JP7006427B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device.

Patent Document 1 describes a vehicle including a power transmission device in which a continuously variable transmission and a gear mechanism are arranged in parallel between an engine and a drive wheel. The hydraulic pressure control device of the vehicle is via a linear solenoid valve that supplies hydraulic pressure to a clutch arranged in a power transmission path via a stepless transmission, an accumulator that stores hydraulic pressure to the linear solenoid valve, and a gear mechanism. It is provided with a linear solenoid valve that supplies hydraulic pressure to a synchro mechanism arranged in a power transmission path, a mechanical oil pump and an electric oil pump that are hydraulic pressure supply sources, and a pressure regulating valve that regulates oil supplied to a torque converter.

Japanese Unexamined Patent Publication No. 2017-007369

However, in the configuration described in Patent Document 1, when the synchro mechanism is engaged under the condition that the flow rate balance of oil is severe, the line pressure drops and the lockup capacity cannot be secured. If the lockup capacity cannot be secured, the lockup engaged state cannot be maintained and the lockup clutch cannot be guaranteed to transition from the engaged state to the released state. Therefore, the lock clutch is quickly engaged in the engaged state during sudden deceleration. It was not possible to transition to the released state from, and there was a risk of engine stall.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle control device capable of avoiding the occurrence of engine stall even under conditions where the flow rate balance of oil is severe. do.

The present invention has a power transmission device in which a stepless transmission and a gear mechanism are arranged in parallel between the engine and the drive wheels, a clutch arranged in a power transmission path via the stepless transmission, and a gear. A synchro mechanism arranged in the power transmission path via the mechanism, a first linear solenoid valve that supplies hydraulic pressure to the clutch, an accumulator that stores hydraulic pressure supplied to the first linear solenoid valve, and a synchro mechanism that supplies hydraulic pressure. A vehicle control device including a second linear solenoid valve, an oil pump that is a hydraulic pressure supply source, and a torque converter with a lockup clutch that supplies oil regulated by the pressure regulating valve. During the engagement transient control of the synchro mechanism, the engagement prohibition control means for prohibiting the start of engagement of the lockup clutch and the lockup clutch are released when the vehicle speed is less than a predetermined value when the synchro mechanism is engaged. It is characterized by comprising an engagement start control means for starting the engagement of the synchro mechanism after the clutch is engaged.

In the present invention, the engagement start of the lockup clutch is prohibited during the engagement transient control of the synchro mechanism, and when the vehicle speed is less than a predetermined value when the synchro mechanism is engaged, after the lockup clutch is released. The engagement of the synchro mechanism is started. As a result, the lockup capacity can be secured even under conditions where the flow rate balance of the oil is severe, so that it is possible to avoid an engine stall during sudden deceleration or the like.

FIG. 1 is a skeleton diagram schematically showing a target vehicle in the embodiment. FIG. 2 is a functional block diagram schematically showing a control device. FIG. 3 is a hydraulic circuit diagram showing an example of a hydraulic control device. FIG. 4 is a flowchart showing a sequence flow of LU control and synchro control.

Hereinafter, the vehicle control device according to the embodiment of the present invention will be specifically described with reference to the drawings. The present invention is not limited to the embodiments described below.

[1. vehicle]
FIG. 1 is a skeleton diagram schematically showing a target vehicle in the embodiment. The vehicle Ve includes an engine 1 as a power source. The power output from the engine 1 is a torque converter 2, an input shaft 3, a forward / backward switching mechanism 4, a belt-type continuously variable transmission (hereinafter referred to as "CVT") 5, a gear mechanism 6, and an output shaft, which are fluid transmission devices. 7. It is transmitted to the drive wheel 11 via the counter gear mechanism 8, the differential gear 9, and the axle 10. Further, on the downstream side of the CVT 5, a second clutch C2 is provided as a clutch for disconnecting the engine 1 from the drive wheels 11. By releasing the second clutch C2, torque cannot be transmitted between the CVT 5 and the output shaft 7, and the CVT 5 in addition to the engine 1 is disconnected from the drive wheels 11.

