JP2013173469A - Cooling structure of battery case of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling structure of a battery case of a vehicle, advantageous when securing a cooling function even in a state of stopping introduction of air to the inside of the battery case.SOLUTION: When an electric fan 28 stops, a flow of air inside of a battery case 10 stops. Then, the air inside of the battery case 10 is warmed by remaining heat of a battery module 12 and an electric part 14. The warmed air rises by a natural convection, and therefore, flows to a duct part 2006 via a discharge port 2002 of an exhaust duct 20 from the inside of the battery case 10, and is exhausted to a space under a floorboard 8 from an opening part 30. The exhausted air moves along an under surface of the floorboard 8, and is gradually diffused by rising in a trunk room by passing through a clearance between an edge part of the floorboard 8 and a vehicle body. The flow of the air is generated inside the battery case 10 and inside the exhaust duct 20, and the flow of the air flowing inside the battery case 10 is also generated.

Description

  The present invention relates to a cooling structure for a battery case of a vehicle.

In an electric vehicle such as an electric vehicle or a hybrid vehicle using a motor as a drive source, a battery module that supplies power to the motor is housed in a battery case.
Since the battery module generates heat as it is charged and discharged, a structure for cooling the inside of the battery case is provided.
As such a cooling structure for the battery case, air outside the battery case is introduced into the battery case using an electric fan, and the air inside the battery case is exhausted outside the battery case through the exhaust duct. The thing is proposed (refer patent document 1).

Japanese Patent No. 3772549

However, since the electric fan stops when the electric system of the vehicle is stopped after traveling, the forced air flow of air into the battery case stops. The temperature of the air inside the battery case rises.
The present invention has been made in view of the above circumstances, and is a cooling structure for a vehicle battery case that is advantageous in suppressing an increase in the temperature of air inside the battery case even when the electric system of the vehicle is stopped. The purpose is to provide.

  In order to achieve the above object, the present invention accommodates a battery for supplying electric power to a motor for driving a vehicle, and has a battery case attached to the vehicle body and a suction port communicating with the inside of the battery case at one end. An intake duct having an exhaust port communicating with the inside of the battery case at the end, an exhaust duct having an exhaust port at the other end positioned outside the battery case, and air outside the battery case A cooling structure for a battery case of a vehicle, comprising air blowing means for introducing air into the battery case through a duct and exhausting air inside the battery case from the exhaust port through the exhaust duct. The air inside the battery case is outside the exhaust duct when the air blowing means is stopped at the upper surface of the exhaust duct or a location near the upper surface. Characterized in that a different opening and the outflow can the exhaust port and.

According to the first aspect of the present invention, when the air blowing means is stopped, the air inside the battery case flows through the exhaust duct by the natural convection through the exhaust duct to the outside of the exhaust duct. For this reason, it is advantageous in suppressing an increase in the temperature of the air inside the battery case.
According to the second aspect of the present invention, since the opening is provided at the upper surface of the duct portion or at a position near the upper surface, the warmed air inside the battery case easily flows out of the exhaust duct through the opening. Thus, it is more advantageous in suppressing an increase in the temperature of the air inside the battery case.
According to the invention described in claim 3, since the bent portion bent downward is formed on the downstream side of the flow of air flowing toward the exhaust port rather than the opening portion, the air staying in the bent portion is formed. Rises toward the opening and is exhausted out of the exhaust duct from the opening. Therefore, it is advantageous in suppressing an increase in the temperature of the duct portion downstream of the opening.
According to the fourth aspect of the present invention, when the ventilator is releasing the air in the vehicle interior to the outside of the vehicle interior, the air exhausted from the exhaust port is quickly exhausted outside the vehicle interior via the ventilator. This is advantageous in suppressing the temperature rise.
According to the invention described in claim 5, after the air exhausted from the opening moves along the lower surface of the floor board, it gradually enters the space of the trunk room via the gap between the edge of the floor board and the vehicle body. Since it is diffused, it is possible to prevent the trunk room from being heated locally.
According to the sixth aspect of the invention, it is advantageous to suppress the influence of the residual heat of the electric component on the battery module or the influence of the residual heat of the battery module on the electric component.

