JP4039434B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and more specifically, control for stopping a drive source while the vehicle is stopped in order to reduce energy consumption and combustion gas (hereinafter referred to as drive source stop control and The present invention relates to a vehicle control device including a drive source control device.

  An example of a vehicle control device including a drive source control device that performs the drive source stop control described above is described in the specification of Japanese Patent Application No. 11-57124 filed earlier by the applicant of the present application and unpublished. . The vehicle control device described in the above specification is (a) a drive source control device that automatically stops and automatically restarts an engine as a drive source when a predetermined engine stop condition is satisfied, and (b) a braking force control device that controls the braking force while the vehicle is stopped. In this vehicle control device, the engine is restarted when the operation state of the shift operation device is changed from the non-drive state to the drive state and the brake operation by the driver is released.

  An object of the present invention is to provide a vehicle control device including a drive source control device that performs drive source stop control, such as quickly starting the vehicle or starting the vehicle in a state that well matches the driver's intention. It is to improve the startability of.

Means and effects for solving the problems

The vehicle control device according to claim 1 is (i) a drive source control that automatically stops and automatically restarts the drive source when a predetermined drive source stop condition is satisfied while the vehicle is stopped. And (ii) a braking force control device that controls a braking force applied to the vehicle, wherein the braking force control device is restarted by the driving source control device. When the driver gives an instruction to start the vehicle, the braking force reduction control unit corresponding to the shift operation state reduces the braking force in a pattern corresponding to the type of the shift operation state of the shift operation device of the vehicle. It is supposed to include.
In the vehicle control device described in this section, the braking force is reduced in a pattern corresponding to the changed type of driving state of the shift operation device, so that the vehicle is started in a state that matches the driver's intention. In a vehicle control apparatus in which drive source stop control is performed, it is not essential that the braking force reduction control is automatically performed. For example, if the braking force is reduced in accordance with the brake release operation of the driver as in the case where the brake is operated by the hydraulic pressure of the hydraulic fluid supplied from the master cylinder, the vehicle is started according to the brake release operation. be able to. On the other hand, if the braking force is automatically reduced in a pattern according to the type of drive position, the startability can be improved.
The braking force can be reduced when an operation for instructing the start is performed. It may be decreased immediately after the start instruction operation, may be decreased along with the start instruction operation, or may be decreased after a predetermined set time after the start instruction operation is performed. For example, when a brake release operation is performed as a start instruction operation, if the braking force is decreased after a set time has elapsed after the brake operation is released, the vehicle can be prevented from dropping when starting on a slope. Further, when an accelerator operation is performed as a start instruction operation, the vehicle can be started quickly if it is decreased immediately after the accelerator operation or with the accelerator operation. In this way, if the braking force starts to decrease from the start time according to the type of the start instruction operation, the startability of the vehicle can be improved, and in addition, the pattern decreases according to the driving state of the shift operation device. By doing so, the startability can be further improved. The braking force can also be reduced as the drive source is restarted.
The operation state of the shift operation device is changed by the driver's shift operation. For example, the driver changes to a different type of driving state depending on whether he wants to start suddenly with a large driving force or when he wants to start slowly with a small driving force. Therefore, based on the type of driving state after the shift, the start state intended by the driver can be acquired, and if the braking force is reduced in a pattern according to the type of driving state after the shift, The vehicle can be started in a state that matches the intention.
The braking force may be decreased at a gradient according to the type of the shift operation state as described in claim 2, or the start time according to the type of the shift operation state as described in claim 3. Or can be reduced.
The vehicle control apparatus according to claim 4, wherein the transmission unit that changes the output speed of the output shaft of the drive source and outputs the change, and the transmission unit controls the speed of the output shaft of the drive source, thereby changing the rotation speed of the output shaft of the drive source. A drive transmission control device including a transmission control unit that sets a speed ratio, which is a value divided by the number of rotations of the output shaft of the shift operation device, to a magnitude corresponding to the shift operation state of the shift operation device. When the gear ratio corresponding to the shift operation state is smaller than a preset setting ratio, the power reduction control unit starts to reduce the braking force after the control of the gear shift unit in the drive transmission control device is completed. When the speed ratio is larger than the set ratio, a braking force reduction start portion that starts the reduction of the braking force before the control of the speed change portion in the drive transmission control device is completed is included.
In the vehicle control device described in this section, the braking force is reduced from the start timing determined according to the type of shift operation state. For example, when the shift operation state is drive “D”, low “L”, and reverse “R”, it corresponds to a case where the gear ratio is large, and when it is second “2nd”, it corresponds to a case where it is small. Therefore, in the case of the drive “D”, low “L”, and reverse “R”, the braking force starts to decrease before the end of the control of the transmission, and in the second “2nd”, after the end. Decrease will be started, and the decrease start time will be delayed. As a result, when the speed is changed to the second “2nd”, the braking force can be decreased slowly and the vehicle can be started slowly.
6. The vehicle control device according to claim 5, wherein the shift operation state corresponding braking force reduction control unit starts the reduction of the braking force from a time determined according to the type of operation instructing the driver to start. It is supposed to include.
In the vehicle control device described in this section, the braking force is decreased from the start timing determined according to the type of operation instructing start. Thereby, the startability of the vehicle can be improved.
The vehicle control device according to claim 6, wherein when the accelerator operation is performed as an operation instructing the driver to start, the braking force control unit corresponding to the shift operation state responds to the accelerator operation. And when the brake release operation is performed as an operation for instructing the driver to start, the brake force reduction means is started after a set time has elapsed after the brake operation is released. .
According to a seventh aspect of the present invention, in the vehicle control device according to the seventh aspect, the braking force control device is configured such that the braking force is applied to the vehicle, such as a road surface gradient and a load load, while the drive source is stopped by the drive source control device. It includes a driving power source stop time braking force control unit that controls the vehicle to a size suitable for keeping the vehicle in a stopped state in accordance with the environment.
In the vehicle control device described in this section, the braking force is controlled to a magnitude suitable for keeping the vehicle in a stopped state while the drive source is stopped. Therefore, the vehicle can be reliably kept in a stopped state while the drive source is stopped. On the other hand, even if the braking force is controlled to the maximum magnitude that can be controlled by the braking force control device, the vehicle can be kept in a stopped state. However, in that case, when starting the vehicle, it takes a long time to reduce the braking force until the braking force becomes zero, and the vehicle cannot start quickly. Therefore, if the braking force is controlled to an appropriate magnitude, it is possible to avoid an increase in the time required to reduce the braking force until it becomes zero, and the startability can be improved.
The moving force is a force generated based on the environment in which the vehicle is placed, such as a road surface gradient and a loaded load, and is a force mainly generated by gravity. Gravity applied to the vehicle increases as the road surface gradient increases, and increases as the loaded load increases. Therefore, the braking force required to keep the vehicle stopped is increased.
As will be described with reference to FIG. 7 in the following [Embodiment of the invention] section, the road surface gradient and the loaded load are, for example, output signals of vehicle height sensors provided on each of the four wheels (the vehicle body side member in the vehicle). Relative displacement between the vehicle and the wheel side member) and an output signal of the gradient sensor (inclination with respect to the horizon of the vehicle). The road surface gradient can be obtained based on the inclination angle θ with respect to the road surface of the vehicle body obtained based on the output signal of the vehicle height sensor and the inclination angle φ with respect to the horizontal line of the vehicle. It can be determined based on the signal and the road surface gradient.

