vehicle

Abstract

To properly restart an engine without giving a sense of discomfort to a driver when the engine is stopped by idling stop control and a vehicle is stopped.SOLUTION: In a vehicle of the present disclosure, an acceleration sensor for detecting acceleration in a forward / rearward direction is disabled according to the occurrence of an abnormality, and is also disabled according to turning-off of a start switch of the vehicle by a driver. A control device: recognizes that the start switch is turned off, after a delay time from the turning-off of the start switch; when an engine is stopped by idling stop control and the vehicle is stopped, controls a brake device to apply a braking force to the vehicle in response to the disabling of the acceleration sensor; and determines whether or not to restart the engine at the point of time when a predetermined waiting time longer than the delay time elapses since the acceleration sensor is disabled.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle including a control device that executes engine idling stop control. [Background technology]

[0002] Conventionally, there is known an automatic engine stop device that stops the engine in response to the establishment of a predetermined automatic stop condition, and then restarts the engine when predetermined restart conditions, including at least a condition related to the inclination angle of the road surface, are established (see, for example, Patent Document 1). This automatic stop device retains the detection value of an acceleration sensor after the vehicle has stopped and before the engine has automatically stopped, and after the engine has automatically stopped, determines whether the restart condition is established based on the inclination angle of the road surface calculated from the detection value of the acceleration sensor that has been retained. This eliminates the influence of changes in the detection value of the acceleration sensor due to passengers getting in and out of the vehicle or loading and unloading of luggage after the vehicle has stopped from determining whether the restart condition is established, allowing the engine to be restarted appropriately. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-41457 Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle including the above-described automatic stop device, if the acceleration sensor (detected value) is invalidated due to an abnormality in the acceleration sensor, it becomes impossible to calculate the inclination angle of the road surface, so it is preferable to restart the engine that has been stopped by the idling stop control. However, the acceleration sensor is also invalidated when the start switch (IG switch) of the vehicle is turned off, and if the engine is restarted uniformly when the acceleration sensor is invalidated, the engine start process will be performed immediately after the driver of the vehicle turns off the start switch after the engine has automatically stopped, which may cause the driver to feel uncomfortable.

[0005] Therefore, a main object of the present disclosure is to properly restart the engine without causing discomfort to the driver when the engine is stopped by idling stop control and the vehicle is stopped. [Means for solving the problem]

[0006] The vehicle disclosed herein includes an engine, a brake device, an acceleration sensor that detects acceleration in the longitudinal direction, and a control device that executes idling stop control that stops the engine when predetermined stop conditions are met and starts the engine when predetermined start conditions are met, wherein the acceleration sensor is disabled when an abnormality occurs and when the driver turns off the start switch of the vehicle, and the control device recognizes that the start switch has been turned off after a delay time has passed since the start switch was turned off, and when the engine is stopped by the idling stop control and the vehicle is stopped, controls the brake device to apply braking force to the vehicle in response to the disabling of the acceleration sensor, and determines whether or not to restart the engine when a predetermined waiting time longer than the delay time has elapsed since the acceleration sensor was disabled.

[0007] In the vehicle of the present disclosure, when the engine is stopped by idling stop control and the vehicle is stopped, it is possible to restart the engine appropriately without causing discomfort to the driver. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram showing a vehicle according to the present disclosure. [Figure 2] FIG. 1 is a control block diagram of a vehicle according to the present disclosure. [Figure 3] 3 is a flowchart showing a routine executed by a vehicle control device of the present disclosure. [Figure 4] 4 is a time chart showing the time-dependent changes in the states of the start switch, acceleration sensor, etc. while the routine of FIG. 3 is being executed. DETAILED DESCRIPTION OF THE INVENTION

[0009] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0010] 1 is a schematic diagram showing a vehicle 1 of the present disclosure. The vehicle 1 shown in the figure includes an engine (internal combustion engine) 10 having a plurality of combustion chambers (cylinders), a power transmission device 20 that transmits power from the engine 10 to left and right drive wheels (front wheels) DW, and an electronically controlled hydraulic (fluid pressure) brake device 30. The vehicle 1 may be a front-wheel drive vehicle as shown in the figure, a rear-wheel drive vehicle, or a four-wheel drive vehicle.

