JP3824569B2 - Hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid vehicle capable of improving worsening of fuel consumption due to inertia mass of a rotary part integrally rotating along with rotation of an engine. <P>SOLUTION: The hybrid vehicle is provided with an engine 1; an electric motor 2; a transmission 6 with a toque converter 5; and a lock up clutch 5a for the torque converter 5. If the lock up clutch 5a is in a fastening release state, operation of the electric motor 2 is controlled such that torque for driving running determined based on drive information for running including information on an accelerator operation amount is outputted. And if the lock up clutch 5a is in a fastened state, operation of the electric motor 2 is controlled so that an increase correction torque obtained by adding the torque for running drive and torque for addition determined based on information of an increase amount per a unit time of the rotation speed of the engine 1 is outputted. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention controls an engine, an electric motor that assists the engine, a transmission with a torque converter, a lock-up clutch for the torque converter, the operation of the engine and the electric motor, and the lock-up The present invention relates to a hybrid vehicle provided with control means for switching and controlling the engagement state of a clutch.
[0002]
[Prior art]
Such a hybrid vehicle charges the battery with the electric power obtained by the regenerative operation of the electric motor, and uses the electric power of the battery to power the engine to power the engine. By assisting, the fuel consumption of the engine can be reduced while obtaining a desired driving force.
[0003]
Conventionally, the arrangement configuration of the electric motor with respect to the engine in the hybrid vehicle and the control of the electric motor when assisting the engine have been configured as follows. In other words, if the electric motor is directly connected so as to rotate integrally with the engine, and if the state of charge of the battery is equal to or greater than the set amount, the driving drive torque required for the driving drive obtained based on the accelerator opening information is output. As described above, there is one configured to control the operation of the electric motor (see, for example, Patent Document 1).
[0004]
As another conventional technique, there is a configuration in which the electric motor in the hybrid vehicle is arranged with respect to the engine and the electric motor is controlled as follows when assisting the engine. In other words, the engine and the electric motor are linked and linked through a planetary gear mechanism, and the driving force required for traveling is obtained based on the driving information for driving such as the accelerator operation amount and the vehicle speed, and the engine is made fuel-efficient. In this configuration, the operation of the electric motor is controlled so as to output a traveling driving force (traveling driving torque) that is insufficient with the engine power (see, for example, Patent Document 2).
[0005]
Conventionally, when the power of the engine is shifted by a transmission with a torque converter and transmitted to the traveling device, the control means engages a lock-up clutch based on, for example, switching information on the number of shift stages of the transmission. Switching control for releasing the engagement or releasing the engagement is performed, and the switching control of the lockup clutch and the operation control for the driving torque as described above are performed separately. (For example, see Patent Document 3).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-299004 (page 2 to page 4, FIGS. 1 to 3)
[Patent Document 2]
JP 2002-152907 A (pages 5 to 6, FIG. 1 and FIG. 6)
[Patent Document 3]
JP-A-8-254266 (pages 4-6, FIGS. 1 and 5)
[0007]
[Problems to be solved by the invention]
As described above, in the related art, when assisting engine power using an electric motor, an electric motor is always output so as to output a driving torque obtained based on driving information such as an accelerator operation amount. Although the configuration is such that the operation of the motor is controlled, there is still room for improvement in the above-described conventional configuration in terms of improving the fuel consumption of the engine.
[0008]
That is, when the factors that deteriorate the fuel consumption of the engine are examined, the inertia mass in the rotating portion that rotates integrally with the rotation of the engine is one of the causes of the deterioration of the fuel consumption of the engine.
In addition, in an engine, there is a large mass in a rotating portion that rotates integrally with the rotation of the engine, such as a crank or a torque converter drive-side rotating body, and such a rotating portion is rotated by the engine. Sometimes large energy is required, and fuel consumption increases accordingly, which is a factor that deteriorates the fuel consumption of the engine, and there is room for improvement in this respect.
[0009]
The present invention has been made paying attention to such a point, and an object of the present invention is to provide a hybrid capable of improving deterioration in fuel consumption caused by an inertia mass of a rotating portion that rotates integrally with the rotation of the engine. The point is to provide a vehicle.
