JP2704772B2 - Vehicle brake hydraulic control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of Industrial Application The present invention relates to an electric actuation type actuator for outputting a braking oil pressure which increases as an applied electric energy increases. The present invention relates to a vehicle brake hydraulic pressure control method for setting an electric quantity in accordance with a braking operation amount.

(2) Prior Art Conventionally, such a vehicle brake hydraulic pressure control method is known, for example, from JP-A-62-258844.

(3) Problems to be Solved by the Invention By the way, in the above conventional device, the amount of electricity applied to the electrically actuated actuator is made to correspond to the amount of braking operation in proportion to the amount of braking operation. The braking hydraulic pressure that becomes proportionally large is output from the actuator.

However, in the above-described conventional apparatus, the braking oil pressure fluctuates as the amount of applied electricity changes due to body vibration or the like, and the braking oil pressure acting on the brake device fluctuates unnecessarily, making stable control difficult. Becomes

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a vehicle brake hydraulic pressure control method capable of performing stable control without following a change in applied hydraulic pressure due to a change in applied electric energy due to vehicle body vibration or the like.

B. Configuration of the Invention (1) Means for Solving the Problems According to the first feature of the present invention, an electrically actuated actuator that outputs a braking oil pressure that increases as the amount of applied electricity increases. In the brake hydraulic pressure control method for a vehicle, wherein the applied amount of electricity is set in accordance with the amount of braking operation, when the amount of decrease in the amount of braking operation is equal to or less than a predetermined amount of reduction while the amount of braking operation is greater than or equal to a predetermined value, Is kept constant, and when the braking operation amount decreases beyond a predetermined reduction amount, the applied electric amount is allowed to decrease.

According to the second feature of the present invention, the predetermined decrease amount is largely changed as the braking operation amount increases.

Further, according to the third aspect of the present invention, the predetermined decrease amount is largely changed as the vehicle speed increases.

(2) Operation According to the first feature, when the amount of decrease in the amount of braking operation is equal to or less than the predetermined value, it is possible to keep the braking hydraulic pressure constant as a change unrelated to the driver's intention.

According to the second feature, when a large braking force is applied, a change in responsiveness to a change in the braking force can be suppressed by setting the predetermined decrease amount to be larger.

Further, according to the third feature, when the vehicle body speed is high, the required braking force increases in accordance with the increase in the inertial force. Therefore, it is possible to suppress the change in the responsiveness by setting the predetermined reduction amount to be larger. .

(3) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

First, in FIG. 1 showing a first embodiment of the present invention, a left front wheel brake device _BFL and a right front wheel brake device _BFR are mounted on a left front wheel and a right front wheel of a vehicle, respectively, and a left rear wheel and a right rear wheel are mounted. The left rear wheel brake device _BRL and the right rear wheel brake device _BRR are mounted on the wheels. On the other hand, a reaction force generating means 2 for exerting a spring force opposing the depression force of the brake pedal 1 is connected to the brake pedal 1 via a depression force sensor 3 for detecting a braking operation amount. The hydraulic pressure from the hydraulic supply 5 controlled by the electric actuator 4 in accordance with the braking operation amount detected by the pedaling force sensor 3 is applied to each front wheel brake device.
B _FL , B _FR and brake devices B _RL , B _RR for each rear wheel. The respective front wheel brake device B _FL, normally open electromagnetic inlet valve 6 _FL as antilock control valve provided corresponding individually to B _FR, 6 _FR and the normally closed electromagnetic spill valve 7 _FL, 7 _FR, and both the rear wheel brake device B _RL, normally open electromagnetic inlet valve 6 _R and normally closed each braking device by the electromagnetic spill valve 7 _R B _FL as antilock control valve provided in common to B _RR, B _FR , B _RL ,
It can be carried out antilock control braking oil B _RR holding or reduced to.

The hydraulic supply source 5 includes a hydraulic pump 9 for pumping hydraulic oil from a reservoir 8, an accumulator 10 connected to the hydraulic pump 9, and a pressure switch 11 for controlling the operation of the hydraulic pump 9.

