Hybrid vehicles

Abstract

To provide a hybrid vehicle that does not require the engine to continue running after stopping, even in places where long-term parking is expected, thus avoiding unnecessary engine operation. [Solution] A hybrid vehicle comprising an engine, a battery, a generator for charging the battery, a catalyst for purifying the exhaust gas of the engine, a heating device for heating the catalyst using the power of the battery, and a processor for controlling the drive of the generator, wherein the processor controls the drive of the generator so that the charge level of the battery reaches a predetermined threshold or higher by the time of arrival at a destination where parking for a predetermined time or longer is expected, and the threshold is a charge level that can supply the power necessary to heat the catalyst, which has cooled due to parking for the predetermined time or longer, using the heating device.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to hybrid vehicles.

BACKGROUND ART

[0002] Vehicles that travel by engine drive are provided with catalysts that purify exhaust gas. In the case of diesel engines, an exhaust gas purification device (DPD: Diesel Particulate Diffuser) that collects, burns and removes soot in exhaust gas in the middle of the exhaust pipe, and a selective catalytic reduction denitration device (SCR: Selective Catalytic Reduction) that decomposes nitrogen oxides in exhaust gas are provided. The DPD includes a diesel oxidation catalyst (DOC: Diesel Oxidation Catalyst) and a soot collection filter (DPF: Diesel Particulate Filter), and the SCR includes a nitrogen oxide reduction catalyst (SCR catalyst), an ammonia slip catalyst (ASC: Ammonia Slip Catalyst) and a urea injector.

[0003] Since the diesel oxidation catalyst and the nitrogen oxide reduction catalyst become active at or above a predetermined temperature (activation start temperature), a heating device for heating the catalyst is provided in the vehicle, and the catalyst is heated when the catalyst is cold, such as at engine startup. In the case of a hybrid vehicle, electric power may be supplied to the heating device from a battery that supplies electric power to the drive motor.

[0004] When the engine is started after long-time parking, the temperature of the catalyst has decreased, so it is necessary to warm the catalyst to the activation start temperature by the heating device. For this reason, there is a technique of charging the battery before parking so as to secure the electric power required for heating the catalyst so as not to cause electric power shortage at engine startup (Patent Document 1). In this technique, when the state of charge of the battery is below a predetermined threshold value at the time of parking, the engine is driven to generate electric power to charge the battery before the engine is stopped.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-166400 [Overview of the project] [Problems that the invention aims to solve]

[0006] In the conventional technology described above, the battery charge level is measured when parking, that is, when the vehicle is stopped in a parking space and the engine and motor are stopped, and charging is performed as needed. This requires the engine to be driven to generate electricity while the vehicle is stopped in the parking space, which takes time until the engine is stopped and has the problem of continuing to emit exhaust gases while the vehicle is stopped, even in places where idling is undesirable, such as public parking lots. Furthermore, even in cases of short-term parking where the catalytic converter has not cooled down sufficiently and there is no need to heat the catalytic converter when starting the engine, the engine may continue to run in order to charge the battery, which can lead to a decrease in fuel efficiency.

[0007] This disclosure aims to provide a hybrid vehicle that does not require the engine to continue running to charge the battery after stopping, and does not require charging when short-term parking does not require securing the power necessary to heat the catalyst. [Means for solving the problem]

[0008] The hybrid vehicle of this disclosure includes an engine, a battery, a generator for charging the battery, a catalyst for purifying exhaust gases from the engine, a heating device for heating the catalyst using the power from the battery, and a processor for controlling the operation of the generator, wherein the processor controls the operation of the generator so that the charge level of the battery reaches a predetermined threshold by the time of arrival at a destination where parking for a predetermined time or longer is expected, and the threshold is a charge level that can supply the power necessary to heat the catalyst, which has cooled due to parking for the predetermined time or longer, using the heating device. [Effects of the Invention]