[0011] The engine 10 is a gasoline engine that burns a mixture of gasoline (hydrocarbon fuel) and air in multiple combustion chambers and converts the reciprocating motion of pistons resulting from the combustion of the mixture into rotational motion of a crankshaft (not shown). However, the engine 10 may also be a diesel engine or an LPG engine. The engine 10 also includes a starter 11 that outputs cranking torque to the crankshaft to start the engine 10, and an alternator 12 that is driven by the engine 10 to generate electric power.

[0012] The power transmission device 20 includes a starting device 21, a mechanical oil pump 22 driven by power from the engine 10, a transmission 23, a gear mechanism (gear train) 24, a differential gear (differential mechanism) 25, a transmission case 26 that houses these elements, and a hydraulic control device 27. In this embodiment, the starting device 21 is a torque converter that has a torque amplification function, and includes a lock-up clutch and a damper mechanism (both not shown).

[0013] The transmission 23 is a multi-speed (stepped) transmission, for example, with 6 to 10 speeds, including an input member, an output member, multiple planetary gears, and multiple clutches and brakes. However, the transmission 23 may also be a continuously variable transmission (CVT) or a dual-clutch transmission. The transmission 23 changes the speed of power transmitted from the engine 10 to the input member via the starting device 21 (torque converter or lock-up clutch) in multiple stages and outputs the power from the output member to the left and right drive wheels DW via the gear mechanism 24, differential gear 25, and drive shaft DS. The hydraulic control device 27 also includes a valve body with multiple oil passages, multiple regulator valves, multiple linear solenoid valves, etc.

[0014] The hydraulic brake device 30 includes a master cylinder 31, a brake booster 32, and a brake actuator 33. The master cylinder 31 generates master cylinder pressure in response to the driver's depression force acting on a brake pedal 35. The brake booster 32 is a so-called vacuum-type booster including a vacuum chamber, a diaphragm, etc., connected to an intake manifold (not shown) of the engine 10 via piping and a check valve. The brake booster 32 amplifies the depression force applied to the brake pedal 35 by the driver using a force acting on the diaphragm due to the pressure difference between atmospheric pressure and the intake negative pressure of the engine 10. As a result, the master cylinder 31 generates master cylinder pressure in response to the depression force applied by the driver and the negative pressure (intake negative pressure) supplied from the engine 10. The brake booster 32 also includes a negative pressure sensor 34 that detects the pressure in the negative pressure chamber, i.e., the negative pressure in the brake booster 32 (e.g., the pressure difference from atmospheric pressure). In addition, the brake booster 32 may include a sensor that detects the absolute pressure in the negative pressure chamber, and the difference between the absolute pressure detected by the sensor and atmospheric pressure may be calculated as the negative pressure in the brake booster 32.

[0015] The brake actuator 33 adjusts the master cylinder pressure generated by the master cylinder 31 and supplies it to wheel cylinders (not shown) provided on each wheel including the drive wheels DW, thereby applying braking force based on the master cylinder pressure to each wheel via brake pads and brake discs (neither of which are shown). The brake actuator 33 can also adjust the hydraulic pressure in each wheel cylinder so that braking force is applied to each wheel regardless of the driver's depression of the brake pedal 35.

[0016] 2 is a control block diagram of vehicle 1. As shown in the figure, vehicle 1 includes an engine electronic control unit (hereinafter referred to as "EGECU") 100, a transmission electronic control unit (hereinafter referred to as "TMECU") 200, a brake electronic control unit (hereinafter referred to as "brake ECU") 300, an airbag electronic control unit (hereinafter referred to as "ABGECU") 400, and a start / stop electronic control unit (hereinafter referred to as "S&SECU") 500. These ECUs 100, 200, 300, 400, and 500 exchange information with one another via a shared communication line (CAN bus) CB.

