JP2015102190A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress or prevent a belt slide of a belt-type continuously variable transmission even if an abrupt brake of a vehicle is executed during the execution of idling stop control at the forward traveling of the vehicle.SOLUTION: The rotation of an input-side rotating inertia body (that is, a rotating inertial body on an input shaft 30) of a continuously variable transmission 18 can be forcibly stopped conforming to an abrupt brake of a vehicle 10, or inertial torque generated by the input-side rotating inertia body of the continuously variable transmission 18 is shared to a clutch LU and/or a reverse brake B1 at the abrupt brake of the vehicle 10. By this constitution, the inertia torque inputted to the continuously variable transmission 18 can be alleviated. Therefore, even if the abrupt brake of the vehicle 10 is executed during the execution of deceleration eco-run control, a belt slide of the continuously variable transmission 18 can be suppressed or prevented.

Description

  The present invention relates to a control device for a vehicle including a belt type continuously variable transmission.

  2. Description of the Related Art A vehicle control apparatus that performs idling stop control for stopping an engine while a vehicle is traveling forward is well known in a vehicle including a belt type continuously variable transmission. For example, this is the control device for an idle stop vehicle described in Patent Document 1. In Patent Document 1, when a predetermined engine stop condition is satisfied during vehicle deceleration, the clutch transmission torque transmitted to the primary pulley is the transmission torque of the continuously variable transmission (particularly, the transmission torque of the primary pulley). In order not to exceed, the supply hydraulic pressure to the primary pulley is maintained to prevent a rapid decrease, and the actual clutch pressure of the starting clutch is forcibly (rapidly) reduced, so that when the idle stop enters during deceleration (i.e., the engine stops) To prevent or suppress the occurrence of belt slip when the hydraulic pressure generated by a mechanical oil pump is reduced.

JP 2012-241746 A

  By the way, when the idling stop control of the engine is being executed while the vehicle is traveling forward, there is a possibility that an abrupt deceleration operation for suddenly decelerating the vehicle by the driver may be performed. In such a sudden deceleration operation, the higher the vehicle speed, the more rapid the deceleration operation, or the lower the road surface, the easier the braking (rotation reduction) of the wheels, and the greater the speed of the rotating inertial body. The inertia torque is easily input to the continuously variable transmission. At this time, the input inertia torque exceeds the torque capacity (belt clamping pressure) of the continuously variable transmission, and belt slipping may occur. On the other hand, when engine idling stop control is being performed while the vehicle is running, hydraulic pressure can be supplied to a continuously variable transmission or the like by an electric oil pump as an alternative to a mechanical oil pump driven to rotate by the engine. Conceivable. However, when the electric oil pump is temporarily used, a small electric oil pump having a smaller discharge flow rate than the mechanical oil pump is provided in consideration of the arrangement space and cost. For this reason, belt slip may still occur during idling stop control. The above-described problem is not known.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is that even if the vehicle is suddenly braked during the idling stop control while the vehicle is traveling forward, the belt type An object of the present invention is to provide a vehicle control device capable of suppressing or preventing belt slippage of a continuously variable transmission.

  The gist of the first invention for achieving the above object is that (a) an engine, a fluid transmission device having a lock-up clutch, a planetary gear device and the planetary gear device are selectively rotated integrally. A forward drive power having a clutch element and a brake element for selectively connecting one of the rotating elements of the planetary gear unit to a non-rotating member, and engaging the clutch element and releasing the brake element A forward / reverse switching device that establishes a reverse power transmission path by disengaging the clutch element and engaging the brake element while establishing a transmission path; and a power transmission path between the forward / backward switching device and the drive wheels. In a vehicle including a belt type continuously variable transmission that constitutes a part of the vehicle, it is possible to execute an idling stop control that stops the engine while the vehicle is traveling forward. A vehicle control device capable of engaging at least one of the lock-up clutch and the brake element when the vehicle is suddenly braked during execution of the idling stop control; There is.

  In this way, the rotation of the rotary inertia body on the input side of the belt type continuously variable transmission can be forcibly stopped in accordance with the sudden braking of the vehicle. Alternatively, when the vehicle is suddenly braked, an inertia torque due to a rotary inertia body on the input side of the belt type continuously variable transmission is shared by the lockup clutch and / or the brake element. As a result, the inertia torque input to the belt type continuously variable transmission can be reduced. Therefore, even if the vehicle is suddenly braked during the idling stop control while the vehicle is traveling forward, belt slippage of the belt type continuously variable transmission can be suppressed or prevented.

