JP2010185466A - Clutch control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clutch control device for a vehicle, capable of restraining gear noise, a damage and a transmission shock from being generated by fluctuation in the rotation speeds of driving wheels, when engaging and disengaging a dog clutch. <P>SOLUTION: This clutch control device for the vehicle includes an integrated controller 14 for shift-controlling an automatic transmission AT, in response to a vehicle condition detected by a vehicle condition detecting means, for bringing the second clutch CL2 having a dog clutch structure into a disengaged condition, under the shift of the automatic transmission AT, and for issuing a command for bringing a meshed state, after shifted, and the controller 14 executes shift limiting determination processing for limiting the shift, when changes in the rotation speeds of the right and let driving wheels LT, RT are in a preset shift limiting state, in clutch control device for the vehicle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle clutch control device including a dog clutch that separates a drive source and a transmission between a drive source and a transmission when shifting.

  Conventionally, a transmission mechanism provided between a drive source and a drive wheel, which is provided with a dog clutch that switches a connection state at the time of shifting, is known from, for example, Patent Document 1.

  This prior art includes a gear mechanism having four rotating elements by combining two sets of planetary gear mechanisms, and any one of the rotating elements is used as an input element to which torque is input from the internal combustion engine. A structure is disclosed in which any element receives a reaction torque against the torque of the input element from a generator.

JP-A-2005-155891

  When switching the engagement state of the dog clutch as described above, the clutches are engaged by matching the rotational speeds of the input side and the output side. However, if there is a rotational speed difference of a predetermined value or more (for example, about 200 rpm) between the input side and the output side, the clutch may be damaged or a shock may occur when the clutch is disengaged.

  That is, if the rotational speed difference between the input side and the output side of the dog clutch is large, the teeth of the dog clutch may collide with each other at a rapid speed, and the clutch may be damaged or a shift shock may occur. In particular, when a vehicle travels on an unstable road such as a rough road, an icy road, or a snowy road, the rotational speed of the drive wheel is likely to fluctuate. Is more likely to occur.

  The present invention has been made paying attention to the above problems, and provides a clutch control device for a vehicle that can suppress the breakage of a dog clutch and the occurrence of a shift shock due to fluctuations in the rotational speed of a drive wheel when the dog clutch is connected or disconnected. With the goal.

  To achieve the above object, a clutch control apparatus for a vehicle according to the present invention controls a shift of a transmission according to a vehicle state detected by a vehicle state detection unit, and disengages a dog clutch during a shift of the transmission. In addition, the vehicle clutch control apparatus includes a control unit that issues a command to set the meshing state after the shift is completed, and the control unit is configured to change the rotational speed of the drive wheel when the dog clutch is input and output. In the vehicle clutch control device, a shift limit determination process for limiting the shift is executed when the shift limit state is set in advance, which may cause a discrepancy between the rotation speed and the rotation speed.

  In the vehicle clutch control apparatus according to the present invention, at the time of shifting, the control means performs the shifting operation of the transmission with the dog clutch disengaged, and then outputs to the input side and driving wheels from the driving source of the dog clutch. The dog clutch is engaged after the rotational speed with the side is substantially matched.

  At this time, if the rotational speed of the drive wheels is fluctuating due to disturbance factors such as road surface conditions, it is difficult to match the rotational speeds of the dog clutch on the input side and the output side. If engaged, the clutch may be damaged.

  Therefore, in the present invention, the control means limits the shift when the change in the rotation speed of the drive wheel indicates a preset shift limit state in which the rotation speed mismatch between the input side and the output side of the dog clutch may occur. . Therefore, when the rotational speed change as described above occurs in the drive wheel, the shifting of the dog clutch is limited by limiting the shift. Therefore, the dog clutch is restricted from meshing in a state where the input side and the output side do not coincide with each other, so that the dog clutch can be prevented from being damaged or a shift shock.

1 is an overall system diagram showing an FR hybrid vehicle (an example of a vehicle) by rear wheel drive to which the clutch control device of Embodiment 1 is applied. It is the schematic which shows an example of automatic transmission AT of the hybrid vehicle to which the clutch control apparatus of Example 1 was applied. FIG. 3 is a collinear diagram of a planetary gear PG of the automatic transmission AT shown in FIG. 2. FIG. 6 is a shift characteristic diagram in an automatic transmission AT of a hybrid vehicle to which the clutch control device of Embodiment 1 is applied. It is a flowchart which shows the flow of the shift restriction | limiting determination process performed in the integrated controller 14 of the hybrid vehicle to which the clutch control apparatus of Example 1 was applied. 6 is a time chart showing an example of operation based on drive wheel speed when drive wheel slip occurs in the first embodiment. 6 is a time chart showing an example of operation based on drive wheel acceleration when drive wheel slip occurs in Example 1. FIG. 6 is a time chart showing an example of operation based on drive wheel acceleration when drive wheel slip occurs in Example 1. FIG. 6 is a time chart illustrating an operation example when torque suppression control is executed when drive wheel slip occurs in the first embodiment. It is a time chart which shows the example which act | operated based on acceleration hunting at the time of driving | running | working on the unstable road in Example 1. FIG. 6 is a time chart illustrating an operation example when a braking operation is performed in the first embodiment. It is a block diagram which shows the structure of the part which performs the shift prohibition and the shift permission determination of Example 2. 6 is a flowchart illustrating a process flow in a shift prohibiting process according to the second embodiment. It is the schematic which shows the example of application to the electric vehicle of this invention. It is the schematic which shows the example of application to the series type hybrid vehicle of this invention. It is the schematic which shows the example of application to the series parallel type hybrid vehicle of this invention. It is the schematic which shows the example of application to the series parallel type hybrid vehicle of this invention.

