JP2015150916A - Hybrid vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress clutch engagement shock and the protraction of engagement time even if the rotation speed difference between input and output shafts of a clutch is large at a time of switching an EV mode to an HEV mode.SOLUTION: In an EV mode in which an engine is stopped and a clutch CL is disengaged, it is determined whether an absolute value of a subtraction value between an estimated rotational speed of the clutch CL on a continuously variable transmission side and an actual rotational speed of the clutch CL on a driving wheel side is greater than a predetermined rotational speed difference. If it is determined that the absolute value of the subtraction value is greater than the predetermined rotational speed difference, then the engine is restarted even with an operation point in an EV area, and at least one of an engine rotational speed and a gear ratio of the continuously variable transmission is controlled so that a secondary rotational speed exceeds that of an output shaft with the clutch CL disengaged.

Description

  The present invention relates to a control device for a hybrid vehicle that is equipped with an engine, an electric motor, and a continuously variable transmission, and that can control these to drive the vehicle by driving both the engine and the electric motor.

As a conventional hybrid vehicle, for example, a vehicle described in Patent Document 1 is known.
In the hybrid vehicle described in Patent Document 1, an engine, a continuously variable transmission coupled to the output shaft of the engine, a clutch coupled to the output shaft of the continuously variable transmission, and an output shaft side of the clutch A drive wheel coupled to the drive wheel, an electric motor coupled to the drive wheel side, output control of the engine and the electric motor, control of clutch engagement / release, and shift of the continuously variable transmission according to the driving state of the vehicle Control means for performing control, and is switchable between an electric vehicle (EV) mode and a hybrid (HEV) mode. In the EV mode, the engine is stopped and the clutch is released, and power running and regeneration are performed by the electric motor.

JP 2000-199442 A

However, the conventional hybrid vehicle has the following problems because no consideration is given to the shift control of the continuously variable transmission during traveling in the EV mode.
That is, after starting the vehicle in the EV mode (engine stop and clutch release), when the operating point of the vehicle moves from the EV region to the HEV region, the stopped engine is restarted and the clutch is engaged, thereby enabling the HEV mode. Switch to
In this case, first, when starting in the EV mode, since the engine is stopped, the secondary rotational speed of the continuously variable transmission, and hence the rotational speed of the continuously variable transmission side of the clutch is zero. The rotational speed of the drive wheel side of the clutch increases as the vehicle speed increases. As a result, as the vehicle speed increases, the difference between the continuously variable transmission side rotational speed and the driving wheel side rotational speed of the clutch, that is, the rotational speed difference therebetween increases.

Such a divergence between the continuously variable transmission side rotational speed and the driving wheel side rotational speed of the clutch becomes large when the EV mode is switched to the HEV mode during high speed traveling.
For this reason, in the case where the clutch is engaged with the above-mentioned deviation, and thus the difference in the rotational speed, a large engagement shock occurs when the engagement speed of the clutch is high, resulting in discomfort to the driver. On the other hand, if the clutch engagement speed is low, the engagement shock can be alleviated, but the EV also has an unnecessarily long switching time to the HEV mode, giving the driver a sense of insecurity or discomfort. As a result, the conventional hybrid vehicle cannot satisfy both the engagement shock of the clutch and the lengthening of the engagement time at the same time when the EV mode is switched to the HEV mode.

  The present invention has been made paying attention to the above-mentioned problem, and the object of the present invention is to determine the rotational speed of the continuously variable transmission side and the rotational speed of the drive wheel side of the clutch when switching from the EV mode to the HEV mode. It is an object of the present invention to provide a control device for a hybrid vehicle that can simultaneously suppress both the clutch engagement shock and unnecessary lengthening of the clutch engagement time even when the rotational speed difference is large.

  For this purpose, the hybrid vehicle control apparatus according to the present invention provides an estimated rotational speed on the continuously variable transmission side of the clutch and an actual rotational speed on the drive wheel side during the EV mode in which the engine is stopped and the clutch is released. When it is determined whether or not the absolute value of the subtraction value is greater than the predetermined rotation speed difference, and it is determined that the absolute value of the subtraction value is greater than the predetermined rotation speed difference, the engine is operated even if the operating point is in the EV region. The engine is restarted, and at least one of the engine speed and the gear ratio of the continuously variable transmission is controlled so that the secondary speed exceeds the output shaft while the clutch is disengaged.