Related invention

Hereinafter, matters related to the present invention will be described.
(1) A drive source control device that automatically stops and automatically restarts a drive source when a predetermined drive source stop condition is satisfied while the vehicle is stopped,
A drive source control device comprising a shift restart unit that restarts the drive source when the operation state of the shift operation device of the vehicle is changed from a non-drive state to a drive state.
In the drive source control device described in this section, the drive source is restarted when the operation state of the shift operation device is changed from the non-drive state to the drive state after the drive source is automatically stopped. Thereafter, when the driver tries to start the vehicle, the vehicle can be started quickly because the drive source is already in an operating state.
“While the vehicle is stopped” represents a period from the moment when the vehicle stops to immediately before starting. Therefore, the drive source stop condition may be satisfied at the moment when the vehicle stops, and the drive source may be stopped. The drive source may be an internal combustion engine such as an engine, an electrical drive source including an electric motor, or may include both an internal combustion engine and an electrical drive source.
If the drive source is stopped while the vehicle is stopped, energy consumption can be reduced regardless of the type of the drive source. Further, when the drive source is an engine, it is possible to avoid wasteful combustion gas discharge. However, when the driver tries to start, if the drive source is in a stopped state, the driver cannot start immediately. Therefore, the drive source is started in response to the start preparation operation, that is, the operation to change the shift operation device to the drive state. As a result, the operation for instructing the start, for example, the brake release operation, the accelerator When a switch for instructing operation or starting is operated, the drive source is already in an operating state, and the vehicle can be started quickly.
In the shift operation device, the shift operation state is changed according to the operation of the operation member, and the shift state is determined corresponding to the shift operation state. The shift state includes a drive state and a non-drive state. The drive state includes, for example, a drive “D”, a low “L”, a second “2nd”, a reverse “R”, and the non-drive state. For example, there are neutral “N”, parking “P”, and the like. As the operation member, various types such as a lever type and a push button type can be adopted. In any case, when the shift state is changed by changing the position of the operation member, or when the operation member is provided corresponding to each of the plurality of shift states, Increases the number of operations of the operation member when it is changed by switching one from the non-operation state to the operation state, or when the operation member is shifted up or down one step at a time. There is a case to let you.
(2) In the drive source control device, after the drive source is restarted by the shift restart unit, an operation for instructing start of the vehicle is performed by the driver within a predetermined set time. The drive source control device according to item (1), further including a drive force reduction unit that reduces the drive force of the drive source when there is no drive power.
After the driving source is restarted, the driving force of the driving source is reduced when an operation for instructing the start is not performed within a predetermined set time. For this reason, it is possible to reduce energy consumption and to avoid wasteful combustion gas discharge.
As described above, the drive source is started with the start preparation operation, that is, prior to the start instruction operation. In other words, it is started in anticipation that a start instruction operation will be performed in the near future. Therefore, even if the engine is started, the start instruction operation may not be performed within the set time. In this case, the driving force is reduced. The driving force may be reduced to 0 or may be reduced to a predetermined setting driving force greater than 0. Moreover, when decreasing, you may reduce in steps or continuously with the elapsed time from the time of restart. When the driving force is reduced to zero, the energy consumption can be particularly reduced or zero. When the driving force is set to 0, there are cases where the operating state of the driving source is maintained and no load is applied, and when the driving force is stopped, energy consumption is particularly reduced in the former. And in the latter case it can be zero. On the other hand, when the driving force is reduced to a set driving force larger than 0, it is possible to start quickly according to the starting operation as compared with the case where the driving force is reduced to 0. Note that the value can be set to 0 only when the possibility that a start instruction operation is performed in the near future is very low, for example, when the shift operation device is changed to the non-driven state again.
(3) The drive source control device according to (1) or (2),
And a braking force control device that controls a braking force applied to the vehicle.
The drive source control device is preferably used in combination with a braking force control device that controls the braking force for braking the vehicle. For example, when the driving source is stopped on a slope, if the amount of brake operation is relaxed by the driver, the vehicle is moved based on gravity. Further, when the braking force corresponding to the driver's brake operation amount is smaller than the driving force when the driving source is restarted, the vehicle may start at the time of restarting. Further, in an automatic vehicle that includes an engine as a driving source and includes a torque converter that transmits the driving force of the engine to the transmission by a fluid, the engine is in an operating state even when the vehicle is stopped, and a shift is performed. When the operating device is in the driving state, the driving force of the engine is transmitted to the driving wheels via the torque converter and transmission, and creep torque is generated. However, no creep torque is produced when the engine is stopped. Therefore, when the vehicle is stopped on a slope and the driver performs a braking operation in anticipation of creep torque, the braking force corresponding to the amount of braking operation by the driver is insufficient, and the vehicle is lowered by gravity. there is a possibility. In such a case, if the braking force can be controlled, the movement of the vehicle can be suppressed, which is effective. In addition, if the braking force can be controlled to be reduced when the vehicle is started, the vehicle can be started smoothly, which is effective.
The braking force control device is configured to generate a hydraulic braking force generated by pressing a friction member against a brake rotating body that is rotated integrally with a vehicle wheel by the hydraulic pressure of the brake cylinder and frictionally engaging the brake rotating body. An electric braking force control device that controls the electric braking force, or an electric braking force that is generated by pressing the friction member against the driving force of the electric motor by controlling the operating state of the electric motor. Or a dynamic braking force control device. In the latter electric braking force control device, the electric braking force can be increased, decreased, or held by controlling the operating state of the electric motor. Further, the former hydraulic braking force control device generates, for example, (a) (i) a hydraulic pressure corresponding to the brake cylinder and the amount of brake operation by the driver, as described in the section of [Embodiment of the invention]. A hydraulic pressure control valve provided between the master cylinder and the hydraulic cylinder for controlling the hydraulic pressure of the brake cylinder to a hydraulic pressure corresponding to the supplied electric energy. (Ii) a hydraulic pressure control valve device including an electric energy control unit that controls electric energy supplied to the hydraulic pressure control valve; and (b) (iii) a pump that pressurizes the hydraulic fluid and supplies the hydraulic fluid to the brake cylinder. , (Iv) includes at least one of a motor control unit that controls an electric motor that drives the pump, and (v) a hydraulic pressurizing device that includes a hydraulic fluid supply device that supplies hydraulic fluid to the pump. Can do. When the power pressurization device is in the non-operating state, the hydraulic pressure of the brake cylinder can be maintained by setting the hydraulic pressure control valve to a cutoff state in which the brake cylinder is shut off from the master cylinder. Further, if the communication state is established in the non-brake operation state, the hydraulic fluid can flow out from the brake cylinder to the master cylinder and the pressure can be reduced. If the brake cylinder hydraulic pressure is reduced only when the brake operation is released, a hydraulic pressure control valve may be provided between the master cylinder and the hydraulic cylinder. On the other hand, the brake cylinder hydraulic pressure can be made larger than the master cylinder hydraulic pressure by shutting off the brake cylinder from the master cylinder by the hydraulic pressure control valve and operating the power booster. The hydraulic fluid supply device may supply the hydraulic fluid of the reservoir (low pressure source) to the pump or the hydraulic fluid of the master cylinder, but supplies the hydraulic fluid of the master cylinder. If so, the required energy can be reduced when the hydraulic pressure of the brake cylinder is controlled to the same magnitude.
(4) The braking force control device controls the braking force in at least one of a case where the driving source is stopped by the driving source control device, a case where the driving source is restarted, and a time when the vehicle starts. The vehicle control device according to item (3).
If the braking force is controlled during the drive source stop control, the vehicle can be reliably kept in a stopped state when the drive source is stopped or restarted. Examples of braking force control devices that control braking force when the drive source is stopped are shown in items (12), (14), and (19), and examples of devices that are controlled at restart are given in item (7). Examples of devices that are controlled when starting are shown in items (9) to (11), (15), (16), and (17).
(5) The vehicle control device is provided with a driving / braking force comparison device that compares the driving force when the driving source is restarted by the driving source control device with the braking force of the braking force control device. The vehicle control device according to item (3) or (4),
In the vehicle control device described in this section, the driving force and the braking force when restarted are compared. The driving force when restarted can be estimated based on, for example, the shifted position of the shift operating device. In this case, the driving force and the braking force can be compared before restarting. it can. If the driving force and the braking force are compared, for example, it can be determined whether or not the vehicle can be kept stopped when the driving source is restarted.
(6) The vehicle control device is provided with a warning device that issues a warning when the driving force is greater than the braking force as a result of the comparison by the driving / braking force comparison device. The vehicle control device described.
If the driving force is greater than the braking force, a warning is issued because the vehicle may be moved during restart. If a warning is issued and the driver increases the amount of brake operation, and the braking force is greater than the driving force, the vehicle can be kept stopped during restart.
(7) When the braking force control device increases the braking force when the driving force is greater than the braking force as a result of comparison by the driving / braking force comparison device, the braking force at the time of restarting the drive source The vehicle control device according to any one of (5) or (6), including an increase control unit.
If the braking force is made larger than the driving force that is estimated to be output when the drive source is restarted, the vehicle can be reliably secured when the drive source is restarted without increasing the brake operation amount. Can be stopped.
(8) When the driving source control device restarts the driving source when the braking force is greater than the driving force as a result of the comparison by the driving / braking force comparison device, The vehicle control device according to any one of (5) to (7).
In the vehicle control device described in this section, the driving source is restarted when the braking force is greater than the driving force estimated to be generated at the time of restart. Can be stopped.
Here, it can be considered that the braking force being larger than the driving force is one requirement for the drive source restart condition to be satisfied, but it can also be considered separately from the drive source restart condition. One example of the latter is when the drive source restart condition is satisfied, the control by the braking force control device is performed first, and the drive source is restarted when the braking force is greater than the drive force. It is.
(9) The braking force control device includes a braking force reduction control unit that reduces the braking force in a pattern according to the type of the changed driving state of the shift operation device. The vehicle control device according to any one of the above.
For example, the braking force may be decreased with a gradient according to the type of driving state as described in (10), or may be decreased from the start time determined according to the type as described in (11). can do.
(10) The vehicle control device according to (9), wherein the braking force reduction control unit includes a shift operation state corresponding gradient reduction control unit that reduces the braking force with a gradient according to the type of the drive position.
In the vehicle control device described in this section, the braking force is reduced with a gradient corresponding to the type of drive state after the shift operation device is changed.
(11) The vehicle control device shifts and outputs the rotation speed of the output shaft of the drive source, and controls the transmission section to thereby output the rotation speed of the output shaft of the drive source to the output of the transmission section. A drive transmission control device including a transmission control unit that sets a transmission ratio that is a value divided by the number of rotations of the shaft to a magnitude corresponding to a shift operation state of the shift operation device;
When the gear ratio corresponding to the changed driving state is smaller than a predetermined setting ratio, the braking force reduction control unit, after the control of the transmission unit in the drive transmission control device is finished, the braking force A braking force reduction start unit that starts the reduction of the braking force before the control of the transmission unit in the drive transmission control device is completed when the speed ratio is larger than the set ratio. The vehicle control device according to item (9) or (10).
(12) While the drive source is stopped by the drive source control device, the braking force control device is configured to change the braking force according to an environment in which the vehicle is placed, such as a road surface gradient and a load load. The vehicle control device according to any one of items (3) to (11), including a driving force stop-time braking force control unit that controls the vehicle to a size suitable for keeping the vehicle stopped.
(13) When the drive source control device has a moving force of the vehicle based on an environment in which the vehicle is placed, such as a road surface gradient and a load load, smaller than a braking force controlled by the braking force control device. The vehicle control device according to any one of items (3) to (12), further including a drive source stop unit that can stop and maintain the drive source.
In the vehicle control device described in this section, the drive source is stopped after confirming that the vehicle is in a state where the stop can be maintained. While the drive source is stopped, the vehicle can be reliably kept stopped.
As described in the item (8), it can be considered that the braking force being larger than the moving force is one requirement for the drive source stop condition to be satisfied, but it can also be considered separately. One example is a case where the braking force control is performed first when the driving source stop condition is satisfied, and the driving source is stopped when the braking force is larger than the moving force.
(14) In the braking force control device, when the drive source is stopped by the drive source control device, a moving force of the vehicle generated based on an environment where the vehicle is placed, such as a road surface gradient and a load load, is generated. The vehicle control device according to any one of (3) to (13), further including a driving force stop time braking force increase controller that increases the braking force when the braking force is greater.
When the moving force is larger than the braking force, if the braking force is increased, the vehicle can be reliably kept in the stopped state after the drive source is stopped. When used in conjunction with the drive source control device of (13), if the moving force is greater than the braking force, the braking force control device described in this section increases the braking force and detects that. After that, the drive source is stopped by the drive source control device described in the item (13).
(15) A drive source control device that automatically stops and automatically restarts the drive source when a predetermined drive source stop condition is satisfied while the vehicle is stopped;
A vehicle control device including a braking force control device for controlling a braking force applied to the vehicle,
When the driving source is restarted by the driving source control device, the braking force control device is configured to shift the braking force when the driver performs an operation for instructing start of the vehicle. A vehicle control apparatus comprising a shift operation state corresponding braking force decrease control unit that decreases a pattern according to a type of drive state after the apparatus is changed.
The technical feature described in any one of the items (1) to (14) can be applied to the vehicle control device described in this item.
(16) The vehicle control device according to (15), wherein the shift operation state corresponding braking force decrease control unit decreases the braking force with a gradient according to the type of the drive position.
(17) The vehicle control device shifts and outputs the rotation speed of the output shaft of the drive source, and controls the transmission section to thereby output the rotation speed of the output shaft of the drive source to the output of the transmission section. A drive transmission control device including a transmission control unit that sets a transmission ratio that is a value divided by the number of rotations of the shaft to a magnitude corresponding to a shift operation state of the shift operation device;
When the gear ratio corresponding to the changed driving state is smaller than a predetermined setting ratio, the shift operation state corresponding braking force reduction control unit after the control of the transmission unit in the drive transmission control device is completed When the reduction of the braking force is started and the gear ratio is larger than the set ratio, the braking force reduction starts to reduce the braking force before the control of the transmission unit in the drive transmission control device is finished. The vehicle control device according to item (15) or (16), including a start portion.
(18) The braking force control device comprises:
A braking force detection device for detecting the braking force;
When the braking force is reduced by the shift operation state corresponding braking force reduction control unit by the braking force detection device, and the braking force after the elapse of a predetermined set time is equal to or greater than the predetermined set braking force. The vehicle control device according to any one of (15) to (17), further including an abnormality detection unit that determines that the braking force control device is abnormal.
If the braking force reduction control is performed but the braking force does not decrease accordingly, it can be determined that the braking force control device is abnormal.
(19) A drive source control device that automatically stops and automatically restarts the drive source when a predetermined drive source stop condition is satisfied while the vehicle is stopped;
A vehicle control device including a braking force control device for controlling a braking force applied to the vehicle,
When the drive source is stopped by the drive source control device, the braking force control device is configured to change the braking force according to the environment in which the vehicle is placed, such as road surface gradient and load load. A vehicle control device comprising: a driving force stopping braking force control unit that controls the driving force to a size suitable for maintaining the stopped state.
The technical feature described in any one of the items (1) to (18) can be applied to the vehicle control device described in this item.