  The second aspect of the invention is the vehicle control apparatus according to the first aspect of the invention, wherein the vehicle has a mechanical oil pump that is driven to rotate by the engine, and a discharge flow rate of the mechanical oil pump. An electric oil pump having a small discharge flow rate is provided. During the idling stop control, the belt of the belt-type continuously variable transmission is clamped by hydraulic oil with a hydraulic pressure discharged from the electric oil pump as a base pressure. Pressure is generated and the lock-up clutch and / or the brake element is engaged. In this way, the belt slip of the belt-type continuously variable transmission can be appropriately suppressed or prevented by the hydraulic pressure discharged from the electric oil pump during the idling stop control.

  According to a third aspect of the present invention, in the vehicle control device according to the first or second aspect of the present invention, it is determined that the traveling path of the vehicle is a low μ road during the execution of the idling stop control. In this case, a predetermined hydraulic pressure is applied to the lock-up clutch and / or the brake element, which is engaged when the vehicle is suddenly braked so that no torque capacity is generated. In this way, the responsiveness when the lockup clutch and / or the brake element is engaged when the vehicle is suddenly braked is improved.

  According to a fourth aspect of the present invention, in the vehicle control device according to any one of the first to third aspects of the invention, the idling stop control releases the clutch element together with the stop of the engine. If the vehicle is suddenly braked during the idling stop control, the clutch element is engaged together with engaging at least one of the lock-up clutch and the brake element. There is to match. In this way, the rotation of the rotary inertia body on the input side of the belt type continuously variable transmission can be appropriately stopped in accordance with the sudden braking of the vehicle. Alternatively, when the vehicle is suddenly braked, an inertia torque due to the rotary inertia body on the input side of the belt-type continuously variable transmission is appropriately assigned to the lockup clutch and / or the brake element.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the schematic structure of the vehicle to which this invention is applied, and is a figure explaining the principal part of the control function and various control systems for various control in a vehicle. 1 is a diagram illustrating a schematic configuration of a hydraulic system that controls operations related to a continuously variable transmission, a lock-up clutch, a forward clutch, and a reverse brake provided in a vehicle. FIG. FIG. 7 is a flowchart for explaining a control operation for suppressing or preventing belt slippage of the continuously variable transmission even if the vehicle is suddenly braked during execution of the eco-run control during deceleration, that is, a main part of the control operation of the electronic control unit. .

  In the present invention, for example, the belt-type continuously variable transmission preferably includes an input having a fixed sheave, a movable sheave, and a hydraulic actuator that applies a thrust for changing a groove width between the fixed sheave and the movable sheave. Side pulleys and output side pulleys, and a transmission belt wound between the input side and output side pulleys. A hydraulic control circuit is configured to independently control the operating hydraulic pressure (pulley pressure) supplied to the hydraulic actuator. Alternatively, for example, the hydraulic control circuit is configured so as to generate pulley pressure as a result of controlling the flow rate of hydraulic oil to the hydraulic actuator. By such a hydraulic control circuit, the thrust in the pulley on the input side and the output side is controlled directly or indirectly (as a result), thereby preventing the transmission belt from slipping. Shift control is executed so that the following shift is realized. In this specification, “supplying hydraulic pressure” means “applying hydraulic pressure” or “supplying hydraulic oil controlled to the hydraulic pressure”.

  Preferably, the engine is, for example, a gasoline engine such as an internal combustion engine, a diesel engine, or the like, but an electric motor or the like can be used in combination with the engine as a driving force source.

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

  FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, and also illustrates a control function for various controls in the vehicle 10 and a main part of a control system. In FIG. 1, a vehicle 10 includes an engine 12 as a driving power source for traveling, a torque converter 14 as a fluid transmission device, a forward / reverse switching device 16, a belt-type continuously variable transmission 18 (hereinafter referred to as a continuously variable transmission 18). ), A reduction gear device 20, a differential gear device 22, left and right drive wheels 24, and the like. In the vehicle 10, the power output from the engine 12 is supplied to the left and right drive wheels 24 through the torque converter 14, the forward / reverse switching device 16, the continuously variable transmission 18, the reduction gear device 20, the differential gear device 22, and the like. Is transmitted to.

