JP6987444B2 - Vehicle control device - Google Patents

Description

The present invention relates to a control device used for a vehicle that employs IDS (idling stop) control.

In recent years, IDS control has been adopted for vehicles using an engine as a drive source for the purpose of improving fuel efficiency and the like. In a vehicle adopting 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). Then, for example, when the driver releases the brake operation, the engine is automatically restarted.

Among vehicles that adopt IDS control, there are vehicles equipped with an automatic transmission such as a continuously variable transmission (CVT) as a transmission. In this vehicle model, for example, a forward clutch is interposed between the torque converter and the continuously variable transmission, and when the engine is stopped (deceleration IDS) during deceleration running of the vehicle, the forward clutch is released.

Japanese Unexamined Patent Publication No. 2013-181408

When the IDS is restored by restarting the engine, it is necessary to engage the forward clutch in order to transmit the power from the engine to the continuously variable transmission. In a vehicle equipped with only a mechanical oil pump driven by the power of the engine as an oil pump that generates hydraulic pressure in the hydraulic circuit, the hydraulic pressure in the hydraulic circuit drops while the engine is stopped, so the hydraulic pressure when returning to IDS It takes time to rise. Therefore, even if the engine is restarted, the forward clutch does not engage, and there is a concern that the engine speed will rise.

An object of the present invention is to provide a vehicle control device capable of suppressing the engine rotation from rising when the engine is restarted.

In order to achieve the above object, the vehicle control device according to the present invention engages between the engine and the automatic transmission by the differential pressure between the hydraulic pressure in the oil pressure chamber on the engaging side and the hydraulic pressure in the oil pressure chamber on the releasing side. A control device used in vehicles equipped with a torque converter with a lockup clutch that is released and equipped with an engaging element that is hydraulically engaged / disengaged to transmit / disconnect power between the engine and the wheels. Therefore, the IDS control that stops the engine when the predetermined IDS start condition is satisfied and executes the IDS control to restart the engine when the predetermined IDS return condition is satisfied during the stop. When the IDS return condition is satisfied with the means and the engaging element released, the differential pressure adjusting means for reducing the differential pressure between the hydraulic pressure of the engaging side oil chamber and the hydraulic pressure of the releasing side oil chamber to a predetermined value or less. And include.

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.

Further, when the IDS return condition is satisfied, the differential pressure between the oil pressure in the oil chamber on the engaging side and the oil pressure in the oil chamber on the releasing side of the torque converter is set to a predetermined value or less. When the differential pressure between the hydraulic pressure in the engaging side oil chamber and the hydraulic pressure in the releasing side oil chamber is set to a predetermined value or less, the rotation of the pump impeller of the torque converter accompanying the rotation of the engine causes the lockup clutch (lockup piston). Centrifugal hydraulic pressure is generated in the oil in the oil chamber on the engaging side between the pump impeller, and the centrifugal hydraulic pressure presses the lockup clutch against the front cover. This becomes the resistance to the rotation of the pump impeller, and the resistance acts in the drag direction with respect to the rotation of the engine. As a result, it is possible to suppress the engine rotation from rising.

The predetermined value may be zero as long as the lockup clutch operates on the engaging side due to the centrifugal hydraulic pressure generated in the engaging side oil chamber. That is, the differential pressure adjusting means makes the differential pressure between the hydraulic pressure of the engaging side oil chamber and the hydraulic pressure of the releasing side oil chamber zero when the IDS return condition is satisfied while the engaging element is released. It may be a differential pressure means. In this case, "zeroing the differential pressure between the hydraulic pressure of the engaging side oil chamber and the hydraulic pressure of the releasing side oil chamber" means, of course, when the actual hydraulic pressures of the engaging side oil chamber and the releasing side oil chamber match. , The valve that supplies hydraulic pressure to the engaging side oil chamber and the releasing side oil chamber is controlled so that the hydraulic pressure of the engaging side oil chamber and the hydraulic pressure of the releasing side oil chamber match, but their actual oil pressure is in error. Including cases where there is a deviation in the range.

