Hybrid vehicles

Abstract

To enable detection of temperature rise of electronic equipment disposed in a battery pack due to radiation heat in an exhaust passage.SOLUTION: A battery pack 50 disposed on the underfloor of a hybrid vehicle 1 includes: a battery stuck 55 where battery cells are laminated; a battery ECU51 and a monitoring unit 52. A temperature sensor 53 fitted to a flue gas passage 94 is disposed at a position between the battery ECU51 and the monitoring unit 52, and an exhaust pipe 21. The temperature sensor 53 is disposed between the battery ECU51 and the monitoring unit 52, and the exhaust pipe 21, and therefore favorably detects the temperature rise of the battery ECU 51 and the monitoring unit 52 due to radiation heat from the exhaust pipe 21.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a hybrid vehicle. [Background Art]

[0002] Japanese Unexamined Patent Application Publication No. 2021-109577 (Patent Document 1) discloses a technique for diagnosing whether there is an abnormality in a cooling device that cools a battery pack mounted on a hybrid vehicle. This Patent Document 1 includes a plurality of temperature sensors that each detect the temperature TB of a respective battery stack. Then, the presence or absence of an abnormality in the cooling device is diagnosed using the temperature TB of the battery stack detected by a temperature sensor that is not affected by radiant heat from an exhaust pipe. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2021-109577 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In addition to battery stacks, electronic devices such as a battery ECU (Electronic Control Unit) and a monitoring unit may be arranged inside a battery pack. Radiant heat from an exhaust pipe (exhaust passage) through which exhaust gas flows can increase the internal temperature of the battery pack, potentially exceeding the guaranteed operating temperature of the electronic devices.

[0005] An object of the present disclosure is to enable detection of a temperature rise of electronic devices arranged in a battery pack caused by radiant heat from an exhaust passage. [Means for Solving the Problem]

[0006] The hybrid vehicle of this disclosure is a hybrid vehicle comprising an internal combustion engine, an exhaust passage through which exhaust gases discharged from the internal combustion engine flow, and a battery pack located under the floor of the vehicle. The battery pack includes a battery stack of stacked battery cells, electronic equipment, and a temperature sensor located between the electronic equipment and the exhaust passage.

[0007] In this configuration, the battery pack may be heated by radiant heat from the exhaust passage, causing the temperature of the electronic device to rise. Since the temperature sensor is positioned between the electronic device and the exhaust passage, it can effectively detect the temperature rise of the electronic device due to radiant heat.

[0008] Preferably, the battery pack further includes a smoke exhaust passage for discharging gases released from the battery cells to the outside of the battery pack, and the temperature sensor may be a temperature sensor provided in the smoke exhaust passage.

[0009] The battery cell is equipped with a safety valve that vents (releases) gas to the outside of the battery cell when the internal pressure rises abnormally due to gas generation, such as in the event of an abnormality. The battery pack has a smoke exhaust passage that discharges the gas released from the battery cell to the outside of the battery pack. The smoke exhaust passage is equipped with a temperature sensor that detects when gas is discharged from the battery cell. With this configuration, the temperature rise of electronic equipment due to radiant heat can be detected using the smoke detection temperature sensor provided in the smoke exhaust path, so there is no need to install a new temperature sensor.

[0010] Preferably, the hybrid vehicle further includes a control device, which may perform high-temperature processing when the temperature detected by the temperature sensor is above a predetermined temperature. In this case, the predetermined temperature may be set lower than the temperature detected by the temperature sensor when gas is released from the battery cell.

[0011] In this configuration, the control device performs high-temperature processing when the temperature detected by the temperature sensor is above a predetermined temperature. High-temperature processing may, for example, involve storing a diagnostic code indicating that the electronic equipment was under high-temperature conditions. When servicing a hybrid vehicle, the service tool can refer to the diagnostic code to determine that the electronic equipment was under high-temperature conditions.