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

  The clutch control device according to the embodiment of the present invention includes a drive source (Eng, MG) that applies drive force to the drive wheels (LT, RT), the drive source (Eng, MG), and the drive wheels (LT, RT). A transmission (AT) that shifts the rotational speed transmitted from the drive source (Eng, MG) and transmits it to the drive wheels (LT, RT), and the transmission (AT) And the drive source (Eng, MG), a dog clutch (CL2) that can be switched between a meshing state that transmits driving force and a disconnected state that does not transmit driving force, and the driving wheels (LT, RT) The vehicle state detecting means for detecting the vehicle state including the rotation speed of the vehicle), the shift of the transmission (AT) is controlled according to the vehicle state detected by the vehicle state detecting means, and the transmission (AT) During the shifting of the dog clutch (CL2 And a control means (14) for setting the meshing state after shifting is completed, wherein the control means (14) includes the drive wheels (LT, If the change in the rotational speed of (RT) is a preset shift restriction state in which the input speed and the output speed of the dog clutch may be mismatched, a shift restriction determination process for restricting the shift is executed. 1 is a vehicle clutch control device.

  A clutch control apparatus according to Embodiment 1 of the best mode for carrying out the invention will be described with reference to FIGS.

  First, the configuration of the drive system and the control system will be described based on a schematic diagram showing a rear wheel drive hybrid vehicle (an example of a hybrid vehicle) to which the control device of the first embodiment of FIG. 1 is applied.

  As shown in FIG. 1, the drive system of the FR hybrid vehicle of Embodiment 1 includes an engine Eng and a motor generator MG as drive sources. The first clutch CL1 is provided in the middle of the drive transmission path connecting the engine Eng and the motor generator MG, and the second clutch CL2 is provided in the middle of the drive transmission path between the motor generator MG and the automatic transmission AT. Is provided. A final gear FG, a left drive wheel LT, and a right drive wheel RT are provided on the output side of the automatic transmission AT.

  The drive system of the hybrid vehicle of the first embodiment includes an electric vehicle travel mode (hereinafter referred to as “EV mode”), a hybrid vehicle travel mode (hereinafter referred to as “HEV mode”), and a semi-electric vehicle travel mode (hereinafter referred to as “EV mode”). , “Quasi-EV mode”) and the like.

  The “EV mode” is a mode in which the first clutch CL1 is disengaged and the vehicle travels only with the power of the motor generator MG.

  The “HEV mode” is a mode in which the first clutch CL1 is engaged and the vehicle travels in any of the motor assist travel mode, travel power generation mode, and engine travel mode. The “quasi-EV mode” is a mode in which the first clutch CL1 is engaged, but the engine Eng is turned off and the vehicle travels only with the power of the motor generator MG.

  The engine Eng is capable of lean combustion, and the engine torque is controlled to coincide with the command value by controlling the intake air amount by the throttle actuator, the fuel injection amount by the injector, and the ignition timing by the spark plug.

  First clutch CL1 is interposed at a position between engine Eng and motor generator MG. As the first clutch CL1, for example, a dry clutch that is normally engaged (normally closed) with an urging force of a diaphragm spring is used, and engagement / semi-engagement / release between the engine Eng and the motor generator MG is performed. If the first clutch CL1 is in the fully engaged state, the motor torque + engine torque is transmitted to the second clutch CL2. If the first clutch CL1 is in the released state, only the motor torque is transmitted to the second clutch CL2. The half-engagement / release control is performed by stroke control with respect to the hydraulic actuator.

  The motor generator MG has an AC synchronous motor structure, and performs drive torque suppression control and rotation speed control when starting and running, and recovers vehicle kinetic energy to the battery 9 by regenerative brake control during braking and deceleration. It is.

  The second clutch CL2 is a dog clutch that transmits torque by engaging the input-side member 101 on the motor generator MG side and the output-side member 102 on the automatic transmission AT side (drive wheel side) according to the hydraulic pressure (pressing force). To switch between the meshing state and the cutting state. The second clutch CL2 transmits the torque output from the motor generator MG side to the input shaft IPS to the left and right drive wheels LT, RT via the automatic transmission AT and the final gear FG.

  As shown in FIG. 2, the automatic transmission AT includes a planetary gear PG, a low clutch LC, and a high clutch HC. The planetary gear PG has an input shaft IPS coupled to the output side member 102 of the second clutch CL2, a sun gear Sg coupled to the input shaft IPS, and a carrier Ca coupled to the output shaft OTS. The ring gear Rg can be connected to and released from the housing HS by the low clutch LC, and can be connected to and released from the sun gear Sg (input shaft IPS) by the high clutch HC.

  Therefore, the automatic transmission AT used in the first embodiment can shift in two stages, that is, a low gear (low gear stage) and a hi gear (high gear stage). That is, the low gear can be formed by releasing the high clutch HC and engaging the low clutch LC. In this case, the ring gear Rg is fixed, and as shown in the collinear diagram of FIG. 3, the sun gear Sg rotates integrally with the input shaft IPS, and the carrier Ca rotates at a reduced speed integrally with the output shaft OTS.

