JP2018017388A - Control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vehicle which can be IDS-restored while suppressing a belt slide even if air intrudes into a secondary pulley or a primary pulley while suppressing the intrusion of air into an oil chamber of the secondary pulley at a stop of an engine caused by IDS control.SOLUTION: In abutment control, in a period that the generation of the hydraulic pressure of an oil pump is eliminated after a stop of an engine by IDS control, concretely, in a period until a vehicle is stopped after the stop of the engine by the IDS control, an output of a downshift indication is continued. When the generation of the hydraulic pressure of the oil pump remains, there is a possibility that a movable sheave of the primary pulley is displaced. Since the output of the downshift indication is continued until the generation of the hydraulic pressure of the oil pump 5 is eliminated, it is avoided that the movable sheave is displaced from a position for constituting a physical maximum gear change ratio (lowest).SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control device used in a vehicle equipped with a belt type continuously variable transmission.

  In recent years, IDS control has been adopted for vehicles using an engine as a drive source for the purpose of improving fuel consumption. In a vehicle employing IDS control, for example, when the vehicle speed drops below a predetermined IDS start vehicle speed due to a driver's brake operation, the engine is automatically stopped (idling stop). Thereafter, when the driver releases the brake operation, the engine is automatically restarted.

  In vehicles adopting IDS control, there is a vehicle type equipped with a belt-type continuously variable transmission (CVT). In a continuously variable transmission, when the vehicle stops from a deceleration state, it is necessary to return the gear ratio to the maximum gear ratio (lowest) before the vehicle stops, so oil is discharged from the oil chamber of the primary pulley. Is done. When the engine is stopped by the IDS control, in order to keep the oil in the oil chamber (prevent air entry), the closing control is performed so that the oil entering and exiting each oil chamber of the secondary pulley and the primary pulley is not drained.

  Since the oil is confined in the oil chamber of the primary pulley by the closing control, an effect of preventing air from entering the oil chamber of the primary pulley can be expected. However, in the continuously variable transmission having the characteristic that the thrust of the movable sheave of the primary pulley is larger than the thrust of the movable sheave of the secondary pulley during the closing control, when the flow rate of the oil pump becomes 0 due to the engine stop, the secondary pulley Due to the thrust by the provided bias spring, the volume of the oil chamber of the secondary pulley increases, and there is a concern that air may enter the oil chamber of the secondary pulley. In a continuously variable transmission configured such that the seal between the movable sheave of the primary pulley and the cylinder is not well sealed with a seal, oil leaks from the gap between the seals, and the air to the oil chambers of the primary pulley and the secondary pulley Cannot prevent entry.

  When air flows into the oil chamber of the secondary pulley or the primary pulley, the rise of the hydraulic pressure of the secondary pulley or the primary pulley is delayed at the time of IDS recovery by restarting the engine, and the performance (time lag, shock) at the time of IDS recovery deteriorates. In addition, slippage between the pulley and the belt (belt slip) may occur due to insufficient thrust.

JP 2013-181408 A

  The object of the present invention is to prevent the air from entering the oil chamber of the secondary pulley while the engine is stopped by the IDS control, and to return to the IDS while suppressing the belt slip even when the air enters the secondary pulley or the primary pulley. It is to provide a vehicle control device.

  In order to achieve the above object, a vehicle control device according to the present invention is a control device used in a vehicle equipped with an engine, a belt-type continuously variable transmission, and an oil pump that supplies clamping pressure. An IDS control means for executing IDS control for stopping the engine in response to establishment of the IDS start condition and restarting the engine in response to establishment of a predetermined IDS return condition during the stop; When the output of a downshift instruction for returning the transmission gear ratio to the maximum gear ratio is started and the engine is stopped by the IDS control with the gear ratio returning to the maximum gear ratio, at least the oil pressure generated by the oil pump is lost. Downshift instruction output means for continuing output of the downshift instruction until.

