Engine system control unit

Abstract

To provide a control device of an engine system in which an excessive rise of a temperature of a catalyst is suppressed by an easy control.SOLUTION: A control device of an engine system having an engine and a catalyst for purifying the exhaust air of the engine comprises: a determination part for performing determination processing for predicting whether or not the catalyst is excessively raised in a temperature by the execution of warmup processing for raising the temperature of the catalyst up to a warmup temperature on the basis of a temperature of the engine and the temperature of the catalyst; and a stop part for stopping the control device on the basis of a determination result. When the determination result is non-affirmative, the stop part stops the control device, when the determination result is affirmative, the determination part re-executes the determination processing, when the determination result is affirmative, and there arises an activation requirement of the engine system, the engine is started without performing the warmup processing of the catalyst, and when the determination result is non-affirmative, the control device is stopped.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a control device for an engine system.

Background Art

[0002] When the temperature of the catalyst at engine startup is below a predetermined value, the ECU (Electronic Control Unit) starts the engine and executes a warm-up process to raise the temperature of the catalyst to the warm-up temperature (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above technology, the temperature of the catalyst at engine startup is estimated based on the length of the engine stop period and the outside air temperature during the stop period. In this method, the estimated catalyst temperature at engine startup is a constant value under the same conditions of the length of the stop period and the outside air temperature. However, the temperature of the catalyst at engine stop varies depending on the operating state of the engine up to that point. Therefore, there is a possibility that the estimated temperature of the catalyst at engine startup may deviate significantly from the actual temperature. As a result, for example, if the estimated temperature of the catalyst is estimated to be lower than the actual temperature, there is a risk that the warm-up process will be executed at engine startup and the catalyst will overheat

[0005] <0000og>

[0006] Therefore, the present invention aims to provide an engine system control device that suppresses catalyst overheating through simple control. [Means for solving the problem]

[0007] The above objective is a control device for an engine system having an engine and a catalyst for purifying the exhaust gas of the engine, comprising: an engine control unit that starts the engine and performs a warm-up process to raise the temperature of the catalyst to the warm-up temperature when the temperature of the engine is below the cold temperature at the first start of the engine after the control device has been started, and stops the engine when there is a request to stop the engine system; a detection unit that detects the temperature of the engine when there is a request to stop; an estimation unit that estimates the temperature of the catalyst based on the operating state of the engine from when the engine is started until the request to stop is made, and a control device that, when there is a request to stop, determines the temperature of the catalyst based on the temperature of the engine and the temperature of the catalyst. This can be achieved by an engine system control device comprising: a determination unit that performs a determination process to predict whether the warm-up process will be performed and whether the catalyst will overheat when the engine is started for the first time after the next startup of the control device; and a stop unit that stops the control device based on the determination result of the determination unit, wherein if the determination result is negative, the stop unit stops the control device; if the determination result is positive, the determination unit re-executes the determination process; if the determination result is positive and there is a request to start the engine system, the engine control unit starts the engine without performing the warm-up process; and if the determination result after re-executing the determination process is negative, the stop unit stops the control device.

[0008] In the above configuration, when there is a request to stop the engine system, the control device determines, based on the engine temperature and the catalyst temperature, whether or not a warm-up process will be performed during the first engine start after the next startup, causing the catalyst to overheat. If the determination result is positive and there is a request to start the engine system, the engine is started without performing a warm-up process. This suppresses overheating of the catalyst due to the warm-up process.

[0009] Furthermore, in the above configuration, the judgment process is executed again until the judgment result is negative, at which point the control device stops. In this case, the warm-up process is executed if the engine temperature at the first start of the engine after the control device has been started is below the cold temperature. As described above, it is not necessary to estimate the catalyst temperature at the next engine start in order to determine whether or not to perform the warm-up process at the next engine start. For this reason, it is also not necessary to measure the engine stop period or to obtain the outside temperature during the engine stop period. Control is simplified in this way.