  The Hi gear can be formed by engaging the high clutch HC and releasing the low clutch LC. In this case, the sun gear Sg, the carrier Ca, and the ring gear Rg are integrally rotated at a constant speed.

  As shown in FIG. 1, the control system of the hybrid vehicle of the first embodiment includes an inverter 8, a battery 9, an integrated controller (control means) 14, a transmission controller 15, a clutch controller 16, and an engine controller 17. The motor controller 18 and the battery controller 19 are provided. Further, the control system of the hybrid vehicle serves as a vehicle state detection means as a second clutch input rotational speed sensor 6 (= motor rotational speed sensor), a second clutch output rotational speed sensor 7, an accelerator sensor 10, and an engine rotational speed. A sensor 11, a clutch oil temperature sensor 12, a stroke position sensor 13, a vehicle speed sensor 30, a wheel speed sensor 31, a brake sensor 32, and a parking brake sensor 33 are provided.

  Inverter 8 performs DC / AC conversion and generates a drive current for motor generator MG. Battery 9 stores regenerative energy from motor generator MG via inverter 8.

  The integrated controller 14 calculates a command value such as a target drive torque from the battery state, the accelerator opening, the vehicle speed (a value synchronized with the transmission output speed), the wheel speed, and the brake state. Based on the calculation result, command values for the actuators (motor generator MG, engine Eng, first clutch CL1, second clutch CL2, automatic transmission AT) are sent to the controllers 15, 16, 17, 18, and 19. And send.

  The transmission controller 15 performs shift control so as to achieve the shift command from the integrated controller 14.

  The clutch controller 16 inputs sensor information from the second clutch input rotational speed sensor 6, the second clutch output rotational speed sensor 7, and the clutch oil temperature sensor 12, and the first clutch hydraulic pressure command value from the integrated controller 14. The solenoid valve current is controlled so as to realize the clutch hydraulic pressure (current) command value with respect to the second clutch hydraulic pressure command value.

  The engine controller 17 inputs sensor information from the engine speed sensor 11 and performs engine torque suppression control so as to achieve the engine torque command value from the integrated controller 14. The motor controller 18 controls the motor generator MG so as to achieve the motor torque command value and the motor rotation speed command value from the integrated controller 14. Further, the engine controller 17 and the motor controller 18 cooperate to execute torque suppression control that controls engine torque and motor torque to suppress wheel spin when so-called wheel spin occurs in the drive wheel during acceleration. To do.

  The battery controller 19 manages the state of charge (SOC) of the battery 9 and transmits the information to the integrated controller 14.

  The brake controller 20 controls the hydraulic pressure of the brake device 21 based on inputs from the wheel speed sensor 31 and the brake sensor 32, and performs so-called ABS control and vehicle attitude control.

  The accelerator sensor 10 is provided in an accelerator pedal operation transmission system (not shown) and detects the accelerator opening. The vehicle speed sensor 30 is provided on the output side of the automatic transmission AT and detects the vehicle speed. The wheel speed sensor 31 is provided on each of the four wheels of the vehicle, and independently detects the rotational speed of each wheel. The brake sensor 32 detects a depression stroke of a brake pedal (not shown). The parking brake sensor 33 detects that a parking brake operating lever (not shown) has been operated more than a set amount.

  Next, the shift control executed in the integrated controller 14 of the first embodiment will be briefly described. The integrated controller 14 performs a process of switching the gear stage between the low gear and the hi gear according to the shift characteristics shown in FIG. 4 based on the accelerator opening Apo and the vehicle speed Vsp. Further, the integrated controller 14 disengages the second clutch CL2 during the shift operation of the automatic transmission AT, and after the shift is completed, after matching the rotational speeds of the input side member 101 and the output side member 102, The second clutch CL2 is engaged.

  Next, in the shift control of the integrated controller 14, the flow of the shift restriction determination process, which is a feature of the present invention, will be described based on the flowchart of FIG.

  Shift restriction state determination is performed in steps S1 to S4. In the shift limit state determination, is the change in the rotational speed of the drive wheel in an unstable state that is more than a predetermined value that makes it difficult to match the rotational speeds of the input side member 101 and the output side member 102 of the second clutch CL2? If it is determined that the shift is limited, the shift is limited. In the first embodiment, in the shift restriction state determination in steps S1 to S4, it is determined whether or not the drive wheel is in a slip state, and the road surface such as a gravel road or a rough road has unevenness or a road surface friction coefficient ( Hereinafter, it is determined whether or not the vehicle is traveling on an unstable road where the friction coefficient is changed). Driving wheel slip occurs due to excessive driving torque, and also occurs when driving on unstable roads such as bad roads, gravel roads, and unpainted roads, and on low μ roads such as frozen roads and snowy roads.

  Therefore, first, in step S1, it is determined whether or not driving wheel slip has occurred. If driving wheel slip has occurred, the process proceeds to step S2, and if driving wheel slip has not occurred, the process proceeds to step S4. . In the first embodiment, the drive wheel slip determination is performed when the drive wheel speed is equal to or higher than the slip determination speed threshold Vth (for example, Vth = 3 to 5 km / h) than the driven wheel speed, or the drive wheel acceleration is If the slip determination acceleration threshold value ath (ath = 50 km / h / s) is exceeded, it is determined that the drive wheel slips.

  Here, the acceleration is calculated by differentiating the wheel speed. However, since the influence of noise of other sensors is also assumed, a value obtained by filtering the differential value of the wheel speed is used as the wheel acceleration. .