[0012] By setting a predetermined temperature lower than the temperature detected by the temperature sensor when gas is released from the battery cell, it is possible to store as a diagnostic code that the temperature of the electronic device has risen due to radiant heat from the exhaust passage, rather than due to the temperature rise caused by the gas released from the battery cell. [Effects of the Invention]

[0013] According to this disclosure, it is possible to detect the temperature rise of electronic devices placed inside the battery pack due to radiant heat from the exhaust passage. [Brief explanation of the drawing]

[0014] [Figure 1] This diagram schematically shows the overall configuration of the hybrid vehicle according to this embodiment. [Figure 2] This diagram illustrates an example of the arrangement of the engine, exhaust pipe, and battery pack in this embodiment. [Figure 3] This is a cross-sectional view illustrating the configuration of the battery pack. [Figure 4] This flowchart shows an example of battery pack temperature processing performed by the ECU. [Modes for carrying out the invention]

[0015] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0016] Figure 1 is a schematic diagram showing the overall configuration of the hybrid vehicle 1 according to this embodiment. Figure 1 shows that the hybrid vehicle 1 and the charging equipment 5 are electrically connected by a charging cable 3, and the hybrid vehicle 1 and the charging equipment 9 are electrically connected by a charging cable 7.

[0017] Charging equipment 5 is, for example, a standard charger installed in a typical home. Charging equipment 5 outputs AC power supplied from an external power source, the grid power, to the hybrid vehicle 1. Charging equipment 9 is a fast charger that converts AC power from an external power source, the grid power, into DC power and outputs it to the hybrid vehicle 1. When the hybrid vehicle 1 is being externally charged, it is electrically connected to either charging equipment 5 or charging equipment 9 via a charging cable.

[0018] In this embodiment, the hybrid vehicle 1 is a plug-in hybrid vehicle that can be charged externally. However, the hybrid vehicle 1 may also be a hybrid vehicle that does not use external charging. The hybrid vehicle 1 comprises a motor generator 101, a motor generator 102, an engine 103, a power split device 104, drive wheels 105, a power control unit (PCU) 106, an air conditioning unit 107, a system main relay (SMR) 108, a battery pack (energy storage device) 50, charging relays 110 and 120, a power converter 111, inlets 112 and 122, and an electronic control unit (ECU) 116.

[0019] Each of motor generators 101 and 102 is, for example, a three-phase AC rotating electric machine. The motor generator 101 is connected to a crankshaft of an engine 103 via a power split device 104. When starting the engine 103, the motor generator 101 uses electric power from a battery pack 50 to rotate the crankshaft of the engine 103. Further, the motor generator 101 is also capable of generating electric power using the power of the engine 103. AC power generated by the motor generator 101 is converted into DC power by a PCU 106, and the DC power is charged into the battery pack 50. Further, the AC power generated by the motor generator 101 may be supplied to the motor generator 102 in some cases.

[0020] The motor generator 102 rotates a drive shaft using at least one of electric power from the battery pack 50 and electric power generated by the motor generator 101. Further, the motor generator 102 is also capable of generating electric power by regenerative braking. AC power generated by the motor generator 102 is converted into DC power by the PCU 106, and the DC power is charged into the battery pack 50.

[0021] The engine 103 is an internal combustion engine such as a gasoline engine or a diesel engine, and is controlled in accordance with a control signal from a control ECU 116. The engine 103 includes an exhaust system 20 for purposes such as purifying exhaust gas discharged from the engine 103 and reducing exhaust noise. The exhaust system 20 includes an exhaust passage (exhaust pipe) 21, and includes an exhaust purification catalyst 211, a waste heat recovery device 212, a silencer 213, and the like. The waste heat recovery device 212 recovers exhaust heat energy and uses the recovered energy for heating of an air conditioner 107 and the like.

[0022] The power split device 104 is, for example, a planetary gear mechanism, and splits power generated by the engine 103 into power transmitted to drive wheels 105 and power transmitted to the motor generator 101.

[0023] The PCU 106 converts the DC power stored in the battery pack 50 into AC power and supplies it to the motor generators 101 and 102 in response to a control signal from the control ECU 116. The PCU 106 also converts the AC power generated by the motor generators 101 and 102 into DC power and supplies it to the battery pack 50.

[0024] The electric compressor of the air conditioning unit 107 is electrically connected between the PCU 106 and the SMR 108. The air conditioning unit 107 may be an air conditioner that forms a refrigeration cycle using an electric compressor.

[0025] The SMR108 is electrically connected to the power line connecting the PCU106 and the battery pack 50. The SMR108 switches between supplying and cutting off power between the PCU106 and the battery pack 50 in response to a control signal from the control ECU116.

