Vehicle

Abstract

The present application releases an energy saving mode that restricts the output of a battery at an appropriate timing based on the temperature of the battery. A vehicle (1) is provided with an engine (ENG), an exhaust system (30) through which exhaust gas from the engine (ENG) flows, a motor (MOT) that drives a front wheel (FW) that is a drive wheel, a battery (BAT) that supplies electric power to the motor (MOT) via a high-voltage cable (20) provided along the exhaust system (30), and a control device (50). The control device (50) sets an energy saving mode that restricts the output of the battery (BAT) when the battery temperature becomes equal to or higher than a prescribed energy saving shift temperature, and releases the energy saving mode when the battery temperature is lower than an energy saving release temperature that is lower than the energy saving shift temperature while the energy saving mode is set. Furthermore, the control device (50) makes the energy saving release temperature different depending on the temperature of the exhaust system (30), such as the temperature of a catalyst section (32).

Description

Technical Field

[0001] This invention relates to a vehicle. Background Technology

[0002] In recent years, efforts to achieve a low-carbon or decarbonized society have become increasingly active as a concrete countermeasure to global climate change. For vehicles such as automobiles, there are demands for reduced CO2 emissions and improved energy efficiency, leading to rapid development in the electrification of drive sources. Specifically, vehicles equipped with an electric motor as the drive source for the drive wheels and a secondary battery that supplies power to the motor (hereinafter also referred to as "electric vehicles," such as electric cars) have been developed. Furthermore, some electric vehicles also incorporate internal combustion engines (such as hybrid electric vehicles).

[0003] In electric vehicles, power is supplied from the battery to the motor via cables (also called "power cables") that serve as power lines. These cables heat up due to the flow of current. From the viewpoint of suppressing degradation and damage, it is undesirable for the cables to become high-temperature due to this heating. Therefore, for example, Patent Document 1 discloses a technique that calculates the temperature of the wires supplying power from the power source to the load circuit to drive the load, and disconnects the connection to the load circuit and shuts off the switching unit when the calculated wire temperature reaches the wire's permissible temperature.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-085469 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] As a method to prevent cables supplying battery power to loads such as motors in electric vehicles from becoming excessively hot, one approach is to consider switching to an energy-saving mode that limits battery output (i.e., limits the current flowing in the cables) when the cable temperature is presumed to be high enough. When such an energy-saving mode is incorporated into a vehicle, from the viewpoint of ensuring vehicle marketability, it is desirable to deactivate the energy-saving mode at an appropriate time after switching to it.

[0009] However, in the prior art, in vehicles where electricity is supplied from the battery to the electric motor via a cable installed along the exhaust system that supplies exhaust gas from the internal combustion engine, it is difficult to release the energy-saving mode that limits the battery output at the appropriate time based on the battery temperature.

[0010] The present invention provides a vehicle in which power is supplied from a battery to an electric motor via a cable arranged along an exhaust system that supplies exhaust gas from an internal combustion engine, and an energy-saving mode that restricts battery output can be deactivated at appropriate times based on the temperature of the battery.

[0011] Solution for solving the problem

[0012] One aspect of the present invention is as follows:

[0013] A vehicle comprising: an internal combustion engine; an exhaust system for supplying exhaust gas flow from the internal combustion engine; an electric motor as a drive source for driving drive wheels; a battery for supplying power to the electric motor via a cable disposed along the exhaust system; and a control device, wherein...

[0014] The control device performs the following control:

[0015] When the battery temperature reaches or exceeds a predetermined energy-saving transition temperature, an energy-saving mode is established that limits the battery's output.

[0016] When the energy-saving mode is set, if the battery temperature is lower than the energy-saving deactivation temperature (which is lower than the energy-saving transfer temperature), the energy-saving mode is deactivated, and

[0017] The energy-saving release temperature varies depending on the temperature of the exhaust system.

[0018] Invention Effects

[0019] According to the present invention, a vehicle is provided in which power is supplied from a battery to an electric motor via a cable arranged along an exhaust system that supplies exhaust gas from an internal combustion engine, and an energy-saving mode that restricts battery output is released at an appropriate time based on the temperature of the battery. Attached Figure Description

[0020] Figure 1 This is a schematic side view showing the overall structure of vehicle 1 according to this embodiment.

[0021] Figure 2 This is a view of the main parts of vehicle 1 from above.

[0022] Figure 3 This is a diagram showing the main parts of vehicle 1 from below.

[0023] Figure 4 yes Figure 3 A cross-sectional view at line AA.

[0024] Figure 5 This is a flowchart illustrating an example of the processing performed by the control device 50 of vehicle 1.

[0025] Figure 6 (a) is a graph showing the relationship between battery temperature and the activation (transfer) / deactivation (cancellation) of power saving mode, and (b) is a graph showing the relationship between the activation / deactivation of power saving mode and the upper limit of battery output.

[0026] Figure 7 This is a flowchart illustrating an example of the processing performed by the control device 50 in a modified example.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1 vehicle

[0029] 20V high-voltage cable (cable)

[0030] 30 exhaust system

[0031] 32 Catalyst Section

[0032] 33. Catalyst section temperature sensor (temperature sensor)

[0033] 50 control devices

[0034] BAT Battery

[0035] ENG engine (internal combustion engine)

[0036] MOT motor (electric motor)

[0037] PCU power conversion unit. Detailed Implementation

[0038] Hereinafter, one embodiment of the vehicle of the present invention will be described with reference to the accompanying drawings. The drawings are viewed according to the orientation indicated by the reference numerals. Furthermore, in the following description, front, back, left, right, up, and down are described according to the direction of view of the driver of the vehicle. In the drawings, the front of the vehicle is denoted as Fr, the rear as Rr, the left as L, the right as R, the top as U, and the bottom as D.

