JP6637006B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device for stopping a vehicle, which automatically stops and restarts an internal combustion engine when the vehicle stops, and brakes the vehicle in a stopped state.

  2. Description of the Related Art As a conventional control device for a vehicle of this type, for example, a control device disclosed in Patent Document 1 proposed by the present applicant is known. In this control device, the internal combustion engine is of a so-called idle stop type that is automatically stopped and restarted when the vehicle stops. The vehicle includes a hydraulic foot brake that brakes the vehicle according to the operation state of the brake pedal during normal driving, and an electric parking brake that brakes and holds the vehicle in a stopped state when the internal combustion engine is automatically stopped. .

  In this control device, the internal combustion engine is automatically stopped when a predetermined stop condition (including that the vehicle speed is equal to or lower than a predetermined value and a brake pedal is depressed) is satisfied. When the opening of the accelerator pedal is equal to or greater than the predetermined opening, the internal combustion engine is restarted on the assumption that the restart condition is satisfied. Further, during automatic stop, when the braking force of the foot brake decreases in response to the release of the brake pedal, the parking brake automatically operates to compensate for this. Thereafter, the parking brake is released when the internal combustion engine is restarted. At that time, the start time and end time of the release are set according to the road surface gradient.

Japanese Patent No. 5703158

  In the above-described control device, the parking brake performs an operation of automatically braking and holding the stopped vehicle so as not to move. As another conventional control device, as another mode other than the electric parking brake, for example, a brake / holding operation is automatically performed by operating a valve of a hydraulic circuit of a hydraulic brake. (Hereinafter, these are collectively referred to as “auto brake hold”). Further, some conventional control devices include a standby switch for permitting or prohibiting the operation of the automatic brake hold. The standby switch is operated by the driver of the vehicle, and in the off state, the auto brake hold is prohibited. When the standby switch is turned on, the automatic brake hold is permitted, and the automatic brake hold is executed when a condition such as the vehicle being stopped is satisfied.

  However, when such a standby switch is applied to the parking brake of the conventional control device described above, the automatic stop of the internal combustion engine is performed regardless of the on / off state of the standby switch as long as the predetermined stop condition described above is satisfied. Instead, it is executed uniformly. For this reason, when the standby switch is on, it is necessary to simultaneously restart the internal combustion engine and release the automatic brake hold when starting from automatic stop, and the time lag between them becomes longer, This may give the impression of a slow start, and there is room for improvement in this regard.

  The present invention has been made to solve such a problem, and appropriately performs automatic stop of an internal combustion engine in accordance with permission or prohibition of operation of a braking device that brakes and holds a vehicle in a stopped state. Accordingly, it is an object of the present invention to provide a control device for a vehicle, which can realize good startability of the vehicle and improvement in fuel efficiency by automatic stop.

In order to achieve this object, the invention according to claim 1 of the present application automatically stops the internal combustion engine 3 mounted on the vehicle V when a predetermined stop condition is satisfied, and when the predetermined restart condition is satisfied. A control device for a vehicle that automatically restarts when it is established, a braking device 5 for braking and holding the vehicle V in a stopped state, and an operation of the braking device 5 operated by a driver of the vehicle V Operation permission / prohibition means (ABH standby switch 70 in the embodiment (hereinafter the same in this section)) for permitting or prohibiting the operation of the brake device 5 and the operation of the brake device 5 are prohibited. And a stop condition changing means (ECU 2, step 9 in FIG. 5, step 9A in FIG. 7, step 22 in FIG. 9) for changing the stop condition to a more strict side as compared with I do.

  This internal combustion engine is mounted on a vehicle, and is automatically stopped when a predetermined stop condition is satisfied, and then automatically restarted when a predetermined restart condition is satisfied. The control is applied. Further, in this control device, the vehicle is braked and held in a stopped state by the braking device, and the operation of the braking device is permitted or prohibited by the operation permission / prohibition means operated by the driver.

  In such a configuration, when the operation of the braking device is permitted, if the automatic stop of the internal combustion engine is also executed, both the restart of the internal combustion engine and the release of the braking by the braking device are performed when the vehicle starts thereafter. It is necessary to perform the operation, and the start lag may be deteriorated due to an increase in the time lag therebetween. On the other hand, when the operation of the braking device is prohibited, even if the automatic stop of the internal combustion engine is executed, the influence on the startability is small.

From such a viewpoint, according to the present invention , the stop condition is changed to a stricter condition when the operation of the braking device is permitted as compared with when the operation of the braking device is prohibited . Thereby, when the operation of the braking device is permitted, the stop condition is hardly satisfied, and the automatic stop is hardly executed. As a result, the time lag at the time of starting the vehicle is suppressed, so that a good startability of the vehicle can be obtained. On the other hand, when the operation of the braking device is prohibited, the stop condition is easily maintained, and the automatic stop is easily executed. Therefore, advantages such as improvement in fuel efficiency due to the automatic stop can be favorably obtained.

  According to a second aspect of the present invention, in the vehicle control device according to the first aspect, the predetermined stop condition is a condition that the stroke SBP of the brake pedal 11 of the vehicle V is equal to or more than a predetermined amount (threshold value SREF). The stop condition changing means includes changing the predetermined amount to an increased side (second predetermined amount SH) when the operation of the braking device 5 is permitted (step 9 in FIG. 5).

  According to this configuration, the automatic stop of the internal combustion engine is executed on condition that the stroke of the brake pedal is equal to or more than a predetermined amount (one of the stop conditions). When the operation of the braking device is permitted, the above-mentioned predetermined amount is changed to an increased side, that is, the stop condition is changed to a more severe side. Therefore, when the operation of the braking device is permitted, the stop condition is hardly satisfied, and the automatic stop is hardly executed, so that a good startability of the vehicle can be ensured. Can be obtained.

