JP7339834B2 - vehicle - Google Patents

Description

The present invention relates to a vehicle having an idle stop function.

Patent Literature 1 discloses a vehicle having an idle stop function that temporarily stops the engine when a predetermined engine stop condition is satisfied.

Japanese Patent Application Laid-Open No. 2004-352086

When the stopped engine is restarted due to idling stop, the vehicle may experience a shock, and the driver may feel uncomfortable as if the vehicle were to jump out unintentionally. In order to prevent this, the clutch provided in the torque transmission path between the engine and the wheels may be released during idle stop. However, if the clutch is always released during the idle stop, the acceleration response to the accelerator operation decreases because the clutch is re-engaged when the accelerator is turned on and then the vehicle is accelerated.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a vehicle capable of appropriately suppressing the discomfort felt by the driver when the engine is restarted.

In order to solve the above problems, the vehicle of the present invention includes a torque converter connected to the engine, a clutch capable of connecting the torque converter and the wheels, an accelerator sensor for detecting the presence or absence of accelerator operation, and a predetermined idle stop. an engine control unit that performs an idle stop that temporarily stops the engine when a condition is satisfied ; Further, if the turbine rotation speed, which is the rotation speed of the turbine shaft of the torque converter, is equal to or lower than the predetermined rotation speed, the clutch is maintained in the engaged state until a predetermined time elapses after the restart condition is established, and the restart condition is satisfied. a transmission control unit that performs restart clutch control for releasing the clutch when a predetermined time elapses if an accelerator operation is not detected until a predetermined time elapses after establishment.

Further, when the vehicle is decelerating due to idling stop, the transmission control unit, if the restart condition is satisfied and the turbine rotation speed is higher than the predetermined rotation speed, the clutch is operated regardless of whether or not the accelerator is operated. may be maintained in the fastened state.

Further, when the vehicle is decelerating due to idling stop, if the restart condition is satisfied and the turbine rotation speed is equal to or lower than a predetermined rotation speed , the transmission control unit controls the engine after a predetermined delay time elapses. A delayed restart request may be sent to the engine controller requesting that the restart of the engine be initiated.

Further, when the host vehicle is decelerating due to idling stop, the transmission control unit, if the restart condition is satisfied and the turbine rotation speed is higher than a predetermined rotation speed, regardless of the presence or absence of accelerator operation, A normal restart request may be sent to the engine control section requesting that the engine be restarted immediately.

In order to solve the above problems, the vehicle of the present invention includes a torque converter connected to the engine, a clutch capable of connecting the torque converter and the wheels, an accelerator sensor for detecting the presence or absence of accelerator operation, and a brake operation force. an engine control unit that performs an idling stop that temporarily stops the engine when a predetermined idling stop condition is satisfied; is equal to or less than a predetermined strength, the clutch is maintained in the engaged state until a predetermined time elapses after the light braking condition is established, and the accelerator is operated before the predetermined time elapses after the light braking condition is established. and a transmission control unit that performs restart clutch control for releasing the clutch after a predetermined time has elapsed if no detection is made.

Further, when the host vehicle is idle-stopped and stopped, if the strength of the brake operation is greater than a predetermined strength, the transmission control unit does not perform the restart clutch control and maintains the clutch in the engaged state. good.

In addition, when the host vehicle is idle-stopped and stopped, the transmission control unit requests restarting of the engine after a predetermined delay time elapses. A start request may be sent to the engine controller.

Further, when the vehicle is decelerating due to idling stop, the transmission control unit determines that a predetermined restart condition for restarting the engine is satisfied and the turbine rotation speed is the rotation speed of the turbine shaft of the torque converter. is equal to or less than a predetermined number of revolutions , a restart request with a delay is transmitted to the engine control unit, and the delay time of the restart request with a delay when the own vehicle is idle-stopped is It may be shorter than the delay time of the restart request with a delay in the case where the vehicle is decelerating due to a delay.

Advantageous Effects of Invention According to the present invention, it is possible to appropriately prevent the driver from feeling uncomfortable when the engine is restarted.

1 is a schematic diagram showing the configuration of a vehicle according to this embodiment; FIG. 4 is a time chart illustrating an example of the flow of restarting the engine during deceleration; 4 is a time chart illustrating an example of the flow of restarting the engine while the vehicle is stopped; FIG. 10 is a flowchart for explaining the flow regarding the start of idle stop; FIG. 4 is a flowchart for explaining the operation flow of a transmission control unit; 4 is a flowchart for explaining the flow of restart clutch control; 4 is a flowchart for explaining the flow of control regarding restart in an engine control unit;

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present invention are omitted from the drawings. do.

FIG. 1 is a schematic diagram showing the configuration of a vehicle 1 according to this embodiment. In the following, configurations and processes related to this embodiment will be described in detail, and descriptions of configurations and processes unrelated to this embodiment will be omitted. In FIG. 1, the flow of control signals is indicated by dashed arrows.

The vehicle 1 includes an engine 10, a torque converter 12, a clutch 14, a transmission 16, wheels 18, an electric pump 20, a starter 22, a speed sensor 24, an accelerator sensor 26, a brake sensor 28, a turbine speed sensor 30, and an engine control section 32. and transmission control unit 34 . Henceforth, the vehicle 1 may be called an own vehicle.

The engine 10 burns fuel such as gasoline to reciprocate a piston. The reciprocating motion of the piston is converted into rotary motion of the crankshaft through the connecting rod. The crankshaft is connected to torque converter 12 .

Torque converter 12 includes a pump impeller, a turbine liner and a stator. The pump impeller is connected to the crankshaft of engine 10 . A turbine liner is connected to the clutch 14 via the turbine shaft. A stator is located between the pump impeller and the turbine liner. The pump impeller produces oil flow within the torque converter 12 as the crankshaft rotates. The turbine liner receives the flow of oil to drive the turbine shaft. The stator rectifies oil exhausted from the turbine liner and returns it to the pump impeller, thereby producing torque amplification.