[0017] The EGECU 100 includes a microcomputer having a CPU, ROM, RAM, input / output interface, etc. (not shown), and executes control of the intake air amount, fuel injection control, ignition timing control, etc. of the engine 10. Furthermore, when starting the engine 10, the EGECU 100 controls the starter 11 and executes control of the intake air amount, fuel injection control, ignition timing control, etc. The TMECU 200 includes a microcomputer having a CPU, ROM, RAM, input / output interface, etc. (not shown), and controls the hydraulic control device 27 to adjust the hydraulic pressure from the mechanical oil pump 22 and supply it to the starting device 21, the clutches and brakes of the transmission 23, etc.

[0018] The brake ECU 300 includes a microcomputer having a CPU, ROM, RAM, input / output interface, etc. (not shown), and controls the brake actuator 33, etc. based on a master cylinder pressure corresponding to the depression amount of the brake pedal 35. The brake ECU 300 also controls the brake actuator 33, etc. in response to requests from other ECUs, etc., so that braking force is applied to each wheel, regardless of the driver's depression of the brake pedal 35. Furthermore, on uphill or downhill roads, the brake ECU 300 executes hill assist control, in response to requests from other ECUs, etc., so that a braking force greater than the force that balances the road surface gradient is applied to the vehicle 1, regardless of the depression of the brake pedal 35.

[0019] The ABGECU 400 includes a microcomputer having a CPU, ROM, RAM, an input / output interface, etc. (not shown), and controls the operation of a plurality of airbags (not shown) arranged in the passenger compartment based on signals from an acceleration sensor (longitudinal G sensor) 40 that detects the acceleration in the longitudinal direction of the vehicle 1. The ABGECU 400 also transmits an acceleration signal indicating the detection value of the acceleration sensor 40 to the brake ECU 300, which then performs processing such as zero point adjustment on the acceleration signal from the ABGECU 400 and transmits the signal to another ECU such as the S&SECU 500. The brake ECU 300 also determines whether or not there is an abnormality in the acceleration sensor 40 based on the acceleration signal from the ABGECU 400, and if it determines that an abnormality has occurred in the acceleration sensor 40, it disables the acceleration sensor 40 and transmits a signal indicating this to another ECU such as the S&SECU 500. In addition, when the driver of vehicle 1 turns off the start switch SS (IG switch) for starting the system and the power supply is stopped, so that the acceleration signal is no longer output from ABGECU400, the brake ECU300 disables the acceleration sensor 40 and sends a signal indicating this to other ECUs such as S&SECU500.

[0020] The S&SECU 500 includes a microcomputer having a CPU, ROM, RAM, an input / output interface, etc. (not shown), and executes idling stop control to stop the engine 10 when a predetermined stop condition is met and start the engine 10 when a predetermined start condition is met. That is, the S&SECU 500 causes the EGECU 100 to stop the operation of the engine 10 while the vehicle 1 is decelerating or stopped based on signals from the brake switch 36 and the accelerator pedal position sensor 39, and causes the EGECU 100 to restart the engine 10 in response to a start request from the driver for the vehicle 1, such as releasing the brake pedal 35. In this embodiment, the S&SECU 500 calculates the road gradient (inclination angle) of the road surface on which the vehicle 1 is traveling based on the acceleration signal from the brake ECU 300, i.e., the detection value of the acceleration sensor 40, and determines whether or not there is an abnormality in the negative pressure sensor 34 of the brake booster 32. Then, while the engine 10 is stopped due to the idling stop control, the S&SECU 500 instructs the brake ECU 300 to execute the hill assist control in accordance with the road surface gradient and the state of the negative pressure sensor 34, and also instructs the EGECU 100 to restart the engine 10.