  In this configuration, the changed stop condition relates to the degree of depression of the brake pedal operated by the driver when stopping the vehicle. From this relationship, the driver of the vehicle can select execution or prohibition of automatic stop when the braking device operates by adjusting the stroke of the brake pedal. For example, when priority is given to the startability of the vehicle, the automatic stop can be prohibited by maintaining the stroke of the brake pedal in a small state smaller than a predetermined amount. On the other hand, if it is desired to prioritize the improvement of fuel efficiency by the automatic stop over the startability of the vehicle, the automatic stop can be executed by increasing the stroke of the brake pedal to a predetermined amount or more.

  According to a third aspect of the present invention, in the vehicle control device according to the first aspect, the predetermined stop condition is that a brake fluid pressure (master cylinder pressure PMC) generated according to the degree of depression of the brake pedal 11 of the vehicle V. The stop condition changing means includes a condition that the pressure is equal to or higher than a predetermined pressure (threshold value PREF), and when the operation of the braking device 5 is permitted, the stop condition changing means changes the predetermined pressure to an increased side (second predetermined pressure PH). (Step 9A in FIG. 7).

  According to this configuration, the automatic stop of the internal combustion engine is executed on condition that the brake fluid pressure generated according to the degree of depression of the brake pedal is equal to or higher than a predetermined pressure (one of the stop conditions). Further, when the operation of the braking device is permitted, the predetermined pressure is changed to an increased side, and the stop condition is changed to a more severe side. Therefore, when the operation of the braking device is permitted, the stop condition is hardly satisfied, and the automatic stop is hardly executed, so that a good startability of the vehicle can be ensured. Can be obtained. Further, by adjusting the brake fluid pressure through the degree of depression of the brake pedal by the driver, execution or prohibition of automatic stop when the brake device operates can be selected as in the second aspect.

  According to a fourth aspect of the present invention, in the vehicle control device according to the first aspect, the predetermined stop condition includes a pedal depression condition that the brake pedal 11 of the vehicle V is in a predetermined depression state, and the stop condition changing means. Is characterized in that when the operation of the braking device 5 is permitted, the pedal depression condition is changed to a condition that a predetermined depression state continues for a predetermined time TREF (step 22 in FIG. 9).

  According to this configuration, the automatic stop of the internal combustion engine is executed on condition that the brake pedal is in a predetermined depression state (one of the stop conditions). Further, when the operation of the braking device is permitted, the pedal depression condition is changed to a condition that a predetermined depression state continues for a predetermined time, and the stop condition is changed to a stricter condition. Therefore, when the operation of the braking device is permitted, the stop condition is hardly satisfied, and the automatic stop is hardly executed, so that a good startability of the vehicle can be ensured. Can be obtained. Further, by adjusting the duration of the depressed state of the brake pedal by the driver, it is possible to select execution or prohibition of automatic stop when the brake device operates, as in the second and third aspects.

  According to a fifth aspect of the present invention, in the vehicle control device according to the fourth aspect, the predetermined depression state in the pedal depression condition is a state in which the stroke SBP of the brake pedal 11 is equal to or more than a predetermined amount, and the depression of the brake pedal 11. The brake fluid pressure (master cylinder pressure PMC) generated in response to the pressure is equal to or higher than a predetermined pressure, and the brake switch 69 is turned on to indicate that the brake pedal 11 is depressed. I do.

  According to this configuration, the predetermined depressed state in the pedal depressing condition is one of a state in which the stroke SBP of the brake pedal is equal to or more than a predetermined amount, a state in which the brake fluid pressure is equal to or more than a predetermined pressure, and an ON state of the brake switch Therefore, the above-described effect according to claim 4 can be appropriately obtained.

Further, another invention disclosed by the present application automatically stops the internal combustion engine 3 mounted on the vehicle V when a predetermined stop condition is satisfied, and automatically stops when a predetermined restart condition is satisfied. A braking device 5 for braking and holding the vehicle V in a stopped state, and an operation that is operated by a driver of the vehicle V and permits or inhibits the operation of the braking device 5. A permission / prohibition means (ABH standby switch 70) and an automatic stop prohibition means (ECU2, FIG. 11) for prohibiting the automatic stop of the internal combustion engine 3 irrespective of the stop condition when the operation of the braking device 5 is permitted. Step 13).

  In the vehicle control device according to the present invention, the internal combustion engine is automatically stopped and restarted when predetermined stop conditions and restart conditions are satisfied, similarly to the first aspect of the invention. Further, the vehicle is braked and held in a stopped state by the brake device, and the operation of the brake device is permitted or prohibited by the operation permission / prohibition means operated by the driver.

  According to the present invention, when the operation of the braking device is permitted, the automatic stop of the internal combustion engine is prohibited regardless of the stop condition. Thus, when the vehicle starts, the internal combustion engine does not need to be restarted, and only the operation of the braking device is released, so that the same good startability as a vehicle without an automatic stop function can be secured. .

It is a figure showing roughly vehicles to which the present invention is applied. FIG. 2 is a circuit diagram illustrating a configuration of a braking device. It is sectional drawing which shows the schematic structure of an electric brake. It is a block diagram showing a control device of a vehicle. 5 is a flowchart illustrating a control process of the vehicle according to the first embodiment. 6 is a timing chart showing an operation example obtained by the control processing of FIG. It is a flowchart which shows the control processing of the vehicle by 2nd Embodiment. 8 is a timing chart illustrating an operation example obtained by the control processing of FIG. 7. It is a flowchart which shows the control processing of the vehicle by 3rd Embodiment. 10 is a timing chart illustrating an operation example obtained by the control processing of FIG. 9. It is a flowchart which shows the control processing of the vehicle by 4th Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows a vehicle V to which the present invention is applied. As shown in FIG. 1, a vehicle V is a front-wheel-drive four-wheel vehicle having left and right front wheels WFL, WFR and left and right rear wheels WRL, WRR (hereinafter, collectively referred to as “wheels W”). An internal combustion engine (hereinafter referred to as “engine”) 3 mounted on the front part, an automatic transmission 4 for shifting the power of the engine 3, a braking device 5 for braking the vehicle V (see FIG. 2), and a braking device 5 and an electric brake 20 for braking the vehicle V.