Hereinafter, a vehicle control device according to an embodiment of the present invention will be described in detail with reference to the drawings.
A vehicle equipped with this vehicle control device is an automatic vehicle, which is a vehicle driven by an engine. A drive system including an engine is shown in FIG. 1, and a brake system is shown in FIG.
In the drive system shown in FIG. 1, 10 is an engine as a drive source, and 12 is a transmission. A motor generator 14 has a function as a starter motor. The engine 10 is connected to a crankshaft (not shown) of the engine 10 via a speed reduction mechanism including a clutch, a chain, and the like, and the engine 10 is started by driving the motor generator 14. The motor generator 14 is controlled by the motor controller 18 via the inverter 16, and a command is supplied to the motor controller 18 from the engine control device 20. The engine 10 is provided with an injector 22 through which fuel stored in a fuel tank is supplied. Although not shown, the injector 22 includes a needle valve and a solenoid. When the solenoid is excited, the needle valve is opened and fuel is injected. If the solenoid is de-energized, it is closed, fuel is not supplied, and the engine 10 is stopped.

  The transmission 12 includes a torque converter 30 and a planetary gear unit 32. The torque converter 30 includes a pump impeller 36 that can rotate integrally with the output shaft 34 of the engine 10, and a turbine impeller that can rotate integrally with an input shaft (output shaft of the torque converter 30) 38 to the planetary gear unit 32. 40 and a stator impeller 42 provided on the main body via a clutch 41. The driving torque of the output shaft 34 of the engine 10 is transmitted to the input shaft 38 of the planetary gear unit 32 by the fluid flowing between them.

The planetary gear unit 32 includes a plurality of planetary gears, clutches, brakes, and the like, and these clutches, brakes, and the like are switched from the non-engaged state to the engaged state when hydraulic fluid is supplied. The hydraulic fluid is selectively supplied to these clutches and brakes by the operation of the hydraulic actuator 46.
The hydraulic actuator 46 includes a hydraulic circuit including a manual valve that is mechanically switched in response to switching of a shift lever 48 serving as a shift operation device, and a plurality of solenoid valves (solenoids). Under the control of the solenoid, the hydraulic fluid is supplied to a clutch and a brake that are determined in advance according to the set gear ratio. The gear ratio is determined based on the shift position based on the operation of the shift lever 48, the vehicle speed, and the like.
The hydraulic actuator 46 described above is controlled by the transmission control device 50.

