JP2015034586A - Fly wheel regeneration system and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a heat rate of a fly wheel clutch and to shorten an engagement time in a fly wheel regeneration system.SOLUTION: In a fly wheel regeneration system for regenerating kinetic energy in a fly wheel 2 by engaging a fly wheel clutch CLfw in decelerating a vehicle 100, and using the energy of the fly wheel 2 in starting or accelerating the vehicle, when a prescribed operating condition is satisfied in implementing regeneration by the fly wheel 2, the engagement of the fly wheel clutch CLfw is started after a change gear ratio of a transmission 3 is shifted up in a state of disengaging a power source clutch CL1.

Description

  The present invention relates to a flywheel regeneration technique for regenerating kinetic energy of a vehicle with a flywheel.

  In order to improve the fuel consumption and electricity consumption of a vehicle, it is effective to regenerate the kinetic energy of the vehicle when decelerating electrically or mechanically and use the regenerated energy when starting or accelerating.

  In Patent Document 1, a flywheel that can be connected / disconnected by a clutch is provided on an input shaft of a transmission, the flywheel is rotated by rotation input from a driving wheel by engaging the clutch during deceleration, and the kinetic energy of the vehicle is flywheel. The flywheel regeneration system which converts into the kinetic energy of is disclosed.

  In such a flywheel regeneration system, the regenerated kinetic energy can be stored in the flywheel by releasing the clutch, and the kinetic energy stored in the flywheel can be stored if the clutch is engaged during start-up or acceleration. Can be used to start and accelerate the vehicle.

Special table 2012-516417 gazette

  In the flywheel regeneration system configured as described above, the clutch is engaged when the flywheel is regenerated. However, if the rotational speed difference at the time of clutch engagement is large, the amount of heat generated by the clutch increases and the durability decreases. Further, when the rotational speed difference is large, the time until the engagement of the clutch is completed increases.

  Increasing the clutch capacity by increasing the number and surface area of clutch friction plates to prevent a decrease in the durability of the clutch may be considered, but in this case the weight and size of the clutch will increase and the fuel efficiency will decrease. To do.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a flywheel regeneration system that can reduce the amount of heat generated at the time of clutch engagement and shorten the engagement time when regeneration is performed by a flywheel. To do.

  According to an aspect of the present invention, a transmission that shifts rotation input from a power source of a vehicle and outputs the rotation to a drive wheel, a regenerative flywheel, and a power source and an input shaft of the transmission are provided. A power source clutch provided, and a flywheel clutch provided between the flywheel and the input shaft of the transmission, and when the vehicle decelerates, the flywheel clutch is engaged to regenerate kinetic energy in the flywheel, A flywheel regeneration system that uses flywheel energy for starting or accelerating a vehicle, and when performing regeneration by the flywheel, shifting is performed with the power source clutch released when a predetermined operating condition is satisfied. A flywheel regenerative system comprising regenerative control means for starting engagement of a flywheel clutch after upshifting the transmission ratio of the machine It is subjected.

  According to the above aspect, since the power source clutch is released and the transmission is upshifted, the flywheel clutch is engaged and the gear ratio is downshifted, so that the rotational speed difference when the flywheel clutch is engaged is reduced. The amount of heat generated by the flywheel clutch can be reduced, the time required for the flywheel clutch to be fully engaged can be shortened, and the time for regeneration by the flywheel can be increased, thus increasing energy efficiency. be able to.

It is a lineblock diagram of vehicles provided with a flywheel regeneration system of an embodiment of the present invention. It is a flowchart of the regeneration control of embodiment of this invention. It is a time chart of the regeneration control of the embodiment of the present invention. It is a time chart of the regeneration control of the embodiment of the present invention. It is a time chart of the regeneration control of the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an overall configuration of a vehicle 100 including a flywheel regeneration system according to an embodiment of the present invention.

  The vehicle 100 includes an engine 1 as a power source, a flywheel 2 that regenerates energy, a continuously variable transmission (hereinafter referred to as CVT) 3 that continuously changes the output rotation of the engine 1, and the output rotation of the CVT 3 that decelerates. A final reduction gear 4, a differential 5, left and right drive wheels 6, a hydraulic circuit 7, and a controller 8.

  An engine clutch CL1 is provided between the engine 1 and the input shaft 3in of the CVT 3. The engine clutch CL1 is a hydraulic clutch whose fastening capacity can be controlled by supplied hydraulic pressure, and the driving force of the engine 1 is transmitted to the CVT 3 when the engine clutch CL1 is brought into a fastening state.

  An oil pump 10 that is driven by the rotation of the input shaft 3in and generates hydraulic pressure is connected to the input shaft 3in of the CVT 3. The oil pump 10 is constituted by, for example, a gear pump or a vane pump. The hydraulic pressure generated by the oil pump 10 is supplied to a CVT 3, an engine clutch CL1, a starting clutch CL2, which will be described later, and the like via a hydraulic circuit 7 which will be described later.