The transmission 16 is, for example, a continuously variable transmission. A primary side of the transmission 16 is connected to the clutch 14 . The secondary side of transmission 16 is connected to wheels 18 via a drive shaft. The transmission 16 converts the torque input to the primary side into torque according to the gear ratio between the primary and the secondary, and outputs the torque to the secondary side.

One side of clutch 14 is connected to the turbine shaft of torque converter 12 . The other side of clutch 14 is connected to the primary of transmission 16 . Clutch 14 connects torque converter 12 and transmission 16 by engaging one side and the other side. Further, the clutch 14 mechanically disconnects the torque converter 12 and the transmission 16 by disengaging one side and the other side. That is, the clutch 14 can connect the torque converter 12 and the wheels 18 . The clutch 14 is engaged or released, for example, by the hydraulic pressure of hydraulic oil.

The electric pump 20 operates by consuming power from a battery (not shown). Electric pump 20 supplies hydraulic fluid to clutch 14 and transmission 16 . In addition, in FIG. 1, the dashed-dotted line indicates that hydraulic oil can be supplied.

The starter 22 is, for example, a motor, and consumes power from a battery (not shown) to start and restart the engine 10 . Note that restarting means restarting the temporarily stopped engine 10 .

The speed sensor 24 detects the speed of the vehicle 1 (vehicle speed). The accelerator sensor 26 detects the presence or absence of accelerator operation by the driver and the amount of accelerator operation. Specifically, the accelerator sensor 26 detects whether or not the accelerator pedal is depressed and how much the accelerator pedal is depressed. The brake sensor 28 detects the presence or absence of brake operation by the driver and the strength of the brake operation (brake operation amount). Specifically, the brake sensor 28 detects whether or not the brake pedal is depressed and how much the brake pedal is depressed.

Henceforth, with respect to accelerator operation and brake operation, there is a case where the operation is expressed as ON, and the absence thereof is expressed as OFF.

Turbine speed sensor 30 is provided on the turbine shaft of torque converter 12 . A turbine rotation speed sensor 30 detects the turbine rotation speed, which is the rotation speed of the turbine shaft.

The engine control unit 32 is composed of a semiconductor integrated circuit including a central processing unit (CPU), a ROM storing programs and the like, a RAM as a work area, and the like. The engine control unit 32 mainly controls driving of the engine 10 .

The engine control unit 32 performs an idle stop to temporarily stop the engine 10 when a predetermined idle stop condition is satisfied while the own vehicle is decelerating or stopped. The idle stop condition is, for example, that the speed of the own vehicle is a predetermined speed or less (for example, 10 km/h or less), the brake operation is being performed (brake ON), and the deceleration of the own vehicle is a predetermined deceleration or less. (not sudden deceleration), but the present invention is not limited to this example. In the vehicle 1, fuel efficiency can be improved by performing idle stop.

In the vehicle 1, the engine 10 is restarted when a predetermined restart condition is satisfied during idle stop. The restart condition is, for example, that the brake is switched from on to off during idle stop, but is not limited to this example. It may be determined that the brake is turned off when the hydraulic pressure of the brake becomes equal to or less than a predetermined hydraulic pressure, or it may be determined that the brake is turned off when the amount of depression of the brake pedal becomes zero. .

Further, the restart condition may be established, for example, when the state of charge (SOC) of the battery becomes equal to or lower than a predetermined SOC due to the operation of the vehicle-mounted device. In this case, the engine 10 is restarted regardless of the driver's intention to accelerate the vehicle 1 .

Upon receiving a restart request for restarting the engine 10 during idle stop, the engine control unit 32 operates the starter 22 to restart the engine 10 . There are two types of restart requests in the vehicle 1, a normal restart request and a delayed restart request, which will be described in detail later. When receiving the normal restart request, the engine control unit 32 starts restarting the engine 10 immediately after receiving the normal restart request. On the other hand, when receiving the restart request with delay, the engine control unit 32 restarts the engine 10 after a predetermined time has passed since the restart request with delay was received. Henceforth, this predetermined time may be called a delay time.

The transmission control unit 34 is composed of a semiconductor integrated circuit including a central processing unit (CPU), a ROM storing programs and the like, a RAM as a work area, and the like. Transmission control unit 34 mainly controls torque converter 12 , clutch 14 and transmission 16 .

The transmission control unit 34 transmits a normal restart request or a delayed restart request to the engine control unit 32 when a predetermined restart condition (for example, brake off) is satisfied during idle stop. As a result, the engine control unit 32 restarts the engine 10 in response to the normal restart request or the delayed restart request, as described above.

A battery controller (not shown) that manages the SOC of the battery may transmit a normal restart request to the engine control unit 32 when a predetermined restart condition (for example, the SOC is equal to or lower than a predetermined SOC) is satisfied. In this case, the engine control unit 32 restarts the engine 10 in response to the normal restart request.

Here, the rotation speed (engine rotation speed) of the engine 10 stopped by idle stop is approximately zero. Further, in the torque converter 12, the turbine rotation speed, which is the rotation speed of the turbine shaft, is roughly proportional to the speed of the own vehicle.

For example, assume that the engine 10, which has been stopped due to idle stop, is restarted while the speed of the own vehicle is close to zero, ie, the turbine speed is relatively low. When the engine speed increases from zero while the turbine speed is decreasing according to the speed of the host vehicle, the speed ratio in the torque converter 12 increases. As the speed ratio increases, the torque amplifying action in the torque converter 12 increases. As a result, the torque converter 12 outputs torque increased by the torque amplifying action.

