JP6752520B2 - Vehicle control device - Google Patents

Description

The present invention relates to a control device used in 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 braking operation, the engine is automatically stopped (idling stop). After that, when the driver releases the brake operation, the engine is automatically restarted.

Some vehicles equipped with a belt-type continuously variable transmission (CVT) also adopt IDS control. In that vehicle type, for example, a forward clutch is interposed between the torque converter and the primary pulley of the continuously variable transmission, and when the engine is stopped (deceleration IDS) during deceleration running of the vehicle, the forward clutch is inserted. The clutch is released. As a result, it is possible to suppress the occurrence of slippage (belt slippage) between the pulley and the belt.

Japanese Unexamined Patent Publication No. 2013-181408

After the engine is stopped by IDS control, the pinching pressure decreases as the engine speed decreases, and the allowable torque of the sheave (pulley) decreases. When the allowable torque of the sheave falls below the input torque before the hydraulic pressure (clutch pressure) that engages the forward clutch drops slowly and the allowable torque of the forward clutch drops below the input torque input to the continuously variable transmission. , Belt slippage occurs. Therefore, when the forward clutch is released at the start of IDS control, it is desirable that the clutch pressure of the forward clutch drops quickly.

An object of the present invention is to provide a vehicle control device capable of rapidly reducing the hydraulic pressure of the friction engaging element at the start of IDS control.

In order to achieve the above object, the vehicle control device according to the present invention is involved in transmitting / blocking the power between the engine, the transmission that shifts the power transmitted from the engine to the wheels, and the engine and the wheels. A control device used in a vehicle equipped with a hydraulic friction engaging element to be combined / released and a pressure regulating valve having a drain port for draining the hydraulic pressure of the friction engaging element, and an IDS start condition is satisfied. In the case of the IDS control means that executes the IDS control that stops the engine according to the above and restarts the engine when the IDS return condition is satisfied, and the normal release of the friction engagement element, the drain port has a predetermined opening. Adjust the position of the spool of the pressure regulating valve so that it opens, and when releasing the friction engagement element at the start of IDS control, adjust the position of the spool so that the drain port opens with an opening larger than the predetermined opening. Includes release control means.

According to this configuration, in the IDS control, the engine is stopped in response to the establishment of the IDS start condition (IDS start request), and the engine is restarted in response to the establishment of the IDS return condition (IDS return request) while the engine is stopped. It will be started.

At the start of IDS control, the hydraulic friction engagement element interposed between the engine and the wheels may be released. For example, if the IDS control is started during deceleration of the vehicle, the friction engagement element is released. As a result, the occurrence of belt slip can be suppressed, but if the friction engaging element is released slowly, the occurrence of belt slip may not be suppressed in some cases.

When the friction engaging element in the engaged state is released, the spool of the pressure regulating valve is moved to the position where the drain port is opened. In the case of normal release, the spool is moved to a position where the drain port opens with a predetermined opening. On the other hand, in the case of release at the start of IDS control, the spool is moved to the release side of the drain port beyond the normal release position, and the drain port is opened with an opening larger than a predetermined opening. .. As a result, the hydraulic pressure of the friction engaging element can be quickly released through the drain port, and the hydraulic pressure of the friction engaging element can be quickly reduced.

Since the hydraulic pressure of the friction engaging element can be quickly lowered, the friction engaging element can be quickly released at the start of IDS control during deceleration running of the vehicle, and the safety factor against belt slip is increased.

Further, since the safety factor against belt slippage is increased, a large torque is allowed to be input at the start of the IDS control, so that the IDS control can be executed at a vehicle speed higher than the conventional one. As a result, the effect of improving fuel efficiency by IDS control can be enhanced.

According to the present invention, the hydraulic pressure of the friction engaging element at the start of IDS control can be quickly lowered, and the safety factor against belt slippage can be improved or the fuel consumption can be improved by increasing the vehicle speed at which IDS control is started. be able to.

It is a figure which shows the structure of the main part of the vehicle which mounted the control device which concerns on one Embodiment of this invention. It is a schematic cross-sectional view of a clutch pressure regulating valve, and shows both the state where the spool is located at the engaging position and the state where it is located at the drain position. It is a schematic cross-sectional view of a clutch pressure regulating valve, and shows both the state where the spool is located at the drain position and the state where the spool is located at a position beyond the drain position. It is a figure which shows the relationship between a control pressure and a clutch pressure. It is a figure which shows an example of the time change of an engine speed, a turbine speed, a torque converter torque, a clutch permissible torque, and a sheave permissible torque. It is a figure which shows other example of time change of engine speed, turbine speed, torque converter torque, clutch permissible torque and sheave permissible torque.