  The flywheel 2 is further connected to the input shaft 3 in of the CVT 3 via a pair of reduction gear trains 11 and 12. The flywheel 2 is configured by accommodating a rotatable cylindrical body or a disk-shaped metal body in a container. The inside of the container is evacuated or depressurized in order to reduce the decrease in rotation (also referred to as windage) due to the influence of air resistance or the like when the metal body rotates.

  A flywheel clutch CLfw is provided between the reduction gear train 11 and the reduction gear train 12. The flywheel clutch CLfw is a hydraulic clutch whose fastening capacity can be controlled by supplied hydraulic pressure. The engagement capacity of the flywheel clutch CLfw is controlled by a hydraulic source capable of supplying hydraulic pressure regardless of the rotation of the input shaft 3in. Specifically, unlike the oil pump 10, the hydraulic pressure generated by a hydraulic pump driven by an electric motor is supplied to the flywheel clutch CLfw. The engagement capacity of the flywheel clutch CLfw may be controlled by an electric actuator instead of a hydraulic pump driven by an electric motor.

  A start clutch CL2 is provided between the CVT 3 and the final reduction gear 4 to transmit the rotation from the engine 1 or the flywheel 2 input through the CVT 3 to the final reduction gear 4 when starting. The starting clutch CL2 is a hydraulic clutch whose fastening capacity can be controlled by supplied hydraulic pressure. In this example, only the starting clutch CL2 is provided between the CVT 3 and the final reduction gear 4. However, a stepped transmission may be provided between the CVT 3 and the final reduction gear 4, and in this case The brake or clutch that realizes the first speed of the stepped transmission is the start clutch CL2. Start clutch CL2 may be provided between engine 1 and CVT3. Further, the input shaft 3in may be provided with a torque converter.

  The hydraulic circuit 7 includes a solenoid valve that operates in response to a signal from a controller 8 to be described later, and is connected to the CVT 3, the engine clutch CL1, the start clutch CL2, and the oil pump 10 through an oil passage. The hydraulic circuit 7 generates the hydraulic pressure required by the pulley of the CVT 3, the engine clutch CL 1, and the start clutch CL 2 using the hydraulic pressure generated by the oil pump 10 as a source pressure, and the generated hydraulic pressure is generated by the pulley of the CVT 3, the engine clutch CL 1 and Supply to start clutch CL2.

  The brake 14 is an electronically controlled brake in which the brake pedal 15 and the master cylinder 16 are mechanically independent. When the driver depresses the brake pedal 15, the brake actuator 17 displaces the piston of the master cylinder 16, and the driver depresses the brake pedal 15, that is, the hydraulic pressure corresponding to the required deceleration is supplied to the brake 14. Thus, a braking force corresponding to the required deceleration is generated. Although not shown, the brake 14 is also provided on the driven wheel.

  The controller 8 includes a CPU, a RAM, an input / output interface, and the like. The controller 8 detects a rotational speed sensor 21 that detects the rotational speed of the engine 1, a rotational speed sensor 22 that detects the rotational speed of the input shaft 3 in (input shaft rotational speed Nin) of the CVT 3, and a rotational speed Nfw of the flywheel 2. A rotation speed sensor 23 for detecting the vehicle speed, a vehicle speed sensor 24 for detecting the vehicle speed VSP, an accelerator position sensor 26 for detecting the opening degree APO of the accelerator pedal 25, a signal from the brake sensor 27 for detecting the driver's depressing force on the brake pedal 15, and the like. Is entered.

  The controller 8 performs various calculations based on the input signal, and controls the shift of the CVT 3, the engagement / release of each clutch CL 1, CL 2, CLfw, and the brake actuator 17. In particular, when the driver depresses the brake pedal 15 and the vehicle 100 decelerates, the controller 8 fastens the flywheel clutch CLfw and accelerates the rotation input from the drive wheels 6 by the reduction gear trains 11 and 12. The kinetic energy of the vehicle 100 is regenerated by rotating the flywheel 2 and converting the kinetic energy of the vehicle 100 into the kinetic energy of the flywheel 2.

  During regeneration, the controller 8 controls the engagement capacity of the flywheel clutch CLfw so as to obtain a braking force (regenerative braking) according to the driver's deceleration request. If the regenerative brake cannot be generated before the flywheel clutch CLfw is engaged, or if the regenerative brake alone cannot satisfy the driver's deceleration request, the controller 8 operates the brake actuator 17 to increase the braking force of the brake 14. The braking force according to the driver's deceleration request is obtained.

  The regenerated kinetic energy can be stored as the rotation of the flywheel 2 by releasing the flywheel clutch CLfw. By engaging the flywheel clutch CLfw while the kinetic energy is stored in the flywheel 2, the kinetic energy stored in the flywheel 2 is transmitted to the input shaft 3in, and the vehicle 100 starts or accelerates energy. can do.

