the main body portions 22a and 23a. This orthogonal direction is also the direction along which the switch device and the bus bar are arranged. The plurality of bus bars 21 and 23 are arranged side by side in the direction along the surface of the main body of each other. The main body portion 21a of the bus bar 21 and the main body portion 23a of the bus bar 23 are arranged side by side in the direction along the surface of the main body portion.

The connection terminal portion 22b1 and the connection terminal portion 22b2 are configured to project toward the switch device 54 side from the main body portion 22a and reach the component side terminal. The connection terminal portion 22b3 and the connection terminal portion 22b4 are configured to project toward the switch device 55 side with respect to the main body portion 22a and reach the component side terminal.

The electric component unit in the battery pack 1 includes a bus bar which is a connecting member, and a plurality of electric components each having a component side terminal connected to the connection terminal portion of the bus bar. The electric component unit can hold each bus bar at a desired position by including the bus bar housing case that supports or houses the bus bar.

The battery pack 1 includes a battery unit 20, a base 30, an electric component unit, and an electric circuit 50. The battery unit 20, the electric component unit, and the electric circuit 50 are mounted on the base 30. The electric circuit 50 is a functional component including a substrate 51 and a plurality of electric components 52. The base 30 has a concave container part for installing the battery unit 20. The base 30 accommodates only a part of the battery unit 20, for example, only the lower part in the container part, and the remaining part of the battery unit 20, for example, the upper part, projects from the base 30. The battery unit 20, the electric component unit, and the electric circuit 50 are fixed to the base 30 by a plurality of fastening members such as screws or bolts.

The battery unit 20 has a battery case that houses a plurality of cells. The battery case is made of electrically insulating resin. The battery case is a part of a container that houses a plurality of cells. The battery case fixes a plurality of cells to each other. Furthermore, the battery case is also a fixing member that fixes the plurality of unit cells to the base 30. The battery case has a plurality of brackets for fixing the battery unit 20 to the base 30.

The battery unit 20 has a monitor module. The monitor module has an electrically insulating resin member and a monitor connection member connected to the plurality of unit cells. The monitor connecting member is embedded in the resin member by insert molding. The monitor connecting member connects the unit cell and the electric circuit 50 through the resin member. The monitor module has a water sensor including a plurality of water detection electrodes. The monitor module is arranged along one surface of the battery case.

The base 30 is made of a conductive metal. The base 30 is also called a carrier. The base 30 can be formed by, for example, aluminum-die casting. The base 30 has high thermal conductivity and high rigidity. The base 30 includes a container portion that receives the battery unit 20. The base 30 has a plurality of stays 32a, 32b, 32c, 32d, 32e. The plurality of stays 32a to 32e are collectively referred to as a stay 32. The stay 32 is a fixing portion fixed to the vehicle-side member 19 for fixing the battery pack 1 to the vehicle. The vehicle-side member 19 is a part of the vehicle on which the battery pack 1 is mounted to fix the battery pack 1, and is, for example, a plate-shaped frame or panel. The stay 32 is provided with a mounting hole for inserting a bolt or the like, which is an example of a fixing means for fixing the stay 32 to the vehicle-side member 19. The stay 32 may be fixed to the vehicle-side member 19 by a fixing means such as welding.

The electric component unit provides a power path extending from the power terminal of the battery unit 20. The electric component unit has an electrically insulating resin member and a power connecting member connected to the battery unit 20. The electric component unit is fixed on the base 30. The electrical component unit has at least two power connection members. One power connection member is provided between one power terminal of the battery unit 20 and another power terminal to provide an electrical connection. The bus bar unit 40 is also a member that connects the plurality of input/output terminals 41, 42, 43, the battery unit 20, and the electric circuit 50.

The electric circuit 50 is fixed on the base 30. The electric circuit 50 is provided so as to spread beside the battery unit 20. The battery unit 20 is installed in one corner of the base 30 having a substantially quadrilateral shape. The electric circuit 50 occupies a range that spreads laterally of the battery unit 20 on the base 30.