[0039] [vehicle]

[0040] Figure 1 The vehicle 1 shown in this embodiment is a four-wheel hybrid electric vehicle, each equipped with a pair of front wheels (FW) and rear wheels (RW). Figure 1 As shown, vehicle 1 is divided into a passenger compartment 4, a trunk 5, and a front compartment 6 by a floor 2 and a front bulkhead 3. Front seats 7 and rear seats 8 are provided in the passenger compartment 4. A battery pack BAT is located in the trunk 5, which is situated behind the passenger compartment 4 and at the rear of the vehicle. A drive unit 10 is located in the front compartment 6, which is situated in front of the passenger compartment 4 and at the front of the vehicle.

[0041] The drive unit 10 functions as the drive source for 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. The drive unit 10 is configured to include a motor MOT, which serves as the drive source for the drive wheels (front wheels FW) of the vehicle 1, and an engine ENG, which serves as an internal combustion engine, as detailed later.

[0042] In addition, a control device 50 is provided in the front compartment 6. The control device 50 is configured to communicate with each component of the vehicle 1, including the drive unit 10, via an in-vehicle network (not shown), and to uniformly control the vehicle 1 as a whole, including the drive unit 10. An example of the control performed by the control device 50 will be described later, so it is omitted here.

[0043] The control device 50 is implemented, for example, by an ECU (Electronic Control Unit). This ECU includes: a processor for performing various calculations; a storage device with a non-transitory storage medium for storing various information (data, programs); and an input / output device for controlling the input and output of internal and external data of the control device 50. Furthermore, the control device 50 can be implemented by a single ECU or by multiple ECUs operating in coordination. Additionally, the location of the control device 50 is not limited to the front compartment 6; it can also be located in places other than the front compartment 6, such as the passenger compartment 4 or the trunk 5.

[0044] Vehicle 1 is also equipped with various sensors. These sensors are configured to communicate with control device 50, sending detection signals representing their own detection values ​​to control device 50. Thus, control device 50 can obtain various information required to control vehicle 1 from various sensors. Examples of various sensors include, in addition to battery temperature sensor 15 and catalyst temperature sensor 33 described later, vehicle speed sensor (not shown) that detects the driving speed of vehicle 1 (hereinafter also referred to as "vehicle speed"), temperature sensor (not shown) that detects the ambient temperature of vehicle 1 (hereinafter also referred to as "outdoor temperature"), voltage sensor (not shown) that detects the output voltage of battery BAT, and current sensor (not shown) that detects the input and output current of battery BAT, etc.

[0045] like Figure 2 As shown, the drive unit 10 is located at the front of the vehicle body and is configured to include a motor (MOT), a power conversion unit (PCU), a transmission (TM), and an engine (ENG). On the other hand, the battery (BAT) is located at the rear of the vehicle body. In this way, by physically separating the battery (BAT) from the drive unit 10, which may generate heat during vehicle operation, it is possible to suppress the battery (BAT) from becoming overheated due to the heat from the drive unit 10.

[0046] The battery BAT has multiple energy storage units connected in series or parallel, and is configured to output a high voltage, such as 100 to 200 [V]. Lithium-ion batteries, nickel-metal hydride batteries, etc., can be used as the energy storage units of the battery BAT. In addition, a battery temperature sensor 15 is provided in the battery BAT to detect the temperature of the battery BAT (hereinafter also referred to as "battery temperature").

[0047] The motor MOT is an electric motor (so-called a "traction motor") that serves as the drive source for the drive wheels (i.e., the front wheels FW) of vehicle 1, such as an AC motor. In the motor MOT, power can be supplied from the battery BAT via the power conversion unit PCU (described later) and the high-voltage cable 20. In other words, the battery BAT supplies power to the motor MOT via the high-voltage cable 20 and the power conversion unit PCU.

[0048] The motor MOT converts the supplied electricity into power and outputs it. The power output from the motor MOT is transmitted to the drive wheels of vehicle 1 via the transmission TM (described later) to propel vehicle 1. Additionally, when vehicle 1 brakes, the motor MOT can regenerate power from the drive wheels of vehicle 1 to generate electricity. The electricity generated by the motor MOT is supplied to the battery BAT via the power conversion unit PCU and high-voltage cable 20 to charge the battery BAT.

[0049] The power conversion unit (PCU) performs the conversion of power received between the battery (BAT) and the motor (MOT). Specifically, the PCU converts the DC power supplied by the battery (BAT) into AC power and supplies it to the motor (MOT). This allows the appropriate power to be supplied to the motor (MOT).

[0050] Furthermore, the power conversion unit (PCU) converts the AC power supplied from the motor (MOT) into DC power and supplies it to the battery (BAT). This allows for the supply of appropriate power to the battery (BAT). Moreover, the PCU can also, as needed, convert the voltage of the power transmitted between the battery (BAT) and the motor (MOT) (i.e., boost or buck). The PCU is implemented, for example, through electronic circuitry including an inverter and a DC / DC converter.