[0021] Furthermore, as shown in FIG. 2 , the S&SECU 500 has a terminal T to which a voltage is supplied via the start switch SS when the start switch SS is turned on. The S&SECU 500 determines whether the start switch SS is turned on or off based on the voltage at terminal T. The S&SECU 500 also has a capacitor C that is charged by the voltage supplied from the start switch SS to terminal T. When the driver turns off the start switch SS, the voltage at terminal T decreases as capacitor C discharges. Therefore, the S&SECU 500 recognizes that the start switch SS has been turned off only after a delay time corresponding to the discharge time of capacitor C has elapsed since the driver actually turned off the start switch SS. As a result, even if the voltage supply from the start switch SS is temporarily interrupted due to a momentary interruption caused by vibration or the like, the S&SECU 500 does not mistakenly recognize that the start switch SS has been turned off, and it is possible to continue executing idling stop control and the like. In this embodiment, the discharge time of capacitor C is, for example, 50-100 msec. In this embodiment, the start switch SS of the vehicle 1 is a push switch that is allowed to be operated only when the shift range is in the parking range.

[0022] 3 is a flowchart showing a routine that is repeatedly executed by the S&SECU 500 at predetermined time intervals (short time intervals) when the engine 10 is stopped by the idling stop control during deceleration or after stopping of the vehicle 1, and the driver switches the shift range to the parking range while the vehicle 1 is stopped. When the timing to execute the routine of FIG. 3 arrives, the S&SECU 500 acquires information necessary for control, such as an acceleration signal from the brake ECU 300, a signal indicating the result of an abnormality determination for the acceleration sensor 40, and the result of an abnormality determination for the negative pressure sensor 34 of the brake booster 32 (step S100).

[0023] Next, the S&SECU 500 determines whether the acceleration sensor 40 is valid based on the signal from the brake ECU 300 (step S110). If the acceleration sensor 40 is valid (step S110: YES), the S&SECU 500 determines whether the negative pressure sensor 34 of the brake booster 32 is normal based on the result of the abnormality determination for the negative pressure sensor 34 (step S120). If the negative pressure sensor 34 is normal (step S120: YES), the S&SECU 500 calculates the road gradient (inclination angle) of the road surface on which the vehicle 1 is stopped based on the value of the acceleration signal acquired in step S100 (step S130), and determines whether the absolute value of the calculated road gradient is equal to or greater than a predetermined threshold value (step S140). If the absolute value of the road surface gradient is less than the threshold value and the road surface gradient on which the vehicle 1 is stopped is relatively gentle (step S140: NO), the S&SECU 500 determines that there is no need to restart the engine 10 and temporarily terminates the routine of Figure 3 at that point.

[0024] On the other hand, if the absolute value of the road surface gradient is equal to or greater than the threshold value and the gradient of the road surface on which the vehicle 1 is stopped is relatively steep (step S140: YES), the S&SECU 500 determines that the negative pressure in the brake booster 32 may decrease (negative pressure is required) and transmits a hill assist command to the brake ECU 300 so that the brake actuator 33 applies a braking force to the vehicle 1 that is greater than the force that balances the road surface gradient through hill assist control (step S150). Furthermore, after transmitting the hill assist command, the S&SECU 500 waits for a predetermined waiting time tref (e.g., 150-200 msec) (step S160). The waiting time tref is pre-adjusted so that it is longer than the delay time (i.e., the discharge time of the capacitor C) from when the start switch SS is actually turned off by the driver until the S&SECU 500 recognizes that the start switch SS has been turned off, and is shorter than the time it takes for the negative pressure (absolute value) in the brake booster 32 to change from its maximum value to zero.