  In the hybrid vehicle control device of the present invention, when the EV mode is switched to the HEV mode, the difference between the rotational speed of the continuously variable transmission side of the clutch and the rotational speed of the drive wheel side is large. However, both the clutch engagement shock and the unnecessary lengthening of the clutch engagement time can be suppressed at the same time.

It is a figure which shows the relationship of each component of the hybrid vehicle carrying the control apparatus of Example 1 which concerns on this invention. (a) is a figure which shows the structure of the continuously variable transmission mounted in the hybrid vehicle of FIG. 1, (b) is a figure which shows the action | operation table | surface of the fastening element. 1 is a diagram showing a region map of each travel mode in the hybrid vehicle. It is a figure which shows the flowchart of the switching control from EV mode performed in the hybrid vehicle of FIG. 1 to HEV mode. It is a figure which shows the time chart in an example of the control performed in FIG.

  Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.

  FIG. 1 is a schematic system diagram showing a drive system and an overall control system of a hybrid vehicle on which the control device of Embodiment 1 is mounted. The hybrid vehicle of FIG. 1 is mounted with an engine (internal combustion engine) 1 and an electric motor 2 as power sources, and the engine 1 is started by a starter motor 3. The engine 1 is drive-coupled to the drive wheels 5 through a V-belt type continuously variable transmission 4 or the like so as to be appropriately separable.

  The variator VR of the continuously variable transmission (CVT) 4 is a V-belt type continuously variable motor comprising a primary pulley 6, a secondary pulley 7, and a V-belt 8 (endless flexible member) spanned between these pulleys 6 and 7. A transmission mechanism. The V belt 8 employs a configuration in which a plurality of elements are bundled by an endless belt, but may be a chain type or the like, and is not particularly limited. The primary pulley 6 is coupled to the crankshaft of the engine 1 via the torque converter T / C, and the secondary pulley 7 is coupled to the drive wheel 5 via the clutch CL and the final gear set 9 in order.

  In this embodiment, elements (such as a clutch and a brake) that connect and disconnect the power transmission path are collectively referred to as a clutch. FIG. 1 conceptually shows a power transmission path. As shown in FIG. 2, a high clutch H / C, a reverse brake R / B, and a low brake L / B provided in an auxiliary transmission 31 described later. Are collectively referred to as clutch CL. When the clutch CL is in the engaged state, the power from the engine 1 is input to the primary pulley 6 through the torque converter T / C, and then sequentially passes through the V belt 8, the secondary pulley 7, the clutch CL, and the final gear set 9 to drive wheels 5 To be used for running a hybrid vehicle.

  While the engine power is being transmitted, the pulley V groove width of the primary pulley 6 is reduced while the pulley V groove width of the secondary pulley 7 is increased, so that the winding arc diameter of the V belt 8 and the primary pulley 6 is increased, and at the same time the secondary pulley 7 Decrease the diameter of the winding arc with pulley 7. As a result, the variator VR upshifts to the high pulley ratio (high gear ratio). When the upshift to the High side gear ratio is performed to the limit, the gear ratio is set to the maximum gear ratio.

  Conversely, the pulley V groove width of the primary pulley 6 is increased while the pulley V groove width of the secondary pulley 7 is decreased, so that the winding arc diameter between the V belt 8 and the primary pulley 6 is reduced and at the same time the secondary pulley 7 Increase the winding arc diameter. Thereby, the variator VR performs a downshift to the low pulley ratio (low gear ratio). When downshifting to the low side gear ratio is performed to the limit, the gear shift is set to the minimum gear ratio.

  The variator VR has a primary rotational speed sensor 6a for detecting the rotational speed of the primary pulley 6 and a secondary rotational speed sensor 7a for detecting the rotational speed of the secondary pulley 7, and the rotational speed detected by these both rotational speed sensors. The actual gear ratio is calculated based on the above, and hydraulic control of each pulley is performed so that the actual gear ratio becomes the target gear ratio.

