Control device

Abstract

To provide a control device capable of securing hydraulic pressure in an oil pump in BEV travelling.SOLUTION: A control device is applied to a vehicle equipped with: an internal combustion engine and a motor for outputting power for travelling; a generator capable of generating electric power by the power of the internal combustion engine; a power dividing mechanism for dividing and transmitting the power of the internal combustion engine to driving wheels and the generator; and an oil pump driven by the internal combustion engine. The control device is configured to drive the generator when the oil pump is rotated reversely while the internal combustion engine is stopped and travelling is executed by the power from the motor.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a control device. [Background technology]

[0002] Conventionally, there has been known a control device applied to a vehicle (see, for example, Patent Document 1). The vehicle includes an internal combustion engine and a motor that output power for running, a generator that can generate electricity using the power of the internal combustion engine, a power split mechanism that splits and transmits the power of the internal combustion engine to the drive wheels and the generator, and an oil pump that is driven by the internal combustion engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-154695 Summary of the Invention [Problem to be solved by the invention]

[0004] In the vehicle described above, when the internal combustion engine is stopped and the vehicle is running on power from the motor, if the oil pump rotates in reverse due to vibrations or the like caused by running, the oil pressure in the oil pump may drop. If the internal combustion engine is started with the oil pressure in the oil pump significantly lowered (when the drop in the oil pressure in the oil pump exceeds the allowable limit), there is a risk of abnormal noise being generated.

[0005] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a control device that can maintain oil pressure in an oil pump when driving a BEV. [Means for solving the problem]

[0006] The control device according to the present invention is applicable to a vehicle equipped with an internal combustion engine and a motor that output power for running, a generator capable of generating electricity using power from the internal combustion engine, a power split mechanism that splits and transmits the power of the internal combustion engine to the drive wheels and the generator, and an oil pump driven by the internal combustion engine. The control device is configured to drive the generator or start the internal combustion engine when the oil pump is rotated in reverse while the internal combustion engine is stopped and the vehicle is running using power from the motor. [Effects of the Invention]

[0007] According to the control device of the present invention, the oil pressure in the oil pump can be ensured when the vehicle is running as a BEV. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram for explaining a vehicle to which a control device is applied; [Figure 2] FIG. 2 is a block diagram for explaining the electrical configuration of the vehicle of FIG. [Figure 3] 3 is a flowchart for explaining the operation control performed by the control device of FIG. 2 when the vehicle is running. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will be described below.

[0010] First, a vehicle to which a control device 9 according to this embodiment is applied will be described with reference to FIGS.

[0011] The vehicle is a hybrid vehicle, and is provided with an internal combustion engine 1 and a motor 3 as power sources for traveling. As shown in Fig. 1, the vehicle is equipped with the internal combustion engine 1, a generator 2, the motor 3, a power split mechanism 4, a countershaft 5, and an oil pump 6.

[0012] The internal combustion engine 1 is configured to burn fuel to output power for traveling. The generator 2 functions primarily as a power generator, and also functions as an electric motor in certain circumstances. The generator 2 is capable of generating electricity using the power of the internal combustion engine 1, and functions as a starter motor when the internal combustion engine 1 is started. The motor 3 functions primarily as an electric motor, and also functions as a generator in certain circumstances. The motor 3 is configured to output power for traveling using electricity. A motor-side drive gear 31 is provided on the output shaft 3a of the motor 3.

[0013] The power split mechanism 4 is, for example, a planetary gear mechanism, and is configured to be able to split and transmit the power of the internal combustion engine 1 to drive wheels (not shown) and the generator 2. The power split mechanism 4 has: an externally toothed sun gear 4S that rotates at the center of multiple gear elements; an externally toothed pinion gear 4P that is in circumscribing (meshing) with the sun gear 4S and revolves around it while rotating on its own axis; an internally toothed ring gear 4R formed in a hollow annular shape to mesh with the pinion gear 4P; and a planetary carrier 4C that supports the pinion gear 4P and rotates on its own axis as the pinion gear 4P revolves.

[0014] The sun gear 4S is connected to the output shaft 2a of the generator 2, so that the sun gear 4S and the output shaft 2a rotate integrally. The planetary carrier 4C is connected to the output shaft 1a of the internal combustion engine 1, so that the planetary carrier 4C and the output shaft 1a rotate integrally. An engine-side drive gear 42 is provided on the ring gear 4R via a clutch 41.

[0015] A counter driven gear 51 is provided on the counter shaft 5, and the engine side drive gear 42 and the motor side drive gear 31 are meshed with the counter driven gear 51. In addition, the counter shaft 5 is connected to drive wheels via a differential device (not shown). Therefore, power output from at least one of the internal combustion engine 1 and the motor 3 is transmitted to the drive wheels via the counter shaft 5 and the like.

