JPH03208758A - Brake pressure controller - Google Patents

Abstract

PURPOSE:To smooth the regulation of carwheel brake pressure, by detecting a road surface friction coefficient at the time of the start of carwheel brake pressure regula tion, and making the brake pressure regulation at the time of the start of carwheel brake pressure regulation an appropriate one that copes with a road surface condition. CONSTITUTION:Pressure regulating means 3, 3A, 4, 4A whose purpose is to regulate brake pressure, are provided at the middle of connecting brake liquid pipe passeges between brake pressure surfaces including a master cylinder 2 and respective carwheel brakes 6-9, and when these are controlled by means of an electronic controller 10 according to a vehicle operation condition, a reference speed and the acceleration of the reference speed are operated from the output of respective carwheel speed detecting means 12fr-12rL. Also, whether carwheel brake pressure regulation is needed or not is decided on the basis of variables (a slip rate, a carwheel acceleration) includ ing a carwheel rotation speed and the reference speed. And a road surface mu is esti mated from the acceleration of the reference speed at the time of carwheel brake regulation need having been decided, and the electric current values or respective pressure regulating means 3, 3A, 4, 4A are determined in coping with this road surface mu.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a device for controlling wheel brake pressure, and in particular, the present invention relates to a device for controlling wheel brake pressure. So-called anti-skid control lowers the wheel brake pressure to lower the deceleration slip of the axle when the slip is likely to become excessive, or when the acceleration slip of the wheels relative to the road surface is likely to become excessive when the vehicle is trying to accelerate. The present invention relates to a brake pressure control device used for so-called traction slip control, etc., which increases wheel brake pressure to reduce wheel acceleration slip at certain times.

(Prior art) -4- For example, in the above-mentioned anti-skid control, conventionally, an on-off solenoid valve is used for high pressure connection to connect the wheel brake to the brake mask cylinder, and a low pressure connection is used to connect the wheel brake to drain pressure (low pressure). Open/close solenoid valves are used for wheel brake pressure control (for example, Japanese Patent Publication No. 51-6308).
(Japanese Patent Application Laid-Open No. 62-125942).

When the brake pedal is depressed, brake pressure (high pressure) is applied to the wheel brakes from the brake mask cylinder via the on/off solenoid valve for high pressure connection, and the braking force of the wheels reduces the rotational speed of the wheels, but if the road surface is frozen. When the wheels are dirty with oil or other slippery substances, the friction coefficient of the wheels against the road surface is low, causing the wheels to slip against the road surface, and although the vehicle is moving at a relatively high speed, the wheels are affected by the braking force. Rotation speed decreases rapidly. For example, when the wheels stop, the wheels slide on the road surface, making it difficult to steer (change the direction of travel) using the steering wheel, and the braking distance from when the brake pedal is depressed until the vehicle stops increases. In order to prevent this, a wheel slip rate is calculated based on the wheel rotation speed and a reference speed based on it (vehicle estimated speed), and this slip rate and the acceleration (increase, decrease, etc.) of the wheel rotation speed are calculated as necessary. If the wheels are about to lock up (the vehicle is moving but the wheels have stopped rotating) based on the vehicle speed, etc., the solenoid on-off valve for the high-pressure connection is closed (cut off), and the solenoid on-off valve for the low-pressure connection is closed (cut off). Open (flow) to reduce wheel brake pressure. When the rotational speed of the wheels increases, the electromagnetic on-off valve for high-pressure connection is opened and the electromagnetic on-off valve for low-pressure connection is closed to increase the wheel brake pressure (a combination of pressure reduction mode and pressure increase mode). By repeating this process, the wheel brake pressure is controlled so that the slip of the wheels with respect to the road surface is within a predetermined range, the steering effect of the steering wheel is produced, and the braking distance is shortened.

In the above-described anti-skid control, the wheel brake pressure is switched in a binary manner, so that the wheel brake pressure fluctuates roughly. Therefore, when the acceleration of wheel rotation increases to a certain extent and enters a certain range after pressure reduction, both the high pressure connection and low pressure connection solenoid on-off valves are closed (cut off) to maintain the wheel brake pressure at that value. (hold), and when the wheel acceleration increases further, the electromagnetic on-off valve for high pressure connection is opened (combination of pressure reduction mode, hold mode, and pressure increase mode).
．． In order to more smoothly control the wheel brake pressure, and to replace the conventional two open/close solenoid valves with one solenoid switching valve, for example, in the anti-skid control of Japanese Patent Application No. 62-270795, it is possible to switch from pressure reduction mode to In the hold mode while moving to the pressure increase mode, pressure reduction and pressure increase are switched alternately in a relatively short cycle, and the pressure increase duty during the repetition [pressure increase time / (pressure increase time + pressure reduction time)] X
100%] gradually. Patent application filed by the applicant in 1983
-190900 and the said patent application 1986-2707
The anti-skid control device No. 95 uses an electromagnetic switching valve in order to simplify the valve device for brake pressure control, and a single electric coil drives the valve body to control the wheel brakes. Selectively connect to mask cylinder and drain pressure.

-7- (Problems to be Solved by the Invention) In this type of brake pressure control, it is preferable to detect the friction coefficient μ of the road surface and control the brake pressure accordingly. When the wheel slip rate and wheel acceleration enter a certain set range, it is determined that caution is required for slipping, and the wheel brake pressure begins to be reduced.Afterwards, the wheel slip rate and wheel acceleration are tracked so that the wheel slip rate falls within a predetermined appropriate range. Furthermore, while pressure increases, holds, and decreases are repeated in order to achieve vehicle deceleration as quickly as possible, the friction coefficient of the road surface μ is estimated, and the timing of pressure increase, 2-hold, pressure reduction, etc. is adjusted according to the estimated value. This is the μ estimate after the first depressurization. However, since there is no indication of how much pressure should be reduced initially, the initial pressure reduction may turn out to be an excessive pressure reduction, followed by pressure increase, which tends to result in repetition of pressure reduction/pressure increase, that is, fluctuations in the wheel brake pressure.

Therefore, by estimating μ at the beginning of the first depressurization and setting the initial decompression pressure based on this, the wheel brake pressure can be adjusted smoothly and quickly by minimizing the frequency of repeating increases and decreases. It is preferable to prevent the wheels from slipping excessively and to decelerate the vehicle body as quickly as possible.

In the anti-skid control device disclosed in Japanese Patent Application Laid-Open No. 60-35647, μ between the wheels and the road surface is estimated from the slip rate of the wheels and the wheel acceleration. This is based on the property that μ forms a mountain with a peak at a slip rate of about 20%.

However, in reality, this μ estimation is possible during brake pressure control after the reduction of wheel brake pressure has started.
This type of μ estimation is impossible before the wheel brake pressure is not started to be reduced and the wheel brake pressure is unknown and undefined before brake pressure control.

In wheel brake pressure control to prevent excessive wheel slippage, the present invention detects the coefficient of friction μ of the road surface at the start of wheel brake pressure adjustment, and adjusts the brake pressure at the start to an appropriate level corresponding to the road surface condition. The first objective is to properly set the initial brake pressure setting when the wheel brake pressure control is opened 'M1, and adjust the wheel brake pressure smoothly and quickly. Prevents excessive slippage and decelerates the vehicle body (
The second purpose is to perform acceleration (in the case of braking slip suppression) or acceleration (in the case of acceleration slip suppression) as quickly as possible.

[Structure of the invention]

(Means for Solving the Problems) The brake pressure control device of the present invention has a brake pressure source (2.1
8 to 20); Pressure adjustment means (3; 33A, 34A) located between the brake pressure source (2.18 to 20) and the wheel brake (6) to adjust the wheel brake pressure; equipped with the wheel brake (6); Wheel speed detection means (12fr) that detects the rotational speed of the wheel (FR); Based on the wheel rotational speed detected by the wheel speed detection means (12fr), the reference speed (Vs) and the acceleration (Vsd) of the reference speed (Vs) are
); a determining means (11) that determines whether wheel brake pressure adjustment is necessary based on variables (slip rate, wheel acceleration) including wheel rotational speed and reference speed (Vs); and determining means (11) for estimating the friction coefficient μ of the road surface from the acceleration (Vsd) at the reference speed (Vs) when the means (11) determines that wheel brake pressure adjustment is necessary; Set the wheel brake pressure adjustment parameter (
means (11) for setting the current value of 3; mode boundary value such as in FIG.
means for determining the current value (current value; pressure regulation mode shown in Figure 13a, etc.) (
11);

Therefore, the brake pressure control device according to the first aspect of the present invention includes: a brake pressure source (2.18 to 20); an electric coil (123);
A pressure control valve device (3) which is located between the brake pressure source (2.18 to 20) and the wheel brake (6) and applies pressure to the wheel brake (6) corresponding to the current value of the electric coil (123). ); Electric coil of pressure control valve device (3) (
'123) energizing means (13a, 11) for energizing
Wheel speed detection means (12fr) that detects the rotational speed of the wheel (FR) equipped with the H wheel brake (6); Based on the wheel rotational speed detected by the wheel speed detection means (12fr), the reference speed (Vs) and Calculating means (11) for calculating acceleration (Vsd) of reference speed (Vs); calculates wheel brake pressure adjustment requirements based on variables (wheel slip rate, wheel acceleration) including wheel rotational speed and reference-11-speed (Vs); determining means (11) for determining whether or not to adjust the axle brake pressure (Ptic);
) and energizes the current value (Ii) to bring the wheel brake pressure (PνC) to the wheel brake (6).
3a, II) Brake pressure control means (].1)
;

