JP2011119102A - Vehicular battery unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent heat effect on a battery pack due to heat dissipation at the operation of an equalizing circuit, and to satisfactorily reduce operation of a cooling fan. <P>SOLUTION: A vehicular battery unit 10 is assembled in an electric vehicle 12. A battery unit 10 includes a battery pack 22, wherein the battery pack 22 has a plurality of batteries 20 combined; a housing 28, in which the battery pack is housed and a cooling air inlet port 24 and a cooling air lead-out port 26 are installed; a cooling fan 30 which introduces cooling air into the housing 28; and an equalizing circuit 32, which equalizes the power storage amount of the plurality of batteries 20, by discharging electric power of the battery 20 which has a relatively high-power storage amount to a resister inside the circuit, when there are variations in the power storage amount for the plurality of batteries 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle battery unit for driving a travel motor provided in a vehicle.

  Vehicles such as electric vehicles (EV) and hybrid vehicles with motors and engines have been developed. In this type of vehicle, a battery unit including an assembled battery in which a plurality of batteries are stacked is employed as a power source for driving a travel motor.

  For example, in an assembled battery using a lithium ion battery, variations in battery characteristics such as voltage or remaining capacity between batteries or battery groups are likely to occur. Therefore, the battery may be overcharged or overdischarged, and an equalizing circuit is used to equalize battery characteristics.

  The assembled battery equalization apparatus disclosed in Patent Document 1 detects battery characteristics in an assembled battery in which a plurality of battery cells are combined, and equalizes the battery characteristics between battery cells or between battery cell groups according to the detection result. An equalizing circuit, a power supply means for supplying power to operate the equalization circuit, and a circuit stop means for stopping the power supply according to a circuit stop condition and stopping the equalization circuit And changing means for changing the circuit stop condition.

  As a result, it is possible to suppress or prevent power consumption in the equalization circuit after the power supply is stopped by the circuit stop unit. It is possible to prevent the situation where equalization is stopped even if necessary.

JP 2008-54416 A

  Incidentally, in general, it is desirable that the operation of the equalization circuit be performed in a state where the battery voltage is stable. For this reason, in the vehicle battery unit, specifically, the equalization circuit is operated during stoppage, idling, or charging.

  Here, when the electric power of the battery having a relatively high charged amount is discharged to the resistance in the equalization circuit, relatively high-temperature heat is generated. Therefore, it is necessary to cool the assembled battery with a cooling fan and to cool the equalizing circuit at the same time so that the assembled battery is not affected by the heat from the equalizing circuit. However, especially in each state such as when the engine is stopped, noise during driving of the cooling fan becomes a problem, and noise countermeasures are required.

  The present invention solves this type of problem, and as much as possible prevents the heat effect on the assembled battery due to the heat generated during the operation of the equalization circuit, and can reduce the operation of the cooling fan satisfactorily. An object of the present invention is to provide a vehicular battery unit.

  The present invention relates to a vehicle battery unit for driving a travel motor provided in a vehicle. The vehicle battery unit includes an assembled battery in which a plurality of batteries are combined, a housing in which the assembled battery is stored, a cooling air introduction port and a cooling air outlet port are provided, and cooling air is introduced into the housing. When there is a variation in the amount of electricity stored between the cooling fan and the plurality of batteries, the amount of electricity stored in the plurality of batteries is equalized by discharging the power of the battery having a relatively high amount of electricity to a resistor in the circuit. And an equalizing circuit.

  In the housing, an equalization circuit is disposed above the assembled battery, at least a part of the cooling air introduction port is located below the assembled battery, and at least one of the cooling air outlet ports. The part is located above the equalization circuit.

  The housing has a substantially cubic shape, and the upper surface of the inner wall extending above the equalization circuit is inclined upward from the cooling air inlet to the cooling air outlet, and the uppermost position of the inner wall upper surface is inclined. It is preferable that the cooling air outlet is provided.

