JP2015189323A - Vehicle power transmission mechanism control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably and promptly disengage SOWC without unnecessary power consumption and generating shock.SOLUTION: A control device of a vehicle power transmission mechanism in which an engine and a motor are connected to a differential mechanism producing differential action by a plurality of rotating elements, and a selectable one-way clutch (SOWC) including an engagement mechanism is provided between one rotating element other than the rotating element connected to the engine among the rotating elements and a predetermined fixed portion, applies a torque from the motor in an opposite direction to a direction in which the SOWC restricts the rotation of the other rotating element in a case of switching the engagement mechanism from an engaged state to a disengaged state, increases the torque of the motor up to a preset intended value, and increases an increase rate in an initial period of starting increasing the torque of the motor from an increase rate in a final period in which the torque of the motor is closer to the intended value.

Description

  The present invention relates to an apparatus for controlling a mechanism for transmitting power for traveling of a vehicle, and more particularly to a control apparatus for a power transmission mechanism including a selectable one-way clutch.

  Japanese Patent Application Laid-Open Publication No. 2004-228667 describes a vehicle transmission provided with a selectable one-way clutch (hereinafter referred to as SOWC). The SOWC has a pair of rings arranged opposite to each other, and one ring is provided with a strut that protrudes toward the other ring, and the other ring has a leading end of the strut inserted therein. Engaging pockets are provided. The strut is accommodated in a through hole formed in one ring, and the protruding teeth inserted into the through hole from the back side of the one ring (the side opposite to the surface facing the other ring). It is configured to be pushed out to the pocket side through a spring. A selector plate having a window hole through which the strut passes is disposed between the rings so as to rotate by a predetermined angle.

  In a state where the strut is pressed to the other ring side by the elastic force of the spring, the selector plate rotates and its window hole coincides with the through-hole (that is, the strut) in the rotation direction. It protrudes to the ring side of the ring and engages with a pocket formed in the other ring. The selector plate is rotated by frictional force caused by contacting the front surface of the other ring. In addition, when the projecting teeth are retracted while the strut is engaged with the pocket, the strut is not pressed to the pocket side, but the strut is engaged with the pocket by the frictional force between the strut and the pocket. Maintain state. The load that presses the selector plate against the other ring decreases as the protruding teeth move backward. On the other hand, since a spring for rotating the selector plate is arranged between the one ring and the selector plate, the selector plate is rotated by an elastic force when the protruding teeth are retracted, and the window hole Deviates from the strut position. That is, the strut is pushed into the through hole by the selector plate and is released from the pocket, and as a result, the SOWC is switched to the released state.

US Patent Application Publication No. 2009/0084653

  The SOWC described in Patent Document 1 is a so-called meshing clutch. In a state where the strut is engaged with the pocket, a frictional force acts between the two and the movement of the strut is restricted. When the SOWC is used as a brake and the brake is quickly released, it is conceivable that a torque is applied to a member whose rotation is stopped by the SOWC by a predetermined motor so as to eliminate the frictional force. The motor torque may be increased to some extent in order to reliably release the SOWC, but this may consume more power than necessary. Further, if the motor torque is excessive, there is a possibility that the member whose rotation has been stopped by the SOWC is suddenly rotated or a shock is caused accordingly. On the other hand, if the motor torque is slowly increased, excessive power consumption and motor torque can be avoided or suppressed, while the SOWC release takes time and the control responsiveness deteriorates. In this case, drivability may be deteriorated.

  The present invention has been made paying attention to the above technical problem, and an object of the present invention is to provide a control device for a vehicle power transmission mechanism capable of reliably releasing a selectable one-way clutch without causing a delay. It is what.

  To achieve the above object, according to the present invention, an engine and a motor are connected to a differential mechanism that generates a differential action by a plurality of rotating elements, and the first member and the second member that can rotate relative to each other are reversed. A selectable one-way clutch having an engagement mechanism that switches between an engagement state that restricts relative rotation in only one direction and a release state that allows relative rotation in both forward and reverse directions of the first member and the second member. A control device for a vehicle power transmission mechanism provided between a predetermined rotating portion and another rotating element different from the rotating element to which the engine is coupled among the plurality of rotating elements, the engaging mechanism When switching the engagement state from the engagement state to the release state, a torque in a direction opposite to the direction in which the rotation is restricted by the selectable one-way clutch is applied to the other rotation element by the motor. At the same time, the torque of the motor is increased to a predetermined target value, and the initial increase rate at which the motor torque has started to increase is made larger than the increase rate at the end when the torque of the motor approaches the target value. It is characterized by.