  When the vehicle V is stopped, the engine 3 is automatically stopped when a predetermined stop condition described later is satisfied, and is automatically restarted from this stopped state when a predetermined restart condition is satisfied. The so-called idle stop control is applied.

  The automatic transmission 4 includes a torque converter connected to a crankshaft of the engine 3, a shift lever capable of selecting a plurality of shift positions, and a gear mechanism (none of which is shown) capable of switching to a plurality of shift speeds. Have. The output shaft (not shown) of the torque converter of the automatic transmission 4 is connected to the left and right front wheels WFL and WFR via a final reduction mechanism 8 and left and right drive shafts 9 and 9, whereby the engine 3 Is transmitted to the front wheels WFL, WFR.

  As shown in FIG. 2, the braking device 5 is of a hydraulic type using a brake fluid such as hydraulic oil, and is provided on a brake pedal 11, a master cylinder 12, a hydraulic circuit 13, and each wheel W. And a disc brake 14 and the like. The disc brake 14 includes a disc 15 (see FIG. 1) integrated with the wheel W, a pair of movable brake pads (not shown) arranged on both sides thereof, and a piston (not shown) for driving the brake pads. ) And a wheel cylinder 16. When the driver of the vehicle V depresses the brake pedal 11, the brake hydraulic pressure generated in the master cylinder 12 is supplied to the wheel cylinder 16 via the hydraulic circuit 13, so that the brake pad is driven and the disc 15 The vehicle V is braked by being pinched. Details of the configuration and operation of the braking device 5 will be described later.

  The electric brakes 20 are provided on the left and right rear wheels WRL, WRR, respectively. As shown in FIG. 3, the electric brake 20 is screwed into the caliper body 21 provided integrally with the vehicle body (not shown) of the vehicle V, a nut 22 fixed in the caliper body 21, and the nut 22. It has a screw 23 movable in the axial direction, a pair of brake pads 24a and 24b housed in a concave portion 21a of the caliper body 21, and a brake motor 25 having one end of the screw 23 and a rotating shaft 25a connected thereto. . One brake pad 24a is attached to the wall surface of the recess 21a, and the other brake pad 24b is attached to the other end of the screw 23. The disc 15 of the disc brake 14 is located between the brake pads 24a and 24b. Is arranged.

  With the above configuration, when the brake motor 25 rotates forward, the screw 23 moves toward the disk 15 while rotating, so that the brake pad 24b moves together therewith, and the disk 15 is sandwiched between the brake pad 24a and the brake pad 24a. Thus, the rear wheels WRL, WRR are braked. When the brake motor 25 rotates in the reverse direction from this state, the brake pad 24b moves toward the brake motor 25 by the action opposite to that described above and separates from the disk 15, whereby the braking of the rear wheels WRL and WRR is released. Such an operation of the electric brake 20 is performed in accordance with an operation state of an electric brake switch (not shown) provided in a driver seat of the vehicle V, and a control signal from an ECU (electronic control unit) 2 described later. Is controlled by

  Next, the configuration of the above-described braking device 5 will be described in detail with reference to FIG. The master cylinder 12 of the braking device 5 is of a tandem type having two hydraulic chambers and a piston (both not shown). Brake fluid is supplied from a reservoir 31 to each hydraulic chamber, and one piston is connected to the brake pedal 11. A brake booster 32 is provided between the brake pedal 11 and the master cylinder 12. The brake booster 32 generates an assist force acting on the piston by using a negative pressure generated in the intake pipe when the engine 3 is operating, and assists the depression force (operation force) of the brake pedal 11.

  When the brake pedal 11 is operated, two pistons move to pressurize the brake fluid in each hydraulic chamber, thereby generating a brake fluid pressure corresponding to the depression force of the brake pedal 11 assisted by the brake booster 31. Then, it is output from the first output port 33a and the second output port 33b communicating with each hydraulic chamber.

  The hydraulic circuit 13 of the braking device 5 includes a first hydraulic circuit 13A connected between the first output port 33a and the wheel cylinders 16 of the left front wheel WFL and the right rear wheel WRR, and a second output port 33b. And a second hydraulic circuit 13B connected between the right front wheel WFR and the wheel cylinders 16 of the left rear wheel WRL.

  Since these two hydraulic circuits 13A and 13B have the same configuration, the configuration will be described below by taking the first hydraulic circuit 13A as an example. A first liquid passage 41 is connected to the first output port 33a of the master cylinder 12. A first control valve 42 and a second control valve 43 for VSA (Vehicle Stability Assist) are provided in parallel on the downstream side of the first liquid passage 41, and the first control valve 42 further includes a check valve 44. Are provided in parallel.

  The first control valve 42 is a normally-open solenoid valve that allows a bidirectional flow of the brake fluid, and the downstream side thereof is connected to the reservoir 46 via the second fluid passage 45. The check valve 44 is arranged to allow the flow of the brake fluid from the upstream side to the downstream side of the first control valve 42.

  The second control valve 43 is a normally closed solenoid valve that allows only the flow of the brake fluid from the upstream side, and the downstream side thereof is connected to the second liquid path 45 via the third liquid path 47. It is connected. The second fluid path 45 is provided with a check valve 48 at a position closer to the reservoir 46 than the connection part of the third fluid path 47 to allow the flow of the brake fluid from the reservoir 46 side.

  Two fourth fluid paths 49, 49 are connected in parallel to the second fluid path 45, and these fourth fluid paths 49, 49 are connected to the wheel cylinders 16 of the left front wheel WFL and the right rear wheel WRR. , 16 respectively. In each fourth liquid passage 49, an inflow valve 50 and a check valve 51 are provided in parallel. The inflow valve 50 is formed of a normally-open solenoid valve that allows a bidirectional flow of the brake fluid. The check valve 51 is arranged so as to allow the flow of the brake fluid from the downstream side to the upstream side of the inflow valve 50.