  The torque converter 14 includes a pump impeller 14p connected to the engine 12 and a turbine impeller 14t connected to the forward / reverse switching device 16 via a turbine shaft 26, and transmits power through a fluid. The torque converter 14 is provided with a known lock-up clutch LU (hereinafter referred to as a clutch LU) that can directly connect between the pump impeller 14p and the turbine impeller 14t (that is, between input and output rotating members of the torque converter 14). It has been. As the operation state of the clutch LU, for example, the so-called lock-up release (lock-up off) in which the clutch LU is released, the so-called lock-up slip state (slip state) in which the clutch LU is half-engaged (slip operation) with a slip. And a so-called lock-up state (engaged state, lock-up on) in which the clutch LU is completely engaged. When the clutch LU is locked up and off, the torque converter 14 can obtain a torque amplifying action. Further, when the clutch LU is locked up, the pump impeller 14p and the turbine impeller 14t are integrally rotated, and the power of the engine 12 is directly transmitted to the forward / reverse switching device 16 side. Further, when the clutch LU is operated to slip, when the vehicle 10 is driven (powered on), the turbine shaft 26 is rotated following the crankshaft of the engine 12 with a predetermined slip amount, while the vehicle is not driven (powered). When off, the crankshaft of the engine 12 is rotated following the turbine shaft 26 with a predetermined slip amount. A mechanical oil pump 28 is connected to the pump impeller 14p.

  The forward / reverse switching device 16 is mainly configured by a forward clutch C1, a reverse brake B1, and a double pinion planetary gear device 16p. The turbine shaft 26 of the torque converter 14 is integrally connected to the sun gear 16s of the planetary gear device 16p, and the input shaft 30 of the continuously variable transmission 18 is integrally connected to the carrier 16c of the planetary gear device 16p. The carrier 16c and the sun gear 16s are selectively connected via the forward clutch C1, and when the carrier 16c and the sun gear 16s are connected, the planetary gear device 16p is rotated integrally. That is, the forward clutch C1 is a clutch element that selectively rotates the planetary gear device 16p integrally. The ring gear 16r of the planetary gear device 16p is selectively fixed to a housing 32 as a non-rotating member via a reverse brake B1. In other words, the reverse brake B1 is a brake element that selectively couples one rotation element (ring gear 16r) of the rotation elements (sun gear 16s, carrier 16c, ring gear 16r) of the planetary gear device 16p to the housing 32. The forward clutch C1 and the reverse brake B1 are known hydraulic friction engagement devices.

  In the forward / reverse switching device 16 configured as described above, when the forward clutch C1 is engaged and the reverse brake B1 is released, the turbine shaft 26 is directly connected to the input shaft 30, and the forward power transmission path is Established (achieved). When the reverse brake B1 is engaged and the forward clutch C1 is released, the forward / reverse switching device 16 establishes the reverse power transmission path, and the input shaft 30 is reverse to the turbine shaft 26. Rotated in the direction. When both the forward clutch C1 and the reverse brake B1 are released, the forward / reverse switching device 16 is set to a neutral state (power transmission cut-off state) in which power transmission is cut off.

  The continuously variable transmission 18 is an input side member provided on the input shaft 30 and an effective output side member provided on the input side pulley (primary pulley, primary sheave) 34 having a variable effective diameter and the output shaft 36. An output-side pulley (secondary pulley, secondary sheave) 38 having a variable diameter, and a transmission belt 40 wound between the input-side and output-side pulleys 34, 38; A part of the power transmission path between the drive wheels 24 is configured, and power is transmitted via frictional forces between the input and output pulleys 34 and 38 and the transmission belt 40.

  The primary pulley 34 is a fixed sheave 34a as an input-side fixed rotating body fixed to the input shaft 30, and an input-side movable rotation provided so as not to rotate relative to the input shaft 30 and to move in the axial direction. The input side thrust (primary thrust) Win (= primary pressure Pin × pressure receiving area) in the primary pulley 34 for changing the movable sheave 34b as a body and the V groove width between the fixed and movable sheaves 34a and 34b. An input-side hydraulic actuator (hydraulic cylinder) 34c is provided. The secondary pulley 38 has a fixed sheave 38a as an output side fixed rotating body fixed to the output shaft 36, and an output side provided so as not to be rotatable relative to the output shaft 36 and movable in the axial direction. A movable sheave 38b as a movable rotating body and an output-side thrust (secondary thrust) Wout (= secondary pressure Pout × pressure receiving area) in the secondary pulley 38 for changing the V groove width between the fixed and movable sheaves 38a and 38b. ) And an output side hydraulic actuator 38c.

