JPH01226468A - Anti-lock brake controller - Google Patents

Abstract

PURPOSE:To enable coexistence of safety and controllability even on a pavement having different friction coefficients at the right and left side by controlling the rear wheel at same side by means of the control pressure for the front wheel. CONSTITUTION:Two liquid pressure follow valves 14, 14' are provided corresponding to two liquid pressure units 12, 12' One of brake pressures PB, PB' is fed to the liquid pressure unit at the some side and to the liquid pressure follow valve at the opposite side, while the other brake pressure is made symmetrical thereto. Piping is made to feed control pressures PR, PR' at same side to respective Iiquid pressure control valves, where each liquid pressure follow valve comprises a pressure balance section for detecting balanced state of the control pressure in the opposite system and the control pressure of the liquid pressure unit at the same with as the liquid pressure follow valve, a block valve for blocking the flow of brake pressure based on the difference between both pressures and switching to transmit the control pressure to the rear wheel and a bypass for disabling the block valve based on the difference between two brake pressures and forming a bypass in the brake pressure path for the rear wheel. When anti-lock control is made, rear wheel at same side is controlled through the control pressure for the front wheel, and when any one of two brake pressure systems fails, broke operation for the front and rear wheels on a diagonal line in an active side brake pressure system is ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an anti-lock brake control device that includes a hydraulic pressure follow-up valve in the piping system of an automobile brake device that is subjected to anti-lock control.

[Conventional technology]

BACKGROUND ART In recent years, brake systems for automobiles have begun to adopt anti-lock control systems in order to operate the brake system most efficiently in response to changes in the friction coefficient of the road surface. According to this anti-lock control system, the brake pressure in the brake piping is increased, decreased, or maintained regardless of whether the brake is being applied, and the brake release and braking are repeated within a short period of time to obtain the optimal brake braking action. The brakes are controlled.

The piping system of the anti-lock controlled brake system as described above is divided into two systems in order to ensure minimum braking by the other system even if one system fails, considering the safety of the vehicle. In many cases, this division method is IT piping that divides the front wheel system and rear wheel system, JJ piping that divides the right front and rear wheel system and the left front and rear wheel system, or split piping diagonally to the front and rear wheels. Various piping systems such as X piping have been proposed. In particular, the X-piping system has excellent safety in that even if one system fails, braking can be performed using the front and rear wheel brakes on the diagonal lines of the surviving system.

When applying anti-lock control to the brake system, a hydraulic unit is installed in the piping system to adjust the braking pressure from the master cylinder of the brake, regardless of which type of brake system is used. A hydraulic pressure unit is installed independently for each piping system, or a hydraulic pressure unit is installed independently for each piping system of the There are systems in which the control pressure is supplied via a proportional control valve.

The proportional control valve (pressure reducing valve) mentioned above generally reduces the braking pressure in the piping system because the proportion of the braking load on the braking device during braking is large relative to the front wheels and is not necessarily equal between the front and rear wheels. It is used to appropriately distribute the braking load according to the proportion of the brake load. In this proportional control valve, the braking pressure given from the hydraulic unit is a predetermined pressure (break point pressure).
When the pressure exceeds that level, the pressure is reduced at a certain rate to supply pressure to the rear wheels.

Furthermore, in the piping system in which a proportional control valve is installed in the piping of the anti-lock controlled X piping method described above, the front two wheels are each independently anti-lock controlled, so on road surfaces with different friction coefficients on the left and right, the rear two wheels Since the braking pressure on the left and right front wheels differs greatly, the rear wheels on the side with a lower coefficient of friction on the road follow the front wheels with higher braking pressure, and the rear wheels on the side with a higher coefficient of friction on the road follow the front wheels with lower braking pressure. Therefore, there is a problem that the brake balance between the left and right wheels is poor (lack of stability).Therefore, in order to eliminate this problem, a selection valve is installed in front of the proportional control valve in the pipe leading to the rear wheels. Previous 2
When the hydraulic pressures of the two systems are different due to anti-lock control TJ of the wheels, the brake braking pressure for the rear wheels of the lower hydraulic pressure system is selected and the rear wheel brake braking pressure of the higher system side is matched to this. Japanese Patent Application Laid-Open No. 62-13185 discloses a braking device that does not select abnormally low pressure when one system fails and operates the front and rear wheels of the survival system normally.
This is proposed by Publication No. 2.

[Problem to be solved by the invention]

However, if a hydraulic pressure unit is provided independently for each wheel as described above, it is possible to finely control changes in the coefficient of friction from the road surface that occur for each wheel and obtain sufficient performance, but it is economically expensive. This causes an increase in costs.

- Providing a hydraulic unit 7) for each brake piping system is inexpensive, but in addition to the above-mentioned disadvantages, there is also the disadvantage that the stopping distance may be significantly extended depending on the control method.

