JP2022135796A - battery cooling system - Google Patents

Abstract

To provide a battery cooling system capable of preventing dielectric breakdown of a cooling pipe even when connecting a cooler and the cooling pipe.SOLUTION: A battery cooling system includes a cooler 42 that is formed using a conductive member that can be electrically connected to a battery module and that has a flow path in which a coolant circulates, a cooling pipe 5 that supplies coolant to the cooler 42, a connector portion 51 that is formed using an insulating member and connects the cooling pipe 5 and the cooler 42, and a ground wire 52 electrically connected to the position of the cooling pipe 5 separated by a predetermined distance D1 from the connection point where the connector portion 51 is connected to the cooler 42.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a battery cooling device.

Patent Document 1 discloses that when a liquid flows through a flow path, friction between flow path walls causes an insulating portion such as a resin diaphragm valve used in a control valve or a control valve to be electrically charged, resulting in dielectric breakdown. Preventive techniques are described. In this technique, a conductive member is placed in the vicinity of the abdomen of the diaphragm so as to pass through the liquid channel on the side of the liquid channel, thereby contacting the liquid, and grounding through the body main body in which the conductive member and the channel are formed. By electrically connecting to the diaphragm, the insulating part such as the diaphragm is prevented from being charged.

JP 2007-78019 A

In recent years, in order to reduce the size of a lithium ion battery, a structure has been studied in which a cooler for cooling the lithium ion battery also functions as a current collector. In the structure where the cooler also functions as a current collector, a part of the cooler through which the coolant flows becomes a high-voltage high-voltage section, and in order to ensure safety, it is separated from the cooler via an insulating member. , and the cooling pipe functioning as an insulating part other than the high-voltage part.

However, even with the technology disclosed in Patent Document 1, which prevents the insulating member from being electrically charged, the cooling pipe is electrically charged due to friction when the coolant flows through the cooling pipe. The voltage may be exceeded and the insulation of the cooling pipes may be destroyed, and if the cooling pipes are in contact with high voltage parts, they may be short-circuited through ground.

The present disclosure has been made in view of the above, and is a battery cooling device capable of preventing dielectric breakdown of the cooling pipe even when the cooler and the cooling pipe are connected. intended to provide

A battery cooling device according to the present disclosure is a battery cooling device having a battery module in which a plurality of battery cells are stacked, is formed using a conductive member that can be electrically connected to the battery module, and has a coolant inside. A cooler having a circulating flow path, a cooling pipe for supplying the coolant to the cooler, a connector portion formed using an insulating member and connecting the cooling pipe and the cooler, and the connector portion a ground wire electrically connected to a position of the cooling pipe spaced apart by a predetermined distance from a connection point connected to the cooler.

According to the present disclosure, the cooler and the cooling pipe are connected via the connector, and the connector is electrically connected to the cooling pipe at a predetermined distance from the connection point where the connector connects to the cooler. Since the ground wire is provided, it is possible to prevent dielectric breakdown of the cooling pipe even when the cooler and the cooling pipe are connected.

FIG. 1 is a schematic diagram showing a schematic configuration of a vehicle equipped with a battery according to Embodiment 1. FIG. FIG. 2 is a perspective view showing a schematic configuration of the battery. FIG. 3 is a side view of the essential parts of the cooling pipes and the cooler as seen from the arrow A in FIG. FIG. 4 is a side view of essential parts of cooling pipes and coolers according to the second embodiment. FIG. 5 is a side view of a cooling pipe and a main part of a cooler according to Embodiment 3. FIG.

Hereinafter, a battery cooling device according to an embodiment of the present disclosure will be described with reference to the drawings. It should be noted that the present disclosure is not limited by the following embodiments. Also, the same parts are denoted by the same reference numerals in the following description.

(Embodiment 1)
[Schematic configuration of vehicle]
FIG. 1 is a schematic diagram showing a schematic configuration of a vehicle equipped with a battery according to Embodiment 1. FIG. A vehicle 1 shown in FIG. 1 is assumed to be an electric vehicle (EV) or a plug-in hybrid vehicle (PHV) using a motor or the like as a power source.

A vehicle 1 includes a motor 2, a power control unit 3 (hereinafter referred to as "PCU 3"), a battery 4, a cooling pipe 5, an electric pump 6, a heat exchanger 7, and an ECU (Electronic Control Unit) 8. , provided.

The motor 2 outputs power for running using the electric power of the battery 4 . Motor 2 is electrically connected to battery 4 via PCU 3 . In the vehicle 1, power output from the motor 2 is transmitted to drive wheels via a power transmission device.

The PCU 3 drives and controls the motor 2 . The PCU 3 includes at least an inverter that drives the motor 2, a boost converter, and a DC/DC converter. For example, in the PCU 3, the inverter converts the DC power of the battery 4 into AC power and supplies the motor 2 with the AC power.

A battery 4 stores power to be supplied to the motor 2 . Specifically, the battery 4 is a power storage device that can be charged with power supplied from an external power supply. The battery 4 is electrically connected to a charging plug of an external charging facility via a charging port (not shown) provided in the vehicle 1, and charges power supplied from the charging facility. The battery 4 is configured using a battery module in which a plurality of planar cells are vertically stacked and a cooler that cools the battery module. A detailed configuration of the battery 4 will be described later.

