JP2010228672A - Vehicle system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly and quickly determine shortage of driving force at the start of a vehicle and start an internal combustion engine in a vehicle system having a travel mode for traveling by driving only a motor at the start from a stop state where the internal combustion engine of the vehicle having the internal combustion engine and the motor as drive sources is stopped. <P>SOLUTION: The vehicle system includes: a fluid clutch for transmitting the driving force output from the motor to a transmission input shaft; and a control unit for selecting the motor travel mode according to a vehicle state, starting driving the motor, and starting the internal combustion engine when the input shaft rotational number of the transmission does not exceed a predetermined value in spite of elapse of the prescribed time or longer after driving the motor. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle system, and more particularly, to a vehicle system including an internal combustion engine and a motor as drive sources.

  Patent Document 1 includes an internal combustion engine and a motor as a drive source, and a vehicle (hybrid) having a motor use travel mode that travels using only the motor as a drive source and an engine use travel mode that travels while including the engine as a power source. A vehicle start-up engine start control device is disclosed. The starting engine start control device described in the publication estimates the minimum driving torque required for starting from the relationship between the brake torque, motor generator torque, and vehicle speed during the brake release transition period, and then depresses the accelerator based on that value. Before starting the operation, it is determined whether the engine has been started. Thereby, it is said that the amount of reverse of the vehicle can be suppressed when starting on a steep slope.

JP 2007-230288 A

  However, in the method of Patent Document 1 described above, the condition for starting the engine is that the vehicle speed sensor has detected the reverse of the vehicle. Therefore, when the vehicle is stationary due to a balanced driving force, such as when starting a slope, Since it does not switch to the engine use travel mode, there is a problem that the vehicle cannot move forward without waiting for an access stepping operation.

  Further, even when the driving force of the motor exceeds the minimum driving torque and moves forward, there is a problem that the vehicle speed does not increase when the road surface gradient and the road surface resistance are large.

  On the other hand, as mentioned in Patent Document 1, fuel efficiency is an important item in this type of vehicle system, and there is a demand to avoid starting the internal combustion engine as much as possible.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to drive only a motor when starting from a stop state in which the internal combustion engine of a vehicle including an internal combustion engine and a motor as a drive source is stopped. Another object of the present invention is to provide a vehicle system capable of accurately and promptly determining the lack of driving force at the time of starting in a vehicle system having a traveling mode for traveling and starting an internal combustion engine.

  According to a first aspect of the present invention, there is provided an internal combustion engine and a motor as drive sources, and a motor travel mode in which only the motor is driven to travel when starting from a vehicle stop state in which the internal combustion engine is stopped. A vehicle system, wherein a fluid clutch that transmits a driving force output from the motor to a transmission input shaft, and the motor travel mode is selected according to a vehicle state, and driving of the motor is started. A vehicle system comprising: a control unit that starts the internal combustion engine when the input shaft rotation speed of the transmission does not exceed a predetermined value even after a predetermined time has elapsed after driving. Provided.

  According to the present invention, it is possible to accurately and promptly determine the shortage of driving force at the time of starting from the stop state where the internal combustion engine is stopped, and to start the internal combustion engine. This is because it is configured to determine whether or not the driving force is sufficient using the rotation speed of the transmission input shaft input via the torque converter.

1 is a diagram illustrating a schematic configuration of a vehicle system according to a first embodiment of the present invention. It is a figure showing the structure of the control system of the vehicle system which concerns on the 1st Embodiment of this invention. It is a flowchart showing operation | movement of the vehicle system which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the engine starting conditions of the vehicle system which concerns on the 1st Embodiment of this invention. It is a figure showing the structure of the control system of the vehicle system which concerns on the deformation | transformation embodiment of this invention. It is a figure for demonstrating the deformation | transformation embodiment of this invention.

[First Embodiment]
Next, a first embodiment of the present invention using a torque converter as a fluid clutch will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an example of a vehicle system to which the present invention can be applied. Referring to FIG. 1, the vehicle system includes an engine 10, a motor generator 20, and a transmission 40 that transmits a driving force input via a torque converter 30 to a propeller shaft 52 at a predetermined speed ratio. It is prepared for.

  The crankshaft of the engine 10 is connected to the rotating shaft of the motor generator 20 via the engine disconnection clutch 50. By connecting and disconnecting the engine disconnection clutch 50, the engine is disconnected and the motor is operated in a power running mode. It is possible to switch between a motor traveling mode (EV traveling mode) that travels by the above and a hybrid mode that mainly drives the engine 10 and that appropriately performs a torque absorbing action or a torque adding action by the motor generator 20.

  FIG. 2 is a diagram showing the configuration of the control system of the vehicle system according to the first embodiment of the present invention. A thick line in FIG. 2 represents a power line, and a thin arrow line represents a signal line.

  Referring to FIG. 2, an engine ECU 60 that controls the engine 10, a battery ECU 62 that manages the state of charge of the battery, and the like, an M / G-ECU 66 that controls the power running / regenerative operation of the motor generator 20 via the inverter 72, An AT-ECU 68 for controlling the transmission (A / T) 40 and the engine disconnecting clutch 50 and an HV-ECU 64 for controlling these ECU groups are shown.

  Further, a transmission input shaft rotational speed sensor 41 that detects the rotational speed of the input shaft of the transmission 40 is provided.

  The HV-ECU 64 determines whether or not the engine needs to be started based on the input shaft speed of the transmission 40 from the transmission input shaft speed sensor 41 and instructs the engine ECU 60 to start the engine. Specifically, the HV-ECU 64 selects the motor travel mode (EV travel mode) when starting from a vehicle stop state in which the engine is stopped, and the input of the transmission 40 is performed even if a predetermined time (Th_T) has elapsed. If the shaft rotational speed does not exceed the predetermined threshold value (TH_N), the engine ECU 60 is instructed to start the engine.