The board 51 is a control board provided with a wiring pattern. The substrate 51 extends over the horizontal range occupied by the electric circuit 50. The substrate 51 is installed on the heat dissipation wall 31 provided on the base 30. The substrate 51 and the heat dissipation wall 31 are in direct contact with each other so that heat can be transferred from the substrate 51 to the heat dissipation wall 31, or indirectly through a heat conductive material such as a sheet or gel having excellent heat conductivity. Are bonded in a state of being in thermal contact with each other. The heat dissipation wall 31 and the stay 32 are integrally formed so that heat can be transferred through the wall forming the base 30. Therefore, the battery pack 1 is provided with a heat dissipation path through which the heat transferred from the substrate 51 to the heat dissipation wall 31 is released to the vehicle-side member 19 through the stay 32 provided on the side wall of the base 30. The battery pack 1 also includes a heat dissipation path through which the heat transferred from the substrate 51 to the heat dissipation wall 31 is released into the air from the heat dissipation wall 31.

The heat generated by the switch device 53, which controls a relatively low current, moves to the heat dissipation wall 31 of the base 30 via the substrate 51, and can be moved downward from the heat dissipation wall 31 along a plurality of side walls. Further, the heat is transmitted from one side wall to the vehicle-side member 19 via the stay 32 at the lower portion and is released to the outside. According to this heat dissipation path, it is possible to configure a path extending from the heat dissipation wall 31 to the plurality of side walls along the heat dissipation wall 31. Therefore, according to the battery pack 1, it is possible to configure, as the heat dissipation path of the heat generating element, the heat transfer path through which the solid having higher thermal conductivity than air is transmitted.

The substrate 51 is a single substrate. A plurality of electric components 52 are arranged on the substrate 51. The electrical component 52 is one of the articles that generate heat in the battery pack 1 and corresponds to a heating element. The substrate 51 has a plurality of connecting portions. Some or all of the plurality of connecting portions provide a connection between the power connecting member of the bus bar unit 40 and the electric component 52. The electric circuit 50 is connected to a plurality of cells. The plurality of electrical components 52 provide a controller. The control device monitors the voltage of each of the plurality of unit cells included in the battery unit 20. The control device monitors the charge state and the discharge state of each of the plurality of unit cells. The control device appropriately controls the state of charge of each of the plurality of unit cells. The unit cell is, for example, a nickel hydrogen secondary battery, a lithium ion battery, or an organic radical battery.

The plurality of electric components 52 include a switch device 53, a switch device 54, and a switch device 55. Each of the switch devices 53 to 55 is a device that is on/off controlled by the electric circuit 50. The switch devices 54 and 55 can intermittently control the output of the battery unit 20. The switch devices 54 and 55 connect and disconnect the current supplied from the total plus terminal of the battery unit 20. The switch device 53 is a weak electric component through which a smaller current than the switch devices 54 and 55 flows. The switch device 53 is mounted on the substrate 51. Each of the switch devices 53 to 55 is a semiconductor switch widely known as a transistor, a MOSFET, an IGBT or the like. Further, each of the switch devices 53 to 55 may be a mechanical relay that is opened and closed electromagnetically. Each of the switch devices 53 to 55 is one of the electric components 52 that generate heat in the battery pack 1 and corresponds to a heating element. In addition to the switch device, the electrical component that is the heating element includes a resistor.

Water may get into the battery pack 1 when water is spilled on the seat, when an occupant wet with water uses the seat, or when the vehicle is soaked in water. In this case, the battery pack 1 may discharge using water as a discharge path. In this embodiment, a water sensor that detects water in the battery pack 1 and a control device that executes a countermeasure process when water is detected are provided. The controller monitors water ingress into the battery pack 1. The control device takes corrective action when inundation is detected. The countermeasure process is, for example, turning off the breaker element, which is one of the plurality of electric components.

The control system provided by the electric circuit 50 provides a control device that is an electronic control unit (Electronic Control Unit). The control device has at least one arithmetic processing unit (CPU) and at least one memory device (MMR) as a storage medium for storing programs and data. The control device is provided by a microcomputer including a computer-readable storage medium. The storage medium is a non-transitional tangible storage medium that non-temporarily stores a computer-readable program. The storage medium can be provided by a semiconductor memory, a magnetic disk, or the like. The controller may be provided by a computer or a set of computer resources linked by a data communication device. The program causes the control device to function as the device described in the present specification by being executed by the control device, and causes the control device to function to perform the method described in the present specification.