  According to the present invention, when the selectable one-way clutch is switched from the engaged state to the released state, so-called release direction torque is applied to the other rotating elements by the motor in order to reduce the load applied to the engagement mechanism. . The motor torque is initially increased at a large increase rate, and the torque increase rate is reduced at the end when the torque is close to the target value. As a result, the time to reach the target value is shortened, the motor torque can be matched with the target value without excess or deficiency, and therefore the selectable one-way clutch can be reliably released and unnecessary power consumption is achieved. In addition, it is possible to prevent or suppress the rotational speed of the other rotational elements from increasing rapidly and excessively.

It is a skeleton figure which shows an example of the power transmission mechanism which can be made into object by this invention. It is a collinear diagram about the planetary gear mechanism that constitutes the power split mechanism. It is a skeleton figure which shows the other example of the power transmission mechanism which can be made into object by this invention. It is a collinear diagram about the compound planetary gear mechanism constituting the power split mechanism and the overdrive mechanism. It is typical sectional drawing which shows the structure of the engaging mechanism in the selectable one-way clutch which can be made into object by this invention. It is a typical fragmentary figure which shows the accommodating part currently formed in the 1st clutch board, and the pocket currently formed in the 2nd clutch board. It is a flowchart for demonstrating an example of the control performed with the control apparatus which concerns on this invention. It is a time chart which shows an example of the change of the number of rotations of negative differential rotation, and the torque of the 1st motor at the time of performing the control.

  Since the present invention can be applied to a control device intended for a power transmission mechanism in a hybrid vehicle, first, an example of the power transmission mechanism will be described. FIG. 1 schematically shows a power transmission mechanism in a double-shaft two-motor type hybrid vehicle. As a driving force source, an engine (Eng) 1 and a power generation function corresponding to the motor in the present invention are shown. 1 motor (MG1) 2 and a second motor (MG2) 3 having a power generation function. The first motor 2 mainly controls the rotational speed of the engine 1 and cranks the engine 1, and is coupled together with the engine 1 to a power split mechanism 4 corresponding to a differential mechanism in the present invention.

  In the example shown in FIG. 1, power split mechanism 4 is constituted by a single pinion type planetary gear mechanism having sun gear 5, carrier 6, and ring gear 7 as rotating elements, and includes sun gear 5 corresponding to another rotating element in the present invention. The rotor of the first motor 2 is connected, the output shaft (crankshaft) of the engine 1 is connected to the carrier 6, and the ring gear 7 is an output element. An output gear 8 is attached as an output member to the ring gear 7, and the output gear 8 meshes with the counter driven gear 9. A counter drive gear 11 having a smaller diameter than the counter driven gear 9 is attached to the counter shaft 10 to which the counter driven gear 9 is attached, and the counter drive gear 11 meshes with the ring gear 13 in the differential 12. A drive torque is output from the differential 12 to the left and right drive wheels 14.

  The second motor 3 mainly functions as a driving force source for traveling, and a drive gear 15 attached to the rotor shaft meshes with the counter driven gear 9. The drive gear 15 is a gear having a smaller diameter than the counter driven gear 9, and therefore the drive gear 15 and the counter driven gear 9 constitute a reduction mechanism.

  A selectable one-way clutch (hereinafter referred to as SOWC) 17 is provided between the sun gear 5 to which the first motor 2 is connected and a casing 16 corresponding to a predetermined fixing portion in the present invention. In the released state, the SOWC 17 enables relative rotation in either the forward or reverse direction and does not transmit torque. In the engaged state, the relative rotation of only one of the forward and reverse directions is restricted (or prevented). The clutch is configured to transmit the torque in the direction and to allow the relative rotation in the opposite direction and not transmit the torque. Here, the forward rotation is rotation in the same direction as the rotation direction of the engine 1, and the reverse rotation (or negative rotation) is rotation in the direction opposite to the rotation direction of the engine 1. The specific configuration of the SOWC 17 will be described later.

  The first motor 2 and the second motor 3 are connected to a controller unit such as a power storage device or an inverter (not shown), and are electrically connected so that power can be exchanged between them. Further, an electronic control unit (ECU) 18 for controlling these power storage devices, controller unit, SOWC 17 and the like is provided. The electronic control unit 18 is mainly composed of a microcomputer, and detection signals such as the vehicle speed, the accelerator opening, the engine speed and the estimated output torque, the speeds and torques of the motors 2 and 3, and the operating state of the SOWC 17 are received. It is configured to be input as data, perform a calculation based on the data, and output a command signal for controlling each of the motors 2, 3 and SOWC 17.

