vehicle

Abstract

To release a power-save mode in which output of a battery is restricted, at an appropriate timing, on the basis of a temperature of the battery.SOLUTION: A vehicle 1 comprises: an engine ENG; an exhaust system 30 into which exhaust gas flows from the engine ENG; a motor MOT that drives front wheels FW as driving wheels; a battery BAT that supplies electric power to the motor MOT through high-pressure cables 20 provided along the exhaust system 30; and a control device 50. The control device 50 sets a power-save mode in which output of the battery BAt is restricted when a temperature of the battery becomes a predetermined power-save transfer temperature or higher, and releases the power-save mode when the temperature of the battery falls below a power-save releasing temperature which is lower than the power-save transfer temperature in the power- save mode. Further, the control device 50 makes the power-save releasing temperature different depending on a temperature of the exhaust system 30 (for instance a temperature of a catalyst 32).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle. [Background technology]

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have been gaining momentum as a concrete measure against global climate change. With demands for reduced CO2 emissions and improved energy efficiency also emerging for automobiles and other vehicles, the electrification of drive sources is rapidly progressing. Specifically, vehicles equipped with an electric motor as a drive source for driving the drive wheels and a battery as a secondary battery capable of supplying power to the electric motor (hereinafter also referred to as "electric vehicles"; for example, electric vehicles) have been developed. Furthermore, some electric vehicles also include an internal combustion engine (for example, hybrid electric vehicles).

[0003] In an electric vehicle, power is supplied from a battery to an electric motor via a cable (also referred to as a "power cable") serving as a power line. Such a cable generates heat when a current flows through it, and it is undesirable for the cable to reach a high temperature due to this heat from the viewpoint of preventing deterioration and damage. Therefore, for example, Patent Document 1 listed below discloses a technology that calculates the temperature of an electric wire in a load circuit that supplies power output from a power source to a load to drive it, and when the calculated electric wire temperature reaches an allowable temperature for the electric wire, shuts off a switch means that switches between connecting and disconnecting the load circuit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-085469 Summary of the Invention [Problem to be solved by the invention]

[0005] In an electric vehicle, one possible method for preventing a cable that supplies battery power to a load such as an electric motor from becoming too hot is to switch to a power save mode that limits the battery output (i.e., limits the current flowing through the cable) when it is estimated that the temperature of the cable has reached a certain level. If such a power save mode is implemented in a vehicle, it is desirable to cancel the power save mode at an appropriate timing after switching to the power save mode, from the perspective of ensuring the marketability of the vehicle.

[0006] However, in conventional technology, in vehicles where power is supplied from the battery to the electric motor via a cable installed along the exhaust system through which exhaust gases from the internal combustion engine flow, it was difficult to release the power save mode, which limits battery output, at the appropriate time based on the battery temperature.

[0007] The present invention provides a vehicle in which power is supplied from a battery to an electric motor via a cable installed along an exhaust system through which exhaust gas from an internal combustion engine flows, and which makes it possible to cancel a power save mode that limits battery output at an appropriate time based on the battery temperature. [Means for solving the problem]

[0008] One aspect of the present invention is A vehicle comprising: an internal combustion engine; an exhaust system through which exhaust gas from the internal combustion engine flows; an electric motor as a drive source for driving drive wheels; a battery for supplying power to the electric motor via a cable provided along the exhaust system; and a control device, The control device When the temperature of the battery reaches or exceeds a predetermined power save transition temperature, the power save mode is set to limit the output of the battery. When the power save mode is set, if the temperature of the battery falls below a power save release temperature that is lower than the power save transition temperature, the power save mode is released; The power save release temperature is varied depending on the temperature of the exhaust system. When the temperature of the exhaust system is equal to or higher than a predetermined value, the power save release temperature is lowered compared to when the temperature of the exhaust system is lower than the predetermined value. Ru, It is a vehicle. [Effects of the Invention]

[0009] According to the present invention, in a vehicle in which power is supplied from a battery to an electric motor via a cable installed along an exhaust system through which exhaust gas from an internal combustion engine flows, a vehicle can be provided in which a power save mode that limits battery output can be released at an appropriate time based on the battery temperature. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic side view showing the overall structure of a vehicle 1 according to the present embodiment. [Figure 2] FIG. 2 is a view of the main parts of the vehicle 1 as seen from above. [Figure 3] FIG. 2 is a view of the main parts of the vehicle 1 as seen from below. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Figure 5] 4 is a flowchart showing an example of processing executed by a control device 50 of a vehicle 1. [Figure 6] 1A is a diagram showing the relationship between the battery temperature and the on (transition) / off (cancellation) of the power save mode, and FIG. 1B is a diagram showing the relationship between the on / off of the power save mode and the battery output upper limit value. [Figure 7] 10 is a flowchart showing an example of processing executed by a control device 50 of a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of a vehicle of the present invention will be described below with reference to the drawings. The drawings are to be viewed in the direction indicated by the reference numerals. In the following description, front, rear, left, right, and up and down are described according to the direction as seen by the driver of the vehicle, and in the drawings, the front of the vehicle is indicated as Fr, the rear as Rr, the left as L, the right as R, the top as U, and the bottom as D.