Furthermore, in the piping system in which a selection valve is provided, stability is excellent if control pressures on the lower pressure side are selected for the hydraulic pressure of the rear wheels, but there is a problem that the stopping distance is also increased.

This invention was made in view of the current state of brake braking technology using conventional anti-lock control, and its purpose is to control the rear wheels on the same side using the control pressure applied to the front wheels. Even on road surfaces with different coefficients of friction on the left and right sides, a hydraulic pressure follow-up valve (liffed anti-lock brake system) that can achieve both stability and braking pressure is installed.
'n equipment.

[Means to solve the problem]

Therefore, as a means for solving the above problems, the present invention calculates the wheel speed, estimated vehicle speed, slip rate, etc. based on the signal from the wheel speed sensor, determines the locked state of the wheel, and generates a brake release and braking command signal. The electronic control circuit that outputs the brake pressure and the braking pressure from the brake master cylinder are two mutually independent braking pressure systems, and these braking pressures can be reduced or increased depending on the output signal from the electronic side' (1) 1 circuit. It is equipped with two hydraulic pressure units that control and supply to the left and right front wheels, and two hydraulic pressure follow-up valves provided corresponding to these two hydraulic pressure units. The braking pressure on the other side is symmetrical to this, and the piping is arranged so that the control pressure on the same side is sent to each hydraulic pressure following valve. The valve includes a pressure balance unit that detects the equilibrium state between the braking pressure of the opposite system supplied from the master cylinder to the rear wheels through the hydraulic pressure follower valve and the control pressure of the hydraulic unit on the same side as the hydraulic pressure follower valve; A pressure equalization section provided in the braking pressure path to the rear wheels blocks the flow of braking pressure through the pressure equalization section, so that the control pressure is transmitted to the rear wheels through the pressure transmission path. and a pressure balance valve that incorporates the shut-off valve and in which the braking pressures of the two systems are introduced and the differential pressure deactivates the shut-off valve to form a bypass path in the path of the braking pressure to the rear wheels. When a pressure difference occurs between the braking pressure and control pressure to the rear wheels during anti-lock control, the hydraulic pressure to the rear wheels is controlled independently by the control pressure to the front wheels, and each hydraulic pressure follower valve is on the same side as the control pressure. In the event of a failure in either the braking pressure or control pressure system, a pressure balance valve is used to deactivate the shutoff valve and a bypass path is used to send braking pressure from the opposite system to the rear wheels. be.

Furthermore, as another means for solving the problem,
One of the two mutually independent braking pressure systems from the master cylinder is sent to the two hydraulic pressure units, and each of the two hydraulic pressure units supplies control pressure controlled to a depressurized or pressurized state to the front wheels by an output signal from the electronic control circuit. The two hydraulic pressure follow-up valves corresponding to the hydraulic pressure unit have one braking pressure system branched into two and sent to each other, and the other braking pressure system branched into two and sent to each, so that each hydraulic pressure follow-up valve is connected to the hydraulic pressure unit. The valves are piped so that the control pressure on the same side is sent, and each hydraulic pressure follower valve has the same braking pressure as the other brake pressure supplied from the master cylinder to the rear wheels through the hydraulic follower valve. A pressure equalization section detects the equilibrium state with the control pressure of the side hydraulic pressure unit, and is provided in the braking pressure path to the rear wheels, and the braking pressure is adjusted via the pressure equalization section by the differential pressure between both pressures. A shutoff valve that shuts off the flow and switches the pressure transmission path so that the control pressure is transmitted to the rear wheels, and a built-in shutoff valve that allows braking pressure from the two systems to be introduced and the differential pressure to disable the shutoff valve. It consists of a pressure balance valve that is actuated to form a bypass path for the braking pressure to the rear wheels.When a pressure difference occurs between the braking pressure to the rear wheels and the control pressure during anti-lock control, the hydraulic pressure to the rear wheels is transferred to the front wheels. When a failure occurs in either one of the braking pressure or control pressure systems, the pressure balance valve deactivates the shutoff valve and the bypass path releases the braking pressure. The system adopted a configuration in which the brake pressure was sent to the rear wheels, and if a failure occurred in one of the other braking pressure systems, only the front wheels were controlled.

[Operation] When the brake is depressed, two mutually independent braking pressures corresponding to the amount of depression are sent to the hydraulic pressure unit and the hydraulic pressure follower valve, respectively. The two braking pressures are in principle of the same magnitude. This braking pressure is sent to the left and right front wheels via the hydraulic pressure unit, and during non-anti-lock control, it passes through the hydraulic pressure unit as is, and during anti-lock control, it is reduced or increased by commands from the electronic control circuit to a predetermined pressure. It is supplied from the hydraulic unit to the front wheels as a controlled pressure.