  FIG. 2 is a collinear diagram of the planetary gear mechanism that constitutes the power split mechanism 4, and (a) shows a forward state in the hybrid mode (HV mode or power split mode). The carrier 6 rotates in the forward direction when 1 is in the driving state, and the ring gear 7 rotates in the forward direction by traveling forward. The SOWC 17 is in the released state, and the sun gear 5 and the first motor 2 connected thereto can rotate in either the forward or reverse direction. In the state of FIG. 2 functions as a generator while rotating forward. That is, the first motor 2 outputs torque in the negative direction (downward in FIG. 2A), thereby controlling the rotational speed of the engine 1 to a rotational speed with good fuel efficiency. The electric power generated by the first motor 2 is supplied to the second motor 3, and the second motor 3 functions as a motor to output a driving force for traveling.

  FIG. 2C shows a state in which the forward rotation of the sun gear 5 is stopped by the SOWC 17 and the vehicle is traveling forward by the driving force of the engine 1 or the driving force of the second motor 3 is applied thereto (so-called traveling). (Parallel mode). In this state, the rotational speed of the ring gear 7 becomes larger than the engine rotational speed (the rotational speed of the carrier 6), and torque is output from the ring gear 7. If the second motor 3 is operated as a motor, the driving force is added to the driving force output from the ring gear 7 and transmitted to the driving wheel 14 via the differential 12. Further, in this case, since the first motor 2 is fixed together with the sun gear 5 and energization is stopped (in an off state), fuel efficiency when traveling at a high vehicle speed is improved.

  FIG. 2B shows a transition state (transition state) for switching between the state shown in FIG. 2A and the state shown in FIG. 2C. The first motor 2 functions as a motor and the sun gear 5 is reversed. It is rotating in the direction of rotation. Therefore, no torque is applied to the SOWC 17 even when the SOWC 17 is engaged.

  FIG. 3 is a schematic diagram showing another example of the power transmission mechanism that can be the subject of the present invention. An overdrive (O / D) mechanism 19 is additionally provided in the configuration shown in FIG. In this example, the overdrive mechanism 19 is selectively locked by the SOWC 17. In the example shown here, the overdrive mechanism 19 is configured by a double pinion type planetary gear mechanism having the sun gear 20, the carrier 21, and the ring gear 22 as rotating elements. The carrier 6 in the power split mechanism 4 described above is connected to the carrier 21, so that the output torque of the engine 1 is transmitted to these carriers 6, 21. Further, the sun gear 5 in the power split mechanism 4 is connected to the sun gear 20, so that the torque of the first motor 2 is transmitted to the sun gears 5 and 20. Further, the SOWC 17 described above is arranged between the ring gear 22 and the casing 16, and the overdrive state is set by restricting (blocking) the rotation of the ring gear 22 in a predetermined direction by the SOWC 17. Therefore, the single pinion type planetary gear mechanism that constitutes the power split mechanism 4 and the double pinion type planetary gear mechanism that constitutes the overdrive mechanism 19 are obtained by connecting the respective rotating elements as described above. A so-called four-element compound planetary gear mechanism is configured, and this compound planetary gear mechanism corresponds to the differential mechanism in the present invention. The other configuration is the same as the configuration shown in FIG. 1, and therefore, the same reference numerals as those in FIG.

  FIG. 4 is a collinear diagram of the above-described compound planetary gear mechanism. FIG. 4A shows a forward state in a hybrid mode (HV mode or power split mode), and the engine 1 is in a driving state. As a result, the carrier 6 rotates in the forward direction, and the ring gear 7 rotates in the forward direction by traveling forward. The SOWC 17 is in the released state, and each sun gear 5 or the ring gear 22 and the first motor 2 that can rotate them can rotate in either the forward or reverse direction, as shown in FIG. Then, the 1st motor 2 is functioning as a generator, rotating forward. That is, the first motor 2 outputs a torque in the negative direction (downward in FIG. 4A), thereby controlling the rotational speed of the engine 1 to a rotational speed with good fuel efficiency. The electric power generated by the first motor 2 is supplied to the second motor 3, and the second motor 3 functions as a motor to output a driving force for traveling.