[0012] [vehicle] Vehicle 1 of this embodiment shown in Figure 1 is a four-wheel hybrid electric vehicle equipped with a pair of front wheels FW and a pair of rear wheels RW. As shown in Figure 1, vehicle 1 is divided into a passenger compartment 4, a luggage compartment 5, and a front room 6 in front of them by a floor panel 2 and a dash panel 3. Front seats 7 and rear seats 8 are provided in passenger compartment 4. A battery BAT is provided in luggage compartment 5, which is provided at the rear of the passenger compartment 4 and at the rear of the vehicle body. A drive unit 10 is provided in front of passenger compartment 4 and at the front of the vehicle body.

[0013] The drive unit 10 functions as a drive source that drives the drive wheels of the vehicle 1. In the vehicle 1, the front wheels FW are drive wheels and the rear wheels RW are driven wheels. That is, the drive unit 10 drives the front wheels FW. As will be described in detail later, the drive unit 10 includes a motor MOT as a drive source that drives the drive wheels (front wheels FW) of the vehicle 1, and an engine ENG as an internal combustion engine.

[0014] A control device 50 is also provided in the front room 6. The control device 50 is provided in a state in which it can communicate with each component of the vehicle 1, including the drive unit 10, for example, via an in-vehicle network (not shown), and performs overall control of the entire vehicle 1, including the drive unit 10. An example of the control performed by the control device 50 will be described later, so a description thereof will be omitted here.

[0015] The control device 50 is realized by an ECU (Electronic Control Unit) that includes, for example, a processor that performs various calculations, a storage device having a non-transitory storage medium that stores various information (data and programs), and an input / output device that controls input and output of data between the inside and outside of the control device 50. The control device 50 may be realized by one ECU or by multiple ECUs operating in cooperation with each other. The location where the control device 50 is located is not limited to the front room 6, and may be located in a place other than the front room 6, such as the passenger compartment 4 or the luggage compartment 5.

[0016] The vehicle 1 is further provided with various sensors. These sensors are provided in a state capable of communicating with the control device 50 and transmit detection signals indicating the detection values ​​of the respective sensors to the control device 50. This allows the control device 50 to acquire, from the various sensors, various pieces of information required for controlling the vehicle 1. Examples of the various sensors include a battery temperature sensor 15 and a catalyst temperature sensor 33, which will be described later, as well as a vehicle speed sensor (not shown) that detects the traveling speed of the vehicle 1 (hereinafter also referred to as "vehicle speed"), a temperature sensor (not shown) that detects the temperature around the vehicle 1 (hereinafter also referred to as "outside temperature"), a voltage sensor (not shown) that detects the output voltage of the battery BAT, and a current sensor (not shown) that detects the input / output current of the battery BAT.

[0017] 2, a drive unit 10 including a motor MOT, a power conversion device PCU, a transmission TM, and an engine ENG is disposed in the front of the vehicle body. Meanwhile, a battery BAT is disposed in the rear of the vehicle body. By disposing the battery BAT physically away from the drive unit 10, which may generate heat while the vehicle 1 is running, it is possible to prevent the battery BAT from becoming overheated due to the influence of heat from the drive unit 10.

[0018] The battery BAT has a plurality of storage cells connected in series or parallel, and is configured to be able to output a high voltage of, for example, 100 to 200 V. The storage cells of the battery BAT may be lithium-ion batteries or nickel-metal hydride batteries. The battery BAT is also provided with a battery temperature sensor 15 that detects the temperature of the battery BAT (hereinafter also referred to as "battery temperature").

[0019] The motor MOT is an electric motor (a so-called "traction motor"), for example an AC motor, that serves as a drive source for driving the drive wheels (i.e., the front wheels FW) of the vehicle 1. The motor MOT can be supplied with power from the battery BAT via a power conversion device PCU and a high-voltage cable 20, which will be described later. In other words, the battery BAT supplies power to the motor MOT via the high-voltage cable 20 and the power conversion device PCU.

[0020] In response to the supply of electric power, the motor MOT converts the supplied electric power into power and outputs it. The power output from the motor MOT is transmitted to the drive wheels of the vehicle 1 via a transmission TM, which will be described later, and is used to drive the vehicle 1. Furthermore, when braking the vehicle 1, the motor MOT can regenerate power from the drive wheels of the vehicle 1 to generate electricity. The electric power generated by the motor MOT is supplied to the battery BAT via the power conversion device PCU and high-voltage cable 20, and is used to charge the battery BAT.

[0021] The power conversion unit PCU converts the power exchanged between the battery BAT and the motor MOT. Specifically, the power conversion unit PCU converts the DC power supplied from the battery BAT into AC power and supplies it to the motor MOT. This makes it possible to supply appropriate power to the motor MOT.

[0022] The power conversion unit PCU also converts AC power supplied from the motor MOT into DC power and supplies it to the battery BAT. This makes it possible to supply appropriate power to the battery BAT. Furthermore, the power conversion unit PCU may also convert (i.e., step up or step down) the voltage of the power exchanged between the battery BAT and the motor MOT as necessary. The power conversion unit PCU is realized by an electronic circuit including, for example, an inverter and a DC / DC converter.