[0010] The engine system may include a motor that motorizes the engine with fuel injection stopped and the throttle valve open, and a motoring control unit that performs motoring of the engine by the motor if the determination result is positive.

[0011] The engine system includes a radiator for cooling the engine's coolant and a fan for cooling the radiator and the catalyst, and may also include a fan control unit that drives the fan if the determination result is positive.

[0012] If a stop request is made, and the engine temperature is below the cold temperature and the catalyst temperature is above a limit temperature lower than the warm-up temperature, the determination unit makes an affirmative determination. If a stop request is made, and the engine temperature is above the cold temperature or the catalyst temperature is below the limit temperature, the determination unit makes a negative determination. The limit temperature may be the temperature at which the catalyst overheats due to the warm-up process performed during the first engine start-up after the next startup of the control device.

[0013] If there is a stop request and the engine temperature is higher than the cold temperature, the determination unit predicts that the warm-up process will not be performed when the engine is first started after the control device is started and makes the denial determination. If there is a stop request and the catalyst temperature is below the limit temperature, the determination unit may predict that the catalyst will not overheat even if the warm-up process is performed when the engine is first started after the control device is started and makes the denial determination. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide an engine system control device in which excessive temperature rise of the catalyst is suppressed by simple control. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram of the engine system. [Figure 2] This is a schematic diagram of the engine configuration located in the engine compartment of the vehicle body. [Figure 3] This flowchart illustrates the over-temperature suppression control performed by the ECU. [Figure 4] This is a timing chart illustrating over-temperature suppression control. [Figure 5] This is a timing chart illustrating over-temperature suppression control. [Figure 6] This is a timing chart illustrating over-temperature suppression control. [Figure 7]This is a timing chart illustrating over-temperature rise suppression control.

Embodiments for Carrying Out the Invention

[0016] [Schematic Configuration of Hybrid Vehicle] FIG. 1 is a schematic configuration diagram of an engine system 1. In this embodiment, the engine system 1 is mounted on a hybrid vehicle. The engine system 1 includes an ECU (Electronic Control Unit) 100, an engine 10, a first motor generator (hereinafter referred to as "first MG (Motor Generator)") 14, a second motor generator (hereinafter referred to as "second MG") 15, a PCU (Power Control Unit) 17, a battery 18, a power split mechanism 50, a transmission mechanism 51, a transmission 52, a drive shaft 53, a differential 54, and drive wheels 55. The engine 10 is a gasoline engine, but is not limited thereto and may be a diesel engine. The engine 10, the first MG 14, and the second MG 15 are power sources for driving the hybrid vehicle.

[0017] Each of the first MG 14 and the second MG 15 has a function as a motor that outputs torque by power supply and a function as a generator that generates regenerative power when torque is applied. The first MG 14 and the second MG 15 are electrically connected to the battery 18 via the PCU 17. The PCU 17 supplies power from the battery 18 to the first MG 14 or the second MG 15. The PCU 17 causes the battery 18 to receive the regenerative power generated by the first MG 14 or the second MG 15.

[0018] The power split mechanism 50 mechanically connects the crankshaft of the engine 10, the rotating shaft of the first MG 14, and the output shaft of the power split mechanism 50. The output shaft of the power split mechanism 50 is connected to the transmission mechanism 51. The rotating shaft of the second MG 15 is connected to the transmission mechanism 51. The transmission mechanism 51 is connected to the transmission 52. The transmission 52 is connected to the drive shaft 53. The driving forces of the engine 10, the first MG 14, and the second MG 15 are transmitted to the drive wheels 55 via the transmission mechanism 51, the transmission 52, the drive shaft 53, and the differential 54.

[0019] The transmission 52 is a stepped automatic transmission provided between the second MG 15 and the drive shaft 53. The transmission 52 changes the gear ratio under the control of the ECU 100.