  FIG. 4C shows a state in which the forward rotation of the ring gear 22 is stopped by the SOWC 17 and the vehicle travels forward with the driving force of the engine 1 or the driving force of the second motor 3 is applied thereto. ing. In the overdrive mechanism 19, since the torque in the forward rotation direction is input to the carrier 21 in a state where the ring gear 22 is fixed so as not to rotate in the forward rotation direction, the sun gear 20 rotates in the reverse direction. In the power split mechanism 4, the sun gear 5 rotates in reverse with the sun gear 20 in the overdrive mechanism 19. Therefore, in the power split mechanism 4, the torque of the engine 1 is input to the carrier 6 while the sun gear 5 is rotating in the reverse direction, so the ring gear 7 that is an output element rotates at a higher rotational speed than the carrier 6 (that is, the engine 1). To do. That is, it becomes an overdrive state. If the second motor 3 is operated as a motor in this state, the driving force is added to the driving force output from the ring gear 7 and transmitted to the driving wheel 14 via the differential 12. Note that, in this overdrive state, the first motor 2 is fixed together with the ring gear 22 and is controlled to be in the off state, so that the fuel efficiency when traveling at a high vehicle speed is improved.

  FIG. 4B shows a transient state (transition state) for switching between the state shown in FIG. 4A and the state shown in FIG. 4C, and the first motor 2 functions as a motor. Thus, the sun gear 5 or the ring gear 22 is rotated in the reverse rotation direction. The rotational speed is the rotational speed at which the ring gear 22 rotates in the reverse direction. Therefore, even if the engagement control of the SOWC 17 is controlled, no torque is applied to the struts described later of the SOWC 17.

  Here, the configuration of the SOWC 17 will be described. In the power transmission mechanism targeted by the present invention, the SOWC described in Patent Document 1 described above, the SOWC described in US Patent Application Publication No. 2010/0252384, and the like can be adopted. A SOWC 17 configured as schematically shown in FIG. 6 can be employed. 5 and 6 show the engagement mechanism 23 in the SOWC 17, and the first clutch plate 24 is formed in a disc shape as a whole, and the disc shape is opposed to the first clutch plate 24. A second clutch plate 25 is arranged. One of these clutch plates 24 and 25 corresponds to the first member in the present invention, and the other clutch plate corresponds to the second member in the present invention. , 25 are held so that they can rotate relative to each other. For example, one clutch plate 24 (25) is attached to the casing 16 described above, and the other clutch plate 25 (24) is connected to the sun gear 5 shown in FIG. 1 or to the ring gear 22 shown in FIG.

  A concave portion that is long in the rotational direction is formed at a position that is shifted outward in the radial direction from the center of rotation on the front surface of the first clutch plate 24, that is, a predetermined portion on the outer peripheral side. Further, a pocket 27 which is a concave portion having substantially the same shape as the housing portion 26 is formed at the same radial position as the housing portion 26 on the surface of the second clutch plate 25 facing the first clutch plate 24. The accommodating portion 26 accommodates a plate-like engagement piece (hereinafter referred to as a strut) 28 whose cross-sectional shape is substantially equal to the shape of the accommodating portion 26. The strut 28 is disposed inside the accommodating portion 26 so as to swing around a support pin 29 provided in the center in the length direction of the first clutch plate 24 in the radial direction. The depth of the accommodating portion 26 differs with the support pin 29 as a boundary, and the upper half of the accommodating portion 26 in FIG. 5 is about the depth of the strut 28 or slightly deeper than that. The lower half of FIG. 5, which is the depth, is deeper than the thickness of the strut 28 and is configured so that the strut 28 can swing about the support pin 29.

  A spring 30 that applies an elastic force in a direction in which one end portion side of the strut 28 is pushed out from the accommodating portion 26 is disposed in a shallow portion of the accommodating portion 26. In addition, an actuator 31 that presses the other end side of the strut 28 in the direction of pushing out from the housing portion 26 is disposed in a deep portion of the housing portion 26. The actuator 31 only needs to be able to apply a pressing force to the other end of the strut 28, and a hydraulic actuator such as a hydraulic piston or an electromagnetic actuator such as a solenoid that generates thrust by electromagnetic force can be employed. . Therefore, in a state where the actuator 31 does not press the other end of the strut 28, the strut 28 is pressed by the spring 30 and protrudes from the accommodating portion 26, and the actuator 31 is opposed to the other end of the strut 28. In a state where the portion is pressed, the strut 28 rotates around the support pin 29 in the direction in which the spring 30 is compressed, and the entire strut 28 is configured to be accommodated in the accommodating portion 26. In order to relieve the pressing force by the actuator 31 or to allow the strut 28 to swing while the actuator 31 is pressing the one end of the strut 28, An appropriate elastic member such as a spring may be interposed between the two. Further, in the following description, when the actuator 31 is turned off, the actuator 31 presses the other end of the strut 28 to release the engagement mechanism 23, and when the actuator 31 is turned on, the actuator 31 moves to the other side of the strut 28. An example in which the end mechanism is released and the engagement mechanism 23 is engaged will be described.

