JP2018030443A - Hybrid vehicular control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid vehicular control apparatus capable of suppressing a delay in response and/or a difference in acceleration response that are caused by engine torque being absorbed by a damper mechanism with a variable torsional characteristic.SOLUTION: In a control apparatus of a hybrid vehicle Ve that includes a damper mechanism with which a relation between input torque and a torsional angle between an input member and an output member caused by the torque is nonlinear, a controller causes a motor to output compensation torque α,β for compensating for torque absorbed by the damper mechanism, where, in the case of a rate of change amount of the torsional angle relative to the change amount of the torque being higher than a given rate, the compensation torque α,β is set higher than in the case of the rate being equal to or lower than the given rate.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control apparatus for a hybrid vehicle configured to attenuate fluctuations in torque output from an engine by a damper mechanism that changes torsional characteristics.

  Patent Document 1 describes a clutch disk provided between an engine and a transmission in a power transmission path. In the clutch disk described in Patent Document 1, an input unit to which engine torque is input and an output unit that transmits the input torque to a transmission are connected via a damper mechanism. The damper mechanism includes a spring, and the amount of compression of the spring changes as the input torque fluctuates. As a result, the input portion and the output portion are twisted. As a result, torque fluctuation is reduced or reduced. Is done.

  The damper mechanism described in Patent Document 1 includes a small-diameter coil spring and a large-diameter coil spring that are cylindrical coil springs, and an assist spring that is a torsion coil spring. These large-diameter coil springs, assist springs, and small-diameter coil springs have smaller spring constants in the order described here. When the twist angle between the input unit and the output unit is within the first predetermined angle range, only the small-diameter coil spring is compressed, and when the torsion angle is within the second predetermined angle range larger than the first predetermined angle range, The large-diameter coil spring and the assist spring are also configured to be compressed.

JP 2014-228124 A

  In the damper mechanism that attenuates torque fluctuations by compressing the spring, such as the damper mechanism described in Patent Document 1, when the torque input to the input unit is transmitted to the output unit, the spring The torque is absorbed by the damper mechanism in accordance with the compression amount. That is, when the input torque increases, the output torque becomes smaller than the input torque until the compression amount of the spring built in the damper mechanism and the reaction force accompanying the compression amount are balanced with the input torque. For this reason, when the spring constant of the spring compressed by the damper mechanism is small, the amount of compression of the spring increases, so that the transmission response of torque of the transmission device or transmission including the damper mechanism deteriorates. Therefore, for example, a response delay may occur with respect to the acceleration request, or there may be a difference in the time required for the vehicle to accelerate.

  The present invention has been made by paying attention to the above technical problem, and it shows that there is a difference in response delay and acceleration response caused by absorption of the engine torque by a damper mechanism whose torsional characteristics change. It is an object of the present invention to provide a control device for a hybrid vehicle that can be suppressed.

  In order to achieve the above object, the present invention provides a damper having an engine, an input member to which torque output from the engine is input, and an output member that outputs torque input to the input member to driving wheels. And a motor capable of transmitting torque to the drive wheel without passing through the damper mechanism. The damper mechanism includes a torque input to the input member, the input member generated by the torque, and the output. A controller for controlling the motor in a hybrid vehicle control device configured so that a relationship between a torsion angle with a member is nonlinear and configured to attenuate a variation in torque output from the engine by the damper mechanism And the controller absorbs the torque absorbed by the damper mechanism while increasing the output torque of the engine. A compensation torque for compensating the torque is output from the motor, and the compensation torque is obtained when the ratio of the change amount of the torsion angle to the change amount of the torque is higher than a predetermined ratio. The present invention is characterized in that the ratio of the change amount of the twist angle is made larger than that in the case of the predetermined ratio or less.

  According to the present invention, while the output torque of the engine is being increased, the ratio of the change amount of the torsion angle between the input member and the output member to the change amount of the torque input to the input member is changed and inputted. The relationship between torque and torsion angle becomes nonlinear. When the output torque of the engine is increased, the torque is absorbed by the twist generated in the damper mechanism, and the increase in torque at the output member of the damper mechanism is delayed. The controller is configured to compensate the torque absorbed by such a damper mechanism with a motor. Therefore, even if the output torque of the engine is not immediately transmitted to the drive wheels due to a response delay in the damper mechanism while increasing the output torque of the engine, the motor outputs a compensation torque, so that the drive force is compensated. be able to. In that case, the controller compensates when the ratio of the change amount of the torsion angle with respect to the change amount of the torque is higher than the predetermined ratio than when the ratio of the change amount of the torsion angle with respect to the change amount of the torque is less than the predetermined ratio. Increase the torque. In other words, when the torque absorbed by the damper mechanism is relatively large, a larger compensation torque is output. Therefore, even if there is a difference in torque transmission response in the damper mechanism due to different torsional characteristics, the vehicle It is possible to suppress or avoid the occurrence of a difference in acceleration responsiveness.

