JP2013159330A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid vehicle configured to change engine start mode in accordance with a state of a power transmission path between a driving wheel and a motor.SOLUTION: When a power transmission passage 7 is cut off between a driving wheel 10 and a motor/generator 3 during stop where an engine 2 is stopped, a hybrid vehicle 1 selects a start mode to engage an automatic clutch 11 and to start the engine 2 by power of the motor/generator 3. When not, the hybrid vehicle 1 selects a start mode to release the automatic clutch 11 and to start the engine 2 by power of a starter 5.

Description

  The present invention relates to a hybrid vehicle provided with an internal combustion engine and an electric motor as a driving power source.

  As a hybrid vehicle, when the engine 1 is automatically stopped when the vehicle starts from a stopped state, the first gear mechanism G1 is brought into a neutral state and the outer clutch 21 is connected to start the engine 1 with the electric motor 2. Known (Patent Document 1). In addition, there are Patent Documents 2 to 4 as prior art documents related to the present invention.

JP 2011-126318 A JP 2004-142636 A JP-A-11-257118 Japanese Patent Laid-Open No. 60-8440

  In recent years, hybrid vehicles have been proposed in which a manual transmission and a manual clutch are combined in a drive system including an engine and an electric motor. Since these manual transmissions and manual clutches are operated based on the driver's intention, the power transmission path is intermittently connected between the electric motor and the drive wheels according to the driver's intention. Therefore, even if it is going to restart an engine using an electric motor like the vehicle of patent document 1, the power transmission path is not necessarily divided between the electric motor and the drive wheel. For example, when the motor is driven when the engine is restarted, if the power transmission path is not divided between the motor and the drive wheels, the power of the motor is output from the drive wheels against the driver's will and the driver May give a sense of incongruity.

  Therefore, an object of the present invention is to provide a hybrid vehicle that can change the engine start mode in accordance with the state of the power transmission path between the drive wheels and the electric motor.

  The hybrid vehicle of the present invention includes an engine, drive wheels, an electric motor provided in a power transmission path that transmits the power of the engine to the drive wheels, and the power transmission path between the electric motor and the drive wheels. A manual transmission provided, an automatic clutch provided in the power transmission path between the engine and the electric motor, a manual clutch provided in the power transmission path between the electric motor and the manual transmission, Based on whether or not the power transmission path is disconnected between the drive wheel and the electric motor when the engine is stopped and the starter for starting the engine is stopped, the automatic clutch is released. A first start mode in which the engine is started by the power of the starter, and the automatic clutch is engaged. A second engine start control means for switching a starting mode for starting the engine by the power of the motor, but with a (claim 1).

  According to this hybrid vehicle, a first start mode in which the automatic clutch is released and the engine is started with the power of the starter, and a second start mode in which the automatic clutch is engaged and the engine is started with the power of the electric motor. Since the power transmission path can be switched between the driving wheel and the electric motor according to whether or not the power transmission path is divided, it is possible to select a start mode suitable for the state of the power transmission path. Further, since the starter is used less frequently than when the engine is started with only the starter, the demand for the durability of the starter can be eased.

  For example, in one aspect of the hybrid vehicle of the present invention, the engine start control means may be configured such that the engine starts in the second start form when the power transmission path is divided between the drive wheel and the electric motor. May be started (Claim 2). According to this aspect, since the engine is started using the electric motor only when the power transmission path is divided between the driving wheel and the electric motor, the electric power of the electric motor is transmitted to the driving wheel against the driver's intention. Can be avoided.

  In this aspect, the power transmission path is divided between the electric motor and the drive wheel by the manual clutch while the engine start control means starts the engine in the second start mode. When the state changes from the state to the connected state, the engine may be started by switching from the second start form to the first start form (Claim 3). In this case, it is possible to avoid a situation in which the power of the motor is output to the drive wheels even when the state of the power transmission path changes from the divided state to the connected state before the start of the engine according to the second start mode is completed. .

  As described above, according to the hybrid vehicle of the present invention, the first start mode in which the automatic clutch is disengaged and the engine is started with the power of the starter, and the automatic clutch is engaged and the engine is started with the power of the electric motor. The second starting mode to be switched can be switched depending on whether or not the power transmission path is divided between the drive wheel and the electric motor, so the starting mode corresponding to the state of the power transmission path is selected. can do. Further, since the starter is used less frequently than when the engine is started with only the starter, the demand for the durability of the starter can be eased.

1 is a diagram schematically illustrating an overall configuration of a hybrid vehicle according to an embodiment of the present invention. The flowchart which showed an example of the control routine of the hybrid vehicle of FIG.

  As shown in FIG. 1, the hybrid vehicle 1 has an internal combustion engine (hereinafter referred to as an engine) 2 as a driving power source and a motor generator (hereinafter referred to as MG) corresponding to the electric motor according to the present invention. .) 3. Although the detailed description is omitted, the engine 2 is configured as a reciprocating spark ignition type internal combustion engine. A starter 5 used for starting the engine 2 is attached to the engine 2. MG3 has both a function as an electric motor and a function as a generator. When the hybrid vehicle 1 decelerates, etc., regenerative control is performed so that the MG 3 functions as a generator, and the electric power generated by the MG 3 is stored in a battery (not shown).

