Catalyst temperature control device and catalyst temperature control method

Abstract

To shorten a time for raising a temperature of a catalyst when motor driving is switched to engine driving.SOLUTION: A catalyst temperature control device 60 includes: a catalyst 41 provided in an exhaust passage 13 in which exhaust gas of an engine 10 flows; a heater 42 provided upstream of the catalyst 41 in the exhaust passage 13; a bypass passage 43 connected to each of a first connection part upstream of the heater 42 in the exhaust passage 13 and a second connection part downstream of the catalyst 41 in the exhaust passage 13; a pump 44 provided in the bypass passage 43 and sending out gas from the second connection part toward the first connection part; and a control section 623 that controls the pump 44 so that the gas heated by the heater 42 while the engine 10 is stopped recirculates in the heater 42, the catalyst 41 and the bypass passage 43.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a catalyst temperature control device and a catalyst temperature control method. [Background technology]

[0002] The hybrid vehicle of Patent Document 1 heats the catalyst before switching from motor drive to engine drive, thereby reducing the emission of toxic substances caused by the catalyst temperature not reaching the activation temperature immediately after switching to engine drive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-130368 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the hybrid vehicle of Patent Document 1, if the catalyst temperature before switching to engine drive is low, it takes a long time to heat the catalyst to its activation temperature, which delays the timing of switching from motor drive to engine drive. Therefore, there is a demand to shorten the time it takes to heat the catalyst to its activation temperature when switching from motor drive to engine drive.

[0005] The present invention has been made in consideration of these points, and has an object to shorten the time it takes for the catalyst to heat up when switching from motor drive to engine drive. [Means for solving the problem]

[0006] A catalyst temperature control device according to a first aspect of the present invention includes a catalyst provided in an exhaust flow path downstream of an engine, a heater provided in the exhaust flow path upstream of the catalyst, a bypass flow path connected to a first connection portion upstream of the heater in the exhaust flow path and a second connection portion downstream of the catalyst in the exhaust flow path, a pump provided in the bypass flow path for sending gas from the second connection portion to the first connection portion, and a control portion for controlling the pump so that gas heated by the heater flows back through the heater, the catalyst, and the bypass flow path while the engine is stopped.

[0007] The control unit may control the heater and the pump such that gas flowing through the heater, the catalyst, and the bypass passage is returned in response to receiving a start instruction to start the engine.

[0008] The exhaust gas supply system may further include a first switching valve provided upstream of the heater for directing gas from the bypass flow path to the exhaust flow path, and a second switching valve provided downstream of the catalyst for directing gas from the exhaust flow path to the bypass flow path, and the control unit may control the second switching valve to direct gas from the exhaust flow path to the bypass flow path, and control the first switching valve to direct gas from the bypass flow path to the exhaust flow path, thereby returning the gas flowing through the heater, the catalyst, and the bypass flow path.

[0009] The first switching valve may be a three-way valve provided at the first connection portion, and the second switching valve may be a three-way valve provided at the second connection portion.

[0010] When a temperature of the gas in the exhaust flow path when a start instruction to start the engine is received is less than a first threshold value, the control unit may control the second switching valve to direct the gas from the exhaust flow path to the bypass flow path, and may control the first switching valve to direct the gas from the bypass flow path to the exhaust flow path.

[0011] The engine may further include a first motor for driving a vehicle equipped with the engine, and the control unit may cause the first motor to drive the vehicle from when operation of the pump begins to when operation of the pump ends.

[0012] The control unit may start the engine after a temperature of gas in the exhaust passage reaches or exceeds the first threshold value.

[0013] The engine may further include a second motor for rotating the engine, and the control unit may inject fuel from an injector into the engine by driving the second motor for a predetermined time after the temperature of gas in the exhaust passage reaches or exceeds the first threshold value.

[0014] The control unit may continue to operate the heater while stopping operation of the pump when a temperature of gas in the exhaust passage after the engine is started is less than a second threshold value.

[0015] The vehicle may further include an estimation unit that estimates a driving force source of the vehicle at a predetermined time after a current time based on a battery charge rate and a type of road on which the vehicle is traveling, and when the estimation unit estimates that the driving force sources at the current time do not include the engine and that the driving force sources at a predetermined time after the current time will include the engine, the control unit may control the heater and the pump so that gas flowing through the heater, the catalyst, and the bypass flow path is returned.