  In particular, by appropriately selecting the mass of the flywheel 2 and the reduction gear ratios of the reduction gear trains 11 and 12, it is sufficient to start the heavy vehicle 100 with the flywheel fully rotating. Energy can be saved.

  Thus, when the vehicle 100 decelerates, the controller 8 engages the flywheel clutch CLfw, and the kinetic energy of the vehicle 100 is regenerated.

  Here, when the flywheel clutch CLfw is fastened, if the rotational speed difference between the input side and the output side of the flywheel clutch CLfw is large, the amount of heat accumulated in the flywheel clutch CLfw by being fastened. The peak value of becomes high, and there is a risk of affecting the durability. In order to avoid this, the time from the start of the engagement control of the flywheel clutch CLfw to the completion of the engagement after the rotational speed difference is eliminated is lengthened.

  This is a regenerative system in which the engagement of the flywheel clutch CLfw is started in the deceleration state and the gear ratio of the CVT 3 after the engagement of the flywheel clutch CLfw is downshifted to regenerate the kinetic energy of the vehicle. If the time until CLfw is completed is increased, it means that the time for the flywheel 2 to regenerate due to the downshift is shortened, and the kinetic energy of the vehicle 100 may not be sufficiently regenerated.

  For this reason, it is desirable that the rotational speed difference between the input side and the output side is small when the flywheel clutch CLfw is engaged.

  Therefore, the controller 8 performs regenerative control described below, and controls the engagement of the flywheel clutch CLfw by controlling the transmission ratio of the CVT 3 to reduce the rotational speed difference when the flywheel clutch CLfw is engaged.

  FIG. 2 is a flowchart showing the regeneration control executed by the controller 8 according to the embodiment of the present invention. The flowchart shown in FIG. 2 is executed in parallel with other processing in the controller 8 at a predetermined cycle (for example, every 10 ms).

  First, in S <b> 11, the controller 8 determines whether or not the vehicle is requested to decelerate and is in a state where regeneration by the flywheel 2 is performed. Whether the vehicle is required to decelerate is determined by whether the accelerator pedal 25 is not depressed by the signal from the accelerator opening sensor 26 (accelerator OFF) and the brake pedal 15 is depressed by the signal from the brake sensor 27. If it is detected that the vehicle is on (brake ON), it is determined that the vehicle is requested to decelerate, and the process proceeds to the next step S12. If the vehicle is not requested to decelerate, the process of this flowchart is temporarily terminated and the process returns to other processes.

  Next, in step S12, the controller 8 determines whether or not the current vehicle speed VSP is less than the lower limit vehicle speed VSP0.

  The lower limit vehicle speed VSP0 is the vehicle speed when the gear ratio of CVT3 corresponding to the rotational speed of the engine 1 when the accelerator opening APO is 0 is the highest state based on the shift map of CVT3 in which the coast line is set. Is the minimum value. When the accelerator is OFF, that is, in the coast state, the controller 8 controls the gear ratio of the CVT 3 based on the coast state shift map. Since there is a correlation between the rotational speed Ne of the engine 1, the vehicle speed VSP, and the gear ratio in the coast state, a lower limit vehicle speed VSP0 that is the minimum value of the vehicle speed when the gear ratio is the highest is obtained.

  When the vehicle speed is equal to or higher than the lower limit vehicle speed VSP0, the speed ratio is the highest, and the speed ratio of CVT3 cannot be upshifted any more in the control described later. In this case, the process of this flowchart is once ended and the process returns to other processes.

  Next, in step S13, the controller 8 determines whether or not the input shaft rotational speed Nin of the CVT 3 is higher than the input shaft equivalent flywheel rotational speed Nfwin that is the rotational speed of the input shaft 3in of the flywheel 2.

  The input shaft equivalent flywheel rotational speed Nfwin indicates the rotational speed of the input shaft 3in when the flywheel clutch CLfw is in the engaged state. When the flywheel clutch CLfw is in the disengaged state, the input shaft equivalent flywheel rotational speed Nfwin is calculated by dividing the flywheel rotational speed Nfw by the reduction gear ratio of the reduction gear trains 11 and 12.

  When the input shaft rotation speed Nin is equal to or smaller than the input shaft conversion flywheel rotation speed Nfwin, the rotation speed of the flywheel 2 is equal to or higher than the rotation speed obtained by deceleration of the vehicle 100, and kinetic energy cannot be further regenerated. Therefore, the process of this flowchart is once terminated and the process returns to other processes.

  When the input shaft rotation speed Nin is higher than the input shaft conversion flywheel rotation speed Nfwin, the process proceeds to the next step S14 in order to control the gear ratio to the upshift side.