  In step S2, it is determined whether or not the driving wheel acceleration is constant. If the acceleration is constant, the process proceeds to step S10. If not, the process proceeds to step S3.

  In step S3, it is determined whether or not the current driving wheel state is a state in which the driving wheel acceleration can be made constant by the torque suppression control. If possible, the process proceeds to step S10, and if not, the step goes to step S10. Proceed to S5.

  As described above, in the first embodiment, even if the drive wheel slip determination is made, if the drive wheel acceleration is determined to be constant in step S2, the shift prohibition flag is turned OFF. That is, when the driving wheel acceleration is constant, the target rotational speed of the input side member 101 of the second clutch CL2 can be set based on the acceleration. It is possible to make the rotation speed with the member 102 coincide.

  As described above, even if the drive wheel slip determination is made, if it is determined in step S3 that the drive wheel acceleration can be controlled to be constant by the torque suppression control, the shift is permitted as in step S2. . Further, in the first embodiment, when a shift is executed as a shift permission based on the torque suppression control, the output torque after the shift is subjected to a torque gradient limit to prevent drive wheel slip after the shift. I have to.

  As described above, the torque suppression control is a control that controls the output torque of the engine Eng and the motor generator MG using the engine controller 17 and the motor controller 18 to suppress the slip of the left and right drive wheels LT, RT. However, in addition to this, the brake controller 20 may be controlled to control the brake device 21 to apply a braking force to the drive wheels. Therefore, when the torque suppression control of the motor generator MG and the engine Eng is performed, the rotation speed of the input side member 101 of the second clutch CL2 can be controlled, while the drive wheel speed is controlled by the brake device 21 Can control the rotation speed of the output side member 102 of the second clutch CL2.

  On the other hand, in step S4, which is determined as NO in step S1 and proceeds, an unstable road determination is performed. The non-stable road refers to a road surface where unevenness is continuous, such as a gravel road or a bad road, or a road surface in which a discontinuous road surface μ is unstable, such as a snow covered part or a frozen part. On such a road surface, the wheel speed becomes irregular as shown in FIG. 10, and the acceleration also increases and decreases.

  Therefore, in the first embodiment, the determination of the unstable road is made based on whether or not acceleration hunting has occurred on the wheel. If acceleration hunting has occurred, the process proceeds to step S5, where acceleration hunting has not occurred. Advances to step S8. In the acceleration hunting determination, as shown in FIG. 10, it is determined that acceleration hunting has occurred when the wheel acceleration alternately exceeds a preset acceleration hunting threshold value ± Hth.

  In step S5, shifting is prohibited and the process proceeds to step S6. As described above, the first case where the drive wheel slip occurs, the drive wheel acceleration is not constant, and the drive wheel acceleration cannot be made constant even by the torque suppression control, and the left and right drive wheels LT, RT. In either of the second case where acceleration hunting exceeding the hunting threshold occurs in any of the above, it is assumed that the drive wheel speed change is an unstable state that is greater than or equal to a predetermined value, that is, the gear change limit state. Is prohibited.

  In step S6, it is determined whether or not the current gear position of the transmission is the low gear. If it is the low gear, the process proceeds to step S7, and if it is not the low gear, one process is terminated as it is.

  In step S7, the engine and the motor generator are controlled so that the vehicle speed falls within the range of speed allowed by the low gear. For example, in the first embodiment, if the maximum vehicle speed within the allowable speed range in which the vehicle can travel with the Low gear is 100 km / h, the vehicle speed is limited to 100 km / h or less in this step S7.

  In step S8, it is determined whether the vehicle speed is equal to or greater than the braking speed threshold value Vth2 (see FIG. 11) and the brake or parking brake is in the braking operation state (ON). Is executed, one process is terminated as it is. The braking speed threshold value Vth2 is set to a speed at which wheel slip can occur during sudden braking, for example, a speed within a range of 20 to 40 km / h. In step S8, if not in the braking state, the process proceeds to step S11. In step S10 and step S11, since the driving wheel speed is stable, the shift prohibition flag is turned OFF and one process is terminated.

Next, the operation of the first embodiment will be described.
When driving wheel slip occurs during sudden acceleration or acceleration on a low μ road, the driving wheel speed is greater than the driven wheel speed by a slip determination speed threshold Vth or slip determination. When the acceleration threshold value ath is exceeded, the processing of steps S1 → S2 is performed. If it is determined that the acceleration of the driving wheel is not constant and the driving wheel acceleration cannot be controlled to be constant by the torque suppression control, the shift is prohibited based on the processing of steps S2 → S3 → S5.

  Here, FIG. 6 shows an example in which the driving wheel speed is equal to or higher than the slip determination speed threshold value Vth than the driven wheel speed, and the slip determination speed threshold value after the driving wheel speed exceeds the slip determination speed threshold value Vth. The shift prohibition flag is turned ON until it becomes less than Vth, that is, from time t51 to time t52.