When a high torque is transmitted from the torque converter 12 to the wheels 18, the vehicle 1 undergoes a relatively large acceleration that pushes the vehicle forward. This acceleration causes the vehicle 1 to experience a shock that makes it pop out. In this case, the driver may feel uncomfortable as if the vehicle 1 were to jump out unintentionally.

In order to prevent such discomfort, the clutch 14 may be released during idle stop. However, if the clutch 14 is always released during idling stop, the clutch 14 is re-engaged when the accelerator is turned on, and then the vehicle is accelerated. In addition, when the clutch 14 is released, there is a possibility that a shock due to the re-engagement of the clutch 14 may occur.

Therefore, in the vehicle 1, the clutch 14 is basically engaged during the idle stop, and the clutch 14 is released only in limited situations where the driver is likely to feel uncomfortable, so that the driver feels uncomfortable. The clutch 14 is maintained in the engaged state in situations where the possibility of such an event is low. The engagement and disengagement of the clutch 14 will be specifically described below.

First, the acceleration of the vehicle 1 is estimated to be 0.4 G (G is gravitational acceleration) or more when the driver actually feels a shock that causes the vehicle 1 to fly out. When the acceleration of the vehicle 1 is 0.4 G, for example, it is estimated that the torque transmitted to the clutch 14 is about 13.2 Nm and the turbine speed is about 600 rpm. The speed of the vehicle 1 is approximately 5 km/h when the turbine speed is approximately 600 rpm. In other words, it is estimated that the driver actually feels a shock that makes the vehicle 1 jump out when the turbine rotation speed is 600 rpm or less (vehicle 1 speed is 5 km/h or less).

From this, the turbine rotation speed (for example, 600 rpm) corresponding to the lower limit value (specifically, 0.4 G) of the acceleration of the vehicle 1, which is estimated to cause the driver to feel a shock that makes the vehicle 1 jump out, is A predetermined number of revolutions is set.

Then, when the engine 10 is idle-stopped and the vehicle 1 is decelerating, the transmission control unit 34, when the restart condition is satisfied and the turbine rotation speed is equal to or lower than a predetermined rotation speed, clutches the clutch after the elapse of a predetermined time. 14 is opened. Since the clutch 14 is released, even if a high torque is generated in the turbine shaft when the engine 10 is restarted, the torque of the turbine shaft is not transmitted to the wheels 18 . Therefore, it is possible to avoid the occurrence of a shock that causes the vehicle 1 to jump out.

On the other hand, when the turbine rotation speed exceeds a predetermined rotation speed (for example, 600 rpm), the acceleration of the vehicle 1 is less than 0.4 G, so it is estimated that a large shock that the driver actually feels does not occur.

Therefore, the transmission control unit 34 maintains the clutch 14 in the engaged state if the turbine rotation speed is higher than the predetermined rotation speed when the restart condition is satisfied during the idle stop. In this case, even if the turbine shaft torque is transmitted to the wheels 18 via the clutch 14 as the engine 10 is restarted, the torque is not large enough to shock the driver, and the driver may feel uncomfortable. low sex. Further, since the clutch 14 is maintained in the engaged state, the vehicle 1 can be immediately accelerated according to the driver's accelerator operation. Moreover, since the vehicle 1 does not re-engage the clutch 14, it is possible to avoid a shock caused by the re-engagement of the clutch 14.

Further, as described above, the transmission control unit 34 releases the clutch 14 when the restart condition is satisfied during deceleration and the turbine rotation speed is equal to or lower than the predetermined rotation speed. Instead, the clutch 14 is released after a predetermined time has elapsed.

Here, when the brake is switched from on to off and the restart condition is satisfied, there is a high possibility that the accelerator will be turned on thereafter. If the clutch 14 is released immediately after the restart condition is satisfied, the clutch 14 must be immediately re-engaged when the accelerator is turned on after the clutch 14 is released. In this case, it takes time to re-engage the clutch 14, and there is a possibility that the vehicle 1 may experience a shock when the clutch 14 is re-engaged.

Therefore, when the restart condition is satisfied and the turbine rotation speed is equal to or less than a predetermined rotation speed, the transmission control unit 34 performs a predetermined Clutch 14 is released when time elapses. That is, the transmission control unit 34 maintains the clutch 14 in the engaged state until a predetermined time elapses after the restart condition is satisfied, and maintains the accelerator operation until the predetermined time elapses after the restart condition is satisfied. is detected, the clutch 14 is maintained in the engaged state even after the lapse of a predetermined time.

Thus, in the vehicle 1, within a predetermined time after a predetermined condition (specifically, a restart condition during deceleration) is met, it is determined whether or not the driver has operated the accelerator, that is, whether the driver intends to accelerate. Deciding. Henceforth, this predetermined time may be called acceleration intention confirmation time.

In the vehicle 1, by waiting for the release of the clutch 14 until the acceleration intention confirmation time elapses, when the accelerator is turned on before the acceleration intention confirmation time elapses after the restart condition is satisfied, the clutch 14 is in the engaged state. Since it is maintained, re-engagement of the clutch 14 can be avoided. Therefore, in the vehicle 1, the shock of the vehicle 1 due to the re-engagement of the clutch 14 can be avoided. Also, in the vehicle 1, by setting the acceleration intention confirmation time to an appropriate length, even if the accelerator is turned on before the acceleration intention confirmation time elapses, the deterioration of the acceleration response to the driver's accelerator operation can be suppressed. can be done.

Further, for example, it is assumed that an accelerator operation is detected before the acceleration intention confirmation time elapses. In this case, since the clutch 14 is maintained in the engaged state, if the turbine rotation speed is equal to or lower than the predetermined rotation speed, high torque of the turbine shaft is transmitted to the wheels 18 via the clutch 14, causing a shock that causes the vehicle 1 to fly out. may be felt by the driver.

