JPH11189133A - Braking device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress unnecessary assist control intervention. SOLUTION: Assist control is started when pedal operating speed pv1 is higher than a specified speed pv10 in a step S16, pedal depressing quantity pp is larger than specified quantity pp0 in a step S18, and pedal depressing time tp is more than a specified time tp0. Assist control start is therefore judged taking account of the pedal depressing quantity and depressing time besides judging assist control start from the operating speed of the brake pedal, so that assist control is not executed in the case of an operator depressing a normal brake to expedite its rise or performing pumping brake.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle braking device.

[0002]

2. Description of the Related Art A general automobile is equipped with a booster (boost) or the like for assisting a braking force generated by depressing a brake pedal. Here, in particular, a beginner or the like may not be able to perform sufficient depression in an emergency. Therefore, there has been proposed an emergency brake assist device that assists a booster that applies a stronger braking force by increasing the auxiliary magnification of the booster.

[0003] Japanese Patent Application Laid-Open No. Hei 7-156786 discloses a system in which when the operation speed of the brake pedal is high is determined to be an emergency requiring assistance, the assist control for the booster is started.

[0004]

However, in the conventional emergency brake assist device, since the start of the assist control is determined only in accordance with the operation speed of the brake pedal, for example, as shown in FIG. When the operation speed pv1 becomes equal to or higher than the predetermined threshold value pv10, assist to the booster is started. However, in addition to the insufficient braking force required for assisting in FIG. 17, when the driver depresses so that the start-up speed becomes faster while using the normal brake, or when the pumping brake shown in FIG. In such a case, it is conceivable that the assist is started and the brakes are applied more than necessary, so that the driver may be surprised or the following vehicle may suddenly approach.

The present invention has been made in view of the above-described problems, and an object thereof is to suppress unnecessary assist intervention by judging the start of assist control of a booster in consideration of the depression amount and the depression time of a brake pedal. It is to provide a braking device for a vehicle.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and achieve the object, a vehicle braking device of the present invention has the following arrangement. That is, a brake force assisting means for assisting a braking force generated in response to a brake operation, an operation amount detecting means for detecting a brake operation amount, an operation speed detecting means for detecting a brake operation speed, and the brake operation amount Control means for starting the assisting operation of the brake force assisting means when the brake operation speed is equal to or higher than a predetermined value and the brake operation speed is equal to or higher than a predetermined speed.

The vehicle braking device of the present invention has the following configuration. That is, a brake force assisting means for assisting a braking force generated in response to a brake operation, an operation amount detecting means for detecting a brake operation amount, an operation time detecting means for detecting a brake operation time, and the brake operation amount Control means for starting the assisting operation of the braking force assisting means when the brake operation time is equal to or more than a predetermined amount and the brake operation time is equal to or longer than a predetermined time.

Further, the vehicle braking device of the present invention has the following configuration. That is, a brake force assisting means for assisting a braking force generated in response to a brake operation, an operation amount detecting means for detecting a brake operation amount, an operation speed detecting means for detecting a brake operation speed, and detecting a brake operation time Operation time detection means, and control for starting an assisting operation by the brake force assisting means when the brake operation amount is equal to or more than a predetermined amount, the brake operation speed is equal to or more than a predetermined speed, and the brake operation time is equal to or more than a predetermined time. Means.

Preferably, when the brake operation amount is equal to or more than a predetermined amount and the brake operation speed is equal to or more than a predetermined speed, the emergency determination means determines that it is necessary to assist the braking force. It also has

Preferably, when the brake operation amount is equal to or more than a predetermined amount and the brake operation time is equal to or more than a predetermined time, the emergency determination means determines that it is necessary to assist the braking force. It also has

Preferably, when the brake operation amount is a predetermined amount or more, the brake operation speed is a predetermined speed or more, and the brake operation time is a predetermined time or more,
The apparatus further includes emergency determination means for determining that it is necessary to assist the braking force in an emergency.

[0012] Preferably, the predetermined amount, the predetermined speed or the predetermined time is changed according to the vehicle speed.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

In the following, for convenience of explanation, the brake control by the booster at normal time is called "boost control", and the brake control of the emergency brake assist device for the booster at emergency is called "assist control". I will. [Apparatus Configuration] FIG. 1 is a block diagram of a vehicle braking apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the vehicle braking device 1 of the present embodiment includes a main booster 13 and a sub booster 14 connected in series. The main booster 13 and the sub booster 14 are provided between the brake pedal 11 and the master cylinder 16.

