Control device for hybrid vehicle

Abstract

To avoid or reduce incomplete warm-up of an engine in a hybrid vehicle.SOLUTION: A control device executes processing of counting the number of times that the hybrid vehicle is started and stopped before warm-up of an engine is completed as the number of times of incomplete warm-up. In addition, when the hybrid vehicle is started, the control device executes processing of setting at least one of a start threshold and a stop threshold for the engine in accordance with the counted number of times of incomplete warm-up. In addition, the control device executes processing of starting the engine when a request output for the engine exceeds the set start threshold and stopping the engine when the request output falls below the set stop threshold. When a predetermined time elapses after warm-up of the engine is completed with the hybrid vehicle started, the control device executes processing of subtracting or clearing the counted number of times of incomplete warm-up.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present specification relates to a control device for a hybrid vehicle. [Background technology]

[0002] Patent Document 1 describes a technique related to warming up an engine mounted on a vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-167858 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of a hybrid vehicle, the engine is repeatedly started and stopped depending on the required output of the engine. Therefore, it takes a relatively long time for the engine to warm up, and the use of the hybrid vehicle may be terminated before the engine has completely warmed up. Such incomplete warming up may have a negative effect on the engine, etc. (including the oil and fuel).

[0005] In view of the above, the present specification provides a technique that can avoid or suppress incomplete warm-up of the engine in a hybrid vehicle. [Means for solving the problem]

[0006] The technology disclosed in this specification is embodied in a control device for a hybrid vehicle. The control device executes a process of counting the number of times the hybrid vehicle is started and stopped (also called ready-off) before the warm-up of the engine is completed as the number of incomplete warm-ups. In addition, when the hybrid vehicle is started, the control device executes a process of setting at least one of a start threshold and a stop threshold for the engine according to the counted number of incomplete warm-ups. In addition, the control device executes a process of starting the engine when the required output for the engine exceeds the set start threshold, and of stopping the engine when the required output falls below the set stop threshold. When a predetermined time has passed since the warm-up of the engine is completed while the hybrid vehicle is started, the control device executes a process of subtracting or clearing the counted number of incomplete warm-ups.

[0007] In the above-mentioned configuration, the control device can change the conditions for starting / stopping the engine (i.e., the start threshold and / or the stop threshold) according to the number of incomplete warm-ups. For example, when the number of incomplete warm-ups is high, the control device can adjust each threshold to lower the start threshold for the engine or raise the stop threshold for the engine. This can increase the number of engine starts and the start time, thereby facilitating engine warm-up. On the other hand, when the usage mode of the hybrid vehicle by the user is changed, for example, it is assumed that the start threshold and / or the stop threshold adjusted according to the previous usage mode may be excessive for the new usage mode. Therefore, the control device is configured to subtract or clear the counted number of incomplete warm-ups when the use of the hybrid vehicle is continued for a predetermined time after the warm-up of the engine is completed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing a configuration of a hybrid vehicle. [Diagram 2] 4 is a flowchart showing an example of a series of processing procedures executed by a control device. [Diagram 3]FIG. 13 is a diagram illustrating a start threshold value. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A control device 30 for a hybrid vehicle 10 of an embodiment will be described with reference to the drawings. A hybrid vehicle refers to a vehicle in which the wheels are driven by the power of an engine and a driving motor. As an example, the control device 30 of the embodiment is mounted on the hybrid vehicle 10. However, in other embodiments, the control device 30 does not have to be mounted on the hybrid vehicle 10, and may be disposed outside the hybrid vehicle 10 and control the hybrid vehicle 10 remotely.

[0010] 1, a hybrid vehicle 10 (hereinafter simply referred to as vehicle 10) includes, in addition to the above-mentioned control device 30, a vehicle body 12, a plurality of wheels 14, 16, an engine 18, a first motor 20, a second motor 22, a power split mechanism 24, a gear unit 26, a battery 28, and a temperature sensor 32. The plurality of wheels 14, 16 include a pair of front wheels 14 provided at the front of the vehicle body 12, and a pair of rear wheels 16 provided at the rear of the vehicle body 12. Note that the specific configuration of the vehicle body 12 and the number of wheels provided on the vehicle 10 are not particularly limited.

[0011] The engine 18 is a heat engine that generates power by burning fuel, and examples of the engine 18 include, but are not limited to, a gasoline engine, a diesel engine, etc. A temperature sensor 32 is disposed near the engine 18. The temperature sensor 32 is a sensor for monitoring the temperature of the engine 18, and specifically, detects the temperature of the cooling water for cooling the engine 18. The cooling water circulates through a cooling path that passes through the engine 18 and a radiator (not shown).