The electrically actuated actuator 4 includes a housing 13 having a cylinder hole 12 whose one end in the axial direction is closed.
A spool 14, which is slidably fitted on the spool 14, a reaction force piston 15 which is slidably fitted into the cylinder hole 12 while abutting on the spool 14, and And an electric operating portion 16 attached to the other axial side surface of the housing 13 to exert a driving force for pressing.

An output chamber 17 is defined between one end of the spool 14 and one end wall of the cylinder hole 12, and a spring 18 for urging the spool 14 to the other axial side is housed in the output chamber 17.

An annular output pressure action chamber 19 facing the front surface of the reaction force piston 15 is defined by the inner surface of the cylinder hole 12, the spool 14, and the reaction force piston 15. Moreover, the spool 14 has an output chamber
A communication path 20 leading to 17 is bored over the entire length in the axial direction,
The reaction force piston 15 is provided with a communication hole 21 for communicating the communication passage 20 with the output pressure action chamber 19. Thus, the hydraulic pressure of the output pressure action chamber 19 communicating with the output chamber 17 causes an oil pressure to act on the reaction force piston 15 in the other axial direction (the right side in the drawing), and the spool 14 applies the spring force of the spring 18. As a result, it moves while following the reaction force piston 15.

On the other hand, the electric operating section 16 has a built-in linear solenoid (not shown) that exerts a thrust corresponding to the amount of applied electricity, and a driving rod 22 driven by the linear solenoid is integrated with the reaction force piston 15. It is coaxially abutted on the provided piston rod 15a. Therefore, the thrust of the electric operating portion 16 acts on the spool 14 toward one side in the axial direction, and the hydraulic pressure of the output pressure working chamber 19 acts on the other side in the axial direction, thereby balancing the thrust and the hydraulic pressure. As a result, the spool 14 moves in the axial direction.

The housing 13 has an output port 23 that is always in communication with the output chamber 17, a release port 24 that is in communication with the reservoir 8, and an input port 25 that is in communication with the hydraulic pressure source 5, and is spaced apart from one side in the axial direction. Drilled in order.

On the other hand, the spool 14 has an input port 25 and a communication passage 20.
There is provided a first valve hole 26 capable of communicating between the two, and a second valve hole 27 capable of communicating between the release port 24 and the communication passage 20.
The arrangement of 6, 27 is such that when the spool 14 moves to one side in the axial direction, the first valve hole 26 communicates between the input port 25 and the communication passage 20, whereas the spool 14 moves to the other side in the axial direction. In the moving state, the second valve hole 27 is set to be in a state of communicating between the release port 24 and the communication passage 20.

The amount of electricity applied to the electric operating unit 16 is controlled by the control unit 28. The control unit 28 controls the electric operating unit 16 in accordance with the braking operation amount detected by the pedaling force sensor 3.
Is configured to control the thrust.

According to such an electrically actuated actuator 4, the output oil pressure of the oil pressure supply source 5 is controlled according to the amount of electricity input to the electric actuation unit 16 and output from the output port 23.

Each of the brake devices B _FL , B _FR , B _RL , and B _RR is a brake piston which is slidably fitted in the cylinder body 30.
31 and a cylinder body 30 and a braking piston, respectively.
The braking force is exerted by the movement of the braking piston 31 according to the hydraulic pressure acting on the braking hydraulic chamber 32 defined between 31.

The normally open solenoid valves 6 _FL and 6 _FR are brake devices for the front wheels.
B _FL, and the brake hydraulic pressure chamber 32 in the B _FR, are respectively interposed between the output port 23 of the actuator 4, normally closed electromagnetic spill valve 7 _FL, 7 _FR is front wheel brake device B _FL, braking in B _FR It is interposed between the hydraulic chamber 32 and the reservoir 8, respectively. The normally open solenoid valve 6 _R is a brake device for both rear wheels.
B _RL, is interposed between the output port 23 of the braking hydraulic pressure chambers 32 and the actuator 4 of the B _RR, the normally closed electromagnetic spill valve 7 _R, both rear wheel brake device B _RL, the braking oil pressure chamber B _RR It is interposed between the reservoir 32 and the reservoir 8.