However, the driver indicates the intention to accelerate by operating the accelerator, and the shock that causes the vehicle 1 to jump out does not go against the driver's intention to accelerate. Therefore, even if the driver feels a shock that causes the vehicle 1 to jump out, the driver is less likely to perceive the shock as a sense of discomfort. As a result, in the vehicle 1, even if the clutch 14 is maintained in the engaged state until the acceleration intention confirmation time elapses, it is possible to prevent the driver from feeling uncomfortable.

In this way, the transmission control unit 34 maintains the clutch 14 in the engaged state until the acceleration intention confirmation time elapses after the predetermined condition (specifically, the restart condition) is established, and the predetermined condition (specifically, If the accelerator operation is not detected until the acceleration intention confirmation time elapses after the restart condition is satisfied, the clutch 14 is released when the acceleration intention confirmation time elapses. Hereinafter, such control of the clutch 14 may be referred to as restart clutch control.

Further, in the vehicle 1, the release of the clutch 14 is waited until the acceleration intention confirmation time elapses due to the restart clutch control. to avoid doing so. Specifically, when the restart clutch control is performed, the start of restarting the engine 10 is delayed so that the engine speed is increased after the acceleration intention confirmation time has elapsed.

That is, when the vehicle 1 is idle-stopped and decelerated, the restart condition is satisfied, and if the turbine rotation speed is equal to or lower than a predetermined rotation speed, the transmission control unit 34 issues a restart request with a delay to the engine control unit. 32. In this case, the engine control unit 32 starts restarting the engine 10 after a predetermined delay time has elapsed after receiving the restart request with delay.

On the other hand, if the restart condition is met and the turbine speed is higher than the predetermined speed, the transmission control unit 34 does not perform the restart clutch control, so it sends a normal restart request to the engine control unit 32 . In this case, the engine control unit 32 immediately restarts the engine 10 in response to receiving the normal restart request.

FIG. 2 is a time chart illustrating an example of the flow of restarting the engine 10 during deceleration. In FIG. 2, it is assumed that the idle stop condition is met during deceleration and the deceleration is continued with the engine 10 stopped. Assume that the brake is switched from ON to OFF at time T10 during deceleration and the restart condition is satisfied. Assume that the turbine rotation speed is equal to or lower than a predetermined rotation speed when the restart condition is satisfied.

The transmission control unit 34 transmits a restart request with delay to the engine control unit 32 because the restart condition is satisfied during deceleration and the turbine speed is equal to or less than the predetermined speed. Then, the engine control unit 32 starts the operation of the starter 22 at time T11 after a predetermined delay time (for example, 0.2 seconds) from the reception of the delayed restart request. The starter 22 thereby rotates the crankshaft of the engine 10 .

The engine 10 switches to rotation of the crankshaft by the reciprocating motion of the piston at time T12 after a predetermined time has elapsed since the starter 22 started rotating the crankshaft. As a result, the engine 10 is restarted, and the engine speed increases from zero due to fuel combustion. Hereinafter, the time during which the crankshaft is rotated by the starter 22 (from time T11 to time T12) may be referred to as starter time. The starter time is, for example, 0.5 seconds, although it depends on the type of starter 22 .

Here, the acceleration intention confirmation time is the sum of the delay time from when the engine control unit 32 receives the restart request with delay until the starter 22 starts operating, and the starter time to continue the operation of the starter 22. set shorter than the time. In other words, the end time T14 of the acceleration intention confirmation time is set between the time T11 when the operation of the starter 22 is started and the time T12 when the operation of the starter 22 is finished. Specifically, the acceleration intention confirmation time is the sum of the release switching time, which is the time required to switch the clutch 14 from the engaged state to the disengaged state, and the acceleration intention confirmation time, which is the sum of the delay time and the starter time. set equal to the time

With reference to FIG. 2, three patterns with different accelerator-on timings will be described. First, the first pattern is when the accelerator is turned on within the acceleration intention confirmation time. During the acceleration intention confirmation time, the hydraulic pressure of the clutch 14 is high and it is in the engaged state. When the accelerator is turned on during the acceleration intention confirmation time, the hydraulic pressure of the clutch 14 is maintained at a high state even after the acceleration intention confirmation time elapses. Therefore, the clutch 14 is maintained in the engaged state.

In the first pattern, the clutch 14 is engaged when the engine speed increases, so a high torque is transmitted to the wheels 18 as the engine speed increases, and the vehicle 1 is shocked. However, in the first pattern, the accelerator is turned on immediately before the shock occurs in the vehicle 1, so the shock of the vehicle 1 does not go against the driver's intention to accelerate, and the driver is less likely to feel discomfort. .

The second pattern is a case where the accelerator is turned on after the acceleration intention confirmation time has elapsed and after the engine 10 has been restarted and maintained at the target rotation speed. Before the acceleration intention confirmation time elapses, the hydraulic pressure of the clutch 14 is high and it is in the engaged state. When the acceleration intention confirmation time elapses, the hydraulic pressure of the clutch 14 is lowered and the clutch 14 is released.

In the second pattern, the clutch 14 is released when the engine speed increases, so the high torque generated as the engine speed increases is not transmitted to the wheels 18 . Therefore, in the second pattern, the vehicle 1 can be prevented from being shocked.

Also, the hydraulic pressure of the clutch 14 is increased little by little after being completely decreased. The hydraulic pressure of the clutch 14 is rapidly increased to a predetermined value when the accelerator is turned on. Thereby, the clutch 14 is engaged. Then, the vehicle 1 is accelerated according to the accelerator operation amount.