  According to this configuration, in the IDS control, the engine is stopped when the IDS start condition is satisfied, and the engine is restarted when the IDS return condition is satisfied while the engine is stopped.

  When the vehicle is decelerated from the deceleration state, a downshift instruction for returning the speed ratio of the continuously variable transmission to the maximum speed ratio is output. In response to the output of the downshift instruction, the hydraulic pressure of the primary pulley is drained. The secondary pulley of the continuously variable transmission is usually provided with a spring that urges the movable sheave toward the side closer to the fixed sheave. When the hydraulic pressure of the primary pulley is drained, the thrust of the movable sheave of the secondary pulley due to the bias of the spring is transmitted to the movable sheave of the primary pulley via the belt, and the movable sheave of the primary pulley is displaced away from the fixed sheave. . When the movable sheave of the primary pulley comes into contact with the stopper, further displacement of the movable sheave is prevented, and the position of the movable sheave is physically held at the position that constitutes the maximum gear ratio (physical lowest position). .

  When the engine is stopped by the IDS control with the speed ratio returned to the maximum speed ratio, the output of the downshift instruction is continued until the oil pressure generated by the oil pump is exhausted. The movable sheave of the primary pulley may be displaced while the oil pressure generated by the oil pump remains. By continuing to output the downshift instruction until the oil pressure generated by the oil pump is exhausted, it is possible to suppress the displacement of the movable sheave from the physical lowest position. As a result, when the engine is stopped by IDS control, an upshift caused by the oil flowing into the oil chamber of the primary pulley can be suppressed, and after the oil pressure generated by the oil pump is reduced, the gear ratio is increased by the bias spring thrust of the secondary pulley. By returning to the maximum gear ratio side, there is no opportunity to increase the volume of the oil chamber of the secondary pulley, and the air entering the oil chamber of the secondary pulley due to the increase in volume can be suppressed.

  Even when the IDS return condition is satisfied and the engine is restarted, it is preferable that a downshift instruction is output and the hydraulic pressure of the primary pulley is drained. Since the oil pressure of the primary pulley is drained, the engine is restarted and the oil pressure generated by the oil pump rises, and then the oil pressure of the secondary pulley always rises before the oil pressure of the primary pulley. Since the movable sheave of the primary pulley is in contact with the stopper at the physical lowest position, when the hydraulic pressure of the secondary pulley rises, the spring force of the secondary pulley and the thrust by the hydraulic pressure are transferred via the belt to the movable sheave of the primary pulley. The reaction force from the stopper acts as a thrust on the belt from the movable sheave of the primary pulley.

  Therefore, even when air enters the secondary pulley or primary pulley, the clutch engagement target pressure at which belt slip does not occur can be calculated by measuring the oil pressure of the secondary pulley, so that belt slippage at the time of IDS return is suppressed. can do.

  When the oil pump is a mechanical oil pump driven by engine power, it is preferable that the output of the downshift instruction is continued from the stop of the engine by the IDS control to the stop of the vehicle.

  When the vehicle is stopped, the number of revolutions of the pulley becomes 0, so that the displacement of the movable sheave of the primary pulley is suppressed, and even when the downshift instruction is finished, the air entering the oil chamber of the secondary pulley is suppressed. can do.

  When the hydraulic pressure is generated even during IDS control by an electric oil pump or the like after the downshift instruction is finished, it is preferable that the downshift instruction is output again when the vehicle rolls again.

  Upshift due to oil flowing into the primary pulley's oil chamber when the vehicle is not stopped is suppressed, so that even if the electric oil pump is subsequently stopped, air entry into the oil chamber of the secondary pulley is suppressed. can do.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a volume change arises in the oil chamber of a secondary pulley during the engine stop by IDS control, and can enter into the oil chamber of the secondary pulley by the volume change. Further, the speed ratio (pulley ratio) is maintained at the maximum speed ratio. As a result, when returning to the IDS by restarting the engine, the secondary pulley or the primary pulley is inflated while suppressing the deterioration of the performance (time lag, shock) at the time of returning the IDS due to the delay in the rise of the hydraulic pressure of the secondary pulley. Even if it occurs, the occurrence of belt slip due to insufficient thrust can be suppressed.