  Next, the operation of this embodiment will be described in detail with reference to the drawings. FIG. 3 shows that the HV-ECU 64 of the vehicle system according to the first embodiment of the present invention selects a motor travel mode (EV travel mode) in order to start from a vehicle stop state where the engine is stopped, and M / G- It is a flowchart showing the process performed by predetermined time interval, after instruct | indicating power running operation with respect to ECU66.

  Referring to FIG. 3, the HV-ECU 64 includes an elapsed time (Tev) after instructing the M / G-ECU 66 to perform power running, and an input value (Nat; transmission) from the transmission input shaft rotational speed sensor 41. The input shaft rotation number) is monitored (step S001).

  The HV-ECU 64 determines whether or not an elapsed time (Tev) from instructing the power running operation to the M / G-ECU 66 exceeds a predetermined threshold value (Th_T) (step S002). This threshold value (Th_T) is the shortest determination time from when the M / G-ECU 66 is instructed to perform power running to when the engine is started when the driving force is insufficient.

  Here, when the elapsed time (Tev) after instructing the power running operation to the M / G-ECU 66 exceeds a predetermined threshold value (Th_T) (“YES” in step S002), the HV-ECU 64 Then, it is determined whether or not the transmission input shaft rotational speed (Nat) input from the transmission input shaft rotational speed sensor 41 exceeds a predetermined threshold value (Th_N) (step S003).

  Here, when the transmission input shaft rotational speed (Nat) input from the transmission input shaft rotational speed sensor 41 does not exceed a predetermined threshold value (Th_N), the HV-ECU 64 engages the clutch, The AT-ECU 68 and the engine ECU 60 are each instructed to start the engine (step S004).

  FIG. 4 is a diagram for explaining engine start conditions according to the first embodiment of the present invention. When the motor travel mode (EV travel mode) is selected in order to start from the vehicle stop state where the engine is stopped, and the M / G-ECU 66 is instructed to perform a power running operation (“EV travel start” in FIG. 4), the motor is driven. Accordingly, the torque is transmitted through the torque converter 30 and the transmission input shaft rotational speed Nat increases.

  When the driving force from the motor is less than the driving torque required for smooth starting, such as when starting from a steep uphill, as shown in FIG. It gradually increases.

  When the predetermined threshold value (Th_T) has elapsed and the transmission input shaft rotational speed Nat is equal to or less than the predetermined threshold value (Th_N), the HV-ECU 64 determines that the driving force is insufficient. Determination (“Driving power shortage determination” in FIG. 4), the motor drive is temporarily stopped, the clutch 50 is engaged, and the engine is started (“clutch engagement, engine start” in FIG. 4).

  If the driving force from the motor exceeds the driving torque required for a smooth start, such as when starting from a road with no gradient or a downhill, the transmission input at a larger gradient than in FIG. The shaft rotational speed Nat increases. Therefore, when the predetermined threshold value (Th_T) has elapsed, the transmission input shaft rotational speed Nat exceeds the predetermined threshold value (Th_N), so the engine is not started.

  As described above, according to the present embodiment, when the driving force of the engine is not necessary, the engine is prevented from starting, and when the engine driving force is required, the engine is started at an earlier timing. Is possible.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and further modifications, replacements, and replacements may be made without departing from the basic technical idea of the present invention. Adjustments can be made. For example, in the above-described embodiment, an example in which the present invention is applied to a vehicle system including a torque converter has been described. However, the present invention is applicable to any configuration in which the output of a motor is transmitted to a transmission input shaft via a fluid clutch. It is possible.

  Further, for example, as shown in FIG. 5, when the vehicle system is provided with a gradient sensor 74 or a weight sensor 76, a threshold value (Th_T) for determining whether to start the engine is set according to these values. You may adjust. For example, when starting from an extremely steep climb, the predetermined threshold value (Th_T) may be shortened or the engine may be started unconditionally. Similarly, when the vehicle starts from a stopped state where a load is loaded, the predetermined threshold value (Th_T) may be shortened or the engine may be started unconditionally.

  In the above-described embodiment, the configuration in which the engine and the motor are directly connected via the clutch has been described. However, the configuration in which the output of the other motor is transmitted to the transmission input shaft via the fluid clutch. If so, it is possible to apply.

  Further, in the above-described embodiment, it has been described that the motor drive is temporarily stopped when it is determined that the driving force is insufficient. However, when it is determined that the driving force is insufficient as illustrated in FIG. 6, the motor driving is continued. It is also possible to start the engine by engaging the clutch 50.

10 Engine 20 Motor generator (MG)
30 Torque converter 40 Transmission (A / T)
41 Transmission input shaft rotational speed sensor 50 Engine disconnection clutch 52 Propeller shaft 60 Engine ECU
62 Battery ECU
64 HV-ECU
66 M / G-ECU
68 AT-ECU
70 Battery 72 Inverter 74 Gradient sensor 76 Weight sensor

Claims (2)

A vehicle system having an internal combustion engine and a motor as a drive source, and having a motor travel mode that travels by driving only the motor when starting from a vehicle stop state in which the internal combustion engine is stopped,
A fluid clutch for transmitting a driving force output from the motor to a transmission input shaft;
The motor driving mode is selected according to the vehicle state, the driving of the motor is started, and the input shaft rotational speed of the transmission does not exceed a predetermined value even after a predetermined time has elapsed after the driving of the motor. A controller for starting the internal combustion engine;
A vehicle system comprising: In addition, a road surface gradient sensor
The vehicle system according to claim 1, wherein the predetermined time for performing the start determination of the internal combustion engine is shortened as the road surface gradient increases.

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