In the electronic control circuit, when anti-lock control is started, a wheel speed sensor detects the rotational state of the car's wheels, which suddenly decelerate due to the depression of the brake, and converts the signal into a pulse signal that can be manually operated based on the signal. wheel speed, acceleration,
Calculates the reference wheel speed, estimated vehicle speed, acceleration, slip rate, etc., determines the locked state of the wheels based on the calculation results, and issues a pressure reduction command even if the brake is being depressed if the slip rate is excessive. The brake is released after a short period of time, and when the slip rate falls below a predetermined level, a pressurization command is output to return the control pressure to the brake to the pressurized state, the brake is applied, and the brake is released and the brake is applied. is repeated within a short period of time to make the most effective use of the frictional force from the road surface to achieve brake braking. Perform IO.

The braking pressure and control pressure mentioned above are sent to the hydraulic pressure following valve, and the output pressure is sent to the rear wheels to control the braking operation of the rear wheels. There are two methods of piping for the follower valve: 1.
One is the so-called X piping system, and the other is the so-called I+ piping system.

In the first invention which adopts the The braking pressure is sent symmetrically to the hydraulic pressure unit and the hydraulic pressure follower valve on the opposite side, so that the braking pressure is X-piped.

The other braking pressure is sent to the rear wheel on the same side as the one braking pressure via the hydraulic pressure follower valve on the same side. The hydraulic pressure follower valve on the opposite side is symmetrical. Therefore, normal braking is performed during non-antilock control.

During anti-lock control, when the control pressure is reduced, a pressure difference is created between the control pressure and the braking pressure, and this pressure difference moves the pressure equalization section of the hydraulic pressure follower valve, closing the isolation valve and applying braking to the rear wheels. Pressure is cut off. Thereafter, the pressure transmission path is switched so that the control pressure to the front wheels is transmitted to the rear wheels via the pressure equalization section.

If either of the two brake pressure paths (including the control pressure path) fails, the front wheels driven by the failed brake pressure and the diagonally opposite rear wheels become inoperable, but the opposite diagonal Regarding the front and rear wheels located above, the control pressure that should be introduced into the hydraulic pressure follower valve through which the braking pressure goes and the braking pressure applied to the pressure equalization valve are O or abnormally low pressure. a pressure equalization valve is moved by said other braking pressure applied as its internal pressure to inactivate the isolation valve;
A bypass path is formed in this braking pressure path and conducts to the rear wheel side. Therefore, the front and rear wheels on the opposite diagonal lines are braked, ensuring driving safety and steering stability.

In the second invention that employs the IIX piping system, one braking pressure is branched into two and sent to two hydraulic pressure units, thereby providing the braking pressure system with IIX piping.

The braking pressure sent directly to the two hydraulic follow-up valves is equal to the pressure of the control pressure system from the hydraulic unit, since the shutoff valve is opened via the pressure equalizer. It passes through a hydraulic follow-up valve and is sent to the rear wheels. Therefore, normal braking is performed during non-antilock control.

During anti-lock control, the hydraulic pressure follow-up valve itself operates in the same manner as in the first invention, so the rear wheels are each independently controlled B by the control pressure applied to the front wheels.

If a failure occurs in one of the two braking pressure systems, for example, if a failure occurs in one of the brake pressure systems that sends the hydraulic pressure directly to the hydraulic follow-up valve and brakes the rear wheels, The brakes will be inactive, and braking will be applied only to the front wheels. On the other hand, when a failure occurs in the other brake pressure system, the control pressure from the hydraulic unit and the brake pressure to the pressure equalization valve of the hydraulic pressure follower valve become 0 or abnormally low pressure, so the shutoff valve is activated. It is deactivated, a bypass path is formed, and braking pressure is sent to the rear wheels. Therefore, in this case, the front wheel brakes are inactive, and braking is applied only to the rear wheels. However, in either case, at least the front two wheels or the rear two wheels are braked, so even in the event of a failure, driving safety and t
5 Vertical stability is ensured.

〔Example〕

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

FIG. 1 shows a first embodiment of an antilock brake control device 10 according to the present invention. The master cylinder 11 of the brake generates two mutually independent braking pressures Pa and Pa', which are sent to hydraulic units 12 and 12', respectively, where they can be reduced, held, or increased according to commands from the electronic control circuit 13. The precisely controlled control pressures PR, PR' are sent to the brake cylinders 15, 15' of the front wheels. One of the brake pressures P, is also sent to the opposite hydraulic pressure follower valve 14', and the other brake pressure P, / is symmetrical to this, with the same pressure being applied to each hydraulic pressure follower valve 14.14'. The piping is arranged so that the side control pressures '0' P, . 17.17', 18.18' are front and rear wheels WF, R, and W
This is a wheel speed sensor for detecting the rotational state of RR and L. 19.19' is a proportional control valve for making the output pressure of the hydraulic pressure follower valve 14.14' correspond to the actual distribution of braking load to the front and rear wheels.