It is a figure which shows the structure of the principal part of the vehicle by which the control apparatus which concerns on one Embodiment of this invention is mounted. It is a skeleton figure which shows the structure of the drive system of a vehicle. It is a figure which shows the time change of the state of the vehicle speed at the time of IDS control, a pulley ratio (speed ratio), an engine speed, and a downshift instruction | indication.

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

<Vehicle configuration>
FIG. 1 is a diagram illustrating a configuration of a main part of a vehicle 1 on which a control device according to an embodiment of the present invention is mounted.

  The vehicle 1 is an automobile that uses the engine 2 as a drive source. The output of the engine 2 is transmitted to the left and right drive wheels of the vehicle 1 via a torque converter 3 and a continuously variable transmission (CVT) 4.

  The engine 2 is provided with an electronic throttle valve for adjusting the amount of intake air into the combustion chamber of the engine 2, an injector (fuel injection device) that injects fuel into the intake air, and an ignition plug that generates electric discharge in the combustion chamber. It has been. The engine 2 is also provided with a starter for starting the engine 2.

  The vehicle 1 includes a plurality of ECUs (Electronic Control Units) having a configuration including a CPU, a ROM, a RAM, and the like. The plurality of ECUs include an engine ECU 11 and a CVTECU 12. Each ECU is connected so that bidirectional communication by a CAN (Controller Area Network) communication protocol is possible.

  An accelerator sensor 21 and an engine speed sensor 22 are connected to the engine ECU 11.

  The accelerator sensor 21 outputs a detection signal corresponding to the operation amount of the accelerator pedal operated by the driver. Based on the detection signal input from the accelerator sensor 21, the engine ECU 11 sets the ratio of the operation amount to the maximum operation amount of the accelerator pedal, that is, 0% when the accelerator pedal is not depressed, and the accelerator pedal is depressed to the maximum. The accelerator opening, which is a percentage with the time taken as 100%, is calculated.

  The engine speed sensor 22 outputs a pulse signal synchronized with the rotation of the engine 2 (rotation of the crankshaft) as a detection signal. The engine ECU 11 converts the frequency of the pulse signal input from the engine speed sensor 22 into the speed of the engine 2 (engine speed).

  The engine ECU 11 is provided in the engine 2 for starting, stopping and adjusting the output of the engine 2 based on information obtained from detection signals of various sensors and / or various information input from other ECUs. Controls electronic throttle valves, injectors, and spark plugs.

  A primary rotational speed sensor 23, a secondary rotational speed sensor 24, a hydraulic pressure sensor 25, and the like are connected to the CVT ECU 12.

  The primary rotational speed sensor 23 outputs, for example, a pulse signal synchronized with the rotation of the primary shaft 51 (see FIG. 2) of the continuously variable transmission 4 as a detection signal. The CVTECU 12 converts the frequency of the pulse signal input from the primary rotational speed sensor 23 into the rotational speed (primary rotational speed) of the primary shaft 51.

  For example, the secondary rotational speed sensor 24 outputs a pulse signal synchronized with the rotation of the secondary shaft 52 (see FIG. 2) of the continuously variable transmission 4 as a detection signal. The CVTECU 12 converts the frequency of the pulse signal input from the secondary rotational speed sensor 24 into the rotational speed (secondary rotational speed) of the secondary shaft 52.

  The hydraulic pressure sensor 25 outputs a detection signal corresponding to the hydraulic pressure acting on the movable sheave 66 (see FIG. 2) of the secondary pulley 54 of the continuously variable transmission 4. The CVTECU 12 acquires the hydraulic pressure acting on the movable sheave 66 from the detection signal of the hydraulic sensor 25.