[0016] The system may further include a request unit that determines a start time from the time an instruction to start the engine is received to the time the engine starts based on the volume from the first connection to the second connection in the exhaust flow path, the volume of the bypass flow path, the volume of the catalyst, and the amount of heat generated by the heater, and outputs the start time in association with the start instruction.

[0017] A catalyst temperature control method according to a second aspect of the present invention includes a heating step of heating gas with a heater provided upstream of the catalyst in an exhaust flow path downstream of the engine while the engine is stopped, and a control step of controlling a pump provided in the bypass flow path for sending gas from the second connection portion to the first connection portion so that the heated gas circulates through a bypass flow path connected respectively to a first connection portion upstream of the heater in the exhaust flow path and a second connection portion of the catalyst in the exhaust flow path, the heater, and the catalyst. Effect of the Invention

[0018] According to the present invention, it is possible to shorten the time required for the catalyst to heat up when switching from motor drive to engine drive. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a diagram for explaining an overview of a vehicle S according to the present embodiment. [Diagram 2] FIG. 2 is a diagram showing the configuration of a catalyst temperature control device 60. [Diagram 3] 4 is a diagram showing an example of a processing sequence in a catalyst temperature control device 60. FIG. [Figure 4] FIG. 11 is a diagram showing the configuration of a catalyst temperature control device 60 according to a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] <Overview of Vehicle S> FIG. 1 is a diagram for explaining an overview of a vehicle S according to this embodiment. The vehicle S shown in FIG. 1 includes an engine 10, a plurality of injectors 11 (11a, 11b, 11c, 11d), an intake passage 12, an exhaust passage 13, a supercharger 14, a crankshaft 20, a first motor 21, a second motor 22, a clutch 23, a gear group 24, an inverter 30, a battery 31, a purification device 40, a catalyst 41, a heater 42, a bypass passage 43, a pump 44, a first switching valve 45, a second switching valve 46, a temperature sensor 47, a drive control device 50, a receiving device 51, and a catalyst temperature control device 60. The vehicle S has a function of raising the temperature of the catalyst 41 to an activation temperature by heating the heater 42 when the engine 10 starts. The activation temperature is the lowest temperature of the catalyst 41 when the purification rate of the catalyst 41 is 100%.

[0021] The engine 10 is an internal combustion engine that burns and expands a mixture of fuel and intake air to generate power. The multiple injectors 11 are components for injecting fuel in a fuel tank (not shown) into a combustion chamber in the engine 10. The intake passage 12 is a passage through which air (intake air) supplied to the engine 10 flows. The exhaust passage 13 is a passage provided downstream of the engine 10 through which the exhaust gas from the engine 10 flows. The supercharger 14 is, for example, a turbocharger, and uses the exhaust gas flow to increase the density of the intake air. The supercharger 14 has a turbine T provided in the exhaust passage 13 and a compressor C provided in the intake passage 12. The turbine T rotates by receiving the exhaust gas flowing through the exhaust passage 13. The compressor C is connected to the turbine T via a connecting shaft, and compresses the intake air by rotating together with the turbine T.

[0022] The crankshaft 20 is a shaft for converting the reciprocating motion of a piston (not shown) in the engine 10 into rotational motion. The first motor 21 is a power source that acquires electricity output from a battery 31 via an inverter 30 and generates power for driving drive wheels W of the vehicle S equipped with the engine 10. The second motor 22 is a power source that acquires electricity output from the battery 31 via the inverter 30 and generates power for rotating the engine 10. The first motor 21 and the second motor 22 generate regenerative power when the vehicle S decelerates using a brake (not shown), and supply the power to the battery 31 via the inverter 30.

[0023] The clutch 23 is a clutch that connects the first motor 21 and the second motor 22. The gear group 24 is composed of a plurality of gears having a plurality of concave and convex shapes on their outer circumferences, and includes a ring gear attached to the crankshaft 20. The other gears included in the gear group 24, which are different from the ring gear, rotate as their concave and convex shapes on their outer circumferences mesh with the concave and convex shapes of the ring gear, and transmit the rotational kinetic energy generated by the crankshaft 20 to the drive wheels W.

[0024] The inverter 30 converts the DC current output by the battery 31 into AC current and outputs it to the first motor 21, the second motor 22, the heater 42, and the pump 44. The battery 31 is a rechargeable storage battery, and supplies electricity to the first motor 21, the second motor 22, the heater 42, the pump 44, and electrical equipment (not shown) provided in the vehicle S. The battery 31 is also charged with electricity generated by a FC (Fuel Cell) stack (not shown) and regenerative power generated by the first motor 21 and the second motor 22.