  Further, the assembled battery is formed by stacking a plurality of batteries having a square shape and sandwiched by a pair of plate-shaped holding members from both ends in the stacking direction, and the pair of plate-shaped holding members are separated from the upper surfaces of the plurality of batteries. In addition, it is preferable that the plurality of batteries are integrally connected to each other by a bridge portion extending in the stacking direction, and an equalization circuit is mounted on the bridge portion.

  Furthermore, a mounting plate portion on which the assembled battery is placed is provided inside the housing, and the mounting plate portion includes a plurality of openings that open toward each assembled battery. It is preferable that a passage portion that communicates the cooling air inlet and the plurality of openings is formed below the placement plate portion.

  According to the present invention, the equalization circuit having a relatively high temperature toughness is disposed above the assembled battery. For this reason, an assembled battery becomes difficult to receive the influence by the heat | fever generate | occur | produced at the time of the drive of an equalization circuit.

  Moreover, inside the housing, cooling air is introduced from a cooling air introduction port located below the assembled battery, while the cooling air is discharged from a cooling air outlet port located above the equalization circuit. Yes. Therefore, the cooling air flowing inside the housing can cool the equalizing circuit after cooling the assembled battery. As a result, it is possible to prevent as much as possible the heat effect on the assembled battery due to heat generated during the operation of the equalizing circuit, and to reduce the operation of the cooling fan satisfactorily.

It is a schematic explanatory drawing of the electric vehicle in which the vehicle battery unit which concerns on embodiment of this invention is integrated. It is side surface explanatory drawing of the said battery unit. It is a perspective explanatory view of the battery unit. It is a perspective explanatory view of the assembled battery which constitutes the battery unit. It is explanatory drawing of the equalization circuit which comprises the said battery unit.

  As shown in FIG. 1, a vehicle battery unit 10 according to an embodiment of the present invention is arranged in a floor space 14 of a vehicle, for example, an electric vehicle 12. The underfloor space 14 is partitioned from the cabin 18 via the floor 16. As the vehicle, various vehicles capable of running on a motor, such as an electric vehicle 12 and a hybrid vehicle, can be used.

  The battery unit 10 includes an assembled battery 22 in which a plurality of batteries 20 having a square shape (in FIG. 3 and FIG. 4, for example, but not limited to seven) are combined, and the assembled battery 22 is accommodated. In addition, the housing 28 in which the cooling air introduction port 24 and the cooling air outlet 26 are provided, the cooling fan 30 that introduces the cooling air into the housing 28, and the storage amount of the plurality of batteries 20 vary. In this case, an equalization circuit 32 is provided for equalizing the storage amounts of the plurality of batteries 20 by discharging the power of the battery 20 having a relatively high storage amount to a resistor in the circuit (FIGS. 1 and 2). reference).

  A plurality of the assembled batteries 22 are arranged in the vehicle length direction (arrow L direction) of the electric vehicle 12, for example, in the drawing, for example, in five rows, and in the vehicle width direction (arrow H direction), in FIG. Arranged in two rows. In addition, the number of the assembled batteries 22 is set as needed, and is not limited to this embodiment.

  As shown in FIG. 4, the battery 20 is provided with a pair of battery terminals 34 a and 34 b. The batteries 20 are electrically connected in series via the terminal connection member 36. The plurality of batteries 20 are sandwiched by a pair of plate-like holding members 38a and 38b from both ends in the stacking direction (arrow H direction).

  The pair of plate-shaped holding members 38a and 38b have a square shape, and are spaced apart from the upper surfaces of the plurality of batteries 20 by a distance S and extend along the stacking direction above the plurality of batteries 20. 40a and 40b are integrally connected. An equalizing circuit 32 is mounted on the pair of bridge portions 40a and 40b.

  As shown in FIG. 5, a load including a travel motor 44 is connected to the plurality of assembled batteries 22 via a relay type switch 42 and an inverter 43. In the equalization circuit 32, wirings 46a to 46h are connected to each pole of each battery 20, and an electric resistance 48 and a switch 50 arranged in series are connected between the adjacent wirings 46a and 46b. Similarly, an electrical resistance 48 and a switch 50 are connected between the adjacent wirings 46b and 46c to the wirings 46g and 46h, respectively.