It is a figure which shows an example of the gear train of the hybrid vehicle carrying the power transmission device made into object by this invention. It is a figure for demonstrating the characteristic of the damper mechanism in embodiment of this invention. It is a flowchart for demonstrating the example of control performed by embodiment of this invention. FIG. 4 is a time chart for explaining an example of changes in accelerator opening, motor output torque, input shaft torque, and vehicle acceleration when the control example of FIG. 3 is executed.

  The present invention will be described with reference to the drawings. FIG. 1 shows an example of a hybrid vehicle equipped with a power transmission device to which a control device according to the present invention is applied. A hybrid vehicle Ve (hereinafter also referred to as a vehicle) Ve shown in FIG. 1 includes a plurality of driving force sources for the engine 1, the first motor 2, and the second motor 3. The vehicle Ve is configured to divide and transmit the power output from the engine 1 to the first motor 2 side and the drive shaft 5 side by the power split mechanism 4. Further, the power generated by the first motor 2 is supplied to the second motor 3, and the driving force output from the second motor 3 can be applied to the drive shaft 5 and the drive wheels 6. In the following description, the first motor and the second motor may be collectively referred to as motors 2 and 3.

  The power split mechanism 4 transmits torque between the engine 1 and the first motor 2 and the drive wheels 6, and is constituted by a planetary gear mechanism having a sun gear 7, a ring gear 8, and a carrier 9. In the example shown in FIG. 1, a single pinion type planetary gear mechanism is used. On the concentric circle of the sun gear 7 of the planetary gear mechanism, an internal gear ring gear 8 is arranged. A pinion gear 10 meshed with the sun gear 7 and the ring gear 8 is held by a carrier 9 so as to be able to rotate and revolve.

  The power split mechanism 4 is disposed on the same axis as the engine 1 and the first motor 2, and the input shaft of the power split mechanism 4 is connected to the carrier 9 of the planetary gear mechanism constituting the power split mechanism 4. 4a is connected. The flywheel 11 and the output shaft 1a of the engine 1 are connected to the input shaft 4a. Specifically, the output shaft 1 a and the input shaft 4 a are connected via a damper mechanism 12 and a torque limiter 13 attached to the flywheel 11. The torque limiter 13 is a mechanism for limiting the magnitude of torque transmitted between the drive wheels 6 and the engine 1.

  The damper mechanism 12 is composed of, for example, a spring damper, and a torsion spring or a cylindrical coil spring is disposed between a drive side (input side) input member (not shown) and a driven side (output side) output member. . Therefore, when torque is input to the damper mechanism 12, the respective members rotate relatively to compress the springs 12a. The vibration is attenuated by changing the amount of compression of the spring 12a as the input torque fluctuates. The springs 12a are provided with a plurality of types of coil springs and torsion springs having different lengths and spring constants. That is, the damper mechanism 12 is configured such that the relationship between the input torque and the twist angle between the input member and the output member generated by the torque is non-linear.

  Specifically, the damper mechanism 12 of this embodiment is configured such that the magnitude of the spring constant obtained by combining one or a plurality of springs is two stages (K1 <K2). In other words, the damper mechanism 12 is small when the input torque is smaller than a predetermined torque or when the twist angle between the input member and the output member is smaller than a predetermined twist angle. An elastic action is generated with the spring constant K1. When the input torque is equal to or greater than a predetermined torque, or when the torsion angle between the input member and the output member is equal to or greater than the predetermined torsion angle, an elastic action is generated with the larger spring constant K2. It is configured. FIG. 2 shows these relationships, with the vertical axis representing the engine torque and the horizontal axis representing the torsion angle between the input member and the output member in the damper mechanism. Hereinafter, for convenience of explanation, a state in which the spring constant in the damper mechanism 12 is the first spring constant K1 is referred to as a state in which the small-diameter spring 12a is acting, and the spring constant in the damper mechanism 12 is the second spring constant K2. This state is referred to as a state in which the large-diameter spring 12a is acting.

  The first motor 2 is connected to the sun gear 7 of the planetary gear mechanism. The first motor 2 is disposed adjacent to the power split mechanism 4 on the side opposite to the engine 1. A rotor shaft 2 b that rotates integrally with the rotor 2 a of the first motor 2 is connected to the sun gear 7. The rotating shafts of the rotor shaft 2b and the sun gear 7 are hollow shafts. In the hollow portions of the rotor shaft 2b and the rotation shaft of the sun gear 7, a rotation shaft of an oil pump (not shown) is arranged. That is, the rotating shaft is connected to the input shaft 4a through the hollow portion.