  The hybrid vehicle 1 has drive wheels 10, and an MG 3 is provided in a power transmission path 7 from the engine 2 to the drive wheels 10. A power transmission path 7 between the MG 3 and the drive wheels 10 is provided with a manual transmission (hereinafter referred to as MT) 8 operated by the driver, and the engine 2 and the MG 3 output via the MT 8 are connected to the power transmission path 7. The power is distributed to the left and right drive wheels 10 via the differential mechanism 9. The MT8 has six forward speeds and one reverse speed, and switching between the respective speeds is realized by operating a shift knob (not shown) by a driver and operating a gear mechanism (not shown) according to the movement of the shift knob. Is done. In addition, MT8 can be switched to the neutral state which divides the power transmission path 7 from each gear.

  An automatic clutch 11 is provided on the power transmission path 7 between the engine 2 and the MG 3, and a manual clutch 12 is provided on the power transmission path 7 between the MG 3 and MT 8. The automatic clutch 11 is configured as a well-known electromagnetic clutch that is operated by controlling power supply. The automatic clutch 11 is switched from the engaged state to the released state when electric power is supplied, and returns to the engaged state when the electric power supply is stopped. The automatic clutch 11 disconnects the power transmission path 7 in the released state and connects the power transmission path 7 in the engaged state. The manual clutch 12 is switched from the engaged state to the released state when a clutch pedal (not shown) is depressed by the driver, and is engaged when the clutch pedal is released and the clutch pedal returns to the original state. Return. Similarly to the automatic clutch 11, the manual clutch 12 also disconnects the power transmission path 7 in the released state and connects the power transmission path 7 in the engaged state.

  Each operation of the engine 2, MG3, starter 5, and automatic clutch 11 is controlled by an electronic control unit (ECU) 20 configured as a computer. The ECU 20 performs various controls such as combustion control of the engine 2 and switching control of the travel mode of the hybrid vehicle 1, but here, the control performed by the ECU 20 in relation to the present invention will be described, and description of other controls will be omitted or simplified. Turn into.

  The ECU 20 is connected to detection devices such as various sensors in order to acquire physical quantities used in various controls. As a detection apparatus related to the present invention, a crank angle sensor 21 that outputs a signal corresponding to the rotational speed (rotational speed) of the engine 2, a vehicle speed sensor 22 that outputs a signal corresponding to the vehicle speed of the hybrid vehicle 1, and an MT8 are neutral. A neutral switch 23 that outputs a signal in the case of a state, a clutch sensor 24 that detects whether the automatic clutch 11 is in a released state or an engaged state, and whether the manual clutch 12 is in a released state or an engaged state Are respectively provided, and these output signals are input to the ECU 20.

  The present embodiment is characterized in the control contents for restarting the engine 2 while the hybrid vehicle 1 is stopped. The program of the control routine shown in FIG. 2 is stored in the ECU 20 and is read out in a timely manner and repeatedly executed while the engine 2 is stopped at a predetermined interval.

  In step S <b> 1, the ECU 20 refers to the signal of the vehicle speed sensor 22 for the vehicle speed of the hybrid vehicle 1 and determines whether or not the vehicle 1 is stopped. If the vehicle is stopped, the process proceeds to step S2. If not, the subsequent process is skipped and the current routine is terminated. In step S2, the ECU 20 determines whether or not there is a request for starting the engine 2. The start request is generated when a predetermined start condition is satisfied. As this starting condition, various conditions are set such as when the driver detects an operation for preparing to start, for example, an operation to release a brake pedal (not shown), or when the remaining battery level falls below a predetermined value. Is done. If there is a request to start the engine 2, the process proceeds to step S2, and if not, the subsequent process is skipped and the current routine is terminated.

  In step S3, the ECU 20 determines whether MT8 is in a neutral state and the manual clutch 12 is in a released state. In other words, the ECU 20 determines whether or not the power transmission path 7 is divided between the drive wheel 10 and the MG 3. Whether or not it is in the neutral state is determined based on the output signal of the neutral switch 23, and whether or not the manual clutch 12 is in the released state is determined based on the output signal of the clutch sensor 25.

  If the power transmission path 7 is divided between the drive wheel 10 and the MG 3, the power of the MG 3 is not transmitted to the drive wheel 10. Therefore, the ECU 20 advances the process to step S4, sets the automatic clutch 11 to the engaged state, and starts the engine 2 with the power of MG3. This starting form corresponds to the second starting form. The specific starting procedure is the same as a known method. That is, the ECU 20 drives the MG 3 to crank the engine 2 and execute fuel injection to ignite the air-fuel mixture in the combustion chamber at a predetermined timing. Then, the ECU 20 determines whether or not the rotation speed of the engine 2 is higher than the start completion determination value capable of independent operation based on the output signal of the crank angle sensor 21, and when the rotation speed exceeds the start completion determination value. Assuming that the engine 2 has been started, the driving of the MG 3 is stopped.