In the third pattern, the accelerator is turned on after the acceleration intention confirmation time has passed and the engine speed is increasing from zero to the target speed (time T15 between time T12 and time T13). is. When the acceleration intention confirmation time elapses, the hydraulic pressure of the clutch 14 is lowered and the clutch 14 is switched from the engaged state to the released state.

In the third pattern, when the accelerator is turned on while the engine speed is increasing to the target speed, the hydraulic pressure of the clutch 14 is rapidly increased to a predetermined value, and the clutch 14 is switched from the released state to the engaged state. Since the clutch 14 is engaged while the engine speed is increasing, the vehicle 1 may experience a shock at the timing when the clutch 14 is engaged. However, in the third pattern, a shock is generated in the vehicle 1 when the accelerator is turned on, so the driver is less likely to feel uncomfortable.

Next, a case where an idle stop is started during deceleration and the vehicle stops (stops) without restarting the engine 10 will be described. In this case, although the brake is on, the strength of the brake (the amount of brake operation) may be relatively weak (the amount of brake operation is small). Hereinafter, a braking operation with relatively weak strength may be referred to as weak braking, and a braking operation with relatively strong strength may be referred to as strong braking.

For example, when the vehicle 1 slowly decelerates and stops due to the weak braking, it is highly likely that the weak braking will continue thereafter rather than the accelerator being turned on. In such a case, rather than restarting the engine 10 due to the driver's intention to accelerate, the engine 10 may be restarted for a reason unrelated to the driver's intention to accelerate (for example, a decrease in SOC due to the operation of the vehicle-mounted device). highly sexual.

Since the speed is zero while the vehicle 1 is stopped, when the clutch 14 is engaged and the engine 10 is restarted regardless of the driver's intention to accelerate, high torque output from the torque converter 12 is transmitted to the wheels 18. be done. If a weak brake is applied while the vehicle 1 is stopped, the torque transmitted to the wheels 18 overcomes the braking force of the weak brake, causing a shock that causes the vehicle 1 to jump out. Then, even though the driver is applying the brakes, a shock is generated that causes the vehicle 1 to jump out, which is highly likely to give the driver a sense of discomfort.

Therefore, when the vehicle 1 is idle-stopped and stopped, if a predetermined weak braking condition is satisfied, the transmission control unit 34 performs the same operation as when the turbine rotation speed is equal to or lower than the predetermined rotation speed. A restart request is transmitted to the engine control unit 32, and restart clutch control is performed.

It is assumed that the predetermined weak braking condition is that the strength of the braking operation is equal to or less than a predetermined strength. Here, the predetermined strength is a braking force equal to the driving force corresponding to the lower limit value (specifically, 0.4 G) of the acceleration of the vehicle 1, which is estimated to cause the driver to feel a shock that makes the vehicle 1 jump out. is the strength of the braking operation that causes For example, the transmission control unit 34 may determine that the light braking condition is satisfied when the hydraulic pressure of the brake is equal to or less than the predetermined hydraulic pressure corresponding to the above-described predetermined strength. If the amount of depression is equal to or less than a predetermined amount of depression corresponding to the pressure, it may be determined that the weak braking condition is established.

When the weak brake condition is satisfied and the delayed restart request is transmitted, the engine 10 is restarted after a predetermined delay time. Further, when the weak brake condition is established and the restart clutch control is performed, the clutch 14 is released after the acceleration intention confirmation time elapses. As a result, when the weak braking is continued, the clutch 14 is released and the engine 10 is restarted.

In the vehicle 1, by intentionally restarting the engine 10 when the light braking is continued, it is possible to avoid restarting the engine 10 for reasons unrelated to the driver's intention to accelerate. can. Further, in the vehicle 1, the clutch 14 is released when the engine 10 is intentionally restarted, so shocks to the vehicle 1 when the engine 10 is restarted can be avoided.

Further, the transmission control unit 34 brings the clutch 14 into the engaged state when the vehicle 1 is stopped during idle stop and the strength of the brake is stronger than that of the weak brake (in the case of the strong brake). For example, the transmission control unit 34 maintains the clutch 14 in the engaged state if the clutch 14 has been engaged immediately before, such as when the hard brake is maintained. Further, if the clutch 14 has been released immediately before, such as when the weak brake changes to the strong brake, the transmission control unit 34 switches the clutch 14 from the released state to the engaged state.

When the vehicle 1 is stopped with a strong brake, even if a high torque is transmitted to the wheels 18, the braking force by the brakes overcomes the torque of the wheels 18, and the vehicle 1 does not experience any shock. Therefore, in the case of heavy braking, even if the clutch 14 is engaged, the driver is less likely to feel uncomfortable.

FIG. 3 is a time chart illustrating an example of the flow of restarting the engine while the vehicle 1 is stopped. In FIG. 3, it is assumed that the idle stop condition is satisfied during deceleration, and the speed of the vehicle 1 decreases while the engine 10 is stopped. Then, it is assumed that the engine 10 is not restarted and the speed becomes zero at time T20 with the weak brake applied.

The transmission control unit 34 transmits a delay-equipped restart request to the engine control unit 32 because the weak brake is applied while the vehicle 1 is stopped. Then, the engine control unit 32 starts the operation of the starter 22 at time T21 after a predetermined delay time from the reception of the restart request with delay. The engine speed due to fuel combustion rises from zero at time T22 when a predetermined starter time has elapsed since the starter 22 started operating, and then rises to the target speed at time T23.

Here, when the vehicle 1 is stopped with a weak brake, the acceleration intention confirmation time may be set relatively short because the possibility that the accelerator will be immediately turned on is relatively low. In accordance with this, the delay time in the case of weak braking may be set shorter than the delay time in the case of the above-described turbine rotation speed being equal to or lower than the predetermined rotation speed. Note that the end time T24 of the acceleration intention confirmation time is set between the time T21 and the time T22.