[0051] like Figure 2 and Figure 3 As shown, one end of the high-voltage cable 20 is connected to the battery BAT, and the opposite end is connected to the power conversion device PCU, serving as a power line for supplying power from the battery BAT to the motor MOT, or for supplying power generated by the motor MOT to the battery BAT. The high-voltage cable 20 is, for example, a cable formed by covering and bundling multiple copper wires with an insulator such as heat-resistant polyvinyl chloride.

[0052] In this embodiment, the high-voltage cable 20 is arranged such that it passes under the floor panel 2, which forms the floor surface of the vehicle body, from the battery BAT located at the rear of the vehicle body and extends toward the drive unit 10 (i.e., motor MOT, power conversion device PCU) located at the front of the vehicle body. By routing the high-voltage cable 20 through the floor panel 2, it is possible to easily connect the battery BAT located at the rear of the vehicle body and the drive unit 10 located at the front of the vehicle body via the high-voltage cable 20.

[0053] Furthermore, the high-voltage cable 20 is installed along the exhaust system 30, which supplies exhaust gas from the engine ENG, as detailed later. This allows for the efficient use of the base plate passage 2a where the exhaust system 30 is installed to lay the high-voltage cable 20.

[0054] An engine (ENG) is an internal combustion engine such as a gasoline engine or diesel engine, which outputs power by burning supplied fuel. The power output from the engine (ENG) is transmitted, for example, via the transmission (TM) to the drive wheels (i.e., the front wheels (FW)) of the vehicle (1) to propel the vehicle (1). Alternatively, the power output from the engine (ENG) can also be transmitted to the motor (MOT) to generate electricity.

[0055] The transmission TM is a power transmission device disposed between the motor MOT and the engine ENG and the drive wheels (i.e., front wheels FW) of the vehicle 1. For example, it is a gear-type power transmission device that reduces the power output from the motor MOT or the engine ENG and transmits it to the drive wheels. Furthermore, the gear ratio in the transmission TM can be configured to be appropriately changed according to the instructions from the control device 50.

[0056] In addition, such as Figure 2 and Figure 3 As shown, an exhaust system 30 is connected to the engine ENG to discharge exhaust gas from the engine ENG to the outside. That is, exhaust gas from the engine ENG flows through the exhaust system 30.

[0057] The exhaust system 30 is arranged such that it passes under the floor 2 of the engine ENG located at the front of the vehicle body and extends toward the rear of the vehicle body. Specifically, as Figure 4 As shown, the exhaust system 30 is arranged within the floor passage 2a, which extends upwards from the bottom of the vehicle floor 2. Figure 4The high-voltage cable 20 is formed in a way that protrudes from the front of the vehicle body towards the rear (in the direction indicated by the "U"). Furthermore, the high-voltage cable 20, like the exhaust system 30, is housed within the floor channel 2a. More specifically, the high-voltage cable 20 and the exhaust system 30 are housed within the floor channel 2a in a left-right orientation of the vehicle 1, and are arranged to extend along the floor channel 2a in a front-rear orientation of the vehicle 1. By housing the high-voltage cable 20 and the exhaust system 30 within the floor channel 2a in this way, the minimum ground clearance of the vehicle 1 can be prevented from increasing, while ensuring sufficient clearance between the high-voltage cable 20 and the exhaust system 30 and the road surface.

[0058] like Figure 3 As shown, the exhaust system 30 is configured to include an exhaust manifold 31, a catalyst section 32, a main pipe 34, and a muffler 35. One end of the exhaust manifold 31 is connected to the engine ENG, and the opposite end is connected to the catalyst section 32. It is a pipe that sends the exhaust gas discharged from the cylinders of the engine ENG into the catalyst section 32. The exhaust manifold 31 is also referred to as the "front pipe".

[0059] The catalyst section 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 by the engine (ENG). A catalyst section temperature sensor 33 is installed in the catalyst section 32 to detect the temperature of the catalyst section 32 (hereinafter also referred to as "catalyst section temperature"). Furthermore, as... Figure 3 As shown, for example, the distance between the high-voltage cable 20 and the exhaust system 30 is closest near the catalyst section 32. Therefore, the high-voltage cable 20 is affected by heat from the catalyst section 32.

[0060] One end of the main pipe 34 is connected to the catalyst section 32, and the opposite end of the main pipe 34 is open to the outside. The main pipe 34 is a pipe that discharges the exhaust gas purified by the catalyst section 32 into the atmosphere. In addition, a silencer 35 is provided in the middle of the main pipe 34 to reduce the exhaust noise when the exhaust gas is released into the atmosphere.

[0061] Normally, the exhaust gas emitted from the engine is at a high temperature, so when the engine is running, the temperature of the exhaust system 30 will also increase.

[0062] [An example of control performed by a control device]

[0063] Next, an example of the control performed by the control device 50 will be described. The high-voltage cable 20 may heat up due to current flow. From the viewpoint of suppressing degradation and damage, it is undesirable for the high-voltage cable 20 to be in a high-temperature state. Therefore, the control device 50 has an energy-saving mode as a control mode that limits the output of the battery BAT, and switches to the energy-saving mode based on the battery temperature.