[0020] The ECU 100 is an electronic control unit including an arithmetic processing circuit that performs various arithmetic processes related to the vehicle running control, and a memory that stores control programs and data. The ECU 100 is an example of a control device for the engine system. The ECU 100 functionally realizes an engine control unit, a detection unit, an estimation unit, a determination unit, a stop unit, a motor ring control unit, and a fan control unit, which will be described later.

[0021] The power switch 71, the water temperature sensor 72, the crank angle sensor 73, and the air flow meter 74 are electrically connected to the ECU 100. By turning on and off the power switch 71, the engine system 1 can be switched between ready-on in which the engine system 1 starts and can run, and ready-off in which the engine system 1 stops and cannot run. The water temperature sensor 72 detects the temperature of the cooling water of the engine 10. The temperature of the cooling water is an example of the temperature of the engine 10. The crank angle sensor 73 detects the rotational speed of the engine 10. The air flow meter 74 detects the intake air amount of the engine 10.

[0022] If the required driving force of the engine system 1 is less than a predetermined switching value, the ECU 100 switches the driving mode of the engine system 1 to motor driving mode. Motor driving mode is a driving mode in which the engine 10 is stopped and at least one of the first MG 14 and the second MG 15 is used as the power source. In motor driving mode, the engine 10 is stopped. This improves fuel efficiency.

[0023] When the power switch 71 is switched from ready on to ready off, the ECU 100 considers this to be a request to stop the engine system 1 and stops the engine 10. Subsequently, when the power switch 71 is switched from ready off to ready on, the ECU 100 considers this to be a request to start the engine system 1 and starts up and starts the engine 10. Furthermore, as will be described in more detail later, the ECU 100 starts the engine 10 and performs a warm-up process when predetermined conditions are met.

[0024] [Engine Overview] Figure 2 is a schematic diagram of the engine 10 mounted in the engine compartment 3 of the vehicle body 2. The engine 10 includes an engine body 10a, an intake pipe 11i, and an exhaust pipe 11e. The intake pipe 11i and the exhaust pipe 11e are connected to the engine body 10a. The intake pipe 11i is equipped with a throttle valve 12v for adjusting the amount of intake air. The exhaust pipe 11e is equipped with a catalyst 12c for purifying exhaust gases. A radiator 5 and a fan 6 are located in the engine compartment 3. The radiator 5 cools the coolant by promoting heat exchange between the coolant of the engine 10 and the outside air.

[0025] A grille shutter 4 is provided at the front of the vehicle body 2. A radiator 5 is positioned opposite the grille shutter 4. A fan 6 is positioned behind the radiator 5. When the fan 6 is driven, outside air is introduced into the engine compartment 3 via the grille shutter 4. As a result, the radiator 5 is cooled. In addition, when the fan 6 is driven, outside air flows through the engine compartment 3 and cools the catalytic converter 12c. In other words, the fan 6 cools both the radiator 5 and the catalytic converter 12c.

[0026] [Warm-up process] The ECU 100 starts the engine 10 and performs a warm-up process when predetermined conditions are met. The warm-up process is a process to raise the temperature of the catalyst 12c to the warm-up temperature T3. The warm-up process is a process that controls the ignition timing of the engine 10 to a retarded position compared to the optimal ignition timing. This increases the exhaust temperature and promotes the heating of the catalyst 12c. The warm-up temperature T3 is the minimum temperature at which the exhaust purification efficiency of the catalyst 12c is maintained at a high level. The predetermined conditions mentioned above are that the coolant temperature at the first start of the engine 10 after the ECU 100 has been activated is below the cold temperature T1. The cold temperature T1 is the maximum temperature at which the temperature of the catalyst 12c can be considered to be below the warm-up temperature T3. When the coolant temperature at the first start is below the cold temperature T1, the temperature of the catalyst 12c is also considered to be sufficiently low. In this way, by performing a warm-up process along with the start of the engine 10, the temperature of the catalyst 12c is raised and exhaust emissions are reduced.