[0010]
[Means for Solving the Problems]
The hybrid vehicle according to claim 1 controls the operation of the engine, an electric motor that assists the engine, a transmission with a torque converter, a lock-up clutch for the torque converter, the engine and the electric motor. And control means for switching and controlling the engagement state of the lock-up clutch, and if the control means is in the engagement-released state, information on the accelerator operation amount is provided. If the operation of the electric motor is controlled so as to output the driving torque obtained based on the driving information including the driving and the lock-up clutch is in the engaged state, the driving includes information on the accelerator operation amount. Per unit time between the driving torque obtained based on the driving information and the rotational speed of the engine. To output an increment of increase correction torque obtained by adding the addition torque obtained based on the information, characterized in that it is configured to control the operation of the electric motor.
[0011]
That is, the travel drive torque obtained based on the travel drive information including information on the accelerator operation amount is added to the addition torque obtained based on the increase amount information per unit time of the engine rotation speed. The operation of the electric motor is controlled so as to output the increased correction torque obtained in this way. The addition torque is used as a torque for changing the rotation speed with respect to the inertia mass of the rotating portion that rotates integrally with the rotation of the engine such as the crank and the drive side rotating body of the torque converter. become.
In this way, by outputting the driving torque, the torque required for the vehicle to travel is output and the vehicle is driven well, and the addition torque is added and output. The driving energy of the engine for rotating the inertial mass can be reduced, and the fuel supply amount can be reduced accordingly, and the fuel consumption can be further reduced.
[0012]
By the way, when the present applicant conducted an experiment with the configuration as described above, when the control for operating the electric motor to output the increase correction torque as described above is always executed, the engine When the electric motor is operated to output a large torque obtained by adding the addition torque in addition to the traveling drive torque when the amount of increase in the rotational speed of the motor is large, the torque converter locks up. It has been found that the following problems occur when the clutch is in the released state.
[0013]
As an experiment content, for example, based on the characteristics shown in FIG. 11, the addition torque with respect to the increase amount of the engine speed per unit time is obtained, and obtained based on the driving information for driving such as the accelerator operation amount. The operation of the electric motor is controlled so as to output a value obtained by adding the addition torque to the travel driving torque. As a result, when the vehicle is started and accelerated by the accelerator operation, the accelerator operation amount is kept constant and the vehicle is running at a constant vehicle speed of about 40 km / h. For example, as shown in FIG. 15 (5), a torque that increases pulsatically with an interval of about 1 second is generated as the addition torque L1 obtained based on the pulsation torque. As a result, a slight vibration was generated in the vehicle body, resulting in a reduced ride comfort. If the lock-up clutch for the torque converter is in the engaged state, such pulsating torque is not generated, and the assist by the electric motor is properly performed and no problem occurs. In FIG. 15, (1) is the engine speed, (2) is the vehicle speed, (3) is the travel drive torque, (4) is the accelerator operation amount, and (6) is the addition torque and travel drive. The time-dependent change state of each increase correction torque obtained by adding the torque is shown. Here, since the accelerator operation amount is small and the vehicle is traveling at a low speed, the traveling drive torque is a negative value, that is, a torque for performing a regenerative operation during stable traveling.
[0014]
Therefore, if the lock-up clutch is in the engaged state, it is obtained based on information on the amount of increase per unit time of travel drive torque and engine rotation speed obtained based on the travel drive information including information on the accelerator operation amount. The electric motor is controlled so as to output an increase correction torque obtained by adding the obtained addition torque, but if the lockup clutch is in a disengaged state, the travel drive information including information on the accelerator operation amount is included. The electric motor is controlled so as to output the driving torque required based on the driving torque.
[0015]
That is, if the lock-up clutch is in the engaged state, an engine for rotating the inertial mass by outputting an increase correction torque obtained by adding the traveling drive torque and the addition torque as described above. It becomes possible to reduce the driving energy and reduce fuel consumption. At this time, since the lockup clutch is in the engaged state, no pulsating torque is generated as shown in FIG. 15, and there is no possibility that the riding comfort of the vehicle body deteriorates due to the pulsating torque.