Furthermore, the brake pressure control device according to the second aspect of the present invention includes a brake pressure source (2, 1.8 to 20); a brake pressure source (2, 1.8 to 20); A switching valve device (33A, 34A) that selectively connects the high pressure and low pressure of the source (2.18 to 20); a drive that selectively determines the switching valve device (33A, 34A) to the high pressure connection and the low pressure connection. Means (13c, 13d); Wheel speed detection means (12fr) for detecting the rotational speed of the wheel (FR) equipped with the wheel brake (6); Based on the wheel rotational speed detected by the wheel speed detection means (12fr); Standard speed (Vs) and acceleration of standard speed (Vs) (Vsd
); a determining means (11) that determines whether wheel brake pressure adjustment is necessary based on variables (slip rate, wheel acceleration) including wheel rotational speed and reference speed (Vs); ; and a straight line defined by pressure adjustment mode determining parameters (KIL, GIL, etc.) corresponding to the acceleration (Vsd) of the reference speed (Vs) when the determining means (11) determines that wheel brake pressure adjustment is necessary: Fig. 13a, etc.) is determined, and the state quantity (slip rate, wheel acceleration) indicating the behavior of the wheel is compared with the parameter to determine the pressure regulation mode to be executed, and the drive means (13c, 13d) is operated in the determined mode. A brake pressure control means (11) for energizing the brake pressure is provided.

Note that symbols and explanations inside brackets indicate corresponding elements and corresponding matters in the embodiments described later with reference to the drawings.

(Function) When the determining means (1l) determines that wheel brake pressure adjustment is required, the wheel brake pressure is reduced (in the case of braking slip) or increased (in the case of acceleration slip) due to braking or acceleration so that the wheel slip rate is high to some extent. is necessary. The implementation of brake slip suppression will be explained below. When it is determined that the brake pressure needs to be adjusted for the first time, the pressure has not yet been reduced, so the brake pressure in the wheel brakes is high enough to cause a certain amount of slip. is added, and the acceleration of the vehicle speed (in this case, it is braking, so it is a negative value, that is, deceleration. Therefore, hereinafter referred to as deceleration) is approximately proportional to the coefficient of friction μ of the road surface against the wheels, so at this deceleration Calculate the μ corresponding value. Therefore, the road surface condition can be determined from the calculated μ corresponding value, and brake pressure control corresponding to the road surface condition (μ) can be started.

Therefore, the appropriate wheel brake pressure for the road surface μ is proportional to the road surface μ, as shown in FIG. 2a, for example.
Appropriate wheel brake pressure can be calculated accordingly. In the first aspect of the present invention, the brake pressure control means (11), in response to the determination of the need for wheel brake pressure adjustment by the determination means (11),
Since the wheel brake pressure (Pvc) corresponding to the deceleration (Vsd) of the reference speed (Vs) is calculated, this wheel brake pressure (Pwc) is an appropriate wheel brake pressure corresponding to the road surface μ. However, the brake pressure control means (1
) brings the current value (Ii) to the wheel brake 14-(6).
a, 11), and the energizing means (13a, 11) energizes the electric coil (123) of the pressure control valve device (3), so the determining means (11) determines that wheel brake pressure adjustment is required. At this time, an appropriate wheel brake pressure (Pvc) corresponding to the road surface μ is set for the wheel brake (6).

In this way, when it becomes necessary to adjust the brake pressure, the initial wheel brake pressure is the brake pressure that corresponds to the road surface μ, so over-decreasing or over-braking is less likely to occur, and the wheel brake pressure can be adjusted smoothly. The vehicle decelerates as quickly as possible.

In the second aspect of the present invention, the brake pressure control means (l1) adjusts the pressure in response to the deceleration (Vs) of the reference speed (Vs) when the determining means (11) determines that the wheel brake pressure adjustment is necessary. Parameters for mode determination (straight lines defined by KIL, GIL, etc.: Fig. 2a, etc.) are determined, and the pressure regulation mode to be executed is determined by referring to this, so the pressure regulation mode corresponds to the road surface μ. The initial wheel brake pressure when it becomes necessary to adjust the brake pressure is the brake pressure that corresponds to the road surface μ, so over-decreasing or over-braking is less likely to occur, and the wheel brake pressure can be adjusted smoothly. Moreover, the deceleration of the vehicle body becomes as fast as possible.

Although the mode of braking slip suppression has been described above, the present invention can be similarly implemented in acceleration slip suppression (traction slip control).

In the acceleration slip suppression control, the above-mentioned deceleration (acceleration at the reference speed, absolute value of a negative value) is read as acceleration in the narrow sense (acceleration at the reference speed, absolute value of a positive value), and Brake pressure reduction can be read as pressure increase, and pressure increase can be read as pressure reduction.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

(Embodiment 1) FIG. 1a shows a first embodiment of the present invention. When the driver depresses the brake pedal 1, the brake pressure corresponding to the amount of depressing is applied to the brake 6 of the front right wheel FR and the brake 6 of the front left wheel FL through the pressure control valve devices 3, 3A, 4 and 4A. It is applied to the brake 7, the brake 8 of the rear right wheel RR, and the brake 9 of the rear left wheel -16-RL.

The pressure control valve devices 3.3A, 4 and 4A connect the wheel brakes 6 to 9 to the brake pressure output port of the brake mask cylinder 2 (maximum pressure increase setting) when their electric coils are not energized.

This output port communicates with a pump l8, 18A6 high-pressure output (discharge) port driven by an electric motor l9. A reservoir 20.20A is connected to the low pressure output (suction) port of the pump 18, 18A. The pressure control valve devices 3.3A, 4 and 4A apply a brake pressure to the wheel brakes 6-7 that is inversely proportional to the current value when their electric coils are energized. This brake pressure is formed based on the current value of the electric coil, the output pressure of the brake mask cylinder 2, the discharge pressure of the pumps 1B and 18A (both high pressure), and the suction pressure (drain pressure) of the pump 18.18A. (decompression setting).

The rotation speeds of the front right wheel FR, front left wheel FL, rear right wheel RR, and rear left wheel RL are determined by speed sensors 1, 2fr, 1
2fL+ 1 2rr and 12rL detect -1
7- Ru.

The brake oil in the reservoir 20 is sucked by the pump 18 and supplied to the first pressure control valve device 3 and the fourth pressure control valve device 4A, and the brake oil in the reservoir 20A is sucked by the pump 18A.
and is supplied to the second pressure control valve system [3A] and the third pressure control valve system 4.

Electric coils of the first to fourth pressure control valve devices 3, 3A, 4 and 4A, electric motor 19 and speed sensor 12fr~
12rL is connected to the electronic control device 10.

FIG. 1b shows the configuration of the first pressure control valve device 3. The main body of this device 3 is a solenoid valve 120. To explain this first, the spool 122 of the solenoid valve 120 is a magnetic material.
In the internal space of the case member 119, there are forward (left) and backward (
right) move. A ring-shaped flow groove 118 is formed on the inner surface of the case member 119 with which the first person's cover 121 communicates, and a ring-shaped flow groove 118 is formed apart in the axial direction of the case member 119 and with which the second person's cover 128 communicates. A -18- shaped flow groove 117 is formed.

A ring-shaped groove 134 that can communicate with the flow grooves 118 and 117 is formed on the side surface of the magnetic spool 122 approximately in the middle of the flow grooves 118 and 117, and the groove width is as follows: It is equal to the distance between flow grooves 118 and 117. An output boat 127 communicates with this groove 134.

When the spool 122 is at the left limit position (first position) as shown in FIG.
4 overlap, so the output port 127 communicates with the first person port 12l (brake pressure) through these grooves, but the groove 134 does not overlap with the second person port 128 (drain). pressure) and output boat 127
is shut off (pressure increase), and the pressure increase speed (pressure increase speed of the wheel brake 6) is the highest. When the spool 122 moves to the right, the overlap between the grooves 134 and 118 becomes smaller, so the pressure increase rate becomes lower, and the grooves 134 and 118 become smaller.
At a point that does not overlap with any of the points, the output boat 127 is
Both the first person's cover 121 and the -1912th person's cover 128 are cut off (held), and the pressure increase rate is zero (the pressure decrease rate is also zero).

When the spool 122 moves further to the right, the groove 134 overlaps the groove 117, and the output boat 127 is moved to the first input port 1.
21 is blocked, and communication is established with the second person port 128 (
pressure reduction), and the pressure reduction speed (pressure reduction speed of the wheel brakes 6) increases as the wheel moves to the right. The movement of the spool 122 to the right is
It is limited by a stopper 131, and when the right end of the spool 122 hits the stopper 131, it is the right limit position (second position), where the decompression speed is the highest.

Therefore, as the spool 122 gradually moves from the first position (left limit position) shown in FIG. The pressure increases gradually from "pressure increase" to a lower pressure increase rate, reaches a "hold" at a certain point, and beyond that point becomes "pressure decrease" at a lower pressure decrease rate, and then gradually becomes a higher pressure decrease speed.

The 201 spool 122 is pushed to the left by a compression coil spring 124. A hole is formed in the left end of the case member 119, and an output action chamber 125 is formed to the left of the hole, and a plunger 126 penetrating from the output action chamber 125 into the spool operation space is inserted into the hole. There is.

The output action chamber 125 communicates with the output port 127.