The electric motor 2 is always coupled to the drive wheel 5 via the reduction gear set 11 and the final gear set 11, and the electric motor 2 is driven via the inverter 13 by the power of the battery 12.
The inverter 13 converts the DC power of the battery 12 into AC power and supplies it to the electric motor 2, and controls the driving force and the rotation direction of the electric motor 2 by adjusting the power supplied to the electric motor 2.

  The electric motor 2 functions as a generator in addition to the motor drive described above, and is also used for regenerative braking. During this regenerative braking, the inverter 13 applies a power generation load corresponding to the regenerative braking force to the electric motor 2 so that the electric motor 2 acts as a generator, and the generated power of the electric motor 2 is stored in the battery 12.

  In the hybrid vehicle of the first embodiment, by driving the electric motor 2 with the clutch CL released and the engine 1 stopped, only the power of the electric motor 2 reaches the drive wheels 5 via the final gear set 11, The vehicle runs in the EV mode using only the electric motor 2. During this time, by releasing the clutch CL, the friction of the stopped engine 1 and the variator VR is reduced, and unnecessary power consumption during traveling in the EV mode is suppressed.

  When the engine 1 is started by the starter motor 3 and the clutch CL is engaged in the traveling state in the EV mode, the power from the engine 1 is converted to the torque converter T / C, the primary pulley 6, the V belt 8, the secondary pulley 7, The clutch CL and the final gear set 9 are sequentially passed to reach the drive wheel 5, and the hybrid vehicle travels in the HEV mode using the engine 1 and the electric motor 2.

  When the hybrid vehicle is stopped from the above running state or kept in this stopped state, the brake disk 14 that rotates together with the drive wheels 5 is clamped by the caliper 15 to be braked. The caliper 15 is connected to a master cylinder 18 that outputs a brake fluid pressure corresponding to the brake pedal depression force under a boost by a negative pressure brake booster 17 that responds to the depression force of the brake pedal 16 that the driver steps on. The brake disc 14 is braked by operating the caliper 15 by the brake fluid pressure generated by the master cylinder 18. In both the EV mode and the HEV mode, the hybrid vehicle drives the wheel 5 with a torque corresponding to a driving force command that is commanded by the driver depressing the accelerator pedal 19, and travels with a driving force that meets the driver's request. .

  The hybrid controller 21 selects the travel mode of the hybrid vehicle, the output control of the engine 1, the rotational direction control and output control of the electric motor 2, the shift control of the variator VR, the shift control of the auxiliary transmission 31, and the clutch CL. The fastening / release control and the charge / discharge control of the battery 12 are executed. At this time, the hybrid controller 21 performs these controls via the corresponding engine controller 22, motor controller 23, transmission controller 24, and battery controller 25.

  The hybrid controller 21 includes an accelerator pedal opening sensor that detects a signal from the brake switch 26, which is a normally open switch that switches from OFF to ON when the brake pedal 16 is depressed, and an accelerator pedal depression amount (accelerator pedal opening) APO. The signal from 27 is input. The hybrid controller 21 further exchanges internal information with the engine controller 22, the motor controller 23, the transmission controller 24, and the battery controller 25. The hybrid controller 21, the engine controller 22, the motor controller 23, and the transmission controller 24 correspond to the control means of the present invention.

  The engine controller 22 controls the output of the engine 1 in response to a command from the hybrid controller 21, and the motor controller 23 controls the rotational direction of the electric motor 2 via the inverter 13 in response to the command from the hybrid controller 21. Perform output control. The transmission controller 24 responds to a command from the hybrid controller 21 and uses oil from a mechanical oil pump O / P driven by an engine (or an electric oil pump EO / P driven by a pump motor) as a medium. The shift control of the variator VR (V-belt type continuously variable transmission mechanism VR), the shift control of the auxiliary transmission 31, and the engagement / release control of the clutch CL are performed. The battery controller 25 performs charge / discharge control of the battery 12 in response to a command from the hybrid controller 21.

  FIG. 2 (a) is a schematic system diagram showing the hybrid vehicle drive system and its overall control system of the first embodiment, and FIG. 2 (b) is a continuously variable transmission in the hybrid vehicle drive system of the first embodiment. 4 is an engagement logic diagram of a clutch CL (specifically, H / C, R / B, L / B) in the auxiliary transmission 31 incorporated in FIG. As shown in FIG. 2 (a), the auxiliary transmission 31 rotatably supports the composite sun gears 31s-1 and 31s-2, the inner pinion 31pin, the outer pinion 31pout, the ring gear 31r, and the pinions 31pin and 31pout. And a Ravigneaux type planetary gear set comprising the carrier 31c.

