JPH0775978B2 - Anti-lock brake controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antilock brake control device having a hydraulic pressure follow-up valve in a piping system of an automobile brake device under antilock control.

[Conventional technology]

2. Description of the Related Art Recently, as a brake device for automobiles, an anti-lock control system has been adopted in order to operate the brake device most efficiently in response to a change in a friction coefficient of a traveling road surface. According to this anti-lock control method, the brake pressure in the brake pipe is increased, reduced, or maintained regardless of the braking condition, and the brake is released.
The braking is controlled so that the braking is repeated within a short time to obtain the optimum braking operation.

The anti-lock controlled brake system piping system is generally divided into two systems in order to ensure minimum braking by the other system even if one system fails in consideration of the safety of the vehicle. There are many methods of this division, II piping that divides into the front wheel system and the rear wheel system, JJ piping that divides into the right front wheel system and the left front wheel system, or X piping that divides the front and rear wheels diagonally. Various piping systems have been proposed. In particular, the X piping system is excellent in safety because even if one system fails, it can be braked by the front and rear wheel brakes on the diagonal line of the surviving system.

In the case of antilock control of the brake device, a hydraulic unit for adjusting the braking pressure from the master cylinder of the brake is provided in the piping system for any of the above systems, but this hydraulic unit is provided for each wheel individually. A hydraulic pressure unit is installed independently for each of the X-pipe type piping system, and is usually controlled for the front wheels, and the control pressure adjusted by this hydraulic unit is applied to the rear wheels. Are supplied through a proportional control valve.

In the above proportional control valve (pressure reducing valve), the ratio of the braking load applied to the braking device during braking is generally large relative to the front wheels and not necessarily equal to the front and rear wheels. It is used for proper distribution according to the load ratio. With this proportional control valve, the braking pressure applied from the hydraulic unit is a predetermined pressure (break pressure).
When the above is reached, the pressure of the rear wheels is reduced by reducing the pressure at a constant rate.

Further, in the piping system in which the proportional control valve is provided in the anti-lock-controlled X piping system, the front two wheels are independently anti-lock controlled, and therefore the rear two wheels are used on the road surface having different left and right friction coefficients. Regarding, since the braking pressures on the left and right of the front wheels are greatly different, the rear wheels on the low friction coefficient side of the road follow the braking pressure on the front wheels on the high friction coefficient side of the road,
The rear wheels on the side with a high friction coefficient on the road surface follow the braking pressure of the front wheels on the side with a low friction coefficient on the road surface, and there is a disadvantage that the left and right wheels have poor brake balance and lack stability.

Therefore, in order to eliminate such inconvenience, when a selection valve is provided in front of the proportional control valve in the pipe leading to the rear wheels and the hydraulic pressures of the two systems generated by antilock control of the front two wheels are different, Select a brake braking pressure to the rear wheels of the low hydraulic system so that the rear wheel brake starting pressure on the high system side matches this, and when the system fails, the abnormal low pressure is not selected and the survival system side Japanese Patent Application Laid-Open No. 62-131852 proposes a brake device that allows normal operation of front and rear wheels.

[Problems to be Solved by the Invention]

However, when the hydraulic unit is provided independently for each wheel as described above, fine control can be performed in response to changes in the friction coefficient from the road surface that occur for each wheel, but sufficient performance can be obtained, but it is expensive in terms of economy. This will increase the cost.

When a hydraulic unit is provided for each braking pipe system, it is inexpensive, but in addition to the above-mentioned inconvenience, there is a drawback that the braking distance is significantly extended depending on the control method.

Further, in the piping system in which the selection valve is provided, stability is excellent when the control pressures on the low pressure side are mutually selected for the hydraulic pressures of the rear wheels, but there is a problem that the control distance is slightly extended.

The present invention has been made in view of the current state of the conventional braking technology by antilock control, and its purpose is to control the rear wheels on the same side by using the control pressure to the front wheels. It is an object of the present invention to provide an anti-lock brake control device equipped with a hydraulic pressure follow-up valve that can achieve both stability and braking performance that can shorten the braking distance even on roads having different friction coefficients.