[0016]
Further, if the lock-up clutch is in the disengaged state, the electric motor is controlled so as to output the travel drive torque obtained based on the travel drive information including information on the accelerator operation amount. By outputting the driving torque, the torque required for driving the vehicle is output and the driving of the vehicle is performed satisfactorily. Also, only the driving torque is added without adding the addition torque as described above. However, although the effect of suppressing deterioration of fuel consumption due to inertial mass cannot be exhibited, there is no possibility of generating pulsating torque as shown in FIG.
[0017]
Therefore, it is possible to improve the deterioration of fuel consumption due to the inertia mass of the rotating part that rotates integrally with the rotation of the engine while avoiding the deterioration of the riding comfort due to the generation of the pulsating torque as described above. It has become possible to provide a hybrid vehicle.
[0018]
A hybrid vehicle according to a second aspect is the hybrid vehicle according to the first aspect, wherein the control means obtains the torque for addition as a value that increases as the amount of increase in the rotational speed of the engine per unit time increases. It is characterized by being.
[0019]
That is, as the amount of increase in the rotational speed of the engine per unit time is larger, the driving energy for rotating the inertial mass of the rotating part that rotates integrally with the rotation of the engine also increases. By obtaining the addition torque as a value that increases as the increase amount increases and outputting the addition torque by the electric motor, the torque of the electric motor increases corresponding to the magnitude of the drive energy. It is possible to more efficiently suppress the deterioration of fuel consumption due to the fuel cell.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a hybrid vehicle according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the hybrid vehicle is directly connected so that the travel drive engine 1 and the travel drive electric motor 2 rotate integrally. In other words, the electric motor 2 for driving driving is provided in a state directly connected to the output shaft 1a of the engine 1 for driving driving, and driving is performed by driving the left and right wheels 3 as a driving device with these powers. A drive unit KU as means is configured. The electric motor 2 is connected to the output shaft 1a of the engine 1 so that the rotor 2a rotates integrally with the same axis, and the stator 2b surrounding the outer periphery of the rotor 2a is fixed to a vehicle body support portion (not shown) in a fixed position. It becomes the structure supported.
[0021]
The electric motor 2 is configured to start the engine 1 by applying a driving force to the output shaft 1a in a state where the operation of the engine 1 is stopped. The output shaft 1a can be switched between a power running state in which a driving force in the same direction as the engine rotation direction is applied to assist or assist the power, and a regenerative state in which the driving force is applied from the output shaft 1a. It is configured. That is, the electric motor 2 is switched to a power running state in which torque is output in the same direction as the rotation direction with respect to the output shaft 1a that is rotationally driven by the engine 1, so that the engine 1 can output the desired driving force. The engine 1 is configured to assist the output of the engine 1 so as to achieve a low fuel consumption state. This operating state corresponds to the power running operation. Further, when the traveling speed is reduced, the electric motor 2 is in a regenerative state, and the battery 4 can be charged with the regenerative electric power obtained by generating the driving force from the output shaft 1a. It has become. This operating state corresponds to the regenerative operation.
[0022]
The power of the drive unit KU is transmitted to a transmission 6 as a transmission with a torque converter 5, and after being shifted by a gear-type automatic transmission mechanism inside the transmission 6, the left and right wheels 3 are connected via a differential mechanism 7. It has a structure that can be communicated to. The torque converter 5 includes a lock-up clutch 5a that can be switched between a fastening state in which the driving side and the driven side are fastened so as to rotate integrally and a fastening release state in which the fastening of the driving side and the driven side is released. It has been.
[0023]
Next, a control configuration in this hybrid vehicle will be described.