The control system has, as input devices, a plurality of signal sources that supply signals indicating information input to the control device. The control system acquires information by the control device storing the information in the memory device. The control system has a plurality of controlled objects whose operations are controlled by the control device as output devices. The control system controls the operation of the controlled object by converting the information stored in the memory device into a signal and supplying the signal to the controlled object.

The control device, the signal source, and the controlled object included in the control system provide various elements. At least some of these elements can be referred to as blocks for performing functions. In another aspect, at least some of those elements can be referred to as modules, or sections, that are interpreted as a configuration. Furthermore, the elements included in the control system can also be called means for realizing their functions only when they are intended.

The means and/or functions provided by the control system can be provided by software recorded in a substantive memory device and a computer executing the software, only software, only hardware, or a combination thereof. For example, if the controller is provided by an electronic circuit that is hardware, it can be provided by a digital circuit that includes multiple logic circuits, or an analog circuit. The electric circuit 50 may include a circuit as an inverter and/or a converter, and a monitor circuit for observing the voltages of a plurality of unit cells.

The base 30 has a plate shape or a dish shape. The base 30 has a shape that can be called a shallow dish shape or a shallow cup shape. The shape of the base 30 is a downward convex shape and a concave shape from the top in the container portion. The base 30 has a high rigidity against an external force that tends to bend it. The base 30 has a high rigidity that opposes an external force in the lateral direction that opens the container portion, particularly in the width direction W1. The base 30 has high rigidity in the direction in which the plurality of unit cells significantly expand.

On the heat dissipation wall 31 of the base 30, a part of the electric component 52 is arranged via the substrate 51. Some of the electric components 52 are components that require heat dissipation. For example, the switch device 53 in the electric circuit 50 is arranged on the heat dissipation wall 31. An insulating sheet is installed between the heat dissipation wall 31 and the electric component 52 and between the heat dissipation wall 31 and the substrate 51. With this configuration, the heat of the electric component 52 moves to the heat dissipation wall 31 via the insulating sheet. In the base 30, the heat dissipation wall 31 is convex upward and concave from below. The heat radiating wall 31 provides a concave heat radiating portion from below on the lower surface of the base 30.

On the base 30, a strong electric part in which switch devices 54 and 55 for controlling the electric current for the unit cells are installed, and a weak electric part in which electric parts such as a switch device 53 through which a current smaller than the strong electric part flows are installed. Is provided. The high-power unit occupies the area where the switch devices 54 and 55 are installed, for example. The low-power portion occupies an area where electrical components other than the switch devices 54 and 55 are installed, for example.

As shown in FIG. 9, the switch devices 54 and 55 are provided so as to be able to move heat with respect to the heat dissipation wall 31. Each of the bus bars 21 and 22 connects the switch device 54 or the switch device 55 and the base 30 in a heat-movable manner via a sheet-shaped member 91 having heat conductivity. The member 91 is an insulating member having electrical insulation and thermal conductivity. The bus bar 24 is movably connected to the vehicle-side member 19 via the base 30. Each of the bus bars 21, 22 is movably connected to a vehicle-side member 19 such as a vehicle harness via a harness connecting member 19a having thermal conductivity.

The base 30 is heat-movably installed on the vehicle-side member 19 such as the vehicle underbody via the stay 32. The substrate 51 is installed so as to be able to transfer heat to the heat dissipation wall 31 of the base 30. The switch devices 54 and 55 are installed so that heat can be transferred to the heat dissipation wall 31. As shown in FIG. 7, a sheet-shaped member 91 is sandwiched between the electric connection portions 21b, 22d, 24b and the extension portions 21b1, 22d1, 24b1 and each terminal block unit 14A, 14B, 14C in each bus bar. ing. As shown in FIG. 9, the extension portions 21b1 and 22d1 are connected to the base 30 via a sheet-shaped member 91 so as to be capable of heat transfer.