[0009] When long-term parking is expected, the battery is charged during the drive before arriving at the destination, ensuring that the necessary charge is available to heat the catalyst with the heating device before arrival, eliminating the need to continue engine operation after stopping. This prevents the engine from continuing to run against the driver's will in environments where idling is undesirable, such as public parking lots. Furthermore, for short-term parking where heating the catalyst is not necessary upon restarting after parking, the battery is not charged to heat the catalyst with the heating device, thus avoiding unnecessary charging, improving fuel efficiency, and preventing battery degradation. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram showing the configuration of a hybrid vehicle. [Figure 2] This diagram shows the configuration of the engine's exhaust system. [Figure 3] This diagram shows an overview of how a hybrid vehicle operates. [Figure 4] This is a flowchart for battery charging control. [Figure 5] This graph shows the time evolution of each parameter. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are all specific examples of this disclosure. Therefore, the components, their arrangement and connection configurations shown in the following embodiments are examples and are not intended to limit this disclosure. Furthermore, the figures are schematic diagrams and not necessarily strictly accurate. In the figures, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

[0012] Figure 1 shows the configuration of hybrid vehicle 1. Hybrid vehicle 1 has a drive engine 7 and a motor 9. The motor 9 is driven by power supplied from a battery 4. The battery 4 is charged by power supplied from a generator 8. The generator 8 is driven by the engine 7. The battery 4 may also be charged by regenerative energy generated by the motor 9 during deceleration.

[0013] The hybrid vehicle 1 has a navigation system 10. The navigation system 10 provides route guidance to a set destination. When the user enters a destination into the navigation system 10, it calculates the route to the destination from the vehicle's position acquired by the position sensor 6 and map data, and displays it on the display 11 to provide directions.

[0014] The hybrid vehicle 1 has a control device 3 that controls the operation of the engine 7, generator 8, motor 9, and heating device 5, and also controls the charging of the battery 4.

[0015] The control device 3 includes a processor 31 such as a CPU (Central Processing Unit) as an arithmetic unit, a memory 32 such as a non-volatile memory like a ROM (Read Only Memory) or a volatile memory like a RAM (Random Access Memory) as a main memory, a storage device 33 such as an HDD (Hard Disk Drive) or SSD (Solid State Drive) as an auxiliary storage device, and an interface 34 as an input / output circuit, all connected via a bus 35. The processor 31 controls the operation of the engine 7, generator 8, motor 9, and heating device 5, and also controls the charging of the battery 4, while temporarily storing data in the memory 32 according to the control program stored in the storage device 33.

[0016] The catalyst 72 and heating device 5 of the hybrid vehicle 1 will be described with reference to Figure 2. Figure 2 is a schematic diagram of the catalyst 72 and heating device 5. Exhaust gas emitted from the engine 7 is released outside the vehicle through the exhaust pipe 71. A catalyst 72 for purifying the exhaust gas is installed in the exhaust pipe 71. The catalyst 72 is, for example, a diesel oxidation catalyst or a nitrogen oxide reduction catalyst. A heating device 5 is provided for the catalyst 72.

[0017] In the case of a diesel engine, the catalyst 72 is a catalyst in an exhaust gas purification system that includes an exhaust gas purification device (DPD: Diesel Particulate Diffuser) located in the middle of the exhaust pipe 71 for collecting and burning soot from the exhaust gas, and a selective catalytic reduction denitrification (SCR: Selective Catalytic Reduction) device for decomposing nitrogen oxides in the exhaust gas. The DPD has a diesel oxidation catalyst (DOC: Diesel Oxidation Catalyst) and a soot collection filter (DPF: Diesel Particulate Filter), while the SCR has a nitrogen oxide reduction catalyst (SCR catalyst), an ammonia slip catalyst (ASC: Ammonia Slip Catalyst), and a urea injector. The catalyst 72 is also equipped with a temperature sensor 73 for detecting the temperature of the catalyst 72.

[0018] The heating device 5 may be a heater installed inside the exhaust pipe 71 that heats the exhaust gas and uses the heated exhaust gas to heat the catalyst 72, or it may be a heater installed adjacent to the catalyst 72 that heats the catalyst 72. Alternatively, it may be an electrocatalyst that heats the carrier on which the catalyst 72 is supported by passing an electric current through it.

[0019] Power is supplied to the heating device 5 from the battery 4. The battery 4 supplies power to the drive motor 9, but may be an auxiliary battery provided separately from the drive battery. The battery 4 is charged with electric power generated by the generator 8. The control device 3 drives the engine 7 and the generator 8 to charge the battery 4. Further, the control device 3 supplies the electric power of the battery 4 to the heating device 5 to generate heat and heat the catalyst 72. The control device 3 may heat the catalyst 72 by controlling the heating device 5 based on the temperature of the catalyst 72 detected by the temperature sensor 73.