[0064] Here, the output of the battery BAT can be, for example, the amount of electricity output from the battery BAT per unit time. Furthermore, in the following description, the power flowing from the battery BAT to the motor MOT (i.e., the power that powers the motor MOT, hereinafter also referred to as "power operation side power") is considered the positive (+) direction, and the power flowing from the motor MOT to the battery BAT (i.e., the power that charges the battery BAT, hereinafter also referred to as "regenerative side power") is considered the negative (-) direction.

[0065] The higher the output of the battery BAT, that is, the greater the current flowing through the high-voltage cable 20 per unit time, the higher the battery temperature. Therefore, when the battery temperature reaches a certain level, it is assumed that the temperature of the high-voltage cable 20 (hereinafter also referred to as the "cable temperature") will also reach a certain level.

[0066] Therefore, when the battery temperature reaches or exceeds the predetermined energy-saving transition temperature, the control device 50 considers the cable temperature to be high enough and transitions to energy-saving mode. Thus, after the battery temperature reaches the energy-saving transition temperature, the output of the battery BAT can be limited, thereby reducing the current flowing through the high-voltage cable 20 per unit time. This reduces the heating of the high-voltage cable 20 caused by the current, thereby suppressing the temperature rise of the high-voltage cable 20.

[0067] Furthermore, the energy-saving transition temperature, which is a condition for switching to the energy-saving mode, is predetermined by the manufacturer of the vehicle 1 or the control device 50, taking into account factors such as the heat resistance of the high-voltage cable 20, and is set in the control device 50 accordingly. In this embodiment, the energy-saving transition temperature is set to X1 [°C].

[0068] For example, the control device 50 sets an upper limit value for the amount of electricity output from the battery BAT per unit time (hereinafter also referred to as the "battery output upper limit value"), and controls the motor MOT and the power conversion device PCU to ensure that the output of the battery BAT does not exceed the battery output upper limit value. Moreover, when the control device 50 is in energy-saving mode, it reduces the absolute value of the set battery output upper limit value compared to when it is not in energy-saving mode (i.e., in normal mode).

[0069] In this embodiment, the control device 50 sets the upper limit of the battery output related to the power on the power operation side to P11[kW] under normal conditions (where P11>0, for example, also refer to Figure 6 In energy-saving mode, it is set to P12[kW] (where P12 > P11, for example, refer to...). Figure 6 Additionally, the control device 50 sets the upper limit of the battery output related to the regenerative side power to -P21[kW] under normal conditions (where -P21 < 0, for example, also refer to...). Figure 6In energy-saving mode, it is set to -P22[kW] (where -P22 < -P21, for example, refer to...). Figure 6 ).

[0070] In this way, during energy-saving mode, the output of the battery BAT can be limited by reducing the absolute value of the upper limit of the battery output related to the power supply side and the regenerative side compared to normal mode. In addition, the aforementioned P11, P12, -P21, and -P22 are predetermined by the manufacturer of vehicle 1 or control device 50, taking into account the heat resistance of high-voltage cable 20, and are set in the control device 50.

[0071] On the other hand, the control device 50, based on the amount of accelerator pedal operation and vehicle speed of the vehicle 1, derives the driving force required to move the vehicle 1 (hereinafter referred to as the "required driving force"), and outputs power corresponding to the required driving force from the drive unit 10 (at least one of the motor MOT and the engine ENG). For example, if the power corresponding to the required driving force can be ensured by the motor MOT alone, the control device 50 moves the vehicle 1 by the motor MOT alone, and stops the engine ENG during this period. As a result, the fuel economy and NV (Noise, Vibration) performance of the vehicle 1 can be improved.

[0072] In vehicle 1, when in Eco mode, the output of the battery (BAT) is limited, thus reducing the upper limit of the power output of the motor (MOT). Therefore, if Eco mode is unnecessarily maintained for extended periods, the so-called "sluggishness" caused by the reduced upper limit of the motor's output power can lead to decreased driving performance, reduced fuel economy due to easy engine (ENG) operation, and decreased NVH performance, potentially diminishing the marketability of vehicle 1. Therefore, it is desirable to deactivate Eco mode at appropriate times.

[0073] Therefore, when the control device 50 is set to energy-saving mode, it deactivates the energy-saving mode when the battery temperature is lower than the energy-saving transfer temperature, and based on this configuration, the energy-saving deactivation temperature varies depending on the temperature of the exhaust system 30. Thus, in a vehicle 1 where power is supplied from the battery BAT to the motor MOT via a high-voltage cable 20 provided along the exhaust system 30 supplying exhaust gas from the engine ENG, the control device 50 can deactivate the energy-saving mode that restricts the output of the battery BAT at an appropriate time based on the temperature of the battery BAT.

[0074] The following is for reference Figure 5 and Figure 6 This section describes a specific example of the transition to and de-energization of the energy-saving mode performed by the control device 50. Figure 5This is a flowchart illustrating an example of the processing performed by the control device 50. For example, the control device 50 repeatedly performs this process at predetermined intervals during the period when the ignition power of the vehicle 1 is turned on. Figure 5 The series of processes shown.

[0075] Figure 6 The above figure (a) shows the relationship between battery temperature and the activation (transfer) / deactivation (cancellation) of the power-saving mode. Figure 6 Figure (b) below shows the relationship between the power-saving mode being on / off and the upper limit of battery output. Furthermore, in Figure 6 In the diagram, the solid line represents an example where the energy-saving mode is deactivated by performing steps S15 and S16, which will be described later. On the other hand, in... Figure 6 In the text, a single-dotted line indicates an example where the energy-saving mode is deactivated by performing the processes described later in steps S17 and S16.