The main booster 13 has a diaphragm 13a urged leftward in the figure by a return spring in a shell, and a diaphragm chamber 13b partitioned by the diaphragm 13a has a vacuum pressure or a vacuum pressure in an intake manifold of the engine. The vacuum pressure from the vacuum pump is supplied via a check valve 19.

Similarly, the sub-booster 14 includes a diaphragm 14a urged leftward in the figure by a return spring in a shell, and an air chamber 17 is connected to a diaphragm chamber 14b partitioned by the diaphragm 14a. I have.

The air chamber 17 has a check valve 1
Vacuum pressure is supplied via the vacuum valve 9 and the vacuum valve 15, and atmospheric pressure is supplied via the atmospheric pressure valve 9. These vacuum valves 15
And the atmospheric pressure valve 9 are duty solenoid valves, and the opening of each valve 9, 15 is controlled by the control unit 1.
The duty is controlled by 0. As will be described later, the control unit 10 changes the assist magnification of the sub booster 14 to the main booster by controlling the opening of each valve. The control unit 10 includes a general central processing unit (CPU), a ROM for storing control programs and the like, and an R for storing vehicle speed, brake depression amount, and the like.
AM, clock timer, etc.

The brake pedal 11 and the master cylinder 16
Are connected by a rod 16a extending through the center of each of the diaphragms 13a and 14a provided in the main booster 13 and the sub-booster 14. The center of both diaphragms 13a and 14a is engaged with the rod 16a. Have been combined.

Therefore, the two diaphragm chambers 13b, 14b
Becomes negative pressure, the center of each of the diaphragm chambers 13b and 14b is displaced rightward in the drawing against the urging force of each return spring, and this displacement causes the assist pressure in addition to the pedaling pressure of the brake pedal 11 and the rod pressure. 16a.

The depressing force of the brake pedal is applied to the piston of the master cylinder 16 by multiplying the assist pressure of the main booster 13 and the assist pressure of the sub booster 14, and the assist pressure by the sub booster 14 is made variable. , The assist pressure as a whole is changed.

The disc brake device 20 comprises a brake disc 20a which is hydraulic and rotates together with wheels, and a caliper 2.
0b. The caliper 20b holds the brake pad, and the brake pad is pressed against the brake disc with a pressure corresponding to the brake fluid pressure supplied from the master cylinder to the cylinder through an oil passage, thereby generating a braking force on the wheel.

The illustrated disc brake device 20 is for a front wheel, and brake fluid pressure for a rear wheel brake device (not shown) is supplied from a hydraulic passage through a proportioning valve 22.

The control unit 10 includes a stroke sensor 1 for detecting an amount of depression of a brake pedal 11.
2, pedal depression amount detection signal pp, air chamber 17
The chamber pressure sensor signal pc from the pressure sensor 18 for detecting the internal pressure, the vehicle speed signal v from the vehicle speed sensor 21 for detecting the vehicle speed, and the accelerator depression amount detection signal from the accelerator stroke sensor 24 for detecting the depression amount of the accelerator pedal 23 a is entered. Further, the control unit 10 outputs a vacuum pressure control signal d1 and an atmospheric pressure control signal d2 for controlling the duty solenoid for the vacuum valve 15 and the atmospheric pressure valve 9.
Further, when the ignition switch 25 (IG switch) is turned on, the control unit 10 receives an ON signal thereof. As a sensor for detecting the amount of depression of the brake pedal, a pedal pressure sensor or the like may be applied in addition to the stroke sensor 12.