  Therefore, in the state where the drive wheel slip occurs and the rotational speed of the drive wheel is unstable, the shift is not performed even if the shift request is generated. That is, at the time of shifting, the second clutch CL2 is disengaged and the low clutch LC and the high clutch HC are engaged and switched, and then the second clutch CL2 is engaged. If a drive wheel slip occurs when the second clutch CL2 is engaged, the rotational state of the output side member 102 on the sun gear Sg side of the second clutch CL2 is unstable and the rotational speed cannot be predicted. It becomes a state. In this case, it is difficult to make the rotational speed of the input side member 101 on the motor generator MG side of the second clutch CL2 coincide with the rotational speed of the output side member 102. If the second clutch CL2 having the dog clutch structure is engaged in this rotationally inconsistent state, there is a possibility that gear noise will occur, teeth may be missing, or shock may occur.

  On the other hand, in the first embodiment, the shift between the t51 and t52 where the drive wheel slip occurs is prohibited, so that in the second clutch CL2 of the dog clutch structure, the input side member 101 and the output side member 102 It is possible to prevent gear ringing, breakage, and occurrence of shocks without being meshed in a rotationally inconsistent state.

  Further, when the shift prohibition flag is set to ON, based on the processing of steps S6 → S7, when the automatic transmission AT is a low gear, a vehicle speed limiting process is performed. Therefore, it is possible to prevent the engine Eng and the motor generator MG from over-rotating even if the shift is prohibited by the low gear.

  Next, FIG. 7 shows a case where the drive wheel acceleration is equal to or greater than the slip determination acceleration threshold value ath. In this case as well, the rotation state of the drive wheel is based on the processing of steps S1 → S2 → S3. This is an unstable state in which the number of revolutions cannot be predicted, and shifting is prohibited. In this case, the shift prohibition flag can be turned ON before the drive wheel speed becomes higher than the slip determination speed threshold Vth by more than the driven wheel speed, and the response speed is higher than that determined only by the drive wheel speed. It is possible to increase.

  Therefore, when a drive wheel slip occurs and the speed of the drive wheel cannot be suppressed to a constant level by torque suppression control, the shift is not performed even if a shift request is generated. It is to be noted that, during the shift prohibiting process, the engine Eng and the motor generator MG are prevented from over-rotation by limiting the vehicle speed based on the process from step S6 to S7, as in the case of FIG.

  Next, the operation when the driving wheel acceleration is constant will be described with reference to FIG. In the first embodiment, based on the determination in step S2, even if the driving wheel speed or the driving wheel acceleration exceeds the slip determination speed threshold value Vth or the slip determination acceleration threshold value ath, if the driving wheel acceleration is constant, the speed change is performed. Set the prohibition flag to OFF.

  That is, for example, when the driving wheel acceleration is constant, such as when accelerating at a constant acceleration on a low μ road, the second clutch CL2 is engaged at the second engagement time after a predetermined time. The rotational speed of the output side member 102 of the clutch CL2 can be estimated, and based on this, the rotational speed target value of the input side member 101 can be set based on the driving wheel acceleration. In this case, it is possible to control the rotational speeds of the input side member 101 and the output side of the second clutch CL2 to coincide with each other.

  Therefore, in the example shown in FIG. 8, the driving wheel speed is equal to or higher than the slip determination speed threshold value Vth than the driven wheel speed, and the driving wheel acceleration exceeds the slip determination acceleration threshold value ath, and at time t71, The shift prohibition flag is ON. However, when the driving wheel acceleration is constant, the shift prohibition flag is turned OFF at time t72 and the shift is permitted based on the processing from step S2 to S10.

  Therefore, the gear ratio of the automatic transmission AT can be set optimally with respect to the vehicle situation, and the power performance can be improved.

  Next, FIG. 9 shows an example of changes in drive wheel acceleration when it is determined in step S3 that the drive wheel acceleration can be controlled to be constant by torque suppression control.

  In the example shown in FIG. 9, the shift prohibition flag is turned ON at time t81 when the drive wheel speed exceeds the slip determination speed threshold value Vth. Further, from this point, torque suppression control for suppressing drive wheel slip is executed. Thus, the torque command value is gradually decreased.

  Then, at a time t82 when it is determined by subsequent torque suppression control that the driving wheel speed falls below the slip determination speed threshold value Vth and the driving wheel acceleration can be made constant, the shift prohibition flag is turned OFF, and the torque Suppression control has also ended. Further, the shift is executed by turning off the shift prohibition flag, and the rotational speed control for the shift is executed at the time between T82 and t83 along with this shift. That is, a torque command is output to the motor generator MG so that the rotational speed of the input side member 101 of the second clutch CL2 matches the rotational speed of the output side member 102 on the drive wheel side.

  Further, in the first embodiment, when the shift is performed by the shift permission by performing the torque suppression control, the torque command value is limited in the inclination of the torque, and the rising of the torque is gradual. I try to prevent slipping later.

  As described above, even if drive wheel slip occurs, when the drive wheel acceleration can be stabilized by torque suppression control, the shift prohibition flag is immediately turned OFF. To improve the power performance. In addition, when the shift is permitted by the torque suppression control as described above, it is possible to gently control the rising of the torque after the shift, and to prevent the drive wheel slip from occurring after the shift.

  Next, based on FIG. 10, an explanation will be given of the operation when the vehicle travels on an unstable road such as a rough road, a gravel road, etc. where the unevenness is continuous, or a road surface where the road surface μ is unstable. When the vehicle travels on an unstable road as described above, the driving wheel speed and the driven wheel speed almost coincide with each other and no driving wheel slip occurs, but as shown in the figure, the driving wheel speed increases and decreases in small increments. At this time, in the illustrated example, the driving wheel speed does not exceed the slip determination speed threshold value Vth, and is determined as NO in step S1.