According to the present invention, it is possible to suppress the engine rotation from rising when the engine is restarted.

It is a skeleton diagram which shows the structure of the drive system of a vehicle. It is a block diagram which shows the structure of the control system of a vehicle. It is a figure which shows an example of the time change of the IDS return condition fulfillment / non-satisfaction, zero differential pressure control on / off, engine rotation speed and turbine rotation speed.

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

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

The vehicle 1 is an automobile whose drive source is the engine 2.

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 a spark plug that causes an electric discharge in the combustion chamber. Has been done. Further, the engine 2 is provided with a starter for starting the engine 2. The power of the engine 2 is transmitted to the differential gear 5 via the torque converter 3 and the belt-type continuously variable transmission (CVT) 4, and is transmitted from the differential gear 5 via the left and right drive shafts 6L and 6R. It is transmitted to the left and right drive wheels 7L and 7R, respectively.

The torque converter 3 includes a front cover 51, a pump impeller 52, a turbine runner 53, and a lockup clutch (lockup piston) 54. The crankshaft of the engine 2 is connected to the front cover 51, and the front cover 51 rotates integrally with the crankshaft. The pump impeller 52 is arranged on the side opposite to the engine side with respect to the front cover 51. The pump impeller 52 is provided so as to be rotatable integrally with the front cover 51. The turbine runner 53 is arranged between the front cover 51 and the pump impeller 52, and is rotatably provided about a rotation axis common to the front cover 51. The lockup clutch 54 is arranged between the front cover 51 and the turbine runner 53.

The lockup clutch 54 is a differential pressure between the hydraulic pressure of the release side oil chamber 55 between the lockup clutch 54 and the front cover 51 and the hydraulic pressure of the engagement side oil chamber 56 between the lockup clutch 54 and the pump impeller 52. Engages / disengages with. That is, when the hydraulic pressure of the release side oil chamber 55 is higher than the hydraulic pressure of the engagement side oil chamber 56, the lockup clutch 54 is separated from the front cover 51 due to the differential pressure, and the lockup clutch 54 is released (lockup). Off). When the hydraulic pressure of the engaging side oil chamber 56 is higher than the hydraulic pressure of the releasing side oil chamber 55, the lockup clutch 54 is pressed against the front cover 51 due to the differential pressure, and the lockup clutch 54 is engaged (locked up). On).

When the E / G output shaft is rotated in the lock-up / off state, the pump impeller 52 rotates. When the pump impeller 52 rotates, an oil flow from the pump impeller 52 to the turbine runner 53 is generated. This flow of oil is received by the turbine runner 53, and the turbine runner 53 rotates. At this time, the amplification action of the torque converter 3 occurs, and the turbine runner 53 generates a power larger than the power (torque) of the E / G output shaft.

In the lockup-on state, when the E / G output shaft is rotated, the E / G output shaft, the pump impeller 52, and the turbine runner 53 rotate together.

An oil pump 8 is provided between the torque converter 3 and the continuously variable transmission 4. The oil pump 8 is a mechanical oil pump, and the pump shaft is provided so as to rotate integrally with the pump impeller 52 of the torque converter 3. As a result, when the pump impeller 52 is rotated by the power of the engine 2, the pump shaft of the oil pump 8 is rotated, and hydraulic pressure is generated from the oil pump 8.

The continuously variable transmission 4 is a belt-type continuously variable transmission, and transmits the power input from the torque converter 3 to the differential gear 5. The continuously variable transmission 4 includes an input shaft (input shaft) 14, an output shaft (output shaft) 15, a belt transmission mechanism 16, and a forward / backward switching mechanism 17.

The input shaft 14 is connected to the turbine runner 53 of the torque converter 3 and is provided so as to be integrally rotatable around the same rotation axis as the turbine runner 53.