Specifically, the torque converter 2 is arranged between the pump impeller 2a connected to the engine 1, the turbine runner 2b arranged to face the pump impeller 2a, and the pump impeller 2a and the turbine runner 2b. It is provided with a stator 2c. The inside of the torque converter 2 is filled with a working fluid (oil). The pump impeller 2a rotates integrally with the crankshaft 1a of the engine 1. The input shaft 3 is connected to the turbine runner 2b so as to rotate integrally. The torque converter 2 is a torque converter with a lockup clutch including a lockup clutch 21. In the engaged state of the lockup clutch 21 (lockup engaged state), the pump impeller 2a and the turbine runner 2b rotate integrally. In the released state of the lockup clutch 21 (lockup released state), the power output from the engine 1 is transmitted to the turbine runner 2b via the working fluid. The stator 2c is held by a fixed portion such as a case via a one-way clutch.

Further, a mechanical oil pump (MOP) 41 is connected to the pump impeller 2a via a transmission mechanism such as a belt mechanism. Since the mechanical oil pump 41 is connected to the crankshaft 1a via the pump impeller 2a, it is driven by the engine 1. The mechanical oil pump 41 and the pump impeller 2a may be configured to rotate integrally.

The input shaft 3 is connected to the forward / backward switching mechanism 4. When the engine torque is transmitted to the drive wheels 11, the forward / backward switching mechanism 4 switches the direction of the torque acting on the drive wheels 11 between the forward direction and the reverse direction. The forward / backward switching mechanism 4 is composed of a differential mechanism, and in the example shown in FIG. 1, it is configured by a double pinion type planetary gear mechanism. The forward / backward switching mechanism 4 meshes with the sun gear 4S, the ring gear 4R arranged concentrically with respect to the sun gear 4S, the first pinion gear 4P _{1 meshing with the sun gear 4S, the first pinion gear 4P 1 and} the ring gear 4R. The second pinion gear 4P ₂ is provided with a carrier 4C that holds the pinion gears 4P ₁ and 4P ₂ so that they can rotate and revolve. The drive gear 61 of the gear mechanism 6 is connected to the sun gear 4S so as to rotate integrally. The input shaft 3 is connected to the carrier 4C so as to rotate integrally. Further, a first clutch C1 that selectively and integrally rotates the sun gear 4S and the carrier 4C is provided. By engaging the first clutch C1, the entire forward / backward switching mechanism 4 rotates integrally. Further, a brake B1 for selectively fixing the ring gear 4R so as not to rotate is provided. The first clutch C1 and the brake B1 are hydraulic.

For example, when the first clutch C1 is engaged and the brake B1 is released, the sun gear 4S and the carrier 4C rotate integrally. That is, the input shaft 3 and the drive gear 61 rotate integrally. Further, when the first clutch C1 is released and the brake B1 is engaged, the sun gear 4S and the carrier 4C rotate in opposite directions. That is, the input shaft 3 and the drive gear 61 rotate in opposite directions.

In the vehicle Ve, the CVT 5 which is a stepless speed change unit and the gear mechanism 6 which is a stepped speed change unit are provided in parallel. As a power transmission path between the input shaft 3 and the output shaft 7, a power transmission path via the CVT 5 (hereinafter referred to as "first path") and a power transmission path via the gear mechanism 6 (hereinafter referred to as "second path"). And are formed in parallel.

The CVT 5 includes a primary pulley 51 that rotates integrally with the input shaft 3, a secondary pulley 52 that rotates integrally with the secondary shaft 54, and a belt 53 wound around a V groove formed in the pair of pulleys 51 and 52. There is. The input shaft 3 becomes a primary shaft. Since the winding diameter of the belt 53 is changed by changing the V-groove width of each of the pulleys 51 and 52, the gear ratio γ of the CVT 5 can be continuously changed. The gear ratio γ of the CVT 5 continuously changes within the range from the maximum gear ratio γ _max (maximum Low) to the minimum gear ratio γ _min (maximum High).

The primary pulley 51 includes a fixed sheave 51a integrated with the input shaft 3, a movable sheave 51b that can move in the axial direction on the input shaft 3, and a primary hydraulic cylinder 51c that applies thrust to the movable sheave 51b. There is. The sheave surface of the fixed sheave 51a and the sheave surface of the movable sheave 51b face each other to form a V-groove of the primary pulley 51. The primary hydraulic cylinder 51c is arranged on the back surface side of the movable sheave 51b. The hydraulic pressure (primary pressure) Pin _in the primary hydraulic cylinder 51c generates a thrust that moves the movable sheave 51b toward the fixed sheave 51a.