If the delay time and acceleration intention confirmation time are set relatively short, the clutch 14 will be released early. Therefore, the vehicle 1 can quickly avoid a shock to the vehicle 1 caused by a restart that is not related to the driver's intention to accelerate in a situation where the vehicle 1 is stopped with weak braking.

Further, for example, like waiting for a right turn, the accelerator may be turned on early after the vehicle 1 stops with a weak brake. For this reason, the vehicle 1 does not start restarting immediately, but at least provides a delay time. As a result, in the vehicle 1, the clutch 14 can be appropriately maintained in the engaged state when the accelerator is turned on early. As a result, in the vehicle 1, even if the accelerator operation is performed early after stopping with the weak brake, the deterioration of the acceleration response to the driver's accelerator operation can be suppressed.

Also, FIG. 3 illustrates a first pattern, a second pattern, and a third pattern in which the accelerator is turned on at different timings. Since the operations of the first to third patterns in FIG. 3 are the same as those in FIG. 2, description thereof is omitted. Note that time T25 in FIG. 3 shows an example of the time when the accelerator is turned on while the engine speed is increasing from zero to the target speed.

FIG. 4 is a flowchart for explaining the flow relating to the start of idle stop. The engine control unit 32 repeats the series of processes shown in FIG. 4 at each interrupt timing that occurs in a predetermined control cycle.

First, the engine control unit 32 determines whether or not an idle stop condition is satisfied (S100). If the idle stop condition is satisfied (YES in S100), the engine control unit 32 starts the idle stop and ends the series of processes. That is, the engine control section 32 temporarily stops the engine 10 . Note that the engine control unit 32 may turn on an idling stop flag indicating that the idling stop is being performed when the idling stop is started.

If the idle stop condition is not satisfied (NO in S100), the engine control unit 32 ends the series of processes.

FIG. 5 is a flowchart for explaining the operation flow of the transmission control unit 34. As shown in FIG. The transmission control unit 34 repeats the series of processes shown in FIG. 5 at each interrupt timing that occurs in a predetermined control cycle.

First, the transmission control unit 34 determines whether or not the idle stop is being performed (S200). For example, the transmission control unit 34 may determine that the idle stop is being performed when the idle stop flag is ON. If the idle stop is not being performed (NO in S200), the transmission control unit 34 terminates the series of processes.

If it is during idle stop, the transmission control unit 34 determines whether or not the host vehicle is stopped (S210). Specifically, the transmission control unit 34 determines that the host vehicle is stopped when the speed detected by the speed sensor 24 is zero.

If the host vehicle is not stopped (NO in S210), the vehicle is decelerating due to idling stop, so the transmission control unit 34 determines whether or not the restart condition is satisfied (S220).

If the restart condition is satisfied (YES in S220), the transmission control unit 34 acquires the turbine rotation speed from the torque converter 12 and determines whether or not the turbine rotation speed is equal to or less than a predetermined rotation speed (S230).

If the turbine speed is equal to or less than the predetermined speed (YES in S230), the transmission control unit 34 transmits a restart request with delay to the engine control unit 32 (S240). Then, the transmission control unit 34 performs restart clutch control (S250), and ends the series of processes. The flow of restart clutch control will be described later.

If the turbine speed is not equal to or lower than the predetermined speed (NO in S230), the deceleration is higher than the predetermined speed, and the transmission control unit 34 transmits a normal restart request to the engine control unit 32 (S260). ). Then, the transmission control unit 34 maintains the clutch 14 in the engaged state (S270), and ends the series of processes. In this case, even if the engine 10 is restarted, the torque transmitted to the wheels 18 is relatively low, so that the vehicle 1 does not jump out.

If the restart condition is not satisfied (NO in S220), the transmission control unit 34 maintains the clutch 14 in the engaged state (S270), and terminates the series of processes. In this case, idle stop is continued.

If the own vehicle is stopped (YES in S210), the own vehicle has been idle-stopped and stopped, and the transmission control unit 34 determines whether or not the weak brake condition is satisfied (S300). Specifically, the transmission control unit 34 acquires the strength of the braking operation from the brake sensor 28, and determines that the weak braking condition is met when the strength of the braking operation is equal to or less than a predetermined strength.

If the weak braking condition is satisfied (YES in S300), the transmission control unit 34 transmits a restart request with delay to the engine control unit 32 (S240). Then, the transmission control unit 34 performs restart clutch control (S250), and ends the series of processes.

On the other hand, if the light braking condition is not satisfied (NO in S300), that is, if the strength of the braking operation is greater than the predetermined strength, the transmission control unit 34 maintains the clutch 14 in the engaged state (S310), end the processing of In this case, even if the engine 10 is restarted, the braking force of the brake is larger than the driving force of the torque transmitted to the wheels 18, so that the vehicle 1 does not jump out.

FIG. 6 is a flowchart for explaining the flow of restart clutch control. When the restart clutch control is started, the transmission control unit 34 first determines whether or not the acceleration intention confirmation time has elapsed (S400).

If the acceleration intention confirmation time has not elapsed (NO in S400), the transmission control unit 34 maintains the clutch 14 in the engaged state (S410). That is, the clutch 14 is maintained in the engaged state during the acceleration intention confirmation time.

Next, the transmission control unit 34 acquires presence/absence of accelerator operation from the accelerator sensor 26, and determines whether or not the accelerator is turned on (S420).

If the accelerator is not turned on (NO in S420), the transmission control unit 34 returns to step S400 for determining whether or not the acceleration intention confirmation time has elapsed, and repeats the processes after step S400.

If the accelerator is turned on (YES in S420), the transmission control unit 34 terminates the series of processes. In this case, the clutch 14 is maintained in the engaged state even after the acceleration intention confirmation time has elapsed.