The spring 124 and electric coil 12 of the spool 122
3, the spring storage space 130 on the right side of the spool 122 and the plunger protrusion space 129 on the left side of the spool 122 are provided with the second person cover 128.
The communication hole 116 is connected to the communication hole 116. That is, since the plunger protrusion space 129 has drain pressure, the pressure in the space 129 is the same as that of the spool 122 of the plunger 126.
does not prevent movement to the right. When the pressure in the output port 127 increases, the pressure in the output action chamber 125 increases and tries to push the plunger 126 to the right. As a result, the spool 122 has an output action chamber 125 and a plunger 126.
The pressure of the output boat 127 acts as a right-hand driving force via.

However, even at the expected maximum wheel brake pressure, the left driving force provided by the spring 124 is greater, so when the electric coil 123 is de-energized, the spool 122 is It is in the first position shown in Figure 1b.

A yoke 132 is fixed to the right end of the case member 119, and an electric coil 123 is installed inside the yoke 132. A substantially middle portion of the inner cylindrical portion of the yoke 132 around which the electric coil 123 revolves is broken into a ring shape, and a non-magnetic ring 133 is attached thereto. When the electric coil 123 is energized, the electric coil 12 is attached to the hollow ring cylindrical yoke.
A magnetic flux is generated that interlinks with 3 and circulates around the electric coil 123, but a part of it spreads in the axial direction of the yoke 133 at the non-magnetic ring 133 and flows to the magnetic spool 122 to the right. exerts a magnetic attraction force that drives the spool 12
2 to the right.

The electric coil 123 is not energized and the spool 122 is in the first position.
When the brake pedal 22 is depressed to generate a certain brake pressure in the mask cylinder 2 when the brake pedal is in the first position shown in FIG.
1 8-1 34-output boat 127-filter 10
It flows to the wheel brake 6 through the path 6, and the brake pressure of the wheel brake 6 increases.

Since the overlap between the grooves 118 and 134 is maximum, the rate of increase in the brake pressure of the wheel brake 6 is the highest.

The relationship between the current value of the electric coil 123 and the output pressure of the output boat 127 is shown in FIG. 2b. As shown in FIG. 2b, the output pressure is inversely proportional to the current value of the electric coil 123. Note that the highest output pressure is input port 1.
This is the pressure value applied to 21.

When the brake pedal 1 is released, the brake mask cylinder 2 exerts a negative pressure on the first input port 121, and the brake oil of the wheel brake 6 flows through the filter 6 and the output port 1.
It returns to the mask cylinder 2 through the path of 27 first groove 134-118-lth input port 121-filter 102, but as long as the difference between the brake pressure of the wheel brake 6 and the pressure of the mask cylinder 2 is equal to or greater than a predetermined value. Even through the check valve 103, the brake oil in the wheel brake 6 returns to the mask cylinder 2.

When the brake pedal 1 is depressed, the mask cylinder 2 generates a certain brake pressure, the brake pressure of the wheel brake 6 increases to a certain extent, and a braking force is applied to the wheel FR. When the electric coil 123 is energized, a current is generated. The spool 122 moves to the right in accordance with the value, and during this movement, the groove 11
When the overlap of the groove 134 with respect to the mask cylinder 2 decreases and the pressure of the wheel brake 6 is lower than the output pressure of the mask cylinder 2 (brake pressure increasing process), the rising speed of the wheel brake 6 decreases. After the grooves 118 and 134 no longer overlap, the groove 134 starts to overlap with the output boat 127.
Drain pressure is added to the wheel brake 6, and the pressure of the wheel brake 6 begins to decrease. The rate of decline depends on the amount of overlap between grooves 134 and 117. When the pressure of the output boat 127 decreases, the force of the plunger 126 that pushes the spool 122 to the right decreases, and this causes the rightward driving force acting on the spool 122 (the driving force of the electric coil 123 + the plunger 12
6), and the spool 122 stops at a point where this rightward driving force is balanced with the leftward driving force by the compression coil spring 124, that is, at a position corresponding to the current value of the electric coil 123. Therefore, output port 127
The pressure of the (wheel brake 6) has a value corresponding to the current value of the electric coil 123. During this pressure reduction, brake oil flows from the wheel brakes 6 to the reservoir 20 via the path from the filter 106 to the output port 127.

The filter 102 removes dust from the brake oil supplied from the mask cylinder 2 to the wheel brakes 6 using the solenoid valve 12.
The filter 106 prevents dirt in the brake oil returning from the wheel brakes 6 to the mask cylinder 2 from entering the solenoid valve 120. These are installed to prevent the electromagnetic valve 120 from malfunctioning.

The check valve 103 prevents the flow of brake oil from the former to the latter between the mask cylinder 2 and the wheel brake 6, but allows the flow in the opposite direction. 1 is released), the brake oil of the wheel brake 6 is promptly returned to the mask cylinder 2, and the solenoid valve 120 is used to release the wheel brake pressure in the unlikely event that the solenoid valve 120 is malfunctioning. .

Drain pressure from mask cylinder 2 (second person cover 12
The check valve 104, which prevents the brake oil from flowing back to the mask cylinder 8) but allows the brake oil to flow in the opposite direction, returns the brake oil from the reservoir 20 to the mask cylinder 2 when the pressure is reduced. In addition, the above-mentioned “
When the pressure is reduced, the pump 18 is driven as described later, and the brake oil in the reservoir 20 is returned to the mask cylinder 2 by the pump 18. If brake oil remains in the reservoir 20, or if brake oil remains in the pump 18
Appears when there is a malfunction.

Although the configuration and operation of the first pressure control valve device 3 have been explained above, the second to fourth pressure control valve devices 3A, 4
The structure and operation of and 4A are also exactly the same as device 3.

FIG. 11 shows another configuration example of the pressure control valve device. This can also be used as the first pressure control valve system w3. In this case, the space on the left side of the spool 122 in the inner space of the case member 119 is an output action chamber 125, and the output boat 127 communicates with the groove 134 through the hole 114 of the spool 122 and the chamber 125. There is.

A compression coil spring 124 is housed in a space 204 on the right side of the spool 122, and an orifice 2
07 and the first person cover 121 through the communication hole 115.
are communicating. A nozzle 208 communicates with the space 204, and the nozzle 208 is closed at the left end of the plunger 209. The plunger 209 has a slot that is long in the left and right direction, and this slot is connected to the leaf spring 209.
10 is passing through. The leaf spring 210 drives the plunger 209 in the direction of closing the nozzle 20 (left drive). When the electric coil 123 is energized, the plunger 209 is pulled to the right, the plunger 209 opens the nozzle 208, and the pressure in the space 204 is increased to the input boat 1.
The pressure of plunger 2 is lower than that of plunger 2.
This corresponds to the position 09, that is, the current value of the electric coil 123. Then, since the pressure in the output action chamber 125 is higher than the pressure in the space 204, the spool 122 moves to the right.
The spool 122 moves to a position where the force by which the pressure of 04 drives the spool 122 to the left is equal to the force by which the spring 124 drives the spool to the left.

Since the force by which the space 204 drives the spool 122 to the left is determined by the current value of the electric coil 123, the position of the spool 122 corresponds to the current value.

According to the pressure control valve devices 3, 3A, 4, and 4A described above, the vehicle is decelerated as quickly as possible without causing excessive slip, for example, as shown in FIG. 2a, corresponding to the friction coefficient μi of the road surface. Since the wheel brake force pressure (optimal pressure) Pwc to be determined is determined, the energizing current value Ii that generates the required wheel brake pressure Pwc is determined from the energizing current value/output pressure characteristic shown in FIG. Current value 1i
By energizing the pressure control valve devices 3, 3A, 4, 4A, a desired brake pressure Pwc can be applied to the wheel brakes 6, 7, 8.9.

FIG. 3 shows the structure of the electrical control device 10 shown in FIG. 1a. As shown in FIG. 3, the electronic control device 10 includes a microcomputer (hereinafter referred to as CPU) 11, and inputs pulses for wheel speed detection to input ports IPI to IP4 of the CPU II via a waveform shaping circuit 12. Generator 12f
Wheel rotation synchronization pulses generated by r, 12fL, L2rr, and 12rL are given. CPUI 1 output port O
Solenoid driver 1 3 a − for PI~○P4
1 3 d are connected, which energize the electric coils 123 of the pressure control valve devices 3, 3A, 4.4A, respectively. Resistors 14a to 14d generate a voltage proportional to the energized current, and amplifiers 15a to 15d smooth the voltage to A.
/D converters 16a to 16d. The CPU II instructs the A/D converters 16a to 16d to perform digital conversion at the required timing, and transfers the digital data to the input port IP.
5 to read via IP8. A motor driver 13e is connected to the electric motor 19 that drives the pump 1'8.18A. The CPU 1 outputs an on (motor drive)/off (motor stop) signal to this motor driver 13e via an output port OP5.

FIG. 4 shows the control operation of CPU II. When the power is turned on (Step 1: hereinafter, the words "step" and "subroutine" will be omitted in the text), the CPU II initializes internal registers, counters, timers, etc., and outputs the standby output signal level to the output port. (low level 0) and permits interrupt processing in response to pulses generated by the pulse generators 12f'r to 12rL.

With this permission, for example, when the output of the pulse generator 12fr falls from the high level 1 to the low level O, the 12f
Write the count data of the time counter added to 12fr into the time count register assigned to r, restart the time counter, end this interrupt processing, and return to the main routine (Figure 4). . Similar interrupt processing is executed for other pulse generators. As a result, pulse generation period data that is inversely proportional to the rotational speed of each wheel is always written in the time count register assigned to each pulse generator.