[0076] [An example of processing performed by a control device]

[0077] like Figure 5 As shown, the control device 50 first determines whether to set the control mode related to the output control of the battery BAT to energy-saving mode (step S11). If it is set to energy-saving mode (step S11: yes), the control device 50 directly proceeds to the processing in step S14.

[0078] On the other hand, if the power-saving mode is not set (step S11: No), the control device 50 determines whether the battery temperature detected by the battery temperature sensor 15 has reached or exceeded X1 [°C], which is determined as the power-saving transition temperature (step S12). If the battery temperature is less than X1 [°C] (step S12: No), the control device 50 terminates. Figure 5 The series of processes shown.

[0079] On the other hand, if the battery temperature reaches X1 [°C] or higher (step S12: Yes), the control device 50 switches to energy-saving mode (step S13). Thus, the control device 50, for example, Figure 6 As shown in period T1 of (a), the battery transitions to energy-saving mode when the battery temperature rises and reaches X1 [°C]. Therefore, as Figure 6 As shown in (b), the upper limit of battery output related to power on the power operation side was P11 [kW] before period T1, and became P12 [kW] from period T1 onwards. In addition, the upper limit of battery output related to power on the regenerative side was -P21 [kW] before period T1, and became -P22 [kW] from period T1 onwards.

[0080] Thus, starting from period T1, the upper limit of the battery output related to the power on the power operation side and the power on the regeneration side decreases, thereby reducing the upper limit of the power output of the motor MOT and the upper limit of the power generation that the motor MOT can generate per unit time.

[0081] Furthermore, when the battery temperature reaches X1 [°C], T1 transitions to energy-saving mode, thus, as Figure 6 As shown in (a), the battery temperature gradually decreases after period T1. Additionally, although the diagram is omitted, the cable temperature also gradually decreases after period T1, similar to the battery temperature.

[0082] Next, the control device 50 determines whether the catalyst temperature detected by the catalyst temperature sensor 33 is above a predetermined Xa [°C] (where Xa > 0) (step S14). Xa, for example, is a temperature set by the manufacturer of the vehicle 1 or the manufacturer of the control device 50, as a condition for determining that the exhaust system 30 including the catalyst 32 is in a high-temperature state.

[0083] When the catalyst section temperature is above Xa [°C] (step S14: Yes), the control device 50 determines whether the battery temperature detected by the battery temperature sensor 15 is below the predetermined X2 [°C] (where X2 < X1) (step S15). X2, for example, is the energy-saving release temperature when the catalyst section temperature is above Xa [°C], i.e., when the exhaust system 30, including the catalyst section 32, is in a high-temperature state; this temperature is preset by the manufacturer of the vehicle 1 or the control device 50.

[0084] Then, if the battery temperature is not lower than X2 [°C] (step S15: No), the control device 50 ends. Figure 5 The series of processes shown. On the other hand, if the battery temperature is less than X2 [°C] (step S15: Yes), the control device 50 deactivates the energy-saving mode (step S16) and ends. Figure 5 The series of processes shown.

[0085] As described above, an example of deactivating the energy-saving mode by performing steps S15 and S16 is shown in... Figure 6 The solid line represents the middle. That is, in this case, such as Figure 6 As shown in period T2 of (a), when the battery temperature decreases and reaches X2 [°C], the control device 50 deactivates the energy-saving mode. Therefore, as... Figure 6 As shown in (b), the upper limit of battery output related to power supply on the power operation side returns to P11 [kW] from period T2. In addition, the upper limit of battery output related to regenerative power supply also returns to -P21 [kW] from period T1.

[0086] Thus, when the catalyst temperature is above Xa [°C], the energy-saving mode is deactivated at the time T2 when the battery temperature reaches X2 [°C]. Figure 6 As shown by the solid line in (a), the battery temperature can gradually increase after period T2. Additionally, although the illustration is omitted, in this case, the cable temperature can also gradually increase after period T2, similar to the battery temperature.

[0087] On the other hand, if the catalyst section temperature is less than Xa [°C] (step S14: No), the control device 50 determines whether the battery temperature detected by the battery temperature sensor 15 is less than the predetermined X3 [°C] (where X2 < X3 < X1) (step S17). Here, X3 is, for example, the energy-saving release temperature when the catalyst section temperature is less than Xa [°C], that is, when the exhaust system 30 including the catalyst section 32 is not in a high-temperature state (in other words, in a non-high-temperature state), and is the temperature set by the vehicle 1 or the manufacturer of the control device 50, etc.

[0088] Then, if the battery temperature is not lower than X3 [°C] (step S17: No), the control device 50 ends. Figure 5 The series of processes shown. On the other hand, if the battery temperature is less than X3 [°C] (step S17: Yes), the control device 50 enters the process of step S16 to deactivate the energy-saving mode and end the process. Figure 5 The series of processes shown.

[0089] As described above, an example of deactivating the energy-saving mode by performing steps S17 and S16 is shown below. Figure 6 In this case, a single-dotted line is used to represent it. That is, in this case, such as... Figure 6 As shown in period T3 of (a), when the battery temperature decreases and reaches X3 [°C], the control device 50 deactivates the energy-saving mode. X3 [°C] is a temperature higher than X2 [°C], therefore, in this case, the energy-saving mode is deactivated in period T3, which is earlier than period T2. Thus, in this case, as Figure 6 As shown in (b), the upper limit of battery output related to power supply on the power operation side returns to P11 [kW] from period T3, which is earlier than period T2. The upper limit of battery output related to regenerative power supply also returns to -P21 [kW] from period T3, which is earlier than period T2.