The control unit 10 determines that the pedal operation time tp (the pedal depression amount pp is a predetermined amount)
Then, the operation speed pv1 or the pedal return speed pv2 of the brake pedal is calculated based on the pedal depression amount detection signal pp and the pedal operation time tp. Then, the pedal depression amount pp, the pedal operation time tp, and the pedal operation speed pv1, pv2 become the predetermined amount pp1, pp2, the predetermined speed pv
10, pv20, the boost magnification k (assist amount) in the sub booster 14 based on the time that is longer than the predetermined time tp0 (the time when the pedal is released is reduced).
And a target pressure value in the air chamber 17 is set in order to obtain the boost magnification k, and the vacuum pressure control signal d1 and the atmospheric pressure control signal output from the target pressure value to the vacuum valve 15 and the atmospheric pressure valve 9 are set. The duty ratio of d2 is calculated, and the duty of the vacuum valve 15 and the atmospheric pressure valve 9 is controlled so that the pressure value in the air chamber 17 approaches the target pressure value. This duty control takes a form of feedback control that approaches the target pressure value using the vacuum pressure and the atmospheric pressure. Predetermined amount pp1, pp2, predetermined speed pv10,
The pv20 and the predetermined time tp0 are changed according to the vehicle speed v as shown in FIGS.

In addition to the apparatus using the pneumatic actuator of the present embodiment, a configuration using a hydraulic actuator may be adopted. In this case, a brake assist hydraulic valve may be interposed between the master cylinder and the proportioning valve instead of the vacuum valve, the atmospheric pressure valve, the sub booster, and the air chamber. [Control Process] Next, an assist control process by the vehicle braking device of the present embodiment will be described. <Assist Control Intervention Judgment Processing> FIG. 2 is a flowchart for explaining the assist control intervention judgment processing by the vehicle brake system of the present embodiment.

As shown in FIG. 2, when the process is started,
In step S2, the control unit 10
An ON signal is input from the switch 25 and the IG switch 2
It is determined whether 5 has changed from off to on. If the IG switch 25 has changed from off to on in step S2, the process proceeds to step S4. If the IG switch 25 has not changed from off to on, the process proceeds to step S6. In step S4, the flags F1 and F2 are reset. The flag F1 is a flag set to determine the start of the assist control, and the flag F2 is a flag set to determine whether the assist control has been performed at least once since the IG was turned on.

In step S6, the control unit 10 reads from the ROM the predetermined amounts pp1 and pp0, which are the threshold values of the pedal depression amount pp, and the predetermined time t, which is the threshold value of the pedal operation time tp.
Predetermined speeds pv10, pv20 which are thresholds of p0 and operation speeds pv1, pv2
And read.

In step S8, the pedal depression amount pp from the pedal stroke sensor 12 and the chamber pressure pc from the pressure sensor 18 are detected. In step S10, it is determined whether or not the flag F1 is set (F1 =
1? ). If the flag F1 has not been set in step S10 (NO in step S10), step S12
If the flag F1 is set (YES in step S10), the process proceeds to step S70 described later.

In step S12, the pedal depression amount pp
Is greater than zero, that is, whether the brake pedal is depressed. If the brake pedal is depressed in step S12 (pp> 0), the process proceeds to step S14,
If the brake pedal is not depressed (pp = 0), the pedal operation time tp is reset in step S32, and the process returns to step S2 to repeat the program again.

In step S14, a pedal operation speed pv1 of the brake pedal is calculated. This pedal operation speed pv1
Is calculated by dividing the difference between the current pedal depression amount and the previous depression amount (one cycle before the sampling time) by the sampling time (control cycle period) ΔT. Note that the pedal operation speed pv1 may be calculated by interpolation using the previous data.

In step S16, the pedal operation speed pv1
Is greater than or equal to a predetermined amount pv10. Step S1
If the pedal operation speed pv1 exceeds the predetermined amount pv10 in step 6 (YES in step S16), the process proceeds to step S18, and if the pedal operation speed pv1 is equal to or lower than the predetermined amount pv10 (step S6).
(NO at 16) After resetting the pedal operation time tp at step S32, the process returns to step S2 and repeats this program again.

In step S18, the pedal depression amount pp
Is greater than or equal to a predetermined amount pp0. Step S1
If the pedal depression amount pp exceeds the predetermined amount pp0 in step 8 (YES in step S18), the process proceeds to step S20, and if the pedal depression amount pp is equal to or smaller than the predetermined amount pp0 (step S18).
(NO at 18) Step S32 After resetting the pedal operation time tp, the process returns to Step S2 and repeats this program again.