[0020] An outline of the operation of the hybrid vehicle 1 of the present disclosure will be described with reference to FIG. 3. FIG. 3 schematically shows a state where the hybrid vehicle 1 is traveling toward a destination 2. The hybrid vehicle 1 travels toward the destination 2 where long-time parking is expected. The destination where long-time parking is expected is, for example, a parking lot at a business office of a transport vehicle, a parking lot at the home of a private car, or the like, and refers to a parking lot or the like where it is expected that the catalyst warmed during traveling will drop to a predetermined temperature or lower when the engine is stopped for parking. Here, the predetermined temperature is desirably set to an activation start temperature.

[0021] The hybrid vehicle 1 travels along the travel route indicated by the navigation device 10 toward the destination 2 while grasping the own vehicle position by communicating with the GPS satellite S. When the distance L to the destination 2 approaches L1, the control device 3 of the hybrid vehicle 1 acquires the state of charge of the battery 4, and the control device 3 controls the engine 7 and the generator 8 to charge the battery 4 so that the state of charge exceeds the threshold value P1 at the time when the hybrid vehicle 1 arrives at the destination 2. A charging area A may be defined in advance around the destination 2, and the battery 4 may be charged when the hybrid vehicle 1 enters the charging area A. This enables appropriate charging without calculating the distance from the current position to the destination.

[0022] The threshold P1 is a value that indicates a sufficient charge state for the hybrid vehicle 1 to heat the cooled catalyst 72 with the heating device 5 after being parked for a long period of time. The threshold P1 is set as a charge state that ensures the hybrid vehicle 1 has enough charge to run and further heat the catalyst 72. The threshold P1 may be set to different values ​​depending on the outside temperature acquired by the temperature sensor 12, for example. The threshold P1 may also be set according to the weather forecast or season. That is, when the outside temperature is low, or when the weather forecast or season is winter and the outside temperature is expected to be low, the temperature of the catalyst 72 will be lower, so the threshold P1 may be set higher than when the outside temperature is high. This ensures that an appropriate amount of charge is always secured regardless of the outside temperature.

[0023] The processes performed by the control device 3 of the hybrid vehicle 1 of this disclosure will be explained according to the flowchart shown in Figure 4. The flowchart shown in Figure 4 represents a series of processes in which the processor 31 of the control device 3 controls the charging of the battery 4 of the hybrid vehicle 1 according to the control program. First, the processor 31 acquires the location information of the hybrid vehicle 1 detected by the position sensor 6 (step S1). The location information is acquired, for example, by the position sensor 6 receiving a signal from a GPS satellite S.

[0024] The processor 31 determines, based on the acquired location information, whether the hybrid vehicle 1 has approached within a predetermined distance L1 of the destination 2 (step S2). The destination 2 is a place where long-term parking is expected, and where the catalyst 72 is expected to cool down due to long-term parking, requiring the heating device 5 to heat the catalyst 72 at startup. The destination 2 may be a destination set in the navigation device 10, or it may be a place that the user has pre-set and stored in the storage 33 as a place where long-term parking is expected. The navigation device 10 may also store driving records including past parking locations and parking times, and acquire parking locations where the parking time is longer than a predetermined parking time as the destination 2. The distance to the destination 2 may be calculated by determining the straight-line distance between the current location and the destination 2, or it may be calculated by determining the distance along the driving route from the current location to the destination 2 based on the map information and driving route information held by the navigation device 10.

[0025] The predetermined distance L1 is set as a distance that allows the hybrid vehicle 1 to charge the battery 4 while traveling the predetermined distance L1, thereby securing the power necessary to heat the cooled catalyst 72 with the heating device 5. The predetermined distance L1 is determined as a distance sufficient to charge the battery 4 to a threshold P1 during driving, for example, 3 km, and is determined considering the capacity of the battery 4, the power consumption of the heating device 5, the capacity of the generator 8, the amount of regenerative energy predicted by downhill slopes, the outside temperature, etc.

[0026] If the distance to destination 2 is not within a predetermined distance L1 (if step S2 is No), the processor 31 continues to acquire location information (returning to step S1) and continues monitoring until the distance to destination 2 approaches L1.