  In step S14, the controller 8 upshifts the gear ratio of CVT3. Specifically, the engine clutch CL1 is released and the gear ratio of the CVT 3 is controlled to the upshift side. At this time, since the deceleration due to the effect of the engine brake is decreased by releasing the engine clutch CL1, the controller 8 increases the braking force of the brake 14 to compensate for the decrease in the deceleration.

  In step S14, when the gear ratio of CVT3 is upshifted, the controller 8 calculates a new pulley ratio (ip = ip−Δi) obtained by subtracting a predetermined value Δi from the current pulley ratio ip of CVT3. It is set as the target value for the transmission ratio of CVT3. By this process, the gear ratio is upshifted to the High side by a predetermined value Δi. Here, the upshift to the High side refers to a shift to the High side from the gear ratio corresponding to the coast line in the shift map of the CVT 3.

  Next, the process proceeds to step S15, where the controller 8 determines whether or not the gear ratio of the CVT 3 is the highest. Whether or not the gear ratio is the highest is determined by whether or not the current pulley ratio ip of the CVT 3 is larger than the pulley ratio iOD corresponding to the highest. When the gear ratio is the highest, the input shaft rotational speed Nin is the smallest due to the gear ratio of CVT3. Therefore, the rotational speed difference between the input shaft rotational speed Nin and the input shaft equivalent flywheel rotational speed Nfwin at this point in time. Is minimized. In this case, the process proceeds to step S21 to perform control for engaging the flywheel clutch CLfw.

  In step S16, the controller 8 determines whether or not the current input shaft rotational speed Nin is higher than the input shaft-converted flywheel rotational speed Nfwin.

  As a result of upshifting CVT3, when the input shaft rotational speed Nin is equal to or smaller than the input shaft converted flywheel rotational speed Nfwin, the rotational speed difference in the flywheel clutch CLfw is minimized, and the gear ratio is further upshifted. Therefore, the process proceeds to step S21. This can occur, for example, when the input shaft-converted flywheel rotational speed Nfwin before starting regeneration by the flywheel 2 is greater than zero and less than or equal to the input shaft rotational speed Nin corresponding to the coast line in the shift map of CVT3. . If the input shaft rotational speed Nin is still higher than the input shaft converted flywheel rotational speed Nfwin, the process proceeds to step S17.

  In step S17, the controller 8 determines whether or not the current input shaft rotation speed Nin is greater than a value (oil amount balance allowable rotation speed Npf) obtained by adding a predetermined value α to the oil amount balance limit rotation speed Npump. .

  The oil amount balance limit rotational speed Npump is the sum of the hydraulic pressure required for maintaining the transmission ratio and shifting of the CVT 3 and the hydraulic pressure required for the starting clutch CL2 for the discharge pressure of the oil pump 10 rotated by the input shaft 3in. This is the minimum rotational speed of the oil pump 10 necessary to ensure the necessary hydraulic balance.

  When the rotational speed of the oil pump 10 is lower than the oil amount balance limit rotational speed Npump, the discharge hydraulic pressure of the oil pump 10 is lowered, and the engagement capacity is insufficient in the CVT 3 or the starting clutch CL2, and the power can be transmitted correctly. become unable.

  In particular, during regenerative control in the present embodiment, the vehicle 100 is decelerating and the input shaft rotational speed Nin tends to decrease. In such a situation, when the flywheel clutch CLfw is engaged when the input shaft rotational speed Nin is close to the oil amount balance limit rotational speed Npump, the input shaft rotational speed Nin is reduced by the engagement and the oil amount balance limit is reached. The rotational speed may be lower than Npump. In order to prevent this, the input shaft rotation speed Nin is controlled so as not to fall below the oil amount balance allowable rotation speed Npf obtained by adding a predetermined amount α to the oil amount balance limit rotation speed Npump.

  In the process of step S17, when the current input shaft rotational speed Nin is equal to or smaller than the oil amount allowable rotational speed Npf, the process proceeds to step S21 to interrupt the upshifting of the gear ratio of CVT3 and The wheel clutch CLfw is fastened.

  If the current input shaft rotation speed Nin is greater than the oil amount balance allowable rotation speed Npf, the process returns to step S14, and the processes of steps S14 to S17 are repeated. In this repeated process, the transmission ratio of the CVT 3 is upshifted.

  By repeating these steps S14 to S17, the input shaft rotational speed Nin reaches the input shaft equivalent flywheel rotational speed Nfwin, or the input shaft rotational speed Nin reaches the oil amount until the transmission gear ratio becomes the highest. The gear ratio of the CVT 3 is changed by a predetermined value Δi until the balance allowable rotation speed Npf is reached, and the CVT 3 is upshifted.

  By changing the gear ratio step by step by a predetermined amount, the actual gear ratio of the CVT 3 is changed following this. Note that when the engine clutch CL1 is released in the CVT3 upshift, the inertia of the CVT3 (weight connected to the tip of the input shaft 3in, thrust for pinching the belt, etc.) is small. It can be made smaller than that at the time of shifting.