In step S20, it is determined whether or not the flag F2 has been set, that is, the pedal depression amount pp is less than or equal to the predetermined amount pp0 until the previous sampling, and this is the first time that the pedal depression amount pp has exceeded the predetermined amount pp0. Is determined. If flag F2 is not set in step S20 (YES in step S20), the process proceeds to step S22, and if flag F2 is set (NO in step S20), the process proceeds to step S26.

In step S22, a flag F2 is set. In step S24, the pedal operation time tp is set to one cycle ΔT
(Tp = ΔT). On the other hand, in step S26, the pedal operation time tp is added by ΔT for one cycle (tp = tp +
ΔT).

In step S28, it is determined whether or not the pedal operation time tp exceeds a predetermined time tp0. Step S2
If the pedal operation time tp exceeds the predetermined time tp0 in step 8 (YES in step S28), the process proceeds to step S30. If the pedal operation time tp is equal to or shorter than the predetermined time tp0 in step S28, the process returns to step S2 to repeat the program again. .

In step S30, the flag F1 is set to indicate that the assist control is started, and then the process returns to step S2 to repeat the program again. <Assist Control Process> FIG. 3 is a flowchart illustrating an assist control process by the vehicle braking device of the present embodiment.

As shown in FIG. 3, when the process is started,
In step S40, the control unit 10 determines whether or not the flag F1 is set, that is, whether or not the assist control has been started. If the flag F1 is set in step S40 (F1 = 1), the process proceeds to step S42, and if the flag F1 is not set (F1 = 0), the process proceeds to step S44.

In step S42, the boost multiplier k by the sub-booster 14 is set to the emergency multiplier 2. On the other hand, in step S44, the boost magnification k by the sub booster 14 is set to the magnification 1 in the normal boost control. The boost magnification k can be set to a large value according to the running state of the vehicle or the driver's depression of the brake pedal, for example, when the vehicle speed v is high and the pedal operation speed pv1 is high. As a result, the braking performance can be further improved when the deceleration request is large. Further, the boost magnification may be controlled so that braking by full braking or a predetermined braking force generation pattern is achieved.

In step S46, the target chamber pressure pt corresponding to the boost magnification k is determined from the map showing the relationship between the boost magnification k and the target chamber pressure pt shown in FIG. In step S48, a chamber pressure deviation Δp is calculated. The chamber pressure deviation Δp is calculated by subtracting the boost pressure pc from the target chamber pressure pt (Δp = p
t-pc). In step S50, it is determined whether the chamber pressure deviation Δp is equal to or less than the pressure control threshold α. Step S
If the chamber pressure deviation Δp is equal to or less than the pressure control threshold α at 50 (YES in step S50), the process proceeds to step S52. If the chamber pressure deviation Δp exceeds the pressure control threshold α (NO at step S50), the process proceeds to step S60. .

In step S52, the chamber pressure deviation Δp
Is smaller than or equal to the pressure control threshold value -α. If the chamber pressure deviation Δp is equal to or less than the pressure control threshold value −α in step S52 (YES in step S52), step S
Proceeding to 54, if the chamber pressure deviation Δp exceeds the pressure control threshold value -α (NO in step S52), step S64
Proceed to. In steps S50 and S52, a dead zone from the pressure control threshold value α to −α is set in the chamber pressure deviation Δp, and it is determined whether Δp> α, Δp <−α, and −α ≦ Δp ≦ α. doing.

In steps S54 and S56, it is determined that the chamber pressure deviation Δp satisfies -α ≦ Δp ≦ α, which means that the boost pressure pc in the air chamber 17 is within the target range. 15 and the atmospheric pressure valve 9 are both set to be closed. In step S58, the vacuum pressure control signal d1 for setting the duty ratio to 0% is set.
And an atmospheric pressure control signal d2 are output to close both valves to maintain the pressure in the air chamber 17.

In step S60, since it is determined that the chamber pressure deviation Δp is Δp> α, it means that the boost pressure pc in the air chamber 17 is too high, and the vacuum valve 15 is closed and the air chamber 17 is closed. In step S62, a duty ratio corresponding to the chamber pressure deviation Δp is determined from a map representing the relationship between the chamber pressure deviation Δp and the duty ratio shown in FIG. At S58, an atmospheric pressure control signal d2 corresponding to the duty ratio is output, and a vacuum pressure control signal d1 for closing the vacuum valve 15 is set to 0%.