[0023] 2 and 3, one end of the high-voltage cable 20 is connected to the battery BAT, and the other end is connected to the power conversion device PCU, and functions as a power line for supplying power from the battery BAT to the motor MOT and for supplying power generated by the motor MOT to the battery BAT. The high-voltage cable 20 is realized, for example, by a cable in which a conductor formed by bundling a plurality of copper wires is covered with an insulator such as heat-resistant polyvinyl chloride.

[0024] In this embodiment, the high-voltage cable 20 is provided so as to extend from the battery BAT provided in the rear part of the vehicle body, passing under the floor panel 2 that constitutes the floor surface of the vehicle body, toward the drive unit 10 (i.e., the motor MOT and the power conversion device PCU) provided in the front part of the vehicle body. By routing the high-voltage cable 20 so as to pass under the floor panel 2, it becomes possible to easily connect the battery BAT provided in the rear part of the vehicle body and the drive unit 10 provided in the front part of the vehicle body via the high-voltage cable 20.

[0025] As will be described in detail later, the high-tension cable 20 is arranged along the exhaust system 30 through which exhaust gas from the engine ENG flows. This makes it possible to route the high-tension cable 20 by utilizing the floor tunnel 2a in which the exhaust system 30 is installed.

[0026] The engine ENG is an internal combustion engine such as a gasoline engine or a diesel engine, and outputs power generated by burning supplied fuel. The power output from the engine ENG is transmitted to the drive wheels (i.e., front wheels FW) of the vehicle 1 via a transmission TM, for example, and used to drive the vehicle 1. The power output from the engine ENG may also be transmitted to a motor MOT so that it can be used to generate electricity by the motor MOT.

[0027] The transmission TM is a power transmission device provided between the motor MOT and the engine ENG and the drive wheels (i.e., the front wheels FW) of the vehicle 1, and is, for example, a gear-type power transmission device that reduces the speed of the power output from the motor MOT or the engine ENG and transmits it to the drive wheels. Note that the gear ratio in the transmission TM may be configured to be changeable as appropriate in response to, for example, an instruction from the control device 50.

[0028] 2 and 3, an exhaust system 30 is connected to the engine ENG for discharging exhaust gas from the engine ENG to the outside. That is, the exhaust gas from the engine ENG flows through the exhaust system 30.

[0029] The exhaust system 30 is provided so as to extend from the engine ENG provided at the front of the vehicle body, passing under the floor panel 2, toward the rear of the vehicle body. Specifically, as shown in FIG. 4 , the exhaust system 30 is provided so as to protrude upward (in the direction indicated by "U" in FIG. 4 ) from the bottom surface of the floor panel 2 and to be housed in a floor tunnel 2a formed so as to extend from the front of the vehicle body toward the rear of the vehicle body. Similarly to the exhaust system 30, the high-voltage cable 20 is also provided so as to be housed in the floor tunnel 2a. More specifically, the high-voltage cable 20 and the exhaust system 30 are housed in the floor tunnel 2a so as to be aligned in the left-right direction of the vehicle 1, and are provided so as to extend in the front-rear direction of the vehicle 1 along the floor tunnel 2a. In this way, by providing the high-voltage cable 20 and the exhaust system 30 in the floor tunnel 2a, it is possible to ensure clearance between the high-voltage cable 20 and the exhaust system 30 and the road surface while suppressing an increase in the minimum ground clearance of the vehicle 1.

[0030] 3, the exhaust system 30 includes an exhaust manifold 31, a catalyst 32, a main pipe 34, and a silencer 35. The exhaust manifold 31 is a pipe that is connected at one end to the engine ENG and at the other end to the catalyst 32, and sends exhaust gas discharged from the cylinders of the engine ENG to the catalyst 32. The exhaust manifold 31 is also called a "front pipe."

[0031] The catalyst 32 is a purification device that filters harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) from the exhaust gas emitted from the engine ENG. The catalyst 32 is provided with a catalyst temperature sensor 33 that detects the temperature of the catalyst 32 (hereinafter also referred to as the "catalyst temperature"). As shown in FIG. 3, for example, the distance between the high-voltage cable 20 and the exhaust system 30 is closest near the catalyst 32. For this reason, the high-voltage cable 20 may be affected by heat from the catalyst 32.

[0032] The main pipe 34 has one end connected to the catalyst 32 and the other end open to the outside, and is a pipe that releases into the atmosphere the exhaust gas purified by the catalyst 32. In addition, a silencer 35 is provided in the middle of the main pipe 34 to muffle the exhaust noise made when the exhaust gas is released into the atmosphere.

[0033] Generally, the exhaust gas discharged from the engine ENG is at a high temperature, so when the engine ENG is operating, the temperature of the exhaust system 30 also becomes high.

[0034] [Example of control performed by the control device] Next, an example of control performed by the control device 50 will be described. The high-voltage cable 20 can generate heat when a current flows through it, but it is undesirable for the high-voltage cable 20 to reach a high temperature from the viewpoint of preventing deterioration and damage. Therefore, the control device 50 has a power save mode as a control mode that limits the output of the battery BAT, and transitions to the power save mode based on the battery temperature.