Next, the braking system will be described.
FIG. 2 shows a hydraulic braking device 58 included in the vehicle. 60 is a brake pedal, 62 is a master cylinder, and includes two pressurizing chambers. Front wheel cylinders 66 and 68 are connected to one pressurizing chamber via a liquid passage 64, and rear wheel wheel cylinders 72 and 74 are connected to the other pressurizing chamber via a liquid passage 70. The The liquid passages 64 and 70 are branched in the middle, and a wheel cylinder is provided at each tip.

  A fluid pressure control valve 80 is provided at a portion upstream of the branch position of the fluid passage 64 in which the front wheel cylinders 66 and 68 are provided at the front ends. As will be described later, the hydraulic pressure control valve 80 is capable of controlling the wheel cylinder hydraulic pressure to a magnitude corresponding to the amount of current supplied to the solenoid. A check valve 81 is provided in the middle of the bypass passage that bypasses the hydraulic control valve 80. The check valve 81 allows a flow from the master cylinder side to the wheel cylinder side and prevents a reverse flow. When the hydraulic pressure in the master cylinder 62 increases when the hydraulic pressure control valve 80 is in the closed state, the check valve 81 can quickly supply the hydraulic fluid in the master cylinder 62 to the wheel cylinders 66 and 68. It becomes possible. An electromagnetic on-off valve 82 is provided between the hydraulic control valve 80 and the wheel cylinders 66 and 68, and a check valve 83 is provided in the middle of a bypass passage that bypasses the electromagnetic on-off valve 82. The check valve 83 allows the flow of hydraulic fluid from the wheel cylinder side to the master cylinder side, and prevents reverse flow. Even if the electromagnetic on-off valve 82 is in the closed state, the check valve 83 can quickly return the hydraulic fluid in the wheel cylinders 66 and 68 to the master cylinder 62 when the operation of the brake pedal 60 is released. . Between the wheel cylinders 66 and 68 and the reservoir 84, electromagnetic on-off valves 86 are respectively provided. These electromagnetic on-off valves 82 and 86 are opened and closed by solenoid ON / OFF control, respectively. In anti-lock control and traction control, the wheel cylinder hydraulic pressures are set in the braking slip state and the driving slip state of the wheel. It is controlled so as to be kept in an appropriate state. Further, during vehicle stability control, control is performed so that the traveling state of the vehicle is maintained in an appropriate state.

A pump passage 90 extends from the reservoir 84 and is connected to the upstream side of the electromagnetic on-off valve 82. A pump 92, a plurality of check valves 93, 94, 95, a damper 96, and the like are provided in the middle of the pump passage 90, and hydraulic fluid in the reservoir 84 can be pressurized and supplied to the wheel cylinders 66, 68. Has been. The pump 92 is operated by driving a pump motor 98.
A hydraulic fluid supply passage 102 extending from the master reservoir 100 is connected between the check valves 94 and 95 on the downstream side of the pump 92 in the pump passage 90. An electromagnetic on-off valve 104 is provided in the middle of the hydraulic fluid supply passage 102, and the hydraulic fluid in the master reservoir 100 is supplied to the pump passage 90 by opening the electromagnetic on-off valve 104. A hydraulic fluid supply passage 106 extending from the master cylinder 62 is connected to the hydraulic fluid supply passage 102 downstream of the electromagnetic on-off valve 104. An electromagnetic on-off valve 108 is provided in the middle of the hydraulic fluid supply passage 106, and the hydraulic fluid in the master cylinder 62 is supplied to the pump passage 90 by opening the electromagnetic on-off valve 108. The pump passage 90, the pump 92, the pump motor 98, etc. constitute a power pressurizing device 110.

  The power pressurization device 110 is operated when the wheel cylinder hydraulic pressure is controlled to be different from the master cylinder hydraulic pressure, such as during anti-lock control, traction control, and vehicle stability control. When the power pressurization device 110 is operated, the wheel cylinders 66 and 68 are shut off from the master cylinder 62 by the hydraulic pressure control valve 80. When the amount of hydraulic fluid stored in the reservoir 84 is large, such as during anti-lock control, the hydraulic fluid in the reservoir 84 is pressurized and supplied to the wheel cylinders 66 and 68. When almost no hydraulic fluid is stored, such as during traction control or vehicle stability control, the electromagnetic on-off valve 104 is switched to the open state, and hydraulic fluid is supplied from the master reservoir 100 to the pump passage 90. The hydraulic fluid supplied from the master reservoir 100 is sucked into the pump 92 without being returned to the reservoir 84 by the check valve 95.

  When the wheel cylinder hydraulic pressure is set higher than the master cylinder hydraulic pressure, the wheel cylinders 66 and 68 are disconnected from the master cylinder 62 by the hydraulic pressure control valve 80 in the same manner as described above. The electromagnetic on-off valve 104 is closed and the electromagnetic on-off valve 108 is opened. High pressure hydraulic fluid is supplied to the pump passage 90 from the master cylinder 62, pressurized by the pump 92, and supplied to the wheel cylinders 66 and 68. The check valve 95 prevents the high-pressure hydraulic fluid supplied from the master cylinder 62 to the pump passage 90 from being returned to the reservoir 84. If the high-pressure hydraulic fluid of the master cylinder 62 is used, the amount of energy consumed in the pump motor 98 can be reduced correspondingly, and the energy can be used effectively. Thus, the wheel cylinder hydraulic pressure can be made higher than the master cylinder hydraulic pressure by the hydraulic pressure control valve 80 and the power pressurizing device 110. In addition, the electromagnetic on-off valve 108 and the liquid passage 106 can use the hydraulic fluid of the master cylinder 62 to increase the wheel cylinder hydraulic pressure while reducing energy consumption.

  A check valve 112 that allows the flow of hydraulic fluid from the master reservoir 100 to the pump passage 90 but prevents reverse flow is provided in the middle of the hydraulic fluid supply passage 102 on the front wheel side. The check valve 112 prevents the hydraulic fluid of the master cylinder 62 from flowing into the master reservoir 100 when both the electromagnetic on-off valves 104 and 108 are simultaneously opened. The reason why the check valve 112 is provided on the front wheel side and not on the rear wheel side is that the brake on the front wheel side is more important than the brake on the rear wheel side. Of course, it may also be provided on the rear wheel side, or may be provided on the common part of the front wheel side and the rear wheel side of the hydraulic fluid supply passage.

  The hydraulic control valve 80 is a normally open linear valve, and as shown in FIG. 3, a valve that controls the flow of hydraulic fluid between a housing (not shown) and the wheel cylinders 66 and 68 and the master cylinder 62. 130 and a seating valve 133 including a valve seat 1322 to be seated, and a solenoid 134 for generating a magnetic force for controlling the relative movement of the valve element 130 and the valve seat 132.

In the hydraulic pressure / hydraulic pressure control valve 80, when the solenoid 134 is not excited (OFF state), the valve element 130 is separated from the valve seat 132 by the elastic force of the spring 136, whereby the wheel cylinders 66, Bidirectional hydraulic fluid flow between 68 and the master cylinder 62 is allowed. The hydraulic fluid of the master cylinder 62 is supplied to the wheel cylinders 66 and 68, and the normal brake is operated.
On the other hand, when the solenoid 134 is excited (ON state), the armature 138 is attracted by the magnetic force of the solenoid 134 and the valve element 130 is seated on the valve seat 132. At this time, the valve element 130 has a solenoid attraction force F ₁ based on the magnetic force of the solenoid 134, a force F ₂ based on the differential pressure between the wheel cylinder hydraulic pressure and the master cylinder hydraulic pressure, and an elastic force F _{3 of the} spring 136. The sum of these acts in opposite directions.

The solenoid 134 is excited (ON state) and has a large suction force with respect to the differential pressure between the wheel cylinder hydraulic pressure and the master cylinder hydraulic pressure.
F ₂ ≦ F ₁ −F ₃
In the region where the relationship expressed by the following formula is established, the valve element 130 is seated on the valve seat 132 and the hydraulic fluid from the wheel cylinders 66 and 68 is prevented from flowing out. The suction force is small against the above differential pressure,
F ₂ > F ₁ −F ₃
In a region where the relationship expressed by the following formula is established, the valve element 130 is separated from the valve seat 132, and the hydraulic fluid in the wheel cylinders 66 and 68 is returned to the master cylinder 62 and depressurized.