  Further, a fifth liquid path 52 branches from a downstream side of the inflow valve 50 of each fourth liquid path 49, and an outflow valve 53 is provided in each fifth liquid path 52. The outflow valve 53 is a normally closed solenoid valve that allows only the flow of the brake fluid from the inflow valve 50 side. The fifth liquid paths 52, 52 join the sixth liquid path 54, and the sixth liquid path 54 is connected to the reservoir 46 side of the check valve 48 of the second liquid path 45.

  A hydraulic pump 55 is provided in the second hydraulic passage 45 at a position on the side opposite to the reservoir 46 with respect to the connection portion of the third hydraulic passage 47, and the hydraulic pump 55 is connected to a hydraulic motor 56. The hydraulic motor 56 is driven by electric power supplied from the battery 7 based on a drive signal from the ECU 2, and thereby the hydraulic pump 55 is driven.

  Next, the operation of the braking device 5 having the above-described configuration will be described. In a normal driving state of the vehicle V and the engine 3, the operation mode of the braking device 5 is set to the normal mode shown in FIG. In this normal mode, the first control valve 42, the second control valve 43, the inflow valve 50, and the outflow valve 53 of the braking device 5 are all controlled to be in a non-excited state, and the hydraulic motor 56 and the hydraulic pump 55 Is stopped.

  In this normal mode, when the brake pedal 11 is depressed, a brake fluid pressure (master cylinder pressure PMC) generated in accordance with the sum of the depression force and the assist force by the brake booster 32 is generated in the master cylinder 12. . This brake fluid pressure is output from the first and second output ports 33a and 33b to the first fluid passages 41 of the first and second hydraulic circuits 13A and 13B, and furthermore, the first control valve 42, the inflow valve 50 and The fluid is supplied to the wheel cylinder 16 of each wheel W via the fourth fluid path 49. As a result, the disc brake 14 operates on each wheel W, and the vehicle V is braked with a braking force corresponding to the wheel cylinder pressure PWC.

  When increasing the braking force of the vehicle V, the operation mode of the braking device 5 is set to the pressurization mode. Although not shown, in the pressurizing mode, the first control valve 42 is excited and closed, the second control valve 43 is excited and opened, and the hydraulic motor 56 is driven from the control state in the normal mode. The hydraulic pump 55 is operated. As a result, the brake fluid is pumped up from the reservoir 46 by the hydraulic pump 55 and is pressurized, and the pressurized brake fluid pressure is transmitted through the second fluid passage 45, the inflow valve 50, and the fourth fluid passage 49. By being supplied to the wheel cylinder 16, the wheel cylinder pressure PWC increases, and the braking force of the vehicle V increases.

  When the increased braking force of the vehicle V is maintained after the above-described pressurizing mode, the operation mode of the braking device 5 is set to the holding mode. Although not shown, in the holding mode, the second control valve 43 is de-energized and closed from the control state in the pressurizing mode. As a result, the first fluid passage 41 leading to the master cylinder 12 is closed by the first control valve 42, and the return of the brake fluid from the second fluid passage 45 to the reservoir 46 is prevented by the check valve 48. The outflow of brake fluid from the wheel cylinder 16 is prevented. Thereby, the wheel cylinder pressure PWC is held, and the braking force of the vehicle V is held.

  As described above, the braking device 5 is configured to increase the braking force of the vehicle V by transmitting the brake hydraulic pressure pressurized by the hydraulic pump 55 driven by the hydraulic motor 56. . On the other hand, the above-described electric brake 20 is configured to obtain a braking force by rotating and moving the screw 23 by the brake motor 25. Therefore, when the two are compared, the response time from when power is supplied to the motor (the hydraulic motor 56 or the brake motor 25) to when the braking force is actually generated is shorter in the braking device 5. That is, the braking device 5 has a characteristic that the responsiveness is higher than that of the electric brake 20.

  For this reason, in the present embodiment, the automatic brake hold of the vehicle V (the operation of automatically braking and holding the stopped vehicle V so as not to move) is performed by using the braking device 5 and the operation mode described above. This is performed by setting the pressure / hold mode. This holding mode is released when the vehicle V starts, and returns to the above-described normal mode. In the following description, the auto brake hold is appropriately referred to as “ABH”.

  Further, the vehicle V and the engine 3 are provided with various sensors and switches as described below in order to detect their operation state and the like, and the detection signals of the sensors and ON / OFF of the switches are provided. The signal is input to the ECU 2 (see FIG. 4).

  The master cylinder pressure sensor 61 is provided in the first liquid passage 41 and detects the master cylinder pressure PMC. The crank angle sensor 62 outputs a CRK signal indicating the rotation speed of the crankshaft of the engine 3, and the wheel speed sensor 63 outputs a VW signal indicating the rotation speed of each wheel W. The ECU 2 calculates the rotational speed NE of the engine 3 based on the CRK signal, and calculates the vehicle speed VP, which is the speed of the vehicle V, based on the VW signal. The accelerator opening sensor 64 detects an opening (hereinafter referred to as “accelerator opening”) AP of an accelerator pedal (not shown) of the vehicle V.

  The stroke sensor 65 detects a stroke (hereinafter referred to as “pedal stroke”) SBP of the brake pedal 11. Further, the shift position sensor 66 detects the shift position SP of the shift lever, and the voltage sensor 67 detects the voltage of the battery 7 (hereinafter referred to as “battery voltage”) VB. The ECU 2 calculates the remaining charge SOC of the battery 7 based on the battery voltage VB and the like.

  The ignition switch 68 outputs a signal indicating the on / off state, the brake switch 69 outputs an on / off signal indicating whether the brake pedal 11 is depressed, and the ABH standby switch 70 outputs the on / off signal. Outputs a signal indicating the OFF state. The ABH standby switch 70 is provided on a control panel or the like of the vehicle V, and is operated by a driver of the vehicle V when permitting the operation of the above-described auto brake hold.