  The CVTECU 12 controls each part of the continuously variable transmission 4 for the shift control of the continuously variable transmission 4 based on information obtained from detection signals of various sensors and / or various information input from other ECUs. Various valves included in a hydraulic circuit 26 for supplying hydraulic pressure are controlled.

<Configuration of drive system>
FIG. 2 is a skeleton diagram showing the configuration of the drive system of the vehicle 1.

  The torque converter 3 includes a pump impeller 31, a turbine runner 32, and a lockup clutch 33. An output shaft (E / G output shaft) of the engine 2 is connected to the pump impeller 31, and the pump impeller 31 is provided so as to be integrally rotatable around the same rotation axis as the E / G output shaft. ing. The turbine runner 32 is provided to be rotatable about the same rotation axis as the pump impeller 31. The lockup clutch 33 is provided to directly connect / separate the pump impeller 31 and the turbine runner 32. When the lockup clutch 33 is engaged, the pump impeller 31 and the turbine runner 32 are directly connected, and when the lockup clutch 33 is released, the pump impeller 31 and the turbine runner 32 are separated.

  When the E / G output shaft is rotated in a state where the lockup clutch 33 is released, the pump impeller 31 rotates. When the pump impeller 31 rotates, an oil flow from the pump impeller 31 toward the turbine runner 32 is generated. This oil flow is received by the turbine runner 32 and the turbine runner 32 rotates. At this time, the amplifying action of the torque converter 3 occurs, and the turbine runner 32 generates a power larger than the power (torque) of the E / G output shaft.

  When the lockup clutch 33 is engaged, when the E / G output shaft is rotated, the E / G output shaft, the pump impeller 31 and the turbine runner 32 are rotated together.

  An oil pump 5 is provided between the torque converter 3 and the continuously variable transmission 4. The oil pump 5 is a mechanical oil pump, and the pump shaft is disposed so that the rotational axis of the pump impeller 31 coincides with the pump impeller 31 and is coupled to the pump impeller 31 so as not to be relatively rotatable. Accordingly, when the pump impeller 31 is rotated by the power of the engine 2, the pump shaft of the oil pump 5 is rotated and oil is discharged from the oil pump 5.

  The continuously variable transmission 4 transmits the power input from the torque converter 3 to the differential gear 6. The continuously variable transmission 4 includes an input shaft 41, an output shaft 42, a belt transmission mechanism 43, and a forward / reverse switching mechanism 44.

  The input shaft 41 is connected to the turbine runner 32 of the torque converter 3 and is provided so as to be integrally rotatable about the same rotation axis as the turbine runner 32.

  The output shaft 42 is disposed in parallel with the input shaft 41. An output gear 45 is supported on the output shaft 42 so as not to be relatively rotatable.

  The belt transmission mechanism 43 includes a primary shaft 51 and a secondary shaft 52. The primary shaft 51 and the secondary shaft 52 are disposed on the same axis as the input shaft 41 and the output shaft 42, respectively.

  The belt transmission mechanism 43 has a configuration in which an endless belt 55 is wound around a primary pulley 53 supported by a primary shaft 51 and a secondary pulley 54 supported by a secondary shaft 52.

  The primary pulley 53 is disposed so as to face the fixed sheave 61 fixed to the primary shaft 51 with the belt 55 sandwiched between the fixed sheave 61 and is supported by the primary shaft 51 so as to be movable in the axial direction but not to be relatively rotatable. 62. A piston 63 fixed to the primary shaft 51 is provided on the opposite side of the movable sheave 62 from the fixed sheave 61, and a piston chamber (oil chamber) 64 is formed between the movable sheave 62 and the piston 63. Yes.