Thus, since the relative position of the valve element 130 with respect to the valve seat 132 is determined by the above-described three forces F ₁ , F ₂ , and F ₃ , the differential pressure can be controlled by controlling the magnitude of the suction force. The hydraulic pressure of the wheel cylinders 66 and 68 can be controlled. Further, the distance between the valve element 130 and the valve seat 132 can be controlled, and the pressure reduction gradient of the wheel cylinder hydraulic pressure can also be controlled. The solenoid 134 is controlled based on a command from the brake control device 140.
Since the hydraulic system on the rear wheel side is the same as that on the front wheel side, the same reference numerals are given and description thereof is omitted.

  Each of the engine control device 20, the transmission control device 50, and the brake control device 140 is mainly composed of a computer. The input unit 148 of the engine control device 20 includes an accelerator switch 150 that is turned on when an accelerator pedal (not shown) is depressed, a shift position sensor 152 that detects the position of the shift lever 48, and a vehicle speed sensor 154 that detects the vehicle speed. The turbine rotation speed sensor 156 that detects the rotation speed of the input shaft 38 that can rotate integrally with the turbine impeller 40 of the torque converter 30, and the relative relationship between the frame as the vehicle body side member and the suspension arm as the wheel side member A vehicle height sensor 158 that detects displacement, an acceleration sensor 160 that detects longitudinal acceleration of the vehicle, an engine stop permission switch 162, and the like are connected.

  Based on the change in the rotational speed of the input shaft 38 detected by the turbine rotational speed sensor 156, in the planetary gear unit 32, whether or not the predetermined clutch has been switched from the non-engaged state to the engaged state (to the clutch). Whether or not the supply of the hydraulic fluid has been completed is known. The vehicle height sensor 158 is provided corresponding to each of the four wheels, and based on the output signals of the four vehicle height sensors 158, the vehicle body inclination weight θ with respect to the road surface or the load weight of the vehicle in a horizontal state. Can be obtained. Further, the acceleration sensor 160 detects an inertial force applied to the pendulum, and the inclination φ with respect to the horizon of the vehicle can be acquired based on an output signal of the acceleration sensor 160 when the vehicle is in a stopped state. Further, the engine stop permission switch 162 is provided in the passenger compartment, and is switched between the ON state and the OFF state by the operation of the driver. The drive source stop control is performed when the engine stop permission switch 162 is in the ON state.

  A motor controller 18, an alarm device 167, and the like are connected to the output unit 164 of the engine control device 20, and a solenoid of the injector 22 is connected via a drive circuit. The ROM 168 stores various programs such as programs related to the drive source stop control represented by the flowcharts of FIGS. These programs are executed by the CPU 172 while using the RAM 174.

  The transmission control device 50 controls a plurality of solenoids included in the hydraulic actuator 46 of the transmission 12 based on information supplied from the engine control device 20. As described above, the hydraulic fluid is controlled to be supplied to a clutch, a brake, etc. that can realize the set gear ratio.

  The input unit 180 of the brake control device 140 includes a brake switch 184, a master pressure sensor 186 for detecting the master pressure, a wheel cylinder hydraulic pressure sensor 188 for detecting the wheel cylinder hydraulic pressure, and a wheel speed for detecting the wheel speed of each wheel. Sensor 189, not shown, is connected to a sensor necessary for vehicle stability control such as a yaw rate sensor and a lateral G sensor. The output unit 190 is connected to a solenoid 134 of each electromagnetic valve through a drive circuit. In the ROM 192, although a flowchart is omitted, a plurality of programs such as a hydraulic control valve control program, an antilock control program, a traction control program, a vehicle stability control program, and a plurality of control patterns for controlling the solenoid are provided. A plurality of tables such as a table to represent are stored. These programs are executed by the CPU 194 using the RAM 196.

  Information is communicated among the engine control device 20, the transmission control device 50, and the brake control device 140. Information regarding the shift position is output from the engine control device 20 to the transmission control device 50. From the engine control device 20 to the brake control device 140, information indicating a holding command, information indicating a pressure reduction command (braking force release command), information indicating a pressure increase command (braking force increase command) (hydraulic pressure control command / braking force) Control command) and the like, and information indicating the state of the brake switch 184, information indicating the wheel cylinder pressure, and the like are supplied from the brake control device 140 to the engine control device 20. The communication of these information may be output according to the information requesting the information, or may be recorded in the memory of the output unit so as to be always readable.

The engine control device 20 determines whether or not the engine stop condition is satisfied and whether or not the engine restart condition is satisfied based on information indicating the state of the brake switch 184 supplied from the brake control device 140. The Further, based on information representing wheel cylinder hydraulic pressure supplied from the brake control device 140 or the like, it is determined whether or not the braking force is an appropriate magnitude.
In the brake control device 140, the supply current and the like to the solenoid 134 of the hydraulic control valve 80 is supplied from the engine control device 20 (i) information representing the hold command, and (ii) information representing the pressure reduction command. (Iii) Control is performed based on information indicating a pressure increase command. When the information indicating the holding command (i) is supplied, a current capable of holding the wheel cylinder hydraulic pressure at that time is supplied. The decompression command (ii) includes a rapid decompression command and a slow decompression command, and the ROM 192 stores a decrease pattern of the supply current corresponding to each, and the supply current is decreased according to the pattern. When the information indicating the pressure increase command (iii) is supplied, the information indicating the target hydraulic pressure (necessary hydraulic pressure) of the wheel cylinder is also supplied. The solenoid 134 of the hydraulic pressure control valve 80 is supplied with a current having a magnitude that can achieve the required hydraulic pressure, the electromagnetic on-off valve 104 is closed, and the electromagnetic on-off valve 108 is opened. Further, the pump motor 98 is driven. The hydraulic fluid in the master cylinder 62 is pressurized by the pump 92 and supplied to the wheel cylinder, and the hydraulic pressure in the wheel cylinder is made larger than the hydraulic pressure in the master cylinder. The wheel cylinder hydraulic pressure is controlled to a magnitude corresponding to the supply current of the hydraulic pressure control valve 80.

The case where drive source stop control is performed in the vehicle control device configured as described above will be described. In the drive source stop control, the operation of the engine 10 is stopped when a predetermined engine stop condition is satisfied, and then the engine 10 is restarted when a predetermined restart condition is satisfied. It is.
In this embodiment, when the engine stop permission switch 162 is in the ON state, (i) the vehicle speed is substantially zero, (ii) the brake pedal 60 is being operated, and (iii) the accelerator switch 150 is It is assumed that the engine stop condition is satisfied when the four states of being in the OFF state and (iv) the shift position being the non-driving position (parking “P”) are satisfied and the state continues for the set time or longer. . The wheel cylinder hydraulic pressure is controlled, and control of the injector 22 prevents fuel injection into the combustion chamber and stops the engine 10.

  When the engine stop conditions (i) to (iv) described above are satisfied, the wheel cylinder hydraulic pressure is applied to the vehicle according to the environment in which the vehicle is placed. The engine 10 is controlled to be larger than the moving force, and then the engine 10 is stopped. This is to ensure that the vehicle is stopped when the engine 10 is stopped. The wheel cylinder hydraulic pressure is maintained at the magnitude while the engine 10 is stopped.

The wheel cylinder hydraulic pressure when the engine is stopped is controlled according to the execution of the engine stop time control program represented by the flowchart of FIG. This program is executed when the engine stop condition described above is satisfied. In step 1 (hereinafter abbreviated as S1. The same applies to other steps), the output signal of the vehicle height sensor 158 provided corresponding to each of the four wheels is read, and in S2, the four vehicle height sensors are read. The inclination angle θ with respect to the road surface of the vehicle body is obtained based on the output signal (see FIG. 7A). In S3, the output signal of the acceleration sensor 160 is read, and in S4, the inclination angle φ with respect to the horizon of the vehicle is obtained. In S5, the gradient Θ with respect to the horizontal line of the road surface is obtained based on the inclination angle θ with respect to the road surface of the vehicle and the inclination angle φ with respect to the horizontal line. In S6, the load weight W is determined based on the gradient Θ and the output signal of the vehicle height sensor. Is required. In S7, the wheel cylinder hydraulic pressure P ^* required to keep the vehicle stopped is determined based on the gradient Θ and the loaded weight W.
As shown in FIG. 7B, when the inclination direction with respect to the road surface of the vehicle body is the same as the inclination direction with respect to the horizontal line, the gradient θ with respect to the horizontal line of the road surface is represented by φ−θ. On the other hand, as shown in (c), when the inclination direction with respect to the road surface of the vehicle body is different from the inclination direction with respect to the horizontal line, the gradient Θ is represented by φ + θ. Further, since the output signal of the vehicle height sensor 158 is influenced by the gradient Θ with respect to the horizontal line of the road surface, the load weight W is obtained after the gradient Θ is obtained.