The cooling pipe 5 has the battery 4 , the electric pump 6 and the heat exchanger 7 connected on the flow path, and the coolant for cooling the battery 4 circulates. Here, any one of air, water, mineral oil, synthetic oil, silicon oil, fluorine oil, insulating refrigerant (for example, CFC substitute refrigerant such as R134a), and insulating oil is used as the refrigerant. Embodiment 1 describes a case where water is used as a coolant. Also, the cooling pipe 5 is configured using a non-conductive material or the like. Specifically, the cooling pipe 5 is configured using rubber, resin, or the like.

The electric pump 6 circulates the refrigerant in the cooling pipe 5 under the control of the ECU 8 . Specifically, the electric pump 6 sucks the refrigerant stored in the reserve tank and discharges the refrigerant toward the cooling pipe 5 from the discharge port. The refrigerant discharged by the electric pump 6 circulates through the cooling pipe 5 , the battery 4 and the heat exchanger 7 due to the discharge pressure of the electric pump 6 .

Under the control of the ECU 8 , the heat exchanger 7 exchanges heat with the refrigerant circulating in the cooling pipe 5 to radiate heat from the refrigerant. The heat exchanger 7 is configured using, for example, a radiator and an electric fan.

The ECU 8 controls driving of the electric pump 6 and the heat exchanger 7 . The ECU 8 is configured using a memory and a processor having hardware such as a CPU (Central Processing Unit).

[Detailed configuration of the battery]
Next, the detailed configuration of the battery 4 will be described. FIG. 2 is a perspective view showing a schematic configuration of the battery.

As shown in FIG. 2, the battery 4 includes a battery module 41 in which a plurality of battery cells 410 are stacked, and a planar cooler 42 connected to both upper and lower surfaces of the battery module 41 to cool the battery module 41. Prepare. Specifically, as shown in FIG. 2, the battery 4 is configured by stacking a cooler 42, a battery module 41, and a cooler 42 in this order. Although the battery 4 shown in FIG. 2 has one battery module 41, the number of battery modules 41 to be stacked can be changed as appropriate if the upper and lower surfaces of the battery module 41 can be sandwiched between the coolers 42 and stacked. can do. Furthermore, the number of coolers 42 is sufficient as long as the battery modules 41 can be sandwiched and stacked, and can be appropriately changed according to the number of stacked battery modules 41 .

The battery module 41 is configured by stacking a plurality of flat battery cells 410 along the vertical direction. Battery cell 410 is configured using one of a bipolar structure and a monopolar structure. Furthermore, in FIG. 2, the battery 4 is configured by stacking four layers of the battery cells 410, but the number of stacked battery cells 410 can be changed as appropriate.

The cooler 42 is connected to the cooling pipe 5 and is connected to an inlet portion 421 to which the coolant Wa is supplied from the electric pump 6 via the cooling pipe 5 , and is also connected to the cooling pipe 5 so that the coolant Wa flows out to the cooling pipe 5 . and an outlet portion 422 . The cooler 42 cools the battery module 41 by circulating the coolant Wa in a channel formed inside. The cooler 42 is constructed using a conductive member such as aluminum. Furthermore, the coolers 42 positioned above and below the battery 4 function as electrodes (collector plates) of the battery 4 by being electrically connected to the battery module 41 . As a result, it is not necessary to provide a terminal for extracting electric power from the battery 4, so the size of the battery 4 can be reduced. In Embodiment 1, cooling pipe 5 , electric pump 6 , heat exchanger 7 and cooler 42 function as a cooling device for battery 4 .

[Connection between cooling pipe and cooler]
Next, a method for connecting the cooling pipe 5 and the cooler 42 will be described in detail. FIG. 3 is a side view of essential parts of the cooling pipe 5 and the cooler 42 as seen from the arrow A in FIG. Although the connection between the cooling pipe 5 and the inlet portion 421 of the cooler 42 will be described in detail in FIG. 3, the cooling pipe 5 and the outlet portion 422 of the cooler 42 are also connected by the same method.

As shown in FIG. 3 , the inlet portion 421 of the cooler 42 is connected to the cooling pipe 5 via the connector portion 51 . The connector portion 51 is made of an insulating member such as rubber or resin, and has a tubular shape. Furthermore, a ground wire 52 is electrically connected to the cooling pipe 5 at a position a predetermined distance D1 away from an end portion 421a on the connection side where the connector portion 51 is connected to the inlet portion 421. . Note that the ground is electrically connected to the vehicle 1 .

Here, the predetermined distance D1 means that when the voltage of the battery 4 is 400 V and the minimum clearance distance is 0.8 mm and the minimum creepage distance is 5.6 mm under the environment of pollution degree 3 according to JISC0664, It is a position up to 5.6 mm toward the cooling pipe 5 from the connection side (end 421a side of the inlet portion 421). That is, the ground wire 52 is electrically connected to a position where the combined distance of the connector portion 51 and the cooling pipe 5 is 5.6 mm or more away from the cooler 42 (inlet portion 421) functioning as a high pressure portion.