[0016] The oil pump 6 is provided to cool and lubricate the generator 2 and the motor 3 by circulating oil. The oil pump 6 is connected to the output shaft 1a and is configured to be driven by the internal combustion engine 1. Note that when the internal combustion engine 1 is stopped, the oil pump 6 can be driven by the generator 2.

[0017] As shown in FIG. 2, the vehicle includes inverters 71 and 72, a battery 8, and a control device 9.

[0018] The inverter 71 is disposed between the generator 2 and the battery 8, and is provided so that the control device 9 can control the generator 2. The inverter 71 converts AC current generated by the generator 2 using the power of the internal combustion engine 1 into DC current and outputs it to the battery 8, and also converts DC current supplied from the battery 8 into AC current to drive the generator 2.

[0019] The inverter 72 is disposed between the motor 3 and the battery 8 and is provided so that the control device 9 can control the motor 3. The inverter 72 converts the direct current supplied from the battery 8 into alternating current to drive the motor 3, and also converts the alternating current generated by the motor 3 during regenerative braking into direct current and outputs it to the battery 8.

[0020] The battery 8 is a chargeable and dischargeable high-voltage power supply, and is configured to supply power to drive the generator 2 and the motor 3, and to store the power generated by the generator 2 and the motor 3.

[0021] The control device 9 includes a calculation unit and a storage unit (not shown) and is configured to control the running of the vehicle. For example, the control device 9 is configured to perform operation control of the internal combustion engine 1, drive control of the generator 2 and the motor 3, cooperative control of the internal combustion engine 1, the generator 2, and the motor 3, etc.

[0022] An encoder 91 and resolvers 92 and 93 are connected to the control device 9, and their detection results are input thereto. The encoder 91 is provided to calculate the rotation speed of the output shaft 1a of the internal combustion engine 1. The resolver 92 is provided to calculate the rotation speed and rotation direction of the output shaft 2a of the generator 2. The resolver 93 is provided to calculate the rotation speed and rotation direction of the output shaft 3a of the motor 3. The control device 9 is also configured to be able to switch the state of the clutch 41 (see FIG. 1).

[0023] In this vehicle, the driving modes are set to HEV mode and BEV mode, and the driving mode of the vehicle is switched depending on, for example, the state of charge of the battery 8 and the driving state of the vehicle.

[0024] HEV mode is a mode in which the vehicle runs using the internal combustion engine 1 and the motor 3. In HEV mode, the clutch 41 is engaged, and power from the internal combustion engine 1 is transmitted to the countershaft 5. Power can also be output from the motor 3 to the countershaft 5, and power from the internal combustion engine 1 can be used to generate electricity in the generator 2. In other words, in HEV mode, the vehicle runs using the power output from the internal combustion engine 1 and the motor 3.

[0025] The BEV mode is a mode in which the vehicle runs using the motor 3 while the internal combustion engine 1 is stopped. In the BEV mode, the clutch 41 is released, and the generator 2 is not rotated by the motor 3, but is stopped together with the internal combustion engine 1. In the BEV mode, the vehicle runs using the power output from the motor 3. In the BEV mode, for example, the ring gear 4R is fixed to the case (not shown) by a brake (not shown).

[0026] Here, in BEV mode, the oil pump 6 is also stopped along with the internal combustion engine 1 and generator 2. In such BEV mode, if the oil pump 6 rotates in reverse due to vibrations or the like associated with driving, the oil pressure in the oil pump 6 may decrease. This oil pressure in the oil pump 6 is the oil pressure in the discharge-side space (the space that communicates with the discharge pipe connected to the discharge hole of the oil pump 6). Note that in BEV mode, when the output shaft 1a rotates together with the oil pump 6, the output shaft 2a rotates at a predetermined ratio.

[0027] Therefore, the control device 9 is configured to drive the generator 2 when the oil pump 6 is rotated in reverse in the BEV mode. This drives the oil pump 6, making it possible to ensure the oil pressure in the oil pump 6.

[0028] Specifically, the control device 9 is configured to drive the oil pump 6 by the generator 2 when the reverse rotation speed of the generator 2 exceeds a threshold value in the BEV mode. This threshold value is, for example, an allowable limit for reverse rotation of the generator 2, and is set in advance based on an allowable limit for reverse rotation of the oil pump 6 (an allowable limit for a drop in oil pressure in the oil pump 6). This is because the encoder 91 cannot determine the rotation direction of the oil pump 6 (the output shaft 1a of the internal combustion engine 1), so the resolver 92 is used to determine whether the oil pump 6 is rotating reversely.

