JP2010246307A - Power transmission control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To conduct an EV start without imparting a sense of incompatibility to a driver on a climbing path or a descending path in a power transmission control device for a vehicle applied to the vehicle including at least a motor as a power source. <P>SOLUTION: A power transmission control device for the vehicle includes a changeover mechanism capable of selecting the connection state of a motor output shaft to either of "an IN connection state" forming a power transmission system between a transmission input shaft and the motor output shaft, "an OUT connection state" forming the power transmission system between a transmission output shaft and the motor output shaft and "a neutral state" forming no power transmission system under both states. When the EV start is conducted on the climbing path (the descending path) under the IN or OUT connection state, an E/G driving (regenerative) torque is imparted to a driving wheel for the time (a period imparting no braking force and M/G driving torque) from the imparting completion (t2) of a brake-operation corresponding braking force to the imparting start (t3) of the M/G driving torque. 'A temporary backing before a start' on the climbing path and 'the sudden increase of a vehicle speed immediately after the starting' on the descending path are suppressed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle power transmission control device, and more particularly to a device applied to a vehicle including at least an electric motor as a power source.

  In recent years, so-called hybrid vehicles including an internal combustion engine and an electric motor (electric motor, motor generator) as power sources have been developed (see, for example, Patent Document 1). In a hybrid vehicle, an electric motor is used as a power source for generating a driving torque for driving the vehicle or as a power source for starting the internal combustion engine in cooperation with or independently of the internal combustion engine. In addition, the electric motor is used as a generator that generates regenerative torque that brakes the vehicle, or as a generator that generates electric energy supplied to and stored in the battery of the vehicle. By using the electric motor in this way, the overall energy efficiency (fuel consumption) of the entire vehicle can be improved.

JP 2000-224710 A

  By the way, in the hybrid vehicle, there are a case where a connection state (hereinafter referred to as “IN connection state”) in which a power transmission system is formed between the output shaft of the motor and the input shaft of the transmission is adopted. A connection state (hereinafter referred to as an “OUT connection state”) is adopted in which a power transmission system is formed between the output shaft of the transmission and the output shaft of the transmission (accordingly, drive wheels) without passing through the transmission. And there are cases.

  In the IN connection state, the rotational speed of the output shaft of the electric motor with respect to the vehicle speed can be changed by changing the gear position of the transmission. Therefore, by adjusting the gear position of the transmission, the rotational speed of the output shaft of the motor is maintained within a range where energy conversion efficiency (more specifically, generation efficiency of drive torque, regenerative torque, etc.) is good. There is a merit that it is easy.

  On the other hand, in the OUT connection state, there is an advantage that power transmission loss can be reduced because the power transmission system does not involve a transmission having a complicated mechanism. Further, in a transmission (especially a transmission of a type that does not include a torque converter), normally, transmission of power from the input shaft to the output shaft of the transmission is temporarily performed during a gear shift operation (a gear shift operation). It is often blocked by As a result, a rapid change in acceleration in the vehicle longitudinal direction (so-called shift shock) is likely to occur. Even during such a shift operation, in the OUT connection state, the drive torque of the motor can be continuously output to the output shaft (and hence the drive wheel) of the transmission, and there is an advantage that shift shock can be reduced. .

  In view of the above, the applicant of the present application, in Japanese Patent Application No. 2007-271556, refers to the connection state of the output shaft of the motor (hereinafter also simply referred to as “motor connection state”) as an IN connection state and an OUT connection state. A switchable switching mechanism has already been proposed. In this switching mechanism, a connection state in which a power transmission system is not formed between the output shaft of the motor and the input shaft of the transmission or between the output shaft of the motor and the output shaft of the transmission (hereinafter referred to as “non-connection state”). May also be selected.

  By the way, in the hybrid vehicle, the vehicle can start using only the drive torque of the electric motor without using the drive torque of the internal combustion engine. Hereinafter, such start is referred to as “motor start”. The motor start can be achieved in either the IN connection state or the OUT connection state. In starting the electric motor, the driving torque of the electric motor is started to be applied to the driving wheels from the start of depression of the accelerator pedal.

  Normally, when the motor starts, the driver first depresses the brake pedal and then depresses the accelerator pedal in a state where the vehicle is stopped by depressing the brake pedal, thereby starting the vehicle. Accordingly, a period during which neither the braking force (braking torque) nor the driving torque is applied between the release of the brake pedal (and hence the end of applying the braking force) and the start of depression of the accelerator pedal (and hence the start of applying the driving torque) , Called “no braking / driving torque period”).

  Due to the presence of the “no braking / driving torque period”, when the motor starts on an uphill road, a phenomenon may occur in which the vehicle temporarily moves backward before starting. Hereinafter, this phenomenon is referred to as “temporary reverse (sliding down) before starting”. In addition, when the motor starts on a downhill road, a phenomenon may occur in which the vehicle speed increases rapidly immediately after the start. Hereinafter, this phenomenon is referred to as “a sudden increase in vehicle speed immediately after starting”. Both phenomena make the driver feel uncomfortable.

  An object of the present invention is a vehicle power transmission control device that is applied to a vehicle having at least an electric motor as a power source, and is capable of starting an electric motor without causing a driver to feel uncomfortable on an uphill or downhill road. It is to provide what can be done.

  The power transmission control device for a vehicle according to the present invention drives the vehicle in the vehicle acceleration direction (forward direction) based on the detection means for detecting the operation of the acceleration operation member operated by the driver of the vehicle and the torque of the output shaft of the electric motor. A motor torque control means for applying an electric motor drive torque, which is a torque, to the drive wheels of the vehicle according to an operation of the acceleration operation member; and a braking force according to an operation of a brake operation member operated by the driver of the vehicle Braking force control means for applying a braking force corresponding to a braking operation to the wheels of the vehicle, and determination means for determining whether or not the road surface on which the vehicle is stopped is an uphill road.

