JP2008049931A - Hybrid car - Google Patents

Abstract

Regenerative braking is controlled by the driver's intention.
A shift lever has a position indicating that regenerative braking is strengthened. Therefore, when the position is selected by the shift lever, the control circuit 34 controls the inverters INV1 and INV2 to control the strength of the regenerative braking.
[Selection] Figure 1

Description

  The present invention relates to a hybrid vehicle equipped with a drive motor and an engine and using regenerative braking of the drive motor for deceleration equivalent to engine braking.

  Conventionally, a hybrid vehicle equipped with both a motor and an engine is known, and has been widely spread as an environment-friendly vehicle with good fuel efficiency.

  In this hybrid vehicle, the motor is mainly used at the time of start or at low speed, and the vehicle is driven by using an engine at the time of relatively high speed. Further, when the state of charge of the battery is lowered, the engine is driven and the motor functions as a generator to charge the battery.

  Furthermore, in a hybrid vehicle, when the accelerator is released or the brake pedal is operated, regenerative braking is used as a deceleration force equivalent to engine braking. That is, the vehicle is decelerated by causing the driving motor to act as a generator, and the generated power is used for charging the battery to recover energy.

  Here, the braking force corresponding to the engine brake varies depending on the gear position. Therefore, Patent Documents 1 and 2 show that the regenerative braking force is switched according to the shift position. Further, there is a case where it is desired to travel only by a motor, and Patent Document 1 discloses that a special switch is provided to prohibit engine driving and travel only by a motor.

Japanese Patent Laid-Open No. 5-122805 JP-A-9-37407 JP 2003-235108 A

  In Patent Documents 1 and 2, the regenerative braking force is controlled according to the shift position, but in any case, only the regenerative braking force determined to be optimal in the normal travel mode is generated. Therefore, the regenerative braking force cannot be arbitrarily controlled by the driver's intention.

  The present invention has a shift lever for determining an operation mode including forward and reverse in a hybrid vehicle equipped with a drive motor and an engine and using regenerative braking of the drive motor for deceleration equivalent to engine braking. The shift lever has a forced regenerative brake setting position, and when the shift lever is in a position other than the forced regenerative brake setting position, generates a normal regenerative braking force determined according to the vehicle speed and acceleration / deceleration command at that time. When the shift lever is set to the forced regenerative brake setting position, an arbitrary regenerative braking force is generated.

  The forced regenerative brake setting position has at least two positions, the maximum position and the other position. When the shift lever is set to the maximum position, the maximum regenerative braking force is generated according to the traveling state at that time. Is preferred.

  Further, it is preferable that the shift lever further has a weak regenerative brake position, and when the shift lever is set to the weak regenerative brake position, the regenerative braking force is forcibly weakened.

  The shift lever further has a forced motor drive position. When the shift lever is set to the forced motor drive position, it is preferable that the engine is prohibited from being driven and only the motor is driven to travel. .

  According to the present invention, regenerative braking can be forcibly applied by the shift lever position. Therefore, regenerative braking can be forcibly applied by a simple operation at any time according to the preference of the driver. In addition, by making settings such as regenerative braking and prohibiting engine driving with the shift lever, a variety of travel control can be performed according to the driver's needs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a drive system of a hybrid vehicle according to the embodiment. The planetary gear 10 includes a ring gear 12, a carrier 14, and a sun gear 16. The ring gear 12 is connected to the rotation shaft of the second motor generator MG2, the carrier 14 is connected to the rotation shaft of the engine E / G, and the sun gear 16 is connected to the rotation shaft of the first motor generator MG1. Furthermore, the drive shaft 20 is connected to the ring gear 12 through, for example, a chain, and the rotation of the ring gear 12 is transmitted. A wheel 52 is connected to the drive shaft 20 via a power transmission unit 50, and rotation of the ring gear 12 is transmitted to the wheel 52.

  Here, the engine ECU 30 is connected to the engine E / G, and the engine ECU 30 controls the fuel supply to the engine E / G to control the output of the engine E / G. Further, the second inverter INV2 is connected to the second motor generator MG2, and the DC power from the battery 32 is converted into a predetermined three-phase AC current and supplied to the second motor generator MG2. Thereby, the ring gear 12 can be rotationally driven by the second motor generator MG2. Depending on the control of the inverter INV2, the second motor generator MG2 can be operated as a generator to perform regenerative braking. Further, a first inverter INV1 is connected to the first motor generator MG1, and the power generated by the first motor generator MG1 is converted into DC power and supplied to the battery 32. Therefore, the battery 32 can be charged with the power generated by the first motor generator MG1.

  The operation of the engine ECU 30 and the first and second inverters INV1 and INV2 is controlled by the control circuit 34, whereby the drive control of the engine E / G and the first and second motor generators MG1 and MG2 according to the operation state of the vehicle. Is done.

  For example, when traveling at a constant speed, the vehicle travels mainly by the output of the engine E / G. Therefore, as shown in FIG. 2, the rotational speed of the first motor generator MG1 is kept low, and power generation is not performed much.

  Further, a shift lever 54 is provided adjacent to the driver seat, and the power transmission unit 50 is operated by operating the shift lever 54. For example, when the shift lever 54 is in the parking position and the neutral position, the power transmission unit 50 disconnects the drive shaft 20 and cuts transmission of the driving force to the wheels 52. If the shift lever 54 is in the drive position, the power transmission unit 50 transmits the driving force of the drive shaft 20 to the wheel 52 as a forward drive force, and if the shift lever 54 is in the rear position, the power transmission unit 50 is connected to the drive shaft 20. The driving force is transmitted to the wheel 52 as a reverse driving force. The power transmission unit 50 may include a gear ratio changing unit. Alternatively, the power transmission unit 50 may be a simple clutch, and the reverse may be performed by reversing the first motor generator MG1.