These normally open electromagnetic inlet valve 6 _FL, 6 _FR, 6 _R and the normally closed electromagnetic spill valve 7 _FL, 7 _FR, 7 excitation and demagnetization switching _R control unit 28
Is controlled by

Next, a configuration for controlling the electric operating section 16 of the actuator 4 in the control means 28 will be described with reference to FIG.

The control unit 28 includes an input unit 35 to which an electric signal from the treading force sensor 3, that is, an operation amount-corresponding electric amount F _{OUT (n)} corresponding to the braking operation amount, and an electric operation unit of the actuator 4.
And an output section 36 for outputting an applied electric quantity F _{IN (n + 1)} corresponding to an electric quantity to be given to the motor 16, that is, an output braking oil pressure of the actuator 4. The output section 36 is controlled according to a braking state and a running state of the vehicle. The electric quantity F _{IN (n + 1)} is supplied from the control means 28 to the electric operation section 16 of the actuator 4.

The manipulated variable corresponding electric quantity F _{OUT (n)} input to the input unit 35 is
It is input to the first calculation unit 37. Follows when the The first operation unit 37 is operation by the following equation (1), also F _OUT.0 than when the operation amount corresponding electrical quantity F _{OUT (n)} is less than the switching換設value F _OUT.0 (2) is performed to output a calculated electric quantity _{F'OUT (n)} .

_{F 'OUT (n) = F} OUT (n) ...... (1) (F OUT (n) <F OUT.0) F' OUT (n) = F OUT (n) + θ × (F OUT (n) - _{F OUT.0) ...... (2) (} F OUT (n) ≧ F OUT.0) That is, as from the first operation unit 37 shown by the solid line in FIG. 3, a boundary switching換設value F _OUT.0 And the manipulated variable corresponding electric quantity F
Two types of calculated electric quantities F 'having different rates of change with respect to _{OUT (n)
OUT (n)} , and when F _{OUT (n)} <F _OUT.0 , the electric quantity F ′ _{OUT (n)} having a large change rate is
When F _{OUT (n)} ≧ F _OUT.0 , the electric quantity F ′ _{OUT (n)} having a small change rate is output from the first calculation unit 37.

Incidentally, the switching set value F _OUT.0 is input from the manipulated _variable setting unit 38 to the first arithmetic unit 37, and the manipulated _variable setting unit 38 detects the vehicle speed V detected by the vehicle speed detection unit 39. _The switching set value F _OUT.0 is set according to _R as shown in FIG. That switching換設value F _OUT.0 is set to be larger as the vehicle speed V _R is increased.

Moreover the operation amount setting section 38 as a wheel is likely to cause locking, anti-lock control valve i.e. normally open electromagnetic inlet valve 6 _FL, 6 _FR, 6 _R and the normally closed electromagnetic spill valve 7 _FL, 7 _FR , when a signal indicating an anti-lock control state from the anti-lock control unit 40 for allowing operating the 7 _R is input, regardless of the vehicle speed V _R, the signal indicating the anti-lock control state from the anti-lock control unit 40 The switching set value F _OUT.0 at the time of input is retained, so that when F ′ _{OUT (n)} <F _OUT.0 at the start of the antilock control, , The operation electric quantity F ' _{OUT (n)} output from the first operation unit 37 is as shown by the chain line in FIG.

The output signal of the first arithmetic unit 37 is provided to one of the individual contacts 41a of the changeover switch 41. The changeover switch 41 has a pair of individual contacts 41a and 41b and a common contact 41c, and the other individual contact 41b is connected to the zero setting unit 42. In the zero setting section 42, _{F'OUT (n)} is set to zero ( _{F'OUT (n)} = 0).