  Here, the determination unit determines, for example, “uphill road” when the slope of the uphill road is equal to or greater than a predetermined value. This predetermined value is, for example, a value that is equal to or greater than the upper limit of the range in which the vehicle does not reverse during the “no braking / driving torque period”.

  The power transmission control device according to the present invention is characterized in that the motor torque control means determines that the road surface is an uphill road, and the vehicle is stopped by the braking force corresponding to the braking operation. The braking force corresponding to the braking operation reaches zero from the time before the time when the braking force corresponding to the braking operation reaches zero. After that, the motor drive torque is applied to the drive wheels until the time after the start of the operation of the acceleration operation member.

  Here, the “decreasing tendency of the braking force corresponding to braking operation toward zero” means that, for example, when the braking force corresponding to braking operation passes while decreasing a predetermined value (a minute value), the decreasing speed of the braking force corresponding to braking operation is It can be detected in the case of a predetermined value or more.

  According to the above configuration, the motor driving torque (= the torque in the vehicle acceleration direction) is continuously applied to the driving wheels over the “no braking / driving torque period”. Therefore, the occurrence of “temporary reverse before starting” can be suppressed by appropriately adjusting the magnitude of the motor driving torque. Therefore, the motor start can be executed on the uphill road without causing the driver to feel uncomfortable.

  In this case, the electric motor torque control means is configured to adjust the electric motor driving torque applied to the driving wheel to a larger value as the gradient of the uphill road or the value correlated with the uphill road is larger. It is preferred that Here, the value correlated with the slope of the uphill road is, for example, acceleration in the longitudinal direction of the vehicle body acting on the stopped vehicle.

  The greater the slope of the uphill road, the greater the magnitude of the component in the vehicle reverse direction in the gravity acting on the vehicle. Therefore, according to the above configuration, the magnitude of the motor driving torque can be adjusted to an appropriate magnitude necessary for suppressing “temporary reverse before starting” regardless of the gradient of the uphill road.

  Further, in the power transmission control device, the braking force control unit is configured to be able to apply a braking force larger than the braking force corresponding to the braking operation to the wheel, and the braking force control unit includes the braking operation From the time before the time when the corresponding braking force reaches zero to the time after the time when the braking operation corresponding braking force reaches zero and after the time when the operation of the acceleration operation member is started, A braking force greater than a braking force corresponding to a braking operation may be applied to the wheel.

  According to this, the braking force is continuously applied in addition to the motor driving torque over the “no braking / driving torque period”. Therefore, the occurrence of “temporary reverse before starting” can be more reliably suppressed than when only the motor driving torque is applied.

  Next, the motor torque control means applies not only the motor drive torque but also a motor regeneration torque that is a regeneration torque in the vehicle deceleration direction (reverse direction) based on the torque of the output shaft of the motor to the drive wheels of the vehicle. Consider a case where the determination unit is configured to determine whether or not the road surface on which the vehicle is stopped is a downhill road. Here, the determination unit determines, for example, “downhill road” when the gradient of the downhill road is a predetermined value or more. This predetermined value is, for example, a value equal to or higher than the upper limit value in a range in which the vehicle speed after the start does not increase rapidly in the “no braking / driving torque period”.

  In this case, the motor torque control means corresponds to the braking operation when the road surface is determined to be a downhill road and the vehicle is stopped by the braking force corresponding to the braking operation. When a decreasing tendency of the braking force toward zero is detected, the acceleration operation is performed after the braking operation-corresponding braking force reaches zero from the time before the braking operation-corresponding braking force reaches zero. The electric motor regeneration torque may be applied to the driving wheel until a time point after the time point when the operation of the member is started.

  According to the above configuration, the motor regeneration torque (= the torque in the vehicle deceleration direction) is continuously applied to the drive wheels over the “no braking / driving torque period”. Therefore, by appropriately adjusting the magnitude of the motor regenerative torque, the occurrence of “sudden increase in vehicle speed immediately after starting” can be suppressed. More specifically, the transition of the increase in vehicle speed immediately after starting can be adjusted appropriately. Therefore, the motor can be started on the downhill road without causing the driver to feel uncomfortable.

  In this case, the motor torque control means is configured to adjust the motor regeneration torque applied to the drive wheels to a larger value as the slope of the downhill road or the value correlated with the slope of the downhill road is larger. It is preferred that Here, the value correlated with the slope of the downhill road is, for example, acceleration in the longitudinal direction of the vehicle body acting on the stopped vehicle.

  The greater the slope of the downhill road, the greater the magnitude of the component in the vehicle forward direction in gravity acting on the vehicle. Therefore, according to the above configuration, regardless of the slope of the downhill road, the magnitude of the motor regeneration torque can be adjusted to an appropriate magnitude necessary for suppressing the “rapid increase in vehicle speed immediately after starting”. In other words, regardless of the slope of the downhill road, the transition of the increase in the vehicle speed immediately after starting can be adjusted appropriately.

  In this case, the electric motor torque control means fills a battery for supplying electric energy to the electric motor using electric power generated by the electric motor based on the electric motor regeneration torque applied to the driving wheel. It is suitable to be configured. According to this, compared with the case where the battery is not charged, the overall energy efficiency (fuel consumption) of the entire vehicle can be improved.