The output shaft 15 is arranged in parallel with the input shaft 14. An output gear 18 is supported on the output shaft 15 so as to be relatively non-rotatable.

The belt transmission mechanism 16 includes a primary shaft 21 and a secondary shaft 22. The primary axis 21 and the secondary axis 22 are arranged on the same axis as the input axis 14 and the output axis 15, respectively.

The belt transmission mechanism 16 has a configuration in which an endless belt 25 is wound around a primary pulley 23 supported by a primary shaft 21 and a secondary pulley 24 supported by a secondary shaft 22.

The primary pulley 23 is a movable sheave that is arranged so as to face the fixed sheave 31 fixed to the primary shaft 21 with the belt 25 interposed therebetween, and is supported by the primary shaft 21 so as to be movable in the axial direction and non-relatively rotatable. It is equipped with 32. A piston 33 fixed to the primary shaft 21 is provided on the side opposite to the fixed sheave 31 with respect to the movable sheave 32, and a piston chamber (oil chamber) 34 is formed between the movable sheave 32 and the piston 33. There is.

The secondary pulley 24 is arranged to face the fixed sheave 35 fixed to the secondary shaft 22 with the belt 25 interposed therebetween, and is supported by the secondary shaft 22 so as to be movable in the axial direction and not to rotate relative to each other. It is equipped with a movable sheave 36. A piston 37 fixed to the secondary shaft 22 is provided on the opposite side of the movable sheave 36 from the fixed sheave 35, and a piston chamber 38 is formed between the movable sheave 36 and the piston 37.

Although not shown, a bias spring for applying an initial pinching pressure (initial thrust) to the belt 25 is interposed between the movable sheave 36 and the piston 37. The elastic force of the bias spring urges the movable sheave 36 and the piston 37 in a direction in which they are separated from each other.

The forward / backward switching mechanism 17 is interposed between the input shaft 14 and the primary shaft 21 of the belt transmission mechanism 16. The forward / backward switching mechanism 17 includes a planetary gear mechanism 41, a clutch C1 and a brake B1.

The planetary gear mechanism 41 includes a carrier 42, a sun gear 43, and a ring gear 44.

The carrier 42 is externally fitted to the input shaft 14 so as to be relatively rotatable. The carrier 42 rotatably supports a plurality of pinion gears 45. The plurality of pinion gears 45 are arranged on the circumference.

The sun gear 43 is supported by the input shaft 14 so as not to rotate relative to each other, and is arranged in a space surrounded by a plurality of pinion gears 45. The gear teeth of the sun gear 43 mesh with the gear teeth of each pinion gear 45.

The ring gear 44 is provided so that its rotation axis coincides with the axis of the primary shaft 21. The primary shaft 21 of the belt transmission mechanism 16 is connected to the ring gear 44. The gear teeth of the ring gear 44 are formed so as to collectively surround the plurality of pinion gears 45, and mesh with the gear teeth of each pinion gear 45.

The clutch C1 is hydraulically switched between an engaged state (on) in which the carrier 42 and the sun gear 43 are directly connected (coupled so as to be integrally rotatable) and an released state (off) in which the direct connection is released.

The brake B1 is provided between the carrier 42 and the transmission case accommodating the torque converter 3 and the continuously variable transmission 4, and allows the carrier 42 to be in an engaged state (on) by hydraulic pressure and to rotate the carrier 42. It can be switched to the released state (off).

A shift lever (select lever) is arranged in the vehicle interior of the vehicle 1 at a position where the driver can operate the vehicle. In the movable range of the shift lever, for example, a P (parking) position, an R (reverse) position, an N (neutral) position, and a D (drive) position are provided in this order in a row.