[0026] The battery pack (energy storage device) 50 is a DC power source configured to allow charging and discharging. Details of the battery pack 50 will be described later. The battery pack 50 supplies power to the PCU 106 to generate the driving force of the hybrid vehicle 1. The battery pack 50 also stores the power generated by the motor generator 101.

[0027] The charging relay 110 is electrically connected to the power line connecting the battery pack 50 and the power converter 111. The charging relay 110 switches between supplying and cutting off power between the battery pack 50 and the power converter 111 in response to a control signal from the control ECU 116.

[0028] The power converter 111 includes, for example, an AC / DC converter (not shown) and converts the AC power supplied from the charging equipment 5 via the charging cable 3 and inlet 112 into DC power, which is then output to the charging relay 110. When the hybrid vehicle 1 (battery pack 50) is externally charged using the power supplied from the charging equipment 5 (normal charging), the charging relay 110 is closed, and the power converter 111 controls the power supplied to the hybrid vehicle 1.

[0029] The inlet 122 receives DC power supplied from the charging equipment 9 when the charging cable 7 is connected to it. The charging relay 120 is electrically connected to the power line connecting the battery pack 50 and the inlet 122. The charging relay 120 switches the supply and interruption of power between the battery pack 50 and the inlet 122 according to a control signal from the control ECU 116. When the hybrid vehicle 1 (battery pack 50) is externally charged using power supplied from the charging equipment 9 (rapid charging), the charging relay 120 is closed, and the power supplied to the hybrid vehicle 1 is controlled by a controller installed in the charging equipment 9 (rapid charger).

[0030] The control ECU 116 comprises a processor 116a, a memory 116b, and a buffer (not shown). The control ECU 116 outputs control signals based on signals from each sensor and maps and programs stored in the memory 116b, and controls each device so that the hybrid vehicle 1 reaches a desired state. The control ECU 116 corresponds to an example of a “control device” in this disclosure.

[0031] Figure 2 illustrates an example of the arrangement of the engine 103, exhaust pipe 21, and battery pack 50 in this embodiment. Figure 2 is a bottom view of the hybrid vehicle 1 as seen from below. The engine 103 is located in the engine compartment at the front of the hybrid vehicle 1, and is positioned below the floor F so that the exhaust pipe 21 extends in the longitudinal direction of the vehicle. The battery pack 50 is located below the floor F of the hybrid vehicle 1 and is mounted under the floor of the hybrid vehicle 1. In this embodiment, the exhaust pipe 21 is located on the right side of the hybrid vehicle 1 below the floor F, and the battery pack 50 is located approximately in the center of the floor F, however, the exhaust pipe 21 may be located on the left side.

[0032] The battery pack 50 houses multiple battery stacks 55, a battery ECU 51, and a monitoring unit 52. The battery stack 55 is a battery pack in which battery cells (single cells) are stacked and electrically connected in series. The battery cells may be, for example, lithium-ion secondary batteries. The battery ECU 51 is, for example, an electronic device that controls the charging and discharging of the battery stack 55 (battery pack 50). The monitoring unit 52 is, for example, an electronic device that detects the voltage, input / output current, temperature, etc. of the battery stack 55 or battery cells. The battery pack 50 is also provided with a smoke exhaust passage 94 and a smoke exhaust valve 95.

[0033] Figure 3 is a schematic cross-sectional view showing the configuration of the battery pack 50. The battery pack 50 includes a plurality of battery stacks 55, a battery ECU 51, and a monitoring unit 52, all housed in a battery case 90 consisting of a lower case 91 and an upper case 92. The upper case 92 is provided with an opening, and a smoke exhaust valve 95 is provided in this opening. The battery cells are equipped with a safety mechanism that vents (releases) gas to the outside of the battery cell when the internal pressure rises abnormally due to gas generation, such as in the event of an abnormality. For example, if the battery cell is a prismatic battery, a safety valve (internal pressure release valve) is provided, and in the case of a laminated battery, the seal of the sealing part is released when the internal pressure rises. The smoke exhaust valve 95 discharges the gas to the outside of the battery case 90 when gas is released from the battery cell into the battery case 90. The smoke exhaust valve 95 may be, for example, a pressure release valve, or it may be a breathing membrane made of a breathable waterproof (moisture-permeable waterproof) sheet. If the smoke exhaust valve 95 is formed from the breathing membrane, the pressure inside the battery case 90 will be the external air pressure (atmospheric pressure).