[0025] The purification device 40 is a device for purifying the exhaust gas of the engine 10, and contains a catalyst 41. The catalyst 41 is, for example, a three-way catalyst provided in the exhaust passage 13, and purifies the hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) contained in the exhaust gas of the engine 10. Specifically, the catalyst 41 oxidizes the hydrocarbons to water and carbon dioxide, oxidizes the carbon monoxide to carbon dioxide, and reduces the nitrogen oxides to nitrogen. The heater 42 is a device provided upstream of the catalyst 41 in the exhaust passage 13, and heats the exhaust gas with electricity supplied from the battery 31 via the inverter 30. The heater 42 heats the exhaust gas flowing into the catalyst 41 by exchanging heat with the exhaust gas flowing through the exhaust passage 13.

[0026] The bypass path 43 is a passage through which the exhaust gas of the engine 10 flows, branching off from a first connection point (hereinafter referred to as a "branching point") provided on the upstream side of the heater 42 in the exhaust path 13 and merging into a second connection point (hereinafter referred to as a "junction point") provided on the downstream side of the catalyst 41 in the exhaust path 13. The pump 44 is a device provided in the bypass path 43 for sending gas (e.g., exhaust gas) from the junction point (second connection point) of the exhaust path 13 and the bypass path 43 to the junction point (first connection point) of the exhaust path 13 and the bypass path 43.

[0027] The first switching valve 45 is provided upstream of the heater 42 and is a switching valve for directing exhaust gas from the bypass path 43 to the exhaust path 13, and is, for example, a three-way valve provided at the branching point of the exhaust path 13 and the bypass path 43. The second switching valve 46 is provided downstream of the catalyst 41 and is a switching valve for directing exhaust gas from the exhaust path 13 to the bypass path 43, and is, for example, a three-way valve provided at the junction of the exhaust path 13 and the bypass path 43. The temperature sensor 47 is a sensor for detecting the temperature of the exhaust gas flowing into the catalyst 41.

[0028] The drive control device 50 is a device for outputting instruction information for starting or stopping the engine 10 and the second motor 22 to the catalyst temperature control device 60. For example, when the vehicle S is run in hybrid mode, the drive control device 50 outputs instruction information including a start instruction for starting the engine 10 and the second motor 22 to the catalyst temperature control device 60. For example, when the vehicle S is run in EV (Electric Vehicle) mode, the drive control device 50 outputs instruction information including a stop instruction for stopping the engine 10 and a start instruction for starting the second motor 22 to the catalyst temperature control device 60.

[0029] The receiving device 51 is a device for receiving radio waves from an external positioning system such as a Global Navigation Satellite System (GNSS). The receiving device 51 outputs the latitude and longitude calculated based on the information included in the received radio waves to the catalyst temperature control device 60 as position information of the vehicle S. In other words, the receiving device 51 functions as a position identifying device that identifies the position of the vehicle S.

[0030] The catalyst temperature control device 60 is a housing including electronic components or a printed circuit board on which electronic components are mounted. When the catalyst temperature control device 60 receives instruction information (hereinafter, sometimes referred to as a "start instruction") indicating a request to start the engine 10 from the drive control device 50, the catalyst temperature control device 60 executes a process of starting the engine 10 after heating the heater 42 to raise the temperature of the catalyst 41 to the activation temperature. By starting the engine 10 after raising the temperature of the catalyst 41 to the activation temperature in this way, the catalyst temperature control device 60 can purify toxic substances contained in the exhaust even immediately after the engine 10 is started. However, since the time from when the start instruction for the engine 10 is received until the engine 10 starts includes the time to raise the temperature of the catalyst 41 to the activation temperature, the timing of starting the engine 10 may be delayed depending on the catalyst 41 at the time when the start instruction is received.

[0031] Therefore, the catalyst temperature control device 60 controls the second switching valve 46 to direct the exhaust gas from the downstream of the catalyst 41 in the exhaust passage 13 to the bypass passage 43, controls the first switching valve 45 to direct the exhaust gas from the bypass passage 43 to the upstream of the heater 42 in the exhaust passage 13, and then operates the pump 44 and the heater 42. In this case, the exhaust gas that has passed through the catalyst 41 flows through the bypass passage 43 and passes through the heater 42, so that the temperature of the exhaust gas is further increased. Then, the high-temperature exhaust gas passes through the catalyst 41, so that the temperature of the catalyst 41 is likely to be further increased. By repeating the above-mentioned flow of the exhaust gas, the time required to raise the temperature of the catalyst 41 to the activation temperature can be shortened, so that the delay in the timing of starting the engine 10 can be suppressed. The configuration and operation of the catalyst temperature control device 60 will now be described in detail.