  The ECU 2 is configured by a microcomputer including a CPU, a RAM, a ROM, an input interface (all not shown), and the like. The ECU 2 performs idle stop control of the engine 3 and automatic control of the vehicle V based on a control program or the like stored in a ROM according to the detection signals of the various sensors 61 to 67 and the on / off signals of the switches 68 to 70 described above. Execute brake hold control and so on. In the embodiment, the ECU 2 corresponds to a stop condition changing unit and an automatic stop prohibiting unit.

  Next, a vehicle control process according to the first embodiment of the present invention will be described with reference to FIG. This control process controls the auto-brake hold of the vehicle V and the idle stop of the engine 3 when the vehicle V stops, and is executed by the ECU 2 at predetermined intervals.

  In this process, first, in step 1 (illustrated as “S1”; the same applies hereinafter), it is determined whether or not the ABH standby switch 70 is on. If the answer is NO and the operation of the ABH is prohibited, the ABH is deactivated accordingly, and the idle stop is controlled in step 2 and subsequent steps.

  First, in step 2, the threshold value SREF of the pedal stroke SBP is set to a relatively small first predetermined amount SL (for example, 20%). Next, it is determined whether the vehicle speed VP is 0 and whether the brake switch (SW) 69 is on (steps 3 and 4). When any of these answers is NO, that is, when the vehicle V is not stopped or the brake pedal 11 is not depressed, it is determined that the idle stop condition is not satisfied and the idle stop (I / S) Is maintained in a non-operating state (step 5), and this processing ends.

  On the other hand, if the answers in steps 3 and 4 are both YES and the vehicle V is at a standstill and the brake pedal 11 is depressed, the pedal stroke SBP becomes equal to the threshold value SREF ( = The first predetermined amount SL) is determined (step 6). If the answer is NO, it is determined that the idle stop condition is not satisfied, and the routine proceeds to step 5, and the idle stop is maintained in a non-operating state.

  When the answer to the step 6 is YES and the pedal stroke SBP is equal to or larger than the threshold value SREF, it is determined whether or not another idle stop condition is satisfied (step 7). The “other idle stop conditions” include, for example, that the detected shift position SP of the shift lever is other than P, R, and N, and that the calculated remaining battery charge SOC is a predetermined value or more. included. When the answer to step 7 is NO, the process proceeds to step 5 and the idle stop is maintained in a non-operating state.

  If the answer to the above step 7 is YES, it is determined that all the idle stop conditions are satisfied, the idle stop is activated (step 8), and the present process is terminated. The operation of the idle stop is performed by stopping the supply of fuel to the fuel injection valve 8.

  On the other hand, if the answer to the step 1 is YES and the operation of the ABH is permitted, the ABH and the idle stop are controlled in step 9 and subsequent steps accordingly.

  First, at step 9, the threshold value SREF of the pedal stroke SBP is set to a second predetermined amount SH (for example, 50%) larger than the first predetermined amount SL. Next, as in steps 3 and 4, it is determined whether the vehicle speed VP is 0 and whether the brake switch 69 is on (steps 10 and 11). If any of these answers is NO, it is determined that neither the ABH execution condition nor the idle stop condition is satisfied, and both the ABH and the idle stop are maintained in a non-operation state (steps 12 and 13), and the present processing is performed. To end.

  On the other hand, if the answers in steps 10 and 11 are both YES, it is determined that the ABH execution condition is satisfied and the ABH is activated (step 14). The operation of the ABH is performed by sequentially setting the operation mode of the braking device 5 to the above-described pressurizing mode and the holding mode so that the brake hydraulic pressure pressurized by the hydraulic pump 55 driven by the hydraulic motor 56 is applied to the wheel. This is performed by supplying the fuel to the cylinder 16 to increase the braking force of the vehicle V and holding the increased braking force, so that the vehicle V is kept stationary.

  Next, it is determined whether or not the pedal stroke SBP is equal to or greater than the threshold value SREF (= second predetermined amount SH) set in step 9 (step 15). If the answer is NO, it is determined that the idle stop condition is not satisfied, and the routine proceeds to step 13, where the idle stop is maintained in a non-operating state.

  When the answer to step 15 is YES and the pedal stroke SBP is equal to or greater than the threshold value SREF, it is determined whether another idle stop condition is satisfied as in step 7 (step 16). If the answer is no, the process proceeds to step 13 and the idle stop is maintained in a non-operating state. On the other hand, if the answer to step 16 is YES, it is determined that all the idle stop conditions are satisfied, the idle stop is activated (step 17), and the present process is terminated.

  Although not shown, in the above-described ABH and idle stop operating states, for example, when the accelerator pedal is depressed and the accelerator opening AP exceeds a predetermined value, the engine 3 is restarted on the assumption that the restart condition is satisfied. At the same time, the operation of the ABH is released, whereby the vehicle V is started. The restart of the engine 3 is performed by injecting fuel from the fuel injection valve 8 while performing cranking by the starter motor 6. The release of the operation of the ABH is performed by returning the operation mode of the braking device 5 to the normal mode.

  FIG. 6 shows an operation example obtained by the control processing of FIG. In this example and an operation example described later, it is assumed that other idle stop conditions determined in step 7 in FIG. 5 and the like are satisfied. In this example, at time t2, the brake pedal 11 is depressed, and accordingly, the brake switch 69 is switched to the ON state, the pedal stroke SBP is gradually increased, and the vehicle speed VP is gradually reduced.

  The broken line in FIG. 6 shows the operation when the ABH standby switch 70 is off. In this case, ABH is deactivated, and the threshold value SREF of the pedal stroke SBP is set to a smaller first predetermined amount SL (step 2 in FIG. 5). Then, when the vehicle speed VP becomes 0 (t3), and thereafter, when the pedal stroke SBP reaches the first predetermined amount SL (t4), the answers to steps 3, 4 and 6 become YES, and the idle stop condition is satisfied. Is established, the operation of the idle stop is started.