[Means for Solving the Problems]

Therefore, in the present invention as a means for solving the above problems, the wheel speed, the vehicle estimated speed, the slip, etc. are calculated based on the signal from the wheel speed sensor to determine the wheel lock state to determine the brake release and braking command signals. And the braking pressure from the master cylinder of the brake are set as two mutually independent braking pressure systems, and these braking pressures are controlled by the output signals from the electronic control circuit to the depressurized or pressurized state, respectively. Braking through the two hydraulic units that are supplied to the front wheels of the vehicle and the pressure balancing unit that detects the equilibrium state of both pressures by introducing the braking pressure from the master cylinder and the control pressure from the hydraulic unit. A shut-off valve that shuts off the flow of pressure and switches the pressure transmission path so that the control pressure is transmitted to the rear wheels, and a braking pressure of the two systems that incorporates the shut-off valve is introduced. When one of the braking pressure systems fails, the pressure difference causes the shut-off valve to be inoperative and sends the braking pressure to the rear wheels of the survival side system. The left front wheel system and the right front wheel system are provided with a pair of hydraulic pressure follow-up valves, respectively, and one of the braking pressures is sent to the hydraulic pressure unit on the same side and also to the shut-off valve of the hydraulic pressure follower valve on the other side, and the other side. The braking pressure of is symmetric with this, and piping to send the braking pressure on the same side as the front wheels to each hydraulic pressure follow valve,
When a pressure difference occurs between the braking pressure and control pressure to the rear wheels during antilock control, the hydraulic pressure to the rear wheels is controlled independently by the control pressure to the front wheels on the same side, and the same side as each hydraulic pressure follow-up valve. When a failure occurs in the braking pressure system, the antilock brake control device is configured to control the front and rear wheels of the other diagonal braking pressure system that passes through the hydraulic pressure follow-up valve. is there.

According to the first aspect of the present invention, one of two braking pressure systems from the master cylinder is provided to the two hydraulic units instead of the piping for sending the braking pressure and the control pressure to the hydraulic unit and the hydraulic pressure follow-up valve. Is sent to each of the left and right front wheels, and the braking pressure of one of them is branched into two to the two hydraulic pressure follow-up valves. The other braking pressure is branched into two and sent directly to the cutoff valve path of the two hydraulic pressure follow-up valves. Piping is made so that the control pressure on the same side as the front wheels is sent to each hydraulic pressure follow-up valve. Then
When a failure occurs in the braking pressure system on the same side as each hydraulic pressure follow-up valve, only the left and right front wheels or only the left and right rear wheels may be braked.

In the first or second aspect of the invention, the shutoff valve of the hydraulic pressure follow-up valve may be a cutoff valve including spring means and a poppet.

Alternatively, the shutoff valve of the hydraulic pressure follow-up valve is a cut-off valve composed of spring means and a ball, and a rod for opening and closing the valve is provided in the pressure balancing portion, and the rod is inserted into the pressure balancing valve in a loose fit manner. At least, the cutoff valve may be opened and closed.

Further, a pressure balancing valve of another type can be used in place of the hydraulic pressure follow-up valve. In that case, the hydraulic pressure follow-up valve is provided with a partition wall portion provided in the valve main body in the first invention. A pressure balance portion provided at both ends of a rod penetrating through the valve and the shut-off valve provided in the partition wall portion. The pressure balance portion is introduced to the outside of the two systems and to the inside thereof. The balance between the control pressure and the other braking pressure introduced via the shutoff valve is detected, and the shutoff valve is opened by the rod attached to the pressure balance section when the braking pressure path fails, and the braking pressure on the survival side to the rear wheel is detected. Is configured to be sent to the hydraulic pressure follow-up valve, and the other brake pressure path is branched corresponding to the hydraulic pressure follow-up valve to be sent to one hydraulic pressure follow-up valve. Connect to the path of the shutoff valve, and use a pipe symmetrical to the other hydraulic pressure follow-up valve. It can be.

Alternatively, in the second aspect of the invention, the hydraulic pressure follow-up valve includes a pressure balancing portion provided at both ends of a rod penetrating a partition wall provided in the valve body, and the shutoff valve provided in the partition wall. , The pressure balance section detects the balance of the braking pressures of the two systems introduced on the outside, the control pressure introduced on the inside and the balance of the other braking pressure introduced via the shutoff valve, and detects the braking pressure path. In the event of a failure, the rod attached to the pressure balance unit opens the shutoff valve to send the braking pressure on the survival side to the rear wheels.The other braking pressure is branched according to this hydraulic pressure follow valve. 2
Two additional routes for each hydraulic pressure follow valve to the shutoff valve
It may be branched into two and one of the shutoff valves may be connected to the other of the pressure balancing portions.