  Then, a primary pressure Pin, which is a working hydraulic pressure supplied to the input-side hydraulic actuator 34c, and a secondary pressure Pout, which is a working hydraulic pressure supplied to the output-side hydraulic actuator 38c, are respectively adjusted by a hydraulic control circuit 72 (see FIG. 2). By controlling the pressure, the primary thrust Win and the secondary thrust Wout are controlled. As a result, the V-groove widths of the pulleys 34 and 38 on the input side and the output side are changed to change the engagement diameter (effective diameter) of the transmission belt 40, and the transmission ratio (gear ratio) γ (= input shaft rotational speed Nin / The output shaft rotational speed Nout) is continuously changed, and the frictional force (belt clamping pressure) between the input side and output side pulleys 34 and 38 and the transmission belt 40 so that the transmission belt 40 does not slip. Is controlled. In this way, by controlling the primary thrust Win and the secondary thrust Wout, the actual speed ratio γ is set to the target speed ratio γtgt while preventing the transmission belt 40 from slipping.

  In addition, the vehicle 10 is provided with an electronic control device 50 including a control device for the vehicle 10 that executes idling stop control, which will be described later, for example. The electronic control unit 50 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control unit 50 is configured to execute output control of the engine 12, shift control of the continuously variable transmission 18, belt clamping pressure control, and the like, and for engine control, the continuously variable transmission 18 as necessary. It is configured separately for hydraulic control. Further, the electronic control unit 50 includes detection values detected by various sensors (for example, the rotational speed sensors 52, 54, 56, 58, the accelerator opening sensor 60, the brake operation amount sensor 62, etc.) provided in the vehicle 10. Various input signals (for example, engine rotational speed Ne, turbine rotational speed Nt, input shaft rotational speed Nin, output shaft rotational speed Nout corresponding to vehicle speed V, accelerator opening θacc, driving for operating a known wheel brake device. A brake operation amount Qbra, which is an operation amount of a brake operation member operated by a person, is supplied. Further, the electronic control device 50 outputs various output signals (for example, an engine output control command signal Se for controlling the output of the engine 12) to each device (for example, the engine 12, the hydraulic control circuit 72, etc.) provided in the vehicle 10. CVT hydraulic control command signal Sccvt for hydraulic control related to the shift of the step transmission 18, etc., engagement hydraulic control command signal Sc for hydraulic control related to the engagement operation of the clutch LU, forward clutch C1, and reverse brake B1, etc. ) Is supplied.

  FIG. 2 is a diagram illustrating a schematic configuration of a hydraulic system 70 that controls operations related to the continuously variable transmission 18, the clutch LU, the forward clutch C 1, and the reverse brake B 1 provided in the vehicle 10. In FIG. 2, the hydraulic system 70 includes a mechanical oil pump 28 and an electric oil pump 74 in addition to the hydraulic control circuit 72.

  The mechanical oil pump 28 is mechanically connected to the engine 12, and is rotationally driven by the engine 12 to control the speed change of the continuously variable transmission 18 or to reduce the belt clamping pressure in the continuously variable transmission 18. The original pressure of the hydraulic pressure for generating, switching the power transmission path in the forward / reverse switching device 16, switching the operating state of the clutch LU, and supplying lubricating oil to each part of the power transmission path of the vehicle 10. The oil pressure is generated (discharged). The electric oil pump 74 is arranged in parallel with the mechanical oil pump 28, and is driven to rotate by the electric motor 76, so that the above-described operation is performed regardless of the rotation state of the engine 12 (for example, when the rotation of the engine 12 is stopped). It is possible to generate (discharge) a hydraulic pressure that is a source pressure of the hydraulic pressure. The mechanical oil pump 28 cannot discharge hydraulic oil when the engine 12 is automatically stopped, for example, in automatic stop / restart control (eco-run control) of the engine 12 described later. For this reason, the electric oil pump 74 is operated at the time of automatic engine stop in the eco-run control which is executed, for example, while the vehicle 10 is decelerating or stopped. As described above, the electric oil pump 74 is exclusively used temporarily as an alternative to the mechanical oil pump 28. For example, the rated maximum discharge flow rate is smaller than the discharge flow rate of the mechanical oil pump. Thus, downsizing is achieved.