The changeover switch 41 changes the switching mode according to the output of the comparator 43.When the output of the comparator 43 is at a high level, the individual contact 41a is connected to the common contact 41c.
When the output of the comparator 43 is at a low level, the individual contact 41b is brought into conduction with the common contact 41c. Thus, the manipulated variable corresponding electric quantity F _{OUT (n)} is input to the non-inverting input terminal of the comparator 43 from the input unit 35, and the set electric quantity F _I is input to the inverting input terminal from the dead zone contact bottom 44. You. The dead zone setting unit 44 is designed to avoid the generation of the braking oil pressure due to the input of the operation amount corresponding electric amount F _{OUT (n)} due to noise such as vehicle body vibration.
The maximum manipulated variable corresponding electric quantity F that can be generated by the noise
Is obtained by setting _{OUT (n) is} as set electric quantity F _I. Therefore, from the common contact 41c of the changeover switch 41, when the manipulated variable corresponding electric quantity F _{OUT (n)} exceeds the set electric quantity F _I , the first
When the calculated electric quantity F ′ _{OUT (n)} from the calculating section 37 and the manipulated variable corresponding electric quantity F _{OUT (n)} are equal to or smaller than the set electric quantity F _I , a zero electric quantity from the zero-contact bottom 42 is output. Will be done.

The common contact 41c of the changeover switch 41 is connected to the changeover switch 4
5 is connected to the individual contact 45b. The changeover switch 45 has a pair of individual contacts 45a and 45b and a common contact 45c. vessel
When the output of 46 is at a low level, the individual contact 45b is conducted to the common contact 45c. The common contact 45c of the changeover switch 45 is connected to the individual contact 47b of the changeover switch 47.
The changeover switch 47 has a pair of individual contacts 47a, 47b and a common contact 47c.When the output of the OR gate 48 is at a high level, the individual contact 47a is made conductive to the common contact 47c, and the OR gate 48 is turned on. When the output is at a low level, the individual contact 47b is made conductive to the common contact 47c.

The common contact 47c of the changeover switch 47 is connected to the output unit 36 and to the first holding unit 49. This first
The holding unit 49 includes an applied electric quantity F output from the output unit 36.
_{IN (n + 1)} is held only once in the control cycle, and the previous applied electric quantity F _{IN (n)} is output for the current control cycle.

A second operation unit 50 is connected to the individual contact 45a of the changeover switch 45. In the second operation unit 50, (F _{IN (n)} + ΔF
_IMAX ) is performed. In this calculation, F
_{IN (n)} is input from the first holding unit 49 to the second calculation unit 50, and ΔF
_IMAX is the maximum increase in the amount of applied electric energy, and the increase rate setting section
51 is input to the second arithmetic unit 50. That is, the increase ratio setting unit 51 sets the maximum increase amount ΔF _IMAX so as to limit the increase ratio of the applied electric amount when the manipulated variable corresponding electric amount F _{OUT (n)} is increasing to such an extent that the driver does not feel uncomfortable. is for setting a maximum increment [Delta] F _IMAX is determined based on the following first equation (3) using vehicle speed V _R from the vehicle speed detection unit 39.

ΔF _IMAX = ΔF _IMAX.0 × (K ₁ × V _R ) (3) where ΔF _IMAX.0 is a reference value and K ₁ is a coefficient.
According to the third (3), the maximum increment [Delta] F _IMAX will increase as the vehicle speed V _R is increased.

The maximum increase ΔF _IMAX obtained by the increase ratio setting section 51
Is input to the inverting input terminal of the comparator 46. On the other hand, a non-inverting input terminal of the comparator 46 is connected to an increasing speed calculating section 52. In the increase speed calculating section 52, an operation of subtracting the electric quantity F _{IN (n)} held by the first holding section 49 from the calculated electric quantity F ′ _{OUT (n)} obtained by the first calculating section 37 is executed. As a result, the amount of increase in the amount of braking operation per unit time can be obtained. Therefore, when the increasing speed of the braking operation amount exceeds the maximum increasing amount ΔF _IMAX , the comparator 46 outputs a high-level signal to make the individual contact 45a of the changeover switch 45 conductive to the common contact 45c, thereby increasing the braking operation amount. When the speed is less than the maximum increase ΔF _IMAX, a low-level signal is output and the changeover switch 45
Of the individual contact 45b is conducted to the common contact 45c.