[0032] <Configuration of catalyst temperature control device 60> 2 is a diagram showing a configuration of the catalyst temperature control device 60. The catalyst temperature control device 60 has a storage unit 61 and a processor 62. The processor 62 has a reception unit 621, an acquisition unit 622, and a control unit 623.

[0033] The storage unit 61 has a storage medium such as a read only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), or a solid state drive (SSD). The storage unit 61 stores a program executed by the processor 62. The storage unit 61 stores various information for raising the temperature of the catalyst 41 to an activation temperature before starting the engine 10.

[0034] The processor 62 is, for example, a CPU (Central Processing Unit) or an ECU (Electronic Control Unit). The processor 62 executes a program stored in the storage unit 61 to function as a reception unit 621, an acquisition unit 622, and a control unit 623. The processor 62 may be configured as one processor, or may be configured as a combination of multiple processors or one or more processors and an electronic circuit. The configuration of each unit realized by the processor 62 will be described below.

[0035] The reception unit 621 receives instruction information from the drive control device 50. The instruction information includes at least any one of an engine start instruction for starting the engine 10, an engine stop instruction for stopping the engine 10, a motor start instruction for starting the second motor 22, and a motor stop instruction for stopping the second motor 22. For example, when switching the vehicle S from the EV mode to the hybrid mode, the reception unit 621 receives an engine start instruction for starting the engine 10.

[0036] The acquisition unit 622 acquires the exhaust temperature detected by the temperature sensor 47. The acquisition unit 622 acquires the exhaust temperature detected by the temperature sensor 47 every time a certain period of time has elapsed. By acquiring the exhaust temperature, the acquisition unit 622 can specify the exhaust temperature of the exhaust gas that exchanges heat with the catalyst 41, and therefore the control unit 623 can determine whether the temperature of the catalyst 41 has reached the activation temperature.

[0037] The control unit 623 controls the first switching valve 45, the second switching valve 46, the heater 42, and the pump 44 based on at least one of an engine start instruction, an engine stop instruction, a motor start instruction, and a motor stop instruction included in the instruction information received by the receiving unit 621.

[0038] When the reception unit 621 receives an engine start instruction, the control unit 623 controls the second switching valve 46 to direct the exhaust gas from the exhaust passage 13 to the bypass passage 43, and controls the first switching valve 45 to direct the exhaust gas from the bypass passage 43 to the exhaust passage 13. When the reception unit 621 receives an engine start instruction, for example, the control unit 623 controls the pump 44 so that the gas (e.g., exhaust gas) heated by the heater 42 circulates through the heater 42, the catalyst 41, and the bypass passage 43 while the engine 10 is stopped. That is, the control unit 623 configures a closed loop in which the catalyst 41, the heater 42, and the pump 44 are provided. Next, the control unit 623 operates the heater 42 and the pump 44 to circulate the exhaust gas in the configured closed loop and to exchange heat between the heated heater 42 and the exhaust gas. As a result of the control unit 623 operating as described above, the exhaust gas that has passed through the catalyst 41 flows through the bypass path 43 and passes through the heater 42, thereby further increasing the temperature of the exhaust gas. Thereafter, as the high-temperature exhaust gas passes through the catalyst 41, the temperature of the catalyst 41 is likely to become even higher. Then, by repeating the above-described flow, the time required to raise the temperature of the catalyst 41 to its activation temperature can be shortened.

[0039] For example, when the temperature of the exhaust gas when the reception unit 621 receives the engine start instruction is less than a first threshold value, the control unit 623 controls the second switching valve 46 to direct the exhaust gas from the exhaust passage 13 to the bypass passage 43, and controls the first switching valve 45 to direct the exhaust gas from the bypass passage 43 to the exhaust passage 13. The first threshold value is the exhaust gas temperature when the temperature of the catalyst 41 reaches the activation temperature, and is, for example, 250°C. By operating the control unit 623 in this manner, the catalyst 41 can be heated if the purification rate of the catalyst 41 is less than 100% when the engine start instruction is received, so that the engine 10 can be started in a state in which the catalyst 41 is activated. Furthermore, when the purification rate of the catalyst 41 is 100% when the engine start instruction is received, the engine 10 can be started without raising the temperature of the catalyst 41, so that a delay in the timing of starting the engine 10 can be suppressed.