As shown by arrows in FIG. 9, the battery pack 1 includes a heat radiation path through which heat generated by the switch devices 53, 54, 55 moves from the base 30 to the vehicle-side member 19 via the substrate 51 and the heat radiation wall 31. .. Further, there is provided a heat radiation path through which heat generated by the switch devices 54 and 55 moves to the bus bar and moves from the bus bar to the vehicle-side member 19 via the harness connecting member 19a. The battery pack 1 has a heat radiation path through which the heat of the bus bar moves from the extended portions 21b1, 22d1 deviated from the current path to the base 30 via the member 91 and is radiated to the vehicle-side member 19. According to the first embodiment, it is possible to construct a heat dissipation path that moves the heat of the bus bar to the base 30 through the extension portions 21b1 and 22d1 without passing through electrical parts such as a switch device.

According to a study by the inventor, a large current flows through the switch devices 54 and 55, so that the switch devices 54 and 55 are likely to reach a high temperature, and the heat generation of the switch devices 54 and 55 and the large current flowing through the bus bar also cause the bus bar to reach a high temperature. Since the switch devices 54, 55 and the substrate 51 have a temperature close to 100° C., the temperature difference with the temperature of the bus bar is small, but the temperature of the vehicle-side member 19 is about 60° C., so that the bus bar and the vehicle-side member 19 are separated from each other. It is known that the temperature difference can be secured to the extent that heat transfer can be expected. According to the heat dissipation path from the bus bar included in the battery pack 1, the heat generated in the bus bar is moved to the vehicle-side member 19 having a large temperature difference from the bus bar without passing through the switch devices 54, 55 and the substrate 51. Can be increased. Further, the heat of the bus bar is moved to the vehicle-side member 19 via the extension portion without passing through the switch devices 54, 55 and the substrate 51, whereby the length of the heat transfer path can be shortened and the heat resistance can be suppressed. Can also contribute.

As shown in FIG. 10, the periphery of each bus bar 21, 22, 23, 24 is surrounded by an insulating member 92 having an insulating property in order to prevent the bus bars from coming into contact with each other to cause a short circuit. A clearance is preferably provided between the outer surface of each bus bar and the inner surface of the insulating member 92. The insulating member 92 is preferably formed of, for example, polybutylene terephthalate resin. It is preferable that the tip of each bus bar is located inside the tip of the insulating member 92, and the tip of the insulating member 92 projects outward. Since the periphery of each bus bar 21, 22, 23, 24 is surrounded by the insulating member 92, it has a structure that is thermally sealed. Even with such a structure that is thermally sealed, the present disclosure aims to improve heat dissipation.

Next, effects obtained by the battery pack 1 of the first embodiment will be described. The battery pack 1 is a base having a battery, a housing that accommodates the battery, and a part of the housing that has a heat dissipation wall 31 and that is attached to the vehicle-side member 19 so as to be capable of heat transfer. 30 and electric components provided so as to be capable of heat transfer with respect to the heat dissipation wall 31. The battery pack 1 includes bus bars 21, 22 and 24 that are provided so as to be able to transfer heat to the heat dissipation wall 31 and that are electrically connected to the electric components. The bus bars 21, 22, and 24 extend outside the current path in the bus bar so as not to extend outside the outer peripheral edge of the housing, and extend outside the current path so that they can be thermally transferred to the base 30. It has parts 21b1, 22d1 and 24b1. The battery pack 1 has the following effects if at least one of the bus bars 21, 22 and 24 is provided with an extension.

According to the battery pack 1, the extension portions 21b1, 22d1 and 24b1 formed so as to deviate from the current paths in the bus bars 21, 22 and 24 are installed so as to be able to conduct heat to the base 30. That is, a heat radiation path for moving the heat generated by the bus bars 21, 22, 24 to the base 30 without passing through the electric components or the heat radiation wall 31 is provided. As a result, the amount of heat released from the bus bars 21, 22, 24 to the outside can be increased. According to this heat dissipation path, heat is dissipated to the base 30 capable of ensuring a temperature difference with the bus bars 21, 22, 24. Therefore, the heat transfer amount released from the bus bars 21, 22, 24 to the base 30 is calculated according to Patent Document 1 It can be increased as compared with the conventional technique described in 1. Each of the extension portions 21b1, 22d1 and 24b1 is installed in a range that does not extend outside the outer peripheral edge of the housing including the stay 32, the base 30, and the like that are attachment portions. For this reason, in the battery pack 1, it is possible to install the extension part as the heat dissipation part of the bus bar in the dead space, which is a space that does not particularly function. Therefore, according to the battery pack 1, it is possible to improve the heat dissipation of the bus bar and effectively use the space.