[0035] Here, the output of the battery BAT can be, for example, the amount of power output from the battery BAT per unit time. In the following explanation, the power in the direction in which current flows from the battery BAT to the motor MOT (i.e., the power that powers the motor MOT; hereinafter also referred to as "powering side power") is taken as a positive (+) direction, and the power in the direction in which current flows from the motor MOT to the battery BAT (i.e., the power that charges the battery BAT; hereinafter also referred to as "regeneration side power") is taken as a negative (-) direction.

[0036] The battery temperature increases as the output of the battery BAT increases, i.e., as the amount of current flowing through the high-voltage cable 20 per unit time increases. Therefore, when the battery temperature is relatively high, it is considered that the temperature of the high-voltage cable 20 (hereinafter also referred to as "cable temperature") is also relatively high.

[0037] Therefore, when the battery temperature reaches or exceeds a predetermined power save transition temperature, the control device 50 assumes that the cable temperature has also risen to a certain level, and transitions to the power save mode. As a result, after the battery temperature reaches the power save transition temperature, the output of the battery BAT can be limited to reduce the amount of current flowing through the high-voltage cable 20 per unit time, reducing heat generation in the high-voltage cable 20 due to this current and suppressing a temperature rise in the high-voltage cable 20.

[0038] The power save transition temperature, which is the condition for transitioning to the power save mode, is determined in advance by, for example, the manufacturer of the vehicle 1 or the control device 50, taking into consideration the heat resistance of the high-voltage cable 20, and is set in the control device 50. In this embodiment, the power save transition temperature is set to X1 [°C].

[0039] For example, the control device 50 sets an upper limit value for the amount of power output from the battery BAT per unit time (hereinafter also referred to as "battery output upper limit value") and controls the motor MOT and the power conversion device PCU so that the output of the battery BAT does not exceed this battery output upper limit value. When the control device 50 is in the power save mode, the absolute value of the battery output upper limit value that is set is smaller than when the control device 50 is not in the power save mode (i.e., during normal operation).

[0040] In this embodiment, the control device 50 sets the battery output upper limit value for power running side power to P11 [kW] (where P11 > 0; see also FIG. 6, for example) under normal circumstances, and to P12 [kW] (where P12 > P11; see also FIG. 6, for example) under power save mode. The control device 50 also sets the battery output upper limit value for regeneration side power to -P21 [kW] (where -P21 < 0; see also FIG. 6, for example) under normal circumstances, and to -P22 [kW] (where -P22 < -P21; see also FIG. 6, for example) under power save mode.

[0041] In this way, in the power save mode, the absolute values ​​of the battery output upper limit values ​​for the power running side power and the regeneration side power are made smaller than those in normal operation, thereby making it possible to limit the output of the battery BAT. Note that the above P11, P12, -P21, -P22 are determined in advance by, for example, the manufacturer of the vehicle 1 or the control device 50, taking into consideration the heat resistance of the high-voltage cable 20, and are set in the control device 50.

[0042] The control device 50 calculates the driving force required to run the vehicle 1 (hereinafter also referred to as "required driving force") based on the operation amount of the accelerator pedal of the vehicle 1 and the vehicle speed, and outputs power equivalent to the required driving force from the drive unit 10 (at least one of the motor MOT and the engine ENG). For example, if power equivalent to the required driving force can be secured by the motor MOT alone, the control device 50 causes the vehicle 1 to run using only the motor MOT, while keeping the engine ENG idle during that time. This can improve the fuel efficiency and NV (Noise, Vibration) performance of the vehicle 1.

[0043] In such a vehicle 1, when the vehicle is in the power save mode, the output of the battery BAT is limited, and the upper limit of the power that the motor MOT can output is also reduced. For this reason, if the power save mode continues unnecessarily for a long period of time, this can lead to a decrease in drivability due to the occurrence of so-called "sluggishness" caused by the low upper limit of the power that the motor MOT can output, and to a decrease in fuel economy and NV performance due to the engine ENG being more likely to operate, which can reduce the marketability of the vehicle 1. Therefore, it is desirable to cancel the power save mode at an appropriate time.

[0044] Therefore, the control device 50 is configured to cancel the power save mode when the battery temperature falls below a power save release temperature that is lower than the power save transition temperature while the power save mode is in effect, and varies the power save release temperature depending on the temperature of the exhaust system 30. This allows the control device 50 to cancel the power save mode, which limits the output of the battery BAT, at an appropriate timing based on the battery temperature in the vehicle 1 in which power is supplied from the battery BAT to the motor MOT via a high-voltage cable 20 provided along the exhaust system 30 through which exhaust gas from the engine ENG flows.

[0045] A specific example of transition to and release from the power save mode by the control device 50 will be described below with reference to Figures 5 and 6. Figure 5 is a flowchart showing an example of processing executed by the control device 50. For example, while the ignition power of the vehicle 1 is on, the control device 50 repeatedly executes the series of processing shown in Figure 5 at a predetermined cycle.