Further, in step S64, since it is determined that the chamber pressure deviation Δp is Δp <−α, it means that the boost pressure pc in the air chamber 17 is too low. It is set so that only the vacuum pressure is introduced into the chamber 17, and in step S66,
From the map showing the relationship between the chamber pressure deviation Δp and the duty ratio shown in FIG. 116, the duty ratio according to the chamber pressure deviation Δp is determined, and in step S58, the vacuum pressure control signal d1 corresponding to this duty ratio is output and And outputs an atmospheric pressure control signal d2 for closing the atmospheric pressure valve 9 at a duty ratio of 0%.

According to the embodiment described above, the pedal operation speed pv1 is set to the predetermined speed p as the assist control start condition.
The assist control is started when the pedal depression time tp is greater than v10, the pedal depression amount pp is greater than the predetermined amount pp0, and the pedal depression time tp is greater than the predetermined time tp0.

Accordingly, in addition to determining the start of the assist control based on the operation speed of the brake pedal (see FIG. 17), the start of the assist control is determined in consideration of the amount of depression of the pedal and the duration of the depression. The assist control is not executed when the driver steps on the vehicle so that the rise is quicker (see FIG. 18) or when the pumping brake is performed (see FIG. 19). Further, since the brake is applied more than necessary, it is possible to prevent the driver from being surprised and the following vehicle from approaching suddenly.

If the pedal operation speed pv1, the pedal depression amount pp, and the pedal depression time tp are a combination of three factors, for example, the pedal operation speed pv1 becomes the predetermined speed pv1.
Assist control is started so that the assist control is started when the pedal depression amount pp is greater than the predetermined amount pp0 and when the pedal depression amount pp is greater than the predetermined amount pp0 and the pedal depression time tp is greater than the predetermined time tp0. Conditions may be set.

<Assist Control End Judgment Processing> FIG. 4 is a flowchart for explaining the assist control end judgment processing by the vehicle brake system of the present embodiment.

As shown in FIG. 4, step S shown in FIG.
After the process at 58, the process proceeds to step S70. In step S70, the control unit 10 calculates the return speed pv2 of the brake pedal. This pedal return speed pv2 is calculated by dividing the difference between the previous stepping amount (one cycle before the sampling time) and the current pedaling amount by the sampling time (control cycle period) ΔT. Note that the pedal return speed pv2 may be calculated by interpolation using the previous data.

In step S72, the vehicle speed v shown in FIG.
The predetermined value pp1 is corrected according to the vehicle speed v from a map representing the relationship between the threshold value and the predetermined amount pp1 as the threshold value of the pedal depression amount pp. Note that the predetermined amount pp1 is the pedal return speed pv2 shown in FIG.
The correction may be made in accordance with the pedal return speed pv2 from a map representing the relationship between and the predetermined amount pp1.

In step S74, the pedal return speed pv2
Is smaller than a predetermined amount pv20. Step S
If the pedal return speed pv2 is smaller than the predetermined amount pv20 at 74 (YES at step S74), the process proceeds to step S76.
If the pedal return speed pv2 is equal to or greater than the predetermined amount pv20 (NO in step S74), the process proceeds to step S80.

In step S76, the pedal return speed pv2
Is smaller than the predetermined amount pv20, it is determined that the driver has slowly returned the brake pedal, and it is determined whether the pedal depression amount pp is smaller than the predetermined amount pp1. If the pedal depression amount pp is smaller than the predetermined amount pp1 in step S76 (YES in step S76), the process proceeds to step S78. If the pedal depression amount pp is equal to or larger than the predetermined amount pp1 (NO in step S76), step S40 shown in FIG. And the assist control is continued.

In step S78, the assist control is terminated, and the flag F1 is reset (F1 = 0) in order to start the normal boost control by the main booster 13.

In step S80, the pedal return speed pv2
Is larger than the predetermined amount pv20, it is determined that the driver has returned the brake pedal suddenly, and the pedal depression amount pp
Is smaller than a predetermined amount pp1. Step S
If the pedal depression amount pp is smaller than the predetermined amount pp1 at 80 (YES in step S80), the process proceeds to step S82,
If the pedal depression amount pp is equal to or more than the predetermined amount pp1 (NO in step S80), the process returns to step S40 shown in FIG. 3 to continue the assist control.