[0034] The upper case 92 is provided with a smoke exhaust passage 94 (see the dashed line in Figures 2 and 3). The smoke exhaust passage 94 is a passage that guides the gas released from the battery cells to the smoke exhaust valve 95. The smoke exhaust passage 94 may be a duct fixed to the upper case 92, or it may be a space formed between the upper case 92 and the lower case 91 and battery stack 55. The smoke exhaust passage 94 is provided with a temperature sensor 53 for smoke detection. The temperature sensor 53 is provided to detect when gas is released from the battery cells and when the gas is released from the smoke exhaust valve 95 to the outside of the battery case 90. For example, when the temperature Te detected by the temperature sensor 53 becomes above a predetermined temperature B, it can be determined that gas has been released (smoke has been exhausted) from the battery cells.

[0035] Referring to Figure 2, the temperature sensor 53 is positioned between the battery ECU 51 and monitoring unit 52 and the exhaust pipe 21. The temperature sensor 53 is located in the exhaust passage 94 between the battery ECU 51 and monitoring unit 52 and the exhaust pipe 21. The battery pack 50 is located under the floor of the hybrid vehicle 1, and the exhaust pipe 21 is located under the floor of the hybrid vehicle 1 in the longitudinal direction. When the engine 103 is running, the heat from the exhaust gas discharged from the engine 103 is radiated from the exhaust pipe 21, warming the battery pack 50. The radiant heat from the exhaust pipe 21 heats the battery case 90, and the electronic components of the battery ECU 51 and monitoring unit 52 are heated, which may cause them to exceed their operating temperature limits.

[0036] In this embodiment, a temperature sensor 53 for smoke detection is provided in a smoke passage 94 located between the battery ECU 51 and monitoring unit 52 and the exhaust pipe 21. Since the temperature sensor 53 is located between the battery ECU 51 and monitoring unit 52 and the exhaust pipe 21, the temperature detected by the temperature sensor 53 also rises when the temperature of the battery ECU 51 and monitoring unit 52 rises due to radiant heat from the exhaust pipe 21. Therefore, the detection signal from the temperature sensor 53 can be used to detect the temperature rise of the electronic equipment (battery ECU 51, monitoring unit 52) ​​located inside the battery pack due to radiant heat from the exhaust pipe (exhaust passage) 21.

[0037] Figure 4 is a flowchart showing an example of battery pack temperature processing performed by the control ECU 116. This flowchart is repeated at predetermined intervals when the power switch of the hybrid vehicle 1 is ON. In step 10 (hereinafter, steps are abbreviated as "S"), it is determined whether or not an abnormality has occurred in the temperature sensor 53. The abnormality diagnosis of the temperature sensor 53 is performed by an initial check, for example, when the power switch is operated from the OFF state to the ON state. For example, in the initial check, a wire break is detected, and if an abnormality is found, an abnormality flag is stored in memory 116b. In S10, it is determined whether or not an abnormality flag is stored in memory 116b. If there is an abnormality in the temperature sensor 53, it is determined to be positive in S10, and the routine ends. If there is no abnormality in the temperature sensor 53, proceed to S11.

[0038] In S11, it is determined whether the temperature Te detected by the temperature sensor 53 is equal to or greater than a predetermined temperature A. The predetermined temperature A may be set lower (smaller) than the predetermined temperature B at which gas is detected (determined) to have been released from the battery cell. If the temperature Te is less than the predetermined temperature A, the condition is negated and the routine ends. If the temperature Te is equal to or greater than the predetermined temperature A, the process proceeds to S12.

[0039] In S12, it is determined whether the state in which the temperature Te is above a predetermined temperature A continues for a predetermined time. If the state in which the temperature Te is above a predetermined temperature A does not continue for the predetermined time, the process returns to S11. If the state in which the temperature Te is above a predetermined temperature A continues for the predetermined time, the determination is affirmative and the process proceeds to S13. The predetermined temperature A may be the operating guarantee temperature of the battery ECU 51 and the monitoring unit 52. If the operating guarantee temperatures of the battery ECU 51 and the monitoring unit 52 are different, the lower operating guarantee temperature may be used.

