JP2017165334A - Battery temperature regulation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery temperature regulation device which inhibits deterioration of a battery in a more reliable manner.SOLUTION: A battery temperature regulation device includes: an air conditioner 51 which is connected with a battery case 40 and blows temperature controlled air into the battery case 40; a bypass route 54 connecting an exhaust route 71 of an engine 70 with the air conditioner 51; and a temperature regulation control part 57 which causes the air conditioner 51 to operate according to a temperature state of a battery 10 and blows an exhaust gas from the engine 70 into the battery case 40.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a battery temperature control device that adjusts the temperature of a battery (secondary battery) mounted on an electric vehicle including a traveling motor and an engine.

  In recent years, many electric vehicles such as electric vehicles and plug-in hybrid vehicles have been put into practical use. A rechargeable secondary battery (for example, a lithium ion secondary battery) is used as a battery for supplying electric power to a traveling motor mounted on an electric vehicle.

  Such a battery deteriorates as it continues to be used, but the degree of progress of deterioration changes depending on the usage environment. For example, the battery cell terminals constituting the secondary battery and metal parts such as bus bars connecting the terminals are gradually oxidized (deteriorated) due to oxygen in the air. Such oxidation of the components tends to easily proceed when the temperature of the battery including the terminals, bus bars, and the like is high, for example.

  Various devices for adjusting the temperature of a battery by, for example, blowing cooling air with a cooling fan or the like have been proposed (see, for example, Patent Document 1). By adopting such a device and adjusting the temperature of the battery, deterioration of the battery such as oxidation of components can be suppressed.

Japanese Patent Laying-Open No. 2005-063689

  However, there is a possibility that deterioration of the battery cannot be sufficiently suppressed simply by supplying cooling air or the like into the battery. For example, when the battery is in an overcharged state, the temperature of the battery is considerably increased. Therefore, there is a possibility that the temperature rise of the battery cannot be sufficiently suppressed only by supplying cooling air. As a result, there is a risk that the progress of oxidation of the battery cell terminals, bus bars and the like may be accelerated.

  This invention is made | formed in view of such a situation, and it aims at providing the battery temperature control apparatus which can suppress deterioration of a battery more reliably.

  A first aspect of the present invention that solves the above problem is a hybrid vehicle that includes a traveling motor, an engine, and a battery that includes a plurality of battery cells housed in a battery case and supplies electric power to the traveling motor. A battery temperature control device that adjusts the temperature of the battery, the air conditioner being connected to the battery case and sending temperature control air into the battery case, an exhaust path of the engine, and the air conditioner A temperature control unit that operates the air conditioner according to the temperature state of the battery and supplies exhaust gas from the engine into the battery case. It is in the battery temperature control device.

  According to a second aspect of the present invention, in the battery temperature control device according to the first aspect, the battery temperature control device includes a first on-off valve provided in the bypass path, which opens and closes the bypass path, and the temperature control unit A battery temperature control device that opens the first on-off valve and supplies the exhaust gas into the battery case when it is determined that the battery is in an overcharged state based on a state of charge. is there.

  According to a third aspect of the present invention, in the battery temperature control device according to the second aspect, the hybrid vehicle is a plug-in hybrid vehicle capable of charging the battery by an external power source, and the temperature control unit is When the battery is overcharged during charging by an external power source, the first open / close valve is opened, the engine is started, and the exhaust gas is supplied into the battery case. In the device.

  According to a fourth aspect of the present invention, in the battery temperature control apparatus according to the second or third aspect, the introduction path for introducing outside air into the air conditioner, and the second path that is provided in the introduction path and opens and closes the introduction path. An open / close valve is provided, and the temperature control unit is a battery temperature control device that closes the second open / close valve simultaneously with the opening of the first open / close valve.

  According to the battery temperature control apparatus of the present invention, since the exhaust gas from the engine is supplied to the battery, the oxygen concentration in the battery can be kept low. Thereby, the oxidation of metal parts, such as the terminal of a battery cell and a bus bar which comprises a battery, can be suppressed. For example, this is particularly effective in situations where the battery temperature may rise excessively, such as when the battery is overcharged.