[0046] 6A shows the relationship between the battery temperature and the ON (transition) / OFF (cancellation) of the power save mode, and the bottom diagram (b) shows the relationship between the ON / OFF of the power save mode and the battery output upper limit. In FIG. 6, the solid line represents an example of when the power save mode is cancelled by executing the processes of steps S15 and S16, which will be described later. On the other hand, in FIG. 6, the dashed line represents an example of when the power save mode is cancelled by executing the processes of steps S17 and S16, which will be described later.

[0047] [Example of processing performed by the control device] 5, the control device 50 first determines whether the control mode for output control of the battery BAT is in the power save mode (step S11). If the control mode is in the power save mode (step S11: Yes), the control device 50 proceeds to the process of step S14.

[0048] On the other hand, if the power save mode is not selected (step S11: No), the control device 50 determines whether the battery temperature detected by the battery temperature sensor 15 is equal to or higher than X1 [°C], which is defined as the power save transition temperature (step S12). If the battery temperature is lower than X1 [°C] (step S12: No), the control device 50 ends the series of processes shown in FIG.

[0049] On the other hand, if the battery temperature becomes X1 [°C] or higher (step S12: Yes), the control device 50 transitions to the power save mode (step S13). As a result, the control device 50 transitions to the power save mode when the battery temperature rises and reaches X1 [°C], for example, as shown at time T1 in FIG. 6(a). Therefore, as shown in FIG. 6(b), the battery output upper limit value for the power running side power is P11 [kW] before time T1, but becomes P12 [kW] from time T1 onwards. In addition, the battery output upper limit value for the regeneration side power is −P21 [kW] before time T1, but becomes −P22 [kW] from time T1 onwards.

[0050] In this way, from time T1, the battery output upper limit values ​​for both the power running side power and the regenerative side power become smaller, and therefore the upper limit value of the power that the motor MOT can output and the upper limit value of the amount of power that the motor MOT can generate per unit time also become smaller.

[0051] Then, by transitioning to the power save mode at time T1 when the battery temperature reaches X1 [°C], the battery temperature may gradually decrease after time T1, as shown in Fig. 6(a). Also, although not shown, the cable temperature may also gradually decrease after time T1, similar to the battery temperature.

[0052] Next, the control device 50 determines whether or not the catalyst temperature detected by the catalyst temperature sensor 33 is equal to or higher than a predetermined Xa [°C] (where Xa > 0) (step S14). Here, Xa is, for example, a temperature set for the control device 50 by the manufacturer of the vehicle 1 or the control device 50 as a condition for determining that the exhaust system 30 including the catalyst 32 is in a high-temperature state.

[0053] If the catalyst temperature is equal to or higher than Xa [°C] (step S14: Yes), the control device 50 determines whether or not the battery temperature detected by the battery temperature sensor 15 is lower than a predetermined X2 [°C] (where X2 < X1) (step S15). Here, X2 is, for example, a temperature preset for the control device 50 by the manufacturer of the vehicle 1 or the control device 50 as a power save release temperature when the catalyst temperature is equal to or higher than Xa [°C], that is, when the exhaust system 30 including the catalyst 32 is in a high-temperature state.

[0054] If the battery temperature is not lower than X2 [°C] (step S15: No), the control device 50 ends the series of processes shown in FIG. 5. On the other hand, if the battery temperature is lower than X2 [°C] (step S15: Yes), the control device 50 releases the power save mode (step S16) and ends the series of processes shown in FIG. 5.

[0055] As described above, an example in which the power save mode is released when the processes of step S15 and step S16 are executed is shown by a solid line in FIG. 6. That is, in this case, as shown at time T2 in FIG. 6(a), when the battery temperature drops and reaches X2 [°C], the control device 50 releases the power save mode. As a result, as shown in FIG. 6(b), the battery output upper limit value for the power running side power returns to P11 [kW] from time T2. Also, the battery output upper limit value for the regeneration side power also returns to -P21 [kW] from time Tl.

[0056] Thus, when the catalyst temperature is Xa [°C] or higher, the power save mode is canceled at time T2 when the battery temperature reaches X2 [°C], so that the battery temperature can gradually increase after time T2, as shown by the solid line in FIG. 6(a). Also, although illustration is omitted, in this case, the cable temperature can also gradually increase after time T2, similar to the battery temperature.

[0057] On the other hand, when the catalyst temperature is less than Xa [°C] (step S14: No), the control device 50 determines whether or not the battery temperature detected by the battery temperature sensor 15 is less than a predetermined X3 [°C] (where X2 < X3 < X1) (step S17). Here, X3 is, for example, the power save release temperature when the catalyst temperature is less than Xa [°C], that is, when the exhaust system 30 including the catalyst 32 is not in a high temperature state (in other words, in a non-high temperature state), and is a temperature set in advance for the control device 50 by the manufacturer of the vehicle 1 or the control device 50.

[0058] If the battery temperature is not less than X3 [°C] (step S17: No), the control device 50 ends the series of processes shown in FIG. 5. On the other hand, if the battery temperature is less than X3 [°C] (step S17: Yes), the control device 50 proceeds to the process of step S16 to cancel the power save mode and ends the series of processes shown in FIG. 5.