The outputs of the AND gates 53, 54, 55 are input in parallel to the OR gate 48, and the inverted signal of the comparator 56 is input. Therefore, the OR gate 48 is connected to the AND gates 53, 54, 55
Output a high-level signal, or output a high-level signal when the comparator 56 outputs a low-level signal.

The outputs of the comparators 57 and 58 are input to the AND gate 53 in parallel. Thus the to the non-inverting input terminal of the comparator 57 is input operational electricity quantity F _{'OUT (n)} from the first calculation unit 37, sets the electric quantity F _O from a minimum hydraulic pressure setting section 59 to the inverting input terminal is input Is done. The minimum hydraulic pressure setting section 59 sets an electric quantity corresponding to the minimum hydraulic pressure required by the actuator 4 during braking.

The non-inverting input terminal of the comparator 58 has a decreasing speed setting unit 60.
Is connected to the inverting input terminal, and a decreasing speed calculating unit 61 is connected to the inverting input terminal. The minimum decrease amount setting unit 60 controls the braking oil pressure in order to avoid a decrease in the braking oil pressure due to a change in the operation amount corresponding electric amount F _{OUT (n)} corresponding to a slight change in the depression force of the brake pedal 1 during braking. electrical loss amount setting reduced electricity quantity [Delta] F _D ranges do not want exert is, the vehicle speed V _R, and computing the electric quantity F is inputted from the second holding unit 62 is inputted from the vehicle speed detecting section 39 _{'OUT (n} It is calculated according to the following equation (4) using _-1) .

ΔF _D = ΔF _D0 × (K ₂ × V _R ) × (C ₁ × F ' _{OUT (n-1)} ) (4) where ΔF _D0 is a reference value, and K ₂ and C ₁ are coefficients. _Where F ′ _{OUT (n−1)} is the calculated amount of electricity obtained in the previous control cycle, and the second holding unit 62 is connected to the first calculation unit 37. According to the equation (4), setting reduces electric quantity [Delta] F _D would vehicle speed V _R and the braking operation amount increases as the atmospheric.

In the decreasing speed calculating section 61, a calculation is performed in which the calculated electric quantity F ′ _{OUT (n)} obtained by the first calculating section 37 is subtracted from the electric quantity F _{IN (n)} held by the first holding section 49. As a result, the amount of reduction in the amount of braking operation per unit time can be obtained. Thus comparator 58, an electrical quantity corresponding to the decrease rate of the amount of braking operation outputs a high level signal when less than the set decreased electricity quantity [Delta] F _D.

In this way, the AND gate 53 _outputs F ' _{OUT (n)} > F ₀
A high-level signal is output when a and _{(F IN (n) -F '} OUT (n-1)) is <[Delta] F _D is.

The output signal of the comparator 57 is also input to the AND gate 54 while the output signal of the comparator 57 is inverted. Therefore, F ′ _{OUT (n)} ≦ F ₀ and (F _{IN (n)} −
_{F 'OUT (n-1)} ) the AND gate 54 outputs a high level signal when a <[Delta] F _D.

Further, the output signal of the comparator 58 is inverted and input to the AND gate 55, and the output signal of the comparator 56 is input. Thus, the output signal of the decreasing speed calculating section 61 is input to the inverting input terminal of the comparator 56, and the output signal of the decreasing rate setting section 63 is input to the non-inverting input terminal. Thus, the decrease ratio setting unit 63 reduces the set amount in order to limit the decrease ratio of the applied electric amount when the manipulated variable corresponding electric amount F _{OUT (n)} is decreasing to such a degree that the vehicle driver does not feel uncomfortable. Electric quantity ΔF _D
The maximum reduction amount ΔF _DMAX is set to be larger than the maximum reduction amount ΔF _DMAX using the vehicle speed V _R from the vehicle speed detection unit 39 and the calculated electric quantity F ′ _{OUT (n−1)} from the second holding unit 62. The maximum decrease amount ΔF _DMAX is determined based on the equation (5).