  A first drive gear 14 as an external gear is formed integrally with the ring gear 8 on the outer peripheral portion of the ring gear 8 of the planetary gear mechanism. A counter shaft 15 is disposed in parallel with the rotation axis of the power split mechanism 4 and the first motor 2. A counter driven gear 16 that meshes with the first drive gear 14 is attached to one end of the counter shaft 15 so as to rotate integrally. On the other hand, a counter drive gear 17 is attached to the other end of the counter shaft 15 so as to rotate integrally with the counter shaft 15. The counter drive gear 17 meshes with a diff ring gear 19 of a differential gear 18 that is a final reduction gear. Accordingly, the ring gear 8 of the power split mechanism 4 is connected to the drive shaft 5 via the output gear train 20 including the first drive gear 14, the counter shaft 15, the counter driven gear 16, the counter drive gear 17, and the diff ring gear 19. And it is connected with the drive wheel 6 so that power transmission is possible.

  The power transmission device of the vehicle Ve is configured so that the torque output from the second motor 3 can be added to the torque transmitted from the power split mechanism 4 to the drive shaft 5 and the drive wheels 6. . Specifically, a rotor shaft 3 b that rotates integrally with the rotor 3 a of the second motor 3 is disposed in parallel with the counter shaft 15. A second drive gear 21 that meshes with the counter driven gear 16 is attached to the tip of the rotor shaft 3b so as to rotate integrally. Therefore, the second motor 3 is connected to the ring gear 8 of the power split mechanism 4 via the output gear train 20 and the second drive gear 21 as described above so that power can be transmitted. That is, the ring gear 8 is coupled to the drive shaft 5 and the drive wheels 6 through the output gear train 20 together with the second motor 3 so as to be able to transmit power.

  The vehicle Ve configured in this manner travels by driving a hybrid travel mode (HV mode) using the engine 1 as a power source, the first motor 2 and the second motor 3 with electric power of a power storage device (not shown). Driving modes such as an electric driving mode (EV mode) are possible. Such control for setting and switching each mode is executed by an electronic control unit (ECU) 22. The ECU 22 corresponds to the controller in the present invention, is configured mainly with a microcomputer, performs calculations using input data, data stored in advance, and programs, and uses the calculation results as control command signals. It is configured to output. The input data includes vehicle speed, accelerator opening, engine 1 rotation speed, engine 1 output torque, motor 2 and 3 output torque, ambient temperature, power storage device remaining charge (SOC), damper mechanism 12 The torsion angle between the input member and the output member, and the map shown in FIG. 2 is stored in advance. The ECU 22 outputs a start / stop command signal for the engine 1, a torque command signal for the first motor 2, a torque command signal for the second motor 3, a torque command signal for the engine 1, etc. as control command signals.

  The vehicle Ve configured as described above may be accelerated by increasing the output torque of the engine 1 by satisfying a predetermined condition such as an increase in required driving force. During the acceleration transition period, while the output torque of the engine 1 is increased, the compensation torques α and β for compensating the torque absorbed by the damper mechanism 12 are output from the motors 2 and 3. ing. FIG. 3 is a flowchart showing an example of the control. Specifically, when the torque output from the engine 1 is increased as the accelerator opening increases during traveling, the compensation torque α is supplied from the second motor 3. , Β is an example of control when outputting. The following control is executed by the ECU 22.

  First, the ECU 22 detects an acceleration request (accelerator opening) from the driver (step S1). The acceleration request is determined based on, for example, the depression amount of the accelerator pedal operation by the driver. When the output torque of the engine 1 is increased based on the acceleration request, the magnitude of the torque that the engine 1 is currently outputting is detected (confirmed) (step S2). When the magnitude of the torque output from the engine 1 is confirmed, the map shown in FIG. 2 is confirmed (step S3).

  As described above, this map takes the torque input to the damper mechanism 12 on the vertical axis and the torsion angle between the input member and the output member on the horizontal axis, and the damper mechanism 12 according to the magnitude of the torque and torsion angle. This specifies the spring constant at. Therefore, the magnitude of the spring constant in the damper mechanism 12 can be specified by detecting the output torque of the engine 1. Then, when the magnitude of the spring constant is specified, it is determined whether the spring constant is the first spring constant K1 or the second spring constant K2 (step S4). When the damper mechanism 12 is operated by the large-diameter spring 12a and the spring constant of the damper mechanism 12 is the second spring constant K2 (YES in step S4), the first compensation output from the second motor 3 is performed. The magnitude of the torque α is determined (step S5).

