Control device of vehicle

Abstract

To provide a control device of a vehicle which can quickly start an engine by a starter if the engine cannot be started by a motor.SOLUTION: A control device of a vehicle equipped with a motor connected to an engine, includes a control part which performs MG start-up control for starting the engine by the motor. The control part continues to output MG torque with which engine rotation can stop if MG torque for starting the engine is insufficient when performing the MG start-up control, and at the same time starts the engine by driving a starter when the engine rotation stops.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Patent Document 1 discloses a technique for starting an engine by using a motor and a starter in combination. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-193935 A Summary of the Invention [Problem to be solved by the invention]

[0004] There has been a demand for technology that can quickly start the engine using a starter when the engine cannot be started using a motor.

[0005] The present disclosure has been made in consideration of the above, and has an object to provide a vehicle control device that can quickly start the engine using a starter when the engine cannot be started using a motor. [Means for solving the problem]

[0006] The vehicle control device of the present disclosure is a control device for a vehicle having a motor connected to an engine, and includes a control unit that performs MG start control to start the engine using the motor, and when the MG torque for starting the engine is insufficient during the MG start control, the control unit continues to output MG torque capable of stopping engine rotation, and when engine rotation has stopped, drives the starter to start the engine. Effect of the Invention

[0007] In the present disclosure, instead of removing the MG torque when engine starting by the motor fails, the MG torque is balanced with the engine compression reaction force until the starter starts to drive (the engine stops rotating), thereby improving engagement when the starter is driven and shortening the time until the engine starts. Therefore, according to the present disclosure, when the engine cannot be started by the motor, the engine can be started quickly by the starter. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a vehicle to which a vehicle control device according to an embodiment is applied. [Diagram 2] FIG. 2 is a schematic diagram for explaining adjustment of the MG torque in the control device for the vehicle according to the embodiment. [Diagram 3] FIG. 3 is a time chart showing a flow of control executed by the control device for the vehicle according to the embodiment. [Figure 4] FIG. 4 is a flowchart showing a flow of control executed by the control device for the vehicle according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A vehicle control device according to an embodiment of the present disclosure will be described with reference to the drawings. Note that components in the following embodiments include those that are easily replaceable by a person skilled in the art, or those that are substantially the same.

[0010] (Vehicle control device) The configuration of a vehicle control device according to an embodiment will be described with reference to Fig. 1. The vehicle control device according to the embodiment is applied to a vehicle equipped with a motor connected to an engine. Vehicles to which the vehicle control device according to the embodiment is applied include, for example, hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs).

[0011] 1, a vehicle to which the vehicle control device according to the embodiment is applied includes an engine 1, a motor (MG: Motor Generator) 2, a starter 3, and a control unit 4. Note that in the figure, only the components necessary to realize the vehicle control device according to the embodiment are extracted from the vehicle components and illustrated, and other components are omitted.

[0012] The engine 1 is an internal combustion engine such as a gasoline engine, a diesel engine, etc. A ring gear (flywheel ring gear) that meshes with a pinion gear of a starter 3 is attached to a crankshaft of the engine 1.

[0013] The motor 2 is, for example, an AC synchronous motor, and functions as an electric motor and a generator. The motor 2 functions as a power source for the vehicle, and also functions as a starting device for the engine 1. The motor 2 is connected to the crankshaft of the engine 1 via a belt. The motor 2 may be connected to the engine 1 via other connecting members, for example, via gears.

[0014] The starter (starter motor) 3 is a starting device for the engine 1. A pinion gear that meshes with a ring gear of the engine 1 is attached to the starter 3. The pinion gear of the starter 3 engages with the ring gear of the engine 1 when the starter 3 is driven.

[0015] The control unit 4 is an electronic control unit (ECU) whose main components are a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and executes various programs. The control unit 4 realizes functions that meet a predetermined purpose by controlling each component through the execution of the programs.

[0016] The control unit 4 performs MG start control to start the engine 1 using the motor 2. However, if the torque of the motor 2 (hereinafter referred to as "MG torque") becomes insufficient due to some factor and starting the engine 1 using the motor 2 fails, the control unit 4 switches to starting the engine 1 using the starter 3.

[0017] That is, when the MG torque for starting the engine 1 is insufficient during MG start control and starting of the engine 1 by the motor 2 fails, the control unit 4 continues to output the MG torque capable of stopping the engine rotation by the motor 2. Then, when the engine rotation has stopped, the control unit 4 drives the starter 3 to start the engine 1.