Further, in S8, information representing the actual wheel cylinder hydraulic pressure P supplied from the brake control device 140 is read, and in S9, it is determined whether or not the actual hydraulic pressure P is equal to or higher than the required hydraulic pressure P ^* . If it is equal to or higher than the required hydraulic pressure P ^* , a holding command for holding the braking force is output to the brake control device 140 in S10. This is because the vehicle can be kept in a stopped state by a braking force corresponding to the amount of brake operation by the driver. Thereafter, in S11, the engine 10 is stopped. On the other hand, if the actual hydraulic pressure P is smaller, a pressure increase command is output in S12 to increase the braking force. The brake control device 140 controls the amount of current supplied to the solenoid 134 of the hydraulic pressure control valve 80, and controls to increase the wheel cylinder hydraulic pressure by controlling the pump motor 98 and the like. Thereafter, the process returns to S8, where it is determined whether or not the actual hydraulic pressure P is greater than or equal to the required hydraulic pressure P ^* . If the actual hydraulic pressure P is smaller, S9 and S12 are executed. If S8, 9, and 12 are repeatedly executed to reach the required hydraulic pressure P ^* or more, the determination in S9 is YES, a holding command is output in S10 and 11, and the engine 10 is stopped.

Thus, when the engine stop condition is satisfied and the braking force is smaller than the moving force, the braking force is set to be equal to or greater than the moving force, and then the engine 10 is stopped. As a result, when the engine 10 is stopped, the vehicle can be reliably kept in a stopped state.
Further, the stopping braking force is set to an appropriate magnitude based on the road surface gradient, the loaded weight, etc., and is not always the maximum magnitude. Therefore, it is possible to start quickly as compared with the case where the maximum size is always set. When the vehicle is started, the wheel cylinder hydraulic pressure is reduced. In this case, the time required for the pressure reduction can be shortened and the startability can be improved. Further, the vehicle height control is not performed in this vehicle. This is because when the vehicle height control is performed, it is impossible to acquire the vehicle inclination angle and the loaded load based on the output signal of the vehicle height sensor 158.

In the above-described embodiment, the necessary hydraulic pressure is determined based on both the road surface gradient and the loaded weight, but may be determined based on either one. It is also possible to determine the necessary wheel cylinder hydraulic pressure based on the vehicle inclination state acquired based on the output signal of either the acceleration sensor 160 or the vehicle height sensor 158.
In the above embodiment, it is determined whether or not the wheel cylinder hydraulic pressure is equal to or higher than the required hydraulic pressure. However, it is determined whether or not the master cylinder hydraulic pressure is equal to or higher than the required hydraulic pressure. Also good. This is because it can be considered that the wheel cylinder hydraulic pressure is substantially the same as the master cylinder hydraulic pressure while the hydraulic control valve 80 is in communication. In this case, feedback (returning to the execution of S8 after the execution of S12 and repeatedly executing S8, 9, 12 until the actual hydraulic pressure becomes equal to or higher than the required hydraulic pressure) is not performed, and the determination of S9 When NO is NO, only the information indicating the required hydraulic pressure is output. In the hydraulic braking device 58, a necessary current is supplied to the hydraulic control valve 80, and the power pressurizing device 110 is operated. It is not determined whether or not the wheel cylinder hydraulic pressure is higher than the required hydraulic pressure. According to this embodiment, the wheel cylinder hydraulic pressure sensor (pressure sensor) 188 is not necessary. In step S8, the master cylinder hydraulic pressure is read.
Further, instead of the acceleration sensor 160, a gradient sensor may be used. Further, it can be considered that the braking force being larger than the moving force is one requirement for satisfying the engine stop condition.

Next, control during engine restart will be described. The engine 10 is started when the engine restart condition is satisfied. The crankshaft is rotated by the operation of the starter motor 14, and fuel is supplied to the combustion chamber by the control of the injector 22.
In the present embodiment, when the shift position of the shift lever 48 is switched to a drive position, for example, any one of drive “D”, low “L”, reverse “R”, and second “2nd”, the engine It is assumed that the restart condition is satisfied, and the engine 10 is restarted. Further, when the operation of the brake pedal 60 is released, it is assumed that the start instruction operation is performed, and the wheel cylinder hydraulic pressure is reduced.

  The depressurization gradient when depressurizing the wheel cylinder hydraulic pressure is determined according to the type of shift position. When the shift position after the shift is any one of drive “D”, low “L”, and reverse “R”, the pressure is suddenly reduced, and when it is second “2nd”, the pressure is slowly reduced. In the case of the former drive “D”, low “L”, or reverse “R”, the wheel cylinder hydraulic pressure is reduced without confirming that the clutch in the transmission 14 is engaged. However, in the case of the latter second “2nd”, it is started when the clutch is engaged (when the supply of the hydraulic fluid is finished). In the case of the second “2nd”, the depressurization start timing is delayed, and the depressurization gradient is reduced, so that the depressurization is performed slowly. Whether the clutch is engaged or not is detected based on a change in the rotational speed of the output shaft 38 of the torque converter 30. When engaged, the load on the output shaft 38 increases and the rotational speed decreases.

  If the operation of the brake pedal 60 is not released within the set time despite the engine 10 being started, it is determined again whether or not the engine stop condition is satisfied. In the present embodiment, when the stop condition is satisfied (when the shift position is returned to the non-drive position), the engine 10 is stopped again. However, when the stop condition is not satisfied, the operating state of the engine 10 is stopped. Thus, the vehicle is brought into a normal vehicle stop state in which the drive source stop control is not performed. In this case, a drive stop control standby state for monitoring whether or not the engine stop condition is satisfied is set.

  In the flowchart of FIG. 5, in S51, information indicating the state of the brake switch 184 supplied from the brake control device 140 is read, and in S52, it is determined whether or not the state of the brake switch 184 is ON. If the operation state of the brake pedal 60 is maintained and is still ON, the determination is YES, and S53 and subsequent steps are executed. In S53, the shift position is read based on the output signal of the shift position sensor 152, and in S54, it is determined whether or not the shift lever 48 has been shifted. It is determined whether or not the shift position has been changed from parking “P” to another position. If not shifted, the process returns to step S51. If shifted, S55 and subsequent steps are executed.

  When the shift position after the shift is neutral “N”, the process returns to S51 as in the case where the shift of the shift lever 48 is not performed. When the shift position is any other position, the process proceeds to S56 to 59. The engine 10 is restarted, and information indicating the shift position is output to the transmission control device 50. The transmission control device 50 controls the solenoid of the hydraulic actuator 46 according to the shift position. In the case of the drive “D” and the low “L”, a hydraulic circuit that realizes the low “L” (1st) is formed.

Thereafter, whether or not the operation of the brake pedal 60 is released within the set time is determined by executing S60 and 61. When the brake operation is released within the set time, the braking force is released at a gradient corresponding to the shift position after S62. In S62, it is detected which shift position after the shift is. If the drive is “D”, low “L”, or reverse “R”, a decompression command (rapid decompression) is output to the brake control device 140 in S63. If the shift position is the second “2nd”, it is detected in S64 and 65 that the clutch corresponding to the second “2nd” has changed from the non-engaged state to the engaged state, Decompressed) is output.
When the shift lever 48 is shifted to the second “2nd” by the driver, a smaller driving force is required than when the shift lever 48 is shifted to the drive “D”, low “L”, and reverse “R”. This is because, for example, when the road surface friction coefficient μ is low, sudden start is avoided and tire idling is avoided. Therefore, if the wheel cylinder hydraulic pressure is reduced with a gentle gradient, sudden start can be avoided, and the same effect as when the driver slowly loosens the brake pedal 60 can be obtained. Moreover, since the depressurization start timing is also delayed, the depressurization can be performed slowly.
In any case, after the engine 10 is restarted, the engine control device 20 is set to the drive source stop control standby mode in S66. Since a series of drive source stop control (stopping and restarting the engine 10 to start the vehicle) has been finished, it is again monitored whether or not the engine stop condition is satisfied.