  The mechanical oil pump 28 and the electric oil pump 74 suck up the working oil returned to the oil pan 78 provided in the lower part of the housing 32 (transmission case) from a common suction port (strainer) 80, and discharge oil. Discharge to the paths 82 and 84. The discharge oil passage 82 is directly connected, and the discharge oil passage 84 is connected to an oil passage (for example, a line through which the line pressure PL flows) in the hydraulic control circuit 72 via a check valve 86 provided in the hydraulic control circuit 72. It is connected to the pressure oil passage 88). The check valve 86 is provided between the discharge oil passage 82 and the discharge oil passage 84 and prevents the hydraulic pressure output from the mechanical oil pump 28 from flowing into the discharge oil passage 84 side.

  The hydraulic control circuit 72 includes a regulator valve 90 that regulates the line pressure PL using the hydraulic pressure discharged from the mechanical oil pump 28 and / or the electric oil pump 74 as a source pressure, and the continuously variable transmission 18 using the line pressure PL as a source pressure. CVT hydraulic control system 92 for controlling the speed change operation and belt clamping pressure, LU hydraulic control system 94 for controlling the engagement / release operation of the clutch LU using the line pressure PL as a source pressure, and the forward clutch C1 using the line pressure PL as a source pressure And a C1 / B1 hydraulic control system 96 for controlling the disengagement operation of the reverse brake B1.

  For example, the CVT hydraulic control system 92 uses a control valve that regulates a primary pressure Pin that is an operating hydraulic pressure supplied to the hydraulic actuator 34c, an electromagnetic valve that operates the control valve, and a secondary pressure Pout that is an operating hydraulic pressure supplied to the hydraulic actuator 38c. A control valve for regulating pressure and a solenoid valve for operating the control valve are provided. Accordingly, the CVT hydraulic control system 92 can supply the hydraulic pressure to the hydraulic actuators 34c and 38c using the hydraulic pressure discharged from the oil pumps 28 and 74 as a source pressure.

  The LU hydraulic control system 94 includes, for example, a switching valve for switching the operating state of the clutch LU, a control valve for adjusting a lock-up clutch pressure (LU clutch pressure) Plu which is an operating hydraulic pressure supplied to the clutch LU, the switching valve and the control One or more solenoid valves for operating the valve are provided. Therefore, the LU hydraulic pressure control system 94 can supply the operating hydraulic pressure to the clutch LU using the hydraulic pressure discharged from the oil pumps 28 and 74 as a source pressure.

  The C1 / B1 hydraulic control system 96 is, for example, an electromagnetic valve that regulates and outputs a C1 clutch pressure Pc1, which is an operating hydraulic pressure supplied to the forward clutch C1, and a B1 brake pressure, which is an operating hydraulic pressure supplied to the reverse brake B1. An electromagnetic valve that regulates and outputs Pb1 is provided. Therefore, the C1 / B1 hydraulic control system 96 can supply the operating hydraulic pressure to the forward clutch C1 and the reverse brake B1 using the hydraulic pressure discharged from the oil pumps 28 and 74 as a source pressure.

  Returning to FIG. 1, the electronic control unit 50 according to the present embodiment is different from the start / stop of the engine 12 by a user operation such as an ignition key or an ignition switch, for example, when the vehicle 10 temporarily stops at an intersection or the like. When traveling forward (for example, decelerating) at the vehicle speed, the engine 12 is automatically paused regardless of user operation in order to improve fuel efficiency, reduce exhaust gas, reduce noise, etc. Thereafter, automatic stop / restart control (eco-run control, idling stop control) of the engine 12 for automatically restarting the engine 12 is executed. Therefore, the electronic control unit 50 functionally includes an eco-run control means for performing eco-run control, that is, an eco-run control unit 64.

  For example, when a predetermined engine stop condition (idling stop start condition) is satisfied, the eco-run control unit 64 executes fuel cut control or the like to temporarily stop the engine 12. At this time, the eco-run control unit 64 drives the electric motor 76 to rotate the electric oil pump 74 and output the hydraulic pressure, and supplies the hydraulic pressure to the hydraulic control circuit 72. On the other hand, the eco-run control unit 64 rotates (cranks) the engine 12 with a starter (not shown) when a predetermined engine restart condition is established, and in conjunction with the cranking, The engine 12 is restarted by executing opening / closing control, fuel supply control, and ignition timing control. Further, after the engine 12 is restarted (for example, after the engine rotation speed Ne has increased to a predetermined rotation speed or higher so that it can be determined that the engine 12 has completely exploded (autonomous rotation)), the eco-run control unit 64 increases. A), the drive of the electric oil pump 74 is stopped. Thereby, when the engine 12 is stopped, the hydraulic pressure based on the electric oil pump 74 is supplied to the hydraulic actuators 34c, 38c and the forward clutch C1.