[0040] For example, the control unit 623 controls the second switching valve 46 and the first switching valve 45 to configure a closed loop, and then causes the first motor 21 to drive the vehicle S from when the operation of the pump 44 starts to when the operation of the pump 44 ends. By the control unit 623 operating in this manner, the vehicle S can be driven even when the engine 10 is stopped during the period from when the reception unit 621 receives the engine start instruction to when the engine 10 starts.

[0041] The control unit 623 starts the engine 10 after the temperature of the exhaust gas circulating in the closed loop formed by controlling the second switching valve 46 and the first switching valve 45 reaches a first threshold value or more. For example, when the exhaust gas temperature acquired by the acquisition unit 622 is equal to or higher than the first threshold value, the control unit 623 stops the operation of the heater 42 and the pump 44. Then, the control unit 623 controls the second switching valve 46 so that the exhaust gas flows from the downstream of the catalyst 41 to the outside of the vehicle S, and controls the first switching valve 45 so that the exhaust gas flows from the engine 10 to the heater 42, and then starts the engine 10. By the control unit 623 operating in this manner, the engine 10 can be started with the catalyst 41 activated, so that the exhaust gas purified by the catalyst 41 can be discharged even immediately after the engine 10 is started.

[0042] Furthermore, the control unit 623 may cause the second motor 22, which has less vibration and noise and greater output than a starter motor (not shown), to start the engine 10. For example, after the exhaust temperature reaches a first threshold value or higher, the control unit 623 drives the second motor 22 for a predetermined time, thereby causing the injector 11 to inject fuel into the engine 10. The predetermined time is, for example, a time shorter than the time required to start the engine 10 using a starter motor, and is determined by experiment or simulation.

[0043] By operating the control unit 623 as described above, the engine can be started using the second motor 22, which has less vibration and noise than a starter motor, and therefore NV (Noise Vibration) performance can be improved. Furthermore, by using the second motor 22, which has a greater output than a starter motor, the engine 10 can be started in a shorter time and with a higher probability than with a starter motor. As a result, the engine 10 can be started without performing an operation such as injecting more fuel than when driving, with the aim of starting the engine 10 with a higher probability, and therefore an increase in exhaust emissions when starting the engine 10 can be suppressed.

[0044] <Processing sequence in catalyst temperature control device 60> Fig. 3 is a diagram showing an example of a processing sequence in the catalyst temperature control device 60. The processing sequence shown in Fig. 3 is a sequence showing the operation from when an engine start command is received from the drive control device 50 to when the engine 10 is started.

[0045] The reception unit 621 receives an engine start instruction from the engine control device 50 (S10). The acquisition unit 622 acquires the exhaust temperature T1 detected by the temperature sensor 47 (S11). If the exhaust temperature T1 is equal to or higher than the first threshold value (NO in S12), the control unit 623 drives the second motor 22 for a predetermined time (S20) and causes the injector 11 to inject fuel (S21), thereby starting the engine 10.

[0046] If the exhaust temperature T1 is less than the first threshold value (YES in S12), the control unit 623 controls the second switching valve 46 to direct the exhaust from the exhaust path 13 to the bypass path 43, and controls the first switching valve 45 to direct the exhaust from the bypass path 43 to the exhaust path 13 (S13). That is, the control unit 623 configures a closed loop in which the catalyst 41, the heater 42, and the pump 44 are provided. Next, the control unit 623 operates the pump 44 and the heater 42 (S14), thereby circulating the exhaust within the closed loop and exchanging heat between the heated heater 42 and the exhaust.

[0047] The acquiring unit 622 further acquires the exhaust temperature T2 (S15). If the exhaust temperature T2 is less than the first threshold (NO in S16), the catalyst temperature control device 60 repeats the operation of the control unit 623 driving the first motor 21 to drive the vehicle S (S17) and the operation of the acquiring unit 622 further acquiring the exhaust temperature T2 (S15). If the exhaust temperature T2 is equal to or greater than the first threshold (YES in S16), the control unit 623 stops the heater 42 and the pump 44 (S18), controls the second switching valve 46 so that the exhaust flows from downstream of the catalyst 41 to the outside of the vehicle S, and controls the first switching valve 45 so that the exhaust flows from the engine 10 to the heater 42 (S19). Then, the control unit 623 drives the second motor 22 for a predetermined time (S20) and starts the engine 10 by injecting fuel from the injector 11 (S21).