  In step S21, the controller 8 increases the engagement capacity of the flywheel clutch CLfw and controls the flywheel clutch CLfw to the engagement state. As a result, the rotation of the flywheel 2 rises and the kinetic energy is regenerated by the flywheel 2. At this time, since the load corresponding to the flywheel 2 is generated on the input shaft 3in due to the engagement of the flywheel clutch CLfw, the deceleration with respect to the vehicle 100 increases. Therefore, the controller 8 reduces the braking force applied to the brake 14 set in step S14 in response to the change in the variable speed.

  After the process of step S21, the process proceeds to step S22, and the controller 8 determines whether or not the input shaft rotation speed Nin is higher than the input shaft conversion flywheel rotation speed Nfwin. If the input shaft rotation speed Nin is higher than the input shaft conversion flywheel rotation speed Nfwin, the flywheel clutch CLfw is not yet engaged and is not engaged, so the process returns to step S21 and the process is repeated.

  When the input shaft rotational speed Nin becomes equal to the input shaft converted flywheel rotational speed Nfwin, the flywheel clutch CLfw is completely engaged. In this state, the rotation of the input shaft 3 in is transmitted to the flywheel 2 through the reduction gear trains 11 and 12 to regenerate kinetic energy.

  After the flywheel clutch CLfw is completely engaged, the process proceeds to step S23, and the controller 8 downshifts the transmission ratio of the CVT 3 to the Low side. By downshifting the CVT 3, the rotational speed of the input shaft 3in is increased, and the rotational speed of the flywheel 2 can be further increased.

  As described above, in the flowchart of FIG. 2, the controller 8 determines that the current vehicle speed VSP in step S12 is the lower limit vehicle speed in a predetermined operating condition (the vehicle in step S11 is requested to decelerate and regeneration is performed by the flywheel 2). If the input shaft rotational speed Nin in step S13, which is less than VSP0, is greater than the input shaft converted flywheel rotational speed Nfwin), the gear ratio of CVT3 is upshifted while the engine clutch CL1 is released. In step S21, the engagement of the flywheel clutch CLfw is started.

  By performing such control, the rotational speed difference when the flywheel clutch CLfw is engaged is reduced, so that the amount of heat generated during engagement can be suppressed and the engagement time can be shortened, and the deceleration energy of the vehicle can be reduced. More regeneration can be achieved by the flywheel 2. Even when the vehicle is not decelerating, it may be determined that the predetermined driving condition is satisfied at least when step S13 is YES.

  The regenerated kinetic energy is output from the input shaft 3in to the drive wheels 6 by setting the start clutch CL2 and the flywheel clutch CLfw to the engaged state when the vehicle starts or accelerates. As a result, the fuel consumption of the engine 1 can be reduced and the fuel consumption can be improved.

  In the flowchart of FIG. 2, the process proceeds to step S14 when the input shaft rotation speed Nin is higher than the input shaft conversion flywheel rotation speed Nfwin in step S13, but is not limited thereto. For example, instead of the process of step S13, when (input rotational speed Nin−input shaft converted flywheel rotational speed Nfwin)> predetermined value, the process may proceed to step S14. The predetermined value here is set to a rotational speed difference that does not affect the decrease in durability when the flywheel clutch CLfw is engaged.

  Further, when the determination is performed in this way, as a condition for terminating the CVT 3 upshift, in addition to the determinations of steps S15 to S17, (input shaft rotational speed Nin−input shaft converted flywheel rotational speed Nfwin)> predetermined A determination of “value” may be added, and if this determination is YES, the process may return to step S14, and if NO, the process may proceed to step S21. By adopting such a configuration, when performing regeneration of the flywheel 2, if the rotational speed difference of the flywheel clutch CLfw is a rotational speed difference that does not affect the decrease in durability, an upshift that reduces the rotational speed difference. Since the flywheel clutch CLfw is engaged without performing the above, regeneration of the flywheel 2 can be started earlier by the time required for the upshift.

  Next, the effect by performing regeneration control in this embodiment is demonstrated.

  FIG. 3 is a time chart of the regeneration control according to the embodiment of the present invention.

  The time chart shown in FIG. 3 shows, from the top, the vehicle speed VSP, the accelerator opening APO, the brake state, the transmission ratio of CVT3, the input shaft rotational speed Nin, the input shaft converted flywheel rotational speed Nfwin, the state of the engine clutch CL1, and The flywheel clutch CLfw state is shown with time on the horizontal axis.

  The example shown in FIG. 3 shows the operation of regenerative control when the vehicle is traveling at a certain vehicle speed and the accelerator is off and the brake is on.

  At timing t01, when the accelerator is OFF, that is, the accelerator opening APO is 0, and the brake is ON, that is, when the brake pedal 15 is depressed, the determination in step S11 of the flowchart shown in FIG. The process is executed.