The hydraulic unit 12 generally consists of a pump, a solenoid valve, a cut-off valve or, instead of a cut-off valve, a flow control π.
There are two methods using valves (not shown). The former is a three-position system in which the braking pressure of the master cylinder is controlled to be reduced, maintained, or increased, and the latter is a two-position system in which the braking pressure of the master cylinder is controlled to be reduced or increased. In this embodiment, either of these methods may be used.

The electronic control circuit 13 includes wheel speed sensors 17.17'18.
Based on the pulse signal from 18', the wheel speed, reference wheel speed, acceleration, estimated vehicle speed, slip rate, etc. are calculated according to the internal program, and if it is determined that the slip rate is excessive as a result of the calculation, the wheel mouth The hydraulic unit 12.12' sends a command signal to reduce and hold the pressure in the direction of releasing the pressure.
When the slip rate decreases below a predetermined standard, a pressurizing signal is applied again to control the wheels in a direction that locks them.

Details of the hydraulic follow-up valve 14,14' are shown in FIG.

This hydraulic pressure follower valve 14 has a braking pressure P of the opposite side system and a control pressure P of the same side as this hydraulic pressure follower valve 14 introduced into the valve main body 141, and a pressure that detects the equilibrium state of both pressures. A balance section 142 and a cut-off valve 143 provided in a path that supplies the flow of braking pressure PB' to the rear wheels to cut off this flow.
It is equipped with The cut-off valve 143 is a coil spring 143
．． and a poppet 143, and a pressure balancing valve 1 to be described later.
48. Poppet 143. is the opening 148. of the pressure equalization valve 148. It is loosely attached to the opening and opens and closes the opening. The inside of the valve body 141 is divided into three chambers 145 and 145 by a partition wall part 144 and a pressure balance part 142.
It is divided into 45c.

The braking pressure PR' is equal to its introduction bow N46. 'From room 145
, and is supplied to the rear wheels from a port 147 via an opening 148 and a chamber 145°.

On the other hand, the control pressure pH is introduced from the port N461 into the chamber 145c and presses the pressure balancing part 142.
2 is provided in a fluid-tight manner and slidably with respect to the cavity forming the chamber 145c by its O-ring 1428. When the pressure balance section 142 moves to the right, its right end surface pushes the rod of the poppet 143b, opening the opening 148c.

In order to supply braking pressure P,' to the rear wheels in this open state, a plurality of grooves (or recesses) 144. is provided.

Further, the pressure equalization valve 148 has the cutoff valve 1 disposed therein.
43 and an O-ring 148 . within the valve body 141 . It is provided in a fluid-tight state and slidably through the. Boat 148. are drilled at positions that match the ports 146'fi, and are positioned relative to the cut-off valve 143 to the valve seats 148'. , valve seat 148 . for pressure equalization valve 148 . ' is provided.

This pressure balancing valve 148 is normally operated by a spring 148. and a braking pressure P on the same side introduced from the boat 149 into another chamber 148° containing this spring.

Pressed by Po N46', and 148. are held in a position where they match.

The anti-lock brake control device 10 of this embodiment configured as described above operates as follows.

First, when anti-lock control is not performed, the braking pressures P8, P, and ' from the master cylinder 11 pass through the hydraulic pressure units 12 and 12' and are applied to the left and right front wheels, and the hydraulic pressure follows. It is also applied to the left and right rear wheels via valves 14, 14'. In the hydraulic pressure follower valve 14, the same braking pressure is applied to the boat 146'8.146. It is introduced from Just before that, if the cutoff valve 143 was closed, the pressure in the chamber 145c would have dropped below the braking pressure, so the pressure in the chamber 145c would have decreased to below the braking pressure. The pressure balancing section 142 is moved to the right in response to the pressure of the poppet 143. is pressed to open the cut-off valve 143. Therefore, the braking pressure P,' is N46'.

Flowing into the room 1451 from the opening 148, the room 145,
It is sent from the boat 147 to the rear wheels through.

During the above operation, the boat 149
A braking pressure P is introduced into the room 148f, and the braking pressure P is
The pressure balancing valve 148 is pushed to the left in the figure by an elastic force of 48 degrees, and the chamber 145.
The braking pressure p introduced into / is the braking pressure P8 of 148f
Although the pressure is the same as that of the pressure balancing valve 14, due to the difference in pressure receiving area, the braking pressure P and the pressing force from the side are large.
8 remains in its normal position as shown. The above operation is exactly the same for the hydraulic pressure follower valve 14'.

Therefore, when anti-lock control is not performed,
The same braking pressure as the front wheels is always sent to the rear wheels, allowing normal braking to be applied to the left and right front and rear wheels.