It is a perspective view which shows the rear part of a vehicle provided with the cooling structure of the battery case 10 of the vehicle of this Embodiment. It is AA sectional view taken on the line of FIG. 3 is an explanatory diagram showing the flow of air inside the battery case 10. FIG. 4 is an explanatory diagram showing the air flow of the cooling structure of the battery case 10 when the electric fan 28 is operating. FIG. FIG. 6 is an explanatory diagram showing an air flow in a cooling structure of the battery case 10 when the electric fan 28 is stopped.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 3, the cooling structure for the vehicle battery case of the present embodiment is provided in an electric vehicle 2 such as an electric vehicle or a hybrid vehicle using a motor as a drive source.
A battery module 12 and an electrical component 14 are accommodated in the battery case 10.
The cooling structure 16 for the battery case 10 includes the battery case 10, the air blowing means 18, and the exhaust duct 20.

The battery case 10 is housed in a housing recess 6 formed in the floor panel 4 at the rear of the vehicle body, and is attached to the floor panel 4.
The portions of the floor panel 4 on both sides in the vehicle width direction of the housing recess 6 are placement portions 4A on which the floor board 8 (FIG. 4) is placed. When the floor board 8 is placed on the placement portion 4A, the housing recess 6 is covered, and the placed floor board 8 constitutes the floor surface of the trunk room.
In addition, the code | symbol 5 in a figure shows the wheel house of a rear wheel.

As shown in FIG. 4, the battery case 10 includes a tray 22 and a cover 24.
The tray 22 has a rectangular plate-like bottom wall, a peripheral wall standing up from the periphery of the bottom wall, and a tray-side flange extending over the entire periphery of the peripheral wall at the top of the peripheral wall. An open storage space is provided above the storage space.
The cover 24 has an upper wall of a rectangular plate shape, a peripheral wall suspended from the periphery of the upper wall, and a cover-side flange extending over the entire periphery of the peripheral wall at the lower part of the peripheral wall.
The cover 24 closes the accommodation space by overlapping the cover side flange with the tray side flange.

As shown in FIG. 3, the battery module 12 includes a plurality of battery cells (batteries referred to in the present invention) connected in series. In FIG. 3, in order to simplify the drawing, a plurality of battery cells are drawn with one rectangular outline.
The electrical component 14 is electrically connected to the battery module 12 and causes the battery module 12 to function.
The battery module 12 generates heat as it is charged / discharged.
In the present embodiment, the electrical component 14 includes an inverter and a DCDC converter.
The inverter converts the DC power of the battery module 12 into three-phase AC power and supplies it to the motor.
The DCDC converter steps down the voltage of the DC power of the battery module 12 and supplies the stepped down DC power to, for example, a battery for electrical equipment or auxiliary equipment.
These inverters and the DCDC converter generate heat when operating with power supplied from the battery module 12.

The battery module 12 and the electrical component 14 are accommodated in the battery case 10, and the battery module 12 is disposed below the electrical component 14.
By providing a partition wall 1002 between the battery module 12 and the electrical component 14, a first flow path L 1 through which air can flow is defined around the battery module 12, and air flows on the lower surface side of the electrical component 14. A second flow path L2 capable of circulation is defined. The first flow path L1 and the second flow path L2 communicate with each other through an opening (not shown) formed in the partition wall 1002.

As shown in FIGS. 1 and 4, the air blowing means 18 introduces air outside the battery case 10 into the battery case 10 and exhausts air inside the battery case 10 to an exhaust port 20 of an exhaust duct 20 described later. Is exhausted from.
In the present embodiment, the air blowing means 18 includes an intake duct 26 and an electric fan 28.
The intake duct 26 has an intake port 2602 outside the battery case 10, and has an intake port 2604 communicating with the inside of the battery case 10 at one end different from the end portion having the intake port 2602. The outside air is guided to the inside of the battery case 10. That is, the intake port 2602 is an intake port that sucks air outside the battery case 10 toward the intake duct 26, and the intake port 2604 is an intake port that sucks air from the intake duct 26 into the battery case 10. The intake port 2602 and the intake port 2604 are different from each other.
In the present embodiment, intake port 2602 is located near the side of the rear seat.
The electric fan 28 is interposed in the middle of the extending direction of the intake duct 26.
When the electric fan 28 operates, the air sucked from the air inlet 2602 is guided into the battery case 10 through the air intake duct 26.