ΔF _DMAX = ΔF _DMAX.0 × (K ₃ × V _R ) × (C ₂ × F ' _{OUT (n-1)} ) (5) where ΔF _DMAX.0 is a reference value, and K ₃ , C ₂ is a coefficient. According to the first (5), the maximum decrease amount [Delta] F _DMAX will increase as the vehicle speed V _R and the braking operation amount increases.

Therefore, from the comparator 56, (F _{IN (n)} −F ′ _{OUT (n)} ) <
A high-level signal is output when ΔF _DMAX and an AND gate
From 55, so that _{ΔF D ≦ (F IN (n} ) -F 'OUT (n)) < high-level signal when the [Delta] F _DMAX is output.

The outputs of the first holding unit 49 and the decrease ratio setting unit 63 are input to a third calculation unit 64, and the third calculation unit 64 calculates (F
_{IN (n)} −ΔF _DMAX ) is executed.

By the way, a switch 66 that is turned on in response to the output of the AND gate 53 being at a high level is provided between the individual contact 47a of the changeover switch 47 and the first holding unit 49, and the individual contact 47a OR between the first operation unit 37 and
A switch 67 that is turned on when the output of the gate 65 becomes high level is provided.
A switch 68 that is turned on in response to the output of the comparator 56 attaining a high level is provided between the arithmetic unit 64 and the arithmetic unit 64. Also said
The output signals of the AND gates 54 and 55 are input to the OR gate 65.

According to this control unit 28, when allowed to increase the amount of braking operation from zero applied electric quantity F _IN changes as shown in Figure 5. That is, at the start of braking, the changeover switch 47 is in the state shown in FIG. 2, and the changeover switch 45 is also kept until the increase rate of the braking operation amount exceeds the set amount, that is, the maximum increase amount ΔF _IMAX set by the increase ratio setting section 51. There is even the second illustration. When the operation amount corresponding electrical quantity F _OUT in this state is less than the set electric quantity F _I that is set by the dead zone setting unit 44 remains changeover switch 41 is in the second illustrated, the applied electrical quantity F _IN
Remains at zero. When the manipulated variable corresponding electric quantity F _OUT exceeds the set electric quantity F _I , the common contact 41c and the individual contact 41a of the changeover switch 41 become conductive, and the operation electric quantity F ′ _OUT calculated by the first operation section 37 is applied. It is output from the output unit 36 as the electric quantity _FIN .

Next, the increasing rate of the braking operation amount increases, and the maximum increasing amount Δ
When F _IMAX is exceeded, the common contact 45c of the changeover switch 45 conducts to the individual contact 45a, and the applied electric quantity F _IN becomes the maximum increase ΔF _IMAX
Are sequentially added.

When the braking operation amount decreases, the applied electric amount _FIN changes as shown in FIG. That is, when the braking operation amount is reduced, the common contact 47c of the changeover switch 47 is electrically connected to the individual contact 47a. In this state, the output from the output unit 36 changes according to the switching of the switches 66, 67, 68. That is, F ′ _OUT > F ₀ and (F _IN −
The output of F _'OUT) <ΔF AND gate 53 when the _D becomes high level, the output of the first holding portion 49 is output from the output unit 36, the applied electrical quantity F _IN is not changed. The 'A _{OUT ≦ F 0 (F IN -F} ' F OUT) ≧ ΔF AND gate 5 when a _D
4 output becomes high level, and the OR gate 65
Becomes high level, the output unit 36 outputs an applied electric quantity F _IN equal to the calculated electric quantity F ′ _OUT calculated in accordance with the manipulated _variable . ΔF _D ≦ (F _IN −F ′ _OUT ) ≦ ΔF
_{When DMAX} is reached, the output of the AND gate 55 goes high and the output of the OR gate 65 goes high accordingly, so that the output unit 36 equals the calculated electric quantity F ' _OUT calculated in accordance with the manipulated variable. The applied electric quantity _FIN is output. Further, when (F _IN −F ′ _OUT )> ΔF _DMAX , the output unit 36 subtracts the maximum reduction amount ΔF _DMAX from the previous applied electric amount F _IN from the output unit 36 in response to the output of the comparator 56 becoming high level. the amount is outputted as the applied electrical quantity F _IN.