  The predetermined engine stop condition is, for example, that the shift position (shift range) is any one of “P”, “N”, and “D” positions (range) and the accelerator opening Acc is determined to be zero. The vehicle speed is determined to be zero and the vehicle is stopped (or the vehicle speed V is determined to be equal to or lower than the predetermined eco-run permission vehicle speed). Further, when the shift position is the “D” position, a condition that the wheel brake is on (brake on) is added as a predetermined engine stop condition. On the other hand, the predetermined engine restart condition is satisfied when, for example, the predetermined engine stop condition is not satisfied after the predetermined engine stop condition is satisfied.

  By the way, when the eco-run control by the eco-run control unit 64 is being executed while the vehicle 10 is traveling forward, there is a possibility that the driver may perform an abrupt deceleration operation that rapidly decelerates the vehicle 10. In such a rapid deceleration operation, the rotational speed from the driving wheel 24 to the transmission belt 40 is suddenly reduced, and the rotational inertial body on the input shaft 30 (that is, the rotational inertial body connected to the input shaft 30) For example, a large inertia torque due to the input shaft 30 itself, the turbine impeller 14t, the planetary gear unit 16p, the primary pulley 34, and the like) is easily input to the continuously variable transmission 18. During the execution of the eco-run control, the pressure is switched to the hydraulic pressure supply by the electric oil pump 74, so that the belt clamping pressure is lower than that during engine operation, and the input inertia torque is inputted to the torque capacity of the continuously variable transmission 18 (belt clamping pressure). ) And belt slippage may occur. This leads to the difficulty of executing the eco-run control from a higher vehicle speed range, and it becomes difficult to obtain the fuel efficiency improvement effect by the eco-run control.

  In view of this, the electronic control unit 50 according to the present embodiment is configured such that when the vehicle 10 is suddenly braked during execution of the eco-run control while the vehicle 10 is traveling forward (for example, when the vehicle 10 is suddenly braked or the driving wheel 24 is For example, when the rotational speed suddenly decreases, at least one of the clutch LU and the reverse brake B1 is engaged. This is because the rotation of the rotary inertia body is forcibly reduced or stopped in accordance with the sudden braking of the vehicle 10 so that the generation of inertia torque by the rotary inertia body on the input shaft 30 is suppressed or prevented, or This is because the inertia torque caused by the rotating inertial body is shared by the clutch LU and / or the reverse brake B1 when the vehicle 10 is suddenly braked. For example, if the clutch LU is engaged during forward traveling with sudden braking (that is, with the turbine shaft 26 (turbine impeller 14t) being directly connected to the input shaft 30 by engagement of the forward clutch C1), The rotation of the rotary inertia body on the input shaft 30 can be forcibly reduced or stopped in accordance with the sudden braking by the inertia of the engine 12 whose rotation has been reduced or stopped. To the clutch LU. Further, if the reverse brake B1 is engaged during forward travel with sudden braking (that is, the planetary gear device 16p is integrally rotated by engagement of the forward clutch C1), the non-rotating member is obtained. By connecting the planetary gear device 16p to the housing 32, the rotation of the rotating inertial body on the input shaft 30 can be forcibly stopped in accordance with the sudden braking, or the inertia torque by the rotating inertial body accompanying the sudden braking. Is shared by the reverse brake B1.

  Further, in a sudden deceleration operation while traveling on a low μ road, the braking (reduction in rotation) of the wheels tends to be sudden. Therefore, the hydraulic pressure may be supplied to the clutch LU and / or the reverse brake B1 in advance in preparation for a sudden deceleration operation while traveling on a low μ road. Therefore, the electronic control device 50 according to the present embodiment is executing the eco-run control in order to improve the response when the clutch LU and / or the reverse brake B1 is engaged when the vehicle 10 is suddenly braked. When it is determined that the travel path of the vehicle 10 is a low μ road, torque capacity is generated for the clutch LU and / or the reverse brake B1 that is engaged when the vehicle 10 is suddenly braked. Supply a certain level of hydraulic pressure. This predetermined hydraulic pressure is determined and stored experimentally or in advance as a hydraulic pressure that can quickly generate torque capacity if the supply hydraulic pressure is increased, for example, for each clutch LU and reverse brake B1 (that is, predetermined hydraulic pressure is determined in advance). I) The hydraulic pressure value just before the torque capacity is generated.