[0059] As described above, an example in which the power save mode is released by executing the processes of steps S17 and S16 is shown by the dashed-dotted line in FIG. 6. That is, in this case, as shown at time T3 in FIG. 6(a), the control device 50 releases the power save mode when the battery temperature drops to X3 [°C]. Because X3 [°C] is higher than X2 [°C], the power save mode is released at time T3, which is before time T2. As a result, in this case, as shown in FIG. 6(b), the battery output upper limit value for the power running side power returns to P11 [kW] from time T3, which is before time T2. Furthermore, the battery output upper limit value for the regeneration side power also returns to −P21 [kW] from time T3, which is before time T2.

[0060] In this way, when the catalyst temperature is below Xa [°C], the power save mode is released at time T3 when the battery temperature reaches X3 [°C], and the battery temperature may gradually increase after time T3, as shown by the dashed line in Figure 6(a). Also, although not shown, in this case, the cable temperature may also gradually increase after time T3, similar to the battery temperature.

[0061] As described above, in the vehicle 1, the high-voltage cable 20 is arranged along the exhaust system 30, thereby facilitating the connection between the battery BAT and the drive unit 10 via the high-voltage cable 20. When the high-voltage cable 20 is arranged along the exhaust system 30 in this way, the high-voltage cable 20 may be affected by heat from the exhaust system 30. For this reason, even when the battery temperature is relatively low (for example, below X3°C but higher than X2°C), it is conceivable that the cable temperature may be relatively high due to the influence of heat from the exhaust system 30.

[0062] Therefore, the control device 50 is configured to cancel the power save mode when the battery temperature falls below the power save cancellation temperature, and the power save cancellation temperature is made to vary depending on the temperature (e.g., catalyst temperature) of the exhaust system 30. This makes it possible to cancel the power save mode based on the battery temperature at an appropriate timing that takes into account the temperature of the exhaust system 30, even if the high-voltage cable 20 is installed along the exhaust system 30.

[0063] More specifically, in this embodiment, when the exhaust system 30 is in a high temperature state (for example, when the catalyst temperature is equal to or higher than Xa [°C]), the power save release temperature is set lower than when the exhaust system 30 is not in a high temperature state (for example, when the catalyst temperature is lower than Xa [°C]). As a result, even if the battery temperature is relatively low, if it is assumed that the cable temperature is relatively high due to the influence of heat from the exhaust system 30, the power save mode can be continued without being released. Therefore, it is possible to prevent the power save mode from being released even when the cable temperature is relatively high, resulting in the high-voltage cable 20 becoming hot. On the other hand, when the exhaust system 30 is not in a high temperature state, it is assumed that the cable temperature is also relatively low if the battery temperature is relatively low. Therefore, by raising the power save release temperature, the power save mode can be released more quickly, increasing the opportunities to utilize the inherent output performance of the battery BAT, and improving the marketability of the vehicle 1.

[0064] Furthermore, the battery BAT of an electric vehicle such as the vehicle 1 is generally provided with a battery temperature sensor 15 that detects the battery temperature. Therefore, the control device 50 transitions to and releases from the power save mode based on the battery temperature detected by the battery temperature sensor 15. This makes it possible to transition to and release from the power save mode without providing a temperature sensor that detects the cable temperature in the high-voltage cable 20 or having the control device 50 perform calculations to estimate the cable temperature. Therefore, it is possible to transition to and release from the power save mode while preventing the configuration of the vehicle 1 from becoming complicated and reducing the processing load on the control device 50.

[0065] Furthermore, a catalyst 32 in an exhaust system 30 of a vehicle equipped with an engine ENG (internal combustion engine) such as the vehicle 1 is generally provided with a catalyst temperature sensor 33 that detects the catalyst temperature. Therefore, the control device 50 uses the catalyst temperature detected by the catalyst temperature sensor 33 as the temperature of the exhaust system 30. This eliminates the need to add a temperature sensor separate from the catalyst temperature sensor 33 to the exhaust system 30 in order to acquire the temperature of the exhaust system 30, and makes it possible to prevent the configuration of the vehicle 1 from becoming complicated.

[0066] [Variations] Next, a modified example of the above-described embodiment will be described. In the following, parts common to the above-described embodiment will be given the same reference numerals, and their description will be omitted or simplified as appropriate.

[0067] In the embodiment described above, the catalyst temperature detected by catalyst temperature sensor 33 is used as the temperature of exhaust system 30, and the power save release temperature is varied depending on the catalyst temperature. In contrast, in the modified example described below, a setting temperature, which is an evaluation value for setting the power save release temperature, is derived based on at least one of the temperature around vehicle 1 (i.e., outside temperature) and the traveling speed of vehicle 1 (i.e., vehicle speed), and the temperature of exhaust system 30 (e.g., catalyst temperature), and the power save release temperature is varied depending on the derived setting temperature. This makes it possible to deactivate the power save mode based on battery temperature at a more appropriate timing that takes into account at least one of the outside temperature and vehicle speed of vehicle 1 in addition to the temperature of exhaust system 30.

