JP2010112408A - Controller for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress an output level difference of a driving wheel before and after execution of fuel cut. <P>SOLUTION: The controller (an electronic controller) for the automatic transmission 10 is mounted on a vehicle wherein an engine (an internal combustion engine 50) carries out fuel cut if predetermined fuel cut execution requirements are satisfied at vehicle deceleration, and by controlling an engagement state of one selected from a plurality of torque variable engagement means (first to fourth clutches C1-C4 and first to fourth brakes B1-B4) in response to a gear position, gear change operation to the gear position is carried out. A control means is provided for controlling torque variable engagement means in disengaged states not used in the present gear position into engaged states during a period from satisfaction of the fuel cut execution requirements until starting of actual fuel cut. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an automatic transmission mounted on a vehicle in which an engine performs fuel cut when the vehicle is decelerated.

  Conventionally, an automatic transmission is mounted on a vehicle in which an engine performs fuel cut when the vehicle is decelerated, and performs a shifting operation to a desired gear stage by controlling a plurality of clutches and brakes to an engaged state. is there.

  In Patent Document 1 below, there is a technique for gradually releasing the engine brake element of the automatic transmission from the operating state when stopping the fuel cut so as not to generate a shock when the fuel cut is restored. It is disclosed.

JP 2004-28213 A

  By the way, in the engine, the output of the automatic transmission is greatly reduced after the execution of the fuel cut under the condition of the same engine speed and the speed of the engine is kept constant, thereby generating a large output step. Under such conditions, the output level difference of the engine directly becomes the output level difference of the drive wheels. For this reason, the step difference in the output of the drive wheel causes output fluctuation in the drive wheel and causes a rapid increase in the vehicle deceleration, which gives the driver a sense of incongruity.

  Accordingly, the present invention has an object to provide a control device for an automatic transmission that can improve the disadvantages of the conventional example and reduce the step of the output of the drive wheel before and after the execution of the fuel cut. To do.

  In order to achieve the above object, according to the first aspect of the present invention, if a predetermined fuel cut execution requirement is met when the vehicle decelerates, the engine is mounted on the vehicle that performs fuel cut, and the plurality of torque variable engagement means are selected. In a control device for an automatic transmission that performs a shift operation to the gear stage by controlling the selection according to the gear stage to the engaged state, the fuel cut actually starts after the fuel cut execution requirement is satisfied Control means is provided for controlling the variable torque engaging means in the released state that is not being used at the current shift stage until it is engaged.

  In the automatic transmission, load torque (loss torque) is generated by controlling the unused torque variable engagement means to the engaged state. In the vehicle, the load torque (loss torque) is transmitted to the drive wheels and becomes a load on the drive wheels, so that the output of the drive wheels is reduced. Therefore, the control device for the automatic transmission according to claim 1 puts the unused torque variable engagement means into the engaged state between the time when the fuel cut execution requirement is satisfied and the time when the fuel cut is actually started. Since the output of the drive wheel can be reduced in advance before execution of the fuel cut, the output step difference of the drive wheel before and after execution of the fuel cut can be reduced.

  In order to achieve the above object, according to a second aspect of the present invention, in the control device for an automatic transmission according to the first aspect, the torque variable engagement means in the released state that is not used at the current gear stage. The control means is configured to execute the control to the engaged state when the fuel cut execution requirement is satisfied.

  The control device for an automatic transmission according to claim 2 controls driving wheels before and after execution of fuel cut by controlling unused torque variable engagement means to an engaged state when a fuel cut execution requirement is satisfied. Can be reduced more appropriately.

  Here, as in the invention described in claim 3, in the control apparatus for an automatic transmission according to claim 1 or 2, from the scheduled start of control to the engaged state of the variable torque engaging means until the completion of fuel cut. There is provided a target output inclination calculation means for obtaining the target inclination of the output reduction of the driving wheel in accordance with the target output of the engine or the driving wheel when the fuel cut is completed. And the said control means should just set the control amount of a torque variable engagement means so that the actual output of a drive wheel may follow the target inclination of the output fall of the said drive wheel.

  According to a fourth aspect of the present invention, in the control device for an automatic transmission according to the first or second aspect, the target inclination of the output reduction of the drive wheels from the time when the fuel cut execution requirement is satisfied to the time when the fuel cut is completed. Is provided according to the target output of the engine or driving wheel when the fuel cut is completed. And the said control means should just set the control amount of a torque variable engagement means so that the actual output of a drive wheel may follow the target inclination of the output fall of the said drive wheel.

  Since the control device for the automatic transmission according to the third and fourth aspects of the present invention gradually decreases the actual output of the driving wheel along the target inclination of the output decrease of the driving wheel without rapidly decreasing, Sudden output fluctuations in the drive wheels can be avoided.

  Further, as the variable torque engagement means, a clutch or / and a brake in the automatic transmission may be used as in the fifth aspect of the invention.

  The control apparatus for an automatic transmission according to the present invention starts unused fuel variable engagement means from when a fuel cut execution requirement is established until fuel cut is actually started (that is, fuel cut is started). By engaging, the output of the drive wheel can be reduced in advance and the output step of the drive wheel before and after the fuel cut can be reduced. Can be suppressed, and a sudden increase in vehicle deceleration can be avoided. Therefore, according to this automatic transmission control device, the driver can decelerate the vehicle without feeling uncomfortable due to a sudden change in the vehicle deceleration.

  Embodiments of an automatic transmission control device according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

  An embodiment of a control device for an automatic transmission according to the present invention will be described with reference to FIGS.

  The control apparatus for the automatic transmission according to the present embodiment is prepared as a function of the electronic control unit (ECU) 1 shown in FIG. The electronic control unit 1 includes a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) that stores a predetermined control program and the like, and a RAM (Random Access Memory) that temporarily stores the calculation result of the CPU. A backup RAM or the like for storing previously prepared information or the like is used.

  First, the automatic transmission 10 to be controlled by the control device and the vehicle on which the automatic transmission 10 is mounted will be described. Here, an FR (front engine / rear drive) vehicle will be described as an example, but the present invention can also be applied to an FF (front engine / front drive) vehicle and a four-wheel drive vehicle. The vehicle exemplified here is equipped with an engine as a drive source (in this case, the internal combustion engine 50 is exemplified), and the power of the internal combustion engine 50 is driven through a power transmission device such as the automatic transmission 10 to drive wheels WL. , WR is transmitted as a driving force.