As shown in FIGS. 1 and 2, a vehicle control unit 8 that manages and manages the overall operation of the vehicle, a motor control unit 9 that controls the operation of the electric motor 2 based on control information from the vehicle control unit 8, An engine control unit 12 that automatically adjusts the output of the engine 1 based on the control information from the vehicle control unit 8, specifically, the throttle opening of the electronic throttle valve 10 and the fuel injection amount by the injector 11, is provided. A potentiometer type accelerator operation amount detection sensor S1 for detecting the operation amount of the operation tool 13, a switch type brake operation detection sensor S2 for detecting whether or not the brake operation tool 14 is depressed, the rotational speed of the electric motor 2, In other words, the rotational speed sensor S3 as rotational speed detection means for detecting the rotational speed of the output shaft 1a of the engine 1 and the rotation of the axle of the wheel 3 are detected. Various detection information by the vehicle speed sensor S4 that detects the vehicle speed based on the speed, the shift position sensor S5 that detects the position of the shift position lever 17, the charge state detection unit S6 that detects the state of charge SOC of the battery 4, and the like are the vehicle control unit. 8 is input.
[0024]
As shown in FIG. 3, the motor control unit 9 controls the driving power supplied to the electric motor 2 by converting the DC power supplied from the battery 4 into three-phase AC power, or by regenerative operation. Inverter 28 that controls the regenerative power that is generated at 2 and supplied to battery 4, and the pulse drive signal that is pulse-width modulated (PWM) based on control information from vehicle control unit 8 is supplied to each switching transistor in inverter 28. PWM control circuit 29 and the like that are supplied to each of the base terminals of the battery, and by adjusting the magnitude of the current flowing through the electric motor 2 and the frequency of the alternating current, the drive torque and the rotational speed can be adjusted, and the battery The regenerative power charged to 4 can be adjusted.
[0025]
When a description is given of a configuration for generating mechanical braking force by operating the mechanical braking means KS by the brake operating tool 14, when the brake operating tool 14 is operated by a driver's stepping operation, A master cylinder 15 having a known configuration that generates a hydraulic operating force for braking corresponding to the stepping operating force is provided, and the vicinity of the wheel 3 is generated by the hydraulic operating force output from the master cylinder 15 through the hydraulic oil supply passage 15a. The vehicle body is braked by operating a friction braking device 16 provided on the vehicle. Such a mechanical braking means KS is configured to be adjustable so that the hydraulic operating force, that is, the mechanical braking force increases as the operating force of the driver with respect to the brake operating tool 14 increases. .
[0026]
The position of the shift position lever 17 includes “P” (parking position), “R” (reverse travel position), “N” (neutral position), and “D” (forward travel position). The switching operation is appropriately performed according to the situation.
[0027]
The vehicle control unit 8 includes information such as detection information of the shift position sensor S5, detection information of the accelerator operation amount detection sensor S1, detection information of the vehicle speed sensor S4, and charge amount information of the battery 4 by the charge state detection unit S6. Based on this, control information is commanded to the motor control unit 9 and the engine control unit 12. The vehicle control unit 8 switches and controls the engagement state of the lockup clutch 5a based on the throttle opening information of the electronic throttle valve 10 managed by the engine control unit and the detection information of the vehicle speed sensor S4. It is configured.
Therefore, the vehicle control unit 8, the motor control unit 9, and the engine control unit 12 respectively control the operation of the engine 1 and the electric motor 2, and control means H that controls the switching of the engagement state of the lockup clutch 5a is configured. Is done.
[0028]
Hereinafter, specific operations of each unit will be described.
First, the switching control of the engaged state of the lockup clutch 5a by the vehicle control unit 8 will be described. That is, the lock-up clutch 5a is controlled based on the throttle opening information of the electronic throttle valve 10 managed by the engine control unit 12 and the detection information of the vehicle speed sensor S4. Specifically, based on the map data set in advance as shown in FIG. 10, if each of the throttle opening and the vehicle speed is in the region indicated by the hatched lines in FIG. 10, the lockup clutch 5a is switched to the engaged state. The lock-up clutch 5a is configured to be switched to the engagement release state if it is in an area other than the shaded area.
[0029]
Next, control of the engine 1 and the electric motor 2 by the vehicle control unit 8 will be described. For example, when the shift position lever 17 is at “P” (parking position) or “N” (neutral position), the engine 1 is basically stopped and the power running operation and the regenerative operation by the electric motor 2 are not performed. However, when the state of charge of the battery 4 falls below the set amount and the battery 4 needs to be charged, the vehicle control unit 8 operates the engine 1 to transfer the power of the engine 1 to the electric motor 2. In order to control the operation of the engine 1 and the electric motor 2 so as to charge the battery 4 with the electric power generated by the regenerative operation, control information is instructed to the motor control unit 9 and the engine control unit 12.