The secondary pulley 52 includes a fixed sheave 52a integrated with the secondary shaft 54, a movable sheave 52b that can move in the axial direction on the secondary shaft 54, and a secondary hydraulic cylinder 52c that applies thrust to the movable sheave 52b. There is. The sheave surface of the fixed sheave 52a and the sheave surface of the movable sheave 52b face each other to form a V groove of the secondary pulley 52. The secondary hydraulic cylinder 52c is arranged on the back side of the movable sheave 52b. The hydraulic pressure (secondary pressure) P _out in the secondary hydraulic cylinder 52c generates a thrust that moves the movable sheave 52b toward the fixed sheave 52a.

The second clutch C2 is provided between the secondary shaft 54 and the output shaft 7, and can selectively disconnect the CVT 5 from the output shaft 7. For example, when the second clutch C2 is engaged, the CVT 5 and the output shaft 7 are connected so as to be able to transmit power, and the secondary shaft 54 and the output shaft 7 rotate integrally. When the second clutch C2 is released, torque cannot be transmitted between the secondary shaft 54 and the output shaft 7, and the engine 1 and the CVT 5 are disconnected from the drive wheels 11. The second clutch C2 is hydraulic. The engagement elements of the second clutch C2 are configured to be frictionally engaged with each other by a hydraulic actuator.

The output gear 7a and the driven gear 63 are attached to the output shaft 7 so as to rotate integrally. The output gear 7a meshes with the counter driven gear 8a of the counter gear mechanism 8 which is a reduction mechanism. The counter drive gear 8b of the counter gear mechanism 8 meshes with the ring gear 9a of the differential gear 9. The left and right drive wheels 11 and 11 are connected to the differential gear 9 via the left and right axles 10 and 10.

The gear mechanism 6 includes a drive gear 61 that rotates integrally with the sun gear 4S of the forward / backward switching mechanism 4, a counter gear mechanism 62, and a driven gear 63 that rotates integrally with the output shaft 7. The gear mechanism 6 is a reduction mechanism, and the gear ratio (gear ratio) of the gear mechanism 6 is set to a predetermined value larger than the maximum gear ratio γ _max of the CVT 5. The gear ratio of the gear mechanism 6 is a fixed gear ratio. The vehicle Ve is configured to transmit torque from the engine 1 to the drive wheels 11 via the gear mechanism 6 at the time of starting. The gear mechanism 6 functions as a starting gear.

The drive gear 61 meshes with the counter driven gear 62a of the counter gear mechanism 62. The counter gear mechanism 62 includes a counter driven gear 62a, a counter shaft 62b, and a counter drive gear 62c that meshes with the driven gear 63. A counter driven gear 62a is attached to the counter shaft 62b so as to rotate integrally. The counter shaft 62b is arranged in parallel with the input shaft 3 and the output shaft 7. The counter drive gear 62c is configured to be rotatable relative to the counter shaft 62b. Further, a meshing type engaging device (hereinafter referred to as “synchro mechanism”) S1 for selectively and integrally rotating the counter shaft 62b and the counter drive gear 62c is provided.

The synchronization mechanism S1 includes a pair of meshing engaging elements 64a and 64b and a sleeve 64c that can be moved in the axial direction. The first engaging element 64a is a hub spline-fitted to the counter shaft 62b. The first engaging element 64a and the counter shaft 62b rotate integrally. The second engaging element 64b is connected to the counter drive gear 62c so as to rotate integrally. That is, the second engaging element 64b rotates relative to the counter shaft 62b. The spline teeth formed on the inner peripheral surface of the sleeve 64c mesh with the spline teeth formed on the outer peripheral surfaces of the engaging elements 64a and 64b, so that the synchro mechanism S1 is in an engaged state. By engaging the synchro mechanism S1, the drive gear 61 and the driven gear 63 (second path) are connected so as to be able to transmit torque. When the engagement between the second engaging element 64b and the sleeve 64c is released, the synchronization mechanism S1 is released. By releasing the synchro mechanism S1, the torque transmission between the drive gear 61 and the driven gear 63 (second path) is cut off so as not to be able to transmit torque. Further, the synchronization mechanism S1 is a hydraulic type, and the sleeve 64c is moved in the axial direction by the hydraulic actuator. The synchronization mechanism S1 is a rotation-synchronous engagement device configured by a synchromesh.