  The automatic transmission 10 is exemplified as a multi-speed automatic transmission having a plurality of shift speeds with different gear ratios and having six forward speeds and one reverse speed. As shown in FIG. 1, the automatic transmission 10 includes a torque converter 20 that transmits an output torque of the internal combustion engine 50 (hereinafter referred to as “engine torque”) to a gear on the shift stage side, and each shift stage. And a transmission main body 30 including a gear group and the like.

  First, the torque converter 20 will be described in detail.

  As shown in FIG. 1, the torque converter 20 is a fluid transmission device having a pump impeller 21, a turbine runner 22, and a stator 23 housed in a housing (not shown). The housing is filled with a fluid (so-called ATF), and the torque converter 20 transmits torque by the flow of the fluid.

  The pump impeller 21 is an impeller on the torque input side to which engine torque is transmitted from the internal combustion engine 50, and is connected so that the input shaft 11 of the automatic transmission 10 rotates integrally. That is, the engine torque output from the output shaft 51 of the internal combustion engine 50 is directly transmitted to the pump impeller 21 without increasing or decreasing through the input shaft 11. The turbine runner 22 is a torque output-side impeller that outputs engine torque transmitted from the pump impeller 21 side via fluid, and is connected to first to fourth clutches C1 to C4 described later. A torque transmission shaft 41 is connected. The stator 23 is an impeller that controls the flow direction of the fluid between the pump impeller 21 and the turbine runner 22 to amplify the torque, and is connected to the housing of the torque converter 20 via the one-way clutch 24. is there.

  In the torque converter 20, the pump impeller 21 is rotated by the input engine torque, and the fluid delivered along with the rotation is circulated among the pump impeller 21, the turbine runner 22, and the stator 23. In the torque converter 20, the turbine runner 22 is rotated by the circulation of the fluid, and the rotational torque is output via the first torque transmission shaft 41.

  Further, the torque converter 20 is provided with a lockup clutch 25 shown in FIG. 1 for rotating the pump impeller 21 and the turbine runner 22 together. As shown in FIG. 2, the lock-up clutch 25 includes first engagement means 25a coupled to the first torque transmission shaft 41 side and second engagement means 25b coupled to the input shaft 11 side. Thus, switching of the operating state (engaged state or released state) between the first engaging means 25a and the second engaging means 25b is executed by the shift control means of the electronic control unit 1. At least one of the first engaging means 25a and the second engaging means 25b is provided with a friction material at a contact portion when these are pressed.

  For example, when the lock-up clutch 25 is controlled to be in the engaged state and the first engagement means 25a and the second engagement means 25b are completely engaged, the pump impeller 21 and the turbine runner 22 are It is directly connected and rotates as a unit. Thus, the engine torque input to the input shaft 11 is transmitted to the first torque transmission shaft 41 without passing through the fluid between the pump impeller 21 and the turbine runner 22. That is, the lock-up clutch 25 controls the fully engaged state, thereby suppressing the torque transmission loss due to the fluid and directly transmitting the input torque (engine torque) to the first torque transmission shaft 41. On the other hand, the lock-up clutch 25 engages the first engagement means 25a and the second engagement means 25b in a predetermined slip state, so that a part of the input torque (engine torque) is reduced between the pump impeller 21 and the turbine. Since it is transmitted to the first torque transmission shaft 41 via the fluid between the runner 22 and the turbine runner 22, the turbine runner 22 rotates following the pump impeller 21 with a predetermined slip amount.

  Next, the transmission main body 30 will be described in detail.

  As shown in FIG. 1, the transmission main body 30 includes first to fourth clutches C1 to C4, first to third planetary gear devices 31 to 33, and first to fourth clutches C1 to C4. The second to fourth torque transmission shafts 42 to 44 capable of transmitting torque between the first to third planetary gear devices 31 to 33, and the first to fourth brakes B1 to B4. ing.

  The first to fourth clutches C1 to C4 and the first to fourth brakes B1 to B4 are in an operating state (engaged state or released state) between the first engaging means and the second engaging means. ) Is controlled by the shift control means of the electronic control unit 1, and switching of the operation state is executed by the operation of an actuator (not shown). At least one of the first engaging means and the second engaging means is provided with a friction material at a contact portion when these are pressure-bonded. In addition, as the actuator, for example, a hydraulic pressure or an electric actuator (contained as a hydraulic actuator in this embodiment) can be considered. Further, these first to fourth clutches C1 to C4 and the first to fourth brakes B1 to B4 are not only simply switched between the engaged state and the released state, but slipping occurs between the respective engaging means. Any semi-engaged state can be created. The half-engaged state can be controlled to various degrees of engagement (that is, the degree of slippage between the engagement means) by adjusting the control amount of the actuator (if the hydraulic actuator, the supply amount of hydraulic pressure).

  As shown in FIG. 2, the first planetary gear device 31 is a double pinion type planetary gear device, and a sun gear 31a coupled so as to rotate integrally with a second torque transmission shaft 42 in a concentric circle, A ring gear 31b arranged to be concentrically rotated with respect to the second torque transmission shaft 42, a first planetary gear 31c1 meshed with the sun gear 31a, the ring gear 31b and the first planetary gear 31c1 A second planetary gear 31c2 meshed with the first planetary gear 31c1 and a planetary carrier 31d connected to the first planetary gear 31c1 and the second planetary gear 31c2.

  The sun gear 31a is connected to the first torque transmission shaft 41 via the second torque transmission shaft 42 and the third clutch C3, and the third brake B3 is connected to the third brake B3 via the second torque transmission shaft 42 and the one-way clutch F2. 1 is connected to the engaging means B3a. Here, the third clutch C3 has its first engagement means C3a connected to the sun gear 31a via the second torque transmission shaft 42, and its second engagement means C3b is the second clutch C2. It is coupled to the engaging means C2b and the first torque transmission shaft 41 side. The third brake B3 is coupled to the housing (not shown) of the transmission main body 30 with the second engagement means B3b that is engaged with the first engagement means B3a when crimping. The second engagement means B3b of the third brake B3 is coupled to the second engagement means B1b of the first brake B1. The one-way clutch F2 is for preventing the sun gear 31a and the second torque transmission shaft 42 from rotating in the reverse direction (rotation in the direction opposite to the rotation of the first torque transmission shaft 41).