[0027] On the other hand, when the distance to destination 2 approaches within a predetermined distance L1 (if step S2 is Yes), the processor 31 determines whether the State of Charge (SOC), which indicates the charge state of the battery 4, is less than the threshold P1 (step S3). The threshold P1 is set as a charge state that is sufficient for the hybrid vehicle 1 to heat the cooled catalyst 72 with the heating device 5 after being parked for a long time, and that ensures the amount of charge necessary for the hybrid vehicle 1 to run, i.e., the amount of charge that allows it to run until the catalyst is fully heated, and further heating of the catalyst 72 is possible. Specifically, it is determined by considering the activation temperature of the catalyst and the ambient temperature. After heating is complete, the engine output can be increased to charge the battery, thus avoiding deterioration of exhaust gases. The threshold P1 may be set to different values ​​depending on the ambient temperature, for example. If the SOC is greater than or equal to the threshold P1 (if step S3 is No), there is no need to increase the SOC any further, so the system proceeds to the SOC maintenance control in step S7, which will be described later.

[0028] On the other hand, if the SOC is less than the threshold P1 (if step S3 is Yes), the processor 31 starts charging control (step S4). Here, charging control is a control that increases the SOC of the battery 4 through driving, for example, by increasing the output of the engine 7 to drive the generator 8 with the surplus output not used for driving to charge the battery 4, and at the same time reducing the output of the motor 9 to reduce power consumption.

[0029] After starting charge control, the processor 31 determines whether the SOC of the battery 4 has become equal to or greater than the threshold P1 (step S5). If the SOC remains below the threshold P1 (step S5 is No), the processor 31 continues charge control until the SOC becomes equal to or greater than the threshold P1.

[0030] Then, if the SOC of battery 4 exceeds the threshold P1 (if step S5 is Yes), the processor 31 stops charging control (step S6).

[0031] When the SOC is secured to be above the threshold P1, the processor 31 starts SOC maintenance control (step S7). Here, SOC maintenance control is a control that maintains the SOC at its current level through driving. For example, it maintains the SOC level by setting the output of the engine 7 to a moderate level and the output of the motor 9 powered by the battery 4 to a moderate level, and making the amount of charge generated by the output of the engine 7 equal to the amount of power consumed by the motor 9 powered by the battery 4.

[0032] The processor 31 determines whether the hybrid vehicle 1 has arrived at destination 2 (step S8). If it has not arrived at destination 2 (step S8 is No), it continues SOC maintenance control. If it has arrived at destination 2 (step S8 is Yes), it terminates the process.

[0033] Figure 5 is a graph showing the time changes in the distance to destination 2 (L), state of charge (SOC), engine output (average) (Pe), and motor output (average) (Pm) as the hybrid vehicle 1 approaches destination 2 under the control of the control device 3. The graph progresses from left to right, with the vertical axis representing the values ​​of each graph.

[0034] At time t=t0, in graph g1, hybrid vehicle 1 is traveling towards destination 2 at a position where the distance L to destination 2 exceeds a predetermined distance L1. At this time, in graph g2, the charge state (SOC) is slightly below the threshold P1, but is sufficient for normal driving. Because the charge state (SOC) is sufficient, in graph g3 the engine output (average) (Pe) is relatively low, and in graph g4 the motor output (average) (Pm) is relatively high, and in graph g2 the charge state (SOC) is trending downwards.

[0035] At time t=t1, in graph g1, the hybrid vehicle 1 has reached a predetermined distance L1 from its destination 2. At this time, in graph g2, the charge state (SOC) is below the threshold P1. Therefore, in order to raise the charge state (SOC) to P1, the control device 3 starts charging control by setting the engine output (average) (Pe) to a relatively high state in graph g3 and the motor output (average) (Pm) to a relatively low state in graph g4. With the start of charging control, the charge state (SOC) in graph g2 changes from a decreasing trend to an increasing trend.

[0036] At time t=t2, in graph g1, the hybrid vehicle 1 is even closer to destination 2, and at this time, in graph g2, the charge state (SOC) exceeds the threshold P1. Therefore, the control device 3 continues driving by maintaining the SOC, setting the engine output (average) (Pe) to an intermediate state in graph g3 and the motor output (average) (Pm) to an intermediate state in graph g4, so that the charge state (SOC) remains above P1 until the hybrid vehicle 1 arrives at destination 2. As a result, the charge state (SOC) in graph g2 remains almost constant.

[0037] Then, at t=t3, hybrid vehicle 1 arrives at destination 2, and at this time the charge state (SOC) maintains a value above the threshold P1.