[0012] The power split mechanism 24 is mechanically connected to the engine 18. The power split mechanism 24 is mechanically connected to the first motor 20 and the second motor 22. The power split mechanism 24 distributes the power of the engine 18 to the first motor 20 and the second motor 22 (i.e., the pair of front wheels 14).

[0013] The first motor 20 is mechanically connected to the engine 18 via a power split mechanism 24, and functions as a generator. That is, the hybrid vehicle 10 can generate power by using the first motor 20 to drive the first motor 20 with the engine 18. The first motor 20 is electrically connected to a battery 28, and the power generated by the first motor 20 is supplied to the battery 28 to charge the battery 28. The engine 18 is mechanically connected to the second motor 22 via the power split mechanism 24.

[0014] The second motor 22 is mechanically connected to the engine 18 via a power split mechanism 24. The second motor 22 is electrically connected to a battery 28 and operates by receiving power supply from the battery 28. The second motor 22 is mechanically connected to the front wheels 14 via a gear unit 26 and functions as a prime mover that drives the front wheels 14. That is, the rotational motion (i.e., torque) output by the second motor 22 is distributed to the pair of front wheels 14 via the gear unit 26. The second motor 22 can also function as a generator for regenerative braking of the front wheels 14, in addition to the prime mover. That is, when the vehicle 10 needs to decelerate, the second motor 22 can function as a generator to perform regenerative braking of the front wheels 14. It should be noted that the second motor 22 may drive the rear wheels 16 as drive wheels instead of the front wheels 14.

[0015] The battery 28 is connected to the first motor 20 and the second motor 22. The battery 28 is a power supply device for the second motor 22, and supplies driving power to the second motor 22. The battery 28 has a plurality of secondary battery cells, and is configured to be capable of repeated charging and discharging. The secondary battery cells referred to here are not particularly limited, and may be, for example, lithium ion battery cells or nickel metal hydride battery cells. Although not shown, power conversion devices may be provided between the battery 28 and the first motor 20, and between the battery 28 and the second motor 22, respectively, as necessary.

[0016] The control device 30 is configured using a computer device, and has a processor, a memory, and the like. The control device 30 is electrically connected to the engine 18, the battery 28, and the gear unit 26, and is configured to be able to control the operations of these. The control device 30 is further connected to a temperature sensor 32 so as to be able to communicate with them. For example, operation information by a user and vehicle information indicating the state of the vehicle are input to the control device 30. The operation information includes output information required by the user for the engine 18, such as the amount of operation of the accelerator pedal and the amount of operation of the brake. The vehicle information includes information indicating the state of the engine 18, such as the temperature detected by the temperature sensor 32, and ON / OFF information of a power switch (also called a ready switch or an ignition switch) of the vehicle 10.

[0017] When the vehicle 10 is started and stopped (also called ready-off) before the warm-up of the engine 18 is completed, the control device 30 cumulatively counts the number of times this occurs as the number of incomplete warm-ups. Here, "before the warm-up of the engine 18 is completed" refers to, for example, the temperature detected by the temperature sensor 32 being lower than a first predetermined temperature. The first predetermined temperature may be, for example, 80°C.

[0018] In addition, the control device 30 counts the number of incomplete warm-ups as a second number of incomplete warm-ups when the temperature detected by the temperature sensor 32 is lower than a second predetermined temperature. The second predetermined temperature may be lower than the first predetermined temperature, for example, 50°C. In other words, the second number of incomplete warm-ups means, among the number of incomplete warm-ups, the number of times that the vehicle 10 is started and stopped early without the vehicle 10 warming up progressing. The control device 30 controls the operation of each part of the vehicle 10 described above according to the input operation information, vehicle information, the number of incomplete warm-ups, etc.

[0019] 2 and 3, a series of processes related to warming up the engine 18 executed by the control device 30 will be described. The control device 30 is configured to execute a series of processes shown in FIG. 2 when the vehicle 10 is started (also called ready-on).

[0020] In step S12, the control device 30 reads the counted number of incomplete warm-ups.

[0021] In step S14, the control device 30 calculates a start threshold from the number of incomplete warm-ups in step S12. The start threshold is a threshold for starting the engine 18 according to the output required for the engine 18. That is, the control device 30 starts the engine 18 when the output required for the engine 18 exceeds the start threshold. As shown by the solid line A in FIG. 3, the control device 30 of this embodiment changes the start threshold set according to the number of incomplete warm-ups until the warm-up of the engine 18 is completed. Specifically, the start threshold is set to a smaller value as the number of incomplete warm-ups increases. That is, the engine 18 is more likely to start with respect to the output required for the engine 18. On the other hand, the dashed line B shown in FIG. 3 indicates the start threshold in the normal control process. The start threshold in the normal control process is constant regardless of the number of incomplete warm-ups.