  Of the composite sun gears 31s-1 and 31s-2, the sun gear 31s-1 is coupled to the secondary pulley 7 so as to act as an input rotating member, and the sun gear 31s-2 is arranged coaxially with respect to the secondary pulley 7, but freely rotates. To get.

The inner pinion 31pin is engaged with the sun gear 31s-1, and the inner pinion 31pin and the sun gear 31s-2 are respectively engaged with the outer pinion 31pout.
The outer pinion 31pout meshes with the inner periphery of the ring gear 31r, and is coupled to the final gear set 9 so that the carrier 31c acts as an output rotating member.
The carrier 31c and the ring gear 31r can be appropriately coupled by the high clutch H / C as the clutch CL, the ring gear 31r can be appropriately fixed by the reverse brake R / B as the clutch CL, and the sun gear 31s-2 can be coupled by the clutch CL. It can be fixed as appropriate with a certain low brake L / B.

  In the auxiliary transmission 31, the high clutch H / C, the reverse brake R / B, and the low brake L / B are fastened in a combination indicated by a circle in FIG. 2 (b), and the others are shown in FIG. 2 (b). The first forward speed, the second forward speed, and the reverse speed stage can be selected by releasing as shown by the mark. When the high clutch H / C, reverse brake R / B, and low brake L / B are all released, the sub-transmission 31 is in a neutral state where no power is transmitted. When the transmission 31 is in the first forward speed selection (deceleration) state and the high clutch H / C is engaged, the auxiliary transmission 31 is in the second forward speed selection (direct connection) state and when the reverse brake R / B is engaged, The transmission 31 is in a reverse selection (reverse) state.

  The continuously variable transmission 4 in FIG. 2 (a) releases all the clutches CL (H / C, R / B, L / B) to bring the sub-transmission 31 into a neutral state. The pulley 7) and the drive wheel 5 can be disconnected.

The continuously variable transmission 4 in FIG. 2 (a) is controlled using oil from a mechanical oil pump O / P driven by an engine or an electric oil pump EO / P driven by a pump motor as a working medium. The transmission controller 24 includes a line pressure solenoid 35, a lockup solenoid 36, a primary pulley pressure solenoid 37-1, a secondary pulley pressure solenoid 37-2, a low brake pressure solenoid 38, a high clutch pressure & reverse brake pressure solenoid 39 and a switch. The control of the variator VR is controlled through the valve 41 as follows.
In addition to the signals described above with reference to FIG. 1, the transmission controller 24 receives a signal from the vehicle speed sensor 32 that detects the vehicle speed VSP and a signal from the acceleration sensor 33 that detects the vehicle acceleration / deceleration G.

  The line pressure solenoid 35 responds to a command from the transmission controller 24 and regulates the oil from the mechanical oil pump O / P to the line pressure PL corresponding to the vehicle required driving force. An electric oil pump EO / P is connected between the mechanical oil pump O / P and the line pressure solenoid 35, and pump discharge pressure is supplied in response to a command from the transmission controller 24.

  The lockup solenoid 36 responds to a lockup command from the transmission controller 24 and directs the line pressure PL to the torque converter T / C as appropriate, so that the torque converter T / C is connected between the input and output elements as required. Set to a directly connected lockup state.

  The primary pulley pressure solenoid 37-1 adjusts the line pressure PL to the primary pulley pressure in response to the VR gear ratio command from the transmission controller 24, and supplies this to the primary pulley 6 to The VR gear ratio command from the transmission controller 24 is realized by controlling the groove width and the V groove width of the secondary pulley 7 so that the VR gear ratio matches the command from the transmission controller 24.

The secondary pulley pressure solenoid 37-2 adjusts the line pressure PL to the secondary pulley pressure in response to a clamp force command from the transmission controller 24, and supplies the secondary pulley pressure to the secondary pulley 7. Clamp it so that it will not slip.
The low brake pressure solenoid 38 is engaged by supplying the line pressure PL to the low brake L / B as the low brake pressure when the transmission controller 24 issues the first speed selection command for the sub-transmission 31. The first speed selection command is realized.