[0030]
Further, when the shift position lever 17 is operated to “D” (forward travel position) and the forward direction is commanded as the vehicle body travel direction, the accelerator operation tool 13 is depressed to start the vehicle body. If the engine 1 is stopped at that time, the electric motor 2 is rotated to start the engine 1, and when the vehicle body travels forward, the output of the engine 1 is adjusted according to the accelerator operation amount, and the electric motor is operated as described later. The motor 2 is configured to instruct control information to the motor control unit 9 and the engine control unit 12 so that the power running operation and the regenerative operation are executed.
When the shift position lever 17 is operated to “R” (reverse travel position) and the reverse direction is commanded as the vehicle body travel direction, the output of the engine 1 is adjusted according to the accelerator operation amount. However, for the electric motor 2, neither power running operation nor regenerative operation is performed.
[0031]
Next, the power running operation and regenerative operation of the electric motor 2 will be described.
The power running operation and the regenerative operation of the electric motor 2 are performed by obtaining a target torque based on various types of information described later and controlling the operation of the electric motor 2 so as to generate the obtained target torque.
In other words, in the power running operation, control information corresponding to the target torque is given to the PWM control circuit 29 so that the electric motor 2 outputs the target torque in the same direction as the rotation direction of the engine 1, and PWM control is performed. A pulse signal corresponding to the target torque is applied from the circuit 29 to the base terminal of each switching transistor of the inverter 28, and the electric motor 2 assists the engine 1 with the target torque. In the regenerative operation, control information corresponding to the target torque is given to the PWM control circuit 29 so that the electric motor 2 outputs the target torque in the direction opposite to the rotation direction of the engine 1. The pulse signal corresponding to the target torque is applied to the base terminal of each switching transistor of the inverter 28, and the electric motor 2 acts to apply reverse torque, that is, regenerative braking force, to the engine 1. become. Then, the electric motor 2 is driven by the power of the engine 1 to act as a generator, and the battery 4 is charged in a state where the inverter 28 is changed and adjusted to the regenerative power corresponding to the regenerative braking force.
[0032]
Then, if the lock-up clutch 5a is in the disengaged state, the control means H outputs the travel drive torque obtained based on the travel drive information including information on the accelerator operation amount. If the operation is controlled and the lock-up clutch 5a is in the engaged state, the driving drive torque and the rotational speed of the engine 1 that are obtained based on the driving information including the information on the accelerator operation amount are increased per unit time. The operation of the electric motor 2 is controlled so as to output an increase correction torque obtained by adding the addition torque obtained based on the quantity information.
[0033]
That is, as the torque information for obtaining the target torque when performing the power running operation and the regenerative operation of the electric motor 2, the travel drive torque Tm obtained based on the travel drive information including information on the accelerator operation amount, In addition, there is an addition torque Tk that is obtained based on information on the amount of increase in the rotational speed of the engine 1 per unit time.
[0034]
First, how to determine the travel drive torque Tm will be described below.
A change characteristic of the travel driving torque Tm of the electric motor 2 with respect to a change in the rotational speed of the electric motor 2 is set in advance as a characteristic as shown in FIG. 4, and the vehicle control unit 8 is based on this characteristic. The travel driving torque Tm is obtained. The line q1 shown in FIG. 4 is for driving driving with respect to a change in rotational speed corresponding to the maximum (full open) accelerator operation amount when the charge state SOC of the battery 4 is high (hereinafter referred to as a full accelerator state). The change of torque Tm is shown. A line q2 indicates a change in the travel driving torque Tm corresponding to when the accelerator operation amount is minimized (fully closed) (hereinafter referred to as an accelerator off state). A line q3 indicates a change in the driving torque Tm with respect to a change in the rotational speed corresponding to the full accelerator state when the state of charge SOC of the battery 4 is low.