If the acceleration intention confirmation time has elapsed (YES in S400), the transmission control unit 34 switches the clutch 14 from the engaged state to the released state (S430), and ends the series of processes.

FIG. 7 is a flowchart for explaining the flow of control for restarting in the engine control unit 32. As shown in FIG. The engine control unit 32 repeats the series of processing in FIG. 7 at each interrupt timing that occurs in a predetermined control cycle.

First, the engine control unit 32 determines whether or not the idle stop is being performed (S500). If the idle stop is not being performed (NO in S500), the engine control unit 32 terminates the series of processes.

If the idle stop is being performed (YES in S500), the engine control unit 32 determines whether or not a restart request with delay has been received (S510). When the restart request with delay is received (YES in S510), the engine control unit 32 performs restart control with delay (S520). Specifically, the engine control unit 32 restarts the engine 10 by starting the operation of the starter 22 after waiting until a predetermined delay time elapses after receiving the restart request with delay.

If the restart request with delay has not been received (NO in S510), the engine control unit 32 determines whether or not the normal restart request has been received (S530). If the normal restart request has not been received (NO in S530), the engine control unit 32 terminates the series of processes. When the normal restart request is received (YES in S530), the engine control unit 32 performs normal restart control (S540). Specifically, the engine control unit 32 restarts the engine 10 by starting the operation of the starter 22 immediately after receiving the normal restart request.

As described above, the transmission control unit 34 of the vehicle 1 according to the present embodiment, when the host vehicle is decelerating due to idle stop, has passed a predetermined time (acceleration intention confirmation time) after the restart condition is established. The clutch 14 is maintained in the engaged state until the restart condition is established, and restart clutch control is performed to release the clutch 14 when the prescribed time elapses if the accelerator operation is not detected until the prescribed time elapses after the restart condition is established.

As a result, in the vehicle 1 of the present embodiment, when the accelerator operation is performed immediately after the restart condition is satisfied, even if a shock that causes the vehicle 1 to jump out occurs, the driver does not intend to accelerate. Therefore, it is possible to prevent the driver from feeling uncomfortable. Further, in this case, since the clutch 14 is maintained in the engaged state, a shock to the vehicle 1 due to the re-engagement of the clutch 14 can be avoided. In addition, in the vehicle 1 of the present embodiment, the clutch 14 is released when the accelerator operation is not performed immediately after the restart condition is satisfied, so that a shock that causes the vehicle 1 to jump out can be reliably avoided.

Therefore, according to the vehicle 1 of the present embodiment, it is possible to appropriately prevent the driver from feeling uncomfortable when the engine 10 is restarted.

Further, in the vehicle 1 of the present embodiment, when the host vehicle is decelerating due to idle stop, the restart clutch control is performed when the restart condition is satisfied and the turbine rotation speed is equal to or lower than a predetermined rotation speed. done. Therefore, in the vehicle 1 of the present embodiment, it is possible to more reliably prevent the driver from feeling uncomfortable in a situation where a shock that causes the vehicle 1 to fly out occurs.

Further, in the vehicle 1 of this embodiment, when the own vehicle is decelerating due to idling stop, if the restart condition is satisfied and the turbine rotation speed is higher than the predetermined rotation speed, regardless of the presence or absence of the accelerator operation. First, the clutch 14 is maintained in the engaged state. Therefore, in the vehicle 1 of the present embodiment, it is possible to avoid unnecessary disengagement and re-engagement of the clutch 14 in a situation where a shock such as the vehicle 1 jumping out is unlikely to occur. A decrease in response can be suppressed.

Further, in the vehicle 1 of the present embodiment, when the own vehicle is decelerating due to idling stop, the restart request with delay is transmitted to the engine control unit 32 when the restart condition is satisfied. Therefore, in the vehicle 1 of the present embodiment, it is possible to prevent the engine 10 from being restarted before the predetermined time (acceleration intention confirmation time) for confirming the detection of the accelerator operation has elapsed.

Further, in the vehicle 1 of the present embodiment, when the own vehicle is decelerating due to idling stop, if the restart condition is satisfied and the turbine rotation speed is equal to or lower than a predetermined rotation speed, the restart request with delay is executed. is sent to the engine control unit 32 . Therefore, in the vehicle 1 of the present embodiment, it is possible to more reliably prevent the engine 10 from being restarted before the acceleration intention confirmation time elapses in a situation where a shock occurs such that the vehicle 1 jumps out.

Further, in the vehicle 1 of this embodiment, when the own vehicle is decelerating due to idling stop, if the restart condition is satisfied and the turbine rotation speed is higher than the predetermined rotation speed, regardless of the presence or absence of the accelerator operation. First, a normal restart request is sent to the engine control unit 32 . For this reason, in the vehicle 1 of the present embodiment, it is possible to avoid unnecessary confirmation of the intention to accelerate in a situation in which a shock that would cause the vehicle 1 to jump out is unlikely to occur, thereby suppressing a decrease in acceleration response. can be done.

Further, the transmission control unit 34 of the vehicle 1 according to the present embodiment, when the own vehicle is idle-stopped and stopped, sets a predetermined amount after a weak braking condition in which the strength of the braking operation is equal to or less than a predetermined strength is established. The clutch 14 is maintained in the engaged state until the time (acceleration intention confirmation time) elapses, and if the accelerator operation is not detected until the predetermined time elapses after the weak brake condition is established, the clutch 14 is engaged after the elapse of the predetermined time. The restart clutch control is performed to release the

As a result, in the vehicle 1 of the present embodiment, when the accelerator operation is performed immediately after the weak brake condition is established, even if a shock that causes the vehicle 1 to jump out occurs, the driver does not intend to accelerate. Therefore, it is possible to prevent the driver from feeling uncomfortable. Further, in this case, since the clutch 14 is maintained in the engaged state, a shock to the vehicle 1 due to the re-engagement of the clutch 14 can be avoided. Further, in the vehicle 1 of the present embodiment, when the accelerator operation is not performed immediately after the weak brake condition is established, the clutch 14 is released. You can definitely avoid the shock.