  The high clutch pressure & reverse brake pressure solenoid 39 is a switch valve that uses the line pressure PL as the high clutch pressure & reverse brake pressure when the transmission controller 24 issues the second speed selection command or reverse selection command for the sub-transmission 31. Supply to 41.

  The maximum discharge capacity of the electric oil pump EO / P in Example 1 is set smaller than that of the mechanical oil pump O / P, and does not have the discharge capacity to shift the variator VR. The motor and pump of the electric oil pump EO / P are miniaturized by ensuring the discharge capacity that maintains the ratio or the discharge capacity that supplies lubricating oil.

At the time of the second speed selection command, the switch valve 41 uses the line pressure PL from the solenoid 39 as the high clutch pressure to the high clutch H / C, and by engaging this, the second speed selection command of the auxiliary transmission 31 is issued. Realize.
At the time of the reverse selection command, the switch valve 41 uses the line pressure PL from the solenoid 39 as the reverse brake pressure to the reverse brake R / B and fastens it, thereby realizing the reverse selection command of the auxiliary transmission 31.

In the hybrid vehicle configured as described above, a region map showing each region of the EV mode, HEV mode, EV mode regeneration, and HEV mode regeneration will be described with reference to FIG.
In FIG. 3, the horizontal axis represents the vehicle speed (VSP), the vertical axis represents the accelerator opening (APO), and the vertical axis represents the brake force (BRK). A vertical axis of zero indicates a state where neither the accelerator pedal nor the brake pedal is depressed. The accelerator opening APO increases as it goes upward from the zero position, and the brake force BRK increases as it goes downward from the zero position.

  In FIG. 3, when the accelerator pedal opening APO is small (for example, APO is 1/8 or less) and the vehicle speed is low in a state where the brake pedal is hardly depressed, the EV mode region is set and the vehicle speed VSP is low. When the accelerator opening APO is equal to or greater than the predetermined opening, and when the vehicle speed VSP is equal to or higher than the first predetermined speed regardless of the accelerator opening APO, the HEV mode region is set. In the HEV region, when the vehicle speed VSP is higher than the first predetermined speed, a shift between the first speed and the second speed of the sub-transmission 31 is performed according to the speed of the vehicle and the accelerator opening APO. The lines are shown as 1-2 shifts in FIG.

  On the other hand, when the brake pedal is depressed, the brake force BRK is applied to the vehicle. When the brake force BRK is smaller than the predetermined brake force and the vehicle speed is low, only the mechanical brake using only the brake disc 14 is operated. If the braking force BRK is small and the vehicle speed VSP is greater than the second predetermined vehicle speed, the EV regeneration region is used to cause the electric motor 2 to function as a generator. If the force is greater than or equal to a predetermined brake force, and the vehicle speed VSP is greater than or equal to the third vehicle speed regardless of the magnitude of the predetermined brake force, the HEV regeneration region is set. Here, when the brake force becomes equal to or greater than the predetermined brake force, the brake switch 26 is turned on, so that the above region is determined.

In FIG. 3, a plurality of arrows are described, and these show examples of switching from the EV mode to the HEV mode executed in this embodiment.
In other words, while driving in the EV mode where the accelerator pedal 19 is depressed or the accelerator pedal 19 is substantially released (opening sufficiently lower than the accelerator opening 1/8) and coasting (inertia), the power running in the HEV mode is performed. The case of transition to the state is shown.

  Here, the clutch CL is in a disengaged state while traveling in the EV mode. When switching from the EV mode to the HEV mode as described above, the clutch CL slides between the continuously variable transmission side and the drive wheel side. It is pressed and fastened, and the fastened state is maintained when traveling in the HEV mode.

  When the accelerator pedal 19 is released during traveling in the HEV mode and the vehicle shifts to coasting, or when the vehicle is braked by depressing the brake pedal 16 from the power running state in the HEV mode, regenerative braking by the electric motor 2 is performed. Energy efficiency is improved by converting the kinetic energy of the vehicle into electric power and storing it in the battery 12 (HEV regeneration state). By the way, when regenerative braking (HEV regenerative state) is performed in the HEV mode, since the clutch CL is in the engaged state, the regenerative braking energy corresponding to the reverse driving force (engine brake) of the engine 1 and the friction of the continuously variable transmission 4 is obtained. The energy regeneration efficiency is poor.