[0022] In step S14, the control device 30 sets the start threshold according to the number of incomplete warm-ups, but instead of or in addition to this, the control device 30 may calculate a stop threshold for stopping the engine 18. That is, the control device 30 stops the engine 18 when the output required for the engine 18 falls below the stop threshold. Therefore, if the stop threshold is set to a larger value as the number of incomplete warm-ups increases, it becomes more difficult to stop the engine 18 in response to the output required for the engine 18.

[0023] In step S16, the control device 30 reads the second count of incomplete warm-up.

[0024] In step S18, the control device 30 judges whether the second incomplete warm-up count is equal to or greater than a predetermined value. If the second incomplete warm-up count is equal to or greater than the predetermined count (YES in S18), the control device 30 proceeds to the process of step S20. If not (NO in S18), the control device 30 skips the process of step S20 and proceeds to the process of step S22.

[0025] In step S20, the control device 30 executes a warm-up promotion control process. In the warm-up promotion control process, the operating state of the engine 18 is controlled to promote the warm-up of the engine 18. For example, the warm-up of the engine 18 is promoted by performing control to reduce the fuel efficiency of the engine 18, such as increasing the rotation speed of the engine 18.

[0026] In step S22, the control device 30 judges whether or not the warm-up of the engine 18 has been completed. The control device 30 judges that the warm-up has been completed, for example, when the temperature detected by the temperature sensor 32 is equal to or higher than a first predetermined temperature (for example, 80° C.). If the warm-up has been completed (YES in step S22), the control device 30 ends the warm-up promotion control process and proceeds to the process of step S24. If not (NO in step S22), the control device 30 continues the process of step S22 until the warm-up has been completed.

[0027] Although not shown, if it is detected that the power switch has been turned to the OFF state (i.e., ready-off) before the warm-up of the engine 18 is completed, the control device 30 adds to the counts of the number of incomplete warm-ups and the second number of incomplete warm-ups, and ends the series of processing or returns to the processing of step S12.

[0028] In step S24, the control device 30 executes the normal control process. As described above, in the normal control process, a constant value is set to the start threshold regardless of the number of incomplete warm-ups. That is, the control device 30 sets the start threshold based on the dashed line B in FIG. 3.

[0029] In step S26, the control device 30 judges whether the warm-up time of the engine 18 is equal to or longer than a predetermined time. The control device 30 judges that the warm-up time is equal to or longer than a predetermined time, for example, when the temperature detected by the temperature sensor 32 is maintained at 80° C. or higher for about 30 minutes. If the warm-up time is equal to or longer than the predetermined time (YES in S26), the control device 30 proceeds to the process of step S28. If not (NO in S26), the control device 30 returns to the process of step S24 and continues the normal control process.

[0030] In step S28, the control device 30 subtracts or clears the incomplete warm-up count and the second incomplete warm-up count. For example, when the manner in which the user uses the vehicle 10 (for example, the user's main driving route) is changed, it is possible to prevent the start threshold and / or the stop threshold adjusted according to the previous manner of use from becoming excessive for the new manner of use.

[0031] As a result, the control device 30 ends or repeats the process of executing a series of steps S12-S28. As described above, the control device 30 can change the conditions related to starting / stopping the engine 18 (i.e., the start threshold and / or the stop threshold) according to the number of incomplete warm-ups. For example, if the number of incomplete warm-ups is high, the control device 30 can adjust each threshold so as to lower the start threshold for the engine 18 or raise the stop threshold for the engine 18. This can increase the number of starts and the start time of the engine 18, facilitating warm-up of the engine.

[0032] The process of executing the series of steps S12-S28 described above is one example. The control device 30 does not need to execute the processes of steps S16-S24, for example. That is, the warm-up promotion control process based on the second incomplete warm-up count is an optional additional process. [Explanation of symbols]

[0033] 10: Hybrid vehicle (vehicle), 18: Engine, 30: Control device

Claims

[Claim 1] A control device for a hybrid vehicle, A process of counting the number of times the hybrid vehicle is started and stopped before the engine has been completely warmed up as the number of times the engine has not been completely warmed up; a process of setting at least one of a start threshold and a stop threshold for the engine in accordance with the counted number of incomplete warm-ups when the hybrid vehicle is started; a process of starting the engine when a required output of the engine exceeds the set start threshold, and stopping the engine when the required output falls below the set stop threshold; a process of subtracting or clearing the counted number of incomplete warm-ups when a predetermined time has elapsed since the warm-up of the engine is completed while the hybrid vehicle is still running; A control device capable of executing the above.

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