  The controller 8 releases the engine clutch CL1 in step S14 and gradually upshifts the gear ratio of the CVT3. At this time, the controller 8 controls the brake 14 so that the deceleration according to the engine brake and the depression of the brake pedal is obtained until the flywheel clutch CLfw is controlled to be engaged after the engine clutch CL1 is released. Increase power. In FIG. 3, the state where the braking force of the brake 14 is increased is indicated by shading.

  Thereafter, at timing t02, the transmission ratio of CVT3 reaches the highest level. When the gear ratio of CVT3 reaches the highest level, the determination in step S15 in FIG. 2 is YES, and the process proceeds to step S21 in FIG. The controller 8 controls the flywheel clutch CLfw to the engaged state. At this time, the engagement capacity of the flywheel clutch CLfw is gradually increased, and the difference in rotational speed between the input shaft rotational speed Nin and the input shaft converted flywheel rotational speed Nfwin is gradually eliminated.

  When the rotational speed difference between the input shaft rotational speed Nin and the input shaft converted flywheel rotational speed Nfwin becomes substantially zero (timing t03), the flywheel clutch CLfw is completely engaged.

  After the flywheel clutch CLfw is completely engaged, the controller 8 downshifts the transmission ratio of the CVT 3 to the Low side and further increases the rotational speed of the flywheel 2.

  Thus, the rotational speed difference between the input shaft converted flywheel rotational speed Nfwin and the input shaft rotational speed Nin can be reduced by setting the gear ratio of the CVT 3 to the highest level when the flywheel clutch CLfw is engaged.

  In the example shown in FIG. 3, the rotational speed difference B when the speed ratio of CVT3 is the highest is smaller than the rotational speed difference A when the speed ratio of CVT3 is not set to the highest. Thus, by reducing the rotational speed difference of the flywheel clutch CLfw, the amount of heat generated at the time of engagement can be suppressed, and the engagement time can be shortened.

  In particular, in this embodiment, when it is determined that regeneration by the flywheel 2 is to be performed (accelerator OFF and brake ON), control is performed so that the flywheel clutch CLfw is engaged after the CVT 3 is upshifted. At this time, since the engine clutch CL1 is released, the inertia of the CVT3 is small, and the CVT3 upshift can be performed faster than the normal shift, and therefore the timing of engaging the flywheel clutch CLfw is slightly delayed by the shift time of the CVT3. However, the rotational speed difference in the flywheel clutch CLfw can be reduced (from timing t01 to t02).

  As a result, the time required until the flywheel clutch CLfw is completely engaged is shortened, the time for regenerating the flywheel 2 can be increased, and the efficiency of regenerating kinetic energy can be increased.

  FIG. 4 is a time chart of another example of the regeneration control according to the embodiment of the present invention.

  The time chart shown in FIG. 4 is similar to the time chart of FIG. 3, and shows the operation of regenerative control when the accelerator is OFF and the brake is ON when the vehicle is traveling at a certain vehicle speed.

  If the accelerator is turned off and the brake is turned on at timing t11, the determination in step S11 in the flowchart shown in FIG. 2 is YES, and the processing from step S12 onward is executed.

  The controller 8 releases the engine clutch CL1 in step S14 and gradually upshifts the gear ratio of the CVT 3 to increase the braking force of the brake 14. Also in FIG. 4, as in FIG. 3, the state in which the braking force of the brake 14 is increased is indicated by shading.

  Thereafter, when the input shaft rotational speed Nin and the input shaft converted flywheel rotational speed Nfwin substantially coincide at timing t12, the determination in step S16 of FIG. 2 is YES. In this case, the process proceeds to step S21 in FIG. 2, and the controller 8 controls the flywheel clutch CLfw to the engaged state.

  At timing t12, since the rotational speed difference between the input shaft rotational speed Nin and the input shaft converted flywheel rotational speed Nfwin is substantially zero, the flywheel clutch CLfw can be immediately brought into a completely engaged state. After the flywheel clutch CLfw is completely engaged, the controller 8 changes the gear ratio of the CVT 3 to the Low side and increases the rotational speed of the flywheel 2.

  As described above, when the speed ratio of the CVT 3 is upshifted when the flywheel clutch CLfw is engaged, the rotational speed difference between the input shaft converted flywheel rotational speed Nfwin and the input shaft rotational speed Nin becomes substantially zero. Since the flywheel clutch CLfw can be completely engaged immediately, the amount of heat generated at the time of engagement can be suppressed, and the engagement time can be shortened.

  FIG. 5 is a time chart of still another example of the regeneration control according to the embodiment of the present invention.

  The time chart shown in FIG. 5 is similar to the time chart of FIG. 3, and shows the operation of regenerative control when the accelerator is OFF and the brake is ON when the vehicle is traveling at a certain vehicle speed.