As a result, the battery 4 can cut off the continuity between the battery module 41 and the cooler 42, and even if the cooling pipe 5 is charged, the cooling pipe 5, which functions as an insulating part, can cause dielectric breakdown. can be prevented.

In the first embodiment described above, the cooling pipe 5 and the cooler 42 are connected via the connector portion 51, and the cooling pipe 5 is separated from the connection point where the connector portion 51 connects to the cooler 42 by a predetermined distance. Since the ground wire 52 electrically connected to the position is provided, the dielectric breakdown of the cooling pipe 5 can be prevented.

In Embodiment 1, the connector portion 51 is provided between the inlet portion 421 of the cooler 42 and the cooling pipe 5 , but the connector portion 51 is provided between the outlet portion 422 of the cooler 42 and the cooling pipe 5 . may be provided, and the ground wire 52 may be electrically connected to a position separated by a predetermined distance.

In addition, in Embodiment 1, the cooling pipe 5 is formed of a non-conductive member, but is not limited to this. The inner wall of the path may be provided with an insulation coating, such as an insulation treatment or an alumite treatment, so that it functions as an insulation portion.

(Embodiment 2)
Next, Embodiment 2 will be described. FIG. 4 is a side view of essential parts of cooling pipes and coolers according to the second embodiment.

As shown in FIG. 4, a cooling pipe 5A and a connector portion 51A are provided instead of the cooling pipe 5 and the connector portion 51 of the first embodiment.

5 A of cooling pipes are comprised using an electroconductive member. 5 A of cooling pipes are comprised using aluminum, an aluminum alloy, etc., for example. Furthermore, a ground wire 52 is electrically connected to the cooling pipe 5A.

The connector portion 51A has a predetermined length D2 in the channel direction (longitudinal direction) in which the coolant Wa flows. Specifically, the length D2 of the connector portion 51A is 5.6 mm when the minimum spatial distance is 0.8 mm and the minimum creepage distance is 5.6 mm under the environment of pollution degree 3 according to JISC0664. The connector portion 51A is made of an insulating member such as rubber or resin, and has a tubular shape.

According to the second embodiment described above, by connecting the cooler 42 and the cooling pipe 5A via the connector portion 51A having the predetermined length D2, the location of use of the insulator where there is a possibility of dielectric breakdown is eliminated. can be reduced, and the area connected to the connector portion 51A functioning as an insulating material can be increased. can be done.

(Embodiment 3)
Next, Embodiment 3 will be described. FIG. 5 is a side view of a cooling pipe and a main part of a cooler according to Embodiment 3. FIG.

As shown in FIG. 5, cooling pipe 5 is electrically connected to SW1, capacitor C1, SW2, and power fuse R1 in addition to the configuration of the first embodiment.

Cooling pipe 5 is electrically connected to ground via SW1 and capacitor C1. As the capacitance of the capacitor C1, a capacitance that does not cause dielectric breakdown due to charging is used. Furthermore, in the cooling pipe 5, a power fuse R1 (resistor) is electrically connected to ground in parallel with the capacitor C1 via a switch SW2. The capacity of the power fuse R1 is a capacity that is not cut when the capacitor C1 is discharged and is cut only when short-circuited. SW1 and SW2 perform ON/OFF operation under the control of ECU8. As a result, the charge accumulated in the capacitor C1 is periodically discharged via the power fuse R1.

According to the third embodiment described above, by electrically connecting the ground to the cooling pipe 5 via at least one of the capacitor C1 and the power fuse R1, the ground position of the cooler 42 functions as a high voltage section. Even if the distance required for insulation from the cooling pipe 5 cannot be secured, it is possible to prevent dielectric breakdown from occurring in the cooling pipe 5.

Furthermore, according to Embodiment 3, the ECU 8 cuts off the electrical connection from the cooling pipe 5 via the switch SW1 when discharging from the capacitor C1, so that the electric charge accumulated in the cooler 42 can be discharged periodically. .

(Other embodiments)
Further effects and modifications can be easily derived by those skilled in the art. The broader aspects of the invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various changes may be made without departing from the spirit or scope of the general inventive concept defined by the appended claims and equivalents thereof.

1 vehicle 2 motor 3 PCU
4 battery 5, 5A cooling pipe 6 electric pump 7 heat exchanger 8 ECU
41 battery module 42 cooler 51, 51A connector portion 52 ground wire 410 battery cell 421 inlet portion 421a end portion 422 outlet portion C1 capacitor R1 power fuse SW1, SW2 switch Wa refrigerant

Claims (1)

A battery cooling device having a battery module in which a plurality of battery cells are stacked,
a cooler formed using a conductive member that can be electrically connected to the battery module and having a flow path in which a coolant circulates;
a cooling pipe that supplies the coolant to the cooler;
a connector portion formed using an insulating member and connecting the cooling pipe and the cooler;
a ground wire electrically connected to a position of the cooling pipe at a predetermined distance from a connecting portion where the connector portion is connected to the cooler;
comprising
battery cooling system.

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