  More specifically, the electronic control unit 50 further includes a traveling state determination unit, that is, a traveling state determination unit 66, and a clutch hydraulic pressure control unit, that is, a clutch hydraulic pressure control unit 68.

  For example, the traveling state determination unit 66 determines whether the traveling path of the vehicle 10 is a low μ road. For example, the traveling state determination unit 66 uses the rotational speed of each wheel detected by a wheel speed sensor (not shown) to determine whether the vehicle 10 has a rotational speed difference between the front and rear wheels that is equal to or greater than a predetermined rotational speed difference. It is determined whether the traveling road is a low μ road. Alternatively, the traveling state determination unit 66 determines whether or not the traveling path of the vehicle 10 is a low μ road based on whether or not the changing speed of the rotational speed of the driving wheel 24 is greater than or equal to a predetermined changing speed when the accelerator is on. Determine whether. Alternatively, the traveling state determination unit 66 determines whether the traveling path of the vehicle 10 is a low μ road based on whether or not the speed of change of the rotational speed of any of the wheels is greater than or equal to a predetermined speed of change when the brake is on. Determine whether or not. For example, when the traveling state determination unit 66 determines that the traveling path of the vehicle 10 is a low μ road, the traveling state determination unit 66 switches the low μ road flag from off to on. The predetermined rotational speed difference, the predetermined change speed when the accelerator is on, and the predetermined change speed when the brake is on, for example, each determine that the traveling road is a low μ road at the accelerator opening θacc or the brake operation amount Qbra at that time. This is a predetermined lower limit determination threshold value.

  Further, the traveling state determination unit 66 determines whether or not the eco-run control is being executed while the vehicle 10 is traveling forward (that is, while the accelerator 10 is decelerated), for example, the fuel cut control of the engine 12 by the eco-run control unit 64 or the like. It is determined based on whether or not is executed. For example, when the traveling state determination unit 66 determines that the eco-run control during the deceleration travel (that is, the eco-run control during deceleration) is being performed, the travel state determination unit 66 determines whether the low μ road flag is on or not. It is determined whether the vehicle is traveling on the road.

  The traveling state determination unit 66 determines (detects), for example, whether or not the vehicle 10 is suddenly braked. For example, the traveling state determination unit 66 determines whether or not the vehicle 10 is suddenly braked based on whether or not the brake operation amount Qbra is equal to or greater than a predetermined operation amount and the change speed of the brake operation amount Qbra is equal to or greater than the predetermined operation amount change speed. It is determined whether or not. The predetermined operation amount and the predetermined operation amount changing speed are, for example, predetermined lower limit determination threshold values for determining that the braking operation by the driver is an abrupt operation.

  The clutch hydraulic pressure control unit 68 is engaged, for example, when the traveling state determination unit 66 determines that the eco-run control during deceleration is being performed and the vehicle is traveling on a low μ road when the traveling state determination unit 66 determines a sudden braking. A command for supplying a predetermined hydraulic pressure to the LU and / or the reverse brake B 1 is output to the hydraulic control circuit 72. The clutch hydraulic pressure control unit 68 supplies the predetermined hydraulic pressure when, for example, the traveling state determination unit 66 is executing the deceleration eco-run control, is traveling on a low μ road, and the vehicle 10 is determined to be suddenly braked. A command for engaging the clutch LU and / or the reverse brake B 1 is output to the hydraulic control circuit 72.

  FIG. 3 shows a control part for controlling or preventing belt slippage of the continuously variable transmission 18 even if the vehicle 10 is suddenly braked during the execution of the control operation of the electronic control unit 50, that is, the deceleration eco-run control. It is a flowchart explaining the operation, and is repeatedly executed with a very short cycle time of, for example, about several milliseconds to several tens of milliseconds.

  In FIG. 3, first, in step (hereinafter, step is omitted) S10 corresponding to the traveling state determination unit 66, it is determined whether, for example, deceleration-time eco-run control is being executed. If the determination in S10 is negative, this routine is terminated. If the determination is positive, it is determined in S20 corresponding to the traveling state determination unit 66, for example, whether the vehicle is traveling on a low μ road. If the determination in S20 is negative, this routine is terminated. If the determination is affirmative, in S30 corresponding to the clutch hydraulic pressure control unit 68, for example, the clutch LU and / or reverse drive engaged in S50 described later. A command to supply (fill) a predetermined hydraulic pressure to the brake B1 is output to the hydraulic control circuit 72. Next, in S40 corresponding to the traveling state determination unit 66, for example, it is determined whether or not the vehicle 10 is suddenly braked. If the determination in S40 is negative, this routine is terminated. If the determination is positive, in S50 corresponding to the clutch hydraulic pressure control unit 68, for example, the clutch LU and / or the predetermined hydraulic pressure charged in S30. A command to engage the reverse brake B 1 is output to the hydraulic control circuit 72.