  The ring gear 31b is coupled so as to rotate integrally with a ring gear 32b described later of the second planetary gear device 32, and is coupled to the first engagement means B2a of the second brake B2. The second brake B2 is coupled to the housing of the transmission main body 30 with the second engagement means B2b that is engaged with the first engagement means B2a during crimping.

  The planetary carrier 31d is coupled to the first engagement means B1a of the first brake B1, and is connected to the housing of the transmission main body 30 via the one-way clutch F1. The second engagement means B1b of the first brake B1 is coupled to the housing of the transmission main body 30. Accordingly, the planetary carrier 31d is connected to the second engagement means B1b of the first brake B1 via the one-way clutch F1. The one-way clutch F1 prevents the planetary carrier 31d from rotating in the reverse direction.

  The second planetary gear device 32 is a single-pinion type planetary gear device, and includes a sun gear 32 a coupled to the third torque transmission shaft 43 so as to be integrally rotated concentrically with the third torque transmission shaft 43. A ring gear 32b disposed so as to be able to relatively rotate on a concentric circle, a planetary gear 32c meshed with the sun gear 32a and the ring gear 32b, and a planetary carrier 32d connected to the planetary gear 32c. I have.

  The sun gear 32a is connected to the first torque transmission shaft 41 via the third torque transmission shaft 43 and the fourth clutch C4, and via the third torque transmission shaft 43, the one-way clutch F0 and the first clutch C1. Is also connected to the first torque transmission shaft 41. Further, the sun gear 32 a is connected so as to rotate integrally with a sun gear 33 a (described later) of the third planetary gear device 33 via a third torque transmission shaft 43. Here, the fourth clutch C4 has its first engagement means C4a coupled to the sun gear 32a via the third torque transmission shaft 43, and its second engagement means C4b is the second engagement of the first clutch C1. It is coupled to the coupling means C1b and the first torque transmission shaft 41 side. In the first clutch C1, the first engagement means C1a is coupled to the one-way clutch F0. The one-way clutch F0 is for preventing the sun gear 32a and the third torque transmission shaft 43 from rotating in the reverse direction (rotation in the direction opposite to the rotation of the first torque transmission shaft 41).

  The ring gear 32b is coupled to the ring gear 31b of the first planetary gear device 31 and the first engagement means B2a of the second brake B2.

  The planetary carrier 32d is connected to the first torque transmission shaft 41 via the fourth torque transmission shaft 44 and the second clutch C2, and rotates integrally with a ring gear 33b described later of the third planetary gear device 33. It is connected as follows. As will be described later, since the ring gear 33b is connected to the fourth brake B4, the planetary carrier 32d is connected to the housing of the transmission main body 30 via the ring gear 33b and the fourth brake B4. . The planetary carrier 32d is prevented from rotating in the reverse direction by a one-way clutch F3 provided in parallel with the fourth brake B4. The one-way clutch F3 is connected to the housing of the transmission main body 30.

  The third planetary gear unit 33 is a single-pinion type planetary gear unit, and includes a sun gear 33a coupled to the third torque transmission shaft 43 so as to be integrally rotated concentrically, and the third torque transmission shaft 43. A ring gear 33b disposed so as to be able to relatively rotate on a concentric circle, a planetary gear 33c meshed with the sun gear 33a and the ring gear 33b, and a planetary carrier 33d connected to the planetary gear 33c. I have.

  The ring gear 33b is connected to the planetary carrier 32d of the second planetary gear device 32 as described above, and is connected to the first engagement means B4a of the fourth brake B4. The fourth brake B4 is coupled to the housing of the transmission main body 30 with the second engagement means B4b that is engaged with the first engagement means B4a during pressure bonding.

  The planetary carrier 33d is coupled to rotate integrally with the output shaft 12 of the automatic transmission 10. That is, in the automatic transmission 10, the shifted engine torque is output via the planetary carrier 33 d of the third planetary gear device 33.

  As shown in FIG. 1, a propulsion shaft 61 that transmits rotational torque to the differential device 60 is coupled to the output shaft 12. The differential device 60 distributes the rotational torque output from the automatic transmission 10 to the left and right drive shafts DL and DR, and generates drive force on the left and right drive wheels WL and WR. The propulsion shaft 61 and the differential device 60 are connected by meshing between a drive pinion gear 62 coupled to the propulsion shaft 61 and a ring gear 63 of the differential device 60.

  In the automatic transmission 10 configured as described above, the shift control means appropriately engages the first to fourth clutches C1 to C4, the first to fourth brakes B1 to B4, and the one-way clutches F0 to F3 described above. Alternatively, the gear position is switched by controlling to the released state. The control operation to the engaged state or the released state is executed by a hydraulic control circuit (not shown) that receives a command from the shift control means. The hydraulic control circuit is configured to include a linear solenoid valve and an on / off solenoid valve, and controls the excitation state or the non-excitation state of the linear solenoid valve and the like to switch the hydraulic circuit. The operating states (engaged state or released state) of the first to fourth clutches C1 to C4 and the like are controlled.

  In this vehicle, a detection signal of a crank angle sensor 71 that detects the rotational angle position (so-called crank angle) of the output shaft 51 of the internal combustion engine 50 and an accelerator position sensor that detects the accelerator operation amount (accelerator opening) of the driver. 72, a detection signal from a throttle position sensor 73 that detects a valve opening angle of a throttle valve (not shown), a detection signal from a shift position sensor 74 that detects a shift range position, and a vehicle speed sensor 75 that detects a vehicle speed. The detection signal is input to the electronic control unit 1. The shift range is a travel range of the automatic transmission 10 selected by the driver operating the shift lever, for example. Typical examples include a P range for parking where the automatic transmission 10 is mechanically locked so that the drive wheels WL and WR do not rotate, and a reverse gear stage for the automatic transmission 10 is selected. An R range that allows the vehicle to travel backward, an N range that sets the automatic transmission 10 in a neutral state (that is, a state in which no torque is transmitted between the input shaft 11 and the output shaft 12), and automatic There is known a D range in which the transmission 10 is allowed to select a forward gear to allow the vehicle to travel forward.