[0040] In S13, the diagnostic code for OBD (On-Board Diagnostics) is stored in the non-volatile memory area of ​​memory 116b. The diagnostic code stored in S13 indicates that the electronic equipment (battery ECU 51, monitoring unit 52) ​​was under high temperature conditions. In addition, in S13, processing may be performed to reduce the temperature of the exhaust gas emitted from the engine 103. For example, the load required on the engine 103 may be reduced. Alternatively, the ignition timing and fuel injection timing of the engine 103 may be adjusted to reduce the exhaust gas temperature. After processing S13, the routine ends. The storage of the diagnostic code and the processing to reduce the exhaust gas temperature in S13 are examples of "high temperature processing" in this disclosure.

[0041] According to this embodiment, the battery pack 50 located under the floor of the hybrid vehicle 1 includes a battery stack 55 made of stacked battery cells, a battery ECU 51 and a monitoring unit 52 (electronic equipment), and a temperature sensor 53 located between the battery ECU 51 and the monitoring unit 52 (electronic equipment) and the exhaust pipe (exhaust passage) 21. Since the temperature sensor 53 is located between the battery ECU 51 and the monitoring unit 52 (electronic equipment) and the exhaust pipe 21, it can suitably detect the temperature rise of the battery ECU 51 and the monitoring unit 52 (electronic equipment) due to radiant heat from the exhaust pipe 21.

[0042] According to this embodiment, the temperature sensor 53 is installed in the exhaust passage 94 that discharges gas released from the battery cells to the outside of the battery pack 50. Therefore, the temperature rise of the electronic equipment (battery ECU 51, monitoring unit 52) ​​due to radiant heat can be detected using the temperature sensor 53 for exhaust detection, so there is no need to install a new temperature sensor.

[0043] Furthermore, when the temperature Te detected by the temperature sensor 53 is above a predetermined temperature A, the control ECU 116 stores a diagnostic code in the memory 16b. Since the predetermined temperature A is set lower than the predetermined temperature B which detects the release of gas from the battery cell, the system can store as a diagnostic code that the temperature of the electronic equipment (battery ECU 51, monitoring unit 52) ​​has risen due to the radiant heat from the exhaust pipe 21. This allows the system to diagnose that the electronic equipment was under high-temperature conditions by referring to the diagnostic code using a service tool during service of the hybrid vehicle 1.

[0044] In the above embodiment, a temperature sensor 53 installed in the smoke exhaust passage 94 was used to detect that the temperature of the electronic equipment (battery ECU 51, monitoring unit 52) ​​had risen due to radiant heat from the exhaust pipe 21. However, the temperature sensor 53 may be installed anywhere other than the smoke exhaust passage 94, as long as it is positioned between the battery ECU 51 and monitoring unit 52 (electronic equipment) and the exhaust pipe (exhaust passage) 21. Alternatively, the processes from S11 to S12 in Figure 4 may be performed by the battery ECU 51, and the storage of the diagnostic code and the processing of the decrease in exhaust gas temperature may be performed by the control ECU 116. In this case, the battery ECU 51 also corresponds to an example of a "control device" in this disclosure.

[0045] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0046] 1 Hybrid vehicle, 21 Exhaust pipe (exhaust passage), 50 Battery pack (energy storage device), 51 Battery ECU, 52 Monitoring unit, 53 Temperature sensor, 55 Battery stack, 94 Smoke exhaust passage, 65 Smoke exhaust valve, 101, 102 Motor generator, 103 Engine, 104 Power split device, 105 Drive wheels, 106 PCU, 116 Control ECU, F Floor.

Claims

1. Internal combustion engines, An exhaust passage through which exhaust gas discharged from the internal combustion engine flows, The battery pack is located under the floor of the vehicle, A hybrid vehicle equipped with a control device, The aforementioned battery pack is A battery stack made of stacked battery cells, A smoke exhaust passage for discharging the gas released from the battery cell to the outside of the battery pack, Electronic devices and, Includes a temperature sensor positioned between the electronic device and the exhaust passage, The temperature sensor is a temperature sensor provided in the smoke exhaust passage, The control device executes high-temperature processing when the temperature detected by the temperature sensor is above a predetermined temperature. A hybrid vehicle in which the predetermined temperature is set lower than the temperature detected by the temperature sensor when the gas is released from the battery cell.

2. The hybrid vehicle according to claim 1, wherein the high-temperature processing includes storing a diagnostic code indicating that the electronic device was under high-temperature conditions.

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