Therefore, when regenerative braking is started during traveling in the HEV mode and falls below the predetermined vehicle speed VSP1, the engine 1 and the variator VR are disconnected from the drive wheels 5 by the release of the clutch CL, and the traveling is shifted to the EV mode. As a result, the EV regeneration state is established, and friction caused by the engine 1 and the continuously variable transmission 4 is reduced, so that the amount of energy regeneration can be increased accordingly.
Note that the region map in FIG. 3 is basic and is based on the electric motor 2 and is variable on the base as described later according to the state of the continuously variable transmission 4.

  Next, the control at the time of transition from the EV mode to the HEV mode executed by the hybrid controller 21, the engine controller 22, the motor controller 23, the transmission controller 24, and the battery controller 25 is based on the flowchart shown in FIG. explain.

  In step S1, it is determined whether or not the hybrid vehicle is in a state of power running or regeneration in the EV mode. If the determination result is YES, the process proceeds to step S2, and if NO, the process returns to START.

  In step S2, the primary speed and the secondary speed are read from the primary speed sensor 6a and the secondary speed sensor 7a, and the vehicle speed VSP is read from the vehicle speed sensor 32, respectively. Then, it progresses to step S3.

  In step S3, first, the secondary rotational speed of the clutch CL is predicted. The prediction of the secondary rotational speed is calculated by calculation from the predicted rotational speed when the engine 1 is started and blown up and the speed ratio of the continuously variable transmission 4. The predicted rotational speed when the engine 1 is started and blown up is set in advance from past results, and the gear ratio of the continuously variable transmission 4 is determined by the primary rotational speed detected by the primary rotational speed sensor 6a, Based on the rotation speed of the secondary pulley 7 detected by the secondary rotation speed sensor 7a, the actual gear ratio is calculated, the hold value for fixing the shift when the engine is stopped is used, or it is obtained from the accompanying rotation of the pulley. Further, the output shaft rotational speed OutREV of the clutch CL is calculated from the vehicle speed VSP and the gear ratio of the final gear set 9 or the reduction gear set 11.

  The output shaft rotational speed OutRef is subtracted from the predicted secondary rotational speed SecREV-Est predicted as described above, and it is determined whether or not the absolute value of the subtracted value is larger than a predetermined rotational speed difference. Here, the predetermined rotational speed difference is that the engagement shock becomes excessive when the clutch CL is engaged without synchronously controlling the rotation speed of the engine 1 and the transmission ratio of the continuously variable transmission 4, or This is the limit rotational speed difference that does not cause the problem that the fastening time becomes excessively long, and is obtained in advance by experiments. If the determination result is YES, the process proceeds to step S4, and if NO, the process returns to step S1.

  In step S4, the engine 1 is restarted by rotating the starter motor 3 and injecting fuel even though the vehicle is traveling in the EV mode. Thereafter, the electric oil pump EO / P is started to supply pressure oil to the continuously variable transmission 4. Then, it progresses to step S5.

  In step S5, an actual speed ratio is calculated based on the primary speed detected by the primary speed sensor 6a and the speed of the secondary pulley 7 detected by the secondary speed sensor 7a. The actual secondary rotational speed of the clutch CL is calculated from the actual rotational speed, and the actual output shaft rotational speed is subtracted from the actual secondary rotational speed. When this subtraction value becomes larger than 0, in other words, it is determined whether or not the actual secondary rotational speed exceeds the actual output shaft rotational speed. If this determination is YES, the process proceeds to step S6, and if NO, the process proceeds to step S8.

In step S6, since it is determined that the actual secondary rotational speed has exceeded the actual output shaft rotational speed, the clutch CL is instructed and the clutch CL is engaged.
Then, it progresses to step S7.

  In step S7, the clutch CL in the slip state in step S8 is completely engaged. As a result, the vehicle is driven by power running or regeneration in the HEV mode. Then, it returns to step S1.