In "Calculation of wheel speed and its acceleration" (3) in Fig. 4, first, for each wheel (each pulse generator), the wheel speed VwFR,V
Calculate wFL, VvRR, VwRL, and calculate wheel acceleration DvwFR, DvwFL, DvwRR, D from the wheel speed calculated last time and the wheel speed calculated this time.
Calculate vvRL.

The CPU II then calculates each wheel speed VwFR,V
A reference speed Vs, which is regarded as the vehicle speed, is calculated based on wFL, VwRR, and VwRL (4). The details of "calculation of reference speed Vs" (4) will be described later with reference to FIG.

Next, the CPU 1 calculates the reference speed average value by:
The data of nine registers Vsdl to Vsd-31-9 that store the deceleration of the past eight reference speeds and the deceleration calculated this time are set to Vsdl and Vsd3 to Vsd2.
The one of Sd9 is set to Vsd2,...■ The one of Sd9 is set to Vsd8
Then, the deceleration of the reference speed is calculated from the currently calculated reference speed Vs and the previously calculated reference speed and written into the register Vsd9 (9). As a result, the deceleration of the reference speed calculated this time and the deceleration of the reference speed calculated eight times in the past are written in the registers Vsd9 to Vsdl.

Here, the CPU II calculates the average value of the deceleration of the reference speed and writes it into the deceleration register Vsd (IOA).

In the following, the deceleration Vsd of the reference speed Vs is assumed to be the data (average value data) of the deceleration register Vsd.

Next, the CPU II calculates a time-series average value of the base speed Vs using a process similar to the average value calculation process described above, and writes it into the reference speed register Vs (IOB).

Next, the CPU 1 calculates the slip rate of each wheel based on the rotational speed of each wheel and the reference speed (average value) Vs of the reference speed register Vs (11). Slip rate S (%)
is -32-100X (reference speed Vs one wheel speed)/reference speed Vs.

Next, the CPU II sets the rFR pressure setting J (12FR
). In this case, the slip rate of the wheel FR is determined by referring to the data in the register FRF assigned to the wheel FR, which indicates whether or not the pressure control is being entered, and if it is 0 (not entering the pressure control), the slip rate of the wheel FR is determined. The relationship between and acceleration is
It is checked whether it is in the "anti-lock control start region" shown in FIG. 7 (22). If not, the process proceeds to the next rFL pressure setting J (12FL) and the pressure control of the wheel brakes 6 is not performed. .

When entering the "anti-lock control start region", that is, when the slip rate of the wheels FR increases, the register FRF
Write l indicating that pressure control has entered (23), and calculate the friction coefficient μ1 of the road surface from the deceleration Vsd at that time (
In this example, assuming that μi is proportional to Vsd,
μi=A−Vsd. A: constant, calculated as) L (24
). From μi, the required wheel brake pressure Pvc is calculated according to the relationship shown in FIG. 2a (25), and the required energizing current value -33-Ii is calculated according to the relationship shown in FIG. Write Ii=f(Pvc) to the current output register IFR (26)
. In the internal interrupt processing for output J(13) and current output, which will be described later, the electric coil 123 of the pressure control valve device 3 is
Turns on/on at the energizing duty where the time series average current value is ■1
When the energization is turned off, the output port 1 of the pressure control valve device 3
27, that is, the pressure of the wheel brake 6, becomes the pressure Ptic corresponding to Ii.

In this way, the initial pressure Ptzc of the axle brake 6 after entering the pressure control (before entering the pressure control, the output pressure of the mask cylinder 2 is directly applied to the wheel brake 6, so this initial pressure Pwc is the initial pressure Ptzc of the brake 6 After that, the contents of register FRF are 1, so rFR map control target hydraulic pressure calculation J (27)
Next, determine the wheel brake pressure (energizing current value) according to the pressure increase and decrease condition map shown in FIG. Its contents will be described later with reference to FIG.

After executing the rFR map control target hydraulic pressure calculation J (27), the CPU 1 calculates that the energizing current value (content IFR of the register IFR) calculated thereby is O (normally given by pressing the brake pedal). Check whether the setting is such that pressure is applied to the wheel brakes (pressure control for suppressing slip is not required) (28). If it is 0, pressure control of the wheel brakes 6 is terminated.
Clear register FRF (29). After clearing in this way, the I'FR pressure setting J (12
When proceeding to FR), since FRF=O, a new determination is made as to whether or not the FRF is in the "anti-lock control start region" shown in FIG. 7 (22).
When entering, the initial pressure is set in step 23 and thereafter.

After passing through the rFR pressure setting J (12FR) mentioned above, the CPU II next sets the rFL pressure setting (1 2FL).
, rRR pressure setting J (12RR) and rRL pressure setting J (12RL) are executed in this order. These contents are the same as in ``Pressure setting of rFR'' (12FR), and the determination of whether or not control of the brake pressures of the wheels 35, keys 7, 8, and 9 is necessary and the corresponding processing are performed in the same way.

Next, the CPU 1 executes the process of "output J (13). In this, register FRF for wheel brake 6 assignment, register FLF for wheel brake 7 assignment, register RRF for wheel brake 8 assignment, and register RRF for wheel brake 9 assignment. The contents of register RLF (FLF, RRF, and RLF correspond to FRF) are checked, and if any of them is 1, a high level 1 is output to output port OP5 to drive motor 19 (pump drive). )
However, when all are O, a low level O is output and the motor 19 is stopped (the pump is stopped). Furthermore, if the contents of any of these registers are 1, internal timer interrupts are enabled, and if all the contents are 0, internal timer interrupts are prohibited and power is stopped to all output ports OPI to OP4. Outputs a low level O that specifies.

If any of the contents of registers FRF, FLF, RRF and RLF is 1 and the internal timer interrupt is enabled, then the CPU 1 activates the pressure control valves 3, 3A, 4 and 4A every time the internal timer times out. By performing the output current value control (duty control + feedback control) and repeating this interrupt process, the energizing current value (time series average value ), registers IFR, IFL, IR
R and IRL (IFL, IRR and IRL are IF
(corresponding to R).

Although detailed illustration is omitted in FIG. 4, the above-mentioned subroutines 3 and 4 are repeated at a 5 msec period, and steps 5 to 13 are repeated at a 10 msec period. Also, the initial pressure set in step 26 is 20 msec.
The output is continued for a period c, and then the process proceeds to subroutine 27.

Next, referring to Fig. 5, "Calculation of reference speed Vs" (4)
Explain the contents. First, the speeds of the four wheels VvFR (
n) + Calculate the maximum value yvMax(n) of VvFL(n), VwRR(n) and VvRL(n) (
41). Note that n represents the calculation time. Next, the average value PIM of the wheel brake pressure when each wheel is locked (current value when the wheel is locked) is calculated (42), and the deceleration αDN (absolute value )
(43). If VwMax(n) is larger than the previously calculated reference speed Vs(n-1) - αDN, the currently calculated reference speed Vs(n) is set to Vs(n-1).
- Set it as aDN, otherwise set the reference speed Vs(n) calculated this time as VwMax(n) (44-46
).

Next, with reference to FIG. 6, "Map control target hydraulic pressure calculation J
The content of (27) will be explained. In this case, it is first checked whether the relationship between the wheel slip rate and the wheel acceleration is in the "target pressure increase region" of the pressure increase/reduction condition map shown in Fig. 10 (52 to 54), and if it is in that region. Target pressure increase mode information is set (55).

If it is not in that area, then check whether it is in the "hold area" (56.57). If it is in that area, hold output mode information is set (58). If it is not in the "hold region", it is checked whether it is in the "sudden pressure reduction region" (59.60), and if it is in the region -38, the sudden pressure reduction output mode information is set (61).

If it is not in the "rapid decompression area", decompression output mode information is set (62).

When determining the required mode in this way, when the target pressure increase mode information is set, the wheel brake pressure (energizing current value) is smaller (larger) than 80% of the hydraulic pressure (current) PI when the wheels are locked.
(65.66), and if it is smaller (larger) than 80%, write the current value for rapid pressure to the register (IFR if addressed to brake 6) (67). Big(
(small), write the current value for slow pressure increase to the register (6
8).

When the hold output mode information is set, the contents of the register (I'FR if addressed to brake 6) are not changed. When the sudden pressure reduction output mode information is set, the current value for sudden pressure reduction is set in the register (IF for brake 6).
R), and when the reduced pressure output mode information is set, the current value for reduced pressure output is written to the register. Therefore, if the sudden pressure reduction output mode information or the pressure reduction output pressure reduction mode information is set, the previous setting is the target pressure increase mode = 3.
9- Refer to whether it was information or hold output mode information (
63), then the previous wheel brake pressure is the lock pressure, so the register (if the wheel brake is 6, I
FR) pressure (current value) is written to the lock pressure register (lock pressure current value register addressed to brake 6) PI (64
).

Note that when target pressure increase mode information or hold mode information is set, in the output current value control (duty control + feedback control) using the internal timer interrupt described above, the , the current value is decreased by one step and the brake pressure is gradually increased by minimum steps. As a result, while the relationship between the wheel slip rate and the wheel acceleration is in the target pressure increase region shown in Fig. 10, the current value of the pressure control valve device gradually decreases, and the wheel brake pressure gradually decreases as shown in Fig. 9. It gets expensive. When the output current setting value reaches O, step 28 in FIG.
．． Register at 29 (FRF: For wheel brake 6)
is cleared, and the pressure control of the wheel brakes (6) ends. Note that the current value reduction speed when the hold mode information is set is lower than the current value reduction speed when the target pressure increase mode information is set.