  On the other hand, the solid line with respect to the broken line in FIG. 6 shows the operation when the ABH standby switch 70 is turned on at time t1. In this case, the threshold value SREF of the pedal stroke SBP is set to the larger second predetermined amount SH (step 9). Further, when the vehicle speed VP becomes 0 (t3), the answers to Steps 10 and 11 become YES, and the ABH operation is started assuming that the ABH execution condition is satisfied.

  Also, unlike the case where the ABH standby switch 70 is in the off state, even if the pedal stroke SBP reaches the first predetermined amount SL (t4), the idle stop is maintained in the inactive state, and thereafter, the pedal stroke SBP further increases. When the second predetermined amount SH has been reached (t5), the answer to step 15 is YES, and the idle stop operation is started, assuming that the idle stop condition is satisfied.

  As described above, according to the present embodiment, as one of the idle stop conditions, the condition that the pedal stroke SPB is equal to or greater than the threshold value SREF is set, and the ABH standby switch 70 is turned off and the ABH When the operation is prohibited, the threshold value SREF is set to the smaller first predetermined amount SL. With this setting, when the operation of the ABH is prohibited, the idle stop condition in which the pedal stroke SPB is equal to or larger than the threshold value SREF is easily satisfied, and the idle stop is easily executed. Can be obtained favorably.

  On the other hand, when the ABH operation is permitted while the ABH standby switch 70 is on, the threshold value SREF is set to the larger second predetermined amount SH. With this setting, when the operation of the ABH is permitted, the idle stop condition in which the pedal stroke SPB is equal to or larger than the threshold value SREF is hardly satisfied, and the idle stop is hardly executed. As a result, the time lag at the time of the start of the vehicle V is suppressed, so that good startability of the vehicle V can be ensured.

  The driver can adjust the pedal stroke SBP to select execution or prohibition of the idle stop when the ABH operates. For example, when it is desired to give priority to the startability of the vehicle V, the idling stop is prohibited by maintaining the pedal stroke SBP to be less than the second predetermined amount SH, and the fuel efficiency due to the idle stop is more than the startability of the vehicle V. When priority is given to improvement, idle stop can be executed by increasing the pedal stroke SPB to the second predetermined amount SH or more.

  Next, a vehicle control process according to a second embodiment of the present invention will be described with reference to FIG. This control process differs from the control process of the first embodiment (FIG. 5) in that the master cylinder pressure PMC is used instead of the pedal stroke SBP as one of the idle stop conditions, and the other parts are the same. is there. Therefore, in FIG. 7, portions having the same contents as those in FIG. 5 are denoted by the same step numbers, and the following description will focus on different portions. This control process is also executed by the ECU 2 at predetermined intervals.

  In this process, first, in step 1, it is determined whether or not the ABH standby switch 70 is on. If the answer is NO, ABH is deactivated, and in step 2A, the master cylinder pressure PMC is reduced. The threshold value PREF is set to a relatively small first predetermined pressure PL.

  Next, it is determined whether or not the vehicle speed VP = 0 and whether or not the brake switch 69 is on (steps 3 and 4), and the master cylinder pressure PMC is set to the threshold value PREF (step 3A). = First predetermined value PL) or more (step 6A), and also determines whether another idle stop condition is satisfied (step 7). When any of these answers is NO, it is determined that the idle stop condition is not satisfied, and the idle stop is maintained in the non-operation state (step 5). When all these answers are YES, the idle stop condition is satisfied. Assuming that the condition is satisfied, the idle stop is operated (step 8).

  On the other hand, when the answer to the step 1 is YES, in a step 9A, the threshold value PREF of the master cylinder pressure PMC is set to a second predetermined pressure PH which is larger than the first predetermined pressure PL. Next, as in the first embodiment, it is determined whether the vehicle speed VP = 0 and whether the brake switch 69 is on (steps 10 and 11). If any of these answers is NO, it is determined that neither the ABH execution condition nor the idle stop condition is satisfied, and the ABH and the idle stop are maintained in the inactive state, respectively (steps 12 and 13). On the other hand, if the answers in steps 10 and 11 are both YES, it is determined that the ABH execution condition is satisfied and the ABH is activated (step 14).

  Next, it is determined whether or not the master cylinder pressure PMC is equal to or higher than the threshold value PREF (= second predetermined pressure PH) set in step 9A (step 15A). Assuming that the condition is not satisfied, the idle stop is maintained in the inactive state. If the answer to step 15A is YES and the master cylinder pressure PMC is equal to or higher than the threshold value PREF, it is determined whether another idle stop condition is satisfied (step 16). If the answer is NO, the idle stop is set to the non-operation state. maintain. On the other hand, if the answer to step 16 is YES, it is determined that the idle stop condition is satisfied, and the idle stop is activated (step 17).

  FIG. 8 shows an operation example obtained by the control processing of FIG. In this example, as the brake pedal 11 is depressed at time t12, the brake switch 69 is switched to the ON state, and the master cylinder pressure PMC gradually increases as the depression force of the brake pedal 11 increases, The vehicle speed VP is gradually decreasing.

  When the ABH standby switch 70 is off, ABH is deactivated and the threshold value PREF of the master cylinder pressure PWC is set to a smaller first predetermined pressure PL, as indicated by a broken line in FIG. (Step 2A in FIG. 7). Then, when the vehicle speed VP becomes 0 (t13) and the master cylinder pressure PMC reaches the first predetermined pressure PL (t14), the answers in steps 3, 4 and 6A are all YES, and the idle stop condition is satisfied. Is established, the operation of the idle stop is started.