When anti-lock control is started, if the brake pedal is pressed excessively and the wheels are suddenly locked, the slip rate will increase, and if the electronic control circuit 13 determines that this slip rate is excessive, the hydraulic unit 12 Reduced pressure to .12';
One of the command signals for holding is output, and the hydraulic pressure of the front wheels is controlled to the control pressure P and PII'. This front wheel hydraulic pressure control is performed separately and independently by the left and right hydraulic pressure units 12, 12', so the friction coefficient from the road surface is large for the left and right front wheels (if different, the two control pressures Pa, PR
' are controlled to different pressures. Therefore, when looking at the hydraulic pressure control for one hydraulic pressure unit 12 and the hydraulic pressure follower valve 14,
The control pressure P, from the hydraulic pressure unit 12 is smaller than the braking pressure P,' sent to the boat 146'm of the hydraulic pressure follower valve 14 (,
Therefore, a pressure difference is generated between the left and right sides of the pressure equalization section 142 of the hydraulic pressure follower valve 14, and therefore the pressure equalization section 142 moves to the left.

Then, the cutoff valve 143 is activated by the spring 143. The opening 148c is closed by the urging force. For this reason, the flow of the braking pressure pH' is cut off, and from then on, the pressure in the chamber 145b changes via the pressure balancing section 142 according to the fluctuation of the control pressure P, and therefore the hydraulic pressure on the same side is controlled to the front wheels on the same side. It follows the pressure P. The above operation is exactly the same for the system of the hydraulic pressure unit 12' and the hydraulic pressure follower valve 14'.

Next, the operation when a failure occurs in either the left or right braking pressure or control pressure piping of the brake piping system will be described.

Assume now that a failure has occurred in the piping for braking pressure P3 and control pressure P7 in the left side system. In this case, even if there is a failure in the control pressure piping, the braking pressure PIl will be O or an abnormally low pressure. Therefore, even if the hydraulic pressure unit 12' and the hydraulic pressure follower valve 14' in the right side system are normal, the braking pressure P is not sent normally, so the front left wheel WFL and the rear right wheel WR11 cannot be braked. I can't.

However, as long as the left hydraulic pressure follow-up valve 14 is normal, the braking pressure p, / of the right system is sent to the left rear wheel WRL via the hydraulic pressure follow-up valve 14. In this case, the control pressures p and t of the hydraulic pressure follower valve 14 also become 0 or an abnormally low pressure, so the pressure balance section 142 moves to the left, and the cut-off valve 143 opens the opening 144. Close. Therefore, the normal flow path of the braking pressure P,' including the cut-off valve 143 is cut off.

Therefore, the pressure equalizing valve 148 is pushed to the right by the braking pressure P,'. At this time, since the braking pressure Pg flowing from the boat 149 is from the left side system, it is also O or abnormally low pressure, so the pressure balance valve 148 moves to the right, and the left end surface of the lip seal 148° touches the partition wall 144. away from the surface and a gap is created between them. Additionally, the pressure balance valve 148
As shown in the figure, the left end is formed into a small diameter shape with different diameters, and this small diameter portion is loosely fitted into the opening of the partition wall portion 144 with a predetermined gap. Therefore, due to the above two gaps, the braking pressure P,
' is formed, through which the braking pressure PB' flows to the chamber 145. and is sent to the rear wheels.

In this way, even if a failure occurs in the piping for the braking pressure P, l of the left system and the control pressure PR, the braking pressure P, ' of the right system can brake the left rear wheel via the hydraulic pressure follower valve 14. Therefore, the right front wheel and left rear wheel can be braked. This is exactly the same when a defect occurs in the right side system.

Therefore, if a failure occurs in the braking pressure or control pressure piping on either the left or right side, complete braking cannot be achieved, but the minimum braking action can be ensured on either front or rear wheel on the diagonal, and the braking Although the distance is longer than in the normal case, the stability and safety of the vehicle body can be achieved.

FIG. 3 shows a modified embodiment of the hydraulic pressure follower valve 14 of FIG.

This valve differs only in that the cutoff valve 143' is replaced with a ball type cutoff valve instead of a poppet type one.

In this case the cut-off valve 143' spring 143. and a ball 143', and a rod 142' for opening and closing the opening 148c with this cut-off valve 143' is provided at the end of the pressure balancing section 142.

The effect is the same as in the case of Figure 2.

FIG. 4 is a partial system diagram showing the parts of the hydraulic piping that are changed when the hydraulic pressure follow-up valve 14 of FIG. 5 is applied to the first port anti-lock brake control device 10. Basically, it is the same as the case in Fig. 1, but the braking pressure P3' of the opposite system is
The difference is that the brake pressure P is introduced in two branches, and the braking pressure P on the same side is introduced at the left end position.