[0027] As described above, if a warm-up process is performed when starting the engine 10, the catalytic converter 12c may overheat. Therefore, the ECU 100 implements the following control to suppress the overheating of the catalytic converter 12c.

[0028] [Overheating suppression control] Figure 3 is a flowchart illustrating the over-temperature suppression control performed by the ECU 100. The ECU 100 determines whether or not it is in a ready-off state based on the power switch 71 (step S1). The ready-off state is when there is a request to stop the engine system 1, as described above. If the answer in step S1 is No, this control ends. If the answer in step S1 is Yes, that is, when the power switch 71 is operated from on to off, the engine 10 is stopped (step S2).

[0029] Next, the ECU 100 detects the coolant temperature and estimates the temperature of the catalyst 12c (step S3). The coolant temperature is detected based on the water temperature sensor 72. The catalyst temperature is estimated based on the operating state of the engine 10 from when it starts up until it reaches the ready-off state. Specifically, the catalyst temperature is estimated based on the cumulative load of the engine 10 from when it starts up until it reaches the ready-off state. The larger the cumulative value, the higher the estimated catalyst temperature. After the engine 10 stops, the catalyst temperature is estimated based on the catalyst temperature estimated by the above method and the elapsed time since the engine stopped. The longer the elapsed time since the engine stopped, the lower the estimated catalyst temperature. Note that the catalyst temperature estimation is performed while the ECU 100 is running. Step S3 is an example of the processing performed by the detection unit and the estimation unit.

[0030] Next, the ECU 100 performs a determination process (step S4). The determination process predicts whether the catalyst 12c will overheat due to warm-up treatment during the first start of the engine 10 after the next startup of the ECU 100, based on the coolant temperature and the estimated catalyst temperature. Specifically, if the coolant temperature is below the cold temperature T1 and the estimated catalyst temperature is above the limit temperature T2, which is lower than the warm-up temperature T3, the ECU 100 determines that the catalyst 12c will overheat (hereinafter referred to as a positive determination). This is because, if the coolant temperature is below the cold temperature T1, it is predicted that warm-up treatment will be performed during the first start of the engine 10 after the next startup of the ECU 100. Also, if the estimated catalyst temperature is above the limit temperature T2, it is predicted that the catalyst 12c will overheat due to the warm-up treatment performed during the first start of the engine 10 after the next startup of the ECU 100. Therefore, the limit temperature T2 is the minimum temperature at which the catalyst 12c overheats due to the warm-up process performed during the first start of the engine 10 after the next startup of the ECU 100.

[0031] If the coolant temperature is higher than the cold temperature T1, or if the estimated catalyst temperature is below the limit temperature T2, the ECU 100 determines that the catalyst 12c will not overheat (hereinafter referred to as a negative determination). This is because, if the coolant temperature is higher than the cold temperature T1, it is predicted that the warm-up process will not be performed when the engine 10 is started for the first time after the next start of the ECU 100. If the estimated catalyst temperature is below the limit temperature T2, it is predicted that the catalyst 12c will not overheat even if the warm-up process is performed when the engine 10 is started for the first time after the next start of the ECU 100. Step S5 is an example of a process performed by the determination unit.

[0032] Next, the ECU 100 determines whether the judgment result was a positive result (step S5). If the result in step S5 is No, that is, if it is determined that the catalyst 12c will not overheat, the ECU 100 stops (step S6). Step S6 is an example of the process performed by the stopping unit.

[0033] If the answer in step S5 is Yes, that is, if it is determined that the catalyst 12c is overheating, the ECU 100 motorizes the engine 10 with the first MG 14 and drives the fan 6 (step S7). Motorizing is a process in which the engine 10 is forcibly rotated by the first MG 14 with fuel injection stopped and the throttle valve 12v open. By motorizing the engine 10, air is supplied from the engine 10 to the catalyst 12c via the exhaust pipe 11e. This promotes the cooling of the catalyst 12c. In addition, as described above, driving the fan 6 also promotes the cooling of the catalyst 12c. In this case, the ECU 100 does not stop but maintains its running state. Step S7 is an example of the process performed by the motoring control unit and the fan control unit.