[0090] Thus, when the catalyst temperature is below Xa [°C], the energy-saving mode is deactivated at the time T3 when the battery temperature reaches X3 [°C]. Figure 6 As shown by the dashed line in (a), the battery temperature can gradually increase after period T3. Additionally, although the illustration is omitted, in this case, the cable temperature can also gradually increase after period T3, similar to the battery temperature.

[0091] As explained above, in vehicle 1, the battery BAT and drive unit 10 can be easily connected via the high-voltage cable 20 by providing a high-voltage cable 20 along the exhaust system 30. Thus, with the high-voltage cable 20 provided along the exhaust system 30, the high-voltage cable 20 is affected by heat from the exhaust system 30. Therefore, it is conceivable that even if the battery temperature is low to a certain level (e.g., below X3 [°C] but above X2 [°C]), the cable temperature will also be high to a certain level due to the heat from the exhaust system 30.

[0092] Therefore, in the control device 50, the energy-saving mode is deactivated when the battery temperature is below the energy-saving deactivation temperature, and based on this configuration, the energy-saving deactivation temperature varies depending on the temperature of the exhaust system 30 (e.g., the catalyst section temperature). Thus, even when the high-voltage cable 20 is installed along the exhaust system 30, the energy-saving mode can be deactivated based on the battery temperature at an appropriate time, taking into account the temperature of the exhaust system 30.

[0093] More specifically, in this embodiment, when the exhaust system 30 is at a high temperature (e.g., the catalyst temperature is above Xa [°C]), the energy-saving deactivation temperature is lower compared to when the exhaust system 30 is not at a high temperature (e.g., the catalyst temperature is below Xa [°C]). Therefore, even if the battery temperature becomes low enough, the cable temperature could still become high due to the heat from the exhaust system 30, allowing the energy-saving mode to continue without deactivation. Thus, it is possible to suppress the situation where the energy-saving mode is deactivated despite the cable temperature becoming high, causing the high-voltage cable 20 to become high-temperature. On the other hand, when the exhaust system 30 is not at a high temperature, it is conceivable that if the battery temperature becomes low enough, the cable temperature would also become low enough. Therefore, by increasing the energy-saving deactivation temperature, the energy-saving mode can be deactivated earlier, increasing the opportunity to effectively utilize the output performance inherent in the battery (BAT), thereby improving the commercial viability of the vehicle 1.

[0094] Furthermore, a battery temperature sensor 15 is typically installed in the battery pack (BAT) of an electric vehicle such as vehicle 1 to detect battery temperature. Therefore, the control device 50 switches between and cancels the energy-saving mode based on the battery temperature detected by the battery temperature sensor 15. Thus, even without installing a temperature sensor for detecting cable temperature on the high-voltage cable 20, or without the control device 50 performing calculations to estimate the cable temperature, the switching between and canceling the energy-saving mode can be performed. Therefore, the complexity of the vehicle 1's configuration can be reduced, or the processing burden on the control device 50 can be decreased, while simultaneously enabling the switching between and canceling the energy-saving mode.

[0095] Furthermore, in vehicles like vehicle 1 that are equipped with an engine (ENG, internal combustion engine), the catalyst section 32 of the exhaust system 30 is typically equipped with a catalyst section temperature sensor 33 for detecting the catalyst section temperature. Therefore, the control device 50 uses the catalyst section temperature detected by the catalyst section temperature sensor 33 as the temperature of the exhaust system 30. As a result, it is not necessary to add a temperature sensor other than the catalyst section temperature sensor 33 to the exhaust system 30 in order to obtain the temperature of the exhaust system 30, thus reducing the complexity of the vehicle 1's configuration.

[0096] [Variation Example]

[0097] Next, variations of the above embodiments will be described. Furthermore, the same reference numerals will be used for the parts corresponding to the embodiments described above, and their descriptions will be omitted or simplified as appropriate.

[0098] In the above embodiment, the catalyst temperature detected by the catalyst temperature sensor 33 is used as the temperature of the exhaust system 30, and the energy-saving deactivation temperature varies depending on the catalyst temperature. In contrast, in the variation described below, an evaluation value, i.e., a setting temperature, for setting the energy-saving deactivation temperature is derived based on at least one of the ambient temperature (i.e., external temperature) and the vehicle speed (i.e., vehicle speed) around the vehicle 1, and the temperature of the exhaust system 30 (e.g., catalyst temperature), and the energy-saving deactivation temperature varies depending on the derived setting temperature. Therefore, it is possible to deactivate the energy-saving mode based on the battery temperature at a more appropriate time, considering at least one of the vehicle's external temperature and vehicle speed, in addition to the exhaust system 30 temperature.

[0099] [An example of processing performed by a control device in a modified version]

[0100] Figure 7 This is a flowchart illustrating an example of the processing performed by the control device 50 in a modified example. The control device 50 in the modified example is, for example, as shown below. Figure 7 As shown, instead Figure 5 The process in step S14 of the flowchart shown is followed by the processes in steps S21 and S22.