FIG. 8 shows the change in wheel brake pressure during anti-lock control brought about by the brake pressure control described above.

Wheel brakes 6 to 8 (
Brake pressure is applied to the brake pressure (described below with respect to 6 only) and it increases (point A in Fig. 8). This increase in brake pressure causes the wheel speed and vehicle speed (Vs) to decrease, and when the relationship between the slip rate of the wheels 6 and the acceleration of the wheels 6 enters the "anti-lock control start region" in FIG. 7 (b), the fourth Step 2 in the diagram
3 to 26 are executed, and the brake pressure target value of the wheel brake 6 is set to Pvc in FIG. 2a (20κg/am in FIG. 8).
2 or less). With this setting, the brake pressure of the wheel brakes 6 decreases toward Pwc, and the deceleration of the wheels becomes smaller (see C to C). rFR in FIG. 4 20 msec after setting the target output of the pressure control valve device 3 to Pvc
map control target hydraulic pressure calculation" (27), it is determined to be in the "hold region" in FIG. The current value is reduced little by little in the series and the wheel brake pressure increases little by little, but during this time the rotation of the wheels FR is restored (c-2). In the next rFR map control target hydraulic pressure calculation J (27), it is determined that it is in the "target pressure increase region" shown in Fig. 10, and in this case, the lock pressure (P1) has not yet been detected, so as shown in Fig. 6. " by step 66.67
"Rapid pressure output" mode information is set, and the wheel brake pressure increases (2 to E: 10 msec). Next continuous rFR map control target hydraulic pressure calculation J
In (27), the "hold" mode information is set continuously, and the current value is gradually reduced in time series from the output current value when the "hold" mode is first set, and the wheel brake pressure is maintained at low speeds. During this time, along with the previous pressure increase, the rotational speed of the wheels decreases (e-he). Next rF
In the R map control target hydraulic pressure calculation J (27), the "r sudden pressure reduction" mode information is set (to), the lock pressure (current value) PI at that time is written to the lock pressure register, and the current value is set to a high value. (sudden pressure reduction value), thereby reducing the wheel brake pressure and restoring wheel rotation. next r
In FR map control target hydraulic pressure calculation J (27),
"Target pressure increase" mode information is established, and at this time, since there is a lock pressure PI, a gradual pressure increase output is performed, and the current value gradually decreases at a relatively slow speed, causing the wheel brake 6
The pressure of the wheel FR gradually increases and the rotational speed of the wheel FR decreases. Although not shown in FIG. 8, in the subsequent rFR map control target hydraulic pressure calculation J (27), "target pressure increase" mode information is continuously set, and the initial wheel brake pressure (current value) is 80% of the previous lock pressure (current value) PI
As above (or below), steps 66 and 68 in Figure 6
Set the slow pressure increase speed with , and set the wheel brake pressure (output current value)
is gradually increased (decreased) in time series using duty control + feedback control using internal timer interrupts. Finally, the output current value (value of register IFR) becomes O, and then register FRF is cleared (step 2 in Figure 4).
9). As a result, the energizing current value of the pressure control valve device 3 becomes O, and the pressure of the brake pressure line SPL (Fig. 1a) at that time is directly applied to the wheel brake 6 (the brake pressure control of the wheel FR is end).

Note that when there is a change in the road surface μ, such as when the road surface μ is low at the start of brake pressure control (start) and the road surface μ becomes high after the corresponding pressure reduction (RO to H), for example, the road surface μ may be low.
After performing c), the pressure is rapidly increased or slowly increased, and while doing this, the output current value becomes zero and brake pressure control is terminated, but the vehicle does not stop yet and becomes low μ again, as described above. Brake pressure control may be started again in the same state as at point .

In any case, the initial brake pressure (output pressure set to the pressure control valve device at the mouth point) is set to an appropriate value Pvc corresponding to the road surface μ.
Since the setting is set to
The axle brake pressure can be adjusted smoothly, and the vehicle speed (reference speed Vs) can be decelerated quickly.

-44- In addition, as mentioned above, the deceleration Vsd of the reference speed Vs is
The average value of nine calculated values from the present to the past (5 to 10 in Figure 4) is because in conditions where brake pressure control is required, changes in wheel rotational speed due to slips, etc. are relatively small. Therefore, since the reference speed Vs calculated based on the wheel rotation speed fluctuates relatively violently, the deceleration calculated based on it also fluctuates relatively violently, so it is smoothed over time to calculate the road surface μ. This is to stably and accurately calculate the corresponding deceleration. Also, the reference speed V
s is also taken as a time series average (IOB) and this average value is used to calculate the wheel slip rate (11 in Figure 4).The reason for this is that large fluctuations in the calculation reference speed may cause inaccurate calculation of the wheel slip rate. This is to prevent this from happening.

(Embodiment 2) FIG. 12a shows an outline of the system configuration of a second embodiment of the present invention. When the driver depresses the brake pedal 1, brake pressure corresponding to the amount of depressing is applied from the brake mask cylinder 2 to the brake 7 and the proportional valve of the front left wheel FL via the throttle valve 27 and the electromagnetic on-off valve 33. In addition, the brake 6 of the front right wheel FR and the proportional valve PVA are
join. The proportional valve Pv applies a brake pressure proportional to the brake pressure to the brake 8 of the rear right wheel RR, and the proportional valve PVA applies a brake pressure proportional to the brake pressure to the brake 9 of the rear left wheel RL. Add.

The electromagnetic on-off valves 33 and 33A are of a normally open type, and generally include a plunger that opens and closes a flow path between the mask cylinder 2 and the wheel brake, a compression coil spring that forces this plunger in the opening direction, and a compression coil spring that forces the plunger in the opening direction. It has a magnetic yoke and an electric coil that drive the plunger in the closing direction against the force of a compression coil spring.When the electric coil is de-energized, it is open (communication between the mask cylinder 2 and the wheel brake), and the electric coil When energized, it is closed (mask cylinder 2 and wheel brake are cut off).

46 Solenoid on-off valve 33, 33A and brake oil reverser 20
．． Electromagnetic on-off valves 34, 34A are inserted between 20A. These electromagnetic on-off valves 34, 34A have the same structure as the electromagnetic on-off valves 33, 33A, but are normally open, and are closed when the electric coil is not energized and open when energized.

The rotation speeds of the front right wheel FR, front left wheel FL, rear right wheel RR, and rear left wheel RL are measured by speed sensors 12fr, 1.
2fL, 1 2rr and 12rL are detected.

The brake oil in the reservoir 20 is sucked by the pump 18 and supplied to the oil flow path between the electromagnetic on-off valve 33 and the throttle valve 27, and the brake oil in the reservoir 2OA is sucked by the pump 18A.
The oil is sucked in and supplied to the oil flow path between the electromagnetic on-off valve 33A and the throttle valve 27A. Pump 18.18A is driven by electric motor 19.

Electric coils of electromagnetic on-off valves 33, 33A and 34, 34A, electric motor 19 and speed sensor 1 2fr-1
2rL is connected to the electronic control unit [10.

-47- The structure of the electronic control device [10] is shown in FIG. 12b.

The speed sensor 1 2fr-1 2rL is a Hall IC (including a Hall element that detects the height of the magnetic field and a binarization circuit that binarizes the detection signal), and is a gear-shaped permanent magnet ring coupled to the wheel axle. In response to the rotation of the motor, it generates electrical pulses with a frequency proportional to the speed of the rotation. These electrical pulses are applied to F/V converters 43A, 43 and 44A, 44. F/V converters 43A, 43 and 44A,
44 generates a voltage at a level proportional to the frequency of the input electrical signal and supplies it to the A/D conversion input terminal Afr-ArL of the microprocessor 1l.

Engine key switch EKS is attached to battery BA on the vehicle.
A constant voltage circuit 22 is connected thereto.

15a to 15h, the microprocessor 1
1 shows the brake pressure control operation of No. 1.

Referring first to FIG. 15a, microprocessor 11
When the switch EKS is closed and the constant voltage circuit 22 generates a constant voltage Vcc at a predetermined level, -48 ), clear the internal registers, counters, timers, etc., set L (pump stop: electric motor 19 is not energized) to output port MD, and output ports SL3 and SL4.
, outputs (latches) L (valve 43, 43A open, valve 44, 44A closed) to SL3A and SL4A (2).

The CPU 11 then calculates the wheel speed and acceleration (
3). FIG. 15b shows the details of calculation of the average wheel speed of wheels FL and RR and their acceleration.

In this case, the rotational speed vfL of the front left wheel FL and the rotational speed Vrr of the rear right wheel RR are read (3V, 4V
), their average speed V■s (5V) is calculated, and the acceleration Vmd (plus means acceleration, minus means deceleration) of the average speed vIIls is calculated (6v). In addition, the speed VfL
, Vrr is the wheel rotation circumferential speed (
172 (equal to the vehicle speed if the wheels do not slip on the road surface). Therefore, the average speed V
ms is expressed as: V+ns=VfL+Vrr-49-. Next, the average speed Vmp calculated last time (t 1 = 5 msec ago) and the average speed Vm calculated this time
The wheel acceleration Vmd is calculated from s (7v).

Next, in the same manner as the process shown in FIG. 15b, the front right wheel F
The rotational speed Vfr of R and the rotational speed ■rL of the rear left wheel RL are read, their average speed Vmsa is calculated, and the acceleration Vmda of the average speed vIIlsa is calculated.