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

<Main part composition of the vehicle>
FIG. 1 is a diagram showing a configuration of a main part of a vehicle 1 equipped with a control device according to an embodiment of the present invention.

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) for injecting fuel into the intake air, an ignition plug for generating an electric discharge in the combustion chamber, and the like. Has been done. Further, the engine 2 is provided with a starter for starting the engine 2.

Further, the vehicle 1 is equipped with a torque converter 3 and a belt-type continuously variable transmission (CVT) 4 in order to transmit the output of the engine 2 to the drive wheels.

The continuously variable transmission 4 includes an input shaft 11 to which power from the engine 2 is input, a primary shaft 12 to which power is transmitted from the input shaft 11, a secondary shaft 13 provided in parallel with the primary shaft 12, and a primary. A primary pulley 14 supported by a shaft 12 so as to be relatively non-rotatable, a secondary pulley 15 supported by a secondary shaft 13 so as to be relatively non-rotatable, and a belt 16 wound around the primary pulley 14 and the secondary pulley 15 are provided. There is.

The primary pulley 14 is a movable sheave that is arranged so as to face the fixed sheave 21 fixed to the primary shaft 12 with the belt 16 sandwiched between the fixed sheave 21 and supported by the primary shaft 12 so as to be movable in the axial direction and not to rotate relative to each other. It has 22 and. A piston 23 fixed to the primary shaft 12 is provided on the opposite side of the movable sheave 22 from the fixed sheave 21, and a piston chamber (hydraulic chamber) 24 is formed between the movable sheave 22 and the piston 23. There is.

The secondary pulley 15 is arranged to face the fixed sheave 25 fixed to the secondary shaft 13 with the belt 16 sandwiched between the fixed sheave 25, and is supported by the secondary shaft 13 so as to be movable in the axial direction and unable to rotate relative to each other. It is equipped with a movable sheave 26. A piston 27 fixed to the secondary shaft 13 is provided on the opposite side of the movable sheave 26 from the fixed sheave 25, and a piston chamber (hydraulic chamber) 28 is formed between the movable sheave 26 and the piston 27. There is.

Although not shown, a bias spring is interposed between the movable sheave 26 and the piston 27 to apply an initial pinching pressure (initial thrust) to the belt 16. The elastic force of the bias spring urges the movable sheave 26 and the piston 27 in a direction away from each other.

A hydraulic forward clutch C is interposed between the torque converter 3 and the input shaft 11. The forward clutch C is engaged / disengaged to transmit / shut off the power from the engine 2.

Further, along with the continuously variable transmission 4, a hydraulic circuit 31 for supplying hydraulic pressure to the torque converter 3, the primary pulley 14, the secondary pulley 15, the forward clutch C, and the like is provided. Further, as a source of hydraulic pressure, a mechanical oil pump (MOP) 32 driven by the power of the engine 2 and an electric oil pump (EOP) 33 driven by the power of the electric motor are provided. The hydraulic pressure circuit 31 is supplied with hydraulic pressure generated by the mechanical oil pump 32 and the electric oil pump 33 independently of each other.

The vehicle 1 is provided with an ECU (Electronic Control Unit) having a configuration including a microcomputer (microcontroller unit). 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, the vehicle 1 is equipped with a plurality of ECUs, and each ECU is connected so as to enable bidirectional communication by a CAN (Controller Area Network) communication protocol. The plurality of ECUs include an E / T ECU 41 for controlling the engine 2, a torque converter 3 and a continuously variable transmission 4, and an IDSE ECU 42 for IDS (idling stop) control.

Various sensors required for control are connected to the E / T ECU 41 and the IDSE ECU 42, respectively.

<IDS control>
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 a vehicle speed and an operation amount of a brake pedal is input to the IDSECU 42.

In the IDS control, when the brake pedal is operated (depressed) while the vehicle 1 is running, the IDSECU 42 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 equal to or less than a predetermined idling stop implementation vehicle speed (for example, 10 km / h) and the brake pedal is operated for a certain period of time or longer. While the brake pedal is being operated, it is determined at regular intervals whether or not the IDS start condition is satisfied. Then, when the IDS start condition is satisfied, the IDS ECU 42 transmits an IDS request to the E / T ECU 41, and the E / T ECU 41 stops the engine 2 (idling stop) in response to the IDS request.