Since the battery pack 1 improves the heat dissipation of the bus bar in this way, the allowable current value that can be passed through the bus bar can be increased. Further, in the battery pack 1, since the allowable current value per unit cross-sectional area of the bus bar is improved, it is possible to improve the operating current in the battery pack 1 and reduce the size and weight of the bus bar.

The extension portions 21b1, 22d1 and 24b1 are portions protruding from the upstream end portion or the downstream end portion of the current path of the bus bar to the outside of the current path. With this configuration, it is possible to construct a heat dissipation path that radiates the heat of the bus bar to the base 30 at a position apart from the electrical components such as the switch device. Thereby, the heat of the bus bar can be released over a wide range of the bus bar, and by providing the heat release path away from the portion of the base 30 that radiates heat from the electric component, a heat radiating path that is less affected by the heat radiated from the electric component is provided. be able to.

The cross-sectional areas of the extension portions 21b1, 22d1 and 24b1 are set to be equal to or larger than the cross-sectional area of the portion where the current density is maximum in the current path of the bus bar. According to this configuration, the extension having a larger heat capacity than the portion of the bus bar that generates the most heat can be provided, so that the battery pack 1 in which the amount of heat released from the extension to the base 30 is increased can be provided.

The surface areas of the extension portions 21b1, 22d1 and 24b1 are set to be equal to or larger than the surface area of the portion where the current density is maximum in the current path of the bus bar. According to this configuration, the extension having a larger heat capacity than the portion of the bus bar that generates the most heat can be provided, so that the battery pack 1 in which the amount of heat released from the extension to the base 30 is increased can be provided.

The cross-sectional area or surface area of the extension portions 21b1, 22d1 and 24b1 is the largest portion in the bus bar. According to this structure, the extension part having a larger heat capacity than any other part of the bus bar can be provided, so that the battery pack 1 in which the amount of heat radiated from the extension part to the base 30 is increased can be provided.

The extension portions 21b1, 22d1 and 24b1 are installed so as to be capable of heat transfer with respect to the base 30 at a position closer to the outer peripheral edge of the base 30 with respect to a heat dissipation wall 31 provided with heat transfer of electrical components. According to this configuration, since heat can be radiated from the extension portion to the base 30 at a position away from the electric component, it is possible to provide a heat radiating path that is less affected by the heat radiated from the electric component. In addition, it is possible to construct a heat dissipation path for the bus bar that has little heat effect on the electrical components.

The electrical components are switch devices 54 and 55 that control current. According to this, it is possible to construct a heat dissipation path of the bus bar that suppresses interference with the heat dissipation path of the switch device that tends to become hot. As a result, the battery pack 1 that can contribute to the suppression of deterioration of the switch device against heat can be provided.

The extension parts 21b1, 22d1 and 24b1 are installed so as to be capable of heat transfer with respect to the base 30 via a member 91 having electrical insulation. With this configuration, the base 30 can be made of a material having excellent heat conduction, and the battery pack 1 that promotes heat dissipation from the extension portion to the vehicle-side member 19 can be provided.

The disclosed heat dissipation device for a bus bar includes a base 30 that is a part of a housing and is installed so as to be capable of heat transfer with respect to an external member; The bus bars 21, 22, and 24 are provided so as to be able to transfer heat to the wall 31 and electrically connected to the electric components. The bus bars 21, 22, 24 project outside the current path so as to be out of the current path in the bus bars 21, 22, 24 within a range that does not extend outside the outer peripheral edge of the housing, and heat transfer to the base 30 is possible. Has an extension installed at.

According to this heat dissipation device for the bus bar, the extension part formed so as to be away from the current path in the bus bar 21, 22, 24 is installed so as to be able to conduct heat to the base 30 which is a part of the housing. According to this configuration, since the heat radiation path for moving the heat generated by the bus bars 21, 22, 24 to the base 30 is provided without passing through the electric components, the heat radiation amount from the bus bars 21, 22, 24 can be increased. According to this heat dissipation path, heat is dissipated to the base 30 in which a temperature difference with the bus bars 21, 22, 24 can be secured, so that the amount of heat transferred from the bus bars 21, 22, 24 to the base can be increased. Therefore, it is possible to provide a heat dissipation device for the busbars that can improve the heat dissipation of the busbars 21, 22, 24 and effectively use the space.