Referring again to Figure 15a, the CPU II then calculates the reference speed Vs (4). This content is similar to that shown in FIG. 5 of the first embodiment. However, this second embodiment differs in that there are two sets of wheel rotation speed data (four sets for four wheels in the first embodiment).

Calculation of axle speed and its acceleration explained above (3)
and the calculation (4,) of the reference speed Vs is 5IIISeC
Repeat in cycles.

The CPU II then calculates the deceleration Vsd of the reference speed Vs (IOA). This content is similar to the processing from step 5 to IOA shown in FIG. 4 of the first embodiment.

50- The CPU I next calculates the time series average value of the reference speed Vs and writes it to the reference speed register Vs (IOB).
10msec from subroutine IOA to 121A
Repeat in cycles. However, output processing 1 (600
) and the output processing IA in the brake pressure control IA (121A), the timer start and start processing shown in Figs. Please note that this is executed in an integrated process, and the cycle is not 10 msec.

Next, in the subroutine 300, the CPU II calculates the slip rate of the wheels relative to the road surface Sp=(Vs-Vms)/Vs using the reference speed (time series average value) Vs and the wheel speed V■S, and similarly, the CPU II calculates the slip ratio Sp=(Vs-Vms)/Vs of the wheels with respect to the road surface. Calculate the slip ratio Spa=(Vs-Vmga)/Vs using
1 = Go to routine 121. First, the contents of the register FPC, which stores information indicating whether or not the adjustment of the brake pressure has proceeded, is checked (2l), and if the adjustment of the brake pressure has not yet proceeded (FPC=O), the contents of the register FPC are checked (2l). The slip rate Sp and wheel acceleration ■1 are expressed as shown in Fig. 7.
Check whether it is in the anti-lock control start area (
22).

If it is not in the "anti-lock control start area", proceed to the next "brake pressure control IAJ". If it is in the "anti-lock control start area", write 1 to the register FPC (23). The road surface μ is calculated from the deceleration Vsd (24). At this time, since the deceleration Vsd is proportional to the road surface μ, μ is calculated by multiplying Vsd by a coefficient (24).

Next, the determination parameter 1 is calculated in accordance with the calculated μ (500). This content is shown in FIG. 15c. Here, to explain the logic for determining the control mode as "pressure reduction", "pulse pressure reduction", "hold J", "r pulse pressure increase J" or "pressure increase", which of these is determined depends on the above μ and the above slip. Rate Sp Wheel acceleration - 52 - Speed Vmd is determined by the three values. When μ is low, the first
As shown in Fig. 3a, the control mode region is determined as shown in Fig. 13b when μ is medium, and as shown in Fig. 13c when μ is high (310 to 310 in Fig. 15c).
350). In Figures 13a-13c, the straight line (solid line) at the boundary between different modes is, for example, the straight line that separates "sudden decompression" and "pulse decompression" in Figure 13a. P”KI L-Vmd KI L -GI L, where K I L is the slope of the straight line, G
IL represents the position of the intersection with the horizontal axis (Vmd, Vmda). As can be seen by comparing these straight lines with Figure 13a (low μ), Figure 13b (medium μ), and Figure 13c (high μ), μ is small (the road surface is slippery). It shifts to the high acceleration side with a moderately large slope. This is to determine an appropriate brake pressure depending on the slipperiness of the road surface.

Referring again to FIG. 15a. After determining the determination parameters, CP'UII writes the mode data in the current mode register BMRs to the previous mode register BMRp (360).

The CPU II then determines the mode and writes the determined mode to the current mode register BMRs (370). This content is shown in Figure 15d. First of all, in this case. Substitute the current wheel acceleration Vmd into each of the straight lines in the group of straight lines (any of the ones shown in Figures 13a to 13c) identified in the above-mentioned ``Determination J of Judgment Parameter 1'' (500). , S Pa=K 1 ・Vmd−K 1 ・G 1 ,S
Pa=K2 ・Vmd-K2 ・G2, SPa=K3
・Vmd-K3 ・G3,SPa=K4 ・V
Calculate md-K4 ・G4 (372, 375, 378
, 381). Comparing this with the current slip rate Sp (3
73,376,379,382), current wheel acceleration Vmd
and the current slip rate SP is ``r pressure reduction'', ■ ``pulse pressure reduction''.
, ■ "Hold", ■ "Pulse pressure increase" or (0) "Pressure increase" is determined, and the determined mode region is set in the register BMRa (371, 374
, 377, 380, 383).

Referring again to FIG. 15a. When CPU II determines the mode, it then executes "output processing J (600). The contents are shown in FIGS. 15e to 15h.

To explain the outline, ■ When it is determined that the pressure is reduced, the solenoid on-off valve 34 is opened using the solenoid on-off valve 33 (15th
h figure). As a result, the electromagnetic on-off valve 33 to the wheel brake 7,
8 of brake oil flows into the reservoir 20 through the electromagnetic on-off valve 44. The brake pressure of the wheel brakes 7 and 8 decreases at a relatively high pick-up speed.

■If it is determined to be "pulse depressurization", 16+msec is considered as "depressurization", and the next 16msec is the solenoid on-off valve 33,
34 are both closed to "hold" and repeat "depressurization" and "hold" (Figure 15g).

As a result, the wheel brake pressure decreases at a lower speed than during the "pressure reduction" described above.

(2) If it is determined to be "hold", the electromagnetic on-off valve 33 and the electromagnetic on-off valve 44 are closed (Fig. 15g).

As a result, the brake oil from the electromagnetic on-off valve 33 to the wheel brakes 7 and 8 is cut off from the mask cylinder 2 and the reservoir 20, and the -55-brake pressure of the wheel brakes 7 and 8 does not change.

■If it is determined to be a "pulse pressure increase", use the initial speed Vpi (the wheel rotation speed when 1 is written to the register FPC), and calculate the pulse period Tpip = a-Vpi" + b-Vpi + c (see Figure 14). ), 6msec is the electromagnetic on-off valve 33
is open and the solenoid on-off valve 44 is closed (pressure increase), and the next (T
pip - 6) msec ((T pipa -
6) "pressure increase" and "hold" are repeated (Fig. 15f).

This causes the brake pressure in the wheel brakes to increase at a relatively low rate.

(O) When it is determined that there is a "sudden pressure increase", the electromagnetic on-off valve 33 is opened and the electromagnetic on-off valve 44 is closed (FIG. 15e).

This causes the brake pressure in the wheel brakes to increase at a relatively high rate. In addition, also in this (0) "sudden pressure increase", using the initial velocity Vpi, the pulse period Tpip = a
-Vpi" + Vpi + c (see Figure 14) and starts the timer T pip. This is (
0) r Rapid pressure increase" is interrupted, or when switching to 56- ■ "Pulse pressure increase", the preceding "pressure increase"
This is to set the interval (period) between this and the subsequent "pressure increase" to be T pip.

Referring to FIGS. 15e to 15h, "Output processing I J
(600) will be explained in detail.

(0) "Control of rapid pressure increase (0)" (Fig. 15e): When the data written to the mode register BMRs indicates rapid pressure increase (0), from step (13g) to (1
Proceeding to step 39), it is checked whether the contents of the previous mode register BMRp also indicate a rapid increase in pressure (0). If not (the previous mode was a different mode), the contents of the decompression flag register BDS are checked (140). The content of BDS is 10.”
In this case, pressure reduction (sudden pressure reduction and pulse pressure reduction) after pressure increase has never been performed (brake oil is not stored in the reservoir 20: this is a normal braking action that does not require anti-skid control). SL3=L (electromagnetic on-off valve 33=open), SL4=L (electromagnetic on-off valve 34=closed)
(the state shown in FIG. 12a) (145).

Then return to the main routine (next brake pressure control IA
: Proceed to 121A).

If the content of BDS is "1", then the content of the pressure increase flag register BIS is checked (141). If the content of the pressure increase flag register BIS is "0", this means that the pressure will be reduced (sudden pressure reduction or pulse pressure reduction) after the brake pedal 1 is depressed, and then the pressure will be increased (sudden pressure reduction or pulse pressure increase). means it is not running. Therefore, the electric motor 19 (pumps 18, 18A) is driven (outputs "1" to MD), and since this pressure increase is the first pressure increase after the pressure reduction, to indicate this, the pressure increase Write "1" to the flag register BIS (142). Then, the pressure increase period Tpip=a-Vpi''+b-Vpi+c is calculated and written to the pressure increase period register Tpip (143).

Vpi is the content of the initial velocity register Vpi, and the FPC
= Wheel speed Vmd when set to 1. Tpi
p is large when the initial velocity Vpip is high. Next, load Tpip into the timer and start the timer (timer Tpi
p start: 144), SL3 = L (electromagnetic on-off valve 33 = open), SL4 = L (electromagnetic on-off valve 34 = closed)
(the state shown in FIG. 12a) (145). Then return to the main routine.

-58- In the check in step (141), the content of the pressure increase flag register BIS was rlJ (pressure increase is being executed after pressure reduction = timer Tpip has started; however, the previous control mode was (not a rapid pressure increase), it is checked whether the timer Tpip has timed out (146), and if it has not timed out, Tpip has not elapsed since the previous pressure increase, so the current pressure increase is performed after that time has elapsed. In order to
: closed), SL4 = L (electromagnetic on-off valve 34: closed) and held (147), and returns to the main routine.