And in any of the above-mentioned first to sixth inventions,
It is preferable that a proportional control valve is provided between each of the hydraulic pressure follow-up valves and the rear wheels, and when the output pressure of the hydraulic pressure follow-up valve becomes a certain value or more, it is reduced by the proportional control valve.

[Action]

In any of the antilock control devices of the first and second aspects of the invention configured as described above, the braking pressure from the master cylinder is supplied to the front wheels via the hydraulic unit and the hydraulic pressure follow-up valve to the rear wheels. Have been sent through. Therefore, since the hydraulic pressure unit and the hydraulic pressure follow-up valve both pass the braking pressure during non-antilock control, the braking pressure due to the brake pedal is sent to the front wheels and the rear wheels as it is, and the normal brake braking action is performed. To do.

When the antilock control is started, the wheel speed based on the pulse signal from the wheel speed sensor in the electronic control circuit,
Acceleration, reference wheel speed, vehicle estimated speed, slip ratio, etc. are calculated, and if it is determined that the slip ratio is excessive as a result, a command for pressure reduction or holding is output to the hydraulic unit. When the slip ratio is restored while the control pressure to the brake cylinders of the front wheels is reduced or held, the acceleration command again causes the pressurization state, and these operations are repeated within a short time.

In this case, in both the first and second aspects, the command from the electronic control circuit is independently output to the left and right hydraulic units. Therefore, when the road surface friction coefficient is greatly different between the left and right front wheels, for example, the left front wheel side has a small friction coefficient, it easily slips, and the right front wheel side has a large friction coefficient. Then, the pressurizing command is output.

On the other hand, the hydraulic pressure to the rear wheels is given through the hydraulic pressure follow-up valve, but in both the first and second inventions, the control pressure on the driven side is sent to the hydraulic pressure follow-up valve on the same side as the front wheel. While the control pressure to the front wheels is being reduced and held in either the left or right system, a differential pressure occurs between the sex phase and the control pressure introduced in the hydraulic pressure follow-up valve. The shutoff valve is closed via the pressure balancing section, and the pressure transmission path is switched to the path through which the control pressure is transmitted to the rear wheel via the pressure balancing section. Therefore, after that, the hydraulic pressure to the rear wheels on the same side is independently controlled according to the fluctuation of the control pressure to the left or right front wheel.

With such control, when the friction coefficient on the left front wheel side is small as in the above example, the rear wheel on the same side is also tracked by the reduced control pressure to the left front wheel. The front and rear wheels are braked most effectively.

On the other hand, if the front wheels of the right system are pressure-controlled, the rear wheels on the same side are also pressure-controlled, so that the right system is also braked most effectively for the road surface condition. For this reason, the front and rear wheels of the left and right systems are optimally brake-braked according to the conditions of the respective road surfaces, so that stability is ensured and braking distance is improved at the same time as the conventional example using the selection valve described above. Is also the shortest.

It should be noted that the first and second inventions are different only in the introduction route of the braking pressure to the hydraulic unit and the hydraulic pressure follow-up valve, and have substantially the same operation.

Next, when either of the two braking pressure paths (including the control pressure path) fails, in the first invention, the front wheels driven by the failed braking pressure and the rear wheels diagonally opposite thereto are inoperative. However, for the front wheel and the rear wheel on the opposite diagonal line, the control pressure to be introduced in the hydraulic pressure follow-up valve through which the braking pressure passes and the braking pressure of the failure system added to the pressure balance valve are It becomes 0 or abnormally low pressure.

Therefore, the pressure balance valve is moved by the other braking pressure applied as its internal pressure to deactivate the shut-off valve, and a bypass path is formed in this braking pressure path so that it is conducted to the rear wheel side. Therefore, the front wheels and the rear wheels, which are diagonally opposite to each other, are brake-braked, and at least only the braking force is secured.