  The secondary pulley 54 is disposed to face the fixed sheave 65 fixed to the secondary shaft 52 with the belt 55 sandwiched between the fixed sheave 65 and is supported by the secondary shaft 52 so as to be movable in the axial direction but not to be relatively rotatable. A movable sheave 66 is provided. A piston 67 fixed to the secondary shaft 52 is provided on the opposite side of the movable sheave 66 from the fixed sheave 65, and a piston chamber 68 is formed between the movable sheave 66 and the piston 67.

  A bias spring 69 for applying an initial clamping pressure (initial thrust) to the belt 55 is interposed between the movable sheave 66 and the piston 67. Due to the elastic force of the bias spring 69, the movable sheave 66 and the piston 67 are urged in a direction away from each other.

  The forward / reverse switching mechanism 44 is interposed between the input shaft 41 and the primary shaft 51 of the belt transmission mechanism 43. The forward / reverse switching mechanism 44 includes a planetary gear mechanism 71, a reverse clutch C1, and a forward brake B1.

  The planetary gear mechanism 71 includes a carrier 72, a sun gear 73, and a ring gear 74.

  The carrier 72 is fitted on the input shaft 41 so as to be relatively rotatable. The carrier 72 rotatably supports a plurality of pinion gears 75. The plurality of pinion gears 75 are arranged on the circumference.

  The sun gear 73 is supported by the input shaft 41 so as not to rotate relative to the input shaft 41, and is disposed in a space surrounded by the plurality of pinion gears 75. The gear teeth of the sun gear 73 mesh with the gear teeth of each pinion gear 75.

  The ring gear 74 is provided such that its rotational axis coincides with the axis of the primary shaft 51. A primary shaft 51 of the belt transmission mechanism 43 is connected to the ring gear 74. The gear teeth of the ring gear 74 are formed so as to collectively surround the plurality of pinion gears 75 and mesh with the gear teeth of each pinion gear 75.

  The reverse clutch C1 is switched between an engaged state (on) in which the carrier 72 and the sun gear 73 are directly coupled (coupled so as to be integrally rotatable) and a released state (off) in which the direct coupling is released by hydraulic pressure.

  The forward brake B <b> 1 is provided between the carrier 72 and a transmission case that houses the torque converter 3 and the continuously variable transmission 4, and engages (turns on) to brake the carrier 72 by hydraulic pressure, and rotates the carrier 72. It is switched to an allowable release state (off).

  When the vehicle 1 moves forward, the reverse clutch C1 is released and the forward brake B1 is engaged. When the power of the engine 2 is input to the input shaft 41, the sun gear 73 rotates integrally with the input shaft 41 while the carrier 72 is stationary. Therefore, the rotation of the sun gear 73 is transmitted to the ring gear 74 while being reversed and decelerated. As a result, the ring gear 74 rotates, and the primary shaft 51 and the primary pulley 53 of the belt transmission mechanism 43 rotate together with the ring gear 74. The rotation of the primary pulley 53 is transmitted to the secondary pulley 54 via the belt 55 to rotate the secondary pulley 54 and the secondary shaft 52. Then, the output shaft 42 and the output gear 45 rotate integrally with the secondary shaft 52. The output gear 45 meshes with the differential gear 6 (the input gear of the differential gear 6). When the output gear 45 rotates, the drive shafts 7 and 8 extending left and right from the differential gear 6 rotate and drive wheels (not shown) rotate, so that the vehicle 1 moves forward.