If the timer Tpip has timed out, it means that Tpip has passed since the previous pressure increase, so the timer
Restart Tpip (144) and perform pressure increase (
145) Return to main routine.

Through the above process, pressure reduction (sudden pressure reduction ■ or pulse reduction ■)
is not executed, the rapid pressure increase (0) is executed immediately and continuously for the required time when required. Pumps 1g and 18A are not driven. This is because the electromagnetic on-off valve 34 was closed until then, and the brake oil between the wheel brakes 8 and 9 had never been drained from the electromagnetic on-off valve 33 (it was not stored in the reservoir 20). This is because the brake oil in the brake system from the mask cylinder 2 to the wheel brakes 8 and 9 does not decrease, and the brake pressure is normally applied in conjunction with the mask cylinder discharge pressure (no need for pressure reduction).

For the first pressure increase after pressure reduction has been executed (including rapid pressure increase and pressure increase during pulse pressure increase), pumps 18 and 18A are driven (this is the pulse pressure increase, hold ■, and pulse pressure decrease ■). Otherwise, it is stopped when the brake pressure adjustment is completed (29)), and thereafter, Tpip is calculated and a timer Tpip is started so that the pressure is increased at a cycle equal to or longer than Tpip. Even if a sudden pressure increase or pulse pressure increase is decided again before the timer Tpip times out, it will be held until the time is over, and after the time has passed, if a sudden pressure increase or pulse pressure increase is still necessary. The pressure is increased and timer Tpip is started again.

Note that the rapid pressure increase (0) is continuously performed as "pressure increase: SL3 = L, SL4 = L" while it is determined that it is necessary.
Continue J. In a situation where the pressure suddenly increases (0) continuously, the contents of the mode register 601 register BMRs and the previous mode register BMRp are both 0. At this time, through steps (139) and (140), the process proceeds from (140) to (145), and "pressure increase" is continued. Therefore, "pressure increase" is continuously performed while the rapid pressure increase (0) is determined, and the "pressure increase" period substantially continues while the "rapid increase pressure (0)" is determined.

■ "Control of pulse pressure increase ■" (Fig. 15f): When the data written to the mode register BMRs indicates pulse pressure increase ■, steps (148) to (149)
), it is checked whether the contents of the previous mode register BMRp also indicate pulse pressure increase (■). If not (the previous mode was a different mode), the contents of the decompression flag register BDS are checked (150).

If the content of BDS is “0”, the pressure increase period register Tp
Write the standard cycle (fixed value) Tpips to ip, start the timer Tpip (155), start the timer 6 msec that determines the period of "pressure increase" in the pulse pressure increase (156), and start the electric motor l9. Stop (“0” in MD)
" output), SL3 = L (electromagnetic on-off valve 33: open), S
The pressure is increased by setting L4 = L (electromagnetic on-off valve 34: closed) (157), and the process returns to the main routine.

If the content of BDS is "1", pressure reduction is being performed.

Then, the contents of the pressure increase flag register BIS are checked (152). The contents of the pressure increase flag register BIS is “0”
, this means decompression (sudden decompression or pulse decompression)
This means that no pressure increase (sudden pressure increase or pulse pressure increase) is performed after that. Therefore, this pressure increase is
Since this is the first pressure increase after pressure reduction, rlJ is written in the pressure increase flag register BIS to indicate this (1
53). Then, the pressure increase period Tpip=a−Vpi”+
b-Vpi+c is calculated and written to the pressure increase period register Tpip (154).

Vpi is the content of the initial speed register Vpi, which is the average wheel speed Vmd when the brake pedal 1 is depressed. Tpip is large when the initial velocity Vpi is high. Next, the timer Tpip is started (155), and the timer Tpip is set to 6ms.
Start ec (156), SL:3 = L (
Solenoid on-off valve 3 = open), SL4 = L (Solenoid on-off valve 4 = closed)
(157) Then return to the main routine.

In the check in step (152), the content of the pressure increase flag register BIS was "1" (pressure increase is being executed after pressure reduction = timer Tpip has started; however, the previous control mode was pulse (not pressure increase)
It is checked whether the timer Tpip has timed out (158), and if it has not timed out, Tpip has not elapsed since the previous pressure increase, so in order to increase the current pressure after that elapsed time, SL3 = H. (Solenoid opening/closing valve 33: closed), SL4=L (electromagnetic opening/closing valve 34: closed), hold (159), and return to the main routine. When the timer Tpip has timed out, since Tpip has passed since the previous pressure increase, the timer Tpip is restarted (155), the timer 6 msec is started (156), and the pressure increase is output (157). ), return to the main routine.

Contents of previous mode register BMRp and mode register BM
When the contents of Rs are both 1 (pulse pressure increase), pulse pressure increase has already started and steps (155) to (1
57) is being executed. Therefore, in this case, the process proceeds from step (149) to step (160) to determine whether "pressure increase" is currently being output or "hold" is being output (63) (increase in pulse pressure increase). (press period or hold period) (160). When SL3 is L, pressure is being increased, and when SL3 is H, it is being held.

If the pressure is being increased, it is checked whether the timer 6 msec has timed out in order to see whether the "pressure increase" period of 6II sec has ended (161). If the time has not expired, return to the main routine (
Continuation of "pressure increase"). If the timer 6msec has timed out, set SL3 = H (hold) (162
), return to the main routine.

If the timer Tpip is being held, it is checked whether or not the timer Tpip has timed out (163). If the time has expired, the process proceeds to step 155 to switch to "pressure increase". If the time has not expired, the process returns to the main routine (continuation of hold).

As a result of the above processing, the determination of pulse pressure increase continues.
"Increase pressure" for 6msec, then (Tpip - 6)
Pulse pressure increase is executed by "holding" during mesc and "pressure increase" during the next 6 msec.

Before executing this pulse pressure increase, if "pressure reduction" is not executed, first 6 m at the standard cycle (fixed) Tpip.
Pressure increase for sec, then (Tpip − 6) m
A "hold" is set for sec, and pulse pressure increase is immediately executed by repeating this.

Although "depressurization" is performed before the pulse pressure increase,
When rapid pressure increase or pulse pressure increase is not executed, a period Tpip corresponding to the initial speed Vpi is set, and 6I
“Increase pressure” during IIsec, then (Tpip-6)
Pulse pressure increase is immediately executed by repeating this as a "hold" for msec.

If "pressure reduction" and rapid pressure increase or pulse pressure increase are executed before the pulse pressure increase, the "pressure reduction" is performed until the timer Tpip set for the previous sudden pressure increase or pulse pressure increase times out.
When the time has elapsed, a pulse pressure increase is performed to "increase the pressure" for 6IllSeC and "hold" for the next (Tpip - 6) msec. In other words, “
After performing a pressure reduction (sudden pressure reduction or pulse pressure reduction) and a pressure increase (sudden pressure reduction or pulse pressure increase), a new -65- pulse pressure increase "pressure increase" is equal to the previous "pressure increase". "The timer Tpip started after the timeout expires,
“Hold” is executed until the time is over.

■ "Hold ■" control (Fig. 15g): When the data written to the mode register BMRg is 2 indicating hold ■, the process proceeds from steps (164) to (165), and the contents of the previous mode register BMRp are set to 2. Check whether If it is 2, it has already been "hold" by the previous time.
is running and there is no need to change it, so return to the main routine. The contents of the previous mode register BMRp are 2.
If not, the electric motor 19 is stopped (rOJ is output to MD), hold (SL3=l{, SL4=L) is output (166), and the process returns to the main routine.

■“Pulse pressure reduction ■control” (Fig. 15g): Pulse pressure reduction is “pressure reduction (SL3=H: solenoid on-off valve 33 closed, SL4=H: electromagnetic on-off valve 34 open)” for 16 msec, and then for the next 16 msec. During this time, hold (SL3=H: solenoid on-off valve 33 open, SL4=L: solenoid on-off valve 34 closed) and repeat this.

When the data written to the mode register BMRs is 3 indicating pulse decompression ■, from step (167) to (
16g) and the contents of the previous mode register BMRp are 3.
Check whether If it is not 3, check the contents of the decompression flag register BDS (169) and find that it is ``
If it is 0, it means that decompression has started for the first time, so write 1 to the decompression flag register BDS (17
0), starts the timer 32 msec (171), starts the timer 16 msec (172), stops the electric motor 19 L/ (outputs MD nirOJ), and depressurizes J (SL3=H, SL4=H). (173) and returns to the main routine. When the content of the decompression flag register BDS is "1", step (170) is jumped and steps (171 to 173) are executed. When the content of the previous mode register BMRp is also 3 (pulse decompression), the timer 32msec has already started, and the pulse decompression is set to "decompression" (timer 16IIIsec has not timed out) or "hold" (timer 16
(1 sec timeout) is output, so check which of these is the case (174). If SL4=H, the above-mentioned "decompression J" is in progress, so check whether the timer 16 msec has timed out (175). If it has timed out, SH4 = L and hold (176).
, return to the main routine. If the time has not expired, return to the main routine (with "decompression" still on). SL
= 1 (r hold), timer 32I
It is checked whether or not IIsec has timed out (177), and if it has not timed out, the process returns to the main routine (remains "hold"). When the time is over, timer 32msec and timer 1
Start 6msec (171, 172) and "depressurize"
(173) Return to the main routine.