  On the other hand, when ABH standby switch 70 is on at time t11, threshold value PREF of master cylinder pressure PWC is set to a larger second predetermined pressure PH, as indicated by the solid line with respect to the broken line (step S11). 9A). Further, when the vehicle speed VP becomes 0 (t13), the answers to Steps 10 and 11 become YES, and the ABH operation is started assuming that the ABH execution condition is satisfied.

  Also, unlike the case where the ABH standby switch 70 is in the off state, even when the master cylinder pressure PWC reaches the first predetermined pressure PL (t14), the idle stop is maintained in the non-operation state, and thereafter, the master cylinder pressure PWC further increases. When the pressure increases and reaches the second predetermined pressure PH (t15), the answer to step 15A is YES, and the idle stop operation is started assuming that the idle stop condition is satisfied.

  As described above, according to the present embodiment, as one of the idle stop conditions, the condition that the master cylinder pressure PMC is equal to or higher than the threshold value PREF is set, and the ABH standby switch 70 is turned off and the ABH Is prohibited, the threshold value PREF is set to a smaller first predetermined pressure PL. With this setting, when the operation of the ABH is prohibited, the idle stop condition in which the master cylinder pressure PMC is equal to or higher than the threshold value PREF is easily satisfied, and the idle stop is easily executed. Advantages can be obtained favorably.

  On the other hand, when ABH standby switch 70 is on and ABH operation is permitted, threshold value PREF is set to a larger second predetermined pressure PH. With this setting, when the operation of the ABH is permitted, the idle stop condition in which the master cylinder pressure PMC is equal to or higher than the threshold value PREF is difficult to be satisfied, and the idle stop is difficult to be executed. Startability can be ensured. Further, the driver adjusts the master cylinder pressure PMC through the depression force of the brake pedal 11, so that execution or prohibition of the idle stop when the ABH operates can be selected.

  Next, a vehicle control process according to a third embodiment of the present invention will be described with reference to FIG. This control process is different from the control processes of the first and second embodiments (FIGS. 5 and 7) in that, as one of the idle stop conditions, the brake pedal 11 is replaced with the pedal stroke SBP and the master cylinder pressure PMC. The difference is that the duration of the stepping state is used, and the other parts are the same. Therefore, in FIG. 9, portions having the same contents as those in FIGS. 5 and 7 are denoted by the same step numbers, and the following description will focus on different portions. This control process is also executed by the ECU 2 at predetermined intervals.

  In this process, first, in step 1, it is determined whether or not the ABH standby switch 70 is on. If the answer is NO, ABH is deactivated and the vehicle speed VP = 0 or the brake switch It is determined whether 69 is in the ON state and whether other idle stop conditions are satisfied (steps 3, 4 and 7).

  When any of these answers is NO, it is determined that the idle stop condition is not satisfied, and the idle stop is maintained in the non-operation state (step 5). When all these answers are YES, the idle stop condition is satisfied. Assuming that the condition is satisfied, the idle stop is operated (step 8).

  As described above, in the present embodiment, when the ABH standby switch 70 is in the off state, the idle stop condition regarding the operation state of the brake pedal 11 is that the brake switch 69 is in the on state, that is, the brake pedal 11 is depressed. Unlike the first and second embodiments, the pedal stroke SBP and the magnitude of the master cylinder pressure PMC are not required.

  On the other hand, when the answer to step 1 is YES, it is determined whether the vehicle speed VP is 0 and whether the brake switch 69 is on (steps 10 and 11). If any of these answers is NO, it is determined that neither the execution condition of ABH nor the idle stop condition is satisfied, the timer value TM_BPON of the up-counting type is reset to 0 (step 21), and the ABH and idle stop are reset. Is maintained in a non-operation state (steps 12 and 13). On the other hand, if the answers in steps 10 and 11 are both YES, it is determined that the ABH execution condition is satisfied and the ABH is activated (step 14).

  Next, it is determined whether or not the timer value TM_BPON reset in step 21 is equal to or longer than a predetermined time TREF (step 22). When the answer is NO, that is, when the vehicle speed VP = 0 and the brake pedal 11 is depressed, When the idle state has not been continued for the predetermined time TREF, the idle stop condition is not satisfied, and the idle stop is maintained in the inactive state.

  On the other hand, if the answer to step 22 is YES, the vehicle speed VP = 0 and the state in which the brake pedal 11 is depressed continues for a predetermined time TREF, it is determined whether or not another idle stop condition is satisfied (step 16). If the answer is no, the idle stop is kept inactive. On the other hand, if the answer to step 16 is YES, it is determined that the idle stop condition is satisfied, and the idle stop is activated (step 17).

  FIG. 10 shows an operation example obtained by the control processing of FIG. In this example, as the brake pedal 11 is depressed at time t22, the brake switch 69 is switched to the ON state, and the vehicle speed VP gradually decreases.

  When the ABH standby switch 70 is in the off state, as shown by the broken line in FIG. 10, when the ABH is deactivated and the vehicle speed VP becomes 0 with the brake pedal 11 depressed (t23). ), The answers to Steps 3 and 4 are both YES, and the idle stop operation is started assuming that the idle stop condition is satisfied.

  On the other hand, when the ABH standby switch 70 is turned on at time t21, as shown by the solid line with respect to the broken line, when the vehicle speed VP becomes 0 with the brake pedal 11 being depressed (t23), step 10 is executed. And 11 are YES, the ABH execution condition is satisfied, and the operation of the ABH is started, and the counting of the timer value TM_BPON is started.

  When the timer value TM_BPON reaches the predetermined time TREF (t24), that is, when the vehicle speed VP = 0 and the state where the brake pedal 11 is depressed continues for the predetermined time TREF, the answer to step 22 is YES. That is, the idle stop operation is started assuming that the idle stop condition is satisfied.