[0048] <First Modification> In the above description, the control unit 623 has exemplified an operation in which the engine 10 is started with the heater 42 and the pump 44 stopped, but this is not limiting. The control unit 623 may continue the operation of the heater 42 after starting the engine 10. If the temperature of the exhaust gas after the engine 10 is started is less than the second threshold, the control unit 623 may continue the operation of the heater 42 with the operation of the pump 44 stopped. The second threshold indicates a temperature higher than the temperature indicated by the first threshold, and is determined by experiment or simulation.

[0049] For example, when the exhaust temperature acquired by the acquisition unit 622 is equal to or higher than the first threshold, the control unit 623 stops the pump 44 while continuing the operation of the heater 42. Then, the control unit 623 controls the second changeover valve 46 so that the exhaust flows from downstream of the catalyst 41 to the outside of the vehicle S, controls the first changeover valve 45 so that the exhaust flows from the engine 10 to the heater 42, and then starts the engine 10. Next, when the exhaust temperature acquired by the acquisition unit 622 after starting the engine 10 is less than the second threshold, the control unit 623 further continues the operation of the heater 42. By operating in this manner, the control unit 623 can prevent the temperature of the catalyst 41, which has exchanged heat with low-temperature exhaust gas, from becoming lower than the activation temperature after the engine 10 is started.

[0050] <Second Modification> In the above description, the catalyst temperature control device 60 starts the engine 10 and the second motor 22 by receiving command information from the drive control device 50, but the present invention is not limited to this. The catalyst temperature control device 60 may estimate a drive mode (e.g., hybrid mode, EV mode) suitable for the running of the vehicle S based on the running state of the vehicle S, and generate command information based on the drive mode. FIG. 4 is a diagram showing a configuration of the catalyst temperature control device 60 according to a second modified example. The catalyst temperature control device 60 shown in FIG. 4 differs from the catalyst temperature control device 60 shown in FIG. 2 in that it has an estimation unit 624 and a request unit 625, but is the same in other respects.

[0051] The estimation unit 624 estimates the driving force source of the vehicle S at a time when a predetermined time has elapsed from the current time based on the charging rate of the battery 31 and the type of road on which the vehicle S travels. The predetermined time is the time until the temperature of the catalyst 41 reaches the activation temperature, which is determined by an experiment or a simulation, and is, for example, 20 seconds. By determining the predetermined time in this manner, it is possible to match the estimated time when the driving force source of the vehicle S may be switched with the time when the temperature of the catalyst 41 reaches the activation temperature if an engine start instruction is output to the reception unit 621 at the current time (i.e., the time when the engine 10 starts). The estimation unit 624 repeats the above operation, for example, every time a certain time (for example, 0.1 seconds) has elapsed.

[0052] The estimation unit 624 acquires, for example, the charging rate from the battery 31. For example, when the acquired charging rate is less than a predetermined charging rate, the estimation unit 624 estimates that the driving force source of the vehicle S at a time when a predetermined time has elapsed from the current time is the engine 10 and the first motor 21. The predetermined charging rate is a charging rate corresponding to the charge amount for operating the first motor 21, the second motor 22, the heater 42, the pump 44, and the electrical equipment equipped in the vehicle S at the predetermined time. On the other hand, when the acquired charging rate is equal to or higher than the predetermined charging rate, the estimation unit 624 estimates that the driving force source of the vehicle S at a time when a predetermined time has elapsed from the current time is the first motor 21.

[0053] The estimation unit 624 also acquires position information indicating the latitude and longitude of the vehicle S from the receiving device 51. The estimation unit 624 refers to the position and road type included in the map information stored in the storage unit 61, thereby identifying the position and type of the road (i.e., the position and type of the road on which the vehicle S is traveling at the current time) corresponding to the latitude and longitude indicated in the position information acquired from the receiving device 51. Then, based on the identified road position, the traveling direction of the vehicle S, and the vehicle speed of the vehicle S, the estimation unit 624 identifies the position and type of the road on which the vehicle S is traveling at a time a predetermined time has elapsed from the current time.