  The engine control means (engine control means) of the electronic control unit 1 calculates the engine speed based on, for example, a detection signal related to the crank angle, and further controls the fuel injection amount, ignition timing, etc. to generate the internal combustion engine 50. Adjust the output torque.

  Further, the shift control means of the electronic control unit 1 sets a target shift stage of the automatic transmission 10 based on, for example, the accelerator operation amount, the shift range position, the vehicle speed, etc., and automatically changes according to the set target shift stage. The operation of the transmission 10 is controlled. For example, when the D range is selected, the shift control means selects the target shift from among the forward shift speeds (the first gear stage “1st” to the sixth gear stage “6th”) based on the accelerator operation amount or the like. The first to fourth clutches C1 to C4, the first to fourth brakes B1 to B4, and the one-way clutches F0 to F3 are controlled so that the target gear is selected.

  FIG. 3 shows the respective speeds of the automatic transmission 10 (first speed gear stage “1st”, second speed gear stage “2nd”, third speed gear stage “3rd”, and fourth speed gear stage “4th”. , 5th speed gear stage “5th”, 6th speed gear stage “6th”, reverse gear stage “R”), first to fourth clutches C1 to C4, first to fourth brakes B1 to B4, and The operating state of the one-way clutches F0 to F3 is shown. In the operation table of FIG. 3, “◯” represents an engaged state, and “(◯)” represents an engaged state during engine braking. “Δ” represents a state that is in an engaged state but not related to torque transmission. No mark indicates a released state.

  For example, when the driver selects the N range, the shift control means puts all of the first to fourth clutches C1 to C4, the first to fourth brakes B1 to B4, and the one-way clutches F0 to F3 into a released state. Control.

  Further, when the driver selects the D range and, for example, the first gear is selected by the speed change control means, the speed change control means controls the first clutch C1 and the one-way clutches F0 and F3 to be engaged, In addition, the other second to fourth clutches C2 to C4 and the one-way clutches F1 and F2 are controlled to be released.

  Further, when the shift control means selects, for example, a shift from the first speed gear stage to the second speed gear stage, the shift control means changes the second and third brakes B2 and B3 from the released state to the engaged state. And the fourth brake B4 is controlled from the engaged state to the released state. Further, at that time, the shift control means controls the one-way clutches F1 and F2 from the released state to the engaged state, and controls the one-way clutch F3 from the engaged state to the released state.

  Further, when the shift control means selects, for example, a shift from the fourth speed gear stage to the third speed gear stage, the shift control means controls the second clutch C2 from the engaged state to the released state, and The first brake B1 and the one-way clutch F1 are controlled from the released state to the engaged state.

  By the way, while the vehicle is decelerating, so-called fuel cut control is executed to stop the fuel supply to the combustion chamber of the internal combustion engine 50 when a predetermined requirement is satisfied, for example, in order to improve fuel efficiency. There is a case. Hereinafter, the predetermined requirement is referred to as a fuel cut execution requirement, and the fuel cut execution requirement is a well-known requirement in this technical field. For example, the vehicle speed, the engine speed, the water temperature of the internal combustion engine 50, etc. Judgment based on. The water temperature is detected by a water temperature sensor 76 shown in FIG. In the electronic control device 1 of this embodiment, when the fuel cut execution requirement is satisfied, the engine control means controls an ISC (idle speed control) valve (not shown) of the internal combustion engine 50 to execute idle speed control after a predetermined time has elapsed. Then, the fuel cut execution means is caused to execute fuel cut control.

  Here, in the internal combustion engine 50, as shown in FIG. 4, when the shift stage of the automatic transmission 10 is kept constant (n stage) and compared at the same engine speed Ne, the output (engine torque Te or engine output) It can be seen that Fe) is significantly lower after the execution than before the fuel cut. In other words, the internal combustion engine 50 has a large difference (hereinafter referred to as “output step”) in output (engine torque Te or engine output Fe) before and after execution of fuel cut. The output level difference of the internal combustion engine 50 becomes the output level difference in the drive wheels WL and WR as it is, causing output fluctuations in the drive wheels WL and WR, giving the driver a sense of incongruity. The output step of the internal combustion engine 50 includes an engine torque step dTe that is a step of the engine torque Te and an engine output step dFe that is a step of the engine output Fe. The output steps of the driving wheels WL and WR include a driving torque step dTd that is a step of the driving torque Td and a driving force step dFd that is a step of the driving force Fd. The solid line in FIG. 4 represents an example of the output of the internal combustion engine 50 before the fuel cut is executed, and shows a state in which the idle speed control is further executed when the throttle is fully closed. Moreover, the broken line represents an example of the output of the internal combustion engine 50 after the fuel cut is executed, and shows a state where only the friction torque is generated.

  Therefore, in the present embodiment, the output step of the drive wheels WL and WR before and after the execution of the fuel cut is reduced by generating load torque (loss torque) in the automatic transmission 10. Therefore, the control device for the automatic transmission 10 according to the present embodiment is configured to execute the output level difference suppression control.

  The load torque (loss torque) is transmitted to the drive wheels WL and WR through the output shaft 12 of the automatic transmission 10 and the like, and becomes a load in the drive wheels WL and WR, so the output of the drive wheels WL and WR is reduced. Let Then, by gradually reducing the output of the drive wheels WL and WR in advance with the load torque (loss torque) before the fuel cut control is executed, the drive before and after the fuel cut is executed when the fuel cut control is completed. The output level difference between the wheels WL and WR is reduced.

  In the output step restraint control, the rotational torque at the output shaft 12 of the automatic transmission 10 can be changed by engaging or releasing the components in the automatic transmission 10 (hereinafter referred to as “torque variable engagement means”). "). The variable torque engagement means is selected from a plurality according to a desired shift stage, and the selected members are controlled to be engaged with each other, thereby shifting to the shift stage. Is to do. When the output level difference suppression control is performed, when the fuel cut execution requirement is satisfied, the torque variable engagement means in the released state that is not used at the current shift level is controlled to be in the engaged state, and the automatic transmission 10 generates a load torque (loss torque).