[0029] -Operation control while vehicle is running- Next, operation control performed by the control device 9 of this embodiment when the vehicle is traveling will be described with reference to Fig. 3. The following flow is repeated at predetermined time intervals. Each of the following steps is executed by the control device 9.

[0030] First, in step S1 of Fig. 3, it is determined whether the driving mode is BEV mode. That is, it is determined whether the vehicle is traveling using the motor 3 with the internal combustion engine 1 stopped. If it is determined that the vehicle is in BEV mode, the process proceeds to step S2. On the other hand, if it is determined that the vehicle is not in BEV mode (if it is in HEV mode), the process proceeds to END.

[0031] Next, in step S2, it is determined whether the reverse rotation speed of the generator 2 has exceeded a threshold value. Note that the generator 2 rotates in BEV mode due to vibrations associated with driving, etc. The reverse rotation speed of the generator 2 is calculated based on the detection result of the resolver 92. If it is determined that the reverse rotation speed of the generator 2 has exceeded the threshold value, the allowable limit for the drop in oil pressure in the oil pump 6 has been reached, and the process proceeds to step S3. On the other hand, if it is determined that the reverse rotation speed of the generator 2 has not exceeded the threshold value (if the generator 2 is not rotating in reverse, or if the generator 2 is rotating in reverse but the reverse rotation speed is less than the threshold value), the process returns to step S1. In other words, the process waits until the reverse rotation speed of the generator 2 exceeds the threshold value.

[0032] Next, in step S3, the generator 2 is driven, thereby driving the oil pump 6. That is, the generator 2 rotates the output shaft 1a of the internal combustion engine 1, thereby rotating the oil pump 6 in the forward direction. As a result, the oil pressure in the oil pump 6 increases.

[0033] Next, in step S4, it is determined whether or not the oil pressure in the oil pump 6 is secured. For example, if the driving of the generator 2 has continued for a predetermined period of time, it is determined that the oil pressure in the oil pump 6 is secured. If it is determined that the oil pressure in the oil pump 6 is secured, the generator 2 is stopped and the process moves to END. On the other hand, if it is determined that the oil pressure in the oil pump 6 is not secured, the process returns to step S3. In other words, the driving of the generator 2 continues until the oil pressure in the oil pump 6 is secured.

[0034] -effect- In this embodiment, as described above, when the oil pump 6 is rotated in reverse in the BEV mode, the generator 2 is driven to drive the oil pump 6, thereby ensuring the oil pressure in the oil pump 6. As a result, the oil pressure in the oil pump 6 is not significantly reduced, and the generation of abnormal noise when the internal combustion engine 1 is started can be suppressed.

[0035] In this embodiment, the resolver 92 is used to determine whether the oil pump 6 is rotating in the reverse direction.

[0036] -Other embodiments- It should be noted that the embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention should not be interpreted solely by the above-described embodiments, but should be defined by the claims. The technical scope of the present invention also includes all modifications within the scope and meaning equivalent to the claims.

[0037] For example, in the above embodiment, the generator 2 is driven when the reverse rotation speed of the generator 2 exceeds a threshold value in the BEV mode, but this is not limiting. The internal combustion engine may be started when the reverse rotation speed of the generator exceeds a threshold value in the BEV mode. Even in this case, the oil pump is driven, so the oil pressure in the oil pump can be ensured.

[0038] In addition, in step S1 of the above embodiment, an example is shown in which it is determined whether or not the vehicle is in BEV mode, and if so, the process proceeds to step S2. However, this is not limited to this, and it may be determined whether or not the driving time in BEV mode is equal to or greater than a predetermined value, and if the driving time in BEV mode is equal to or greater than the predetermined value, the process proceeds to step S2.

[0039] In addition, in step S2 of the above embodiment, an example has been shown in which it is determined whether the reverse rotation speed of the generator 2 has exceeded a threshold value, and if the reverse rotation speed of the generator 2 has exceeded the threshold value, the process proceeds to step S3. However, this is not limiting, and it may be determined whether the duration of the reverse rotation of the generator is equal to or greater than a predetermined value, and if the duration of the reverse rotation of the generator is equal to or greater than the predetermined value, the process proceeds to step S3. [Explanation of symbols]

[0040] 1... internal combustion engine, 2... generator, 3... motor, 4... power split mechanism, 6...Oil pump, 9...Control device

Claims

[Claim 1] A control device applied to a vehicle including an internal combustion engine and a motor that output power for driving, a generator that generates electricity using power from the internal combustion engine, a power split mechanism that splits and transmits the power of the internal combustion engine to drive wheels and the generator, and an oil pump driven by the internal combustion engine, a control device configured to drive the generator or start the internal combustion engine when the oil pump is rotated in reverse while the internal combustion engine is stopped and the vehicle is traveling using power from the motor.

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