[0054] Then, as an example, when the type of the identified road is an expressway, the estimation unit 624 estimates that the driving force source of the vehicle S at a time when a predetermined time has elapsed from the current time is the first motor 21. On the other hand, when the type of the identified road is an ordinary road, the estimation unit 624 estimates that the driving force source of the vehicle S at a time when a predetermined time has elapsed from the current time is the engine 10 and the first motor 21.

[0055] If the engine 10 is not included in the driving power sources at the current time and the engine 10 is included in the driving power sources at a time a predetermined time has elapsed from the current time as estimated by the estimation unit 624, the request unit 625 outputs an engine start instruction to the reception unit 621. Furthermore, if the engine 10 is included in the driving power sources at the current time and the engine 10 is not included in the driving power sources at a time a predetermined time has elapsed from the current time as estimated by the estimation unit 624, the request unit 625 outputs an engine stop instruction to the reception unit 621. The request unit 625 repeats the above operation, for example, every time a certain time (for example, 0.1 seconds) has elapsed.

[0056] By operating the request unit 625 as described above, the time when the temperature of the catalyst 41 reaches the activation temperature can be made to coincide with the desired time to start the engine 10. As a result, the request unit 625 can suppress a delay in the timing of switching from driving the first motor 21 to driving the engine 10 due to the temperature of the catalyst 41 not reaching the activation temperature.

[0057] Furthermore, the request unit 625 may output a start time at which the engine 10 starts to the reception unit 621 in association with the engine start instruction. The start time is the time from the time the reception unit 621 receives the engine start instruction to the time at which the engine 10 starts. The request unit 625 determines the start time based on, for example, the volume of the exhaust path 13 from the branch point to the junction point with the bypass path 43, the volume of the bypass path 43, the volume of the catalyst 41, and the amount of heat generated by the heater 42. The volume from the branch point to the junction point, the volume of the bypass path 43, the volume of the catalyst 41, and the amount of heat generated by the heater 42 are stored in the storage unit 61.

[0058] For example, the request unit 625 lengthens the start time as the volume from the branch point to the junction point, the volume of the bypass passage 43, and the volume of the catalyst are larger. For example, the request unit 625 shortens the start time as the amount of heat generated by the heater 42 is larger. Then, the request unit 625 outputs the determined start time to the reception unit 621 in association with the engine start instruction. By operating the request unit 625 in this manner, even if the time until the temperature of the catalyst 41 reaches the activation temperature differs depending on the type of vehicle, the time can be made to match the time until the time at which the engine 10 is desired to be started. In other words, the time at which the temperature of the catalyst 41 reaches the activation temperature can be made to match the time at which the engine 10 is desired to be started.

[0059] <Third Modification> In the above description, the operation of the first switching valve 45 and the second switching valve 46 is exemplified as a three-way valve, but is not limited thereto. At least one of the first switching valve 45 and the second switching valve 46 may be configured as two two-way valves or flap valves. For example, the first switching valve 45 may be configured as a two-way valve or a flap valve provided in the exhaust passage 13 upstream of a junction of the exhaust passage 13 and the bypass passage 43 and upstream of the junction of the bypass passage 43. The second switching valve 46 may be configured as a two-way valve or a flap valve provided in the exhaust passage 13 downstream of a junction of the exhaust passage 13 and the bypass passage 43 and downstream of the junction of the bypass passage 43.

[0060] <Effects of the catalyst temperature control device 60> As described above, when the catalyst temperature control device 60 receives an engine start instruction, it has a control unit 623 that controls the second switching valve 46 to direct exhaust from downstream of the catalyst 41 in the exhaust path 13 to the bypass path 43, controls the first switching valve 45 to direct exhaust from the bypass path 43 to upstream of the heater 42 in the exhaust path 13, and operates the heater 42 and the pump 44.

[0061] With the catalyst temperature control device 60 configured in this manner, the exhaust gas that has passed through the catalyst 41 flows through the bypass passage 43 and passes through the heater 42, thereby further increasing the temperature of the exhaust gas. Thereafter, the high-temperature exhaust gas passes through the catalyst 41, which tends to further increase the temperature of the catalyst 41. Then, by repeating the above-described flow, the time required to raise the temperature of the catalyst 41 to its activation temperature can be shortened, thereby suppressing a delay in the timing of starting the engine 10.