It is a schematic perspective view of the electric vehicle which shows the installation state of the battery in which temperature adjustment is performed by the battery temperature control apparatus which concerns on this invention. It is a disassembled perspective view which shows schematic structure of the battery by which temperature adjustment is performed by the battery temperature control apparatus which concerns on this invention. It is a block diagram explaining the schematic structure of the battery temperature control apparatus which concerns on this invention. It is a flowchart which shows an example of the temperature adjustment control of the battery by the battery temperature control apparatus which concerns on this invention.

  Hereinafter, embodiments of a battery temperature control device according to the present invention will be described in detail with reference to the drawings.

  First, an electric vehicle on which the battery temperature control device according to the present invention is mounted is a plug-in hybrid vehicle including a travel motor and an engine. As shown in FIG. 1, a battery pack (battery) 10 is mounted on the bottom (under the floor) of the electric vehicle 1. The battery pack 10 is a high-voltage battery that is composed of, for example, a lithium ion secondary battery and supplies power to a traveling motor (not shown) included in the electric vehicle 1.

  As shown in FIG. 2, the battery pack 10 includes a battery module 30 including a plurality of battery cells 20, and the plurality of battery modules 30 are accommodated in a battery case 40. The battery case 40 includes a battery tray 41 that forms the lower part of the case and a battery cover 42 that forms the upper part of the case.

  As will be described in detail below, the electric vehicle 1 includes a battery temperature adjustment device, and the temperature adjustment air adjusted (cooled or heated) to a predetermined temperature by the air conditioner included in the battery temperature adjustment device is contained in the battery case 40. The air is blown appropriately. Thereby, the temperature of each battery cell 20 in the battery case 40 can be maintained in a predetermined temperature range.

  As shown in FIG. 3, the battery temperature adjustment device 50 according to this embodiment includes an air conditioner 51. The air conditioner 51 adjusts air (outside air) or the like outside the electric vehicle 1 to a predetermined temperature, and supplies the electric power to the traveling motor 60 with the temperature-controlled air adjusted to the predetermined temperature (battery case). 40) Blow in. The air conditioner 51 is similar to an air conditioner (air conditioner) that supplies cold air or warm air into the vehicle interior, but is provided separately from the air conditioner for the vehicle interior.

  An introduction path 52 is connected to the air conditioner 51, and outside air is introduced through the introduction path 52. In addition, one end side of a supply path 53 is connected to the air conditioner 51, and the other end side of the supply path 53 is connected to the battery case 40. In the present embodiment, an inflow port 43 through which temperature-controlled air flows is formed at the front portion (the vehicle front side) of the battery cover 42 constituting the battery case 40 (see FIG. 2), and a supply path is connected to the inflow port 43. The other end side of 53 is connected. Further, a discharge port 44 for discharging the temperature-controlled air to the outside is formed at the rear part (vehicle rear side) of the battery cover 42. The battery case 40, for example, the battery cover 42 is provided with a blower fan 45 for forcibly discharging the temperature-controlled air from the discharge port 44 to the outside.

  Furthermore, a bypass passage (bypass route) 54 branched from an exhaust passage (exhaust passage) 71 of the engine 70 is connected to the air conditioner 51. The exhaust gas of the engine 70 is introduced into the air conditioner 51 as needed through the bypass passage 54. The bypass passage 54 is provided downstream of the exhaust purification catalyst 72 provided in the exhaust passage 71 of the engine 70. Therefore, the exhaust gas purified by the exhaust purification catalyst 72 is supplied to the bypass passage 54.

  The bypass passage 54 is provided with a first opening / closing valve 55 for opening and closing the bypass passage 54. The introduction path 52 is provided with a second on-off valve 56 for opening and closing the introduction path 52. Then, according to the state of the battery cell 20, in the present embodiment, the first on-off valve 55 and the second on-off valve 56 are appropriately opened and closed according to the state of charge of the battery cell 20, and the battery case with exhaust gas as temperature-controlled air as necessary. 40 is supplied.