  As described above, according to the present embodiment, the pedal depression condition, which is one of the idle stop conditions, is such that when the ABH standby switch 70 is in the off state and the operation of the ABH is prohibited, the brake pedal 11 is in the depressed state. It is in. With this setting, when the operation of the ABH is prohibited, the pedal depressing condition is easily satisfied, and the idle stop is easily executed. Therefore, advantages such as improvement of fuel efficiency by the idle stop can be obtained favorably.

  On the other hand, when the ABH standby switch 70 is in the ON state and the operation of the ABH is permitted, the pedal depression condition is changed to a condition that the depression state of the brake pedal 11 is continued for a predetermined time TREF. With this setting, when the operation of the ABH is permitted, it is difficult for the pedal depression condition to be satisfied, and it is difficult for the idle stop to be performed, so that good startability of the vehicle V can be ensured. Further, by adjusting the duration of the brake pedal 11 being depressed by the driver, it is possible to select execution or prohibition of the idle stop when the ABH operates.

  Next, a vehicle control process according to a fourth embodiment of the present invention will be described with reference to FIG. This control process is different from the control processes of the first to third embodiments (FIGS. 5, 7, and 9), and when the ABH standby switch 70 is in the ON state, regardless of the depressed state of the brake pedal 11, and the like. This is to prohibit idle stop. Therefore, in FIG. 11, the same steps as those in FIGS. 5, 7, and 9 are denoted by the same step numbers, and the following description will focus on different parts. This control process is also executed by the ECU 2 at predetermined intervals.

  In this process, first, in step 1, it is determined whether or not the ABH standby switch 70 is in an ON state, and if the answer is NO, the ABH is deactivated. The subsequent operation is exactly the same as the control processing of FIG. 9, and it is determined whether the vehicle speed VP = 0, whether the brake switch 69 is on, and whether other idle stop conditions are satisfied (step S1). 3, 4, and 7). When any one of these answers is NO, the idle stop is maintained in the non-operation state (step 5). When all these answers are YES, it is determined that the idle stop condition is satisfied, and the idle stop is determined. Is activated (step 8).

  On the other hand, when the answer to step 1 is YES, it is determined whether the vehicle speed VP is 0 and whether the brake switch 69 is on (steps 10 and 11). When any of these answers is NO, the ABH is maintained in a non-operation state (step 12), and when any of these answers is YES, it is determined that the execution condition of the ABH is satisfied and ABH is executed. Activate (step 14). Further, after step 12 or 14, the process proceeds to step 13, and the idle stop is maintained in a non-operating state. That is, when the ABH standby switch 70 is in the ON state, idle stop is unconditionally prohibited regardless of the depressed state of the brake pedal 11 or the like.

  As described above, according to the present embodiment, when the operation of the ABH is permitted, the idle stop is unconditionally prohibited. Therefore, when the vehicle V starts, the engine 3 does not need to be restarted. Since it is only necessary to cancel the operation of the vehicle, it is possible to ensure the same good startability as a vehicle having no automatic stop function.

  The present invention is not limited to the embodiments described above, but can be implemented in various modes. For example, in the third embodiment, the pedal depression condition when the operation of the ABH is permitted is changed to a condition that the depression state of the brake pedal 11 continues for a predetermined time TREF. The condition that the state in which the pedal stroke SBP is equal to or more than the predetermined amount continues for a predetermined time or the condition that the state in which the master cylinder pressure PMC is equal to or more than the predetermined pressure continues for a predetermined time may be changed. Even under these conditions, the effect of the third embodiment can be obtained similarly.

  Further, in the embodiment, ABH is performed using the hydraulic braking device 5, but it is of course possible to perform ABH using the electric brake 20 instead. In addition, the configuration of the details can be appropriately changed within the scope of the present invention.

2 ECU (stop condition changing means, automatic stop prohibition means)
3 Internal combustion engine 5 Braking device 11 Brake pedal 20 Electric brake (braking device)
70 ABH standby switch (operation permission / prohibition means)
V vehicle SBP pedal stroke (stroke of brake pedal)
SREF threshold value (predetermined amount)
SH Second predetermined amount (predetermined amount on the increasing side)
PMC master cylinder pressure (brake fluid pressure)
PREF threshold value (predetermined pressure)
PH Second predetermined pressure (predetermined pressure on the increasing side)
TREF predetermined time

Claims (5)

A vehicle control device that automatically stops an internal combustion engine mounted on a vehicle when a predetermined stop condition is satisfied, and automatically restarts when a predetermined restart condition is satisfied,
A braking device for braking and holding the vehicle in a stopped state,
An operation permission / prohibition unit that is operated by a driver of the vehicle and permits or prohibits the operation of the braking device;
When the operation of the braking device is permitted , compared to when the operation of the braking device is prohibited , a stop condition changing unit that changes the stop condition to a more severe side,
A control device for a vehicle, comprising: The predetermined stop condition includes a condition that a stroke of a brake pedal of the vehicle is equal to or more than a predetermined amount,
2. The control device according to claim 1, wherein the stop condition changing unit changes the predetermined amount to an increased side when the operation of the braking device is permitted. 3. The predetermined stop condition includes a condition that a brake fluid pressure generated according to a degree of depression of a brake pedal of the vehicle is equal to or higher than a predetermined pressure,
2. The control device according to claim 1, wherein the stop condition changing unit changes the predetermined pressure to an increased side when the operation of the braking device is permitted. 3. The predetermined stop condition includes a pedal depression condition that a brake pedal of the vehicle is in a predetermined depression state,
The stop condition changing means changes the pedal depressing condition to a condition that the predetermined depressed state continues for a predetermined time when the operation of the braking device is permitted. 2. The control device for a vehicle according to claim 1.   The predetermined depression state in the pedal depression condition includes a state in which the stroke of the brake pedal is equal to or greater than a predetermined amount, a state in which the brake fluid pressure generated in response to the depression of the brake pedal is equal to or greater than a predetermined pressure, and 5. The control device for a vehicle according to claim 4, wherein the control device is any one of an ON state of a brake switch indicating that the vehicle is in a depressed state. 6.

Images