The exhaust duct 20 has an exhaust port 2004 outside the battery case 10 and guides the air inside the battery case 10 to the outside of the battery case 10.
As shown in FIG. 4, the exhaust duct 20 is disposed along the floor board 8 below the floor board 8.
As shown in FIG. 1, the exhaust port 2004 is disposed in the vicinity of the ventilator 9 that allows the air in the passenger compartment to escape outside the passenger compartment.
As shown in FIG. 2, the exhaust duct 20 has a discharge port 2002 communicating with the inside of the battery case 10, and a duct portion 2006 extending from the discharge port 2002 without being displaced downward to reach the outside of the battery case 10. doing. The discharge port 2002 is a discharge port that discharges air inside the battery case 10 toward the exhaust duct 20, and is different from the exhaust port 2004 that exhausts air from the exhaust duct 20 to the outside of the exhaust duct 20. It is.
As shown in FIGS. 1 and 5, air flows from the inside of the battery case 10 to the exhaust port 2004 when the blower 18 is driven, on the upper surface of the exhaust duct 20 located outside the battery case 10 or near the upper surface. An opening 30 is provided which is different from the exhaust port 2004 through which the air inside the battery case 10 can flow out of the exhaust duct 20 when the blower 18 is stopped.
The opening 30 is provided at the upper surface of the duct portion 2006 or at a location near the upper surface.
A bent portion 32 bent downward is formed on the downstream side of the flow of air flowing toward the exhaust port 2004 with respect to the duct portion 2006 provided with the opening 30.

Next, the operation of the cooling structure 16 of the battery case 10 of the vehicle will be described.
First, the case where the electric fan 28 operates will be described.
When the electric fan 28 operates, the air sucked from the intake port 2602 is guided into the battery case 10 through the intake duct 26.
As shown in FIG. 3, the air introduced into the battery case 10 is guided to the first flow path L1, and after cooling the battery module 12 by passing through the surface of the battery cell that has generated heat due to charge and discharge, It is guided to the second flow path L2 through the opening of the partition wall 1002.
The air guided to the second flow path L2 passes through the lower surface of the electrical component 14 to cool the electrical component 14, and then passes through the duct portion 2006 from the exhaust port 2002 of the exhaust duct 20 as shown in FIG. It passes through the exhaust port 2004 and is exhausted to the space below the floor board 8.
At this time, the opening 30 enables air to flow from the inside of the battery case 10 to the exhaust port 2004. That is, the opening 30 does not hinder the air flow toward the exhaust port 2004 in the exhaust duct 20.

The air exhausted from the exhaust port 2004 to the space below the floor board 8 rises by natural convection, moves along the lower surface of the floor board 8, passes through the gap between the edge of the floor board 8 and the vehicle body, and enters the trunk room. And gradually spread.
In addition, when air conditioning is performed by outside air circulation in which outside air is introduced into the vehicle interior, the ventilator 9 functions to release the air in the vehicle interior to the outside of the vehicle interior. That is, an air flow is formed in which the air in the passenger compartment flows outside the passenger compartment via the ventilator 9.
In the present embodiment, since the exhaust port 2004 is located in the vicinity of the ventilator 9, the air exhausted from the exhaust port 2004 is efficiently exhausted from the ventilator 9 along with the flow of the air to the outside of the vehicle interior. This is advantageous in suppressing the temperature rise.

Next, the case where the electric system of the vehicle is stopped and the electric fan 28 is stopped will be described.
When the electric fan 28 stops, the air flow inside the battery case 10 stops.
Then, the air inside the battery case 10 is warmed by the residual heat of the battery module 12 and the electrical component 14.
Since the warmed air rises due to natural convection, it flows from the inside of the battery case 10 to the duct portion 2006 via the exhaust port 2002 of the exhaust duct 20 and is exhausted from the opening 30 to the space below the floor board 8. This air flow is indicated by arrows A, B and C in FIG.
The exhausted air moves along the lower surface of the floor board 8 and, as indicated by an arrow D, rises into the trunk room through the gap between the edge of the floor board 8 and the vehicle body and is gradually diffused.
Since air flows indicated by arrows A, B, and C are generated in the battery case 10 and the exhaust duct 20, an air flow that flows from the intake port 2602 through the intake duct 26 to the inside of the battery case 10 is also generated. That is, a flow of air that is introduced from the intake port 2602, passes through the intake duct 26, the battery case 10, the duct portion 2006, and is exhausted from the opening 30 is generated.
Therefore, even when the electric fan 28 is stopped, air flows into the battery case 10, which is advantageous in suppressing an increase in the temperature of the air inside the battery case 10.
Since the flow rate of air exhausted from the exhaust port 2004 by natural convection is small, even if the temperature of the floor board 8 is raised by warm air exhausted from the opening 30, it is negligible and placed on the floor board 8. The risk of the package being warmed is negligible.