In the second aspect of the invention, when a failure occurs in either of the two braking pressure systems, the failure occurs in, for example, one of the braking pressure systems that are directly sent to the hydraulic pressure follow valve to brake the rear wheels. If this occurs, the brakes on the rear wheels will be inoperative, and the front wheels will be the only brakes. On the other hand, when a failure occurs in the other braking pressure system, the control pressure from the hydraulic pressure unit and the braking pressure to the pressure balance valve of the hydraulic pressure follow-up valve become 0 or abnormally low pressure, so that the shutoff valve operates. It is deactivated and a bypass is formed, and braking pressure is sent to the rear wheels. Therefore, in this case, the braking of the front wheels becomes inoperative, and the braking is performed only by the rear wheels. However, in either case, at least the front two wheels or the rear two wheels are brake-braked, so that the braking force is secured even in the event of a failure.

In the third invention, a cutoff valve composed of spring means and a poppet is used as a shutoff valve, and a cutoff valve composed of spring means and a ball is used in the fourth life. Therefore, when any of the cutoff valves is applied to the first or second invention, it acts as a shutoff valve in the hydraulic pressure follow valve.

A fifth aspect of the invention is a case where different types of hydraulic pressure follow-up valves are applied to the first aspect of the invention. This hydraulic pressure follow-up valve is the same as that of the first aspect of the invention in terms of action, although the type is different. Therefore, the operation during non-antilock control, antilock control, or failure is the same as that of the first invention.

A sixth invention is a case where the hydraulic pressure follow-up valve of the fifth invention is applied to the second invention. Therefore, the operation is the same as that of the second invention.

When the proportional control valve is provided in the seventh invention, the braking pressure or the control pressure to the rear wheels is transmitted to the rear wheels after being slightly reduced from the hydraulic pressure to the front wheels in the pressure range of a predetermined value or more, and then to the front and rear wheels. The brake will be applied according to the load ratio of.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an antilock brake control device according to the present invention.
Figure 10 shows a schematic block diagram of ten embodiments.

Braking pressure P _B , P _B ′ generated in the master cylinder 11 of the brake
Is sent to the hydraulic unit 12, 12 ', where the electronic control circuit
In accordance with the command of 13, the control pressures P _R and P _R ′ controlled to either depressurize, hold or pressurize the front wheel brake cylinders 15 and 15
Sent to.

The braking pressures P _B and P _B ′ control pressures P _R and P _R ′ are hydraulic pressure follow valves 14, 1
The other braking pressure P _B ′ is also symmetrical to this (so-called X piping), and each hydraulic pressure follow-up valve 14, 14 ′ has a control pressure P _R , P on the same side as the front wheels. 'plumbed so is sent, the hydraulic follow-up valve output pressure at the rear wheel of the same side as the front wheel brake cylinders 16, 16' _R is braking.

17, 17 ', 18, 18' is a wheel speed sensor for detecting the front and rear wheels _{WF R, L, WR R,} L, the rotational state of the. 19, 19 '
Is a proportional control valve for making the output pressure of the hydraulic pressure follow-up valves 14, 14 'correspond to the actual distribution of the braking load to the front and rear wheels.

The master cylinder 11 used is one that generates two braking pressures by a tandem system.

The hydraulic unit 12 generally has two types (not shown) of a pump, an electromagnetic valve, a cutoff valve, and a flow control valve instead of the cutoff valve. The former is a three-position system in which the braking pressure of the master cylinder is controlled to any one of pressure reducing, holding, and pressurizing conditions, and the latter is a two-position system in which the braking pressure is controlled to either pressure reducing or pressing. In this embodiment, any of those methods may be used.

The electronic control circuit 13 calculates the wheel speed, the reference wheel speed, the acceleration, the vehicle estimated speed, the slip ratio, etc. according to the internal program based on the pulse signals from the wheel speed sensors 17, 17 ', 18, 18', and When it is determined that the slip ratio is excessive as a result of the calculation, the pressure is reduced in the direction to unlock the wheels,
Send a command signal for holding to the two hydraulic units 12, 12 ',
When the slip ratio decreases below a predetermined standard, the pressurizing signal is given again to control the wheels to lock.

In this case, the two hydraulic units 12, 12 'are independently controlled by sending the command signals to the respective hydraulic units according to the friction coefficients of the road surfaces of the left and right front wheels.