  As described above, the pocket 27 formed in the second clutch plate 25 is a portion that is engaged with one end portion of the strut 28 protruding from the accommodating portion 26. Accordingly, the engaging mechanism 23 is configured such that the upward torque of FIG. 5 acts on the first clutch plate 24 or the second clutch plate 25 with one end of the strut 28 protruding toward the second clutch plate 25. When the downward torque in FIG. 5 acts, the strut 28 is engaged between the accommodating portion 26 and the pocket 27 to connect the clutch plates 24 and 25 so as to be integrated in the rotational direction. That is, the relative rotation of the first clutch plate 24 in the upward direction in FIG. 5 with respect to the second clutch plate 25, in other words, the relative rotation of the second clutch plate 25 in the downward direction in FIG. Is regulated. This regulated rotation direction is the normal rotation direction in the power transmission mechanism shown in FIGS. 1 and 3 described above. The state in which the forward rotation of the sun gear 5 or the ring gear 22 is restricted (or prevented) in this way is the engagement state of the engagement mechanism 23 or the SOWC 17. In this state, when torque in the reverse rotation direction (negative rotation direction) acts on one of the clutch plates 24, 25, that is, downward torque in FIG. 5 acts on the first clutch plate 24, or the second clutch plate 25 When the upward torque in FIG. 5 acts on the surface, the surface of the strut 28 is pushed by the edge portion of the opening end of the pocket 27 in the second clutch plate 25, and the strut 28 resists the elastic force of the spring 30. It is pushed into. That is, the engagement by the strut 28 is released, and the clutch plates 24 and 25 rotate relative to each other.

  When the actuator 31 presses the other end portion of the strut 28, the strut 28 compresses the spring 30 and rotates in the direction in which one end portion enters the accommodating portion 26, so that the strut 28 is inside the accommodating portion 26. Fits in. Accordingly, since there is no member connecting the clutch plates 24 and 25, the clutch plates 24 and 25 can be rotated in both forward and reverse directions. This state is the released state of the engagement mechanism 23 or the SOWC 17.

  As described above, the engaged state and the released state are switched by the operation of the actuator 31. Therefore, by detecting the operation state or the operation amount of the actuator 31, the engagement state and the released state are determined based on the detection result. Judgment can be made. A stroke sensor 32 for performing the detection is provided. The stroke sensor 32 may be a conventionally known appropriate sensor, for example, a sensor of a type that detects a stroke by an electrostatic capacity or an electric resistance that changes in accordance with an operation amount of the actuator 31 or optically detects a stroke. It may be a sensor of the type to do. Further, instead of detecting the stroke, a so-called ON / OFF sensor that outputs signals at the forward end and the backward end of the actuator 31 may be used.

  Since the SOWC 17 described above is a so-called meshing clutch, the strut 28 is interposed between the accommodating portion 26 in the first clutch plate 24 and the pocket 27 in the second clutch plate 25 in a state where the torque is transmitted through engagement. A frictional force is generated that is sandwiched and inhibits the rotation or swinging of the strut 28. Therefore, the control device according to the present invention for the power transmission mechanism is configured to execute the control described below. FIG. 7 is a flowchart for explaining the control example. The routine shown here is performed every predetermined short time when the vehicle is running with the SOWC 17 engaged or when the engine 1 is operating. Repeatedly executed. In step S1, it is determined whether or not the determination to release the SOWC 17 is established. In the hybrid vehicle having the power transmission mechanism having the configuration shown in FIG. 1, when the SOWC 17 is engaged and the forward rotation of the sun gear 5 is stopped, the second motor is applied to the driving force of the engine 1 or the driving force of the engine 1. The vehicle is running with a driving force of 3 driving force. This driving state is called a parallel mode. On the other hand, the drive state in which the SOWC 17 is released is the HV mode or the power split mode shown in FIG. 2A described above, and the substantial gear ratio is larger than that of the parallel mode. As described above, since the acceleration performance or power performance of the vehicle differs depending on each travel mode, each travel mode can be determined in advance according to the required drive amount and vehicle speed that can be expressed by the accelerator opening. Then, since the SOWC 17 is released in the HV mode and the SOWC 17 is engaged in the parallel mode, the determination of the release of the SOWC 17 can be replaced by the determination of the travel mode, or can be performed based on the determination of the travel mode. The same applies to a vehicle including the power transmission device shown in FIG. Therefore, the determination in step S1 can be made based on the required drive amount, the vehicle speed, a map prepared in advance, and the like.