  On the other hand, when the vehicle 1 moves backward, the reverse clutch C1 is engaged and the forward brake B1 is released. When the power of the engine 2 is input to the input shaft 41, the carrier 72 and the sun gear 73 rotate integrally with the input shaft 41. Therefore, the rotation of the sun gear 73 is transmitted to the ring gear 74 without reversing the rotation direction. As a result, the ring gear 74 rotates in the direction opposite to that when the vehicle 1 moves forward, and the primary shaft 51 and the primary pulley 53 of the belt transmission mechanism 43 rotate together with the ring gear 74. The rotation of the primary pulley 53 is transmitted to the secondary pulley 54 via the belt 55 to rotate the secondary pulley 54 and the secondary shaft 52. Then, the output shaft 42 and the output gear 45 rotate integrally with the secondary shaft 52. When the output gear 45 rotates, the drive shafts 7 and 8 extending from the differential gear 6 to the left and right rotate in the opposite direction to the forward movement, and the drive wheels (not shown) rotate, whereby the vehicle 1 moves backward.

<Hydraulic control>
In the continuously variable transmission 4, the oil supply from the hydraulic circuit 26 to the piston chamber 64 of the primary pulley 53 and the piston chamber 68 of the secondary pulley 54 is controlled by the CVTECU 12 so that the gear ratio according to the accelerator opening and the vehicle speed is obtained. (Shift control)

  When the gear ratio is lowered, for example, the flow rate of oil supplied to the piston chamber 64 of the primary pulley 53 is increased. As a result, the movable sheave 62 moves to the fixed sheave 61 side, and the interval (groove width) between the fixed sheave 61 and the movable sheave 62 is reduced. Accordingly, the winding diameter of the belt 55 around the primary pulley 53 is increased, and the interval (groove width) between the fixed sheave 65 and the movable sheave 66 of the secondary pulley 54 is increased. As a result, the pulley ratio between the primary pulley 53 and the secondary pulley 54 becomes small, and the gear ratio becomes small.

  When the gear ratio is increased, the flow rate of oil supplied to the movable sheave 62 of the primary pulley 53 is decreased. Thereby, the thrust of the secondary pulley 54 with respect to the belt 55 becomes larger than the thrust of the primary pulley 53 with respect to the belt 55, the interval between the fixed sheave 65 and the movable sheave 66 of the secondary pulley 54 is reduced, and the fixed sheave 61 and the movable sheave The distance from 62 increases. As a result, the pulley ratio between the primary pulley 53 and the secondary pulley 54 is increased, and the transmission ratio of the continuously variable transmission 4 is increased.

  On the other hand, the clamping pressure between the primary pulley 53 and the secondary pulley 54 needs to be large enough to prevent slippage between the primary pulley 53 and the secondary pulley 54 and the belt 55. Therefore, the hydraulic pressure supplied to the movable sheave 66 of the secondary pulley 54 is controlled so as to obtain a clamping pressure corresponding to the magnitude of the input torque input to the input shaft 41 (clamping pressure control).

  When the vehicle 1 is stopped from the deceleration state, a downshift instruction is output from the CVTECU 12 to return the gear ratio of the continuously variable transmission 4 to the maximum gear ratio. In response to the output of the downshift instruction, the hydraulic pressure is drained from the piston chamber 64 of the primary pulley 53. Since the secondary pulley 54 is provided with the bias spring 69, when the hydraulic pressure is drained from the piston chamber 64 of the primary pulley 53, the thrust of the movable sheave 66 of the secondary pulley 54 due to the biasing of the bias spring 69 passes through the belt 55. Is transmitted to the movable sheave 62 of the primary pulley 53, and the movable sheave 62 of the primary pulley 53 is displaced away from the fixed sheave 61.

  The primary pulley 53 is provided with a stopper S for restricting the displacement of the movable sheave 62 at a fixed position. The fixed position is a position where the physical maximum speed ratio (lowest) of the continuously variable transmission 4 is configured. Thereby, when the drain of the hydraulic pressure from the piston chamber 64 of the primary pulley 53 is continued by the output of the downshift instruction, the movable sheave 62 contacts the stopper S, and further movement of the movable sheave 62 is prevented, A maximum transmission ratio is configured.

<Abutting control>
FIG. 3 is a diagram showing temporal changes in the vehicle speed, pulley ratio (transmission ratio), engine speed, and downshift instruction state during IDS control.