  In step S8, the shift control of the continuously variable transmission 4 of the clutch CL is started so that the secondary rotation speed exceeds the output shaft rotation speed, and the shift control of the continuously variable transmission 4 is executed together with the rotation speed control of the engine 1. To do. In addition, the clutch CL is made to slide toward the fastening. In this slip region, it is desirable to control the rotation of the engine 1 so as to increase linearly. Subsequently, the process returns to step S1.

An example of switching control from the EV mode to the HEV mode will be described based on the time chart shown in FIG.
In this figure, the horizontal axis represents time, and the vertical axis represents the running mode, continuously variable transmission state mode, ignition switch on / off, inhibitor switch position, brake switch on / off, accelerator pr. Dull opening APO, vehicle speed VSP, engine 1 stop / operation, electric motor 2 torque, engine speed EngREV, primary speed PriREV of continuously variable transmission, secondary speed SecREV, output shaft speed OutREV, continuously variable speed The primary hydraulic pressure P_pri and secondary hydraulic pressure P_sec of the machine 4 and the gear ratio DRatio of the continuously variable transmission 4 are respectively taken.

  Initially, both the engine 1 and the electric motor 2 are stopped, the vehicle speed is 0, and the ignition switch is turned on at time t0. When the ignition switch is turned on, the select lever of the continuously variable transmission 4 is in the P position and the brake pedal is depressed. Therefore, the inhibitor switch outputs a P signal and the brake switch outputs an ON signal. If the driver moves the select lever to the D position, which is the forward travel position in the order of P, R, N, and D, and releases the brake pedal at time t1, the electric motor 2 will drive and rotate even if the accelerator pedal is not depressed. start.

  Subsequently, when the accelerator pedal is depressed at time t2, the accelerator opening APO increases, and the torque and the rotational speed generated by the electric motor 2 increase. In the period up to now, the continuously variable transmission 4 is in the idle stop state or the coast stop state. Then, by depressing the accelerator pedal at time t2, the vehicle starts, and immediately before time t3, the vehicle speed VSP, and hence the output shaft side rotational speed OutREV of the clutch CL also increases. As a result, the rotational speed with the estimated secondary rotational speed SecREV Since the absolute value of the difference becomes larger than the predetermined rotational speed difference, the engine 1 is restarted at time t3. In addition, the electric oil pump EO / P also starts operation and begins to supply pressure oil to the continuously variable transmission 4.

At time t4, the primary pressure P_pri is supplied to the primary pulley, and the secondary pressure P_sec is supplied to the secondary pulley. At this time, the gear ratio of the continuously variable transmission 4 is kept at the lowest level. Thereafter, the engine 1 and the continuously variable transmission 4 are kept in operation by time t5. At this time, since the output torque of the electric motor 2 is constant and the engine 1 is also operating, the vehicle speed VSP gradually increases.
As a result, the primary rotational speed PriREV of the primary pulley, the secondary rotational speed SecREV of the secondary pulley, and the engine rotational speed EngREV rise. Therefore, the idle stop state of continuously variable transmission 4 ends at time t6.

After time t6, the clutch CL (here, the low brake) is supplied with the corresponding hydraulic pressure P_Low / B for a short time in order to pack back the clutch CL, and then this pressure is increased to the beginning. Take CL to slip. Shift control of the continuously variable transmission 4 is performed from time t7 while maintaining this slip state. This shift control is performed by controlling the hydraulic pressure supplied to the primary pulley and the secondary pulley. This control is also desirably performed so that the rotation of the engine 1 rises linearly.
In this way, slip control, engine 1 rotation speed control, and continuously variable transmission 4 shift control are performed until the secondary rotation speed exceeds the output shaft rotation speed. During this period, the vehicle travels in the HEV mode. Further, during this slip control, the output torque of the electric motor 2 is decreased.

At time t8 when the secondary rotation speed exceeds the output shaft rotation speed, the output torque of the electric motor 2 is set to 0, the clutch CL is completely engaged, and the drive mode of the engine 1 only is shifted.
Of the lines representing the rotational speeds of the elements shown in FIG. 5, the dotted line shows the case of the prior art that does not use the control of the present embodiment. Compared with this, in this embodiment, the engine 1 is started and the clutch CL is engaged. It can be seen that it can be accelerated.