  If the driving state represented by the drive request amount or the vehicle speed has not changed enough to change the driving mode, a negative determination is made in step S1. In that case, the process returns without performing any particular control. On the other hand, if the requested amount of driving increases, for example, by depressing an accelerator pedal (not shown), an affirmative determination is made in step S1. In this case, in order to switch the SOWC 17 or the above-described engagement mechanism 23 to the released state, control for causing negative differential rotation is started. That is, torque transition control is started (step S2). This torque transition control is a control for causing the motor to gradually receive the torque that the SOWC 17 has received. In the power transmission mechanism shown in FIG. 1 or 3 described above, the torque for rotating the first motor 2 in the reverse rotation direction is gradually increased, and the torque output as the motor is gradually increased after the reverse rotation starts. Control.

  The initial torque change rate at which the torque transition control is started (the amount of increase in torque per unit time) is greater than the change rate immediately before the torque of the first motor 2 approaches the target value and stops changing the torque. Enlarge. This is because the torque is rapidly changed while the rotation speed does not change in the process of gradually increasing the torque of the first motor 2. Note that the period during which the change rate is increased may be set as appropriate in design. The rate of change is set so that the rotational speed of a rotating member such as the engine 1 does not change abruptly due to so-called overshooting of the control, or a shock is not caused accordingly. I can leave.

  The torque of the first motor 2 thus changed is almost the same as the torque acting on the sun gear 5 or the ring gear 22 and the first motor 2 based on the torque output from the engine 1, that is, the reaction torque that the first motor 2 takes on. It is determined whether or not they are equal (step S3). The torque of the engine 1 can be estimated based on the throttle opening and the fuel injection amount in a gasoline engine or a diesel engine, and the torque in the positive rotation direction acting on the sun gear 5 or the ring gear 22 based on the engine torque is As shown in FIG. 2 and FIG. 4 described above, it can be obtained by geometric analysis based on the gear ratio of the planetary gear mechanism constituting the power split mechanism 4 and the overdrive mechanism 19.

  When the negative torque is determined in step S3 because the torque of the first motor 2 does not reach the engine estimated torque reaction force, the control in step S2 is continued. On the other hand, when the torque of the first motor 2 reaches the engine estimated torque reaction force and the determination in step S3 is affirmative, the torque change rate for changing the torque of the first motor 2 is set to the above step. It is made smaller than the change rate set in S2 (step S4). When the torque of the first motor 2 changes after the torque of the first motor 2 becomes substantially equal to the engine estimated torque reaction force, the rotational speed of the engine 1 starts to change. If the change is rapid, the inertial force increases, causing a sense of discomfort such as a shock. Therefore, in step S4, the torque change rate of the first motor 2 is reduced in order to avoid or suppress such a shock or uncomfortable feeling. Therefore, the torque change rate can be determined in advance by experiments, simulations, or the like so that the change in the rotational speed of the rotating member such as the engine 1 and the inertial force associated therewith do not cause a shock or uncomfortable feeling.

  As the torque of the first motor 2 further changes, the rotational speed in the positive rotation direction of the sun gear 5 or the ring gear 22 decreases, or the rotational speed in the reverse rotation direction (negative rotation direction) gradually increases. If the change is described as a change in the SOWC 17, torque acting between the clutch plates 24 and 25 that are connected to each other with the strut 28 interposed therebetween (that is, torque transmitted by the SOWC 17) gradually decreases. Eventually it becomes “0”. This state is the state in which the determination in step S3 is established, and relative rotation between the clutch plates 24 and 25 begins to occur as the torque of the first motor 2 further changes at a small change rate. The rotation direction is a direction in which the first clutch plate 24 rotates downward with respect to the second clutch plate 25 in FIG. 5, or the second clutch plate 25 is upward with respect to the first clutch plate 24 in FIG. 5. Direction to rotate in the direction. Such relative rotation is “negative differential rotation”. The state in which this negative differential rotation occurs is the state shown in the collinear diagram in FIG. 2B and the state shown in the collinear diagram in FIG. It is determined whether or not the negative differential rotation has occurred, that is, whether or not the rotational speed of the relative rotation generated in the SOWC 17 is smaller than “0” (whether or not a negative relative rotation has occurred) (step). S5).