[0018] Here, when starting the engine 1 using the starter 3, it is necessary to drive the starter 3 while the engine is stopped (or rotating at a very low speed) in order to ensure meshing between the ring gear of the engine 1 and the pinion gear of the starter 3. In this case, if the motor 2 is stopped and the engine 1 is waited for to stop rotating, it takes time to start driving the starter 3, and the start of the engine 1 may be delayed, causing a sense of discomfort to the driver of the vehicle.

[0019] Therefore, when the control unit 4 determines that the MG torque for starting the engine 1 is insufficient and starting of the engine 1 by the motor 2 has failed, it does not completely stop the motor 2, but rather outputs from the motor 2 an MG torque that balances with the compression reaction force of the engine 1, as shown in Fig. 2 for example. This "MG torque that balances with the compression reaction force of the engine 1" refers to the above-mentioned "MG torque that can stop the engine rotation."

[0020] By adjusting the MG torque in this manner, the control unit 4 can quickly stop the rotation of the engine 1 when starting of the engine 1 by the motor 2 fails, as shown in Fig. 3. This allows the starter 3 to be driven early to start the engine 1 while ensuring meshing between the ring gear of the engine 1 and the pinion gear of the starter 3.

[0021] (Vehicle control method) An example of a vehicle control method executed by the vehicle control device according to the embodiment will be described with reference to FIG.

[0022] First, the control unit 4 determines whether the engine 1 is being started by the motor 2 (MG start control is being performed) (Step S1). If it is determined in Step S1 that the engine 1 is being started by the motor 2 (Yes in Step S1), the control unit 4 determines whether the engine 1 cannot be started by the motor 2 (MG torque is insufficient) (Step S2).

[0023] In step S2, a positive determination can be made in the following cases, for example. (1) When the engine speed increases slowly (2) If the engine speed drops during cranking (3) When the engine speed does not reach the specified speed even after MG torque is output for a certain period of time.

[0024] In step S2, when it is determined that starting of the engine 1 by the motor 2 is not possible (Yes in step S2), the control unit 4 adjusts the MG torque by the motor 2 so as to balance with the engine compression reaction force (step S3).

[0025] In step S3, the MG torque can be adjusted, for example, by the following method. (1) Check the engine speed and adjust the MG torque using feedback control. (2) The MG torque is determined in advance according to the crank angle of the engine 1 and adjusted.

[0026] Next, the control unit 4 determines whether or not the rotation of the engine 1 has stopped (step S4). Note that in step S4, even if the rotation of the engine 1 has not completely stopped, it is sufficient to determine that the rotation speed is within a range where the pinion gear of the starter 3 can mesh with the ring gear of the engine 1.

[0027] In step S4, when it is determined that the rotation of the engine 1 has stopped (Yes in step S4), the control unit 4 starts the engine 1 by driving the starter 3 (step S5), and then ends this process.

[0028] Here, if it is determined in step S1 that the engine 1 is not being started by the motor 2 (No in step S1), the control unit 4 completes this process. If it is determined in step S2 that starting the engine 1 by the motor 2 is not impossible (is possible) (No in step S2), the control unit 4 completes this process. If it is determined in step S4 that the rotation of the engine 1 has not stopped (No in step S4), the control unit 4 returns to the process of step S3.

[0029] The vehicle control device according to the embodiment described above monitors the starting state of the engine 1, and if it is determined that the MG torque from the motor 2 is insufficient to start the engine 1, it adjusts the MG torque to balance the MG torque with the compression reaction force of the engine 1. This stops the engine rotation. Then, after it is confirmed that the engine rotation has stopped, it drives the starter 3.

[0030] In this way, in the vehicle control device according to the embodiment, instead of removing the MG torque when starting of the engine 1 by the motor 2 fails, the MG torque is balanced with the engine compression reaction force until the starter 3 starts to drive (the engine stops rotating). This improves meshing when the starter 3 is driven, and shortens the time until the engine 1 starts. Therefore, according to the vehicle control device according to the embodiment, when the engine 1 cannot be started by the motor 2, the engine 1 can be quickly started by the starter 3.

[0031] In addition, according to the vehicle control device of the embodiment, delay in engine stop due to oscillation of engine compression reaction force is eliminated, and the engine rotation is quickly stopped, so that the timing at which the starter 3 begins to drive can be advanced (the start of the engine 1 can be advanced).

[0032] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0033] 1 Engine 2 Motors 3 Starter 4. Control Unit

Claims

[Claim 1] A control device for a vehicle having a motor connected to an engine, a control unit that performs MG start control to start the engine by the motor, When the MG torque for starting the engine is insufficient during the MG start control, the control unit continues to output the MG torque capable of stopping the engine rotation, and when the engine rotation has stopped, drives a starter to start the engine. Vehicle control device.

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