FIG. 5 shows a second variant embodiment of the hydraulic pressure follower valve 14. In this embodiment, the pressure equalizer 142'' consists of two pistons 142'', connected by a rotor 142'' and a rod 142''. penetrates the partition wall portion 144'', and pistons 142'' are attached to both ends thereof. The cut-off valve 143# is of the ball type as in the case of FIG. 3, and is provided on a partition wall 144''.The partition wall 144'' is provided at the center of the valve body 141''.

Furthermore, the braking pressure is introduced through boats 149'', 149'' for pressurizing the two pistons 142'' from the outside with braking pressures Pm and Pa', respectively. Other members corresponding to those shown in FIG. 2 are designated by the same reference numerals with a ``" added thereto.

Under normal conditions, when there is no failure in any of the piping systems,
Since the two braking pressures P8 and P++' are basically the same pressure, when they act on the two pistons, they cancel each other out and have no effect. When the brake is depressed in this state, during non-anti-lock control, the pressure balance section 142'' shifts to the right from the neutral position shown, and the rod 142'' attached to the right piston 142''. does not press the cut-off valve 143'' and the opening 144'' is closed, then room 1
45", the pressure in the left piston 142" is reduced to below a pressure equal to the braking pressure introduced into the chamber 145" from 146"R.

Pressing the rod 142'' to the left causes the pressure equalizer 142'' to move to the left and return to the neutral position shown.

pushes the cut-off valve 143'' and opens the opening 144''.

is opened, and the braking pressure p, L flows into the chamber 145'' through the opening 144'' and into the other chamber 145.
”.

The pressure is balanced with the pressure inside and maintains the pressure balance section 142'' in a neutral position, and is sent to the rear wheels through the boat 147''.

In this way, normal braking operation is performed.

During anti-lock control, when the control pressure P++ is controlled to a pressure state of decreasing and maintaining, the pressure becomes lower than the braking pressure P%. Therefore, the pressure equalization section 142'' moves to the right due to the differential pressure, and the cut-off valve 143'' opens the opening 144''.
, is closed. Thereafter, fluctuations in the controlled pressure P are transmitted to the hydraulic pressure to the rear wheels via the pressure equalization section 142'', thereby switching the pressure transmission path.

If the left system of the two piping systems for braking pressure and control pressure fails, the braking pressure P for the hydraulic pressure follower valve 14 in FIG.
3. Control pressure PR becomes 0 or abnormally low pressure. For this reason, the right piston 142'' with respect to the pressure balance section 142''
, a braking pressure P,' is applied from the inner and outer surfaces of the rod, and the pressure receiving area is the rod 142''.

The difference due to the inner side is small, so the pressure equalization part 142''
moves greatly to the left and opens the cut-off valve 143'',
The braking pressures p, l are sent to the rear wheels through the cut-off valve 143''.When the right system fails, the situation is opposite to the above.

In the end, in the case of the embodiment shown in FIG. 5, as in the embodiment shown in FIG. The ring will survive.

FIG. 6 shows a schematic system diagram of the anti-lock brake control device 10'' of the third embodiment. As shown in the figure, in this embodiment, two mutually independent braking pressure systems Pg, Ps' is applied to the brake cylinders 15,15' of the left and right front wheels WF□ through two hydraulic pressure units 12,12', and the other side is connected to the left and right brake cylinders 15,15' through two hydraulic pressure follower valves 14. This differs from the first embodiment in that it is supplied to the brake cylinders 16, 16' of the rear wheels WRt, ++, and is piped to form a so-called II pipe.

Braking pressure PR to the front wheels is provided by two hydraulic units 12.12'
At the same time, two hydraulic pressure follow-up valves 14 are installed to prevent failures.
．． 14' is also branched into two on the way, and the other braking pressure system P,' is also branched into two on the way.
14 and 14' respectively. In the illustrated example, the hydraulic pressure follower valve 14,14' is of the type shown in FIG. 2, but it is of course possible to use the type shown in FIG. 3 or 5. However, when using the type shown in Fig. 5, as in the embodiment shown in Fig. 4,
The braking pressure piping must be slightly different.

Other members having the same functions as those in FIG. 1 are given the same reference numerals.

The actions during non-antilock control and antilock control are basically the same as those shown in Figure 1, and during antilock control, the hydraulic pressure to the rear wheels is independent of the left and right by the control pressures PR and Pa' to the front wheels. are controlled respectively. However, braking pressure P6
, P,', and when a failure occurs in any of the control pressures P, , P', the operation is slightly different from that shown in FIG. 1. That is,
If either the braking pressure P8 or the control pressure P of the left side system fails, the pressure becomes 0 or an abnormally low pressure. Therefore, the front two wheels cannot be braked, but the other braking pressure P,'
is sent to the two rear wheels through the hydraulic follow-up valves 14, 14', so that the two rear wheels can be braked. On the other hand, if either of the braking pressures P,' or the control pressures P, J of the right side system fails, the two rear wheels will be unable to brake, and only the two front wheels will be braked. Therefore, in such a failure, the front two wheels or the rear two wheels
Since the wheels are at least brakeable, a minimum braking capacity is ensured. Furthermore, it is clear that the above-mentioned effect can be obtained in exactly the same way when the hydraulic pressure following valves shown in FIGS. 3 and 5 are employed.