[0035]
Further, as shown in FIG. 6, a torque limiting rate for limiting the motor torque with respect to a change in the state of charge SOC of the battery 4 is set in advance. A line r1 in FIG. 6 indicates the torque limiting rate of the travel driving torque Tm of the electric motor 2 corresponding to the full accelerator state. That is, if the state of charge SOC of the battery 4 is higher than the lower threshold A0 as the set state of charge, the torque limit rate is a “positive” value, and the state of charge SOC of the battery 4 is higher than the upper threshold A2. If the battery is almost fully charged, the value is “+1”. At this time, the line q1 shown in FIG. 4 is applied as it is. If the state of charge SOC of the battery 4 is slightly reduced and the state of charge SOC of the battery 4 is lower than the upper threshold A2 and higher than the lower threshold A0, the torque limiting rate is a ratio smaller than “+1”. become. Then, the change characteristic which becomes low according to the ratio is applied to the line q1 in FIG.
If the state of charge SOC of the battery 4 is lower than the lower threshold A0, the limiting rate of the travel driving torque Tm of the electric motor 2 corresponding to the full accelerator state becomes a “negative” value. Is “−1”, the line q3 in FIG. 4 is the driving torque Tm of the electric motor 2 corresponding to the full accelerator state.
[0036]
A line r2 in FIG. 6 indicates the limiting rate of the travel driving torque Tm of the electric motor 2 corresponding to the accelerator off state. That is, if the state of charge SOC of the battery 4 is lower than the intermediate threshold value A1, the torque limiting rate becomes “+1” in almost all regions. At this time, the line q2 shown in FIG. It will be applied as it is. When the state of charge SOC of the battery 4 is higher than the intermediate threshold A1, the torque limiting rate is zero, and when the accelerator is off, the driving torque Tm of the electric motor 2 is always zero.
[0037]
Further, as shown in FIG. 5, a change characteristic for the output rate B, which is a change rate of the travel drive torque Tm when the accelerator operation amount is changed, is set in advance. That is, the output rate B is zero if the accelerator operation amount is zero, and the output rate B is 100% if the accelerator operation amount is the maximum value and is in the full accelerator state.
[0038]
From each characteristic as described above, the traveling drive torque Tm of the electric motor 2 is obtained as follows.
That is, from the characteristics shown in FIG. 4 to FIG. 6, the travel drive torque Tm in the full accelerator state and the travel drive torque Tm in the accelerator off state are obtained based on the detection information of the state of charge SOC of the battery 4. Based on the travel drive torque Tm and the change rate (output rate B) based on the detected value of the accelerator operation amount, the travel drive torque Tm corresponding to the rotation speed and the accelerator operation amount is obtained.
For example, if the state of charge SOC of the battery 4 is higher than the upper threshold A2, the driving torque Tm changes between the line q1 and zero as the accelerator operation amount changes, as shown in FIG. . If the output rate B of the accelerator operation amount is zero, the travel drive torque Tm is zero, and if the output rate B is 100%, the travel drive torque Tm is obtained as a value on the line q1. That is, the value on the line q1 corresponding to the rotation speed of the electric motor 2 detected by the rotation speed sensor S3 is determined, and the value varies between the value on the line q1 and zero according to the magnitude of the output rate B. Thus, the driving torque Tm is obtained.
If the state of charge SOC of the battery 4 is lower than the upper threshold value A2 and higher than the lower threshold value A0, as shown in FIG. 8, as the accelerator operation amount changes, the travel drive torque Tm becomes equal to the line q1 and the line q2. Therefore, the driving torque Tm is obtained from the output rate B of the accelerator operation amount between them as in the case where the upper threshold A2 is higher.
If the state of charge SOC of the battery 4 is lower than the lower threshold value A0, as shown in FIG. 9, the driving torque Tm changes between the line q2 and the line q3 as the accelerator operation amount changes. Therefore, the travel driving torque Tm is obtained from the output rate B of the accelerator operation amount between them. As is apparent from FIG. 9, if the state of charge SOC of the battery is lower than the lower threshold value A0, the electric motor 2 always performs only the regenerative operation.