[0025] When the standby time tref has elapsed after the transmission of the hill assist command, the S&SECU 500 determines whether the start switch SS is on or not based on the voltage at the terminal T (step S170). If the start switch SS is on (step S170: YES), the S&SECU 500 transmits an engine start command to the EGECU 100 to restart the engine 10 (step S180) and temporarily ends the routine in Fig. 3. On the other hand, if the start switch SS is off (step S170: NO), the S&SECU 500 temporarily ends the routine in Fig. 3 without restarting the engine 10.

[0026] Furthermore, when it is determined based on the signal from the brake ECU 300 that the acceleration sensor 40 is disabled (step S110: NO), the S&SECU 500 executes the processing from step S150 onward described above. That is, when the engine 10 is stopped by the idling stop control, the driver switches the shift range to the parking range while the vehicle 1 is stopped, and the brake ECU 300 disables the acceleration sensor 40, the S&SECU 500 transmits a hill assist command to the brake ECU 300 so that the hydraulic brake device 30 applies braking force to the vehicle 1 (step S150), and determines whether to restart the engine 10 based on the state of the start switch SS when a waiting time tref longer than the delay time has elapsed since the acceleration sensor 40 was disabled (steps S160, S170).

[0027] Similarly, when it is determined that an abnormality has occurred in the negative pressure sensor 34 of the brake booster 32 (step S120: NO), the S&SECU 500 executes the processing from step S150 onward described above. That is, when the engine 10 is stopped by the idling stop control, the driver switches the shift range to the parking range while the vehicle 1 is stopped, and an abnormality has occurred in the negative pressure sensor 34 of the brake booster 32, the S&SECU 500 transmits a hill assist command to the brake ECU 300 so that braking force is applied to the vehicle 1 from the hydraulic brake device 30 (step S150), and determines whether to restart the engine 10 based on the state of the start switch SS when a waiting time tref longer than the delay time has elapsed since the acceleration sensor 40 was disabled (steps S160, S170).

[0028] As described above, in the vehicle 1, the acceleration sensor 40 (its detection value), which detects acceleration in the longitudinal direction, is disabled in response to the occurrence of an abnormality and in response to the driver turning off the start switch SS. The S&SECU 500 recognizes that the start switch SS has been turned off after a delay time has elapsed since the start switch SS was turned off. Furthermore, when the engine 10 is stopped by idling stop control and the driver switches the shift range to the parking range while the vehicle 1 is stationary, the S&SECU 500 controls the hydraulic brake device 30 in cooperation with the brake ECU 300 to apply a braking force to the vehicle 1 in response to the disabling of the acceleration sensor 40 (step S110: NO), and determines whether to restart the engine 10 when a waiting time tref longer than the delay time has elapsed since the acceleration sensor 40 was disabled (steps S160 and S170).

[0029] 4, when the acceleration sensor 40 is disabled as a result of the driver turning off the start switch SS (time t2 in FIG. 4), the S&SECU 500 recognizes that the start switch SS is turned off (step S170: NO) at the point in time when a waiting time tref longer than the delay time has elapsed since the acceleration sensor 40 was disabled, that is, at the timing when it is determined in step S170 whether or not to restart the engine 10 (time t3 in FIG. 2). Therefore, when the engine 10 is stopped by the idling stop control, the driver switches the shift range to the parking range while the vehicle 1 is stopped, and the driver turns off the start switch SS, as shown by the solid line in FIG. 4, no engine start command is transmitted from the S&SECU 500 to the EGECU 100, and the engine 10 is not restarted.

[0030] Furthermore, when an abnormality occurs in the acceleration sensor 40 while the start switch SS is not turned off by the driver (see the two-dot chain line in FIG. 4), the hydraulic brake device 30 applies a braking force to the vehicle 1 in response to the disabling of the acceleration sensor 40, and then, after the waiting time tref has elapsed since the disabling of the acceleration sensor 40, the engine 10 can be started while preventing the vehicle 1 from rolling down (step S180, time t4 in FIG. 4). As a result, in the vehicle 1, when the engine 10 is stopped by the idling stop control and the driver switches the shift range to the parking range while the vehicle 1 is stopped, the engine 10 can be restarted appropriately without causing any discomfort to the driver.