When the shift lever is in the P position, both the clutch C1 and the brake B1 are released, and the parking lock gear (not shown) is fixed, which is one of the shift ranges of the continuously variable transmission 4. The P range is configured. Further, when the shift lever is in the N position, both the clutch C1 and the brake B1 are released and the parking lock gear is not fixed, so that the N range, which is one of the shift ranges of the continuously variable transmission 4, is set. It is composed. When both the clutch C1 and the brake B1 are released, the input shaft 14 and the sun gear 43 idle, and the power of the engine 2 is not transmitted to the drive wheels 7L and 7R.

When the shift lever is in the D position, the brake B1 is engaged and the clutch C1 is released to form a forward range, which is one of the shift ranges of the continuously variable transmission 4. In the forward range, when the power of the engine 2 is input to the input shaft 14, the sun gear 43 rotates integrally with the input shaft 14 while the carrier 42 is stationary. Therefore, the rotation of the sun gear 43 is transmitted to the ring gear 44 in reverse and decelerated. As a result, the ring gear 44 rotates, and the primary shaft 21 and the primary pulley 23 of the belt transmission mechanism 16 rotate integrally with the ring gear 44. The rotation of the primary pulley 23 is transmitted to the secondary pulley 24 via the belt 25 to rotate the secondary pulley 24 and the secondary shaft 22. Then, the output shaft 15 and the output gear 18 rotate integrally with the secondary shaft 22. The output gear 18 meshes with the differential gear 5 (the input gear of the differential gear 5). When the output gear 18 rotates, the drive shafts 6L and 6R extending to the left and right from the differential gear 5 rotate, and the drive wheels 7L and 7R rotate to advance the vehicle 1.

When the shift lever is in the D position, shift control is performed to automatically shift the gear ratio.

When the shift lever is in the R position, the brake B1 is released and the clutch C1 is engaged to form the R range, which is one of the shift ranges of the continuously variable transmission 4. In the R range, when the power of the engine 2 is input to the input shaft 14, the carrier 42 and the sun gear 43 rotate integrally with the input shaft 14. Therefore, the rotation of the sun gear 43 is transmitted to the ring gear 44 without reversing the rotation direction. As a result, the ring gear 44 rotates, and the primary shaft 21 and the primary pulley 23 of the belt transmission mechanism 16 rotate integrally with the ring gear 44. The rotation of the primary pulley 23 is transmitted to the secondary pulley 24 via the belt 25 to rotate the secondary pulley 24 and the secondary shaft 22. Then, the output shaft 15 and the output gear 18 rotate integrally with the secondary shaft 22. When the output gear 18 rotates, the drive shafts 6L and 6R extending to the left and right from the differential gear 5 rotate, and the drive wheels 7L and 7R rotate, so that the vehicle 1 moves backward.

<Vehicle control system>
FIG. 2 is a block diagram showing the configuration of the control system of the vehicle 1.

Further, the vehicle 1 is equipped with an ECU (Electronic Control Unit) having a configuration including a microcomputer. The microcomputer has, for example, a CPU, ROM and RAM, a data flash (flash memory), and the like. In order to control each part of the vehicle 1, a plurality of ECUs are mounted on the vehicle 1, and each ECU is connected so as to be capable of bidirectional communication by a CAN (Controller Area Network) communication protocol. The plurality of ECUs include an engine ECU 61, a CVT ECU 62, a brake ECU 63, and an IDSE ECU 64. Various sensors necessary for control are connected to the engine ECU 61, the CVT ECU 62, the brake ECU 63, and the IDSE ECU 64.

The engine ECU 61 has an electronic throttle valve, an injector, and an ignition for starting, stopping, and adjusting the output of the engine 2 based on the information acquired from the detection signals of various sensors and / or various information input from other ECUs. Controls plugs, starters, etc.

The CVT ECU 62 is a hydraulic circuit for supplying hydraulic pressure to each part of the torque converter 3 and the continuously variable transmission 4 based on information acquired from detection signals of various sensors and / or various information input from other ECUs. Controls the valves contained in.