  As described above, the power transmission control device according to the present invention can be applied to a vehicle including an internal combustion engine in addition to the electric motor as a power source. The power transmission control device includes an input shaft that forms a power transmission system with the output shaft of the internal combustion engine, and an output shaft that forms a power transmission system with the drive wheels of the vehicle. A transmission capable of adjusting a transmission reduction gear ratio, which is a ratio of a rotation speed of the input shaft to a rotation speed of the output shaft, and a connection state of the output shaft of the motor, the output shaft of the motor and the transmission IN connection state in which a power transmission system is formed with the input shaft of the motor, and OUT where a power transmission system is formed between the output shaft of the motor and the output shaft of the transmission without passing through the transmission Of the connection state and a non-connection state in which no power transmission system is formed between the output shaft of the motor and the input shaft of the transmission or between the output shaft of the motor and the output shaft of the transmission. Switching machine that can switch to at least two states And, it can be provided with.

  In this case, the electric motor torque control means is configured to apply the electric motor driving torque or the electric motor regenerative torque to the driving wheels in a state where the IN connection state or the OUT connection state is selected by the switching mechanism. .

  Even if the transmission is a multi-stage transmission that can set a plurality of different reduction ratios that are set in advance as the transmission reduction ratio, the transmission reduction ratio can be set continuously (steplessly). ) An adjustable continuously variable transmission may be used.

  The transmission includes a torque converter and a multi-stage transmission or a continuously variable transmission (so-called automatic transmission (AT)) in which a speed change operation is automatically executed according to the running state of the vehicle. A multi-stage transmission (so-called manual transmission (MT)) that does not include a converter may be used. In the case of MT, even if the shift operation is directly executed by the driver's operating force of the shift lever, the speed is changed by the driving force of the actuator based on the signal indicating the position of the shift lever operated by the driver. Even if the operation is performed, the speed change operation can be automatically performed by the driving force of the actuator according to the traveling state of the vehicle regardless of the shift lever operation by the driver (so-called automated manual). -Transmission).

1 is a schematic configuration diagram of a vehicle equipped with a vehicle power transmission control device according to an embodiment of the present invention. It is the figure which showed 3 states which can be switched in the switching mechanism shown in FIG. It is the time chart which showed an example of the operation | movement in case the apparatus shown in FIG. 1 is applied and EV start is made | formed on a flat road (horizontal road). It is the time chart which showed an example of the operation | movement in case the apparatus shown in FIG. 1 is applied and EV start is made on an uphill road. It is the time chart which showed another example of the operation | movement in case the apparatus shown in FIG. 1 is applied and EV start is made on an uphill road. It is the time chart which showed an example of the operation | movement in case the apparatus shown in FIG. 1 is applied and EV start is made on a downhill road.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a vehicle power transmission control device according to the present invention will be described with reference to the drawings.

(Constitution)
FIG. 1 shows a schematic configuration of a vehicle equipped with a power transmission control device (hereinafter referred to as “the present device”) according to an embodiment of the present invention. This vehicle is applied to a vehicle that includes a so-called automated manual transmission that uses a multi-stage transmission that includes an internal combustion engine and a motor generator as power sources and does not include a torque converter.

  The vehicle includes an engine (E / G) 10, a transmission (T / M) 20, a clutch (C / T) 30, a motor generator (M / G) 40, a switching mechanism 50, and a braking force control. A device 60 is provided. E / G10 is one of well-known internal combustion engines, for example, a gasoline engine that uses gasoline as fuel and a diesel engine that uses light oil as fuel. The output shaft A1 of E / G10 is connected to the input shaft A2 of T / M20 via C / T30.

  The T / M 20 is one of well-known multi-stage transmissions that do not include a torque converter having a plurality of (for example, five) forward gears, one reverse gear, and a neutral gear. Hereinafter, the forward gear and the reverse gear are referred to as “travel gear”. In the traveling gear stage, a power transmission system is formed between the input / output shafts A2 and A3 of the T / M 20. In the neutral stage, a power transmission system is not formed between the input / output shafts A2 and A3 of the T / M 20. In the travel gear stage, the T / M 20 can arbitrarily set a transmission reduction ratio Gtm, which is a ratio of the rotational speed of the input shaft A2 to the rotational speed of the output shaft A3, in any of a plurality of stages. In the T / M 20, the shift speed is switched only by controlling the T / M actuator 21.

  The C / T 30 has one of well-known configurations, and is a shut-off state in which no power is transmitted between the output shaft A1 of the E / G 10 and the input shaft A2 of the T / M 20, and a joined state in which power is transmitted. Can be adjusted. Hereinafter, for convenience of explanation, a state in which the rotations of the input shaft A2 and the output shaft A3 of the T / M 20 coincide with each other in the joined state is referred to as a “completely joined state”, and a state in which the rotation does not coincide with each other Call it. In this vehicle, a clutch pedal is not provided. The state of C / T 30 is controlled by adjusting the clutch stroke by C / T actuator 31.

  The M / G 40 has one of known configurations (for example, an AC synchronous motor), and for example, a rotor (not shown) rotates integrally with the output shaft A4. The M / G 40 functions as both a power source and a generator.

  The switching mechanism 50 is a mechanism that switches the connection state of the output shaft A4 of the M / G 40. The switching mechanism 50 includes a connecting piece 51 that rotates integrally with the output shaft A4 of the M / G 40, a connecting piece 52 that rotates integrally with the gear g1, a connecting piece 53 that rotates integrally with the gear g3, a sleeve 54, and a switching actuator 55. With. The gear g1 is always in mesh with the gear g2 that rotates integrally with the input shaft A2 of the T / M 20, and the gear g3 is always meshed with the gear g4 that rotates integrally with the output shaft A3 of the T / M 20.