  As described above, according to the present embodiment, the rotation of the rotary inertia body on the input side of the continuously variable transmission 18 (that is, the rotary inertia body on the input shaft 30) is forcibly stopped in accordance with the sudden braking of the vehicle 10. Or, when the vehicle 10 is suddenly braked, the inertia torque due to the rotary inertia body on the input side of the continuously variable transmission 18 is shared by the clutch LU and / or the reverse brake B1. As a result, the inertia torque input to the continuously variable transmission 18 can be reduced. Therefore, even if the vehicle 10 is suddenly braked during the execution of the eco-run control during deceleration, the belt slip of the continuously variable transmission 18 can be suppressed or prevented. Further, the vehicle speed V at which the eco-run control at the time of deceleration can be implemented is expanded to a high vehicle speed region, which contributes to further improvement in fuel consumption. When the clutch LU and the reverse brake B1 are engaged, the above-described effects are easily obtained as compared to the case where the clutch LU or the reverse brake B1 is engaged.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, during the eco-run control during deceleration by the eco-run control unit 64, the forward clutch C1 remains engaged, but the engine 12 is stopped (fuel cut) so as to obtain a better fuel efficiency effect. In conjunction with the control, the forward clutch C1 may be released to a neutral state. In this way, when the forward clutch C1 is released together with the stop of the engine 12 during the eco-run control, and the vehicle 10 is suddenly braked during the eco-run control, the clutch LU and / or The forward clutch C1 is engaged in conjunction with engaging the reverse brake B1. In this way, the rotation of the rotary inertia body on the input side of the continuously variable transmission 18 can be appropriately stopped in accordance with the sudden braking of the vehicle 10, or the continuously variable transmission 18 can be The inertia torque due to the rotational inertial body on the input side can be appropriately assigned to the clutch LU and / or the reverse brake B1.

  In the above-described embodiment, the traveling state determination unit 66 determines whether or not the vehicle 10 is suddenly braked based on the brake operation amount Qbra. However, the present invention is not limited to this determination method. For example, various determination methods such as determining whether or not the vehicle 10 is suddenly braked based on whether or not the speed of change of the rotational speed of the wheel with respect to the brake operation amount Qbra at that time exceeds a determination threshold value ( Detection method) is used.

  Further, in the flowchart of FIG. 3 in the above-described embodiment, each step can be appropriately changed within a range that does not interfere with the present invention, for example, the present invention can be established even if S20 and S30 are not provided.

  In the above-described embodiment, for example, instead of the torque converter 14, another fluid transmission device such as a fluid coupling having no torque amplification action may be used. Further, although the planetary gear device 16p of the forward / reverse switching device 16 is a double pinion type, it may be a single pinion type planetary gear device.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

10: Vehicle 12: Engine 14: Torque converter (fluid transmission)
16: Forward / reverse switching device 16p: Planetary gear device 16s: Sun gear (rotating element)
16c: Carrier (rotating element)
16r: Ring gear (rotating element)
18: Belt type continuously variable transmission 24: Drive wheel 32: Housing (non-rotating member)
50: Electronic control device (control device)
LU: lock-up clutch C1: forward clutch (clutch element)
B1: Reverse brake (brake element)

Claims (1)

An engine, a fluid transmission device having a lock-up clutch, a planetary gear device, a clutch element that selectively rotates the planetary gear device integrally, and a rotating element of the planetary gear device selectively. A brake element connected to a non-rotating member, and a forward power transmission path is established by engaging the clutch element and releasing the brake element, while moving backward by releasing the clutch element and engaging the brake element. A vehicle comprising: a forward / reverse switching device that establishes a power transmission path for a vehicle; and a belt-type continuously variable transmission that forms part of a power transmission path between the forward / backward switching device and a drive wheel. A vehicle control device capable of executing idling stop control for stopping the engine during forward traveling,
When the vehicle is suddenly braked during the idling stop control, at least one of the lockup clutch and the brake element is engaged.

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