  In the vehicle 1, IDS control (idling stop control) is executed. IDS control is a technique for improving fuel consumption by suppressing idling of the engine 2. As information necessary for the IDS control, information such as a vehicle speed and a brake pedal operation amount is input to the engine ECU 11.

  In the IDS control, when the brake pedal is operated (depressed) while the vehicle 1 is traveling, the engine ECU 11 determines whether or not a predetermined IDS start condition is satisfied. The IDS start condition is, for example, a condition that the vehicle speed is a predetermined idling stop execution vehicle speed (for example, 10 km / h) or less and the brake pedal is operated for a predetermined time or more. While the brake pedal is being operated, the engine ECU 11 determines whether or not the IDS start condition is satisfied at a constant cycle. When the IDS start condition is satisfied, the engine 2 is stopped (idling stop) by the engine ECU 11. After the start of idling stop, the engine ECU 11 determines whether or not a predetermined IDS return condition is satisfied at a constant cycle. The IDS return condition is, for example, a condition that the operation of the brake pedal is released during the idling stop (the driver's foot is released from the brake pedal). When the IDS return condition is satisfied, the engine ECU 11 operates the starter and restarts the engine 2.

  It may be determined whether the IDS start condition is satisfied by an ECU different from engine ECU 11, for example, IDSECU for IDS control. In this case, an IDS request is transmitted from the IDSECU to the engine ECU 11 in response to the establishment of the IDS start condition, and the engine 2 is stopped by the engine ECU 11 in response to the IDS request. Further, the IDSECU determines whether or not the IDS return condition is satisfied. When the IDS return condition is satisfied, an IDS return request is transmitted from the IDSECU to the engine ECU 11, and the engine 2 is restarted by the engine ECU 11 in response to the IDS return request.

  When the vehicle 1 is stopped from the deceleration state, the engine 2 is stopped by the IDS control after the speed ratio returns to the maximum speed ratio. In the conventional control, as indicated by the broken line, a downshift instruction is issued. The output is stopped (time T1).

  On the other hand, in the butting control in the vehicle 1, the engine 2 is stopped by the IDS control until the oil pressure generated by the oil pump 5 disappears, for example, the engine 2 is stopped by the IDS control and the vehicle 1 is stopped. (Time T1-T2), the output of the downshift instruction is continued. The movable sheave 62 of the primary pulley 53 may be displaced while the hydraulic pressure generated by the oil pump 5 remains, especially while the pulley is rotating. The output of the downshift instruction is continued until the oil pressure generated by the oil pump 5 is lost and the vehicle 1 is stopped, so that the movable sheave 62 is displaced from the position constituting the physical maximum gear ratio (lowest). It is suppressed.

  Even when the IDS return condition is satisfied and the engine 2 is restarted, the downshift instruction is output, and the hydraulic pressure of the primary pulley 53 can be drained (time T3). Thus, after the engine 2 is restarted and the generated hydraulic pressure of the oil pump 5 rises, the hydraulic pressure acting on the movable sheave 66 of the secondary pulley 54 is always ahead of the hydraulic pressure acting on the movable sheave 62 of the primary pulley 53. stand up. Since the movable sheave 62 of the primary pulley 53 is in contact with the stopper at the physically lowest position, when the hydraulic pressure of the secondary pulley 54 rises, the spring force of the bias spring 69 of the secondary pulley 54 and the thrust by the hydraulic pressure are applied to the belt. The reaction force from the stopper S acts on the belt 55 from the movable sheave 62 of the primary pulley 53 as a thrust.