  The sleeve 54 is disposed so as to be coaxially movable in the axial direction of the output shaft A4 of the M / G 40, and its position in the axial direction is controlled by the switching actuator 55. The sleeve 54 can be splined to the connecting pieces 51, 52, 53.

  When the sleeve 54 is controlled to the IN connection position shown in FIG. 2A, the sleeve 54 is spline-fitted with the connecting pieces 51 and 52. Thereby, a power transmission system is formed between the input shaft A2 of the T / M 20 and the output shaft A4 of the M / G 40 via the gears g1 and g2. This state is called an “IN connection state”.

  In the IN connection state, the ratio of the rotational speed of the output shaft A4 of the M / G 40 to the rotational speed of the input shaft A2 of the T / M 20 is referred to as “first reduction ratio G1,” and the first reduction ratio G1 and the transmission reduction ratio Gtm. (G1 · Gtm) is referred to as “IN connection reduction ratio Gin”. In this example, since G1 = (number of teeth of g2) / (number of teeth of g1), Gin = (number of teeth of g2) / (number of teeth of g1) · Gtm. That is, Gin changes according to the change of the gear position of T / M20.

  When the sleeve 54 is controlled to the OUT connection position shown in FIG. 2B, the sleeve 54 is spline-fitted with the connecting pieces 51 and 53. Accordingly, a power transmission system is formed between the output shaft A3 of the T / M 20 and the output shaft A4 of the M / G 40 via the gears g3 and g4 without using the T / M 20. This state is called “OUT connection state”.

  In the OUT connection state, the ratio of the rotation speed of the output shaft A4 of the M / G 40 to the rotation speed of the output shaft A3 of the T / M 20 is referred to as “OUT connection reduction ratio Gout”. In this example, Gout is constant at (number of teeth of g4) / (number of teeth of g3). That is, Gout does not change according to the change in the gear position of T / M20.

  Further, when the sleeve 54 is controlled to the non-connection position shown in FIG. 2C, the sleeve 54 is spline-fitted only with the connecting piece 51. Thereby, a power transmission system is not formed between the output shaft A3 of the T / M 20 and the output shaft A4 of the M / G 40, or between the input shaft A2 of the T / M 20 and the output shaft A4 of the M / G 40. This state is called “neutral state”.

  As described above, the switching mechanism 50 controls the switching actuator 55 (thereby controlling the position of the sleeve 54) to thereby connect the output shaft A4 of the M / G 40 (hereinafter also referred to as “M / G connection state”). .) Can be selectively switched to any one of “IN connection state”, “OUT connection state”, and “neutral state”.

  The output shaft A3 of the T / M 20 is connected to an operating mechanism D / F, and the operating mechanism D / F is connected to a pair of left and right drive wheels. Note that a so-called final reduction mechanism may be interposed between the output shaft A3 of the T / M 20 and the operation mechanism D / F.

  The braking force control device 60 has a known configuration including a plurality of solenoid valves, a hydraulic pump, an electric motor, and the like. At the time of non-control, the braking force control device 60 supplies the braking pressure according to the operation of the brake pedal BP by the driver to the wheel cylinders of each wheel, and the braking force ( Braking torque). Hereinafter, the braking force corresponding to the operation of the BP is also referred to as “braking force corresponding to the brake operation”.

  In addition, the braking force control device 60 can control the braking pressure in the wheel cylinder for each wheel and adjust the braking force for each wheel regardless of the operation of the brake pedal BP (even when the operation is not performed). It has become. That is, a braking force larger than the braking force corresponding to the brake operation can be applied. The adjustment of the braking force is not limited to the braking pressure, but can be performed using an electric brake device.

  In addition, the present device includes a wheel speed sensor 71 that detects the wheel speed of the drive wheel, an accelerator opening sensor 72 that detects the operation amount (accelerator opening) of the accelerator pedal AP, and a shift that detects the position of the shift lever SF. A position sensor 73 and a brake sensor 74 for detecting whether or not the brake pedal BP is operated are provided.

  Furthermore, this apparatus includes an electronic control unit ECU80. The ECU 80 controls the actuators 21, 31, and 55 based on information from the sensors 71 to 74 and other sensors described above, so that the T / M 20 gear stage, the C / T 30 state, And the state of the switching mechanism 50 is controlled. In addition, the ECU 70 controls the outputs (drive torque and regenerative torque) of the E / G 10 and M / G 40 and the braking force of each wheel.

  The gear position of T / M 20 is a required torque Tr (based on the driving wheel) calculated based on the vehicle speed V obtained from the wheel speed sensor 71 and the amount of operation of the accelerator pedal AP by the driver obtained from the accelerator opening sensor 72. Torque) and the position of the shift lever SF obtained from the shift position sensor 73. When the position of the shift lever SF is at a position corresponding to the “manual mode”, the gear position of the T / M 20 is set in principle to the gear position selected by the driver by operating the shift lever SF. On the other hand, when the shift lever SF is in a position corresponding to the “automatic mode”, the shift lever SF is operated based on the combination of the vehicle speed V and the required torque Tr, etc. Not automatically controlled. Hereinafter, the operation when the gear position of the T / M 20 is changed is referred to as “shift operation”. The start of the shift operation corresponds to the start of the movement of the member that moves in relation to the change of the gear position, and the end of the shift operation corresponds to the end of the movement of the member.

  The C / T 30 is normally maintained in a joined state (particularly, a completely joined state). When the shift lever SF is in the “neutral” position during the shifting operation of the T / M 20, when the EV starts, which will be described later, It is maintained in the shut off state Further, C / T 30 is a maximum value of torque that can be transmitted (hereinafter referred to as “clutch torque Tc”) according to the clutch stroke adjusted by the C / T actuator 31 in the engaged state (particularly in the semi-joined state). Can be adjusted).