  The equalization circuit 32 includes a control unit 52. The control unit 52 calculates the difference value of the voltage input from each battery 20 and calculates the variation of each difference value. When the magnitude of the variation is equal to or greater than a predetermined value, the control unit 52 selects the battery 20 having a large voltage. Discharge to reduce this variation. For example, when the switch 50 provided between the wirings 46a and 46b is turned on (energized state), the electric power charged in the battery 20 connected to the wirings 46a and 46b is consumed by the electrical resistor 48. The voltage of the battery 20 decreases.

  As shown in FIGS. 2 and 3, the housing 28 has a substantially cubic shape, and an equalization circuit 32 is disposed above the assembled battery 22 in the housing 28. At least a part of the cooling air inlet 24 is located below the assembled battery 22, and at least a part of the cooling air outlet 26 is located above the equalization circuit 32. The cooling air introduction port 24 is opened to the cabin 18, for example, while the cooling air outlet 26 is opened to the rear of the vehicle body via a hose (not shown), for example.

  The inner wall upper surface 54 of the housing 28 is inclined upward from the cooling air inlet 24 toward the cooling air outlet 26 (in the direction of arrow L1 in FIGS. 2 and 3). A cooling air outlet 26 is provided at the uppermost inclined position 54 a of the inner wall upper surface 54, and a suction cooling fan 30 is provided in the vicinity of the cooling air outlet 26. Instead of the cooling fan, a cooling fan for blowing air may be disposed in the vicinity of the cooling air inlet 24. Similarly, the inner wall lower surface 56 of the housing 28 is inclined upward in the direction of the arrow L1.

  A mounting plate portion 58 for mounting the assembled battery 22 is provided inside the housing 28. A plurality of openings 60 that open toward the respective assembled batteries 22 are formed in the mounting plate portion 58. The opening 60 is provided in the same number as the number of the assembled batteries 22 arranged along the arrow L direction, for example, five, and extends integrally over the two assembled batteries 22 along the arrow H direction. A passage portion 62 that allows the cooling air introduction port 24 and the plurality of openings 60 to communicate with each other is formed below the mounting plate portion 58.

  The operation of the battery unit 10 configured as described above will be described below.

  As shown in FIG. 5, the assembled batteries 22 are electrically connected to each other in series. When the relay type switch 42 is turned on, power is supplied from the assembled battery 22 to a load including the travel motor 44. The For this reason, the electric vehicle 12 can travel under the drive action of the travel motor 44.

  The remaining capacity of the assembled battery 22 is reduced by supplying power to the traveling motor 44 and the like. On the other hand, the remaining capacity of the assembled battery 22 is recovered by being charged. At that time, each battery 20 constituting the assembled battery 22 tends to vary in remaining capacity. Therefore, the equalization circuit 32 performs a process for equalizing the remaining capacity of each battery 20.

  Specifically, the control unit 52 compares each voltage of each battery 20 to detect the degree of variation, and corresponds to the battery 20 when a battery 20 having a voltage greater than a predetermined value is detected. The switch 50 is turned on. For this reason, in the battery 20 having a large voltage, the electric power is consumed by the electric resistance 48 and equalization is performed. As described above, in the equalization circuit 32, considerable heat is generated when power is consumed by the electric resistance 48.

  In this case, in the present embodiment, an equalization circuit 32 having a relatively high temperature toughness is disposed above the assembled battery 22. For this reason, the assembled battery 22 is hardly affected by the heat generated when the equalization circuit 32 is driven.

  Moreover, inside the housing 28, the cooling air is introduced from the cooling air introduction port 24 positioned below the assembled battery 22, while the cooling air is supplied above the equalization circuit 32. 26 is discharged. Therefore, the cooling air flowing inside the housing 28 can cool the equalizing circuit 32 after cooling the assembled battery 22.

  As a result, it is possible to prevent the influence of heat on the assembled battery 22 due to heat generated during the operation of the equalization circuit 32 as much as possible and to effectively reduce the operation of the cooling fan 30.