(Second embodiment)
In the second embodiment, a heat transfer path from a switch device or a bus bar, which is another form of the first embodiment, will be described with reference to FIG. 11. The second embodiment is different from the first embodiment in that the extension parts 121b1 and 122d1 are not extended at the end of the bus bar, but are branched from a part in the middle of the bus bar. To do. The second embodiment has the same configuration as that of the first embodiment except for this configuration, and has the same operational effect. That is, in the following description, contents different from the first embodiment will be described.

As shown in FIG. 11, the bus bars 21 and 22 are respectively provided with extension portions 121b1 and 122d1 extending from the middle of the main body of the bus bar so as to branch. The extension portion 121b1 is a portion protruding outside the current path so as to branch in the middle of the current path of the bus bar 21. The extension portion 122d1 is a portion protruding outside the current path so as to branch in the middle of the current path of the bus bar 22. The bus bars 21 and 22 are connected to the vehicle-side member 19 via the harness connecting member 19a in a heat-movable manner. The extension parts 121b1 and 122d1 are movably connected to the heat dissipation wall 31 via a sheet-shaped member 91 having heat conductivity. The extension parts 121b1 and 122d1 connect the switch device 54 or the switch device 55 and the base 30 via the member 91 in a heat-movable manner.

As shown by an arrow in FIG. 11, the battery pack 1 includes a heat dissipation path through which heat generated by the switch devices 54 and 55 moves from the base 30 to the vehicle-side member 19 via the substrate 51 and the heat dissipation wall 31. Further, the heat generated by the switch devices 54, 55 moves to the bus bar, and moves to the base 30 via the member 91 from the extension parts 121b1, 122d1 which are out of the current path in the middle of the bus bar, and is radiated to the vehicle side member 19. It has a route. According to the second embodiment, it is possible to construct a heat dissipation path for moving the heat of the bus bar to the base 30 through the extension parts 121b1 and 122d1 without passing through electrical parts such as the switch device. According to the extension portion of the second embodiment, it is possible to provide a heat dissipation path that shortens the heat transfer distance until the heat of the bus bar moves to the base, which can contribute to increasing heat dissipation efficiency.

According to the second embodiment, the extension portions 121b1 and 122d1 are portions protruding outside the current path so as to branch in the middle of the current path of the bus bar. According to this configuration, it is possible to construct a heat dissipation path that can shorten the distance that the heat of the bus bar moves. Due to the short heat radiation distance, it is possible to provide the battery pack 1 capable of efficiently releasing the heat of the bus bar.

(Other embodiments)
The disclosure of this specification is not limited to the illustrated embodiments. The disclosure encompasses the illustrated embodiments and variations on them based on them. For example, the disclosure is not limited to the combination of parts and elements shown in the embodiments, and various modifications can be implemented. The disclosure can be implemented in various combinations. The disclosure may have additional parts that may be added to the embodiments. The disclosure includes parts and elements of the embodiments omitted. The disclosure includes replacements or combinations of parts, elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is shown by the description of the claims, and should be understood to include meanings equivalent to the description of the claims and all modifications within the scope.

In the above-described embodiment, the plurality of switch devices installed to be able to move heat to the heat dissipation wall 31 may be a single switch device. Although the switch device is indirectly thermally connected to the heat dissipation wall 31 via the member 90, the member 90 may be made of a solid material having heat conductivity, such as gel or grease. Further, the switch device may be configured to be installed on the substrate 51 in a heat transferable state.

In the above-described embodiment, the stay 32 of the base 30 may not be directly fixed to the vehicle-side member 19. The stay 32 may be fixed to the vehicle-side member 19 via another member so that the stay 32 can be thermally moved to the vehicle-side member 19 so as to be heat-movable.

In the above-described embodiment, the bus bars 21, 22, 24 may be configured not to be directly connected to the electric component. The bus bars 21, 22, 24 may be connected to the electric parts via separate members as long as they are connected to the electric parts so that they can be energized.