The sensor connected to the brake ECU 63 includes a brake sensor 65, a vehicle speed sensor 66, and the like.

The brake sensor 65 outputs a detection signal according to the amount of operation of the brake pedal arranged in the vehicle interior.

The vehicle speed sensor 66 includes, for example, a rotor made of a magnetic material that rotates as the vehicle 1 travels, and an electromagnetic pickup provided in non-contact with the rotor. Every time the rotor rotates by a certain angle, a pulse signal is output as a detection signal from the electromagnetic pickup. Since the frequency of the pulse signal corresponds to the vehicle speed, the brake ECU 63 converts the frequency of the pulse signal input from the vehicle speed sensor 66 into the vehicle speed.

The brake ECU 63 controls the brake actuator 67 and the like based on information acquired from detection signals of various sensors (operation amount of the brake pedal, vehicle speed of the vehicle 1) and / or various information input from other ECUs. , The braking force applied to the wheels by each brake is controlled so that the vehicle 1 is braked while the posture of the vehicle 1 is kept stable.

In the vehicle 1, IDS control (idling stop control) can be executed. IDS control is a technique for improving fuel efficiency by suppressing idling of the engine 2. As information necessary for IDS control, information such as the vehicle speed and the operation amount of the brake pedal is input from the brake ECU 63 to the IDSECU 64.

In the IDS control, when the driver performs a brake operation (for example, a brake pedal depression operation) while the vehicle 1 is running, the IDSECU 64 repeatedly determines whether or not the IDS condition (IDS condition) is satisfied. To. The IDS condition includes a brake condition that the brake operation is continued for a certain period of time or more, and a vehicle speed condition that the vehicle speed is equal to or less than the IDS implementation vehicle speed (for example, 10 km / h) higher than 0 km / h. When all the conditions included in the IDS condition are satisfied, the IDS condition is satisfied. When the IDS condition is satisfied, the IDS ECU 64 outputs an IDS request to the engine ECU 61, and the engine ECU 61 stops the engine 2. Further, according to the satisfaction of the IDS condition, the valve of the hydraulic circuit is controlled by the CVTEC 62, and the clutch C1 is released. As a result, the torque applied to the belt 25 of the continuously variable transmission 4 during the deceleration traveling of the vehicle 1 is reduced, so that the occurrence of belt slip due to sudden braking during the deceleration traveling can be suppressed.

In addition to the braking condition and the vehicle speed condition, the IDS condition includes a steering torque condition that the steering torque applied to the steering mechanism (steering wheel) of the vehicle 1 is less than the IDS prohibited torque, and the SOC of the battery mounted on the vehicle 1. A battery condition that (State Of Charge) is equal to or higher than a predetermined value may be included.

While the engine 2 is stopped by the IDS control, it is repeatedly determined whether or not the predetermined IDS return condition is satisfied. The IDS return condition includes, for example, a condition that the brake operation by the driver is released. When the IDS return condition is satisfied, a restart request is output from the IDS ECU 64 to the engine ECU 61. In response to this restart request, the engine 2 is restarted by the engine ECU 61.

<L / U zero differential pressure control>
FIG. 3 is a diagram showing an example of time-varying changes in the IDS return condition, the establishment / non-establishment of the IDS return condition, the on / off of the zero differential pressure control, the engine rotation speed, and the turbine rotation speed.

Hydraulic pressure is supplied to the release side oil chamber 55 and the engagement side oil chamber 56 of the torque converter 3 from, for example, a lockup control valve (not shown) included in the hydraulic circuit. The lockup control valve is formed with an input port into which the lockup signal pressure is input. For example, when the lockup signal pressure is a predetermined value, the lockup control valve is released from the release side oil chamber 55 and the engagement side. Hydraulic pressure is evenly supplied to the oil chamber 56. When the lockup signal pressure is less than a predetermined value, a higher hydraulic pressure than the engaging side oil chamber 56 is supplied from the lockup control valve to the release side oil chamber 55, and the lockup is turned off. When the lockup signal pressure is larger than a predetermined value, the lockup control valve supplies a hydraulic pressure higher than that of the release side oil chamber 55 to the engaging side oil chamber 56, and the lockup is turned on.