〔effect〕

As explained in detail above, in the present invention, two hydraulic units are used for an anti-lock brake control device that independently anti-lock controls the brakes of the two front wheels via an electronic control circuit and two hydraulic units. During anti-lock control, the control pressure applied to the front wheels also controls the rear wheels on the same side, so that if a failure occurs in either of the two braking pressure systems, Braking of the diagonally diagonal front and rear wheels of the surviving braking pressure system, or two front wheels or two rear wheels is ensured. Therefore, anti-lock control of rear wheel braking can be achieved by providing a hydraulic pressure follow-up valve with a simple structure, which has the advantage of making the brake system economical and ensuring safety.

[Brief explanation of the drawing]

Figure 1 is a schematic system diagram of the first embodiment of the anti-lock brake control device, Figure 2 is a detailed diagram of the hydraulic pressure follower valve, and Figure 3 is a modified example of the hydraulic pressure follower valve in Figure 2. Figure 4 is a partial piping system diagram when using the hydraulic pressure follower valve shown in Figure 5, Figure 5 is yet another modified embodiment of the hydraulic pressure follower valve, and Figure 6 is the anti-lock brake of the second embodiment. It is a schematic system diagram of a control device. 10.10', 10''...Anti-lock brake control device, 11...Master cylinder, 12.12...i pressure-1-soto, 13...
...Electronic control circuit, 14.14'...Hydraulic pressure follow-up valve, 19.19'.
...proportional control valve, 142 ... pressure balance section, 143 ... cutoff valve, 148 ...
・Pressure balance valve. Patent applicant: Sumitomo Electric Industries, Ltd. Agent: Kama 1) Text: Figure 1, Figure 3, Figure 84'T-4-G::;S Figure 6

Claims (7)