After the start of idling stop, the IDSECU 42 determines at regular intervals whether or not the predetermined IDS return condition is satisfied. The IDS return condition is, for example, a condition that the operation of the brake pedal is released during idling stop (the driver's foot is released from the brake pedal). When the IDS return condition is satisfied, the IDS ECU 42 transmits an IDS return request to the E / T ECU 41, and in response to the IDS return request, the E / T ECU 41 operates the starter and restarts the engine 2.

When the IDS start condition is satisfied and the IDS control is started while the vehicle 1 is decelerating, the forward clutch C is released. When the forward clutch C is released, the transmission of power from the engine 2 to the continuously variable transmission 4 is cut off, so that belt slippage occurs between the pulleys (primary pulley 14, secondary pulley 15) and the belt 16. It can be suppressed.

<Clutch pressure control valve>
2A and 2B are schematic cross-sectional views of the clutch pressure regulating valve 51 included in the hydraulic circuit 31.

The clutch pressure regulating valve 51 is a pressure control valve for controlling the hydraulic pressure of the forward clutch C. The clutch pressure adjusting valve 51 includes a spool 52. The spool 52 is housed in a sleeve 53 having a substantially cylindrical peripheral wall, and is provided so as to be movable in the direction of the center line of the sleeve 53.

On the spool 52, substantially columnar land portions 54 and 55 are formed at intervals in the center line direction. The land portions 54 and 55 have the same diameter.

Further, in the sleeve 53, a spring 56 for urging the spool 52 to the other end side (upper side) is provided at one end side (lower side) in the center line direction.

An input port 61, a signal port 62, an output port 63, an operation adjusting port 64, and a drain port 65 are formed on the peripheral wall of the sleeve 53.

The input port 61 communicates with the land portions 54 and 55 depending on the position of the spool 52, and is closed by the land portion 55. The clutch source pressure is input to the input port 61.

The clutch source pressure is the hydraulic pressure output from the clutch modulator valve (not shown). When the line pressure of the hydraulic circuit 31 is equal to or less than a certain pressure, the clutch modulator valve outputs a clutch original pressure having the same pressure as the line pressure, and when the line pressure is higher than the constant pressure, the pressure is reduced to the constant pressure. The original pressure of the clutch is output.

The signal port 62 communicates between the land portion 54 and the upper end of the sleeve 53 regardless of the position of the spool 52. The control pressure output from the linear solenoid valve 71 is input to the signal port 62.

The clutch source pressure is input to the linear solenoid valve 71. By controlling the energization of the linear solenoid valve 71 to the solenoid coil, the clutch original pressure is adjusted by the linear solenoid valve 71, and the control pressure obtained by the pressure adjustment is output from the linear solenoid valve 71.

The output port 63 communicates with the land portions 54 and 55 regardless of the position of the spool 52. Further, the output port 63 communicates with the piston chamber (hydraulic chamber) of the forward clutch C.

The operation adjusting port 64 communicates between the land portion 55 and the lower end of the sleeve 53 regardless of the position of the spool 52. The hydraulic pressure (clutch pressure) output from the output port 63 is fed back to the operation adjustment port 64.

The drain port 65 is closed by the land portion 55 depending on the position of the spool 52, and communicates with the land portions 54 and 55.

<Clutch pressure control>
FIG. 3 is a diagram showing the relationship between the control pressure input to the signal port 62 and the clutch pressure output from the output port 63.

When the E / T ECU 41 controls the energization of the linear solenoid valve 71 and the control pressure is kept constant within the pressure adjustment range below the maximum, the spool 52 is shown in FIG. 2A by the right half of the spool 52. The lower end of the land portion 54 is located at substantially the same position as the lower end of the drain port 65, and the upper end of the land portion 55 is located at substantially the same position as the input port 61. When the control pressure is increased from this state, the spool 52 is pushed down to the spring 56 side to a position corresponding to the control pressure, the input port 61 is opened, and the clutch original pressure is transferred from the input port 61 through the output port 63 to the forward clutch C. Is supplied to. As a result, the hydraulic pressure of the forward clutch C increases. Then, the clutch original pressure output from the output port 63 is also supplied to the operation adjustment port 64, so that the spool 52 returns to the original position. When the control pressure is lowered, the spool 52 is displaced to the signal port 2 side to a position corresponding to the control pressure by the hydraulic pressure supplied to the operation adjustment port 64 and the urging force of the spring 56, and the drain port 65 opens. , The hydraulic pressure of the forward clutch C is drained to the drain port 65 through the output port 63. As a result, the hydraulic pressure of the forward clutch C is lowered. Then, as the hydraulic pressure drops, the hydraulic pressure supplied to the operation adjusting port 64 drops, so that the spool 52 returns to its original position. In this way, by controlling the energization of the linear solenoid valve 71, the clutch pressure supplied to the forward clutch C can be adjusted, and the engagement / disengagement of the forward clutch C can be controlled.