When the IDS return condition is satisfied (time T1), the solenoid valve that generates the lockup signal pressure is controlled by the CVTEC 62, and the lockup signal pressure is set to a predetermined value. As a result, the hydraulic pressure is evenly supplied from the lockup control valve to the release side oil chamber 55 and the engagement side oil chamber 56, and the differential pressure between the oil pressure of the release side oil chamber 55 and the oil pressure of the engagement side oil chamber 56 is increased. It is made zero.

After that, the cranking of the engine 2 is started (time T2). Then, when the engine 2 is started by sparking the spark plug while the engine 2 is cranked, the engine speed starts to increase (time T3).

At this time, since the differential pressure between the hydraulic pressure of the release side oil chamber 55 and the hydraulic pressure of the engaging side oil chamber 56 is zero, when the engine rotation speed increases, the pump impeller 52 of the torque converter 3 rotates with the engine rotation. Centrifugal hydraulic pressure is generated in the oil in the engaging side oil chamber 56, and the centrifugal hydraulic pressure pushes the lockup clutch 54 against the front cover 51. This becomes the resistance to the rotation of the pump impeller 52, and the resistance acts in the drag direction with respect to the engine rotation. As a result, the engine speed changes as shown by the solid line in FIG. 3, and the engine speed is suppressed from rising as shown by the alternate long and short dash line in FIG.

When the generated hydraulic pressure of the oil pump 8 rises sufficiently, the valve of the hydraulic circuit is controlled by the CVTEC 62, and the clutch C1 is engaged. Further, the oil chamber 55 on the release side and the oil chamber 56 on the engagement side are locked up from the lockup control valve so that the lockup is turned off by the CVTEC 62 when the generated hydraulic pressure of the oil pump 8 rises sufficiently or at an appropriate timing before and after the rise. The oil pressure supplied to is controlled.

<Modification example>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other embodiments.

For example, the vehicle 1 equipped with the continuously variable transmission 4 is taken up, but the control device according to the present invention is equipped with a stepped automatic transmission (AT: Automatic Transmission) or a power split type continuously variable transmission. It can also be used for the vehicle 1. The power split type stepless transmission is provided with a stepless transmission mechanism that shifts power steplessly by changing the gear ratio, and splits power (torque) into two paths between an input shaft and an output shaft. It is a transmission that can be transmitted.

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

1: Vehicle 2: Engine 3: Torque converter 4: Continuously variable transmission (automatic transmission)
61: Engine ECU (IDS control means)
62: CVTEC (differential pressure adjusting means)
64: IDSECU (IDS control means)
C1: Clutch (engagement element)

Claims (1)

A torque converter equipped with a lockup clutch that is engaged / disengaged by the differential pressure between the hydraulic pressure in the engaging side oil chamber and the hydraulic pressure in the releasing side oil chamber is provided between the engine and the automatic transmission, and the engine and the vehicle are provided. A control device used in a vehicle equipped with an engaging element that is hydraulically engaged / disengaged to transmit / disconnect power from the wheel.
IDS control means for executing IDS control for stopping the engine when a predetermined IDS start condition is satisfied and restarting the engine when a predetermined IDS return condition is satisfied during the stop. When,
When the IDS return condition is satisfied with the engaging element released, the differential pressure between the hydraulic pressure of the engaging side oil chamber and the hydraulic pressure of the releasing side oil chamber is set to a predetermined value or less, and the engine A vehicle control device including a differential pressure adjusting means for setting the hydraulic pressure of the release side oil chamber to be higher than the hydraulic pressure of the engaging side oil chamber so that the lockup clutch is released after the restart.

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