  Specifically, in the automatic transmission 10 of the present embodiment, the first to fourth clutches C1 to C4 and the first to fourth brakes B1 to B4 correspond to the variable torque engagement means. In the output level difference suppression control, at least one of the first to fourth clutches C1 to C4 and the first to fourth brakes B1 to B4 other than the gear that is currently in use is released. To the engaged state, thereby applying a load to the interior of the automatic transmission 10 to generate a loss torque. Which clutch or brake is to be engaged when executing the output level difference suppression control is determined in advance according to map data or the like as will be described later according to the required loss torque. The engagement state of the clutch or brake to be controlled by the output level difference suppression control is, in principle, a half-engagement state in which slippage occurs between the engagement means, but the rotation of the rotation member such as the output shaft 12 is performed. If it does not stop completely, it may be in a fully engaged state in which such slip is eliminated.

  Below, the operation | movement of the output level | step difference suppression control and the control apparatus of the automatic transmission which performs this are demonstrated using the flowchart of FIG.

  First, the output level difference suppression control execution unit (control unit) of the electronic control device 1 acquires information necessary for this control (step ST1). The information includes the acceleration in the vehicle longitudinal direction detected by the longitudinal acceleration sensor 77, the vehicle speed detected by the vehicle speed sensor 75, the wheel speeds of the drive wheels WL and WR detected by the wheel speed sensor 78, and the accelerator position sensor 72. For example, the accelerator operation amount (accelerator opening).

  The vehicle travel state determination means of the electronic control unit 1 determines whether or not the vehicle is in a deceleration state (step ST2). For example, this determination is performed using the detection signal of the longitudinal acceleration sensor 77 shown in FIG. The longitudinal acceleration sensor 77 is means for detecting acceleration in the longitudinal direction of the vehicle, and the vehicle running state determination means is in a deceleration state if the acceleration information obtained from the detection signal indicates a value indicating deceleration. Judgment is made. In step ST2, the determination may be made using the detection signal of the vehicle speed sensor 75. In this case, the vehicle running state determination means calculates the rate of change of the vehicle speed obtained from the detection signal of the vehicle speed sensor 75, and if the rate of change is a value indicating deceleration, determines that the vehicle is in a deceleration state. Do. Further, the vehicle running state determining means calculates a change rate of the wheel speed obtained from the detection signal of the wheel speed sensor 78 of the drive wheels WL and WR, and if the change rate is a value indicating deceleration, the vehicle decelerates. You may determine that it exists in a state.

  If it is determined in step ST2 that the vehicle is not in a decelerating state, the shift control means of the electronic control device 1 once ends this control.

  On the other hand, when it is determined in step ST2 that the vehicle is decelerating, the driver request determination unit of the electronic control device 1 is requesting that the driver request a vehicle speed increase or deceleration. Is determined (step ST3).

  For example, if the accelerator opening obtained from the detection signal of the accelerator position sensor 72 tends to increase, the vehicle running state determination means determines that a speed increase request has been made, and if the accelerator opening tends to decrease. It is determined that a deceleration request has been made. The accelerator position sensor 72 of the present embodiment detects an accelerator opening that indicates an increasing tendency when the driver depresses an accelerator pedal (not shown), and an accelerator opening that indicates a decreasing tendency when the driver returns the accelerator pedal. Detected.

  Here, when the driver returns the accelerator pedal, the driver may slowly return the accelerator pedal or may return it quickly. In general, the driver slowly returns the accelerator pedal for speed adjustment when, for example, the vehicle travels at a constant speed after accelerating to a predetermined vehicle speed. On the other hand, if the driver wants to decelerate the vehicle, the driver quickly returns the accelerator pedal, and if necessary, performs a braking operation to generate a braking force on the wheels. Therefore, the vehicle travel state determination means of this embodiment determines that a deceleration request has been made when the driver's accelerator pedal return speed (hereinafter referred to as "accelerator return speed") is high. For example, if the rate of change of the accelerator opening in the decreasing direction related to the accelerator return speed is greater than a predetermined threshold value, the vehicle running state determination means has a high accelerator return speed and a driver has requested deceleration. Judgment is made. On the other hand, if the rate of change of the accelerator opening in the decreasing direction is equal to or less than a predetermined threshold, the vehicle running state determination means determines that the accelerator return speed is slow and that the driver has not requested deceleration.

  If it is determined in step ST3 that the speed increase is requested, the shift control means of the electronic control unit 1 once ends this control.

  On the other hand, when it is determined that the deceleration request is made in step ST3, the fuel cut determination means of the electronic control unit 1 determines whether or not the fuel cut execution requirement is satisfied (step ST4). The fuel cut execution requirements in step ST4 are those when the above-described idle speed control is not being executed.

  If it is determined in step ST4 that the fuel cut execution requirement is not satisfied, the shift control means of the electronic control unit 1 once ends this control.

  On the other hand, if it is determined in step ST4 that the fuel cut execution requirement is satisfied, the output level difference calculating means of the electronic control unit 1 outputs the output level difference (engine torque level difference dTe or engine level difference) of the internal combustion engine 50 before and after fuel cut execution. A predicted value of the output step dFe) (hereinafter referred to as “predicted output step”) is obtained (step ST5). The predicted output step of the internal combustion engine 50 includes a predicted engine torque step dTep that is a predicted value of the engine torque step dTe, and a predicted engine output step dFep that is a predicted value of the engine output step dFe. Here, since the gear position of the automatic transmission 10 is maintained as it is, the predicted output level difference of the internal combustion engine 50 becomes the predicted output level level before and after the fuel cut is performed on the drive wheels WL and WR.

  The predicted output step (predicted engine torque step dTep or predicted engine output step dFep) of the internal combustion engine 50 is the target output (target engine torque Tetgt or target engine output Fetgt) of the internal combustion engine 50 according to the driver's deceleration request, Calculation is performed based on the estimated output (estimated engine torque Tep or estimated engine output Fep) of the internal combustion engine 50 at the start of fuel cut. The predicted engine torque step dTep is obtained by subtracting the target engine torque Tetgt from the estimated engine torque Tep of the internal combustion engine 50 at the start of fuel cut, as shown in the following equation 1. Further, the predicted engine output level difference dFep is obtained by subtracting the target engine output Fetgt from the estimated engine output Fep of the internal combustion engine 50 at the start of the fuel cut, as shown in Equation 2 below.

  dTep = Tep−Tetgt (1)

  dFep = Fep-Fetgt (2)

  Here, the target output of the internal combustion engine 50 according to the driver's deceleration request realizes the target output (target drive torque Tdtgt or target drive force Fdtgt) of the drive wheels WL and WR according to the driver's deceleration request. This is a target value of the output generated in the internal combustion engine 50 while the automatic transmission 10 is kept at the current gear position. For example, the target output of the internal combustion engine 50 is output to the output step calculating means using the gear ratio at the current gear position of the automatic transmission 10, the final reduction ratio in the differential device 60, and the target outputs of the drive wheels WL and WR. Can be asked. The target outputs of the drive wheels WL and WR are derived using a known calculation method in this technical field, and are calculated by the drive wheel target output calculation means of the electronic control unit 1.