[0031] Furthermore, when the engine 10 is stopped by idling stop control and the driver switches the shift range to the parking range while the vehicle 1 is stopped, in response to the occurrence of an abnormality in the vacuum sensor 34 (step S120: NO), the S&SECU 500 controls the hydraulic brake device 30 in cooperation with the brake ECU 300 to apply a braking force to the vehicle 1 (step S150). Furthermore, when the acceleration sensor 40 is enabled and the vacuum sensor 34 is normal, the S&SECU 500 calculates the road surface gradient based on the acceleration signal from the brake ECU 300, i.e., the detection value of the acceleration sensor 40 (step S130). Furthermore, when the calculated road surface gradient (absolute value) is equal to or greater than a threshold value (predetermined gradient) (step S140: YES), the S&SECU 500 determines that the vacuum in the brake booster 32 is reduced (vacuum is required), and controls the hydraulic brake device 30 in cooperation with the brake ECU 300 to apply a braking force to the vehicle 1 (step S150). Then, when the waiting time tref has elapsed since an abnormality occurred in the negative pressure sensor 34 (step S120: NO) or the negative pressure in the brake booster 32 decreased (step S140: YES), the S&SECU 500 determines whether or not to restart the engine 10 based on the voltage at terminal T (step S170).

[0032] As a result, when an abnormality occurs in the vacuum sensor 34 or the vacuum in the brake booster 32 decreases, after the hydraulic brake device 30 applies braking force to the vehicle 1, it becomes possible to start the engine 10 while suppressing the vehicle 1 from rolling down, etc., in response to the elapse of the waiting time tref since the occurrence of the abnormality in the vacuum sensor 34 or the decrease in the vacuum in the brake booster 32. Note that in the vehicle 1, the vacuum in the brake booster 32 is considered to have decreased when the road surface gradient (absolute value) is equal to or greater than a threshold value, but this is not limited thereto. That is, the vacuum from the vacuum sensor 34 may be acquired in step S130 of FIG. 3, and it may be determined in step S140 that the vacuum in the brake booster 32 has decreased when the vacuum (absolute value) is equal to or less than a threshold value.

[0033] Furthermore, S&SECU 500 includes a terminal T to which a voltage is supplied via S&SECU 500 when start switch SS is turned on, and a capacitor C that is charged by the voltage supplied to terminal T. This effectively prevents S&SECU 500 from erroneously recognizing that start switch SS has been turned off when a momentary power interruption or the like occurs, and also makes it possible to properly restart engine 10 without causing discomfort to the driver when engine 10 is stopped by idling stop control and the driver switches the shift range to the parking range while vehicle 1 is stopped.

[0034] Furthermore, in the vehicle 1, the waiting time tref is set to be longer than the discharge time of the capacitor C and shorter than the time it takes for the negative pressure in the brake booster 32 to decrease from its maximum value to zero. This allows the S&SECU 500 to reliably recognize that the start switch SS has been turned off during the period from when the acceleration sensor 40 is disabled until it is determined in step S170 whether or not the engine 10 can be restarted, when the driver turns off the start switch SS. Furthermore, when an abnormality in the acceleration sensor 40 actually occurs, the engine 10 can be restarted with braking force being applied to the vehicle 1 from the hydraulic brake device 30, and negative pressure can be supplied from the engine 10 to the brake booster 32, allowing the driver to depress the brake pedal 35.

[0035] The start switch SS of the vehicle 1 is not limited to a push switch that can be operated only when the shift range is in the parking range, but may be a key switch that can be operated even when the shift position is in the parking position. If the start switch SS is a key switch, the routine in Fig. 3 may be executed when the engine 10 is stopped by idling stop control while the vehicle 1 is decelerating or after being stopped, and when the vehicle 1 is stopped.