  The clutch torque Tc can be adjusted more precisely than the torque of the output shaft A1 of the E / G 10 itself. Therefore, by controlling the clutch torque Tc while maintaining the drive torque of the output shaft A1 of the E / G10 larger than the clutch torque Tc, the input shaft of the T / M20 based on the torque of the output shaft A1 of the E / G10 The torque transmitted to A2 can be finely adjusted to coincide with the clutch torque Tc.

  The M / G 40 is used as a power source for generating a driving torque for driving the vehicle or as a power source for starting the E / G 10 in cooperation with or independently of the E / G 10. The M / G 40 is also used as a generator that generates regenerative torque that brakes the vehicle, or as a generator that generates electrical energy supplied and stored in a battery (not shown) of the vehicle.

  Hereinafter, the torque of the output shaft A1 of the E / G 10 is referred to as “E / G torque”, and the torque of the output shaft A4 of the M / G 40 is referred to as “M / G torque”. The rotational speed of the output shaft A1 of the E / G 10 is referred to as “E / G rotational speed”, and the rotational speed of the output shaft A4 of the M / G 40 is referred to as “M / G rotational speed”. Further, the drive torque (positive in the vehicle acceleration direction) transmitted to the drive wheel based on the E / G torque is referred to as “E / G drive torque”. Further, when the M / G 40 is used as a power source for driving a vehicle, the drive torque (positive in the vehicle acceleration direction) transmitted to the drive wheel based on the M / G torque is referred to as “M / G drive torque”. The regenerative torque (positive in the vehicle deceleration direction) transmitted to the drive wheel based on the M / G torque when the M / G 40 is used as a vehicle braking generator is referred to as “M / G regenerative torque”. To do.

  The E / G drive torque is a value obtained by multiplying the E / G torque by the transmission reduction gear ratio Gtm (when C / T 30 is in the fully connected state). The M / G driving torque and the M / G regenerative torque are values obtained by multiplying the M / G torque by the IN connection reduction ratio Gin in the IN connection state, and in the OUT connection state, the M / G torque is multiplied by the OUT connection reduction ratio Gout. The value multiplied by. The M / G drive torque can be adjusted by adjusting the M / G torque, and the E / G drive torque can be adjusted by adjusting the E / G torque or the clutch torque.

  In this apparatus, the distribution of the E / G torque and the M / G torque is normally performed according to one of well-known methods so that the sum of the E / G drive torque and the M / G drive torque matches the required torque Tr. Adjusted. The distribution between the E / G torque and the M / G torque is adjusted based on the traveling state of the vehicle (for example, the vehicle speed V and the required torque Tr).

  In the switching mechanism 50, the M / G connection state is switched as the sleeve 54 moves. Hereinafter, this movement of the sleeve 54 is referred to as “switching operation”. The start of the switching operation corresponds to the start of the movement of the sleeve 54, and the end of the switching operation corresponds to the end of the movement of the sleeve 54. The M / G connection state can be switched based on, for example, a combination of the vehicle speed V and the required torque Tr.

(EV start)
In this apparatus, the vehicle can start using only the M / G driving torque without using the E / G driving torque. Here, “start” means that the vehicle shifts from a stopped state to a forward state. Hereinafter, such a start is referred to as “EV start”. In the EV start, C / T 30 is cut off and E / G 10 is stopped (the rotation of output shaft A1 is stopped). The EV start can be achieved in either the IN connection state or the OUT connection state. In the IN connection state, the gear position of T / M 20 is normally selected as “1st speed”, and in the OUT connection state, the gear position of T / M 20 is normally selected as “neutral speed”. In the EV start, from the start of depression of the accelerator pedal AP, application of M / G drive torque corresponding to the accelerator opening is started to the drive wheels.

  FIG. 3 shows an example of the operation when the vehicle starts EV on a flat road (horizontal road). In this example, before the time t1, when the brake pedal BP is depressed in the IN or OUT connection state and the vehicle is stopped, the operation for EV start is started at the time t1. It is shown. Hereinafter, the force to depress the brake pedal BP is referred to as “brake pedaling force”.

  Specifically, in this example, after time t1, the driver gradually releases the brake pedal BP, so that the brake pedal force decreases toward zero. Accordingly, after time t1, the braking force corresponding to braking operation (braking torque) decreases, and the braking force corresponding to braking operation reaches zero at time t2. Thereafter, the driver moves his / her foot from the brake pedal BP to the accelerator pedal AP, and starts to depress the accelerator pedal AP at time t3. Accordingly, after time t3, the accelerator opening increases from zero, and therefore the M / G drive torque also increases from zero. As a result, the vehicle speed increases from zero immediately after time t3. That is, the EV starts.

  As described above, when the EV is started, the braking force (braking torque) is usually M / G from the end of applying the braking force (time t2) to the start of applying the M / G driving torque (time t3). A period during which drive torque is not applied (hereinafter, referred to as “period without braking / driving torque”) may occur (time t2 to t3).

  When the EV starts on a flat road (horizontal road) as in the example illustrated in FIG. 3, the vehicle can be maintained in a stopped state over the “no braking / driving torque period”. However, when an EV start is made on an uphill road, a phenomenon may occur in which the vehicle temporarily moves backward before starting due to a component of the gravity acting on the vehicle in the vehicle backward direction. Hereinafter, this phenomenon is referred to as “temporary reverse (sliding down) before starting”. Further, when the EV is started on a downhill road, a phenomenon in which the vehicle speed rapidly increases immediately after the start can occur due to a component in the vehicle forward direction in the gravity acting on the vehicle. Hereinafter, this phenomenon is referred to as “a sudden increase in vehicle speed immediately after starting”.