  On the other hand, when the power transmission path 7 is not divided, that is, when the MT 8 is not in the neutral state or the manual clutch 12 is in the engaged state, the power of the MG 3 may be transmitted to the drive wheels 10. Therefore, the ECU 20 advances the process to step S5 to start the engine 2 with the power of the starter 5 with the automatic clutch 11 in the released state. This starting form corresponds to the first starting form. Since the specific starting procedure is the same as the above method except that the driving source for starting is different, the description is omitted. In this starting mode, the starter 5 is driven while the automatic clutch 11 is disengaged, so that the driving force of the starter 5 is not output to the drive wheels 10, so that the driver's feeling is not affected.

  In step S6, the ECU 20 determines whether MT8 is in a non-neutral state and the manual clutch 12 is in an engaged state during start-up using the MG3. That is, the ECU 20 performs the above determination after starting the execution of the second start mode and during starting before the rotation speed of the engine 2 exceeds the start completion determination value. As a result, it is determined whether the power transmission path 7 between the drive wheel 10 and the MG 3 is changed from the disconnected state to the connected state by the operation of the driver during the startup of the engine 2 using the MG 3. If there is such a change, the power of the MG 3 may be transmitted to the drive wheel 10, so the ECU 20 proceeds to step S7 to switch the automatic clutch 11 from the engaged state to the released state, and the following step In S8, the engine 2 is switched to start using the starter 5. That is, when the power transmission path 7 is changed from the divided state to the connected state during the start of the engine 2 according to the second start form, the start form is changed from the second start form to the first start form. Can be switched to. Even in such a case, it is possible to avoid a situation in which the power of the MG 3 is output to the drive wheels 10. The ECU 20 functions as engine start control means according to the present invention by repeatedly executing the control routine of FIG.

  According to this embodiment, the first start mode in which the engine 2 is started with the power of the starter 5 with the automatic clutch 11 in the disengaged state, and the second start mode with the power of the MG 3 with the automatic clutch 11 engaged. Since the start mode can be switched depending on whether or not the power transmission path 7 is divided between the drive wheel 10 and the MG 3, the start mode corresponding to the state of the power transmission path 7 is selected. be able to. Further, since the use frequency of the starter 5 is reduced as compared with the case where the engine 2 is started only by the starter 5, the demand for durability of the starter 5 can be eased. In particular, when the power transmission path 7 is changed from the disconnected state to the connected state during the start of the engine 2 in the second start form using the MG 3, the start form is changed from the second start form to the second start form. Therefore, even in such a case, the situation where the power of the MG 3 is output to the drive wheels 10 can be avoided.

  This invention is not limited to the said form, It can implement with a various form within the range of the summary of this invention. As long as it is based on whether or not the power transmission path is divided between the drive wheel and the electric motor, the condition for switching between the first start mode and the second start mode can be determined as appropriate. For example, even if the power transmission path is cut off, the engine is started in the first starting form using the starter when a specific condition such as, for example, the remaining amount of the battery is low and the drive of the motor is hindered is satisfied. You can also Even if the power transmission path is connected, for example, there are specific conditions such as when the vehicle is stopped on a downward slope or when the driver depresses the accelerator pedal and the required driving force is higher than a predetermined value. If established, the engine can be started in the second starting form using an electric motor.

  The power transmission path according to the present invention is not limited to the form extending straight from the engine toward the drive wheel as in the above-described form. For example, in the process from the engine to the drive wheel, even if it is a power transmission path where the path branches into two and merges again, the engine can be started by the motor and the power of the motor can be output to the drive wheel If so, the power transmission path according to the present invention is established.

1 Hybrid vehicle 2 Engine 3 MG (electric motor)
5 Starter 7 Power transmission path 8 MT
DESCRIPTION OF SYMBOLS 10 Drive wheel 11 Automatic clutch 12 Manual clutch 20 ECU (engine starting control means)

Claims (3)

  An engine, driving wheels, an electric motor provided in a power transmission path for transmitting the power of the engine to the driving wheels, a manual transmission provided in the power transmission path between the electric motor and the driving wheels, An automatic clutch provided in the power transmission path between the engine and the electric motor, a manual clutch provided in the power transmission path between the electric motor and the manual transmission, and for starting the engine Based on whether or not the power transmission path is disconnected between the drive wheel and the electric motor when the engine is stopped when the vehicle is stopped, the automatic clutch is released and the engine is driven by the power of the starter. A first start mode for starting the engine, and the automatic clutch in an engaged state to drive the engine with the power of the motor. Hybrid vehicle provided with an engine start control means for switching between the second start-up mode to start the down, the.   2. The hybrid vehicle according to claim 1, wherein the engine start control means starts the engine in the second start mode when the power transmission path is divided between the drive wheel and the electric motor. 3.   The engine start control means is connected from a state where the power transmission path is divided between the electric motor and the drive wheels by the manual clutch while the engine is started in the second start mode. The hybrid vehicle according to claim 2, wherein the engine is started by switching from the second starting form to the first starting form when the engine is changed to a state where the engine is changed.

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