As described above, according to the present embodiment, when the air blowing means 18 is stopped, the air inside the battery case 10 flows outside the exhaust duct 20 through the opening 30 by natural convection. As a result, an air flow is generated inside the battery case 10, so that it is possible to suppress the remaining heat of the battery module 12 from being stored inside the battery case 10, which is advantageous in suppressing an increase in the temperature of the air inside the battery case 10.
Note that, when the battery module 12 and the electrical component 14 are accommodated in the battery case 10 as in the present embodiment, the influence of the residual heat of the electrical component 14 on the battery module 12 or the battery module 12. This is also advantageous in suppressing the influence of the remaining heat on the electrical component 14.
Further, according to the present embodiment, since the opening 30 is provided at the upper surface of the duct portion 2006 or at a location near the upper surface, the warmed air inside the battery case 10 is exhausted through the opening 30 to the exhaust duct. It becomes easy to flow out of 20, and becomes more advantageous in suppressing the rise in the temperature of the air inside the battery case 10.
Further, according to the present embodiment, the bent portion 32 bent downward is formed on the downstream side of the flow of air flowing toward the exhaust port 2004 rather than the opening portion 30, so that it stays in the bent portion 32. The rising air rises toward the opening 30 and is exhausted from the opening 30 to the outside of the exhaust duct 20. Therefore, it is advantageous in suppressing an increase in the temperature of the duct portion 2006 on the downstream side of the opening 30.
Further, according to the present embodiment, the air exhausted from the opening 30 moves along the lower surface of the floor board 8 and then the space of the trunk room via the gap between the edge of the floor board 8 and the vehicle body. As a result, the trunk room is locally heated.
Further, in the present embodiment, the case where the battery module 12 and the electrical component 14 are accommodated inside the battery case 10 has been described, but the case where only the battery module 12 is accommodated inside the battery case 10 is also described. Of course, the present invention is applicable.

  2 ... Electric vehicle, 4 ... Floor panel, 6 ... Housing recess, 8 ... Floor board, 9 ... Ventilator, 10 ... Battery case, 12 ... Battery module, 14 ... Electrical component, 16 ... Cooling structure of battery case, 18 ... air blowing means, 20 ... exhaust duct, 2002 ... exhaust port, 2004 ... exhaust port, 2006 ... duct part, 22 ... tray, 24 ... cover, 26 ... air intake Duct, 2602... Intake port, 2604... Suction port, 28... Electric fan, 30.

Claims (6)

A battery case that houses a battery that supplies power to a motor that drives the vehicle, and is attached to the vehicle body;
An intake duct having an intake port communicating with the inside of the battery case at one end;
An exhaust duct having an exhaust port communicating with the inside of the battery case at one end, and an exhaust port at the other end located outside the battery case;
And air blowing means for introducing air outside the battery case into the battery case via the intake duct and exhausting air inside the battery case from the exhaust port via the exhaust duct. A cooling structure for a battery case of a vehicle,
An opening different from the exhaust port through which the air inside the battery case can flow out to the outside of the exhaust duct when the air blowing means is stopped is provided at a location near the upper surface or the upper surface of the exhaust duct.
A cooling structure for a battery case of a vehicle. The exhaust duct has a duct portion that extends downward from the discharge port and reaches the exhaust port,
The opening is provided at a location near the upper surface or the upper surface of the duct portion.
The cooling structure for a battery case of a vehicle according to claim 1. The exhaust duct is formed with a bent portion bent downward on the downstream side of the flow of air flowing toward the exhaust port rather than the duct portion.
The cooling structure for the battery case of the vehicle according to claim 2. The exhaust port is disposed in the vicinity of a ventilator that allows the air in the passenger compartment to escape outside the passenger compartment.
The cooling structure for a battery case of a vehicle according to any one of claims 1 to 3. The exhaust duct is disposed along the floor board below the floor board constituting the floor surface of the trunk room.
The cooling structure for a battery case of a vehicle according to any one of claims 1 to 4, wherein: An electrical component electrically connected to the battery is housed inside the battery case,
The cooling structure for a battery case of a vehicle according to any one of claims 1 to 5, wherein:

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