  The SOWC 17 that stops the rotation of the sun gear 5 or the ring gear 22 described above is a clutch mechanism that enables the so-called reverse rotation (negative rotation) of the sun gear 5 or the ring gear 22 even if it is a so-called meshing clutch mechanism. The negative differential rotation can be generated, and the negative differential rotation causes no torque to be applied to the SOWC 17 or its engagement mechanism 23 (particularly the strut 28). Therefore, if a negative determination is made in step S5, the control in step S4 is continued. On the contrary, if a positive determination is made in step S5, the forward rotation restriction of the sun gear 5 or the ring gear 22 is restricted. Is determined (lock off determination), and the actuator 31 described above is turned off (Act.off) (step S6). The lock-off determination is a determination for starting or permitting control for releasing the SOWC 17 or the engagement mechanism 23, and is control for turning on a predetermined control flag, for example. More specifically, the amount of change in the rotational speed within the dead time is obtained from the rotational speed change rate of the negative differential rotation at that time and the dead time (delay time) until the actuator 31 actually turns off, The rotation speed obtained by subtracting the amount of change in the rotation speed from a target value to be described later of the negative differential rotation is set as a threshold value, and the lock-off determination is established when the rotation speed of the negative differential rotation reaches the threshold value. Further, as described above, the OFF control of the actuator 31 is a control in which the actuator 31 presses the other end of the strut 28 toward the second clutch plate 25, and therefore the strut 28 protrudes toward the second clutch plate 25. The rotational force which moves the one end part which had been moved to the accommodating part 26 side acts.

  Subsequent to the control in step S6 or in parallel with the control in step S6, control for maintaining the rotation speed of the negative differential rotation (that is, the lock-off rotation speed) at a predetermined target value is executed (step S7). ). This control is a control for ensuring that the engagement mechanism 23 is switched to the released state and other demands on the vehicle. The target value causes the engine speed to be higher than the speed at which the self-sustaining rotation can be continued, the required driving force can be obtained, the NV characteristics are not particularly deteriorated, and the strength decreases such as resonance. Not to deteriorate the consumption rate of fuel and power, to have no adverse effect on the hybrid drive system in terms of power balance, heat generation or rotation speed, etc., the rotation speed of the above-mentioned negative differential rotation changes to the positive side due to disturbance Even in such a case, it is determined in advance based on experiments or simulations in consideration of any or all of the fact that the negative rotation speed remains in a negative state. In addition, the number of revolutions at which the engine 1 can continue to rotate independently may vary depending on the temperature of the engine 1 (engine water temperature) and the state of operation of the auxiliary machinery. Also good. Further, the time for maintaining the rotation speed of the negative differential rotation at the target value is to ensure that the strut 28 escapes from the pocket 27 even when there is a disturbance factor such as a fluctuation in the rotation speed due to the fluctuation of the engine torque. (That is, a sufficient time for switching from the engaged state to the released state), and can be determined in advance by design.

  Next, it is determined whether or not the operation amount (for example, the stroke amount) of the actuator 31 has reached an operation amount that completely releases the engagement mechanism 23, that is, whether or not the stroke is completed (step S8). This can be determined based on the detection signal from the stroke sensor 32 described above. If a negative determination is made in step S8, the engagement mechanism 23 has not been switched to the released state, so the control in step S7 is continued. On the other hand, if the determination in step S8 is affirmative, the control of the power transmission mechanism is shifted to control executed with the SOWC 17 in the released state (step S9). For example, the engine 1 and the motors 2 and 3 are controlled by switching to the HV mode, and the rotational speeds of the sun gear 5 or the ring gear 22 and the first motor 2 are the vehicle speed and accelerator opening at that time, and each planetary gear mechanism described above. The target rotational speed is determined based on the gear ratio of the motor.