[0039]
When the above relationship is expressed by a mathematical expression, it can be expressed as follows.
Torque indicated by line q1 is q1, torque indicated by line q2 is q2, torque indicated by line q3 is q3, torque limiting rate indicated by line r1 is r1, torque limiting rate indicated by line r2 is r2, accelerator When the output rate of the operation is B, when the state of charge SOC of the battery 4 is higher than the lower threshold value A0, the travel driving torque Tm of the electric motor 2 can be expressed by the following equation (1).
[0040]
[Expression 1]
Tm = (r1 * q1-r2 * q2) * B / 100 + r2 * q2
(SOC ≧ A0)
[0041]
Further, when the state of charge SOC of the battery 4 is lower than the lower threshold value A0, the traveling driving torque Tm of the electric motor 2 can be expressed by the following equation 2.
[0042]
[Expression 2]
Tm = (-r1 * q3-r2 * q2) * B / 100 + r2 * q2
(SOC <A0)
[0043]
In the characteristics shown in FIG. 4, the positive (+) side that is above zero indicates that the torque is in a direction that assists the rotational direction of the engine 1, and the torque increases toward the upper side in the figure. The negative (−) side that is lower than zero indicates that the torque is in the direction opposite to the rotation direction of the engine 1, that is, the regenerative torque, and the regenerative torque becomes larger toward the lower side in the figure.
[0044]
Next, a description will be given of how to obtain the addition torque Tk that is obtained based on the information on the increase amount per unit time of the rotational speed of the engine 1.
The addition torque Tk is obtained as a value that increases as the increase amount per unit time to the increase side of the rotation speed of the engine 1 increases based on the detection information of the rotation speed of the engine 1. Specifically, as shown in FIG. 11, the change characteristic of the torque for addition Tk with respect to the amount of increase in the rotational speed of the engine 1 per unit time is set in advance. It is set so that the addition torque Tk becomes larger as the increase amount per time is larger. Then, based on the detection information of the rotational speed of the engine 1 detected by the rotational speed sensor S3, an increase amount per unit time of the rotational speed of the engine 1 is obtained, and the addition torque Tk is calculated from the characteristics shown in FIG. Ask.
[0045]
Next, based on the flowchart shown in FIG. 12, the shift operation position of the shift position lever 17 is at “D” (forward travel position) and forward travel is commanded, and the battery state of charge SOC is lower threshold A0. The motor control operation when it is larger than the above will be described.
First, it is determined whether or not the lock-up clutch 5a is in an engaged state, that is, whether it is in an engaged state or in an unreleased state (step 1), and the determination result is negative, that is, the lock-up clutch 5a is released from engagement. When it is determined that the vehicle is in the state, the driving torque Tm of the electric motor 2 is obtained by the calculation method as described above, and the driving torque Tm is set as the target torque (step 2).
[0046]
When it is determined in step 1 that the lockup clutch 5a is engaged, the travel driving torque Tm of the electric motor 2 is obtained by the above-described computation method, and the addition torque Tk is obtained by the above-described computation method. Then, the traveling correction torque Tm and the addition torque Tk are added to obtain an increase correction torque, and the increase correction torque is set as a target torque (steps 3, 4, and 5).
[0047]
When the target torque is obtained as described above, the operation of the electric motor 2 is controlled so as to output the target torque. That is, it is determined whether the target torque is “positive” or “negative”. If the target torque is “positive”, the power running operation is executed, and the traveling drive torque Tm is “ If it is not “positive” but “negative”, the regenerative operation is executed (steps 6, 7, 8).
[0048]
Thus, when the lock-up clutch 5a is in the engaged state, a larger torque is output by adding the addition torque Tk obtained based on the information on the increase amount per unit time of the rotational speed of the engine 1. The drive energy of the engine 1 for rotating the inertial mass of the rotating part that rotates integrally with the rotation of the engine 1 such as the flywheel, the crank, and the drive side rotating body of the torque converter can be reduced, The fuel consumption can be reduced accordingly.