  Information about the shift position of the shift lever 54 is supplied to the control circuit 34. The control circuit 34 controls the inverters INV1 and INV2 according to the position of the shift lever 54, and controls the driving of the motor generators MG1 and MG2. To do.

  Although FIG. 1 shows a configuration in which two motor generators are received, one motor generator may be used.

  FIG. 2 shows the configuration of the shift lever 54. In this way, the main row has normal P (parking), R (rear: reverse), N (neutral). In addition to D (drive: forward), there is M (forced motor drive). Furthermore, it has a sub row adjacent to the main row, and the strength of regenerative braking is adjusted by this sub row. That is, the regenerative braking is maximized when set at the lowest MAX position in the sub-row, and the regenerative braking is set to almost zero when set at the uppermost MIN position. Further, at the intermediate position (DS position) of the sub-row that has moved sideways as it is from the drive position, regenerative braking is normal, and by sliding in the direction of the MAX position, regenerative braking is gradually performed according to that position. The regenerative braking is gradually weakened according to the position by sliding in the direction of the MIN position. Further, before reaching the MAX position and the MIN position, a stage for movement in which the resistance to the slide becomes large is provided, and when setting the MAX position and the MIN position, the driver's clear intention is required. . Note that it is also preferable that the steps can be exceeded only by button operation.

  Here, the D (drive) position is a normal travel mode, and the control circuit 34 calculates the target drive force of the drive shaft 20 from the accelerator depression amount, the brake depression amount, the current vehicle speed, and the like, and the motor generators MG1, MG2 And adjust the engine E / G output. This control is performed in a normal hybrid vehicle. Further, regenerative braking is performed by the motor generators MG1 and MG2 depending on the situation. Further, an EV travel button 56 is also provided. When the EV travel button is on, the output of the engine E / G is basically not used for travel drive at the D position, and travel is performed by the output of the motor generator MG1. . However, in this case, when the driver greatly depresses the accelerator, the engine assist is also performed by the output of the engine E / G.

  On the other hand, in the M position, the motor is forcibly driven and the engine assist such as the EV travel button is not performed.

  At the MAX position in the sub-row, the control circuit 34 performs maximum regenerative braking in the traveling state at that time. This control is different from the deceleration based on the normal brake operation or the like, and simply regenerative braking is maximized. In other words, in inverters INV1 and INV2, the regenerative braking force is maximized by adjusting the switch timing of the switching elements and maximizing the function as the generator of motor generators MG1 and MG2.

  At the MIN position in the sub row, the control circuit 34 prohibits regenerative braking regardless of the traveling state at that time. As a result, coasting can be performed according to the driver's intention. Moreover, unnecessary regenerative braking can be prevented by selecting this MIN position when climbing. When the brake is depressed, mechanical braking or the like is performed as usual.

  Furthermore, by adjusting the shift position in the middle of the sub-row, it is possible to generate the driver's desired regenerative braking force, so that the driver can control the deceleration of the vehicle by operating the shift lever.

By providing such a shift lever of this embodiment, the following merits are obtained.
(I) The driver can adjust the degree of acceleration / deceleration at his / her will, and the variety of driving control of the driver is widened, so that a driver's satisfaction can be obtained.
(Ii) Since driving by the engine is prohibited at the M position, it is possible to reliably meet the driver's request when it is desired to move the vehicle using only the motor. In particular, unlike the EV button, the engine is not started by automatic control when the accelerator is depressed too much.
(Iii) In the sub-row, the driver can freely control the regenerative braking force, so a wide range of driving control according to the driver's preference, such as when you want to charge the battery, when you want to stop only with regenerative braking, or when you want to run inertially Can be done.
(Iv) By increasing the regenerative braking, it becomes possible to drive with higher fuel consumption depending on the driver.

It is a figure which shows the structure of embodiment. It is a figure which shows the structure of a shift lever.

Explanation of symbols

  10 planetary gear, 12 ring gear, 14 carrier, 16 sun gear, 20 drive shaft, 30 engine ECU, 32 battery, 34 control circuit, 50 power transmission unit, 52 wheels, 54 shift lever, 56 EV travel button, E / G Engine, INV1, INV2 inverter, MG1, MG2 motor generator.

Claims (4)

In a hybrid vehicle equipped with a drive motor and an engine and using regenerative braking of the drive motor for deceleration equivalent to engine braking,
While having a shift lever that determines the operation mode including forward and reverse, this shift lever has a forced regenerative brake setting position,
When the shift lever is in a position other than the forced regenerative brake setting position, a normal regenerative braking force determined according to the vehicle speed and acceleration / deceleration command at that time is generated,
A hybrid vehicle characterized by generating a set regenerative braking force regardless of the determined normal regenerative braking force when the shift lever is set to a forced regenerative braking set position. The hybrid vehicle according to claim 1,
The forced regenerative brake setting position has at least two positions of the maximum position and the other position. When the shift lever is set to the maximum position, the maximum regenerative braking force is generated according to the traveling state at that time. A featured hybrid vehicle. In the hybrid vehicle according to claim 1 or 2,
The shift lever further has a weak regeneration brake position,
A hybrid vehicle characterized by forcibly weakening the regenerative braking force when the shift lever is set to a weak regenerative braking position. The hybrid vehicle according to any one of claims 1 to 3,
The shift lever further has a forced motor drive position,
When the shift lever is set to the forced motor drive position, the hybrid vehicle is characterized in that the engine is prohibited from driving and only the motor is driven.

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