  Specifically, the battery temperature adjustment device 50 includes a temperature adjustment control unit 57. The temperature adjustment control unit 57 controls the opening / closing operations of the first on-off valve 55 and the second on-off valve 56, and The operation of the air conditioner 51 is controlled, and in this embodiment, the temperature control air supplied to the battery case 40 is adjusted by controlling the blower fan 45.

  The temperature control unit 57 includes an air conditioning control unit 58 that controls the operations of the air conditioner 51 and the blower fan 45, and an opening / closing control unit 59 that controls the operations of the first on-off valve 55 and the second on-off valve 56. I have.

  The air conditioning control means 58 operates the air conditioner 51 and the blower fan 45 in accordance with the temperature state and the charging state (SOC) of the battery cell 20 included in the battery pack 10, and adjusts the temperature-controlled air adjusted to a predetermined temperature to the battery case 40. Blow inside. In other words, the temperature-controlled air flows into the battery case 40 from the inlet 43 of the battery cover 42 and is discharged outside through the outlet 44. Furthermore, in this embodiment, the air-conditioning control means 58 starts the stopped engine 70 as necessary.

  For example, when the temperature of the battery cell 20 is equal to or higher than a predetermined temperature (for example, about 40 ° C.), the air conditioning control unit 58 operates the air conditioner 51 and the blower fan 45 to adjust (for example, cool) to the predetermined temperature. The temperature-controlled air is blown to the battery case 40. Thereafter, when the temperature of each battery cell 20 becomes lower than the predetermined temperature, the operations of the air conditioner 51 and the blower fan 45 are stopped.

  The operations of the air conditioner 51, the blower fan 45, and the engine 70 may be directly controlled by the air conditioning control means 58, or an operation command is sent to the control unit provided in each of the air conditioner 51, the blower fan 45, and the engine 70. And the operation of the air conditioner 51, the blower fan 45, and the engine 70 may be controlled by each control unit. Moreover, the detection method of the temperature of a battery cell 20 or a charge condition (SOC) is not specifically limited, What is necessary is just to detect from various sensors with which the battery pack 10 is provided, for example, measurement results, such as a temperature sensor and a voltage sensor.

  The opening / closing control means 59 appropriately controls the opening / closing states of the first opening / closing valve 55 and the second opening / closing valve 56 in accordance with the state of charge (SOC) of the battery cell 20. Specifically, the opening / closing control means 59 determines whether or not the battery cell 20 is in an overcharged state based on the state of charge (SOC) of the battery cell 20 constituting the battery pack 10. That is, the open / close control means 59 determines whether or not the battery cell 20 is in an overcharged state. In the present embodiment, the open / close control means 59 determines that the battery cell 20 is in an overcharged state when the state of charge (charge rate) is 100% or more, and if it is less than 100%, it is not in an overcharged state. judge.

  When it is determined that the battery cell 20 is in an overcharged state, the opening / closing control means 59 opens the first opening / closing valve 55 and closes the second opening / closing valve 56. On the other hand, when the battery cell 20 is not overcharged, the first on-off valve is closed and the second on-off valve is opened.

  Further, when the battery cell 20 is in an overcharged state and the engine 70 is stopped in this way, the air conditioning control means 58 starts the engine 70.

  Therefore, during normal times when the battery cell 20 is not in an overcharged state, outside air (air outside the vehicle) is introduced into the air conditioner 51 through the introduction path 52, and exhaust gas is not introduced into the air conditioner 51. That is, the air conditioner 51 supplies the temperature-controlled air in which the temperature of the introduced outside air is adjusted into the battery case 40. On the other hand, if the battery cell 20 is overcharged due to some abnormality or the like, the exhaust gas is introduced into the air conditioner 51 through the bypass passage 54 and the outside air is not introduced. That is, the air conditioner 51 adjusts the temperature of the introduced exhaust gas and supplies the exhaust gas to the battery case 40 as temperature-controlled air. The exhaust gas discharged by the combustion of the engine 70 has a lower oxygen concentration than the outside air (atmosphere). Therefore, when the battery cell 20 is in an overcharged state, the air conditioner 51 supplies the exhaust gas having a lower oxygen concentration than the normal time to the battery case 40 as temperature-controlled air.