  If the accelerator is turned off and the brake is turned on at timing t21, the determination in step S11 in the flowchart shown in FIG. 2 is YES, and the processing from step S12 onward is executed.

  Thereafter, when the input shaft rotation speed Nin becomes equal to or less than the oil amount allowable rotation speed Npf at the timing t22, the determination in step S17 of FIG. 2 is YES. In this case, the process proceeds to step S21 in FIG. 2, and the controller 8 controls the flywheel clutch CLfw to the engaged state.

  As a result, the engagement capacity of the flywheel clutch CLfw is gradually increased, and the rotational speed difference between the input shaft rotational speed Nin and the input shaft converted flywheel rotational speed Nfwin is gradually eliminated. The input shaft rotational speed Nin slightly decreases with this engagement, but the oil amount balance allowable rotational speed Npf is set to a value that is larger by a predetermined value α than the oil amount balance limit rotational speed Npump, and therefore the flywheel clutch CLfw Even if the input shaft rotational speed Nin is reduced by the fastening of, the oil amount balance limit rotational speed Npump will not fall below.

  Thereafter, when the rotational speed difference between the input shaft rotational speed Nin and the input shaft converted flywheel rotational speed Nfwin becomes substantially zero (timing t23), the flywheel clutch CLfw is completely engaged.

  After the flywheel clutch CLfw is completely engaged, the controller 8 changes the gear ratio of the CVT 3 to the Low side and increases the rotational speed of the flywheel 2.

  Thus, the rotational speed difference between the input shaft converted flywheel rotational speed Nfwin and the input shaft rotational speed Nin can be reduced by setting the gear ratio of the CVT 3 to the highest level when the flywheel clutch CLfw is engaged.

  In this case, the input shaft rotational speed Nin decreases when the flywheel clutch CLfw is engaged, but the oil amount balance allowable rotational speed Npf that is a trigger for engaging the flywheel clutch CLfw is the oil amount balance limit rotational speed Npump. Therefore, even if the input shaft rotational speed Nin is reduced, the oil amount balance lowering speed Npump is controlled to be lower than the oil amount balance limit rotational speed Npump.

  As a result, the amount of heat generated when the flywheel clutch CLfw is engaged can be suppressed, the engagement time can be shortened, and also when the engine clutch CL1 is released and the flywheel clutch CLfw is engaged, the transmission ratio of the CVT3 The minimum rotation speed of the oil pump 10 necessary to secure a necessary hydraulic pressure balance that is the sum of the hydraulic pressure required for maintenance and shifting and the hydraulic pressure required for the start clutch CL2 can be maintained.

  As described above, in the present embodiment, the CVT 3 as a transmission that shifts the rotation input from the engine 1 that is the power source of the vehicle 100 and outputs it to the drive wheels 6, the regenerative flywheel 2, the engine When the vehicle 100 decelerates, the engine clutch CL1 provided between 1 and the input shaft 3in of the CVT 3 and the flywheel clutch CLfw provided between the flywheel 2 and the input shaft 3in of the CVT 3 are provided. The flywheel clutch CLfw is engaged to regenerate kinetic energy to the flywheel 2, and the flywheel 2 is configured as a flywheel regeneration system that uses the rotational energy of the flywheel 2 for starting or accelerating the vehicle 100.

  In the flywheel regeneration system configured as described above, when regeneration is performed by the flywheel 2, when a predetermined operation condition is satisfied, the transmission ratio of the CVT 3 is upshifted in a state where the engine clutch CL1 is released. A controller 8 that performs regenerative control for starting the engagement of the flywheel clutch CLfw later is provided.

  In the present embodiment, when a predetermined operating condition is satisfied by such a configuration, the engine clutch CL1 is released when the flywheel clutch CLfw is engaged, and the gear ratio of the CVT 3 is upshifted. Therefore, the flywheel clutch CLfw The rotational speed difference at can be reduced. As a result, the amount of heat generated by the flywheel clutch CLfw can be reduced, the time required for the flywheel clutch CLfw to be fully engaged is shortened, the time for regenerating the flywheel 2 can be lengthened, and energy efficiency can be increased. Can be increased. This effect corresponds to claims 1 and 6.

  Further, the controller 8 determines that the rotational speed (input shaft rotational speed Nin) on the input shaft 3in side of the CVT 3 in the flywheel clutch CLfw is larger than the rotational speed on the flywheel 2 side (input shaft converted flywheel rotational speed Nfwin). Since it is determined that the predetermined operating condition is satisfied (step S13 in FIG. 2), when the heat generation is generated at the time of engagement because the rotational speed difference in the flywheel clutch CLfw is large, or when it takes time to complete engagement, Since the CVT 3 is upshifted, it is possible to prevent a time for regenerating the flywheel 2 from being shortened by performing an unnecessary upshift. This effect corresponds to claim 2.