[2. Control device]
FIG. 2 is a functional block diagram schematically showing the control device of the embodiment. The control device of the embodiment is composed of an electronic control device (hereinafter referred to as "ECU") 100 that controls the vehicle Ve. The ECU 100 is mainly composed of a microcomputer, performs a calculation using input data and data stored in advance, and outputs the calculation result as a command signal.

Signals from various sensors 31 to 38 are input to the ECU 100. The vehicle speed sensor 31 detects the vehicle speed. The input shaft rotation speed sensor 32 detects the rotation speed (input shaft rotation speed) N _in of the input shaft 3. Since the input shaft 3 and the turbine runner 2b rotate integrally, the input shaft rotation speed sensor 32 detects the rotation speed (turbine rotation speed) _Nt of the turbine runner 2b. The input shaft rotation speed N _in and the turbine rotation speed N _t match. The first output shaft rotation speed sensor 33 detects the rotation speed (first output shaft rotation speed) N _out 1 of the secondary shaft 54. The second output shaft rotation speed sensor 34 _detects the rotation speed (second output shaft rotation speed) N out 2 of the output shaft 7. Before the second clutch C2 (upstream side) is the first output shaft rotation speed N _out1 , and after the second clutch C2 (downstream side) is the second output shaft rotation speed N _out2 . The engine rotation speed sensor 35 detects the rotation speed (engine rotation speed) _Ne of the crankshaft 1a. The accelerator opening sensor 36 detects an operation amount of an accelerator pedal (not shown). The brake stroke sensor 37 detects the operation amount of the brake pedal (not shown). The shift position sensor 38 detects the position of a shift lever (not shown). Regarding the position of the shift lever, the drive position is represented by "D", the reverse position is represented by "R", the parking position is represented by "P", and the neutral position is represented by "N". Further, the ECU 100 can calculate the gear ratio γ (= N _in / N _{out 1} ) of the CVT 5 by dividing the input shaft rotation speed N _in by the first output shaft rotation speed N _out 1.

The ECU 100 includes a lockup control unit 101 that performs LU control (lockup control), and a clutch control unit 102 that controls the states of the engagement devices C1, C2, B1, and S1.

The lock-up control unit 101 performs control (lock-up control) for switching the state of the lock-up clutch 21 between the engaged state and the released state. When the lockup control unit 101 performs lockup control (LU control), the second pressure regulating valve 212 (shown in FIG. 3) described later is controlled, and the hydraulic pressure supplied to the torque converter 2 (second described later). The line pressure _PL2 ) is controlled to a predetermined pressure. Further, the lockup control unit 101 implements LU control for prohibiting the lockup clutch 21 from switching from the released state to the engaged state when a predetermined condition is satisfied.

The clutch control unit 102 performs synchro control for switching the synchro mechanism S1 between the engaged state and the disengaged state. As the synchro control, the clutch control unit 102 controls the synchro mechanism S1 to transition from the released state to the engaged state (synchro engagement transient control) and the synchro mechanism S1 to transition from the engaged state to the released state (synchro release). Control) and.

The ECU 100 outputs a command signal to the engine 1 to control the fuel supply amount, the intake air amount, the fuel injection, the ignition timing, and the like. Further, the ECU 100 outputs a hydraulic pressure command signal to the hydraulic pressure control device 200 to control the operation of the lockup clutch 21, the shifting operation of the CVT 5, and the operation of each engaging device such as the first clutch C1. The hydraulic pressure control device 200 supplies hydraulic pressure to the hydraulic cylinders 51c and 52c of the CVT 5 and the hydraulic actuators of the engaging devices C1, C2, B1 and S1. By controlling the hydraulic control device 200, the ECU 100 controls to switch the power transmission path between the first path and the second path, and controls to switch between the engaged state and the released state of the lockup clutch 21 (LU control). , CVT5 shift control, control to switch to various driving modes, and the like are executed.