  In the state where the large-diameter spring 12a is acting on the damper mechanism 12, the torque transmission response in the damper mechanism 12 is better than the state where the small-diameter spring 12a is acting. However, the engine 1 requires a longer time to increase the output torque than the motors 2 and 3. For this reason, even if the large-diameter spring 12a having relatively good response is acting on the damper mechanism 12, the first motor 3 outputs the driving force according to the accelerator opening to the driving wheel 6 immediately. The compensation torque α is output. The first compensation torque α is the amount of compression of the large-diameter spring 12a, the rate of increase of the output torque of the engine 1, the magnitude of the second spring constant K2, the accelerator opening, the vehicle speed, the engine speed, the ambient temperature, the power storage device Is determined based on factors such as the remaining battery level or the current output torque of the motors 2 and 3.

  On the other hand, when it is determined in step S4 that the small-diameter spring 12a is acting on the damper mechanism 12 and the spring constant is the first spring constant K1 (NO in step S4), the second motor 3 is The magnitude of the second compensation torque β to be output is determined (step S6). In the state where the small-diameter spring 12a is acting on the damper mechanism 12, compared to the state where the large-diameter spring 12a is acting, more torque is absorbed by the damper mechanism 12, so the second compensation torque β is 1 It is configured to be larger than the compensation torque α (α <β). That is, when the torque input to the damper mechanism 12 is smaller than a predetermined torque at which the spring constant in the damper mechanism 12 is switched, a larger compensation torque is output as compared with a case where the torque is greater than the predetermined torque. ing. Similarly to the first compensation torque α, the second compensation torque β is the compression amount of the small diameter spring 12a, the rate of increase of the output torque of the engine 1, the magnitude of the first spring constant K1, the accelerator opening, the vehicle speed, and the engine speed. It is determined based on factors such as the ambient temperature, the remaining battery level of the power storage device, or the current output torque of the motors 2 and 3.

  When the first compensation torque α or the second compensation torque β is determined by the control described above, the second motor 3 adds to the torque corresponding to the accelerator request or the requested driving force to obtain the first compensation torque α or the second compensation torque. Torque β is output (step S7). These compensation torques α and β are output for a predetermined time until the increased output torque of the engine 1 is transmitted to the drive wheels 6. After the predetermined time elapses, the second motor 3 reduces the torque output by the compensation torques α and β to complete this control. In the above-described configuration, both compensation torques α and β are configured to be output from the second motor 3. However, the present invention is not limited to this configuration, and the motor that outputs the second compensation torque β uses either the first motor 2 or the second motor 3 or either the first motor 2 or the second motor 3. And may be determined according to the driving mode or the like.

  In the control described above, the determined compensation torques α and β are output from the motors 2 and 3, but depending on the magnitude of the output torque, the determined compensation torques α and β are output from the motor. 2 and 3 may not be output. In such a case, the torque output to the drive wheels 6 may be compensated within the possible range by outputting the maximum torque that can be output by the motors 2 and 3.

  Next, with reference to FIG. 4, the above control example will be described using a time chart. FIG. 4 shows a state in which any one of the springs 12a is acting in the damper mechanism 12, and when the output torques of the motors 2, 3 and the engine 1 are increased in the acceleration transition period as the accelerator opening increases. It is a time chart. In FIG. 4, the small-diameter spring 12 a is acting on the damper mechanism 12 and the second compensation torque β is output, and the large-diameter spring 12 a is acting on the damper mechanism 12 and the first compensation torque α is Control is performed so that the acceleration of the vehicle Ve changes in the same way when output. 4 indicates the case where the second compensation torque β is output in a state where the small-diameter spring 12a is acting on the damper mechanism 12, and the alternate long and short dash line indicates the large-diameter spring 12a in the damper mechanism 12. The case where the 1st compensation torque (alpha) is output in the state which is acting is shown.

  As shown in FIG. 4, when the accelerator opening is increased by the driver's operation, the torque output from the motors 2 and 3 and the engine 1 (not shown) is increased accordingly (at time t1). The torque increased by the motors 2 and 3 at this time is a torque that does not include the compensation torques α and β described above. On the other hand, although the output torque of the engine 1 is gradually increasing, since the small-diameter spring 12a and the large-diameter spring 12a are acting in the damper mechanism 12, the output torque of the engine 1 is reduced to the input shaft 4a at time t1. And hardly transmitted to the drive wheel 6. Therefore, the acceleration of the vehicle Ve at time t1 is increased by an amount corresponding to the torque output from the motors 2 and 3 and not including the compensation torques α and β.