  However, on such non-stable roads, particularly gravel roads and rough roads, acceleration hunting occurs alternately between the driving wheel and the driven wheel, exceeding the hunting threshold value ± Hth as shown in the figure.

  As described above, even if drive wheel slip does not occur, when acceleration hunting occurs, the processing of steps S1 → S4 → S5 is performed, the shift prohibition flag is turned ON, and shift is prohibited. In this case as well, based on the processing from step S6 to S7, when the gear stage of the automatic transmission AT is a low gear, speed limitation is performed.

  Next, based on FIG. 11, the operation when the driver performs a brake operation with the brake pedal or the parking brake lever while the vehicle speed is traveling at a speed higher than the braking speed threshold value Vth2 will be described. As described above, when the vehicle speed is changed by the brake operation, a shift request may be generated due to the change in the vehicle speed. However, when the brake operation is performed, the driving wheel speed becomes unstable, and when a slip that is lower than the vehicle speed occurs, the rotation speed of the input side member 101 is set to the value of the output side member 102 in the second clutch CL2. It becomes difficult to match the rotation speed.

  Therefore, when the brake is operated, the shift prohibition flag is turned on and the shift is prohibited based on the processing of steps S1, S2, S8, and S9 even if drive wheel slip and acceleration hunting have not occurred.

  Therefore, the speed change is not performed when the driving wheel speed becomes unstable due to the brake operation, and the rotational speeds of the input side member 101 and the output side member 102 do not match when CL2 of the second clutch is coupled. Can be prevented.

As described above, in the clutch control device for a hybrid vehicle according to the first embodiment, the effects listed below can be obtained.
a) The integrated controller 14 prohibits the shift when the change in the rotational speed of the left and right drive wheels LT and RT is unstable. Therefore, the rotational speed change of the left and right drive wheels LT and RT becomes unstable, and the input side member 101 and the output side member 102 of the second clutch CL2 having the dog clutch structure are restricted from meshing in a state where the rotational speeds do not match. , Gear ringing, gear breakage and shock can be suppressed.

  b) The case where the drive wheel slip occurs is included as a case where the change in the rotational speed is in the shift limit state. When this driving wheel slip occurs, it is difficult to predict the driving wheel rotation speed, and it is difficult to match the rotation speeds of the input side member 101 and the output side member 102 in the second clutch CL2. Therefore, in the second clutch CL2, it is possible to easily determine a state in which it is difficult to make the input / output side rotations coincide with each other using the existing sensor (wheel speed sensor 31).

  c) As the case where the change in the rotational speed is in the speed limit state, the unstable road surface running condition such as a bad road and a low μ road is included. When traveling on such an unstable road surface, it is difficult to predict the rotational speed of the drive wheels, and it is difficult to match the rotational speeds of the input side member 101 and the output side member 102 in the second clutch CL2. Further, when traveling on a rough road, it can be easily determined using an existing sensor (wheel speed sensor 31 or the like). Therefore, in the second clutch CL2, a state in which it is difficult to match the rotations on the input / output sides can be easily determined using the existing sensor (wheel speed sensor 31).

  d) In the state where the drive wheel slip indicating the shift limit state occurs, when the drive wheel acceleration is substantially constant, the shift limit is canceled. That is, when the driving wheel acceleration is substantially constant, the driving wheel speed can be predicted. Therefore, also in the second clutch CL2, it is possible to make the target rotational speed of the input side member 101 coincide with the rotational speed of the output side member 102 on the drive wheel side based on this prediction.

  Therefore, when the drive wheel acceleration is substantially constant in this way, the gear ratio of the automatic transmission AT is optimally set with respect to the vehicle situation and the power performance is improved by canceling the shift prohibition. Can do.

  e) In a state where a drive wheel slip indicating a shift limit state has occurred, if it is determined by torque suppression control that the drive wheel slip can be shifted to a state not corresponding to the shift limit state, the shift limit is canceled. That is, when the drive wheel slip can be suppressed by the torque suppression control, the target rotational speed of the input side member 101 can be made to coincide with the rotational speed of the output side member 102 on the driving wheel side in the second clutch CL2. is there.

  Therefore, by canceling the shift prohibition, the gear ratio of the automatic transmission AT can be set optimally with respect to the vehicle situation, and the power performance can be improved.

  f) Since the determination of the unstable road is made in the acceleration hunting state in which the acceleration of the drive wheel exceeds the preset hunting threshold, it is possible to easily determine the unstable road using the existing wheel speed sensor 31. It becomes.

  g) When the speed change is limited, if the automatic transmission AT is fixed to the low gear, when the vehicle speed is increased, the motor generator MG or the engine Eng as a drive source may be over-rotated. In the first embodiment, when the automatic transmission AT is a low gear when shifting is prohibited, the occurrence of such an overspeed can be prevented by limiting the vehicle speed.

  h) During braking, the driving wheel speed may be significantly lower than the vehicle body speed, which may cause driving wheel slip. Even when such driving wheel slip occurs during braking, it is difficult to match the target rotational speed of the input side member 101 with the rotational speed of the output side member 102 on the driving wheel side in the second clutch CL2. There is a case.