The driving mode is divided into a normal driving mode and a free run. The normal driving mode includes three driving modes: start, medium speed and high speed. At the time of starting, the first clutch C1 and the synchronization mechanism S1 are engaged, and the second clutch C2 and the brake B1 are released. The power transmission path at the time of starting is set to the second path via the gear mechanism 6. When the vehicle speed rises to some extent after starting, the traveling mode shifts from starting to medium speed by performing grip change control in which the first clutch C1 is released and the second clutch C2 is engaged. At medium speed, the second clutch C2 and the synchronization mechanism S1 are engaged, and the first clutch C1 and the brake B1 are released. The power transmission path at medium speed is set to the first path via CVT5. That is, at the time of transition from starting to medium speed, the power transmission path is switched from the second path to the first path. Further, the gripping control between the first clutch C1 and the second clutch C2 is a clutch-to-clutch control that gradually changes the transmission torque capacity. When the vehicle speed further increases during the medium speed traveling, the synchronization mechanism S1 is released and the traveling mode shifts from the medium speed to the high speed. At high speeds, the second clutch C2 is engaged, and the first clutch C1, the brake B1 and the synchronization mechanism S1 are released. At the time of transition from medium speed to high speed, the route is not switched and the power transmission path remains the first path.

At the time of reverse movement (R), the power transmission path is set to the second path via the gear mechanism 6 by engaging the brake B1 with the synchro mechanism S1 and releasing the first clutch C1 and the second clutch C2. .. When the shift position is "N" or "P", the synchronization mechanism S1 is engaged, and the first clutch C1, the second clutch C2, and the brake B1 are released.

Free runs also include medium speed and high speed. At the free-run medium speed, the synchronization mechanism S1 is engaged, and the first clutch C1, the second clutch C2, and the brake B1 are released. At free-run high speed, the first clutch C1, the second clutch C2, the brake B1 and the synchro mechanism S1 are released. The power transmission path during free run is set to the first path. For example, the transition from normal driving to free run includes a transition from a normal medium speed to a free run medium speed and a transition from a normal high speed to a free run high speed. By releasing the second clutch C2 while traveling at the normal medium speed, the vehicle shifts to the free run medium speed. By releasing the second clutch C2 while traveling at a normal high speed, the vehicle shifts to a free-run high speed. Further, when returning from the free run to the normal running, the second clutch C2 is engaged. By engaging the second clutch C2 at the free run medium speed, the normal medium speed is restored. By engaging the second clutch C2 at the free run high speed, the normal high speed is restored.

[3. Hydraulic circuit]
FIG. 3 is a hydraulic circuit diagram showing an example of the hydraulic control device 200. The hydraulic pressure control device 200 includes a mechanical oil pump 41 driven by an engine (Eng) 1 and an electric oil pump 43 driven by an electric motor (M) 42 as a hydraulic pressure supply source. A battery (not shown) is electrically connected to the electric motor 42. Each of the pumps 41 and 43 is a pumping device, and sucks the oil stored in the oil pan and pumps it to the first oil passage 201. The oil discharged from the electric oil pump 43 is supplied to the first oil passage 201 via the second oil passage 202. The first oil passage 201 and the second oil passage 202 are connected via a check valve. The check valve closes when the oil pressure in the first oil passage 201 is higher than the oil pressure in the second oil passage 202. The check valve opens when the oil pressure in the first oil passage 201 is lower than the oil pressure in the second oil passage 202. For example, during the free run, the engine 1 is stopped and the mechanical oil pump 41 cannot be driven. Therefore, the pressure oil is supplied into the first oil passage 201 by driving the electric oil pump 43.

The hydraulic control device 200 regulates the pressure of the first oil passage 201 to the first line pressure _PL1 and the oil discharged from the first pressure regulating valve 211 to the second line pressure _PL2 . The second pressure regulating valve 212, the first pressure reducing valve (modulator valve) 213 that regulates the pressure to a predetermined modulator pressure PM using the first line pressure _PL1 as the original pressure, and the primary pressure _P using the first line pressure _PL1 as the original pressure. It is provided with a second pressure reducing valve (shift ratio control valve) 214 for adjusting the _in pressure and a third pressure reducing valve (pinching pressure control valve) 215 for adjusting the secondary pressure P _out with the first line pressure _PL1 as the original pressure. The first pressure regulating valve 211 is controlled based on the control pressure output from a linear solenoid valve (not shown) so as to generate the first line pressure _PL1 according to the traveling state. Further, the oil regulated to the second line pressure _PL2 by the second pressure regulating valve 212 is supplied to the torque converter 2. The oil discharged from the second pressure regulating valve 212 is supplied to a lubrication system such as a meshing portion between gears. The second pressure regulating valve 212 corresponds to the pressure regulating valve constituting the present invention.

A plurality of linear solenoid valves SL1, SL2, SLG, SLP, and SLS are connected to the first pressure reducing valve 213 via the third oil passage 203. The linear solenoid valves SL1, SL2, SLG, SLP, and SLS are independently excited, de-excited, and current controlled by the ECU 100 to regulate the hydraulic pressure according to the hydraulic pressure command signal.