In step S82, the pedal depression amount pp
Is greater than zero, that is, whether the brake pedal is depressed. If the brake pedal is depressed in step S12 (pp> 0), step S12 shown in FIG.
Returning to step 40, the assist control is continued, and if the brake pedal is not depressed (pp = 0), the process proceeds to step S78, in which the flag F1 is set to end the assist control and start the normal boost control. Reset (F1 = 0).

In the above steps S74 → S80, for example, the driver is surprised by the assist control and suddenly returns the brake pedal. However, when the pedal depression amount is large, the assist control is continued, and when the pedal depression amount is small. After determining whether the brake pedal has been completely returned,
If the brake pedal is still depressed, the assist control is continued, and if the brake pedal is completely released, the assist control is ended.

According to the present embodiment described above, the pedal depression amount pp becomes smaller than the predetermined amount pp1 in a slow return operation in which the pedal return speed pv2 of the brake pedal is smaller than the predetermined speed pv20 as a condition for judging the end of the assist control. When the assist control is released (see FIG. 20), the pedal return speed pv2 of the brake pedal becomes the predetermined speed p.
Pedal depression amount pp for sudden return operation larger than v20
Will not be released until is zero (see FIG. 21).

Therefore, even if the driver is surprised by the assist control due to the emergency deceleration behavior and suddenly returns the brake pedal, the assist control is continued when the pedal depression amount is large, and conversely, when the pedal depression amount is small. Determines whether or not the brake pedal is completely returned as the condition for ending the assist control, so that the assist control is reliably executed in a situation where the assist control is necessary. <Another Embodiment> In step S82 described above, it is determined whether to continue the assist control by determining whether the accelerator pedal 23 is depressed other than the brake pedal depression amount pp (accelerator pedal depression amount> 0?). Alternatively, whether the stepping amount is equal to or more than a predetermined amount, or whether the idle switch has been switched from on to off, or the like may be used as the determination material. <Modification 1> Next, with reference to FIG. 5, a modification 1 of the assist control end determination processing of the present embodiment will be described.

FIG. 5 is a flowchart illustrating a first modification of the assist control end determination process according to the present embodiment.

As shown in FIG. 5, step S74 of FIG.
If the determination is NO, the control unit 10 determines in step S90 that the pedal depression amount pp is equal to the predetermined amount pp.
Determine whether it is less than 1. If the pedal depression amount pp is smaller than the predetermined amount pp1 in step S90 (YES in step S90), the process proceeds to step S92, and if the pedal depression amount pp is equal to or larger than the predetermined amount pp1 (N in step S90).
O), the process returns to step S40 shown in FIG. 3 to continue the assist control.

In step S92, the counter t is incremented (t = t + 1). In step S94, it is determined whether the counter t has exceeded a predetermined value t0. Step S
If the counter t has exceeded the predetermined value t0 at 94 (YES at step S94), the routine proceeds to step S98, where the flag F1 is set.
And the counter t are reset to end the assist control.
If the counter t does not exceed the predetermined value t0 in step S94 (NO in step S94), the process proceeds to step S96 to determine whether the pedal depression amount pp is zero, that is, whether the brake pedal is depressed. If the brake pedal is depressed in step S96 (pp> 0), the process returns to step S40 shown in FIG. 3 to continue the assist control, and if the brake pedal is not depressed (pp = 0), step S98 Then, the assist control is terminated.

In this modification, since the assist control end condition is delayed by a predetermined time t0 after the assist control end condition (pp <pp1) is satisfied, the assist control may be suddenly canceled. In other words, even if the driver is surprised by the assist control and suddenly returns the brake pedal, the assist control is surely executed in a necessary situation. <Modification 2> Next, a modification 2 of the assist control end determination processing of the present embodiment will be described with reference to FIG.

FIG. 6 is a flowchart illustrating a second modification of the assist control end determination process according to the present embodiment.