  Therefore, in the first embodiment, gear shifting is prohibited at the time of braking by foot pedal operation and parking brake lever operation (not shown), and shifting is performed at the time of braking. Etc. can be suppressed.

  i) If the driving wheel acceleration can be stabilized by torque suppression control even if driving wheel slip occurs, the shift prohibition flag is immediately turned OFF. It can be executed to improve the power performance. In addition, when the shift is permitted by the torque suppression control as described above, it is possible to gently control the rising of the torque after the shift, and to prevent the drive wheel slip from occurring after the shift.

(Other examples)
Other embodiments will be described below. Since these other embodiments are modifications of the first embodiment, only the differences will be described, and the configuration common to the first embodiment or the other embodiments will be described. The description is omitted by giving a common reference numeral.

  The second embodiment is a modification of the first embodiment. Based on the change in the rotational speed of the drive wheel, even if the shift prohibition flag in step S10 and step S11 is turned on, the input / output rotational difference in the second clutch CL2 is This is an example in which a shift prohibition mitigation process for relaxing shift prohibition is performed if it is within the allowable range. In the second embodiment, it is possible to improve the power performance by the shift by performing the shift prohibition mitigation process in this way.

The configuration will be described below.
As shown in FIG. 12, the second embodiment includes a fastening time calculation unit 201, a tolerance rotational acceleration calculation unit 202, and a shift permission determination unit 203.

The engagement time calculation unit 201 calculates the engagement time Tc, which is the time required from when the second clutch CL2 is engaged, to the actual engagement, using the following equation (1), the control sampling time, the electrical clutch response delay Calculate based on time and mechanical clutch response delay time.
Fastening time Tc
= Control sampling time + electrical delay time + mechanical response delay time (1)
Since the mechanical response delay time varies depending on the temperature or the like, the fastening time Tc is calculated using a map with the temperature as an input.

The allowable rotational acceleration calculation unit 202 is based on the engagement time Tc obtained by the engagement time calculation unit and the allowable rotation (e.g., 200 rpm) allowed when the second clutch CL2 is set in advance. The allowable rotational acceleration of the drive wheel capable of engaging the second clutch CL2 is calculated. The allowable rotational acceleration is calculated by the following equation (2).
Tolerance rotation acceleration = (Clutch tolerance rotation) / engagement time Tc (2)
The shift permission determining unit 203 compares the allowable rotational acceleration calculated by the allowable rotational acceleration calculating unit 202 with the differential rotational acceleration between the actual input side member 101 and the output side member 102 of the second clutch CL2, and actually If the drive wheel acceleration is less than the tolerance rotational acceleration, the gear shift is permitted. That is, the shift permission determination unit 203 inputs the input side rotation speed (motor rotation speed) and the output side rotation speed (drive wheel speed) of the second clutch CL2, and calculates the differential rotation acceleration.

  The allowable rotational acceleration calculated by the allowable rotational acceleration calculating unit 202 is, for example, when the engagement time Tc of the second clutch CL2 is 50 ms and the allowable rotational speed is ± 200 rpm, the allowable rotational acceleration is 200 rpm / 50 ms. Become. Thus, if the actual differential rotational acceleration of the second clutch CL2 is within 200 rpm / 50 ms, the shift is permitted, and if it is 200 rpm / 50 ms or more, the shift is prohibited.

  That is, the flowchart of FIG. 13 shows the process of the second embodiment, which is a modification of the processes of steps S10 and S11 of the first embodiment. In step S201, the actual differential rotational acceleration of the second clutch CL2 is allowed. If it is greater than the differential rotational acceleration (= clutch allowable rotational / engagement time), the process proceeds to step S202 to prohibit the shift, but if it is equal to or smaller than the allowable rotational acceleration, the process proceeds to step S203 to allow the shift. Since other processes are the same as those in the first embodiment, description thereof is omitted.

(Effect of Example 2)
As described above, in the second embodiment, even if the change in the rotational speed of the left and right drive wheels LT and RT is in a state in which shifting is prohibited, the actual differential rotational acceleration in the dog clutch type second clutch CL2 is the allowable rotational speed. If it is within the acceleration, the shift prohibition is canceled.

  Therefore, by prohibiting the shift based on the rotational speed change of the left and right drive wheels LT, RT, while suppressing the occurrence of gear ringing, breakage, shock, etc., the relaxation of the shift prohibition determination makes the shift on an unstable road such as a rough road. It is possible to improve the power performance by shifting.

  As mentioned above, although the clutch control apparatus of this invention has been demonstrated based on embodiment and Example 1, 2, a concrete structure is not restricted to these Examples, Each claim of a claim Design changes and additions are permitted without departing from the spirit of the invention according to the paragraph.

  For example, in the first and second embodiments, the drive source is provided with the engine Eng and the motor generator MG. However, the present invention is not limited to this, and as shown in FIG. It can also be applied to an electric vehicle equipped only with MG.

  In the first and second embodiments, as a hybrid vehicle, a so-called parallel type that can transmit the driving forces of both the engine Eng and the motor generator MG to the driving wheels is shown, but only the driving force of the motor MO is driven to the driving wheels. The engine Eng can also be applied to a so-called series type engine as shown in FIG. 15 used for power generation by the generator GE.

  Alternatively, it can also be applied to a series-parallel type as shown in FIGS. In FIGS. 16 and 17, PG represents a planetary gear. 14 to 17, the dog clutch is built in the automatic transmission AT and is provided between the drive source and the input shaft IPS of the automatic transmission AT, as in the first and second embodiments. To do.