[0101] In step S21, the control device 50 derives a set temperature for setting the energy-saving release temperature based on the catalyst section temperature (an example of the exhaust system 30 temperature), the external air temperature of the vehicle 1, and the vehicle speed (step S21). That is, the high-voltage cable 20 is affected not only by the heat from the exhaust system 30 but also by the external air temperature of the vehicle 1 and the driving wind. For example, when the external air temperature of the vehicle 1 is low, the temperature rise of the high-voltage cable 20 can be suppressed compared to when the external air temperature is high. Similarly, when the vehicle speed of the vehicle 1 is high, the driving wind in contact with the high-voltage cable 20 per unit time increases compared to when the vehicle speed is low, thus suppressing the temperature rise of the high-voltage cable 20.

[0102] Therefore, the control device 50 derives a set temperature that takes into account the effects of these factors on the cable temperature, based on the catalyst section temperature, the external air temperature of the vehicle 1, and the vehicle speed. Furthermore, the set temperature can be derived from a map pre-stored in the storage device of the control device 50, or from a defined formula that includes the catalyst section temperature, the external air temperature of the vehicle 1, and the vehicle speed as parameters.

[0103] After the control device 50 derives the set temperature through the processing in step S21, it determines whether the derived set temperature is the specified Xb[°C] (where Xb>0) (step S22). Herein, Xb is, for example, the temperature set by the manufacturer of the vehicle 1 or the control device 50 for the control device 50.

[0104] Then, if the set temperature is Xb [°C] or higher (step S22: Yes), the control device 50 proceeds to step S15. On the other hand, if the set temperature is less than Xb [°C] (step S22: No), the control device 50 proceeds to step S17.

[0105] As explained above, the high-voltage cable 20 is affected not only by the heat from the exhaust system 30, but also by the external temperature and wind conditions of the vehicle 1. Therefore, the control device 50 in the modified example derives a setting temperature for setting the energy-saving deactivation temperature based on the temperature of the exhaust system 30 (e.g., catalyst section temperature), and at least one of the external temperature and vehicle speed of the vehicle 1, and uses the derived setting temperature to set the energy-saving deactivation temperature. Thus, the energy-saving mode can be deactivated based on the battery temperature at a more appropriate time, taking into account at least one of the external temperature and vehicle speed of the vehicle 1, in addition to the temperature of the exhaust system 30.

[0106] The various embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that those skilled in the art will conceive of various modifications or alterations within the scope of the claims, and it is understood that these modifications or alterations also fall within the technical scope of the present invention. Furthermore, the constituent elements of the foregoing embodiments can be arbitrarily combined without departing from the spirit of the invention.

[0107] For example, in step S21 of the aforementioned modified example, the set temperature is derived based on the catalyst section temperature, the external air temperature of vehicle 1, and the vehicle speed, but it is not limited to this. For example, in addition to the temperature of the exhaust system 30 (e.g., catalyst section temperature), the external air temperature of vehicle 1, and the vehicle speed, the operating state of the engine ENG (e.g., engine speed) can also be considered to derive the set temperature. That is, when the engine ENG is under high load, it is assumed that the temperature of the exhaust gas discharged from the engine ENG is also higher, so a higher set temperature can be derived accordingly. As a result, the energy-saving mode can be deactivated based on the battery temperature at a more appropriate time.

[0108] At least the following items are described in this specification, etc. The components corresponding to the above embodiments are shown in parentheses, but the scope is not limited thereto.

[0109] (1) A vehicle (vehicle 1) comprising: an internal combustion engine (engine ENG); an exhaust system (exhaust system 30) for supplying exhaust gas flow from the internal combustion engine; an electric motor (motor MOT) as a drive source for driving drive wheels (front wheels FW); a battery (battery BAT) for supplying power to the electric motor via a cable (high-voltage cable 20) disposed along the exhaust system; and a control device (control device 50), wherein,

[0110] The control device performs the following control:

[0111] When the battery temperature reaches or exceeds a predetermined energy-saving transition temperature (X1 [°C]), an energy-saving mode is set to limit the battery output.

[0112] When the energy-saving mode is set, if the battery temperature is lower than the energy-saving deactivation temperature (X2 [°C], X3 [°C]), which is lower than the energy-saving transfer temperature, the energy-saving mode is deactivated, and

[0113] The energy-saving release temperature varies depending on the temperature of the exhaust system.

[0114] According to (1), by setting a cable along the exhaust system to supply power from the battery to the motor, the battery and motor can be easily connected via the cable. However, when the cable is set along the exhaust system, it is subject to heat from the exhaust system. Therefore, it is conceivable that even if the battery temperature is low enough, the cable temperature could be high enough due to the heat from the exhaust system. Therefore, the control device deactivates the energy-saving mode based on the condition that the battery temperature is below the energy-saving deactivation temperature, and with this configuration, the energy-saving deactivation temperature varies depending on the exhaust system temperature. Thus, even when the cable along the exhaust system supplies power from the battery to the motor, the energy-saving mode can be deactivated based on the battery temperature at an appropriate time, taking into account the exhaust system temperature.

[0115] (2) The vehicle according to (1), wherein,

[0116] The exhaust system is arranged such that it passes under the vehicle body from the internal combustion engine located at the front of the vehicle body and extends toward the rear of the vehicle body.

[0117] The cable is arranged such that it passes under the battery located at the rear of the vehicle body and extends toward the motor located at the front of the vehicle body.