As shown in FIG. 6, step S74 in FIG.
If the determination in step NO is NO, in step S100, the control unit 10 determines that the pedal depression amount pp is a predetermined amount.
It is determined whether it is smaller than pp1. If the pedal depression amount pp is smaller than the predetermined amount pp1 in step S100 (YES in step S100), the process proceeds to step S102, and if the pedal depression amount pp is equal to or more than the predetermined amount pp1 (step S100).
(NO at 100), the process returns to step S40 shown in FIG. 3 to continue the assist control.

In step S102, the counter t is incremented (t = t + 1). In step S104, the magnification k1 of the boost magnification k corresponding to the counter t is determined from the map showing the relationship between the counter t and the magnification k1 shown in FIG. In step S106, it is determined whether the magnification k1 is 0.5. If the magnification k1 is 0.5 in step S106 (YES in step S106), the process proceeds to step S110 to reset the flag F1 and the counter t and end the assist control. If the magnification k1 exceeds 0.5 in step S106 (NO in step S106), step S10
Proceeding to 8, it is determined whether the pedal depression amount pp is zero, that is, whether or not the brake pedal is depressed. Step S10
If the brake pedal is depressed in step 8 (pp> 0), the process returns to step S40 shown in FIG. 3 to continue the assist control, and if the brake pedal is not depressed (pp =
0) Proceed to step S110 to end the assist control. Here, the magnification k of the boost magnification k in step S104
The value of 1 is set between 0.5 and 1, and the value of boost factor k is 1
This is a value set between ~ 2. Therefore, this magnification k1
Is 0.5, the boost magnification k is set between 0.5 and 1, that is, a state in which normal boost control is executed. Further, the magnification k1 set in step S104 is multiplied by the boost magnification k set in steps S42 and S44 in FIG. 3 (k = k1 × k).

In this modified example, the boost magnification k is gradually reduced in accordance with the elapsed time from when the assist control end condition (pp <pp1) is satisfied, and the assist amount during the assist control is gradually reduced. Assist control is not suddenly released, so even if the driver is surprised at the assist control and suddenly returns the brake pedal, it is reliably executed in the situation where the assist control is required Will be.

The present invention can be applied to a modification or modification of the above embodiment without departing from the spirit thereof.

[0068]

As described above, according to the present invention, when the brake operation amount is equal to or more than the predetermined amount and the brake operation speed is equal to or more than the predetermined speed, the assisting operation of the braking force is started. Intervention can be reduced.

Further, when the brake operation amount is equal to or more than the predetermined amount and the brake operation time is equal to or more than the predetermined time, the assisting operation of the braking force is started, so that unnecessary assist intervention can be suppressed.

When the brake operation amount is equal to or more than a predetermined amount, the brake operation speed is equal to or more than a predetermined speed, and the brake operation time is equal to or more than a predetermined time, the assisting operation of the braking force is started. be able to.

Preferably, when the brake operation amount is equal to or more than a predetermined amount and the brake operation speed is equal to or more than the predetermined speed, it is determined that the emergency is required to assist the braking force. Can be performed.

Preferably, when the brake operation amount is equal to or more than a predetermined amount and the brake operation time is equal to or more than a predetermined time, it is determined that the emergency is necessary to assist the braking force. Can be performed.

Preferably, when the brake operation amount is equal to or more than a predetermined amount, the brake operation speed is equal to or more than a predetermined speed, and the brake operation time is equal to or more than a predetermined time, it is determined that it is necessary to assist the braking force in an emergency. Therefore, during an emergency, assist intervention can be reliably performed.

Preferably, the predetermined amount, the predetermined speed or the predetermined time is changed according to the vehicle speed, so that it is possible to make an assist intervention determination according to the running state of the vehicle.

[0075]

[Brief description of the drawings]

FIG. 1 is a block diagram of a vehicle braking device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an assist control intervention determination process performed by the vehicle braking device according to the embodiment.

FIG. 3 is a flowchart illustrating an assist control process by the vehicle braking device according to the embodiment.

FIG. 4 is a flowchart illustrating an assist control end determination process performed by the vehicle braking device according to the embodiment.

FIG. 5 is a flowchart illustrating a first modification of the assist control end determination process according to the embodiment;

FIG. 6 is a flowchart illustrating a second modification of the assist control end determination process according to the embodiment.

FIG. 7 is a map showing a relationship between a vehicle speed v and a predetermined speed pv10 as a threshold value of a pedal operation speed pv.