  Further, in the first and second embodiments, a two-stage stepped transmission is shown in which the transmission is a low gear as a low speed gear, and a Hi gear as a high speed gear stage. Not limited to this, there may be three or more stages. In this case, the low speed gear stage is not limited to the first speed, but may be a gear stage that is relatively lower than the high speed gear stage. Similarly, the high-speed gear stage is not limited to the highest gear, and may be a gear stage that is relatively higher than the low-speed gear stage.

  In the first and second embodiments, the means for detecting the acceleration hunting of the wheel speed is shown as the means for detecting the traveling on the unstable road. However, the present invention is not limited to this, and the acceleration sensor, the in-vehicle camera, the external information Other means such as those detected from signals from communication devices may be used.

  Further, in the first and second embodiments, even when the change in the rotational speed of the drive wheel is in the speed limit state, when the predetermined condition is satisfied, the speed change is permitted without prohibiting the speed change. Instead of setting such permission conditions, the shift may be completely prohibited in the shift limit state.

  In the first and second embodiments, the second clutch CL2 is shown as the dog clutch, but the dog clutch is not limited to this. For example, the present invention can be applied to the low clutch LC and the high clutch HC shown in the first and second embodiments.

  Although the example applied to FR hybrid vehicle was shown in Example 1, 2, the control apparatus of this invention is applicable also to FF hybrid vehicle, an electric vehicle, and a fuel cell vehicle, for example. In short, any vehicle having a dog clutch can be applied.

6 Second clutch input rotation speed sensor (vehicle state detection means)
7 Second clutch output rotational speed sensor (vehicle state detection means)
10 Accelerator sensor (vehicle state detection means)
11 Engine speed sensor (vehicle state detection means)
12 Clutch oil temperature sensor (vehicle state detection means)
13 Stroke position sensor (vehicle state detection means)
14 Integrated controller (control means)
22 Brake sensor (vehicle state detection means)
23 Parking brake sensor (vehicle state detection means)
30 Vehicle speed sensor (vehicle state detection means)
31 Wheel speed sensor (vehicle state detection means)
32 Brake sensor (vehicle state detection means)
33 Parking brake sensor (vehicle state detection means)
101 Input side member 102 Output side member AT Automatic transmission ath Slip determination acceleration threshold value CL2 Second clutch (dog clutch)
Eng engine (drive source)
LT Left drive wheel RT Right drive wheel MG Motor generator (drive source)
MO motor (drive source)
Vth slip judgment speed threshold

Claims (9)

A drive source for applying drive force to the drive wheels;
A transmission that is interposed between the drive source and the drive wheel and that shifts the rotational speed transmitted from the drive source and transmits the speed to the drive wheel;
A dog clutch provided between the transmission and the drive source and capable of switching between a meshing state for transmitting a driving force and a disconnected state for not transmitting the driving force;
Vehicle state detection means for detecting a vehicle state including the rotational speed of the drive wheel;
The shift of the transmission is controlled according to the vehicle state detected by the vehicle state detection means, and the dog clutch is in the disengaged state during the shift of the transmission, and after the shift is completed, Control means to
A clutch control device for a vehicle comprising:
The control means determines a shift restriction that restricts a shift when the change in the rotational speed of the drive wheel is a preset shift restriction state in which a rotational speed mismatch between the input side and the output side of the dog clutch may occur. A vehicle clutch control device that performs processing.   2. The vehicle clutch control device according to claim 1, wherein the shift restriction determination process includes a state in which drive wheel slip occurs as the rotation speed change indicating the shift restriction state.   3. The shift restriction determination process according to claim 1, wherein the rotational speed change indicating the shift restriction state includes an unstable road running state with uneven road surfaces such as a bad road. Vehicle clutch control device.   4. The shift restriction determination process according to claim 1, wherein the drive restriction is canceled when the drive wheel acceleration is substantially constant in a state where the drive wheel slip indicating the shift restriction state occurs. The vehicle clutch control device according to claim 1. The control means executes torque suppression control that suppresses drive wheel slip when drive wheel slip occurs,
In the shift limitation determination process, when the drive wheel slip occurs, if it is determined by the torque suppression control that the drive wheel slip can be shifted to a state not corresponding to the shift limitation state, the shift limitation is canceled. The vehicle clutch control device according to any one of claims 2 to 4, wherein:   6. The shift determination process according to claim 3, wherein when the acceleration of the driving wheel exceeds a preset hunting threshold, it is determined that the vehicle is traveling on an unstable road. The clutch control device for a vehicle according to the item. The transmission includes a low gear stage having a relatively large gear ratio and a high gear stage having a relatively small gear ratio,
The speed limit determining process includes a speed limit process for limiting a speed within an allowable speed range at the low gear stage when the transmission is in a low gear stage when the shift is limited. The vehicle clutch control device according to any one of claims 1 to 6.   The clutch control apparatus for a vehicle according to any one of claims 1 to 7, wherein the shift restriction determination process includes a braking execution state as the shift restriction state.   In the shift restriction determination process, at the time of shift restriction determination, an engagement time required from the dog clutch engagement command to actual engagement is calculated, and based on the engagement time, the input side member and the output side member, A tolerance rotational acceleration that is a drive wheel acceleration that can be fastened within the tolerance rotation is calculated, and if the actual driving wheel acceleration is equal to or less than the tolerance rotational acceleration, a shift inhibition mitigation process that permits a shift is executed. The vehicle clutch control device according to any one of claims 1 to 8, wherein the vehicle clutch control device is characterized in that:

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