  Further, the inner wall upper surface 54 of the housing 28 is inclined upward (in the direction of arrow L1 in FIG. 2) from the cooling air inlet 24 to the cooling air outlet 26, and at the inclined uppermost position 54a of the inner wall upper surface 54. A cooling air outlet 26 is provided. For this reason, the heat generated in the equalization circuit 32 is favorably and smoothly guided to the cooling air outlet 26 along the inclination of the inner wall upper surface 54, and heat transfer to the assembled battery 22 can be suppressed.

  Furthermore, the inner wall lower surface 56 of the housing 28 is similarly inclined upward in the direction of the arrow L1. Therefore, the cooling air introduced from the cooling air introduction port 24 into the passage portion 62 in the housing 28 surely flows to the back side of the passage portion 62 (the front end side in the direction of the arrow L1). The battery pack 22 is sprayed. Thereby, each assembled battery 22 can be effectively cooled.

  The pair of plate-like holding members 38a and 38b are separated from the upper surfaces of the plurality of batteries 20 by a distance S and are extended above the plurality of batteries 20 along the stacking direction by a pair of bridge portions 40a and 40b. They are connected together. An equalizing circuit 32 is mounted on the pair of bridge portions 40a and 40b.

  For this reason, the equalization circuit 32 can be disposed above the assembled battery 22 with a simple and economical configuration, and heat generated in the equalization circuit 32 is favorably transmitted to the assembled battery 22. There is an advantage that it becomes possible to suppress.

DESCRIPTION OF SYMBOLS 10 ... Battery unit 12 ... Electric vehicle 14 ... Underfloor space 16 ... Floor 18 ... Cabin 20 ... Battery 22 ... Battery assembly 24 ... Cooling air inlet 26 ... Cooling air outlet 28 ... Housing 30 ... Cooling fan 32 ... Equalization circuit 38a , 38b ... Holding members 40a, 40b ... Bridge part 44 ... Travel motors 46a-46h ... Wiring 48 ... Electrical resistance 50 ... Switch 52 ... Control part 54 ... Inner wall upper surface 56 ... Inner wall lower surface 58 ... Mounting plate part 60 ... Opening part 62 ... Passage section

Claims (4)

A vehicle battery unit for driving a travel motor provided in a vehicle,
An assembled battery combining a plurality of batteries;
A housing in which the assembled battery is housed and a cooling air introduction port and a cooling air outlet port are provided;
A cooling fan for introducing cooling air into the housing;
An equalization circuit that equalizes the storage amount of the plurality of batteries by discharging the power of the battery having a relatively high storage amount to a resistor in the circuit when there is variation in the storage amount of the plurality of batteries. When,
With
Inside the housing, the equalization circuit is disposed above the assembled battery, at least a part of the cooling air introduction port is located below the assembled battery, and the cooling air outlet port At least a part of the vehicle battery unit is located above the equalization circuit. 2. The vehicle battery unit according to claim 1, wherein the housing has a substantially cubic shape, and an upper surface of an inner wall extending above the equalization circuit is directed from the cooling air inlet to the cooling air outlet. While tilting upward,
The vehicular battery unit, wherein the cooling wind outlet is provided at an uppermost inclined position of the upper surface of the inner wall. The vehicle battery unit according to claim 1 or 2, wherein the assembled battery is formed by laminating the plurality of batteries having a square shape and sandwiched between a pair of plate-shaped holding members from both ends in the stacking direction.
The pair of plate-shaped holding members are integrally connected to each other by a bridge portion that is separated from the upper surfaces of the plurality of batteries and extends along the stacking direction above the plurality of batteries.
The vehicle battery unit, wherein the equalizing circuit is mounted on the bridge portion. The vehicle battery unit according to any one of claims 1 to 3, wherein a mounting plate portion on which the assembled battery is mounted is provided inside the housing.
The mounting plate portion is formed with a plurality of openings that open toward each assembled battery,
A vehicle battery unit, characterized in that a passage portion that connects the cooling air inlet and the plurality of openings is formed below the mounting plate portion.

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