The linear solenoid valve SL1 adjusts the modulator pressure PM to the first clutch pressure _PC1 corresponding to the hydraulic pressure command signal and supplies the modulator pressure PM to the first clutch _C1 . The linear solenoid valve SL2 regulates the modulator pressure PM to the second clutch pressure _PC2 corresponding to the hydraulic pressure command signal and supplies the modulator pressure PM to the second clutch _C2 . The linear solenoid valve SLG adjusts the modulator pressure _{PM to the supply hydraulic pressure P bs corresponding} to the hydraulic pressure command signal, and supplies it to the synchro mechanism S1 and the brake B1. The linear solenoid valve SLG is connected to the synchronization mechanism S1 and the brake B1 via the switching valve 216. The switching valve 216 operates mechanically or electrically to switch the oil passage based on the operation of the shift lever. When the shift lever is in the "D" position, the supply hydraulic pressure P _bs is supplied to the synchronization mechanism S1. When the shift lever is in the "R" position, the supply hydraulic pressure P _bs is supplied to the synchro mechanism S1 and the brake B1. When the shift lever is in the "P" or "N" position, the supply hydraulic pressure P _bs is supplied to the synchronization mechanism S1. Further, the third oil passage 203 is provided with an accumulator 217 for accumulating hydraulic pressure. The accumulator 217 can store the hydraulic pressure supplied to the linear solenoid valves SL1 and SL2. The linear solenoid valve SL2 corresponds to the first linear solenoid valve constituting the present invention, and the linear solenoid valve SLG corresponds to the second linear solenoid valve constituting the present invention.

The linear solenoid valve _SLP regulates the signal pressure _PSLP with the modulator pressure PM as the original pressure, and outputs the signal pressure _PSLP to the second pressure reducing valve 214. The linear solenoid valve _SLS regulates the signal pressure _PSLS with the modulator pressure PM as the original pressure, and outputs the signal pressure _PSLS to the third pressure reducing valve 215.

A primary hydraulic cylinder 51c is connected to the second pressure reducing valve 214 via the fourth oil passage 204. The second pressure reducing valve 214 is a valve for controlling the gear ratio γ of the CVT 5, and controls the amount of oil (hydraulic pressure) supplied to the primary hydraulic cylinder 51c. The second pressure reducing valve 214 adjusts the primary pressure Pin with the first line pressure _PL1 as the original pressure, and supplies the pressure to the primary hydraulic cylinder _51c . The second pressure reducing valve 214 regulates the primary pressure Pin based on the signal pressure _PSLP input from the linear solenoid valve _SLP . The ECU 100 _adjusts the primary pressure Pin by controlling the hydraulic pressure command signal output to the linear solenoid valve SLP. By changing the primary pressure Pin, the V- _groove width of the primary pulley 51 changes. The ECU 100 controls the gear ratio γ of the CVT 5 by controlling the primary pressure _Pin .

A secondary hydraulic cylinder 52c is connected to the third pressure reducing valve 215 via the fifth oil passage 205. The third pressure reducing valve 215 is a valve that controls the belt pinching pressure, and controls the amount of oil (hydraulic pressure) supplied to the secondary hydraulic cylinder 52c. The third pressure reducing valve 215 adjusts the secondary pressure P _out with the first line pressure _PL1 as the original pressure, and supplies the pressure to the secondary hydraulic cylinder 52c. The third pressure reducing valve 215 regulates the secondary pressure P _out based on the signal pressure PSLS input from the linear solenoid valve _SLS . The ECU 100 adjusts the secondary pressure P _out by controlling the hydraulic pressure command signal output to the linear solenoid valve SLS. By changing the secondary pressure P _out , the belt pinching pressure of the CVT 5 changes. The ECU 100 controls the pinching pressure of the CVT 5 by controlling the secondary pressure P _out .

[4. Control flow]
FIG. 4 is a flowchart showing a sequence flow of lockup control and synchro control. The control shown in FIG. 4 is performed by the ECU 100. In addition, "LU" shown in FIG. 4 means the lockup clutch 21.

First, it is determined whether or not the lockup clutch 21 is in the released state (step S101).

When the lockup clutch 21 is in the released state and is positively determined in step S101 (step S101: Yes), it is determined whether or not the synchro engagement transient control is in progress (step S102).