[0036] As described above, the vehicle of the present disclosure is a vehicle (1) including an engine (10), a brake device (30), an acceleration sensor (40) that detects acceleration in the longitudinal direction, and a control device (500) that executes idling stop control to stop the engine (10) in response to the establishment of a predetermined stop condition and to start the engine (10) in response to the establishment of a predetermined start condition, in which the acceleration sensor (40) is disabled in response to the occurrence of an abnormality and is also disabled in response to the start switch (SS) of the vehicle (1) being turned off by the driver, and the control device (500) controls the start switch (SS) to The control unit 10 recognizes that the start switch (SS) has been turned off after a delay time has elapsed since the start switch (SS) was turned off, and when the engine (10) is stopped by the idling stop control and the vehicle (1) is stopped, the control unit 10 controls the brake device (30) to apply a braking force to the vehicle (1) in response to the disabling of the acceleration sensor (40) (step S110: NO) (step S150), and determines whether or not to restart the engine (10) when a predetermined waiting time (tref) longer than the delay time has elapsed since the acceleration sensor (40) was disabled (steps S160, S170).

[0037] In the vehicle disclosed herein, the acceleration sensor (detected value) detecting longitudinal acceleration is disabled when an abnormality occurs and when the driver turns off the vehicle's start switch. The control device recognizes that the start switch has been turned off after a delay time has elapsed since the start switch was turned off. When the engine is stopped by idling stop control and the vehicle is stopped, the control device controls the brake device to apply braking force to the vehicle in response to the disabling of the acceleration sensor, and determines whether to restart the engine when a waiting time longer than the delay time has elapsed since the acceleration sensor was disabled. Thus, when the acceleration sensor is disabled by the driver turning off the start switch, the control device recognizes that the start switch has been turned off at the time when a waiting time longer than the delay time has elapsed since the acceleration sensor was disabled, i.e., when it is determined whether to restart the engine, and therefore the engine is not restarted. Furthermore, when an abnormality occurs in the acceleration sensor, the brake device applies braking force to the vehicle in response to the disabling of the acceleration sensor, and then the engine can be started while preventing the vehicle from rolling over, etc., after a waiting time has elapsed since the acceleration sensor was disabled. As a result, in the vehicle of the present disclosure, when the engine is stopped by idling stop control and the vehicle is stopped, it is possible to restart the engine appropriately so as not to cause discomfort to the driver.

[0038] The control device (500) may also include a terminal (T) to which a voltage is supplied via the start switch (SS) when the start switch (SS) is turned on, and a capacitor (C) that is charged by the voltage supplied to the terminal (T).

[0039] This effectively prevents the control device from erroneously recognizing that the start switch has been turned off when a momentary power interruption or the like occurs, and when the engine is stopped by idling stop control and the vehicle is stopped, it becomes possible to properly restart the engine without causing discomfort to the driver.

[0040] Furthermore, the braking device (30) may include a brake booster (32) to which negative pressure is supplied from the engine (10), and the waiting time (tref) may be longer than the discharge time of the capacitor (c) and shorter than the time it takes for the negative pressure in the brake booster (32) to decrease from its maximum value to zero.

[0041] This makes it possible for the control device to reliably recognize that the start switch has been turned off during the period from when the acceleration sensor is disabled until when it is determined whether the engine can be restarted, when the start switch is turned off by the driver.

[0042] Furthermore, the brake device (30) may include a negative pressure sensor (34) that detects the negative pressure in the brake booster (32), and when the engine (10) is stopped by the idling stop control and the vehicle (1) is stopped, the control device (500) may control the brake device (30) to apply a braking force to the vehicle (1) (step S150) in response to the occurrence of an abnormality in the negative pressure sensor (34) or the decrease in the negative pressure in the brake booster (32) (step S120: NO, step S140: YES), and may determine whether or not to restart the engine (10) when the waiting time (tref) has elapsed since the occurrence of the abnormality in the negative pressure sensor (34) or the decrease in the negative pressure in the brake booster (32) (steps S160, S170).