  Thus, by supplying temperature-controlled air (outside air, exhaust gas) to the battery case 40 and appropriately adjusting the temperature of the battery pack 10 (battery cell 20), it is possible to suppress the deterioration of the characteristics of the battery cell 20. Furthermore, it is possible to suppress deterioration (oxidation) of metal parts constituting the battery pack 10, for example, terminals of the battery cells 20 and bus bars connecting the terminals.

  For example, even when the battery cell 20 is in an overcharged state, deterioration (oxidation) of the metal parts constituting the battery pack 10 can be effectively suppressed. When the battery cell 20 is in an overcharged state, the temperature of the battery cell 20 is likely to rise excessively, and accordingly, deterioration (oxidation) of the metal parts constituting the battery pack 10 is likely to proceed. However, when the battery cell 20 is in an overcharged state, deterioration (oxidation) of metal parts of the battery pack 10 is caused by supplying temperature-controlled air (exhaust gas) having a lower oxygen concentration than normal to the battery case 40. ) Can be more reliably suppressed.

  Further, in the present embodiment, since the engine 70 is forcibly started as necessary during charging of the battery pack 10 by the external power source, the deterioration (oxidation) of the metal parts of the battery pack 10 is further effectively performed. Can be suppressed.

  Next, an example of the temperature control of the battery according to the present embodiment will be described based on the flowchart of FIG.

  When the battery temperature control device 50 is activated, as shown in FIG. 4, first, in step S1, the battery pack 10 (battery cell 20) is overloaded based on the state of charge (SOC) of the battery pack 10 (battery cell 20). It is determined whether or not the battery is charged. As described above, it is determined whether or not the state of charge (SOC) of the battery pack 10 (battery cell 20) is equal to or greater than a preset threshold value (100%).

  Note that the battery temperature control device 50 according to the present embodiment is activated when the ignition switch of the electric vehicle 1 is turned on, and an external power source such as a household power source is connected to the battery pack 10 even when the ignition switch is off. The battery pack 10 is also activated when the battery pack 10 is being charged.

  If it is determined in step S1 that the battery pack 10 is in an overcharged state (step S1: Yes), it is determined in step S2 whether the engine 70 is operating. If the engine 70 is operating in step S2 (step S2: Yes), valve switching, that is, the open / close state of the first on-off valve 55 and the second on-off valve 56 is controlled (step S3). Specifically, the first on-off valve 55 is opened and the second on-off valve 56 is closed. As a result, the exhaust gas from the engine 70 is introduced into the air conditioner 51 through the bypass passage 54 without introducing outside air through the introduction passage 52.

  Thereafter, the air conditioner 51 is operated in step S4, and the blower fan 45 is operated in step S5. That is, the exhaust gas introduced into the air conditioner 51 through the bypass passage 54 is adjusted (cooled) to a predetermined temperature, and flows into the battery case 40 from the inlet 43 as a temperature-controlled air having a lower oxygen concentration than normal. The battery case 40 is discharged from the discharge port 44 to the outside. Thereby, a series of control is completed.

  If the engine 70 is stopped in step S2 (step S2: No), the process proceeds to step S6 to forcibly start the engine 70. For example, when the battery pack 10 is being charged by the external power supply with the engine 70 stopped, the engine 70 is forcibly started. Thereafter, the process proceeds to step S3.

  When the battery pack 10 is in an overcharged state in step S1, there is a high possibility that the temperature of the battery pack 10 has increased, and there is a possibility that the temperature will rise excessively. For this reason, the temperature-controlled air is blown without determining the temperature of the battery pack 10.

  On the other hand, when the battery pack 10 is not in an overcharged state in step S1 (step S1: No), the process proceeds to step S7, and for example, it is determined whether or not the temperature of the battery pack 10 is equal to or higher than a predetermined temperature. At the time of this determination, the first on-off valve 55 is in a closed state and the second on-off valve 56 is in an open state.