When a negative determination is made in step S102 because the synchro engagement transient control is not in progress (step S102: No), normal control is performed (step S103). When step S103 is performed, the line pressure (second line pressure _PL2 ) can be secured and the lockup capacity can be secured, so that the engagement of the lockup clutch 21 can be started freely. Therefore, in step S103, it is not necessary to perform control in consideration of the fact that the oil flow rate balance is severe.

When it is positively determined in step S102 because the synchro engagement transient control is in progress (step S102: Yes), the engagement start of the lockup clutch 21 is prohibited (step S104). When step S104 is performed, the lockup clutch 21 is engaged in consideration of the fact that the line pressure (second line pressure _PL2 ) drops due to the synchro engagement transient control and the lockup capacity cannot be secured. It is forbidden to start.

Further, when a negative determination is made in step S101 because the lockup clutch 21 is not in the released state (step S101: No), it is determined whether or not to engage the synchronization mechanism S1 (step S105). In step S105, it is determined whether or not there is an engagement request for the synchronization mechanism S1.

If a negative determination is made in step S105 by not engaging the synchronization mechanism S1 (step S105: No), this control routine returns to step S101.

When a positive determination is made in step S105 by engaging the synchronization mechanism S1 (step S105: Yes), it is determined whether or not the vehicle speed is equal to or higher than a predetermined value (step S106).

When a negative determination is made in step S106 because the vehicle speed is less than a predetermined value (step S106: No), a release request for the lockup clutch 21 is made (step S107). In step S107, the lockup clutch 21 is released. When step S107 is performed, first, the lockup clutch 21 is first considered in consideration of the fact that the line pressure (second line pressure _PL2 ) drops due to the synchro engagement transient control and the lockup capacity cannot be secured. To release.

Then, after releasing the lockup clutch 21, the engagement of the synchronization mechanism S1 is started (step S108). In step S108, control for transitioning the synchro mechanism S1 from the released state to the engaged state (synchro engagement transient control) is started during the lockup release.

When a positive determination is made in step S106 because the vehicle speed is equal to or higher than a predetermined value (step S106: Yes), normal control is performed (step S109). When performing step S109, the engagement start of the synchronization mechanism S1 is free. That is, if the vehicle speed is equal to or higher than a predetermined value, the line pressure (second line pressure _PL2 ) can be secured and the lockup capacity can be secured, so that there is no restriction on the start of synchro engagement. Further, in step S109, it is not necessary to perform control in consideration of the fact that the oil flow rate balance is severe.

As described above, according to the embodiment, if the lockup engaged state is maintained under severe oil flow conditions or the transition from the lockup engaged state to the lockup released state cannot be guaranteed, the lockup is performed. The engagement of the lockup clutch 21 is started after the engagement of the clutch 21 is prohibited or the lockup clutch 21 is released. As a result, the lockup capacity can be secured even under conditions where the flow rate balance of the oil is severe, so that it is possible to avoid an engine stall during sudden deceleration or the like. Then, it is possible to achieve both avoidance of engine stall and smooth start.

1 engine 2 torque converter 5 continuously variable transmission (CVT)
6 Gear mechanism 21 Lock-up clutch 100 Electronic control unit (ECU)
C1 1st clutch C2 2nd clutch S1 Sync mechanism Ve vehicle

Claims (1)

A power transmission device in which a continuously variable transmission and a gear mechanism are arranged in parallel between the engine and the drive wheels,
A clutch arranged in a power transmission path via the continuously variable transmission, and
A synchro mechanism arranged in the power transmission path via the gear mechanism, and
The first linear solenoid valve that supplies hydraulic pressure to the clutch,
An accumulator that stores the hydraulic pressure supplied to the first linear solenoid valve, and
A second linear solenoid valve that supplies hydraulic pressure to the synchro mechanism,
The oil pump, which is the source of the hydraulic pressure,
A vehicle control device equipped with a torque converter with a lockup clutch to which oil regulated by a pressure regulating valve is supplied.
During the engagement transient control of the synchro mechanism, the engagement prohibition control means for prohibiting the engagement start of the lockup clutch and the engagement prohibition control means.
When the vehicle speed is less than a predetermined value when the synchro mechanism is engaged, the engagement start control means for starting the engagement of the synchro mechanism after releasing the lockup clutch is provided. Vehicle control device.

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