[0118] According to (2), the battery located at the rear of the vehicle body and the electric motor located at the front of the vehicle body can be easily connected via a cable.

[0119] (3) The vehicle according to (1) or (2), wherein,

[0120] The vehicle also includes a power conversion unit (PCU) that performs the conversion of power received between the battery and the electric motor.

[0121] One end of the cable is connected to the battery, and the other end of the cable is connected to the power conversion device.

[0122] The battery supplies power to the motor via the cable and the power conversion device.

[0123] According to (3), it is possible to supply appropriate power to the motor.

[0124] (4) The vehicle according to any one of (1) to (3), wherein,

[0125] When the temperature of the exhaust system is above a specified value, the control device reduces the energy-saving release temperature compared to when the temperature of the exhaust system is below the specified value.

[0126] When the temperature of the exhaust system is above a specified value (i.e., when the exhaust system is in a high-temperature state), it is conceivable that even if the battery temperature becomes low to a certain level, the cable temperature will become high to a certain level due to the heat from the exhaust system. According to (4), when the temperature of the exhaust system is above a specified value, compared with the case where the temperature of the exhaust system is below a specified value, by lowering the energy-saving deactivation temperature, this situation can be suppressed: although the cable temperature becomes high to a certain level due to the heat from the exhaust system, the energy-saving mode is deactivated, causing the cable to become in a high-temperature state.

[0127] (5) The vehicle according to any one of (1) to (4), wherein,

[0128] The exhaust system is configured to include a catalyst section (catalyst section 32) equipped with a temperature sensor (catalyst section temperature sensor 33).

[0129] The temperature of the exhaust system is the temperature of the catalyst section detected by the temperature sensor.

[0130] Typically, the catalyst section of the exhaust system is equipped with a temperature sensor. According to (5), the temperature of the catalyst section detected by the temperature sensor of the catalyst section is used as the temperature of the exhaust system. Therefore, it is not necessary to add a new temperature sensor in order to obtain the temperature of the exhaust system, which can reduce the complexity of the vehicle structure.

[0131] (6) The vehicle according to any one of (1) to (5), wherein,

[0132] The control device performs the following control:

[0133] Based on at least one of the ambient temperature around the vehicle and the vehicle's speed, as well as the temperature of the exhaust system, a set temperature for setting the energy-saving release temperature is derived.

[0134] The energy-saving release temperature varies depending on the set temperature.

[0135] According to (6), the energy-saving mode can be deactivated based on battery temperature at a more appropriate time, taking into account at least one of the ambient temperature of the vehicle and the vehicle's driving speed, in addition to the temperature of the exhaust system.

Claims

1. A vehicle comprising: an internal combustion engine; an exhaust system for supplying exhaust gas flow from the internal combustion engine; an electric motor as a drive source for driving drive wheels; a battery supplying power to the electric motor via a cable disposed along the exhaust system; and a control device, wherein... The control device performs the following control: When the battery temperature reaches or exceeds a predetermined energy-saving transition temperature, an energy-saving mode is established that limits the battery's output. When the energy-saving mode is set, if the battery temperature is lower than the energy-saving deactivation temperature (which is lower than the energy-saving transfer temperature), the energy-saving mode is deactivated, and The energy-saving release temperature varies depending on the temperature of the exhaust system. When the temperature of the exhaust system is above a predetermined value, the energy-saving release temperature is reduced compared to when the temperature of the exhaust system is below the predetermined value.

2. The vehicle according to claim 1, wherein, The exhaust system is arranged such that it passes under the vehicle body from the internal combustion engine located at the front of the vehicle body and extends toward the rear of the vehicle body. The cable is arranged such that it passes under the battery located at the rear of the vehicle body and extends toward the motor located at the front of the vehicle body.

3. The vehicle according to claim 1 or 2, wherein, The vehicle also includes a power conversion device that converts the power received between the battery and the electric motor. One end of the cable is connected to the battery, and the other end of the cable is connected to the power conversion device. The battery supplies power to the motor via the cable and the power conversion device.

4. The vehicle according to claim 1 or 2, wherein, The exhaust system is configured to include a catalyst section equipped with a temperature sensor. The temperature of the exhaust system is the temperature of the catalyst section detected by the temperature sensor.

5. The vehicle according to claim 1 or 2, wherein, The control device performs the following control: Based on at least one of the ambient temperature around the vehicle and the vehicle's speed, as well as the temperature of the exhaust system, a set temperature for setting the energy-saving release temperature is derived. The energy-saving release temperature varies depending on the set temperature.

6. The vehicle according to claim 3, wherein, The exhaust system is configured to include a catalyst section equipped with a temperature sensor. The temperature of the exhaust system is the temperature of the catalyst section detected by the temperature sensor.

7. The vehicle according to claim 3, wherein, The control device performs the following control: Based on at least one of the ambient temperature around the vehicle and the vehicle's speed, as well as the temperature of the exhaust system, a set temperature for setting the energy-saving release temperature is derived. The energy-saving release temperature varies depending on the set temperature.

8. The vehicle according to claim 6, wherein, The control device performs the following control: Based on at least one of the ambient temperature around the vehicle and the vehicle's speed, as well as the temperature of the exhaust system, a set temperature for setting the energy-saving release temperature is derived. The energy-saving release temperature varies depending on the set temperature.

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