[0034] Next, the ECU 100 determines whether the power switch 71 is in a ready state (step S8). The ready state is when there is a request to start the engine system 1, as described above. If the answer in step S8 is Yes, the ECU 100 starts the engine 10 (step S9). In this case, the start of the engine 10 does not correspond to the "first start" of the engine 10 after the ECU 100 has started. Therefore, the engine 10 starts without performing a warm-up process. In this way, if it is predicted that the catalyst 12c will overheat, the engine 10 starts without performing a warm-up process. As a result, overheating of the catalyst 12c is suppressed.

[0035] If the answer in step S8 is No, the ECU 100 executes the processing from step S3 onwards. Furthermore, when estimating the temperature of the catalyst 12c while the engine 10 is motoring or the fan 6 is running, it is desirable to estimate the temperature of the catalyst 12c while considering the operation of the motoring and fan 6. For example, if the motoring and fan 6 are running, then... do not have Compared to other cases, it is desirable to estimate the temperature of catalyst 12c by assuming that the rate of temperature decrease of catalyst 12c while engine 10 is stopped is high.

[0036] Therefore, unless the judgment result is positive and the system enters a ready state, the motoring of the engine 10 and the operation of the fan 6 continue. This promotes the cooling of the catalyst 12c, and if it is predicted that the catalyst 12c will not overheat (No in step S5), the ECU 100 stops (step S6). In this way, by stopping the ECU 100 when the judgment result is negative, even if a warm-up process is performed when the engine 10 is started for the first time after the next start of the ECU 100, overheating of the catalyst 12c is suppressed.

[0037] Figures 4 to 7 are timing charts illustrating overheat suppression control. Figures 4 to 7 show the changes in the startup / shutdown state of the ECU 100, the ready-on / off state, the coolant temperature, the engine speed, the warm-up process execution state, and the temperature of the catalyst 12c. The actual temperature of the catalyst 12c is shown by a solid line, and the estimated temperature is shown by a dotted line. The overheat temperature T4 is the lowest temperature indicating that the catalyst 12c is in an overheated state, and is higher than the warm-up temperature T3.

[0038] Figure 4 is a timing chart for the case where the judgment result is positive and then the system becomes ready. When the coolant temperature at the time of the first start of the engine 10 after the ECU 100 is started is below the cold temperature T1, the warm-up process is performed (time t1). When the estimated catalyst temperature rises above the warm-up temperature T3, the warm-up process is stopped (time t2). After that, the system becomes ready off and the engine 10 stops, but the ECU 100 does not stop (time t3). At the time of ready off, the estimated catalyst temperature is above the limit temperature T2 and the coolant temperature is below the cold temperature T1. Therefore, if the ECU 100 is stopped, it is predicted that the warm-up process will be performed at the time of the first start of the engine 10 after the next start of the ECU 100, and the catalyst 12c will overheat (Yes in step S5).

[0039] Subsequently, the system enters a ready-on state and engine 10 starts, but the warm-up process is not performed (time t4, step S8: Yes, step S9). This is because this start does not correspond to the first start after ECU 100 has been activated.

[0040] In Figure 4, the dashed line shows the case where the ECU 100 is stopped at time t3 and started at time t4 to perform the warm-up process. If the warm-up process is performed at time t4, the actual temperature of the catalyst 12c will exceed the overheating temperature T4 (time t5). In this embodiment, even when the ready-off state is reached, the ECU 100 maintains its running state, allowing the engine 10 to start without performing the warm-up process when the ready-on state is reached. In this way, overheating of the catalyst 12c is suppressed. In the example in Figure 4, the engine 10 is motored and the fan 6 is driven from time t3 to time t4.