[Claims] (1) An electronic control circuit that calculates wheel speed, estimated vehicle speed, slip rate, etc. based on signals from wheel speed sensors, determines the locked state of the wheels, and outputs brake release and braking command signals, and a brake master. Braking pressure from the cylinder is 2
These two hydraulic pressure units have two mutually independent braking pressure systems, and each brake pressure is controlled to a reduced or increased state by an output signal from an electronic control circuit and then supplied to the left and right front wheels. two hydraulic pressure follow-up valves provided correspondingly to the brake pressure, one of the braking pressures is sent to the hydraulic pressure unit on the same side and also to the hydraulic pressure follow-up valve on the opposite side,
The braking pressure on the other side is symmetrical to this, and the piping is arranged so that the control pressure on the same side is sent to each hydraulic pressure follower valve, and each hydraulic pressure follower valve is supplied from the master cylinder to the rear wheel through the hydraulic pressure follower valve. a pressure equalization section that detects the equilibrium state between the braking pressure of the opposite side system and the control pressure of the hydraulic pressure unit on the same side as the hydraulic pressure follower valve; A shutoff valve that shuts off the flow of braking pressure through a pressure equalization section based on the differential pressure between the two pressures and switches the pressure transmission path so that the control pressure is transmitted to the rear wheels, and a shutoff valve that incorporates the shutoff valve and connects the two systems The brake pressure is introduced into the valve, and the differential pressure disables the shutoff valve to form a bypass path for the brake pressure to the rear wheels. When a differential pressure occurs between the two, the hydraulic pressure to the rear wheels is controlled independently by the control pressure to the front wheels, and if a failure occurs in either the braking pressure or control pressure system on the same side as each hydraulic pressure follower valve. An anti-lock brake control device configured to disable a shutoff valve using a pressure balance valve and send braking pressure from the opposite system to the rear wheels via a bypass path. (2) One of the two mutually independent braking pressure systems from the master cylinder is sent to the two hydraulic pressure units, and the control pressure is controlled to be reduced or increased depending on the output signal from the electronic control circuit, and each is supplied to the front wheels. The two hydraulic pressure following valves corresponding to the two hydraulic pressure units have one braking pressure system branched into two and sent to the other, and the other braking pressure system branched into two and sent to each of them. , each hydraulic pressure follower valve is piped to send the same control pressure, and each hydraulic pressure follower valve receives the other braking pressure and its fluid supplied from the master cylinder to the rear wheels through the hydraulic pressure follower valve. A pressure equalization section that detects the equilibrium state with the control pressure of the hydraulic pressure unit on the same side as the pressure follower valve, and a pressure equalization section that is provided in the braking pressure path to the rear wheel and operates based on the differential pressure between the two pressures to the pressure equalization section. a shutoff valve that shuts off the flow of braking pressure and switches the pressure transmission path so that the control pressure is transmitted to the rear wheels; It consists of a pressure balance valve that deactivates the shutoff valve and forms a bypass path for the braking pressure to the rear wheels.When a pressure difference occurs between the braking pressure to the rear wheels and the control pressure during anti-lock control, the pressure to the rear wheels is reduced. The hydraulic pressure is controlled independently by the control pressure to the front wheels, and if a failure occurs in either of the braking pressure or control pressure systems, the pressure balance valve deactivates the shutoff valve and a bypass path is activated. The anti-lock brake control device according to claim 1, wherein the braking pressure is sent to the rear wheels, and when a failure occurs in one of the other braking pressure systems, only the front wheels are controlled. . (3) Claim 1 characterized in that the shutoff valve of the hydraulic pressure follower valve is a cutoff valve comprising a spring means and a poppet.
Or the anti-lock brake control device according to 2. (4) The cutoff valve of the hydraulic pressure follower valve is a cutoff valve consisting of a spring means and a ball, and a rod for opening and closing this valve is provided in the pressure balance section, and this rod is loosely fitted into the pressure balance valve. The anti-lock brake control device according to claim 1 or 2, wherein the anti-lock brake control device is inserted through the cut-off valve to open and close the cut-off valve. (5) The braking pressure on the same side that is sent to the hydraulic pressure follower valve on the opposite side is branched into two parts on the way and is supplied to the hydraulic pressure follower valve,
The braking pressure system on the opposite side is also symmetrical with this, and each hydraulic pressure follower valve has the brake pressure of the opposite system supplied from the master cylinder to the rear wheel through the hydraulic pressure follower valve, and the fluid on the same side as the hydraulic pressure follower valve. a pressure balance section that detects an equilibrium state with the control pressure of the pressure unit;
The flow of braking pressure is blocked via the pressure equalization part due to the differential pressure between the two pressures in a pressure equalization part provided in the brake pressure path to the rear wheels, and the control pressure is transmitted to the rear wheels through the pressure transmission path. A shutoff valve is provided at both outer ends of the pressure equalization section, and the brake pressure on the same side is supplied to the side where the control pressure is introduced, and the brake pressure on the branched side is switched on the side where the opposite brake pressure is introduced. When the brake pressure on the opposite side is increased, and a pressure difference occurs between the brake pressure to the rear wheels and the control pressure during anti-lock control, the hydraulic pressure to the rear wheels is independently controlled by the control pressure to the front wheels, and each hydraulic pressure is increased. When a failure occurs in either the braking pressure or control pressure system on the same side as the follower valve, the braking pressure from the opposite side is branched to the pressure balancing valve and introduced, opening the shutoff valve via the pressure balancing section. 5. The anti-lock brake control device according to claim 1, wherein the braking pressure from the opposite system is sent to the rear wheels. (6) One of the braking pressure systems is branched into two and supplied to the two hydraulic pressure follower valves. Among the brake pressure systems, the system that is sent to the other hydraulic pressure follower valve is further branched into two and the brake pressure system is The other braking pressure is branched into two and supplied to the two hydraulic pressure following valves. Among the braking pressure systems, the system that is sent to one of the hydraulic pressure following valves is further branched into two. Each hydraulic pressure follower valve controls the other braking pressure supplied from the master cylinder to the rear wheels through the hydraulic pressure follower valve and the hydraulic unit on the same side as the hydraulic pressure follower valve. A pressure equalization section is provided in the braking pressure path to the rear wheels to detect the equilibrium state with the brake pressure. It is equipped with a shutoff valve that switches the transmission path so that the control pressure is transmitted to the rear wheels, and the brake pressure on the same side is applied to the pressure equalization part at both outer ends thereof, and on the side where the control pressure is introduced. On the side where the other braking pressure is introduced, the braking pressure is further divided into two parts and one of them is pressurized, and when a differential pressure occurs between the braking pressure to the rear wheels and the control pressure during anti-lock control, the pressure to the rear wheels is increased. The hydraulic pressure is controlled independently by the control pressure to the front wheels, and when a failure occurs in either one of the braking pressure or control pressure systems, the pressure is increased by the braking pressure that is branched to the pressure equalization section and introduced. The shutoff valve is opened via the balance section to send the braking pressure of the other system to the rear wheels, and when a failure occurs in either of the other braking pressure systems, the one braking system is used to transfer the braking pressure to the front wheels. 3. The anti-lock brake control device according to claim 2, wherein the anti-lock brake control device controls only the anti-lock brake control device. (7) A proportional control valve is provided between each of the hydraulic pressure follower valves and the rear wheel, and when the output pressure of the hydraulic pressure follower valve exceeds a certain level, the pressure is reduced by the proportional control valve. The anti-lock brake control device according to any one of claims 1 to 6.