[0043] This makes it possible to start the engine while preventing the vehicle from rolling over, etc., after the brake device applies braking force to the vehicle when an abnormality occurs in the negative pressure sensor or the negative pressure in the brake booster drops, and then, once a waiting time has elapsed since the occurrence of the abnormality in the negative pressure sensor or the drop in negative pressure in the brake booster, the engine can be started while preventing the vehicle from rolling over, etc.

[0044] Furthermore, when the engine (10) is stopped by the idling stop control and the vehicle (1) is stopped, the control device (500) may calculate a road surface gradient based on the detection value of the acceleration sensor (40) (step S130), and when the calculated road surface gradient is equal to or greater than a predetermined gradient (step S140: YES), the control device (500) may determine that the negative pressure in the brake booster (32) is decreasing and control the brake device (30) to apply a braking force to the vehicle (1) (step S150).

[0045] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present disclosure. Furthermore, the above-described embodiment is merely a specific form of the invention described in the Summary of the Invention, and does not limit the elements of the invention described in the Summary of the Invention. [Industrial Applicability]

[0046] The invention of the present disclosure can be used in the vehicle manufacturing industry and the like. [Explanation of symbols]

[0047] 1 vehicle, 10 engine, 11 starter, 20 power transmission device, 30 hydraulic brake device, 32 brake booster, 33 brake actuator, 34 vacuum sensor, 35 brake pedal, 36 brake switch, 40 acceleration sensor, 100 engine electronic control unit (EGECU), 300 brake electronic control unit (brake ECU), 400 airbag electronic control unit (ABGECU), 500 start-stop electronic control unit (S&SECU), C capacitor, SS start switch, T terminal.

Claims

1. A vehicle including an engine, a brake device, an acceleration sensor that detects acceleration in a longitudinal direction, and a control device that executes idling stop control to stop the engine when a predetermined stop condition is satisfied and to start the engine when a predetermined start condition is satisfied, The acceleration sensor is disabled in response to the occurrence of an abnormality, and is also disabled in response to the driver turning off a start switch of the vehicle, The control device recognizes that the start switch has been turned off after a delay time has passed since the start switch was turned off, and when the engine has been stopped by the idling stop control and the vehicle is stationary, controls the brake device to apply a braking force to the vehicle in accordance with disabling of the acceleration sensor, and determines whether or not to restart the engine when a predetermined waiting time that is longer than the delay time has elapsed since the acceleration sensor was disabled.

2. 2. The vehicle according to claim 1, The control device includes a terminal to which a voltage is supplied via the start switch when the start switch is turned on, and a capacitor that is charged by the voltage supplied to the terminal.

3. 3. The vehicle according to claim 2, the braking device includes a brake booster to which negative pressure is supplied from the engine, The waiting time is longer than the discharge time of the capacitor and shorter than the time it takes for the negative pressure in the brake booster to decrease from its maximum value to zero.

4. 4. The vehicle according to claim 3, the brake device includes a negative pressure sensor that detects the negative pressure in the brake booster, The control device controls the brake device to apply braking force to the vehicle in response to an abnormality in the vacuum sensor or a decrease in the vacuum in the brake booster when the engine is stopped by the idling stop control and the vehicle is stopped, and determines whether or not to restart the engine when the waiting time has elapsed since the abnormality in the vacuum sensor or the decrease in the vacuum in the brake booster.

5. 5. The vehicle according to claim 3 or 4, The control device calculates the road surface gradient based on the detection value of the acceleration sensor when the engine is stopped by the idling stop control and the vehicle is stopped, and when the calculated road surface gradient is equal to or greater than a predetermined gradient, controls the brake device to apply braking force to the vehicle, assuming that the negative pressure in the brake booster is decreasing.

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