  Further, since the controller 8 upshifts the CVT 3 until the difference in rotational speed when the flywheel clutch CLfw is engaged becomes substantially zero, the flywheel clutch CLfw can be completely engaged immediately. The amount of heat generated can be suppressed, and the fastening time can be shortened. This effect corresponds to the third aspect.

  The controller 8 includes an oil pump 10 that is coupled to the input shaft 3in of the CVT 3 and generates hydraulic pressure. The controller 8 has a minimum rotational speed (oil amount balance limit rotational speed Npump) in which the rotational speed of the input shaft 3in is determined from the necessary hydraulic pressure balance. The CVT3 upshift is controlled so as not to fall below. As a result, even when the engine clutch CL1 is released and the flywheel clutch CLfw is engaged, the necessary hydraulic pressure balance that is the sum of the hydraulic pressure required for maintaining the gear ratio of the CVT 3 and shifting, and the hydraulic pressure required for the start clutch CL2. The minimum rotation speed of the oil pump 10 necessary for ensuring the above can be maintained. This effect corresponds to claim 4.

  In addition, a brake 14 for braking the drive wheel 6 of the vehicle 100 is provided, and the controller 8 controls the braking force of the brake 14 to set the deceleration required for the vehicle when the engine clutch CL1 is released. To do. By configuring in this way, it is possible to achieve the deceleration intended by the driver by increasing the braking force of the brake 14 instead of the engine brake that is lost when the engine clutch CL1 is released. This effect corresponds to the fifth aspect.

  The embodiment of the present invention has been described above, but the above embodiment is merely a part of an application example of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

  For example, in the above embodiment, the vehicle 100 includes only the engine 1 as a power source. However, the vehicle 100 may include the engine 1 and a motor as power sources, or may include only a motor instead of the engine 1. Good.

  Although vehicle 100 includes CVT 3 as a transmission, the type of transmission is not limited thereto, and may include a stepped transmission instead of CVT 3. In this case, in the flowchart of FIG. 2, in the case of a shift stage that is not the highest shift stage, the processing after step S14 is executed, and control is performed so as to upshift every shift stage instead of Δi in step S14. Can do.

1 Engine (Power source)
2 Flywheel 3 CVT (Transmission)
3in input shaft 6 driving wheel 7 hydraulic circuit 8 controller 10 oil pump 21 rotational speed sensor 22 rotational speed sensor 23 rotational speed sensor 24 vehicle speed sensor 25 accelerator opening sensor 27 brake sensor 100 vehicle CL1 engine clutch (power source clutch)
CL2 Start clutch CLfw Flywheel clutch

Claims (6)

A transmission for shifting the rotation input from the power source of the vehicle and outputting it to the drive wheels;
With flywheel,
A power source clutch provided between the power source and the input shaft of the transmission;
A flywheel clutch provided between the flywheel and the input shaft of the transmission,
While the vehicle is decelerating, the flywheel clutch is engaged to regenerate kinetic energy to the flywheel, and the flywheel energy is used for starting or accelerating the vehicle.
When performing regeneration by the flywheel, when a predetermined operating condition is satisfied, the engagement of the flywheel clutch is started after the transmission gear ratio is upshifted with the power source clutch released. Regenerative control means to perform,
A flywheel regeneration system characterized by that. The flywheel regeneration system according to claim 1,
The rotation control means determines that the predetermined operating condition is satisfied when the rotational speed on the input shaft side of the transmission is higher than the rotational speed on the flywheel side in the flywheel clutch. A flywheel regeneration system. The flywheel regeneration system according to claim 1 or 2,
The regeneration control means upshifts the transmission until the rotational speed difference when the flywheel clutch is engaged is substantially zero.
A flywheel regeneration system characterized by that. The flywheel regeneration system according to claim 1, wherein
An oil pump connected to the input shaft of the transmission to generate hydraulic pressure;
The regenerative control means limits the upshift of the transmission so that the rotation speed of the input shaft does not fall below a minimum rotation speed determined from a required hydraulic balance
A flywheel regeneration system characterized by that. The flywheel regeneration system according to claim 1, wherein
A brake for braking the drive wheels of the vehicle;
The regenerative control means controls the braking force of the brake to set the deceleration required for the vehicle when the power source clutch is released, wherein the regenerative control system is a flywheel regenerative system. A transmission for shifting the rotation input from the power source of the vehicle and outputting it to the drive wheel; a flywheel for regeneration; a power source clutch provided between the power source and the input shaft of the transmission; A flywheel clutch provided between the flywheel and an input shaft of the transmission, and when the vehicle decelerates, the flywheel clutch is engaged to regenerate kinetic energy to the flywheel, A control method of a flywheel regeneration system using wheel energy for starting or accelerating the vehicle,
When performing regeneration by the flywheel,
When a predetermined operating condition is satisfied, the flywheel regeneration is started after the gear ratio of the transmission is upshifted and the engagement of the flywheel clutch is started in a state where the power source clutch is released. How to control the system.

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