  In this device, the M / G drive torque or the M / G regenerative torque is applied over the “no braking / driving torque period” to generate the “temporary reverse before starting” on the uphill road described above. In addition, the occurrence of “sudden increase in vehicle speed immediately after starting” on the downhill road is suppressed. Hereinafter, this will be described with reference to FIGS. Times t1 to t3 shown in FIGS. 4 to 6 respectively correspond to times t1 to t3 shown in FIG. The operation patterns of the driver's brake pedal BP and accelerator pedal AP shown in FIGS. 4 to 6 are exactly the same as those shown in FIG.

(EV start on the uphill road)
Hereinafter, suppression of occurrence of “temporary reverse before starting” on an uphill road will be described with reference to FIG. In this device, it is determined whether or not the road surface is an “uphill road” in a state where the brake pedal BP is depressed and the vehicle is stopped. Here, in this example, the “climbing road” refers to a road surface whose slope is equal to or greater than the upper limit value of the range in which the vehicle does not reverse during the “no braking / driving torque period”. On the “uphill road”, the vehicle can move backward in the “period without braking / driving torque”. The gradient of the road surface can be acquired by one of well-known methods based on the acceleration in the longitudinal direction of the vehicle body that acts on the stopped vehicle.

  When it is determined that the vehicle is in an “uphill road” and the decrease tendency toward zero of the braking force corresponding to the brake operation is detected in the vehicle stop state, the application of the M / G drive torque is started. In this example, the “decreasing tendency toward zero of the braking force corresponding to the brake operation” means that when the braking force corresponding to the brake operation passes while decreasing a predetermined value (small value), the rate of decrease of the braking force corresponding to the brake operation (> 0) can be detected, for example, when it is greater than or equal to a predetermined value. In the example shown in FIG. 4, the application of the M / G drive torque is started from the time immediately before time t2.

  The started M / G driving torque is increased to a value T1 (> 0), and is maintained at T1 after reaching T1. Then, the M / G drive torque is increased according to the accelerator opening from the time after time t3. As a result, the EV starts.

  Thus, the accelerator pedal operation is started after the braking force corresponding to the brake operation reaches zero (after time t2) from the time point before the time when the braking force corresponding to the brake operation reaches zero (time t2). The M / G driving torque (see the area shown by hatching) continues to be applied to the drive wheels until the time after the time (time t3) (and therefore at least over the “no braking / driving torque period”). . As a result, the occurrence of “temporary reverse before starting” can be suppressed. Therefore, the EV start can be executed on the uphill road without causing the driver to feel uncomfortable.

  Here, the value T1 is preferably set to the smallest value within a range in which the vehicle does not reverse in the “no braking / driving torque period”. In this case, the value T1 is set to a smaller value as the slope of the uphill road is smaller. As a result, an unnecessarily large M / G drive torque is prevented from being applied in order to suppress the occurrence of “temporary reverse before starting”.

  In addition, as shown in FIG. 5, not only the M / G torque but also the braking force may be applied over at least the “no braking / driving torque period” (time t2 to t3). This braking force is larger than the braking force corresponding to the brake operation (= 0). In the example shown in FIG. 5, the braking force is kept constant at the value F <b> 1 after the time before the time when the application of the M / G drive torque is started. The value T2 at which the M / G driving torque is maintained is smaller than the value T1 shown in FIG. 4 by the applied braking force. The time when the braking force starts to be maintained at F1 may coincide with the time when the M / G driving torque starts to be applied.

  The maintenance of the braking force at F1 is continued until a time after time t3. Thereafter, the braking force is reduced from F1 to zero, and the M / G driving torque is increased according to the accelerator opening. As a result, the EV starts.

  Thus, the accelerator pedal operation is started after the braking force corresponding to the brake operation reaches zero (after time t2) from the time point before the time when the braking force corresponding to the brake operation reaches zero (time t2). Not only M / G drive torque (refer to the shaded area) but also brake operation up to the time after the time (time t3) (and therefore at least the “no braking / driving torque period”) A braking force larger than the braking force (see the area indicated by fine dots) continues to be applied to the drive wheels. Also by this, the occurrence of “temporary reverse before starting” can be suppressed.

  Here, it is preferable that the value T2 and the value F1 are also set to the smallest value within a range in which the vehicle does not reverse during the “no braking / driving torque period”. In this case, the values T2 and F1 are set to smaller values as the slope of the uphill road is smaller. As a result, it is possible to suppress application of an unnecessarily large M / G driving torque and braking force in order to suppress the occurrence of “temporary reverse before starting”.

(EV start on downhill road)
Next, suppression of occurrence of “a sudden increase in vehicle speed immediately after starting” on a downhill road will be described with reference to FIG. In this device, it is determined whether or not the road surface is a “downhill road” in a state where the brake pedal BP is depressed and the vehicle is stopped. Here, the “downhill road” in this example refers to a road surface whose gradient (> 0) is equal to or higher than the upper limit value in a range in which the vehicle speed after the start does not increase rapidly in the “period without braking / driving torque”. On the “downhill road”, the vehicle speed after the start can rapidly increase in the “period without braking / driving torque”.

  When it is determined that the vehicle is in a “downhill road” and the decrease tendency toward zero of the braking force corresponding to the brake operation is detected in the vehicle stop state, the application of the M / G regenerative torque is started. In FIG. 6, the M / G regenerative torque is shown as a negative value. The “decreasing tendency of the braking force corresponding to the brake operation toward zero” is detected in the same manner as in the examples shown in FIGS. In the example shown in FIG. 6, the application of the M / G regenerative torque is started from the time immediately before time t2. Further, in the example shown in FIG. 6, due to the component in the vehicle reverse direction in the gravity acting on the vehicle at the time immediately before time t <b> 2 (that is, in the vicinity of the time when the application of the M / G regenerative torque is started). The vehicle is starting.