  The estimated output (estimated engine torque Tep or estimated engine output Fep) of the internal combustion engine 50 at the start of fuel cut is the time until fuel cut is started (hereinafter referred to as “fuel cut start time”) dtfcs. Based on the current output of the internal combustion engine 50 (engine torque Tenow or engine output Fenow) that can be determined from the control command value to the internal combustion engine 50 and the current gradient of the deceleration state of the vehicle, the following formula 3 or formula 4 can be obtained. In other words, the inclination of the current deceleration state of the vehicle is an output reduction amount (engine torque reduction amount QTe or engine output reduction amount QFe) of the internal combustion engine 50 per unit time, which is a negative value here. And

  Tep = Tenow + QTe × dtfcs (3)

  Fep = Fenow + QFe × dtfcs (4)

  As for the fuel cut start time dtfcs, for example, if the predicted time for achieving the target output of the internal combustion engine 50 (hereinafter referred to as “target output achievement predicted time”) dtp can be clarified, at what timing the fuel cut is started. Since it can be determined whether it is good, it can be obtained by subtracting the time dtfc from the start to the end of the fuel cut from the target output achievement prediction time dtp as shown in the following equation 5. Note that the target output achievement prediction time dtp is set to a time during which the reaction on the vehicle side (specifically, the magnitude of vehicle deceleration, the time of start-up, etc.) associated with the driver's deceleration request can be felt without a sense of incongruity. The map data representing these correspondence relationships prepared in advance may be used. The time dtfc from the start to the end of the fuel cut is the time from when a fuel injection prohibition command is transmitted to a fuel injection valve (not shown) until the actual fuel injection stops, and basically the response of the fuel injection valve Apply time.

  dtfcs− = dtp−dtfc (5)

  The output reduction amount (engine torque reduction amount QTe or engine output reduction amount QFe) per unit time is obtained from, for example, the change rate of the engine speed Ne, the change rate of the vehicle longitudinal acceleration, or the like.

  In step ST5, the predicted output step (predicted driving torque step dTdp or predicted driving force step dFdp) of the drive wheels WL and WR may be obtained. In this case, the predicted output steps of the drive wheels WL and WR are the target output (target drive torque Tdtgt or target drive force Fdtgt) of the drive wheels WL and WR, and the estimated output of the drive wheels WL and WR at the start of fuel cut ( (Estimated driving torque Tdp or estimated driving output Fdp). The predicted drive torque step dTdp is obtained by subtracting the target drive torque Tdtgt from the estimated drive torque Tdp of the drive wheels WL and WR at the start of fuel cut, as shown in Equation 6 below. Further, the predicted driving force level difference dFdp is obtained by subtracting the target driving force Fdtgt from the estimated driving output Fdp of the driving wheels WL and WR at the start of fuel cut, as shown in the following Expression 7.

  dTdp = Tdp−Tdtgt (6)

  dFdp = Fdp−Fdtgt (7)

  Subsequently, the control target selection means of the electronic control device 1 determines the predicted output step (predicted engine torque step dTep or predicted engine output step dFep) of the internal combustion engine 50 before or after execution of the fuel cut obtained in step ST5 or the drive wheels WL, WR. Of the first to fourth clutches C1 to C4 and the first to fourth brakes B1 to B4 based on the predicted output step (the predicted drive torque step dTdp or the predicted drive force step dFdp). At least one or one set is selected as a control target from those other than those related to the stage (step ST6).

  In this step ST6, a clutch or brake capable of generating at least a loss torque corresponding to the predicted output step of the internal combustion engine 50 in the half-engaged state is selected. The selection is performed, for example, using map data that has been obtained in advance through experiments and simulations about a clutch, a brake, and a combination of the clutch and the brake that can generate a desired loss torque. For example, when the vehicle is operating at the third speed gear stage (3rd), the second clutch C2, the second brake B2, and the fourth brake B4 can be used as control targets for the output step suppression control as shown in FIG. . Therefore, in this case, at least one of the second clutch C2, the second brake B2, and the fourth brake B4 that can generate a desired loss torque, or the second clutch C2, the second brake B2, and One set that can generate a desired loss torque selected from the fourth brake B4 is selected.

  Here, in step ST6, the selection of the control target may be performed based on the predicted output step (the predicted drive torque step dTdp or the predicted drive force step dFdp) of the drive wheels WL and WR.

  Further, the target output inclination calculation means of the electronic control unit 1 starts from the present time until the target output is generated in the drive wheels WL and WR (in other words, until the fuel cut control is completed). The target slope (hereinafter referred to as “target output slope”) Sdtgt for the output reduction of WL and WR is obtained (step ST7).

  The target output slope Sdtgt of the drive wheels WL and WR is the same as the target slope (target output slope) Setgt of the output reduction of the internal combustion engine 50 from the present time until the target output is generated. For this reason, here, the target output gradient Sdtgt of the drive wheels WL and WR is derived by obtaining the target output gradient Setgt of the internal combustion engine 50. The target output gradient Setgt of the internal combustion engine 50 includes a target engine torque gradient STetgt that indicates a gradient of decrease in engine torque and a target engine output gradient SFetgt that indicates a gradient of decrease in engine output. The target output gradient Setgt (target engine torque gradient STetgt or target engine output gradient SFetgt) of the internal combustion engine 50 is the current output of the internal combustion engine 50 (engine torque Tenow or engine output Fenow) as shown in the following equation 8 or equation 9. ), The target output (target engine torque Tetgt or target engine output Fetgt) of the internal combustion engine 50 and the target output achievement predicted time dtp.