Therefore, according to the vehicle 1 of the present embodiment, it is possible to appropriately prevent the driver from feeling uncomfortable when the engine 10 is restarted.

Further, in the vehicle 1 of the present embodiment, when the own vehicle is idle-stopped and stopped, if the strength of the brake operation is greater than a predetermined strength, the restart clutch control is not performed, and the clutch 14 is in the engaged state. maintained. Therefore, in the vehicle 1 of the present embodiment, it is possible to avoid unnecessary disengagement and re-engagement of the clutch 14, and it is possible to suppress a decrease in acceleration response in response to subsequent accelerator operation.

Further, in the vehicle 1 of the present embodiment, when the host vehicle is idle-stopped and stopped, a restart request with delay is transmitted to the engine control unit 32 when the weak braking condition is satisfied. Therefore, in the vehicle 1 of this embodiment, it is possible to prevent the engine 10 from being restarted before the acceleration intention confirmation time elapses.

Further, in the vehicle 1 of the present embodiment, the delay time of the restart request with delay when the host vehicle is idle-stopped and stopped is the restart-with-delayed restart request when the host vehicle is idle-stopped and decelerated. Less than the request delay time. Therefore, in the vehicle 1 of the present embodiment, when the own vehicle is stopped and there is a low possibility that the driver's intention to accelerate will be indicated immediately, the shock to the vehicle 1 caused by restarting that is not related to the driver's intention to accelerate can be more reliably avoided. can do.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope of the claims, and it should be understood that these also belong to the technical scope of the present invention. be done.

For example, in the above embodiment, the starter time is about 0.5 seconds. However, in the above embodiment, a starter 22 with a shorter starter time may be used. In this case, the delay time may be set longer due to the shorter starter time.

INDUSTRIAL APPLICABILITY The present invention can be used for vehicles having an idle stop function.

1 vehicle 10 engine 12 torque converter 14 clutch 18 wheel 26 accelerator sensor 28 brake sensor 32 engine controller 34 transmission controller

Claims (8)

a torque converter connected to the engine;
a clutch capable of connecting the torque converter and a wheel;
an accelerator sensor that detects the presence or absence of an accelerator operation;
an engine control unit that performs an idle stop for temporarily stopping the engine when a predetermined idle stop condition is satisfied;
A predetermined restart condition for restarting the engine is satisfied when the host vehicle is idle-stopped and decelerated , and the turbine rotation speed, which is the rotation speed of the turbine shaft of the torque converter, is equal to or less than a predetermined rotation speed. Then, the clutch is maintained in the engaged state until a predetermined time elapses after the restart condition is satisfied, and the accelerator operation is detected before the predetermined time elapses after the restart condition is satisfied. a transmission control unit that performs a restart clutch control that releases the clutch when the predetermined time elapses if not, and
vehicle equipped with If the restart condition is satisfied and the turbine rotation speed is higher than a predetermined rotation speed when the host vehicle is decelerating due to idling stop, the transmission control unit determines whether or not the accelerator is operated. 2. The vehicle according to claim 1, wherein the clutch is maintained in the engaged state regardless of whether the clutch is engaged. When the host vehicle is decelerating due to idling stop, the transmission control unit controls that, when the restart condition is satisfied and the turbine rotation speed is equal to or lower than a predetermined rotation speed , a predetermined delay time elapses. 3. The vehicle according to claim 1, wherein a delay-added restart request requesting restart of the engine is transmitted to the engine control unit after the engine is restarted. If the restart condition is satisfied and the turbine rotation speed is higher than a predetermined rotation speed when the host vehicle is decelerating due to idling stop, the transmission control unit determines whether or not the accelerator is operated. 4. The vehicle according to any one of claims 1 to 3, wherein a normal restart request requesting that the engine be restarted immediately is transmitted to the engine control unit. a torque converter connected to the engine;
a clutch capable of connecting the torque converter and a wheel;
an accelerator sensor that detects the presence or absence of an accelerator operation;
a brake sensor that detects the strength of braking;
an engine control unit that performs an idle stop for temporarily stopping the engine when a predetermined idle stop condition is satisfied;
maintaining the clutch in an engaged state until a predetermined time elapses after a weak braking condition in which the strength of the braking operation is equal to or less than a predetermined strength is established when the host vehicle is idle-stopped and stopped; a transmission control unit that performs restart clutch control to release the clutch when the predetermined time elapses if the accelerator operation is not detected until the predetermined time elapses after the weak brake condition is established;
vehicle equipped with The transmission control unit maintains the clutch in an engaged state without performing the restart clutch control if the strength of the brake operation is greater than a predetermined strength when the vehicle is idle-stopped and stopped. 6. The vehicle according to claim 5 . The transmission control unit delays a request to restart the engine after a predetermined delay time elapses when the weak braking condition is established while the host vehicle is idle-stopped and stopped. 7. The vehicle according to claim 5 , wherein the restart request with restart is transmitted to the engine control unit. When the host vehicle is idle-stopped and decelerated, the transmission control unit determines that a predetermined restart condition for restarting the engine is satisfied and a turbine speed is the rotation speed of the turbine shaft of the torque converter. If the number of revolutions is equal to or less than a predetermined number of revolutions , transmitting the restart request with delay to the engine control unit;
The delay time of the restart request with delay when the host vehicle is idle-stopped and stopped is longer than the delay time of the restart request with delay when the host vehicle is decelerated after idle-stop. A vehicle as claimed in claim 7 which is short.

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