  The applied M / G regenerative torque is increased until the vehicle speed reaches a predetermined value (small value) V1 or until the magnitude of the M / G regenerative torque reaches a predetermined value, and then is maintained constant. The In the example shown in FIG. 6, the magnitude of the M / G regenerative torque is kept constant at a value (−T3). During this time, the braking force is not applied in the example shown in FIG. 6, but a braking force (that is, a braking force larger than the braking force corresponding to the brake operation) may be applied. The magnitude of this braking force is greater than the magnitude of the braking force corresponding to the brake operation applied by the brake pedal operation in order to suppress the occurrence of “a sudden increase in vehicle speed immediately after starting” when the M / G regenerative torque is not applied. small.

  Then, after time t3, the magnitude of the M / G regenerative torque is reduced to zero. As a result, the vehicle speed maintained at the predetermined value (minute value) V1 gradually increases (slowly). After the magnitude of the M / G regenerative torque reaches zero, the M / G drive torque is increased according to the accelerator opening instead of the M / G regenerative torque. As a result, the acceleration of the vehicle is continued. It should be noted that the start point of the decrease in the magnitude of the M / G regenerative torque may be a time point after time t3.

  Thus, the accelerator pedal operation is started after the braking force corresponding to the brake operation reaches zero (after time t2) from the time point before the time when the braking force corresponding to the brake operation reaches zero (time t2). M / G regenerative torque (refer to the area shown by hatching) continues to be applied to the drive wheels until the time after the time (time t3) (and therefore at least over the “no braking / driving torque period”). . As a result, the occurrence of “a sudden increase in vehicle speed immediately after starting” can be suppressed. Therefore, the EV start (precisely, the start by the action of gravity) can be executed without causing the driver to feel uncomfortable on the downhill road.

  Here, the value (−T3) (> 0) can be set to a value corresponding to a state in which the vehicle speed is maintained at the predetermined value V1, as described above. In this case, the value (−T3) is set to a smaller value as the slope (> 0) of the downhill road is smaller. As a result, regardless of the slope of the downhill road, in order to suppress the occurrence of “sudden increase in vehicle speed immediately after starting”, by extension, M having an appropriate magnitude required for maintaining the vehicle speed constant at the predetermined value V1. / G regenerative torque can be applied.

  When the vehicle does not start (due to the action of gravity) or the vehicle speed does not reach the predetermined value V1 while the M / G regenerative torque is applied, the magnitude of the M / G regenerative torque is reduced. It is preferable. The predetermined value V1 may be set to a larger value as the slope (> 0) of the downhill road is larger. Thereby, the start with less discomfort according to the gradient of the downhill road can be made.

  In addition, while the M / G regenerative torque is applied, a battery (not shown) that supplies electric energy to the M / G 40 using electric power generated by the M / G 40 based on the M / G regenerative torque. May be filled. Thereby, the total energy efficiency (fuel consumption) as the whole vehicle can be improved.

  The present invention is not limited to the above embodiment, and various modifications can be employed within the scope of the present invention. For example, in the above embodiment, a vehicle including E / G10 and M / G40 is used as a power source, but a vehicle including only M / G40 as a power source may be used. Moreover, in the said embodiment, although T / M20 is provided, T / M20 may be abbreviate | omitted.

  In the above embodiment, the switching mechanism 50 that can be switched to any of the IN connection state, the OUT connection state, and the neutral state is used. However, as the switching mechanism 50, the IN connection state and the neutral state are used. A switchable switch may be used. In this case, EV start is performed in the IN connection state. Similarly, a switching mechanism 50 that can be switched only to the OUT connection state and the neutral state may be used. In this case, EV start is performed in the OUT connection state. Further, the switching mechanism 50 itself may be omitted, and the IN connection state or the OUT connection state may always be achieved.

  In the above-described embodiment, a so-called automated manual transmission using a multi-stage transmission that does not include a torque converter is used as a transmission. Accordingly, a multi-stage transmission or a continuously variable transmission (so-called automatic transmission (AT)) in which a shift operation is automatically executed may be used.

  In addition, when the EV is started, it may be determined which of the IN connection state and the OUT connection state is selected according to the road gradient. This point will be described below. The maximum value of torque transmitted to the drive wheel based on the torque of the output shaft A4 of the M / G 40 is defined as “M / G output maximum torque”.

  “Maximum M / G output torque” at the time of EV start is a value obtained by multiplying “maximum value of M / G torque at M / G rotational speed = 0” by “IN connection reduction ratio Gin” in the IN connection state. In the OUT connection state, the value is equal to a value obtained by multiplying “maximum value of M / G torque at M / G rotational speed = 0” by “OUT connection reduction ratio Gout”. Therefore, when the “IN connection reduction ratio Gin” and the “OUT connection reduction ratio Gout” at the time of EV start are different, the “M / G output maximum torque” is different between the IN connection state and the OUT connection state. In addition, a larger M / G driving torque (M / G regenerative torque) is required as the slope of the uphill road (downhill road) is larger.