On the other hand, if the operation of the brake pedal 60 is not released within the set time, the determination in S61 is NO, and it is determined in S67 whether or not the engine stop condition is satisfied. For example, it is determined whether or not the shift position or the like has been returned to the parking “P” again. If the parking "P" is not returned and the stop condition is not satisfied, the determination is NO and the drive source stop control standby mode is set in S66. In this case, the engine 10 is being operated while the vehicle is stopped, that is, the vehicle is in a stopped state where drive source stop control is not performed. If the engine stop condition is satisfied, the engine 10 is stopped. Will be.
If the engine stop condition is satisfied, the engine 10 is stopped again in S68, and the process returns to S51. It is detected whether the engine restart condition is satisfied.

On the other hand, when the release of the operation of the brake pedal 60 is performed before the operation of the shift lever 48, the determination in S52 is NO, and the steps after S70 are executed.
In S70 in the flowchart of FIG. 6, the shifted shift position is detected. If the shift position is any one of the drive “D”, low “L”, and reverse “R”, the engine 10 is restarted in S71 to 73, and information indicating the shift position is transmitted to the transmission control device 50. The pressure reduction command (rapid pressure reduction) is output to the brake control device 140. The supply of hydraulic fluid to a clutch or the like that can realize the shift position described above is started and the wheel cylinder hydraulic pressure is reduced with a steep slope.

When the shift position after the shift is the second “2nd”, the engine 10 is restarted in S 74 to 77, and information indicating the shift position is output to the transmission control device 50. Then, after detecting that the clutch corresponding to the second “2nd” is switched from the non-engaged state to the engaged state, a pressure reduction command (slow pressure reduction) is output to the brake control device 140. The wheel cylinder hydraulic pressure is reduced with a gentle gradient.
When the shift position is neutral “N”, the process returns to S51, and S51, 52, and 70 are repeatedly executed until the shift position is shifted to the drive position. Since the wheel cylinder hydraulic pressure is maintained unless shifted to the drive position, the vehicle is not moved even when the operation of the brake pedal 60 is released.

  Thus, according to the vehicle control device of the present embodiment, even when the brake operation state is maintained, the shift lever 48 is shifted to the drive position, that is, the start preparation operation is performed. In this case, the engine 10 is restarted, so that when the brake operation is released and the accelerator operation is performed, the vehicle can be started quickly. Further, when switching to the second “2nd”, since the wheel cylinder hydraulic pressure is slowly reduced, sudden start can be suppressed and excessive driving slip can be avoided. When the gear ratio is small, the pressure is slowly reduced. The gear ratio can be the value obtained by dividing the number of revolutions of the engine output shaft by the number of revolutions of the output shaft of the transmission, but the value obtained by dividing the gear ratio of the output side rotational shaft by the gear ratio of the input side rotational shaft. It can also be expressed as Further, when the brake operation is not released within the set time after the engine is started, the engine 10 is stopped again, so that the wasteful consumption of energy can be reduced.

  In the above embodiment, when switching to the second “2nd”, the pressure reduction of the wheel cylinder hydraulic pressure is started after the clutch is engaged, but the clutch is not engaged. The pressure reduction may be started while in the combined state. Since the pressure is reduced with a gentle gradient, sudden start can be avoided and idling of the tire can be suppressed. Conversely, even when the shift is made to low “L”, drive “D”, or reverse “R”, sudden pressure reduction can be started after the clutch is engaged. In this case, a step of determining whether or not the clutch is engaged may be provided before at least one of steps S63 and S73. Furthermore, pressure reduction may be started while hydraulic fluid is being supplied to the clutch (in the middle of engagement).

  In the above embodiment, the start instruction operation is performed when the operation of the brake pedal 60 is released, and the wheel cylinder hydraulic pressure is reduced. However, the start instruction operation is performed when the accelerator operation is performed. It can also be made to be decompressed as operation was performed. In this case, even when the brake operation is released when the vehicle is stopped on a slope, the vehicle can be prevented from being lowered, and the slope can be started satisfactorily. Further, in S60, when it is detected that the operation of the brake pedal 60 is released, it is not essential to reduce the wheel cylinder hydraulic pressure with a gradient corresponding to the shift position. The pressure can be reduced by either method. Also in this case, since the engine 10 is started prior to the reduction of the wheel cylinder hydraulic pressure, the engine 10 can be started quickly according to the accelerator operation. If the brake is not released within the set time after the engine 10 is started, the engine 10 is stopped after it is determined in S67, 68 that the engine stop condition is satisfied. If the brake release operation is not performed within the set time, the engine 10 may be stopped regardless of whether the engine stop condition is satisfied. In S68, the engine 10 is not stopped, but the driving force can be reduced to the set driving force or can be in a no-load state. Further, the driving force can be decreased stepwise with the elapsed time, or can be gradually decreased gradually.

  As described above, in this embodiment, the motor generator 14, the inverter 16, the motor controller 18, the injector 22, the engine control device 20, the shift position sensor 152, and the like constitute a drive source control device. Among them, the motor restart generator 14, the inverter 16, the motor controller 18, the shift position sensor 152, the part that stores S 55, 56, 58 of the drive source stop control program of the engine control device 20, the part to be executed, etc. Is constructed, and the state of the brake switch 184, the state of the brake switch 184 of the brake control device 140 is detected and output to the engine control device 20, and the portion for executing S60, 61, 67, 68 of the engine control device 20 is stored The driving force reducing portion is constituted by the portion or the like. In the present embodiment, the release of the operation of the brake pedal 60 corresponds to the operation of instructing the start of the vehicle by the driver, and the driving force is reduced by stopping the engine 10. Further, the vehicle height sensor 158, the acceleration sensor 160, the part that executes S1 to 11 of the engine control device 20, the part that stores the vehicle, etc. constitute a drive source stop part when the vehicle can be maintained.

On the other hand, a portion for controlling the hydraulic pressure control valve 80, the hydraulic pressure control valve 80 of the brake control device 140, and a portion for calculating the braking force of the engine control device 20 and outputting a command corresponding to the calculation to the brake control device 140 Thus, a braking force control device is configured. Of the braking force control device, S1-12 of the engine control device 20 is stored and driven by a portion to be executed and a portion of the brake control device 140 that controls the operation state of the hydraulic pressure control valve 80 and the motor 98 accordingly. A braking force control unit when the power is stopped is configured. The wheel cylinder hydraulic pressure held in S10 is held even when the engine 10 is stopped. Further, the braking force control unit when the driving source is stopped is also a braking force increase control unit when the driving source is stopped.
Further, the braking force reduction control is performed by the part that stores S62 to 65, S70, 73, 76, and 77 of the engine control device 20, the part that executes it, the part that controls the hydraulic control valve 80 according to the brake control device 140, and the like. The part is composed. The braking force reduction control unit is also a shift position corresponding braking force reduction control unit. In addition, a braking force reduction start unit is configured by the portions that execute S63, 64, 65, 73, 76, and 77 in the braking force reduction control unit.

  In the above embodiment, the program represented by the flowcharts of FIGS. 4 to 6 is executed by the engine control device 20, but the program represented by the flowchart of FIG. 4 is executed by the brake control device 140. May be. In addition, it is not essential to have three computers of the engine control device 20, the transmission control device 50, and the brake control device 140, and they may be executed by one computer. Furthermore, the engine stop condition is not limited to the above-described condition, and may be two or more of the four conditions. Also, other conditions can be added or replaced with other conditions.

  Furthermore, the engine stop time control program represented by the flowchart of FIG. 4 and the engine restart time control program represented by the flowchart of FIG. 5 can be executed independently of each other. That is, when the engine stop time control program is executed, it is not essential that the engine restart condition is that the shift lever 48 is shifted to the drive position, and the engine restart time control program is executed. Therefore, it is not necessary to control the braking force to be larger than the moving force when the engine 10 is stopped. Further, in the engine restart control program represented by the flowchart of FIG. 5, S52, 70 to 77, 66 can be executed separately from other steps. The restart of the engine 10 when the shift lever 48 is switched to the drive position and the control of the pressure reduction gradient of the wheel cylinder hydraulic pressure at the start can be performed independently. In this case, when the operation of the brake pedal 60 is released, the start of the engine 10 and the reduction of the wheel cylinder hydraulic pressure can be performed in parallel.