[0038] As described above, when the hybrid vehicle 1 arrives at destination 2, where long-term parking is expected, the charge state (SOC) will have exceeded the threshold P1. Therefore, there is no need to continue running the engine 7 to charge the battery 4 after arriving at destination 2.

[0039] (modified version) In the above embodiment, the case where the destination set in the navigation device 10 is expected to involve long-term parking was described, but destination 2 does not have to be one set in the navigation device 10. For example, locations where the vehicle has been parked for a long time may be extracted from past driving records, and these locations may be pre-set as locations where long-term parking is expected. In this case, even if destination 2 is not set in the navigation device 10, the SOC can be made to be equal to or greater than the threshold P1 before arriving at the location where long-term parking is expected.

[0040] Furthermore, users may pre-set locations where long-term parking is expected. This ensures that the charge state (SOC) is reliably above threshold P1 when arriving at a location where long-term parking is expected.

[0041] In the above embodiment, the charging of battery 4 is controlled based on the distance to a location where long-term parking is expected. However, the charging of battery 4 may be controlled based on the time required to reach destination 2 instead of distance. That is, the time required to secure the necessary charge may be calculated, and charging control may be started based on the time required to reach destination 2.

[0042] As described above, when the hybrid vehicle 1 approaches the destination 2 at a distance of L1, the charge state (SOC) is checked, and if the charge state (SOC) falls below the threshold P1, the engine output and motor output are controlled to exceed the threshold P1. Therefore, when the hybrid vehicle 1 arrives at the destination 2, the charge state (SOC) is above the threshold P1. Consequently, upon arrival at the destination 2, sufficient charge state (SOC) is secured to heat the catalyst 72 with the heating device 5 after prolonged parking, eliminating the need to continue engine operation to charge the battery 4 after arriving at the destination 2. Furthermore, if prolonged parking is not expected, there is no need to charge the battery 4 beyond what is necessary for driving, thus improving fuel efficiency and preventing battery 4 degradation. [Industrial applicability]

[0043] It can be suitably applied as a control device 3 for the battery 4 of a hybrid vehicle 1. [Explanation of Symbols]

[0044] 1. Hybrid vehicle 2 destination 3. Control device 4 Batteries 5 Heating device 6. Position Sensor 7 Engine 8 Generators 9 Motors 10 Navigation System S GPS satellite

Claims

1. The engine and Battery and A generator for charging the aforementioned battery, A catalyst for purifying the exhaust gas of the aforementioned engine, A heating device that heats the catalyst using the power of the battery, A processor that controls the drive of the generator, It has, The aforementioned processor, The generator is controlled to ensure that the battery charge level exceeds a predetermined threshold by the time the vehicle arrives at a destination where parking is expected to take place for a predetermined time or longer. The threshold is the amount of charge that can supply the power necessary to heat the catalyst, which has cooled due to parking for a predetermined time or longer, using the heating device. Hybrid vehicle.

2. The processor obtains the charge level of the battery when the distance to the destination falls below a predetermined distance. The drive of the generator is controlled based on the amount of charge acquired. The hybrid vehicle according to claim 1.

3. The processor acquires the battery charge level when the time required to reach the destination falls below a predetermined time. The drive of the generator is controlled based on the amount of charge acquired. The hybrid vehicle according to claim 1.

4. The processor obtains the battery charge level when the hybrid vehicle enters a charging area set around the destination. The drive of the generator is controlled based on the amount of charge acquired. The hybrid vehicle according to claim 1.

5. The generator is driven by the engine, The processor controls the engine's operation and controls the generator. The hybrid vehicle according to claim 1.

6. The generator is a drive motor powered by the battery, The aforementioned generator generates electricity using regenerative energy during deceleration. The hybrid vehicle according to claim 1.

7. Equipped with a navigation system, The processor uses the destination set in the navigation device as the destination. The hybrid vehicle according to claim 1.

8. It further includes a memory device that stores driving records including parking locations and parking time at those locations. The processor selects a parking location from among the parking locations stored in the storage device whose parking time is equal to or greater than the predetermined time as the destination. The hybrid vehicle according to claim 1.

9. The aforementioned destination can be set by the user. The hybrid vehicle according to claim 1.

10. The processor sets the threshold based on the ambient temperature. The hybrid vehicle according to claim 1.

Images