[0068] [Example of processing executed by the control device of the modified example] 7 is a flowchart showing an example of processing executed by the modified control device 50. For example, as shown in FIG. 7, the modified control device 50 performs processing of steps S21 and S22 instead of the processing of step S14 in the flowchart shown in FIG.

[0069] In step S21, the control device 50 derives a setting temperature for setting the power save release temperature based on the catalyst temperature, which is an example of the temperature of the exhaust system 30, the outside air temperature of the vehicle 1, and the vehicle speed (step S21). That is, the high-voltage cable 20 may be affected not only by the heat from the exhaust system 30, but also by the outside air temperature and wind generated by the vehicle 1. For example, when the outside air temperature of the vehicle 1 is low, the temperature rise of the high-voltage cable 20 may be suppressed compared to when the outside air temperature is high. Similarly, when the vehicle speed of the vehicle 1 is high, the amount of wind blowing against the high-voltage cable 20 per unit time is greater than when the vehicle speed is low, and therefore the temperature rise of the high-voltage cable 20 may be suppressed compared to when the vehicle speed is low.

[0070] Therefore, the control device 50 derives a setting temperature based on the catalyst temperature, the outside air temperature of the vehicle 1, and the vehicle speed, taking into consideration the influence of these factors on the cable temperature. The setting temperature may be derived using a map stored in advance in a storage device of the control device 50, or may be derived using a predetermined calculation formula that includes the catalyst temperature, the outside air temperature of the vehicle 1, and the vehicle speed as parameters.

[0071] After deriving the setting temperature through the processing of step S21, the control device 50 determines whether the derived setting temperature is equal to or higher than a predetermined value Xb [°C] (where Xb>0) (step S22). Here, Xb is a temperature set for the control device 50 by, for example, the manufacturer of the vehicle 1 or the control device 50.

[0072] If the setting temperature is equal to or higher than Xb [°C] (step S22: Yes), the control device 50 proceeds to the process of step S15. On the other hand, if the setting temperature is lower than Xb [°C] (step S22: No), the control device 50 proceeds to the process of step S17.

[0073] As described above, the high-voltage cable 20 can be affected by the heat from the exhaust system 30, as well as the outside temperature and wind of the vehicle 1. Therefore, the control device 50 of the modified example derives a setting temperature for setting the power save release temperature based on the temperature of the exhaust system 30 (e.g., catalyst temperature) and at least one of the outside temperature and vehicle speed of the vehicle 1, and sets the power save release temperature using the derived setting temperature. This makes it possible to release the power save mode based on the battery temperature at a more appropriate timing that takes into account at least one of the outside temperature and vehicle speed of the vehicle 1 in addition to the temperature of the exhaust system 30.

[0074] Although the present invention has been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also fall within the technical scope of the present invention. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0075] For example, in the processing of step S21 of the above-described modified example, the set temperature is derived based on the catalyst temperature, the outside air temperature of the vehicle 1, and the vehicle speed, but this is not limiting. For example, the set temperature may be derived taking into consideration the operating state of the engine ENG (for example, the rotation speed) in addition to the temperature of the exhaust system 30 (for example, the catalyst temperature), the outside air temperature of the vehicle 1, and the vehicle speed. That is, when the engine ENG is in a high load state, it is expected that the temperature of the exhaust gas exhausted from the engine ENG will also be higher, so the set temperature may be derived accordingly. In this way, it is possible to cancel the power save mode based on the battery temperature at a more appropriate time.

[0076] This specification and the like describes at least the following: Components corresponding to those in the above-described embodiments are shown in parentheses, but the present invention is not limited to these.

[0077] (1) A vehicle (vehicle 1) including an internal combustion engine (engine ENG), an exhaust system (exhaust system 30) through which exhaust gas from the internal combustion engine flows, an electric motor (motor MOT) as a drive source for driving drive wheels (front wheels FW), a battery (battery BAT) that supplies power to the electric motor via a cable (high-voltage cable 20) provided along the exhaust system, and a control device (control device 50), The control device When the temperature of the battery reaches or exceeds a predetermined power save transition temperature (X1 [°C]), the power save mode is set to limit the output of the battery. When the power save mode is set, if the temperature of the battery falls below a power save release temperature (X2 [°C], X3 [°C]) which is lower than the power save transition temperature, the power save mode is released, The power save release temperature is varied depending on the temperature of the exhaust system. vehicle.

[0078] According to (1), by arranging a cable that supplies power from the battery to the electric motor along the exhaust system, it is possible to easily connect the battery and the electric motor via the cable. When the cable is arranged along the exhaust system in this way, the cable may be affected by heat from the exhaust system. Therefore, even when the battery temperature is relatively low, it is possible that the cable temperature may be relatively high due to the heat from the exhaust system. Therefore, the control device, assuming a configuration in which the power save mode is released when the battery temperature falls below the power save release temperature, varies the power save release temperature depending on the temperature of the exhaust system. This makes it possible to release the power save mode based on the battery temperature at an appropriate time that takes the exhaust system temperature into consideration, even when the cable that supplies power from the battery to the electric motor is arranged along the exhaust system.