Next, the operation of this embodiment will be described.
In the first calculation unit 37 in 28, the change rate with respect to the operation amount of the brake pedal 1, that is, the braking operation amount, is set to the switching set value F.
Two types of calculation electric quantity F ' _{OUT which} are different from _OUT.0
Is calculated, and the applied electric quantity F _IN according to the calculated electric quantity F ′ _OUT is input to the electric operating section 16 of the antilock brake 4, so that at the start of braking, the braking oil pressure is quickly raised according to the braking operation. Operating the brake device quickly, and at the time when the amount of braking operation becomes large, avoid applying excessive braking oil pressure to the brake devices B _FL , B _FR , B _RL , B _RR As a result, the durability can be improved and the consumption of the brake oil can be prevented from unnecessarily increasing.

Moreover switching換設value F _OUT.0 are those that are set to increase in accordance with the vehicle speed V _R, it is possible to cope with the vehicle body of the inertial force changes due to change in the vehicle speed V _R.

At the time of the antilock control, the switching set value F _OUT.0 at the start of the antilock control is fixed, and the applied electric quantity F _{IN with} respect to the braking operation amount is fixed at the fixed switching set value F _OUT.0.
Is varied, so that an unnecessary large braking oil pressure is not output from the actuator 4 at the time of the anti-lock control, so that the durability is improved and the consumption of the braking oil is unnecessary as described above. It can be prevented from increasing.

Also, when the amount of braking operation is greater than or operation amount corresponding to a predetermined value or set electric quantity F _0, less than the quantity of electricity F _OUT is set decreased electricity quantity [Delta] F _D corresponding to the braking operation amount input to the input unit 35 When it decreases, the applied electric quantity F _IN does not change,
Since the applied electric quantity F _IN is decreased when the electric quantity is smaller than the set decrease electric quantity ΔF _D, it is possible to avoid a decrease in the braking oil pressure due to a slight change in the depression force of the brake pedal 1 during the braking and to prevent the chattering of the control. By avoiding this, it is possible to reduce the brake hydraulic pressure only when the pedal effort is reliably reduced.

Moreover setting decrease electric quantity [Delta] F _D is intended to be set to increase in response to the vehicle speed V _R and the braking operation amount increases, a change in the inertial force accompanying the change in vehicle speed V _R,
In addition, more precise control can be performed in response to a change in the braking force due to a change in the braking operation amount.

Furthermore, when the amount of change per unit time of the braking operation amount exceeds a predetermined value, the change amount of the applied electric amount F _IN is set to a predetermined value, that is, when (F ′ _OUT −F _IN ) exceeds the maximum increase amount ΔF _IMAX when the pressure is increased, the applied electric amount is changed. The amount of change in the amount F _IN is the maximum increase amount ΔF
And _IMAX, the vacuum when (F _IN -F _'OUT) is the maximum decrease amount Δ
When F _DMAX is exceeded, the amount of change in the applied electric quantity F _IN is set to the maximum decrease amount ΔF _DMAX, and in other cases, the applied electric quantity F _IN is changed in accordance with the braking operation amount. Unnecessary pressure increase and pressure reduction can be prevented while avoiding undesired fluctuations and preventing the vehicle driver from feeling uncomfortable.