[0041] Figure 5 is a timing chart showing the case where the judgment result changes from a positive to a negative. The warm-up process is performed (time t1) and then stopped (time t2). Subsequently, the engine 10 stops in a ready-off state, but the ECU 100 does not stop (time t3). This is because, as in the case of Figure 4, it is predicted that the catalyst 12c will overheat (Yes in step S5).

[0042] Subsequently, the estimated catalyst temperature falls below the limit temperature T2, and the ECU 100 stops (time t4, step S6). This is because it is predicted that the catalyst 12c will not overheat even if a warm-up process is performed during the first start of the engine 10 after the next start of the ECU 100 (No in step S5). In this way, overheating of the catalyst 12c is suppressed. In addition, in the example of Figure 5, the motoring of the engine 10 and the operation of the fan 6 are performed from time t3 to time t4.

[0043] Figure 6 is a timing chart showing the case where the judgment result is negative. The warm-up process is performed (time t1) and stopped (time t2). After that, the engine 10 stops in a ready-off state, and the ECU 100 also stops (time t3, step S6). At the ready-off state, the coolant temperature is higher than the cold temperature T1. Therefore, it is predicted that the warm-up process will not be performed when the engine 10 is started for the first time after the next start of the ECU 100 (No in step S5). After that, the ECU 100 starts up in a ready-on state and the engine 10 starts, but since the coolant temperature is higher than the cold temperature T1, the warm-up process is not performed (time t4). In this way, the warm-up process is avoided, and the overheating of the catalyst 12c is suppressed.

[0044] Furthermore, as shown in Figure 6, the catalyst temperature is not estimated while the ECU 100 is stopped. Also, as shown in Figure 6, the estimated catalyst temperature at the time of ECU 100 startup may deviate from the actual temperature. In this embodiment, the catalyst temperature at the time of ECU 100 startup is estimated based on the coolant temperature at startup, as it is correlated with the coolant temperature at startup. In other words, at the time of ECU 100 startup, the effect of the exhaust heat from the engine 10 that the catalyst 12c has received up to that point is not taken into consideration, and the catalyst temperature is estimated based on the coolant temperature. For this reason, for example, if the decision to perform a warm-up treatment is made based on the estimated catalyst temperature at the time of ECU 100 startup, the warm-up treatment may be performed at time t4 in Figure 6, and the catalyst 12c may overheat. In this embodiment, since the decision to perform a warm-up treatment is made based on the coolant temperature at the time of ECU 100 startup, overheating of the catalyst 12c is suppressed.

[0045] Figure 7 is a timing chart showing the case where the judgment result is negative and the warm-up process is performed during the subsequent ready-on state. The warm-up process is performed (time t1) and then stops (time t2). After that, the engine 10 stops in the ready-off state, and the ECU 100 also stops (time t3, step S6). This is because, at the ready-off state, the coolant temperature is higher than the cold temperature T1, and it is predicted that the warm-up process will not be performed during the first start of the engine 10 after the next start of the ECU 100 (No in step S5).

[0046] Subsequently, when the ECU 100 is activated by the "Radion" button and the engine 10 starts, a warm-up process is performed (time t4). This is because the coolant temperature is below the cold temperature T1. After that, the warm-up process stops (time t5). In this way, when the "Radion" state is reached after the coolant temperature has dropped sufficiently, the warm-up process is performed to reduce exhaust emissions. Furthermore, when the coolant temperature is below the cold temperature T1, the actual temperature of the catalyst 12c also falls below the limit temperature T2, so even if the warm-up process is performed, overheating of the catalyst 12c is suppressed. Also, at time t4, for the reasons mentioned above, the estimated catalyst temperature at the time of ECU 100's activation deviates from the actual temperature.