  From the above, when the EV starts and the road surface gradient is greater than or equal to a predetermined value (> 0), the connection state with the larger “M / G output maximum torque” is selected from the IN or OUT connection states, and the road surface If the slope of the output is less than the predetermined value, the connection state with the smaller “M / G output maximum torque” among the IN or OUT connection states can be selected. For example, the OUT connection reduction ratio Gout is set in the vicinity of a value corresponding to “second speed” of the transmission reduction ratio Gtm, and “1st speed” is selected as the gear position in principle when the EV starts in the IN connection state. Shall be. In this case, the relationship of Gin> Gout is established when the EV starts. Therefore, the IN connection state can be selected when the road surface gradient is greater than or equal to a predetermined value (> 0), and the OUT connection state can be selected when the road surface gradient is less than the predetermined value.

  DESCRIPTION OF SYMBOLS 10 ... Engine, 20 ... Transmission, 30 ... Clutch, 40 ... Motor generator, 50 ... Switching mechanism, 60 ... Braking force control device, 71 ... Wheel speed sensor, 72 ... Accelerator opening sensor, 73 ... Shift position sensor, 74 ... Brake sensor, 70 ... ECU, AP ... Accelerator pedal, BP ... Accelerator pedal, SF ... Shift lever

Claims (7)

A vehicle power transmission control device applied to a vehicle including at least an electric motor as a power source,
Detecting means for detecting an operation of an acceleration operating member operated by a driver of the vehicle;
Electric motor torque control means for applying electric motor driving torque, which is driving torque in the vehicle acceleration direction based on torque of the output shaft of the electric motor, to the driving wheels of the vehicle according to operation of the acceleration operation member;
Braking force control means for applying a braking force corresponding to a braking operation, which is a braking force according to an operation of a braking operation member operated by a driver of the vehicle, to the wheels of the vehicle;
Determining means for determining whether the road surface on which the vehicle is stopped is an uphill road;
With
The motor torque control means is
When the road surface is determined to be an uphill road, the braking force corresponding to the braking operation tends to decrease toward zero when the vehicle is stopped by the braking force corresponding to the braking operation. When detected, after a point before the point when the braking force corresponding to the braking operation reaches zero and after the point when the braking force corresponding to the braking operation reaches zero and after the operation of the acceleration operation member is started A power transmission control device for a vehicle configured to apply the electric motor drive torque to the drive wheels up to the point of time. The power transmission control device for a vehicle according to claim 1,
The motor torque control means is
A vehicle power transmission control device configured to adjust the electric motor drive torque applied to the drive wheel to a larger value as the slope of the uphill road or a value correlated with the slope of the uphill road is larger. In the vehicle power transmission control device according to claim 1 or 2,
The braking force control means includes
A braking force larger than the braking force corresponding to the braking operation can be applied to the wheel,
The braking force control means includes
From the time before the time when the braking force corresponding to the braking operation reaches zero to the time after the time when the braking force corresponding to the braking operation reaches zero and after the time when the operation of the acceleration operation member is started. A vehicle power transmission control device configured to apply a braking force larger than the braking force corresponding to the braking operation to the wheels. A vehicle power transmission control device applied to a vehicle including at least an electric motor as a power source,
Detecting means for detecting an operation of an acceleration operating member operated by a driver of the vehicle;
A motor driving torque, which is a driving torque in a vehicle acceleration direction based on the torque of the output shaft of the motor, is applied to the driving wheels of the vehicle according to the operation of the acceleration operation member, and the vehicle is based on the torque of the output shaft of the motor Motor torque control means for applying a motor regeneration torque, which is a regeneration torque in a deceleration direction, to the drive wheels of the vehicle;
Braking force control means for applying a braking force corresponding to a braking operation, which is a braking force according to an operation of a braking operation member operated by a driver of the vehicle, to the wheels of the vehicle;
Determining means for determining whether the road surface on which the vehicle is stopped is a downhill road;
With
The motor torque control means is
When the road surface is determined to be a downhill road, the braking force corresponding to the braking operation tends to decrease toward zero when the vehicle is stopped by the braking force corresponding to the braking operation. When detected, after a point before the point when the braking force corresponding to the braking operation reaches zero and after the point when the braking force corresponding to the braking operation reaches zero and after the operation of the acceleration operation member is started A power transmission control device for a vehicle configured to apply the electric motor regeneration torque to the drive wheels until the point of time. The vehicle power transmission control device according to claim 4,
The motor torque control means is
A vehicle power transmission control device configured to adjust the electric motor regeneration torque applied to the drive wheel to a larger value as the slope of the downhill road or the value correlated with the slope of the downhill road is larger. In the vehicle power transmission control device according to claim 4 or 5,
The motor torque control means is
A power transmission control device for a vehicle configured to fill a battery that supplies electric energy to the electric motor using electric power generated by the electric motor based on the electric motor regenerative torque applied to the driving wheel. . A vehicle power transmission control device according to any one of claims 1 to 6,
Applied to a vehicle having an internal combustion engine in addition to the electric motor as a power source,
An input shaft that forms a power transmission system with the output shaft of the internal combustion engine; and an output shaft that forms a power transmission system with the drive wheels of the vehicle, the rotational speed of the output shaft being A transmission capable of adjusting a transmission reduction ratio, which is a ratio of the rotational speed of the input shaft;
The connection state of the output shaft of the motor, the input side connection state in which a power transmission system is formed between the output shaft of the motor and the input shaft of the transmission, and the output shaft of the motor and the output of the transmission An output side connection state in which a power transmission system is formed without passing through the transmission between the shaft and an output shaft of the motor and the transmission between the output shaft of the motor and the input shaft of the transmission. A switching mechanism that can be switched to at least two or more of the non-connected state in which a power transmission system is not formed between the output shaft and the output shaft;
With
The motor torque control means is
A vehicle power transmission control device configured to apply the electric motor driving torque or the electric motor regeneration torque to the driving wheels in a state where the input side connection state or the output side connection state is selected by the switching mechanism. .

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