FIG. 8 is a map showing a relationship between a vehicle speed v and a predetermined amount pp0 as a threshold value of a pedal depression amount pp.

FIG. 9 is a map showing a relationship between a vehicle speed v and a predetermined time tp0 as a threshold value of a pedal operation time tp.

FIG. 10 is a map showing a relationship between a vehicle speed v and a predetermined speed pv20 as a threshold value of a pedal return speed pv2.

FIG. 11 is a map showing a relationship between a vehicle speed v and a predetermined amount pp1 as a threshold value of the pedal operation amount pp.

FIG. 12 is a map showing a relationship between a pedal return speed pv2 and a predetermined amount pp1 as a threshold value of the pedal operation amount pp.

FIG. 13 is a map showing a relationship between an elapsed time t from when an assist control end condition is satisfied and a magnification k1 multiplied by a boost magnification k.

FIG. 14 is a map showing a relationship between a boost magnification k and a target chamber pressure pt.

FIG. 15 is a map showing a relationship between a chamber pressure deviation Δp and a duty ratio of an atmospheric pressure valve.

FIG. 16 is a map showing a relationship between a chamber pressure deviation Δp and a duty ratio of a vacuum valve.

FIG. 17 is a diagram illustrating an operation at the time of assist control start determination.

FIG. 18 is a diagram illustrating an operation at the time of starting assist control.

FIG. 19 is a diagram for explaining the operation at the time of starting the assist control.

FIG. 20 is a diagram illustrating an operation at the time of determining the end of assist control.

FIG. 21 is a diagram illustrating an operation at the time of determining the end of assist control.

[Explanation of symbols]

 9 ... Atmospheric pressure valve 10 ... Control unit 11 ... Brake pedal 12 ... Brake pedal stroke sensor 13 ... Main booster 14 ... Sub booster 15 ... Vacuum valve 16 ... Master cylinder 17 ... Air chamber 18 ... Pressure sensor 19 ... Check valve 20 ... Disc brake Device 21: Vehicle speed sensor 22: Proportioning valve 23: Accelerator pedal 24: Accelerator pedal stroke sensor

Claims (7)

[Claims] A brake force assisting means for assisting a braking force generated in response to a brake operation; an operation amount detecting means for detecting a brake operation amount; an operation speed detecting means for detecting a brake operation speed; A braking device for a vehicle, comprising: control means for starting an assisting operation by the braking force assisting means when the amount is equal to or more than a predetermined amount and the brake operation speed is equal to or more than the predetermined speed. 2. A brake force assisting means for assisting a braking force generated in response to a brake operation; an operation amount detecting means for detecting a brake operation amount; an operation time detecting means for detecting a brake operation time; A braking device for a vehicle, comprising: control means for starting an assisting operation by the braking force assisting means when the amount is equal to or more than a predetermined amount and the brake operation time is equal to or more than a predetermined time. 3. A brake force assisting means for assisting a braking force generated in response to a brake operation, an operation amount detecting means for detecting a brake operation amount, an operation speed detecting means for detecting a brake operation speed, and a brake operation time Operating time detecting means for detecting, when the brake operation amount is a predetermined amount or more and the brake operating speed is a predetermined speed or more and the brake operation time is a predetermined time or more, the assisting operation by the brake force assisting means A braking device for a vehicle, comprising: control means for starting the vehicle. 4. An emergency judging means for judging an emergency when it is necessary to assist the braking force when the brake operation amount is equal to or more than a predetermined amount and the brake operation speed is equal to or more than a predetermined speed. The vehicle braking device according to claim 1, wherein: 5. An emergency judging means for judging an emergency when it is necessary to assist the braking force when the brake operation amount is a predetermined amount or more and the brake operation time is a predetermined time or more. 3. The vehicle braking device according to claim 2, wherein: 6. An emergency when it is necessary to assist the braking force when the brake operation amount is a predetermined amount or more, the brake operation speed is a predetermined speed or more, and the brake operation time is a predetermined time or more. The braking device for a vehicle according to claim 3, further comprising an emergency determination unit for determining. 7. The vehicle according to claim 1, wherein the predetermined amount, the predetermined speed or the predetermined time is changed according to a vehicle speed.
The vehicle braking device according to claim 6.