[0047] As described above, the judgment process is executed again until the judgment result is negative, in which case the ECU 100 stops. In this case, as shown in Figure 7, the warm-up process is executed if the temperature of the engine 10 at the first start of the engine 10 after the ECU 100 has started is below the cold temperature. As described above, it is not necessary to estimate the temperature of the catalyst 12c at the next engine start in order to determine whether or not to execute the warm-up process at the next start of the engine 10. For this reason, it is not necessary to measure the engine 10 stop period or to obtain the outside temperature during the engine 10 stop period. Control is simplified in this way.

[0048] Furthermore, as mentioned above, the determination process is performed based on the coolant temperature at the ready-off point and the estimated catalyst temperature. This simple control allows for the prediction of whether or not overheating will occur.

[0049] In the above embodiment, an engine system 1 mounted on a hybrid vehicle was described as an example, but the invention is not limited to this, and an engine system mounted on a conventional engine vehicle may also be used. However, in this case, the engine 10 cannot be motorized. In the above embodiment, when overheating of the catalyst 12c was predicted, the engine 10 was motorized and the fan 6 was driven, but either one or the other may be performed. In the above embodiment, the temperature of the coolant was described as an example of the temperature of the engine 10, but the temperature of the lubricating oil may also be used as the temperature of the engine 10.

[0050] Although embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]

[0051] 1. Engine System 5. Radiator 6 Fans 10 Engines 12c catalyst 14. First Motor Generator 100 ECUs (Control unit, engine control unit, detection unit, estimation unit, determination unit, stop unit, motoring control unit, fan control unit)

Claims

1. A control device for an engine system having an engine and a catalyst for purifying the exhaust gas of the engine, An engine control unit that, when the engine temperature is below the cold temperature during the first start of the engine after the control device has been started, starts the engine and performs a warm-up process to raise the catalyst temperature to the warm-up temperature, and stops the engine when there is a request to stop the engine system, When the aforementioned stop request is made, a detection unit detects the temperature of the engine, When a stop request is made, an estimation unit estimates the temperature of the catalyst based on the operating state of the engine from the time the engine is started until the stop request is made, When the aforementioned stop request is made, a determination unit performs a determination process based on the engine temperature and the catalyst temperature to predict whether the warm-up process will be performed and whether the catalyst will overheat when the engine is first started after the next startup of the control device, The control device is further comprising a stop unit that stops the control device based on the determination result of the determination unit, If the determination result is negative, the stop unit stops the control device. If the result of the determination is positive, the determination unit re-executes the determination process. If the determination result is positive and there is a request to start the engine system, the engine control unit starts the engine without performing the warm-up process. If the result of the re-execution of the determination process is a negative determination, the stop unit stops the control device. If the aforementioned stop request is made, and the engine temperature is below the cold temperature and the catalyst temperature is above a limit temperature lower than the warm-up temperature, the determination unit makes a positive determination. If a stop request is made, and the engine temperature is higher than the cold temperature or the catalyst temperature is below the limit temperature, the determination unit makes a negative determination. The aforementioned limiting temperature is the temperature at which the catalyst overheats due to the warm-up process performed during the first engine start-up after the next startup of the control device. If the aforementioned stop request exists and the engine temperature is higher than the cold temperature, the determination unit predicts that the warm-up process will not be performed when the engine is first started after the control device is activated, and makes the negative determination. In the event of the aforementioned stop request and the temperature of the catalyst is below the limit temperature, the determination unit predicts that the catalyst will not overheat even if the warm-up process is performed during the first engine start after the control device is started, and makes the aforementioned denial determination, an engine system control device.

2. The engine system has a motor that motors the engine with fuel injection stopped and the throttle valve open. A control device for an engine system according to claim 1, comprising a motoring control unit that performs motoring of the engine by the motor when the determination result is a positive determination.

3. The engine system includes a radiator for cooling the engine's coolant and a fan for cooling the radiator and the catalyst. A control device for an engine system according to claim 1, comprising a fan control unit that drives the fan when the determination result is a positive determination.

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