The unit cell constituting the battery unit 20 in the above-described embodiment may have, for example, a thin plate-like outer case, and the outer case may be formed of a laminate sheet. The laminate sheet is made of a highly insulating material. The unit cell has, for example, an internal space of a flat container which is sealed by sealing the ends of the folded laminate sheet by heat-sealing the ends. A battery main body including an electrode assembly, an electrolyte, a terminal connecting part, a part of the positive electrode terminal part, and a part of the negative electrode terminal part is built in this internal space. Therefore, in the plurality of cells, the battery main body is housed in a sealed state inside the flat container by sealing the peripheral portion of the flat container. Each unit cell has a pair of electrode terminals drawn outward from the flat container.

As the unit cell that constitutes the battery unit 20 in the above-described embodiment, for example, a unit cell having a cylindrical outer shape may be used.

In the above-described embodiment, the plurality of unit cells forming the battery unit 20 may be installed in a state of being in contact with each other without providing a gap between adjacent unit cells, or a predetermined gap may be provided between the unit cells. You may make it open and install.

11... Cover (housing), 19... Vehicle side member (external member)
20... Battery unit (battery), 21, 22, 24... Bus bar 21b1, 22d1, 24b1, 121b1, 122d1... Extension part 30... Base (housing), 31... Heat dissipation wall, 32... Stay (mounting part)
54, 55... Switch device (electrical component)

Claims (8)

A battery (20) housed in a housing (11, 30),
A base (30) that is a part of the housing and has a mounting portion (32) that has a heat dissipation wall (31) and is arranged so as to be able to transfer heat to the vehicle-side member (19);
Electrical parts (54, 55) that are provided so as to be able to transfer heat to the heat dissipation wall and through which an electric current flows
Bus bars (21, 22 ) that are provided so as to be able to transfer heat to the heat dissipation wall and that are electrically connected to the electric components;
Equipped with
The bus bar protrudes outside the current path so as to be separated from the current path in the bus bar within a range that does not extend outside the outer peripheral edge of the housing, and is an extension part that is heat-transferable with respect to the base. (1 21b1,122d1) have a,
The current path is a path connecting an upstream end and a downstream end of the current in the bus bar,
The extension portion is a portion that is branched from the middle of the rectangular plate-shaped main body portion provided in the middle of the current path and projects outward from the main body portion,
Battery pack heat of the bus bar that are provided by a heat dissipation path to move to the base via the extension portion. The cross-sectional area of the extension, the battery pack according to claim 1 that have been set to be equal to or greater with respect to the cross-sectional area of the portion where the current density is maximum in have you to the current path. The surface area of the extension, the battery pack according to claim 1 or claim 2 current density that is set to be equal to or greater of the surface area of the portion having the maximum in the current path. The cross-sectional area or surface area of the extension, the battery pack according to any one of claims 1 to 3 parts Ru der with the maximum in the bus bar. The extension, claims 1 to 4, wherein the electrical components are installed thermally movably relative to said base with respect to the heat radiating wall provided so as to be heat transfer at the location of the outer periphery side of the said base The battery pack according to any one of 1. The electrical component is a battery pack according to any one of claims 1 to 5 is a switch device for controlling the current. The said extension part is a battery pack as described in any one of Claim 1 to 6 currently installed so that heat transfer is possible with respect to the said base via the insulating member (91) which has an electrically insulating property . A base (30) that is a part of the housing (11, 30) and has a mounting portion (32) that has a heat dissipation wall (31) and is installed so as to be able to transfer heat to an external member (19);
Electrical components (54, 55) that are provided so as to be able to transfer heat to the heat dissipation wall and through which an electric current flows,
A bus bar (21, 22 ) that is provided so as to be able to transfer heat to the heat dissipation wall and that is electrically connected to the electric component;
Equipped with
The bus bar protrudes outside the current path so as to be separated from the current path in the bus bar within a range that does not extend outside the outer peripheral edge of the housing, and is an extension part that is heat-transferable with respect to the base. (1 21b1,122d1) have a,
The current path is a path connecting an upstream end and a downstream end of the current in the bus bar,
The extension portion is a portion that is branched from the middle of the rectangular plate-shaped main body portion provided in the middle of the current path and projects outward from the main body portion,
Bus bar of the heat dissipation device heat of the bus bar that are provided by a heat dissipation path to move to the base via the extension portion.

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