[0062] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by distributing or integrating functionally or physically in any unit. In addition, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effect of the new embodiment resulting from the combination combines the effect of the original embodiment. [Explanation of symbols]

[0063] 10 Engine 11a Injector 11b Injector 11c injector 11d Injector 12 Intake passage 13 Exhaust duct 14 Turbocharger 20 Crankshaft 21 First motor 22 Second motor 23 Clutch 24 Gears 30 Inverter 31 Battery 40 Purification Equipment 41 Catalyst 42 Heater 43 Bypass Road 44 Pump 45 First switching valve 46 Second switching valve 47 Temperature Sensor 50 Drive control device 51 Receiving device 60 Catalyst temperature control device 61 Storage section 62 processors 621 Reception Department 622 Acquisition Department 623 Control Unit 624 Estimation Department 625 Request part

Claims

1. a catalyst disposed in an exhaust flow path downstream of the engine; a heater provided upstream of the catalyst in the exhaust flow path; a bypass flow path connected to a first connection portion on the upstream side of the heater in the exhaust flow path and a second connection portion on the downstream side of the catalyst in the exhaust flow path; a pump provided in the bypass flow path and configured to deliver gas from the second connection portion toward the first connection portion; a control unit that controls the pump so that gas heated by the heater circulates through the heater, the catalyst, and the bypass flow path while the engine is stopped; A catalyst temperature control device having a

2. the control unit controls the heater and the pump in response to receiving a start instruction for starting the engine so that the gas flowing through the heater, the catalyst, and the bypass flow path is returned. The catalyst temperature control device according to claim 1 .

3. a first switching valve provided upstream of the heater and configured to direct gas from the bypass passage to the exhaust passage; a second switching valve provided downstream of the catalyst and configured to direct gas from the exhaust passage to the bypass passage; and The control unit controls the second switching valve to direct the gas from the exhaust flow path to the bypass flow path, and controls the first switching valve to direct the gas from the bypass flow path to the exhaust flow path, thereby returning the gas flowing through the heater, the catalyst, and the bypass flow path. The catalyst temperature control device according to claim 1 .

4. the first switching valve is a three-way valve provided at the first connection portion, The second switching valve is a three-way valve provided at the second connection portion. The catalyst temperature control device according to claim 3 .

5. When a temperature of the gas in the exhaust flow path at the time of receiving a start instruction for starting the engine is less than a first threshold value, the control unit controls the second switching valve to direct the gas from the exhaust flow path to the bypass flow path, and controls the first switching valve to direct the gas from the bypass flow path to the exhaust flow path. The catalyst temperature control device according to claim 4.

6. a first motor for driving a vehicle having the engine; The control unit causes the first motor to drive the vehicle from when the operation of the pump starts to when the operation of the pump ends. The catalyst temperature control device according to claim 1 .

7. The control unit starts the engine after the temperature of the gas in the exhaust flow path reaches or exceeds the first threshold value. The catalyst temperature control device according to claim 5 .

8. a second motor for rotating the engine; the control unit drives the second motor for a predetermined time after a temperature of the gas in the exhaust passage reaches or exceeds the first threshold, thereby causing the injector to inject fuel into the engine. The catalyst temperature control device according to claim 7.

9. When a temperature of the gas in the exhaust passage after the engine is started is less than a second threshold value, the control unit continues operation of the heater while stopping operation of the pump. The catalyst temperature control device according to claim 8.

10. an estimation unit that estimates a driving force source of the vehicle at a time when a predetermined time has elapsed from a current time based on a charging rate of the battery and a type of road on which the vehicle is traveling; When the estimation unit estimates that the driving force sources at the current time do not include the engine and that the driving force sources at a time when a predetermined time has elapsed from the current time will include the engine, the control unit controls the heater and the pump so that the gas flowing through the heater, the catalyst, and the bypass flow path is returned. The catalyst temperature control device according to claim 1 .

11. a request unit that determines a start time from a time when a start instruction for the engine is received to a time when the engine is started based on a volume from the first connection part to the second connection part in the exhaust flow path, a volume of the bypass flow path, a volume of the catalyst, and an amount of heat generated by the heater, and outputs the start time in association with the start instruction. The catalyst temperature control device according to claim 10.

12. a heating step of heating gas with a heater provided upstream of a catalyst in an exhaust flow path downstream of the engine while the engine is stopped; a control process of controlling a pump that delivers gas from a second connection portion provided in the bypass flow path toward the first connection portion, such that the heated gas flows back through a bypass flow path that is respectively connected to a first connection portion upstream of the heater in the exhaust flow path and a second connection portion of the catalyst in the exhaust flow path, the heater, and the catalyst; A catalyst temperature control method comprising the steps of:

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