  STetgt = (Tenow−Tetgt) / dtp (8)

  SFetgt = (Fenow−Fetgt) / dtp (9)

  Here, the target engine torque gradient STetgt is the same as the target drive torque gradient STdtgt indicating the gradient of decrease in the drive torque in the drive wheels WL and WR. Therefore, the target drive torque gradient STdtgt is based on Equation 8 above. Further, it can be obtained using the following formula 10. Further, the target engine output Fetgt is the same as the target driving force gradient SFdtgt indicating the gradient of the decrease in driving force in the driving wheels WL and WR. For this reason, the target driving force gradient SFdtgt is based on Equation 9 below. It can obtain | require using the Formula 11 of.

  STdtgt = (Tenow−Tetgt) / dtp (10)

  SFdtgt = (Fenow−Fetgt) / dtp (11)

  The target output gradient Sdtgt (target drive torque gradient STdtgt or target drive force gradient SFdtgt) of the drive wheels WL and WR is the current output of the drive wheels WL and WR (drive torque Tdnow or drive force Fdnow) and the drive wheels WL, You may obtain | require based on the target output (target drive torque Tdtgt or target drive force Fdtgt) of WR, and target output achievement estimated time dtp. In this case, the following formula 12 or formula 13 is applied.

  STdtgt = (Tdnow−Tdtgt) / dtp (12)

  SFdtgt = (Fdnow−Fdtgt) / dtp (13)

  After determining the control target and the target value in this way, the output level difference suppression control execution means of the electronic control device 1 obtains a control amount for the control target selected in step ST6 (step ST8). The control amount here is the amount of engagement of the clutch or brake to be controlled (in other words, the degree of engagement or the degree of slippage between the engaging means). This refers to the controlled variable (hydraulic command pressure shown in FIG. 6). This control amount is determined so that the actual output (actual drive torque Tdreal or actual drive force Fdreal) of the drive wheels WL and WR follows the target output gradient Sdtgt of the drive wheels WL and WR.

  Then, the output level difference suppression control execution means controls the actuator related to the controlled object according to the control amount, and executes control of the controlled object (that is, output level difference suppression control) (step ST9).

  As a result, the clutch or brake to be controlled in the automatic transmission 10 is in a half-engaged state, and a loss torque is generated on the output shaft 12 as shown in FIG. Along with this, in the driving wheels WL and WR, the output (driving torque Td or driving force Fd) is reduced by the amount corresponding to the loss torque more than when the output level difference suppression control is not controlled. At that time, the actual output of the drive wheels WL and WR (actual drive torque Tdreal or actual drive force Fdreal) does not decrease rapidly but gradually decreases along the target output gradient Sdtgt of the drive wheels WL and WR. Go. For this reason, in the output level difference suppression control, sudden output fluctuations in the drive wheels WL and WR can be avoided.

  Here, during the execution of the output step restraint control, when the engine control means executes the idle speed control when the idle speed control execution time comes, and then when the fuel cut control time comes The fuel cut execution means executes fuel cut control.

  Thereafter, the actual output inclination calculating means of the electronic control unit 1 calculates the actual output decrease inclination of the driving wheels WL and WR (hereinafter referred to as “actual output inclination”) Sdreal (step ST10).

  As the actual output gradient Sdreal of the drive wheels WL and WR, an actual drive torque gradient STdreal indicating a decrease in the drive torque of the actual drive wheels WL and WR, or a decrease in the drive force of the actual drive wheels WL and WR. There is an actual driving force gradient SFdreal that represents the gradient, and is estimated based on, for example, the rate of change of the wheel speed (detected by the wheel speed sensor 78) of the drive wheels WL and WR. Further, the actual output slope Sdreal may be obtained based on detection of a change in the rotational torque of the drive wheels WL and WR from the detection signal of the torque sensor 79 provided on the drive shafts DL and DR. Here, under the situation where the friction coefficient of the road surface is low, the drive wheels WL and WR may slip, so the actual output slope Sdreal of the drive wheels WL and WR is accurately estimated from the change rate of the wheel speed. There are cases where it is not possible. For this reason, it is desirable that the actual output inclination calculation means accurately estimate the actual output inclination Sdreal of the drive wheels WL and WR based on the change in the rotational torque of the output shaft 12 of the automatic transmission 10. The rotational torque may be detected using a torque sensor 80 provided on the output shaft 12.

  The output step suppression control execution means of the present embodiment compares the actual output slope Sdreal of the drive wheels WL and WR with the target output slope Sdtgt, and determines whether or not the absolute value of these differences is smaller than a predetermined value S0. Determine (step ST11).

  When the absolute value of the difference between the target output slope Sdtgt and the actual output slope Sdreal is equal to or greater than the predetermined value S0, the control target is set to keep the output steps of the drive wheels WL and WR low when the target output achievement prediction time dtp is reached. It is necessary to readjust the control amount. Therefore, in this case, the process returns to step ST8, and the control amount for the controlled object is recalculated taking into account the difference between the target output slope Sdtgt and the actual output slope Sdreal. Then, the output level difference suppression control execution unit controls the actuator with the new control amount, and performs the comparison determination in step ST11 again.

  On the other hand, when the absolute value of the difference between the target output slope Sdtgt and the actual output slope Sdreal is smaller than the predetermined value S0, it indicates that the output level difference suppression control is executed as scheduled. For this reason, in this case, the output level difference suppression control execution means determines whether or not the fuel cut control is completed (in other words, whether or not the target output achievement predicted time dtp has been reached) (step ST12).

  If the fuel cut control has not yet been completed, the output step suppression control execution means continues the output step suppression control. At that time, the clutches and brakes to be controlled are controlled by a control amount that can suppress the output level difference of the drive wheels WL and WR when the target output achievement prediction time dtp is reached. However, here, in order to further improve the accuracy of the output level difference suppression control, the process returns to step ST8 to recalculate the control amount for the controlled object.

  When it is determined in step ST12 that the fuel cut control has been completed, the output level difference suppression control execution means reaches the target output achievement prediction time dtp and the target output is generated in the internal combustion engine 50 and the drive wheels WL and WR. The output level difference suppression control is terminated.

  Thus, when the output level difference suppression control is completed (that is, when the fuel cut control is completed), the output level difference is smaller in the drive wheels WL and WR than when the output level difference suppression control is not controlled.