When the forward clutch C is released by IDS control during deceleration running of the vehicle 1, the control pressure is further lowered from the control pressure (lower limit of the pressure adjustment range) when the spool 52 is positioned at the drain position. , The solenoid indicated current value is set by the E / T ECU 41, and the current corresponding to the solenoid indicated current value is energized in the solenoid coil of the linear solenoid valve 71. As a result, as shown in FIG. 2B as the left half of the spool 52, the spool 52 is displaced toward the signal port 62 as compared with the case where the control pressure is adjusted within the pressure adjustment range, and the drain port 65 The opening area is expanded. Therefore, as compared with the case where the control pressure is adjusted within the pressure adjustment range, the hydraulic pressure of the forward clutch C is released earlier from the state in which the forward clutch C is engaged (the clutch pressure drops rapidly).

<Effect>
As described above, when the forward clutch C is released by IDS control during deceleration running of the vehicle 1, the opening area of the drain port 65 becomes larger than that at the time of normal release due to the control pressure exceeding the pressure adjusting range. The linear solenoid valve 71 is controlled so as to expand. As a result, the hydraulic pressure of the forward clutch C can be suddenly lowered, and the forward clutch C can be suddenly released.

FIG. 4 is a diagram showing an example of changes over time in engine speed, turbine speed, torque converter torque, clutch allowable torque, and sheave allowable torque.

When the IDS control is started and the engine 2 is stopped during the deceleration running of the vehicle 1, the difference rotation between the engine speed and the turbine speed of the torque converter 3 increases as the engine speed decreases. The torque converter torque transmitted from the torque converter 3 to the continuously variable transmission 4 becomes large.

As shown in FIG. 4, when the hydraulic pressure of the forward clutch C drops sharply as compared with the conventional case, the difference rotation between the engine rotation speed and the turbine rotation speed of the torque converter 3 is small, and the torque converter torque is small. , The allowable clutch torque drops below the torque converter torque, and the forward clutch C begins to slip. Therefore, the safety factor against belt slippage is higher than in the past, and the occurrence of belt slippage can be satisfactorily suppressed.

FIG. 5 is a diagram showing other examples of changes in engine speed, turbine speed, torque converter torque, clutch allowable torque, and sheave allowable torque over time.

From another point of view, as shown in FIG. 5, if the safety factor against belt slippage is kept the same as in the past, the idling stop implementation vehicle speed can be increased, and the IDS at a higher vehicle speed can be increased. The control can be started. Therefore, the chances of executing the IDS control increase, and the stop time of the engine 2 due to the IDS control can be secured for a long time. As a result, the fuel efficiency of the vehicle 1 can be improved.

<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, in the above-described embodiment, the continuously variable transmission 4 is taken up, but the control device according to the present invention can also be used for a stepped automatic transmission (AT). Further, the control device according to the present invention can also be used for the power split type continuously variable transmission. The power split type continuously variable transmission is provided with a belt-type continuously variable transmission mechanism that shifts power steplessly by changing the gear ratio and a constant transmission mechanism that shifts power at a constant gear ratio, and power of a drive source. Is a transmission that can be transmitted by dividing it into two systems.

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 4: Continuously variable transmission (transmission)
41: E / TEU (control device, IDS control means, release control means)
51: Clutch pressure regulating valve (pressure regulating valve)
52: Spool 65: Drain port C: Forward clutch (friction engagement element)

Claims (1)

An engine, a transmission that shifts the power transmitted from the engine to the wheels, a hydraulic friction engagement element that engages / disengages to transmit / disengage power between the engine and the wheels, and said. A control device used in a vehicle equipped with a pressure regulating valve having a drain port for draining the hydraulic pressure of a friction engaging element.
An IDS control means for executing IDS control in which the engine is stopped when the IDS start condition is satisfied and the engine is restarted when the IDS return condition is satisfied.
In the case of normal release of the friction engaging element, the position of the spool of the pressure adjusting valve is adjusted so that the drain port opens at a predetermined opening degree, and the friction engaging element is released at the start of the IDS control. In this case, a vehicle control device including a release control means for adjusting the position of the spool so that the drain port opens with an opening degree larger than the predetermined opening degree.

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