<Effect>
As described above, when the engine 2 is stopped by the IDS control after the speed ratio has returned to the maximum speed ratio, the output of the downshift instruction is continued until the hydraulic pressure generated by the oil pump 5 is exhausted. Thereby, it is possible to suppress the displacement of the movable sheave 62 of the primary pulley 53 from the physical lowest position. As a result, it is possible to suppress the volume change from occurring in the piston chamber 68 of the secondary pulley 54 while the engine 2 is stopped by the IDS control, and it is possible to suppress the air entering the piston chamber 68 due to the volume change. Therefore, when the IDS is restored by restarting the engine 2, it is possible to suppress a delay in the rise of the hydraulic pressure in the piston chamber 68 of the secondary pulley 54, and the thrust can be reduced while maintaining the performance (time lag, shock) at the time of IDS restoration. Occurrence of belt slip due to shortage can be suppressed.

  Further, when the IDS return condition is satisfied and the engine 2 is restarted, the downshift instruction is output, so that the hydraulic pressure in the piston chamber 68 of the secondary pulley 54 is changed into the piston chamber 64 of the primary pulley 53. It can be launched before the hydraulic pressure. Since the movable sheave 62 of the primary pulley 53 is in contact with the stopper S, the reaction force from the stopper S is transferred from the movable sheave 62 of the primary pulley 53 to the belt 55 when the hydraulic pressure in the piston chamber 68 of the secondary pulley 54 rises. Acts as a thrust.

  Therefore, even when air enters the piston chamber 68 of the secondary pulley 54 or the piston chamber 64 of the primary pulley 53, the oil pressure obtained from the detection signal of the oil pressure sensor 25 (the oil pressure acting on the movable sheave 66 of the secondary pulley 54). Thus, by calculating the clutch engagement target pressure, it is possible to avoid the occurrence of belt slip due to insufficient thrust of the primary pulley 54 while avoiding belt slip due to insufficient thrust of the secondary pulley 54. As a result, it is possible to satisfactorily suppress the occurrence of belt slip when returning to IDS.

  “Until the oil pressure generated by the oil pump 5 is exhausted” means “when there is no concern that the primary sheave thrust will overwhelm the secondary sheave thrust including the bias spring thrust when the binding (upshift) is instructed”. It is synonymous.

  If the oil pressure generated by the oil pump 5 is lost, a binding (upshift) instruction may be issued even when the vehicle 1 is traveling.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, some or all of the functions of the engine ECU 11 and the transmission ECU 12 may be integrated into one ECU.

  In the above-described embodiment, the continuously variable transmission 4 is taken up. However, the control device according to the present invention is a power split type continuously variable transmission or a low mode with a relatively large speed ratio and a high speed with a relatively small speed ratio. It can also be used for a CVT with a sub-transmission capable of switching between modes. The power split type continuously variable transmission includes a belt-type continuously variable transmission mechanism that continuously changes power by changing a transmission ratio, and a constant transmission mechanism that changes power at a constant transmission ratio. Is a transmission that can be divided into two systems for transmission. When the control device according to the present invention is used for the CVT with a sub-transmission, it is preferable that the output of the downshift instruction is continued until the pulley ratio (speed ratio) returns to the maximum speed ratio.

  Further, the present invention can be applied to a configuration including an electric oil pump instead of the mechanical oil pump 5 or in addition to the oil pump 5.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

1 vehicle 2 engine 4 continuously variable transmission 5 oil pump 11 engine ECU (IDS control means)
12 CVTECU (downshift instruction output means)

Claims (1)

A control device used in a vehicle equipped with an engine, a belt-type continuously variable transmission and an oil pump for supplying clamping pressure,
IDS control means for executing IDS control for stopping the engine in response to establishment of a predetermined IDS start condition and restarting the engine in response to establishment of a predetermined IDS return condition during the stop. When,
When the output of a downshift instruction for returning the transmission gear ratio of the continuously variable transmission to the maximum transmission gear ratio is started and the engine is stopped by the IDS control in a state where the transmission gear ratio has returned to the maximum transmission gear ratio, at least the oil And a downshift instruction output means for continuously outputting the downshift instruction until the generated hydraulic pressure of the pump is exhausted.

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