[0079] (2) The vehicle according to (1), the exhaust system is provided so as to extend from the internal combustion engine provided at the front part of the vehicle body, passing under the vehicle body, toward the rear part of the vehicle body, The cable is provided so as to extend from the battery provided in the rear portion of the vehicle body, passing under the vehicle body, toward the electric motor provided in the front portion of the vehicle body. vehicle.

[0080] According to (2), it is possible to easily connect the battery provided at the rear of the vehicle body and the electric motor provided at the front of the vehicle body via a cable.

[0081] (3) A vehicle as described in (1) or (2), The vehicle further includes a power conversion device (power conversion unit PCU) that converts power exchanged between the battery and the electric motor, one end of the cable is connected to the battery and the other end is connected to the power conversion device; the battery supplies power to the electric motor via the cable and the power converter; vehicle.

[0082] According to (3), it is possible to supply appropriate power to the electric motor.

[0083] (4) A vehicle according to any one of (1) to (3), the control device lowers the power save release temperature when the temperature of the exhaust system is equal to or higher than a predetermined value compared to when the temperature of the exhaust system is lower than the predetermined value; vehicle.

[0084] When the temperature of the exhaust system is equal to or higher than a predetermined value (i.e., when the exhaust system is in a high temperature state), it is assumed that the temperature of the cable will be in a high temperature state due to the heat from the exhaust system, even if the temperature of the battery is in a low temperature state. According to (4), by lowering the power save release temperature when the temperature of the exhaust system is equal to or higher than a predetermined value compared to when the temperature of the exhaust system is below a predetermined value, it is possible to prevent the power save mode from being released even when the temperature of the cable is in a high temperature state due to the heat from the exhaust system, and to prevent the cable from becoming hot.

[0085] (5) A vehicle according to any one of (1) to (4), The exhaust system includes a catalyst (catalyst 32) provided with a temperature sensor (catalyst temperature sensor 33), the temperature of the exhaust system is the temperature of the catalyst detected by the temperature sensor; vehicle.

[0086] Generally, a temperature sensor is provided in the catalyst of the exhaust system. According to (5), the temperature of the catalyst detected by the catalyst temperature sensor is used as the temperature of the exhaust system, so there is no need to add a new temperature sensor to obtain the temperature of the exhaust system, and the vehicle configuration can be prevented from becoming complicated.

[0087] (6) A vehicle according to any one of (1) to (5), The control device deriving a setting temperature for setting the power save release temperature based on at least one of an air temperature around the vehicle and a traveling speed of the vehicle, and a temperature of the exhaust system; The power save release temperature is varied depending on the setting temperature. vehicle.

[0088] According to (6), it is possible to deactivate the power save mode based on the battery temperature at a more appropriate timing that takes into account not only the temperature of the exhaust system but also at least one of the air temperature around the vehicle and the vehicle's traveling speed. [Explanation of symbols]

[0089] 1 vehicle 20 High voltage cable (cable) 30 Exhaust System 32 Catalyst 33 Catalyst temperature sensor (temperature sensor) 50 Control device BAT Battery ENG Engine (internal combustion engine) MOT motor (electric motor) PCU power conversion unit

Claims

1. A vehicle comprising: an internal combustion engine; an exhaust system through which exhaust gas from the internal combustion engine flows; an electric motor as a drive source for driving drive wheels; a battery for supplying power to the electric motor via a cable provided along the exhaust system; and a control device, The control device When the temperature of the battery reaches or exceeds a predetermined power save transition temperature, the power save mode is set to limit the output of the battery. When the power save mode is set, if the temperature of the battery falls below a power save release temperature that is lower than the power save transition temperature, the power save mode is released; The power save release temperature is varied depending on the temperature of the exhaust system, and when the temperature of the exhaust system is equal to or higher than a predetermined value, the power save release temperature is lowered compared to when the temperature of the exhaust system is lower than the predetermined value. vehicle.

2. 2. The vehicle according to claim 1, the exhaust system is provided so as to extend from the internal combustion engine provided at the front part of the vehicle body, passing under the vehicle body, toward the rear part of the vehicle body, The cable is provided so as to extend from the battery provided in the rear portion of the vehicle body, passing under the vehicle body, toward the electric motor provided in the front portion of the vehicle body. vehicle.

3. 3. A vehicle according to claim 1 or 2, The vehicle further includes a power conversion device that converts power exchanged between the battery and the electric motor, one end of the cable is connected to the battery and the other end is connected to the power conversion device; the battery supplies power to the electric motor via the cable and the power converter; vehicle.

4. A vehicle according to any one of claims 1 to 3, the exhaust system includes a catalyst provided with a temperature sensor; the temperature of the exhaust system is the temperature of the catalyst detected by the temperature sensor; vehicle.

5. A vehicle according to any one of claims 1 to 4, The control device deriving a setting temperature for setting the power save release temperature based on at least one of an air temperature around the vehicle and a traveling speed of the vehicle, and a temperature of the exhaust system; The power save release temperature is varied depending on the setting temperature. vehicle.

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