As a result of the above, when it is determined that "pulse decompression ■J" is determined, "decompression" is first output for 16 msec, and then "depressurization" is output for the next 16 msec.
``Hold'' is output during this period, and the above ``Depressurization'' and ``Hold'' are alternately repeated while the determination of ``Pulse Depressurization ■'' continues.

■ "Control of rapid decompression ■" (Fig. 15h): When the data written to the mode register BMft+ is 4 indicating a sudden decompression of -68 ■, the process proceeds to step (179), and the content of the previous mode register BMRp is (179). The contents of BMRp are also 4
If this is the case, "decompression" is already being output, so the process returns to the main routine. If the content of BMRp is not 4, "1" is written to the pressure reduction flag register BDS and the motor 19 is driven (MD=1) L, and "pressure reduction" is output (8
2) Return to the main routine.

As a result of the above, when it is determined that "sudden pressure reduction ■" is made, "pressure reduction" is continuously outputted while this judgment continues.

In addition, when proceeding to "Brake pressure control IJ (121)", FPC = 1 (wheel brake pressure adjustment is in progress), and the contents of the previous mode register BMRp and current mode register BMRs are both "sudden pressure (0)". In other words, if the "sudden pressure increase (0)" continues for two times (20 msec) so far, then the registers FPC, BDS, BI
Clear S and stop motor 19 (MD=O) L output SL
Set both 3.4 to L and set the electromagnetic on-off valves 33.34 to 12a.
Set the state as shown in the figure (29). This means that the pressure adjustment has been completed. After that, the wheel rotation speed Vm
When s and its acceleration enter the "anti-lock control start region" shown in FIG. 7, the process proceeds to step 23 and subsequent steps.

As explained above, "Brake pressure control I J (211)
For example, when braking is applied on a slippery road surface, if the wheel speed Vpi at that time is high, the wheel brake pressure is "depressurized,""holdJ," and "increased" as shown in Fig. 16a. The period Tpip of "pressure increase" after "pressure reduction" is executed is long corresponding to Vpi. When the wheel speed Vpi is low when the brake is applied, the pressure increase period dp is reduced as shown in Fig. 16b.
ip is a short value corresponding to Vpi.

As mentioned above, the pulse pressure increase is the “pressure increase” of 6IllSeC +
(Tpip + 6)msec Since one cycle is msec, when the initial velocity Vpi is high, the duty is low (6msec/Tpip or 6+msec/Tpi).
When the initial speed Vpi is low, the pressure is increased with high duty.

The CPU 11 performs the "brake pressure control N" explained above.
(1 2 1) is followed by “Brake pressure control IAJ (121
Execute A) (Figure 15a). ``Brake 70 primary pressure control IAJ (121A) is performed in the same way as the above-mentioned ``brake pressure control IJ (1.21)''.
Based on the average velocity Vmsa of R and RL and their acceleration,
It is determined whether or not the pressure adjustment of the wheel brakes 6 and 9 is necessary, and if it is determined that it is necessary, a control mode is determined and the opening and closing of the electromagnetic on-off valves 33A and 34A are controlled accordingly.

In this second embodiment as well, since the initial brake pressure adjustment (the first output process l after rewriting the FPC from O to l) is performed in an appropriate mode corresponding to the road surface μ, over-decreased pressure (insufficient braking) There is a low probability that the brake pressure will be reduced or that the pressure will be insufficiently reduced (over-braking), the wheel brake pressure can be adjusted smoothly, and the vehicle speed (reference speed Vs) can be decelerated quickly.

〔Effect of the invention〕

As described above, according to the present invention, the wheel brake pressure can be adjusted smoothly, and the vehicle speed (reference speed Vs) can be decelerated quickly in the control for suppressing brake slip. In control to suppress acceleration slip, the vehicle speed increases or increases.

-7l-

[Brief explanation of drawings]

FIG. 1a is a block diagram showing a brake pressure control system according to a first embodiment of the present invention. FIG. 1b is an enlarged longitudinal sectional view showing the main parts of the pressure control valve device 3 shown in FIG. 1a. FIG. 2a is a graph showing the relationship between the optimal brake pressure and the coefficient of friction μ of the road surface for the wheels FR, etc. shown in FIG. 1a. FIG. 2b is a graph showing the relationship between the energizing current value and the output pressure of the pressure control valve device 3 shown in FIG. 1b. FIG. 3 is a block diagram showing an outline of the structure of the electronic control device 10 shown in FIG. 1a. FIG. 4 is a flowchart showing an overview of the control operation of the microcomputer l1 shown in FIG. Figure 5 shows the "calculation of reference speed Vs" (4) shown in Figure 4.
FIG. FIG. 6 is a flowchart -72- showing the contents of the rFR map control target pressure calculation J (27) shown in FIG. FIG. 7 is a graph showing a brake pressure control start region determined by the correlation between wheel slip rate and wheel acceleration. FIG. 8 is a time chart showing pressure changes during brake pressure control of the wheels FR etc. shown in FIG. 1a. FIG. 9 is a time chart showing changes in wheel brake pressure when increasing the pressure of the wheel brakes 6, etc. shown in FIG. 1a. FIG. 10 is a plan view showing a condition map for determining pressure increase or decrease, which is referred to in the rFR map control target hydraulic pressure calculation J (27) shown in FIG. FIG. 11 is a longitudinal sectional view showing a modification of the pressure control valve system W3 shown in FIG. 1b. FIG. 12a is a block diagram showing a brake pressure control system according to a second embodiment of the present invention. FIG. 12b is a block diagram showing the configuration of the electronic control device 10 shown in FIG. 12b. FIGS. 13a, 13b, and 13c are graphs showing control mode regions set by CPUl1 shown in FIG. 12b in accordance with detected road surface μ, and FIG. 13a is for low μ. Fig. 13b shows the settings for medium μ, and Fig. 13c shows the settings for high μ. FIG. 14 is a graph showing the pressure increase period determined in response to the axle speed when the CPU II enters brake pressure adjustment in the pulse pressure increase region shown in FIGS. 13a, 13b, and 13c. 15a, 15b, 15c, 15d, 15e, 15f, 15g, and 15h are flowcharts showing the control operation of the CPU 11 shown in FIG. 12b. Figures 16a and 16b represent the CP shown in Figure 12b.
5 is a time chart showing the relationship between UII brake pressure adjustment control and the resulting fluctuations in wheel brake pressure. FIG. 17 is a graph 74 showing an overview of brake pressure adjustment contents with respect to wheel slip rate and wheel acceleration. 1: Brake pedal 2: Brake mask cylinder 3, 3A, 4, 4A: Pressure control valve device 6~
9: Wheel brake FR, FL, RR, RL: Wheel
lO: Electronic control unit 11: CPU
123: Electric coil 12fr, 12
fL, 12rr, 12rL: Wheel rotation synchronous pulse generator 18, 18A: Bomb 19: Motor 2
0.20A: Reservoir 33, 33A, 34
, 34A: Electromagnetic on-off valve CDI 1 Shape of K7 powder ○ Dokito ゜ Flowing 156 Figure 156 JP-A-3 208758 (31) Ri? 1n ■

Claims (3)

[Claims] (1) Brake pressure source; Pressure adjustment means that is located between the brake pressure source and the wheel brake and adjusts the wheel brake pressure; Wheel speed detection means that detects the rotational speed of the axle equipped with the axle brake; The wheel speed detection Calculating means for calculating a reference speed and acceleration of the reference speed based on the wheel rotational speed detected by the means; determining means for determining whether wheel brake pressure adjustment is necessary based on variables including the wheel rotational speed and the reference speed; and Means for estimating a road surface friction coefficient μ from the acceleration at the reference speed when the determining means determines that wheel brake pressure adjustment is necessary; Means for setting a wheel brake pressure adjustment parameter corresponding to the estimated friction coefficient μ; and means for determining the adjustment of the pressure regulating means in accordance with set parameters. (2) Brake pressure source; A pressure control valve device that has an electric coil and is located between the brake pressure source and the wheel brake and applies pressure to the wheel brake corresponding to the current value of the electric coil; energizing means for energizing the electric coil; wheel speed detection means for detecting the rotational speed of the wheel equipped with the wheel brake; a reference speed and an acceleration of the reference speed based on the wheel rotational speed detected by the wheel speed detection means; calculation means for calculating; determining means for determining whether wheel brake pressure adjustment is necessary based on variables including the wheel rotational speed and a reference speed; and the reference speed when the determining means determines that wheel brake pressure adjustment is necessary. A brake pressure control device comprising: a brake pressure control means for calculating a wheel brake pressure corresponding to an acceleration of and instructing the energization means to energize a current value that brings the wheel brake pressure to the wheel brake. (3) Brake pressure source; A switching valve device that is located between the brake pressure source and the wheel brakes and selectively connects the wheel brakes to the high pressure and low pressure of the brake pressure source; The switching valve device is connected to the high pressure and low pressure. Drive means selectively determined for connection; Wheel speed detection means for detecting the rotational speed of the wheel equipped with the wheel brake; Based on the wheel rotational speed detected by the wheel speed detection means, the reference speed and the acceleration of the reference speed are determined. Calculating means for calculating; determining means for determining whether wheel brake pressure adjustment is necessary based on variables including the wheel rotational speed and the reference speed; and determining the reference speed when the determining means determines that wheel brake pressure adjustment is necessary. A brake that determines a parameter for determining a pressure regulation mode in response to acceleration, compares a state quantity indicating the behavior of the wheel with the parameter to determine a pressure regulation mode to be executed, and energizes the drive means in the determined mode. A brake pressure control device comprising: pressure control means;