  If the temperature of the battery pack 10 is lower than the predetermined temperature (step S7: No), since cooling of the battery pack 10 is unnecessary, a series of control is terminated without supplying the temperature-controlled air into the battery case 40. . On the other hand, if the temperature of the battery pack 10 is equal to or higher than the predetermined temperature (step S7: Yes), the process proceeds to step S4, and the temperature-controlled air whose outside air is adjusted to the predetermined temperature is supplied into the battery case 40. Thereby, the temperature of the battery pack 10 can be adjusted appropriately.

  Note that the air conditioner 51 and the blower fan 45 do not necessarily have to be operated during normal times when the battery pack 10 is not overcharged. For example, when the outside air temperature is low, the outside air may be supplied to the battery case 40 as the temperature-controlled air without operating the air conditioner 51 or the like. Even in this way, it is possible to adjust the temperature of the battery pack 10 appropriately.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. The present invention can be modified as appropriate without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the case where the battery pack is cooled mainly by the temperature-controlled air has been described. Of course, the present invention can also be applied to the case where the battery pack is heated by the temperature-controlled air.

  Further, in the above-described embodiment, the temperature of the exhaust gas is adjusted only when the battery pack is in an overcharged state, and is supplied into the battery case as a temperature-controlled air. However, the exhaust gas is discharged regardless of the charged state of the battery pack. May be supplied to the battery case as temperature-controlled air.

  In the above-described embodiment, the open / close state of the first on-off valve and the second on-off valve is switched so that either the outside air or the exhaust gas is introduced into the air conditioner. You may make it introduce | transduce into an air-conditioning apparatus by a predetermined | prescribed ratio, and may supply the temperature control air which mixed external air and waste gas in a battery case.

1 Electric vehicle (hybrid vehicle)
10 Battery pack (battery)
DESCRIPTION OF SYMBOLS 20 Battery cell 30 Battery module 40 Battery case 41 Battery tray 42 Battery cover 43 Inflow port 44 Outlet port 45 Blower fan 50 Battery temperature control apparatus 51 Air conditioning apparatus 52 Introduction path 53 Supply path 54 Bypass path (bypass path)
55 First Open / Close Valve 56 Second Open / Close Valve 57 Temperature Control Control Unit 58 Air Conditioning Control Unit 59 Open / Close Control Unit 60 Traveling Motor 70 Engine 71 Exhaust Passage (Exhaust Route)
72 Exhaust gas purification catalyst

Claims (4)

A battery temperature control that adjusts the temperature of the battery mounted on a hybrid vehicle including a travel motor, an engine, and a battery that includes a plurality of battery cells housed in a battery case and supplies power to the travel motor. A device,
An air conditioner that is connected to the battery case and blows temperature-controlled air into the battery case;
A bypass path connecting the exhaust path of the engine and the air conditioner,
A battery temperature control device comprising: a temperature control unit that operates the air conditioner according to a temperature state of the battery and supplies exhaust gas from the engine into the battery case. The battery temperature control device according to claim 1,
A first on-off valve provided in the bypass path for opening and closing the bypass path;
The temperature control unit is
When it is determined that the battery is overcharged based on the state of charge of the battery, the first open / close valve is opened, and the exhaust gas is blown into the battery case. Preparation device. The battery temperature control apparatus according to claim 2,
The hybrid vehicle is a plug-in hybrid vehicle capable of charging the battery with an external power source,
The temperature control unit is
When the battery is overcharged during charging by the external power source, the first on-off valve is opened, the engine is started, and the exhaust gas is blown into the battery case. Preparation device. In the battery temperature control device according to claim 2 or 3,
An introduction path for introducing outside air into the air conditioner;
A second opening / closing valve provided in the introduction path for opening and closing the introduction path;
The temperature control unit is
When opening the first on-off valve, the second on-off valve is closed simultaneously with the opening of the first on-off valve.

Images