  When it is determined that the small-diameter spring 12a is acting on the damper mechanism 12, the ECU 22 controls the motors 2 and 3 to output the second compensation torque β. On the other hand, when it is determined that the large-diameter spring 12a is operating, the motors 2 and 3 are controlled to output the first compensation torque α (at time t2). That is, the motors 2 and 3 output torque obtained by adding the compensation torques α and β determined based on the above-described elements to the torque output according to the accelerator opening and the required driving force. Therefore, the acceleration of the vehicle Ve is obtained by adding the compensation torques α and β to the torque output from the motors 2 and 3, that is, the acceleration of the vehicle Ve can be made an acceleration corresponding to the accelerator opening. . At this time, the torque of the input shaft 4a gradually increases as the torque of the engine 1 is transmitted.

  Then, after outputting the compensation torques α and β for a predetermined time, the motors 2 and 3 reduce the torque output by the compensation torques α and β (at time t3). While the motors 2 and 3 output the compensation torques α and β, the output torque of the engine 1 transmitted to the drive wheels 6 gradually increases, so that the output torque is reduced by the compensation torques α and β. However, the acceleration according to the accelerator opening can be maintained.

  When the input torque of the damper mechanism 12 increases, the output torque of the damper mechanism 12 is the input torque until the amount of compression of the spring 12a built in the damper mechanism 12 and the reaction force associated therewith match the input torque. The torque is smaller. Therefore, the time for which the motors 2 and 3 output the compensation torques α and β is determined by the compression length of the spring 12 a and the magnitude of the torque input to the damper mechanism 12.

  As described above, in the embodiment of the present invention, the motors 2 and 3 are configured to compensate the torque absorbed by the damper mechanism 12 while the output torque of the engine 1 is increased. Therefore, even if the output torque of the engine 1 is not immediately transmitted to the drive wheels 6 due to a response delay in the damper mechanism 12 during the acceleration transition period, the motors 2 and 3 output the compensation torques α and β. Can be supplemented. In this case, the ECU 22 increases the compensation torques α and β output from the motors 2 and 3 as the ratio of the change amount of the torsion angle to the change amount of the torque increases, that is, as the spring constant in the damper mechanism 12 decreases. As described above, even if there is a difference in torque transmission response in the damper mechanism 12 by controlling the compensation torques α and β so that the change in the acceleration of the vehicle Ve is the same. Thus, it is possible to suppress or avoid the occurrence of a difference in acceleration response in the vehicle Ve.

  Although a plurality of embodiments of the present invention have been described above, the present invention is not limited to the above-described example, and may be appropriately changed within the scope of achieving the object of the present invention. For example, the above control is applied to a hybrid vehicle having a damper mechanism that uses more springs of different lengths and types, or uses a non-linear spring such as a conical coil spring, an unequal pitch coil spring, or a taper coil spring. can do. That is, as shown in FIG. 2, when the vertical axis represents the torque input to the input member and the horizontal axis represents the torsion angle between the input member and the output member, a part or all of the gradient is non-linear. Any hybrid vehicle having such a damper mechanism can be applied. Even in such a case, the compensation torque output from the motor is the amount of compression of the spring, the rate of increase of the engine output torque, the magnitude of the spring constant, the accelerator opening, the vehicle speed, the engine speed, the ambient temperature, the battery of the power storage device. It can be determined based on factors such as the remaining amount or the current output torque of the motor.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... 1st motor, 3 ... 2nd motor, 6 ... Drive wheel, 22 ... Electronic control unit (controller), Ve ... Vehicle, (alpha), (beta) ... Compensation torque.

Claims (1)

Engine,
A damper mechanism having an input member that receives torque output from the engine and an output member that outputs torque input to the input member to drive wheels;
A motor capable of transmitting torque to the drive wheel without using the damper mechanism;
The damper mechanism is configured such that a relationship between a torque input to the input member and a torsion angle between the input member and the output member generated by the torque is non-linear, and the engine outputs the damper mechanism. In a hybrid vehicle control device configured to attenuate torque fluctuations,
A controller for controlling the motor;
The controller is
While increasing the output torque of the engine, a compensation torque for compensating the torque absorbed by the damper mechanism is output from the motor,
When the ratio of the change amount of the twist angle to the change amount of the torque is higher than a predetermined ratio, the ratio of the change amount of the twist angle to the change amount of the torque is equal to or less than the predetermined ratio. It is comprised so that it may become larger than this. The hybrid vehicle control apparatus characterized by the above-mentioned.

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