As can be seen from the above description, in the hybrid vehicle control device of the present embodiment, during the EV mode, the estimated rotational speed on the continuously variable transmission 4 side of the clutch CL, the actual rotational speed on the drive wheel 5 side, and the subtraction value It is determined whether or not the absolute value of becomes greater than a predetermined rotational speed difference. If it is determined that the absolute value of the subtraction value is greater than the predetermined rotational speed difference, the engine 1 is restarted even if the operating point is in the EV region, and the secondary rotational speed is set to the output shaft while the clutch CL is released. At least one of the engine speed and the gear ratio of the continuously variable transmission 4 is controlled so as to exceed.
Therefore, in the hybrid vehicle control device of the present embodiment, the engagement shock of the clutch CL can be alleviated and the engagement time becomes excessive even when the mode change is performed and the speed difference becomes large. The effect that it can suppress can be acquired. As a result, the driver does not feel uncomfortable, uncomfortable or uneasy.

That is, when the clutch CL is completely engaged after eliminating the rotational speed difference, the continuously variable transmission 4 is upshifted so that the secondary rotational speed is synchronized (substantially coincident) with the output shaft rotational speed. In the case of fastening, since the rotational speed difference is large, it takes time to synchronize the rotation, and the problem that the time for switching from the EV mode to the HEV mode becomes unnecessarily long can be solved.
Moreover, the problem that the upshift time for rotation synchronization becomes unnecessarily long as the gear ratio of the continuously variable transmission 4 in the EV mode is closer to the lowest can be solved.
Further, since there is no sudden engagement or excessive slip, the durability of the clutch CL is also improved. Moreover, the lag at the time of acceleration can be obtained. Further, there is an advantage that a predetermined driving force can be secured.

  As described above, the power feeding device of the present invention has been described based on the respective embodiments configured as described above, but the present invention is not limited to these examples, and unless it departs from the gist of the present invention. Design changes and modifications are included in the present invention.

For example, during the slip control of the clutch CL, the rotation speed control of the engine 1 and the shift control of the continuously variable transmission 4 are performed simultaneously. However, the present invention is not limited to this, and only one of them is feedback controlled. Also good.
Further, instead of the secondary rotational speed sensor, the secondary rotational speed may be obtained from the rotational speed of the engine 1 and the gear ratio of the continuously variable transmission 4, or the vehicle speed sensor may be obtained from a wheel sensor. .

CL clutch
E / OP electric oil pump
VR variator
1 engine
2 Electric motor
3 Starter motor
4 Continuously variable transmission
5 Drive wheels
22 Engine controller (control means)
23 Motor controller (control means)
24 Transmission controller (control means)
26 Hybrid controller (control means)
32 Vehicle speed sensor

Claims (3)

Engine,
A continuously variable transmission coupled to the output shaft of the engine;
A clutch coupled to the output shaft of the continuously variable transmission;
A drive wheel connected to the output shaft of the clutch;
An electric motor connected to the output shaft of the clutch and capable of driving the drive wheels;
Control means for controlling start and operation of the engine, shifting of the continuously variable transmission, start and operation of the electric motor, and engagement and disengagement of the clutch according to an operating state;
In a hybrid vehicle equipped with
In the EV mode in which the engine is stopped and the clutch is disengaged, the control means has an absolute value of an estimated rotational speed on the continuously variable transmission side of the clutch, an actual rotational speed on the drive wheel side, and a subtraction value. When it is determined whether or not the difference between the predetermined rotational speeds is greater than the predetermined rotational speed difference and it is determined that the absolute value of the subtraction value is greater than the predetermined rotational speed difference, the engine is restarted even if the operating point is in the EV range. The hybrid is characterized in that at least one of the engine speed and the gear ratio of the continuously variable transmission is controlled so that the secondary speed exceeds the output shaft with the clutch released. Vehicle control device. In the hybrid vehicle control device according to claim 1,
The control apparatus for a hybrid vehicle, wherein the estimated secondary rotational speed is estimated from a preset rotational speed at startup of the engine and a gear ratio of the continuously variable transmission. In the control apparatus of the hybrid vehicle of Claim 1 or Claim 2,
The difference between the predetermined rotational speeds is the occurrence of an engagement shock exceeding a predetermined value when the clutch is engaged after a predetermined time from the switching command without performing the synchronization control, and an engagement time exceeding the predetermined value of the clutch. A hybrid vehicle control device characterized by the following:

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