  FIG. 8 shows an example of changes in the negative differential rotation speed and the torque (MG torque) of the first motor 2 when the control shown in FIG. 7 is executed. When the determination is made to switch the SOWC 17 to the released state while traveling with the SOWC 17 engaged (at time t1), the torque transition control described above is started and the torque of the first motor 2 is changed at a large change rate as described above. (At time t2). When the torque of the first motor 2 becomes substantially equal to the engine estimated reaction force torque, the torque change rate of the first motor 2 is changed to a small rate (at time t3). The time point t3 can be set to a time point when a predetermined torque range centered on the engine estimated torque reaction force is determined in advance and the torque of the first motor 2 enters the torque range.

  When the torque of the first motor 2 exceeds the estimated engine reaction torque, the first motor 2 and the sun gear 5 or the ring gear 22 gradually start to rotate in the reverse rotation direction (negative rotation direction). In the SOWC 17, the clutch plates 24 and 25 start to rotate relative to each other in the direction of releasing the connection via the strut 28. When the rotational speed reaches the threshold value for the lock-off determination described above (at time t4), the actuator 31 is controlled to release the engagement mechanism 23, that is, the SOWC 17. Thereafter, when the rotational speed of the negative differential rotation reaches the above-described target value (lock-off maintaining target rotational speed), the target value is maintained.

  Since the actuator 31 continues to operate in this state, the engagement mechanism 23 gradually switches toward the released state, and as a result, it is determined based on the detection signal of the stroke sensor 32 that the operation (stroke) of the actuator 31 has been completed. Then (time t5), the control content of the power transmission mechanism is shifted to control executed with the SOWC 17 released (time t6). Specifically, control in the HV mode is started. That is, the first motor 2 and the sun gear 5 or the ring gear 22 are rotated forward, and the first motor 2 is caused to function as a generator to generate negative torque.

  As specifically described above, according to the control device of the present invention, when the torque of the first motor 2 is increased to the target value so as to cause the SOWC 17 to generate a predetermined negative differential rotation, the torque increases. Initially, the rate of change, which is the amount of increase in torque per unit time, is increased, and the rate of change is decreased at the end when the torque of the first motor 2 approaches the target value, so the torque of the first motor 2 reaches the target value. The time to reach, that is, the time required to switch the SOWC 17 from the engaged state to the released state is shortened. Moreover, since the 1st motor 2 should just output the torque of a target value at the maximum in order to open | release SOWC17, it can prevent or suppress that the 1st motor 2 consumes electric power more than necessary. . Further, since the torque of the first motor 2 changes slowly when the torque of the first motor 2 reaches the target value, it is difficult for control over-short circuit such as the torque of the first motor 2 to greatly exceed the target value. Also in this respect, unnecessary consumption of electric power can be prevented or suppressed, and the sun gear 5 and the ring gear 22 described above can be prevented or suppressed from rotating rapidly.

    DESCRIPTION OF SYMBOLS 1 ... Engine (Eng), 2 ... 1st motor (MG1), 3 ... 2nd motor (MG2), 4 ... Power split mechanism, 5 ... Sun gear, 6 ... Carrier, 7 ... Ring gear, 8 ... Output gear, DESCRIPTION OF SYMBOLS 9 ... Counter driven gear, 16 ... Casing, 17 ... Selectable one-way clutch (SOWC), 18 ... Electronic control unit (ECU), 19 ... Overdrive (O / D) mechanism, 20 ... Sun gear, 21 ... Carrier, 22 ... Ring gear, DESCRIPTION OF SYMBOLS 23 ... Engagement mechanism 24 ... 1st clutch board, 25 ... 2nd clutch board, 26 ... Storage part, 27 ... Pocket, 28 ... Engagement piece (strut), 29 ... Support pin, 30 ... Spring, 31 ... Actuator 32 ... Stroke sensor.

Claims (1)

Engagement in which the engine and the motor are coupled to a differential mechanism that generates a differential action by a plurality of rotating elements, and the relative rotation of the first member and the second member that can be rotated relative to each other is restricted in only one direction. A selectable one-way clutch having an engagement mechanism that switches between a state and a disengaged state that allows relative rotation of the first member and the second member in both the forward and reverse directions. In the control device for a vehicle power transmission mechanism provided between another rotating element different from the rotating element and the predetermined fixing portion,
When the engagement mechanism is switched from the engaged state to the released state, the torque is applied to the other rotating element in the direction opposite to the direction in which the rotation is restricted by the selectable one-way clutch. The initial increase rate at which the torque of the motor has started to increase is made larger than the increase rate at the end when the torque of the motor approaches the target value. Control device for power transmission mechanism.

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