  As described above, the control device for the automatic transmission 10 according to the present embodiment enables the first to fourth clutches C1 to C4 and the first to fourth brakes B1 to B4 when the fuel cut execution requirement is satisfied. By controlling the unused one in the engaged state and generating a load torque (loss torque) of an appropriate magnitude in advance in the automatic transmission 10 before the fuel cut control is executed, The output level difference between the drive wheels WL and WR before and after execution can be reduced. For this reason, in the vehicle, output fluctuations before and after the execution of fuel cut in the drive wheels WL and WR are suppressed, so that a rapid increase in vehicle deceleration can be avoided. Therefore, according to the control device of the automatic transmission 10, the driver does not feel uncomfortable due to the sudden change in the vehicle deceleration, so that the driver can decelerate the vehicle with good drivability. .

  By the way, in the above-described embodiment, when the fuel cut execution requirement is satisfied, the unused ones of the first to fourth clutches C1 to C4 and the first to fourth brakes B1 to B4 are engaged. And the load torque (loss torque) that gradually increases with respect to the automatic transmission 10 is generated from when the fuel cut execution requirement is satisfied. This aspect can appropriately reduce the output step of the drive wheels WL and WR before and after the fuel cut is performed and eliminate the step before the fuel cut due to the generation of the load torque (loss torque). This is useful because output fluctuations in the drive wheels WL and WR can be avoided. However, the control start timing of the unused ones to the engaged state is not necessarily limited to such a mode. For example, the control of the unused one to the engaged state is started before the fuel cut is started (that is, from when the fuel cut execution requirement is established until the fuel cut is actually started). This also allows the driver to decelerate the vehicle with good drivability by avoiding a sudden increase in vehicle deceleration.

  At that time, the load torque (loss torque) is increased so as to eliminate the output level difference between the drive wheels WL and WR before and after the fuel cut, for example, as in the above-described example. For example, the target output inclination calculation means at that time indicates the target inclination of the output decrease of the drive wheels WL and WR from the time when control of the unused one to the engaged state is started until the fuel cut is completed. It is determined according to the target output of the internal combustion engine 50 or the drive wheels WL and WR at the time. The load torque (loss torque) based on the target inclination is generated from the start of the control to the engaged state of the unused one. Thereby, the output level difference of the drive wheels WL and WR before and after the execution of the fuel cut can be appropriately reduced and eliminated. On the other hand, if there is a possibility that the target inclination may cause output fluctuations in the drive wheels WL and WR due to the generation of load torque (loss torque), the target output inclination calculation means starts from when the fuel cut execution requirement is satisfied. The target inclination of the output reduction of the drive wheels WL and WR until the fuel cut is completed is determined according to the target output of the internal combustion engine 50 or the drive wheels WL and WR at the time of the fuel cut completion. If the target inclination is such that output fluctuations are not generated in the drive wheels WL and WR due to the generation of load torque (loss torque), the load torque (loss torque) is controlled to the engagement state of the unused one. Generate from the beginning. Thereby, the output step of the drive wheels WL and WR before and after the execution of the fuel cut can be reduced while avoiding the output fluctuation of the drive wheels WL and WR before the start of the fuel cut due to the generation of the load torque (loss torque). .

  As described above, the control device for an automatic transmission according to the present invention is useful for a technique for suppressing an output step difference of a drive wheel that occurs before and after execution of fuel cut.

It is a figure which shows an example of the vehicle to which the control apparatus of the automatic transmission which concerns on this invention is applied. It is a figure which shows an example of the automatic transmission which is the application object of the control apparatus which concerns on this invention. It is an operation | movement table | surface of the automatic transmission of a present Example. It is a figure explaining the output level | step difference of an internal combustion engine before and after execution of a fuel cut. It is a flowchart explaining the output level | step difference suppression control by the control apparatus of the automatic transmission which concerns on this invention. 6 is a time chart showing the output of the internal combustion engine, the loss torque and command pressure of the automatic transmission, and the output of the drive wheels when executing the output step suppression control.

Explanation of symbols

1 Electronic control unit (ECU)
DESCRIPTION OF SYMBOLS 10 Automatic transmission 11 Input shaft 12 Output shaft 20 Torque converter 30 Transmission main body 31,32,33 Planetary gear device 50 Internal combustion engine 60 Differential device 71 Crank angle sensor 72 Accelerator position sensor 73 Throttle position sensor 74 Shift position sensor 75 Vehicle speed Sensor 76 Water temperature sensor 77 Longitudinal acceleration sensor 78 Wheel speed sensor 79, 80 Torque sensor B1 1st brake B2 2nd brake B3 3rd brake B4 4th brake C1 1st clutch C2 2nd clutch C3 3rd clutch C4 4th clutch DL , DR Drive shaft WL, WR Drive wheel

Claims (5)

If the predetermined fuel cut execution requirement is met when the vehicle decelerates, the engine is mounted on the vehicle that performs the fuel cut, and the one selected from the plurality of variable torque engaging means according to the gear position is controlled to the engaged state. In the automatic transmission control device that performs the shifting operation to the shift stage,
Control means for controlling the variable torque engagement means in the released state that is not used at the current gear stage from when the fuel cut execution requirement is satisfied to when actual fuel cut is started. A control device for an automatic transmission, characterized by comprising:   The control means is configured to execute the control to the engagement state of the variable torque engagement means in the released state that is not used at the current gear stage when the fuel cut execution requirement is satisfied. The control device for an automatic transmission according to claim 1. The target inclination of the output reduction of the drive wheel from the scheduled start of control to the engagement state of the variable torque engagement means to the completion of the fuel cut depends on the target output of the engine or the drive wheel at the completion of the fuel cut. A target output slope calculating means to be obtained is provided,
The control means is configured to set a control amount of the variable torque engagement means so that an actual output of the driving wheel follows a target inclination of an output reduction of the driving wheel. 2. A control device for an automatic transmission according to 2. Provided is a target output slope calculating means for obtaining a target slope of output reduction of the drive wheel from when the fuel cut execution requirement is satisfied to when the fuel cut is completed according to a target output of the engine or the drive wheel when the fuel cut is completed. ,
The control means is configured to set a control amount of the variable torque engagement means so that an actual output of the driving wheel follows a target inclination of an output reduction of the driving wheel. 2. A control device for an automatic transmission according to 2.   5. The automatic transmission control apparatus according to claim 1, wherein the torque variable engagement means is a clutch or / and a brake in the automatic transmission.

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