Furthermore, in the above-described embodiment, the braking force is not controlled when the engine 10 is restarted. However, the braking force can be controlled to a size that can keep the vehicle stopped when the engine 10 is restarted.
As shown in the flowchart of FIG. 8, before the engine 10 is restarted, the warning device 167 is activated when the braking force is smaller than the driving force estimated to be generated at the time of restart. In addition, a pressure increase command is output to the brake control device 140. When the braking force is larger than the driving force, the engine 10 is restarted, and the vehicle can be kept stopped at the time of restart.

When the shift lever 48 is shifted to the drive position while the engine 10 is stopped, the shift position is detected. When the shift position after the shift is drive “D”, low “L”, or reverse “R”, the driving force output when the engine 10 is restarted is estimated in S91 according to the position after the shift. The In S92, the braking force actually applied at the present time is acquired based on the wheel cylinder hydraulic pressure supplied from the brake control device 140, and in S93, the driving force and the braking force are compared. If it is determined as a result of the comparison that the driving force is greater than the braking force, the alarm device 167 is actuated in S94 and 95, and a command (pressure increase command) for increasing the braking force is issued. Thereafter, in S93, the driving force and the braking force are compared, and if the braking force becomes larger, the engine 10 is restarted in S56.
The same control is performed in the case of the second “2nd”. In S91, the driving force corresponding to the second is estimated, and the driving force and the braking force are compared. If the braking force is greater than the driving force, the engine 10 is started in S58, and shift position information representing the second is output to the transmission control device 50 in S59.

According to the present embodiment, it is confirmed that the braking force is greater than the driving force before the engine 10 is restarted. Therefore, when the engine 10 is restarted, the vehicle can be reliably maintained in a stopped state.
In the present embodiment, the driving / braking force comparison device is configured by the portion that stores and executes S93 of the engine control device 140, and the braking force increase control at the time of driving source restart is performed by the portion that stores and executes S95. The part is composed.
It is not essential to provide both steps S94 and S95, and either the alarm device 167 may be activated or a pressure increase command may be output. If the alarm device 167 is activated and the driver thereby increases the amount of brake operation, the braking force can be increased. In S93, when it is determined that the braking force is greater, the engine 10 may be restarted after outputting the holding command. Further, in S92, as in S8, the braking force can be estimated based on the master cylinder hydraulic pressure instead of the wheel cylinder hydraulic pressure.

  Further, after a set time has elapsed since the start of the pressure reduction control, the wheel cylinder hydraulic pressure is detected, and when the detected hydraulic pressure is equal to or higher than the set hydraulic pressure, the hydraulic pressure control valve 80 or the like is abnormal. It is also possible to detect. When it is detected that there is an abnormality, the alarm device 167 can be activated or the driving force of the engine 10 can be reduced. If the driving force is reduced, it is possible to avoid a marked deterioration in fuel consumption. Further, the structure of the hydraulic braking device is not limited to that in the above-described embodiment, but may be of another structure. For example, an electromagnetic on-off valve can be used instead of the hydraulic control valve 80. Furthermore, a wheel cylinder hydraulic pressure sensor 188 for detecting wheel cylinder hydraulic pressure may be provided for each wheel cylinder. Conversely, if there is a master cylinder hydraulic pressure sensor 186, the wheel cylinder hydraulic pressure sensor 188 is not essential. In addition, it is essential that the hydraulic fluid supply passage for supplying the hydraulic fluid to the pump passage 92 includes both the hydraulic fluid supply passage 102 connected to the master reservoir 100 and the hydraulic fluid supply passage 106 connected to the master cylinder 62. Instead, only one of them may be used. Furthermore, it is not essential to be able to execute antilock control, traction control, vehicle stability control, and the like. The electromagnetic on-off valves 82 and 86 are not indispensable.

In the above-described embodiment, the shift operation device includes the shift lever 48, and the shift position is changed by changing the position of the shift lever 48. A plurality of operation members (for example, push buttons) provided corresponding to each of the operation members may be included. In this case, it is changed by switching one of the plurality of operation members from the non-operation state to the operation state. Moreover, it can also be set as the apparatus made to shift up or down one step at a time with operation of an operation member. In this case, the operation member is changed by increasing the number of operations.
Further, in the above embodiment, the vehicle control device is applied to a vehicle driven by an engine, but is applied to a vehicle driven by an engine and an electric drive source or a vehicle driven by an electric drive source instead of an engine. You can also Furthermore, the present invention can be applied not only to a vehicle including a hydraulic pressure control device but also to a vehicle including an electric braking device that presses a friction member against a brake rotating body by an electric motor. In addition to the aspects described in the section [Problems to be Solved by the Invention, Problem Solving Means and Effects], various modifications and improvements can be implemented based on the knowledge of those skilled in the art. .

It is a figure which shows a part of vehicle containing the vehicle control apparatus which is one Embodiment of this invention. It is a circuit diagram showing the hydraulic braking device contained in the said vehicle. It is a figure which shows notionally the hydraulic control valve (included in a vehicle control apparatus) contained in the said hydraulic braking device. It is a flowchart showing a part (control program at the time of engine stop) of the drive source stop control program memorize | stored in ROM of the engine control apparatus contained in the said vehicle control apparatus. It is a flowchart showing a part (control program at the time of engine restart) of the drive source stop control program memorize | stored in ROM of the engine control apparatus contained in the said vehicle control apparatus. It is a flowchart showing a part of said engine restart time control program. In the said vehicle control apparatus, it is a figure which shows the relationship between the inclination of the road surface where the vehicle has stopped, and the inclination angle with respect to the road surface of a vehicle body. It is a flowchart showing a part (control program at the time of engine restart) of the drive source stop control program memorize | stored in ROM of the engine control apparatus contained in the vehicle control apparatus which is another one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Engine 12: Transmission 14: Motor generator 20: Engine control device 22: Injector 48: Shift lever 80: Hydraulic pressure control valve 92: Pump 104,108: Electromagnetic on-off valve 110: Power pressurization device 152: Shift position sensor 158: Vehicle height sensor 160: Acceleration sensor 162: Engine stop permission switch 184: Brake switch 188: Wheel cylinder hydraulic pressure sensor

Claims (7)

A drive source control device that automatically stops and automatically restarts the drive source when a predetermined drive source stop condition is satisfied while the vehicle is stopped;
A vehicle control device including a braking force control device for controlling a braking force applied to the vehicle,
When the drive source is restarted by the drive source control device and an operation for instructing start of the vehicle is performed by the driver, the braking force control device shifts the braking force to the shift operation device of the vehicle. A vehicle control device including a shift operation state corresponding braking force decrease control unit that decreases a pattern according to a type of an operation state.   2. The vehicle control device according to claim 1, wherein the shift operation state corresponding braking force reduction control unit includes means for reducing the braking force with a gradient corresponding to a type of a shift operation state of the shift operation device.   The vehicle control according to claim 1, wherein the shift operation state corresponding braking force reduction control unit includes means for starting the reduction of the braking force from a time determined according to a type of a shift operation state of the shift operation device. apparatus. The vehicle control device shifts and outputs the rotation speed of the output shaft of the drive source, and controls the transmission section to thereby control the rotation speed of the output shaft of the drive source to rotate the output shaft of the transmission section. A drive transmission control device including a transmission control unit that sets a transmission ratio that is a value divided by a number to a magnitude corresponding to a shift operation state of the shift operation device;
When the shift operation state corresponding braking force reduction control unit has a gear ratio corresponding to the shift operation state smaller than a predetermined set ratio, the control is performed after the control of the transmission unit in the drive transmission control device is finished. A braking force reduction start unit for starting the reduction of the braking force before the control of the transmission unit in the drive transmission control device is completed when the reduction of power is started and the speed ratio is larger than the set ratio; The vehicle control device according to claim 1 or 2.   3. The vehicle according to claim 1, wherein the shift operation state corresponding braking force reduction control unit includes means for starting the reduction of the braking force from a time determined according to an operation type instructing the driver to start. Control device.   When the accelerator operation is performed as an operation for instructing the driver to start, the shift operation state corresponding braking force control unit decreases the braking force in accordance with the accelerator operation and instructs the driver to start. The vehicle control device according to claim 5, further comprising means for starting a decrease in the braking force after a set time has elapsed after the brake operation is released when a brake release operation is performed as the operation to perform. While the drive source is stopped by the drive source control device, the braking force control device can change the braking force according to the environment in which the vehicle is placed, such as a road surface gradient and a load load. The vehicle control device according to any one of claims 1 to 6, further comprising a braking force control unit at the time of stopping the driving source, which is controlled to a size suitable for maintaining the stopped state.

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