Moreover, the maximum increase ΔF _IMAX and the maximum decrease ΔF
_By setting _DMAX to increase as the vehicle speed V _R and the amount of braking operation increase, the vehicle speed V _R
Thus, more precise control can be performed by coping with the change in the inertial force due to the change in the braking force and the change in the braking force due to the change in the braking operation amount.

FIG. 7 shows a second embodiment of the present invention, and portions corresponding to the above-described first embodiment are denoted by the same reference numerals.

The electrically operated actuators 4 _FL and 4 _FR are individually connected to the left front wheel brake device B _FL and the right front wheel brake device B _FR , respectively, and the left rear wheel brake device B _RL and the right rear wheel brake device B _{RR are connected.} Has an electrically operated actuator 4 _R
Are commonly connected and their actuators 4 _FL , 4 _FR , 4 _R
Is controlled by the control means 28 '. Thus, the normally-open electromagnetic inflow valve 6 as the anti-lock control valve shown in the first embodiment 6
_FL , 6 _FR , 6 _R and the normally closed electromagnetic outflow valve 7 _FL , 7 _FR , 7 _R are omitted. Each of the actuators 4 _FL , 4 _FR , 4 _R has the same configuration as the electrically operated actuator 4 shown in FIG.

Thus even if the 'are possible anti-lock control of each wheel by controlling individually, yet the control unit 28' each actuator 4 _FL, 4 _FR, 4 _R actuating the control means 28 of the first embodiment With the same configuration as the control means 28 in the example, the same effect as in the first embodiment can be obtained.

C. Effects of the Invention As described above, according to the first feature of the present invention, when the amount of decrease in the amount of braking operation is equal to or less than the predetermined amount while the amount of braking operation is equal to or more than the predetermined value, the amount of applied electricity is constant. When the braking operation amount decreases beyond a predetermined reduction amount, the applied electric amount is allowed to decrease, so that the braking hydraulic pressure acting on the brake device when the braking operation amount decreases regardless of the driver's intention. Fluctuation is avoided, and stable braking is possible.

Further, according to the second feature of the present invention, since the predetermined decrease amount is largely changed as the braking operation amount is increased, it is possible to avoid a change in responsiveness according to a change in the braking force.

Further, according to the third aspect of the present invention, since the predetermined decrease amount is largely changed as the vehicle speed increases, it is possible to avoid a change in responsiveness in response to a change in braking force caused by a change in vehicle speed. Can be.

[Brief description of the drawings]

1 to 6 show a first embodiment of the present invention. FIG. 1 is a hydraulic circuit diagram, FIG. 2 is a circuit diagram showing main components of the control means, and FIG. 3 is a braking operation. FIG. 4 is a graph showing a change in the switching set value depending on the vehicle speed, FIG. 5 is a graph showing a change in the applied electricity amount when the brake hydraulic pressure is increased, and FIG. FIG. 6 is a graph showing a change in the amount of applied electricity when the brake hydraulic pressure is reduced, and FIG. 7 is a hydraulic circuit diagram showing a second embodiment of the present invention. 4,4 _FL , 4 _FR , 4 _R …… Electrically operated actuator

Claims (3)

(57) [Claims] A brake hydraulic pressure control method for a vehicle, wherein the applied electrical quantity of an electrically actuated actuator that outputs a brake hydraulic pressure that increases in accordance with an increase in an applied electrical quantity is set in accordance with a braking operation amount. When the amount of braking operation is equal to or greater than a predetermined value and the amount of decrease in the amount of braking operation is equal to or less than the amount of predetermined reduction, the applied amount of electricity is kept constant. A method for controlling a vehicle brake hydraulic pressure, characterized by allowing a reduction in the brake pressure. 2. The method according to claim 1, wherein said predetermined amount of decrease is largely changed as the amount of braking operation increases. 3. The brake hydraulic pressure control method for a vehicle according to claim 1, wherein the predetermined decrease amount is changed largely as the vehicle speed increases.