[0049]
According to the experiment results of the present applicant, when the lock-up clutch 5a is in the engaged state, as shown in FIG. 13, no pulsating torque is generated and a stable running state is obtained. In FIG. 13, (1) is the engine speed, (2) is the vehicle speed, (3) is the travel drive torque, (4) is the accelerator operation amount, and (6) is the addition torque and travel drive. The time-dependent change state of each increase correction torque obtained by adding the torque is shown.
[0050]
[Another embodiment]
Hereinafter, other embodiments are listed.
[0051]
(1) In the above-described embodiment, when the addition torque is obtained as a value that increases as the increase amount of the engine speed per unit time increases as shown in FIG. Although the configuration is such that the addition torque is obtained according to such characteristics, the invention is not limited to such a configuration. For example, the addition torque changes linearly with respect to the increase amount of the engine speed per unit time. Or you may make it obtain | require the torque for addition according to the characteristic etc. which change in steps. Further, when the increase amount per unit time to the increase side of the engine speed is smaller than the set value, the addition torque is set to zero, and when the increase amount per unit time is larger than the set value, the addition is performed. The present invention can be implemented in various forms such as a configuration in which a constant value is set as the use torque.
[0052]
(2) In the above embodiment, the hybrid vehicle having the configuration in which the output shaft of the driving drive engine and the driving drive electric motor are directly connected has been illustrated, but instead of such a configuration, as shown in FIG. The engine 1 and the electric motor 2 for running the vehicle are provided with a drive unit KU that is connected via a planetary gear mechanism 30, and a transmission with a torque converter is used as the power of the drive unit KU having such a configuration. It is good also as a structure transmitted to a traveling apparatus via.
[0053]
(3) Map data as shown in FIG. 10 for switching various engagement characteristics as shown in FIG. 4 to FIG. 9 when obtaining the driving torque in the above embodiment and the engagement state of the lock-up clutch. This is an example, and the present invention is not limited to the characteristics shown in the drawings, and may be implemented with appropriate modifications.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a hybrid vehicle
FIG. 2 is a control block diagram.
FIG. 3 is a diagram showing a control configuration of an electric motor.
FIG. 4 is a characteristic diagram of the driving torque for the electric motor.
FIG. 5 is a diagram showing an output rate corresponding to an accelerator operation amount;
FIG. 6 is a diagram showing a torque limiting rate
FIG. 7 is a characteristic diagram of torque for driving the electric motor when the state of charge of the battery is higher than the upper threshold value.
FIG. 8 is a characteristic diagram of the driving torque of the electric motor when the state of charge of the battery is lower than the upper threshold and higher than the lower threshold.
FIG. 9 is a characteristic diagram of torque for driving the electric motor when the state of charge of the battery is lower than the lower threshold.
FIG. 10 is a diagram showing map data for controlling the lock-up clutch.
FIG. 11 is a diagram showing a change characteristic for obtaining an addition torque.
FIG. 12 is a flowchart of the control operation.
FIG. 13 is a time chart based on experimental results.
FIG. 14 is a diagram showing a schematic configuration of a hybrid vehicle according to another embodiment.
FIG. 15 is a time chart based on experimental results.
[Explanation of symbols]
1 engine
2 Electric motor
5 Torque converter
5a Lock-up clutch
6 Transmission
H Control means

Claims (2)

An engine, an electric motor that assists the engine, a transmission with a torque converter, a lockup clutch for the torque converter, an operation of the engine and the electric motor, and an engagement state of the lockup clutch And a hybrid vehicle equipped with a control means for switching and controlling
The control means is
If the lock-up clutch is in a disengaged state, the operation of the electric motor is controlled so as to output a traveling drive torque obtained based on the traveling drive information including information on the accelerator operation amount,
If the lock-up clutch is in the engaged state, the travel drive torque obtained based on the travel drive information including the information on the accelerator operation amount and the information on the increase amount per unit time of the rotation speed of the engine are used. A hybrid vehicle configured to control the operation of the electric motor so as to output an increase correction torque obtained by adding the addition torque obtained in this manner. The control means is
The hybrid vehicle according to claim 1, wherein the torque for addition is calculated as a value that increases as the amount of increase in the rotational speed of the engine per unit time increases.

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