The details of the hydraulic pressure follow-up valves 14 and 14 'are shown in FIG. This hydraulic pressure follow-up valve 14 is a pressure that detects the equilibrium state of both pressures by introducing the braking pressure P _B ′ on the opposite side system and the control pressure P _R on the same side as this hydraulic pressure follow-up valve 14 into the valve body 141. The equilibrium portion 142 and the cutoff valve 143 provided in the path for supplying the flow of the braking pressure P _B ′ to the rear wheels are provided to cut off this flow.

Cutoff valve 143 is a coil spring 143 _a and poppet 143 _b, are provided on the later-described pressure balance valve 148. Poppet 143 _b is provided in the pressure equilibrium. Poppet 143 _b
It is attached to loosely fitted into the opening 148 _c of the pressure balance valve 148 to open and close the opening. Within valve body 141 partition wall 144 and the pressure equilibrium portion 142 and the three rooms 145 _a, 145 _b, are divided into 145 _c. The braking pressure P _B ′ is introduced from the introduction port 146 ′ _B into the room 145 _a and is supplied to the rear wheel from the port 147 via the opening 148 _c and the room 145 _b .

On the other hand, the control pressure P _R is introduced into the chamber 145 _c from the port 146 _R and presses the pressure balance portion 142, and the pressure balance portion 142 is liquified to the cavity portion forming the chamber 145 _c by the O-ring 142 _a. It is molten and slidable.

When the pressure balance portion 142 moves to the right, the poppet 1
The rod of 43 _b is pushed to open the opening 148 _c . Since the braking pressure P _B ′ is supplied to the rear wheels in this open state, the pressure balancing unit 14
A plurality of grooves (or recesses) 144 _b are provided at the left end of the partition wall so that the right end of the partition wall 2 does not come into close contact with the partition wall 144.

Further, the pressure balance unit 148 has the cut-off valve 143 therein, and is provided in the valve body 141 via an O-ring 148a in _a liquid-tight state and slidably. Port 148 _b is the port
146 ′ _B , a valve seat 148 _d for the cutoff valve 143, and a lip seal 14 for the pressure balancing portion 148.
_8'd are provided. This pressure balancing portion 148 is normally pressed by the elastic force of the spring 148 _e and the braking pressure P _B on the same side as the front wheel introduced from the port 149 into another chamber 148 _f containing this spring, Ports 146 ' _B and 148 _b are held in matching positions.

The antilock brake control device 10 of this embodiment configured as described above operates as follows.

First, when the anti-lock control is not performed, the braking pressures P _B and P _B ′ from the master cylinder 11 pass through the hydraulic pressure units 12 and 12 ′ and are given to the front wheels, and the hydraulic pressure follow-up valve 14,
It is also given to the right and left rear wheels via 14 '.

For example, looking at the left side hydraulic piping,
At 14, the same control pressure is introduced through ports 146 ' _B , 146 _R. When immediately before if the cut-off valve 143 is closed, because the pressure in the room 145 _b is supposed has dropped under braking pressure or the pressure of the room 145 _c overcomes the pressure room 145 _b pressure Move balance section 142 to the right and poppet 1
43 _b is pressed to open the cutoff valve 143. Therefore, the braking pressure
P _B ′ flows from port 146 ′ _B into room 145 _a , opening 14
8 _c, channeled through the room 145 _b to the rear wheel from the port 147.

During the above operation, the braking pressure P _B is introduced into the chamber 148 _f from the port 149 to the pressure balancing valve 148, and the pressure balancing valve 148 is pressed to the left in the figure by the elastic force of the spring 148 _e . , And the braking pressure P _B ′ introduced into the chamber 145 _a in the pressure balance valve 148 is 1
The pressure is the same as the braking pressure P _{B of} 48 _f , but the pressing force from the braking pressure P _B side is large due to the difference in the pressure receiving area.Therefore, the pressure balance valve 148 is kept in the normal position shown in the figure. is there. The above operation is exactly the same for the hydraulic pressure follow-up valve 14 '.

Therefore, when antilock control is not being performed,
The same braking pressure as that of the front wheels is always sent to the rear wheels, and normal brake braking can be performed on the left and right sides.

When the antilock control is started, the slip ratio increases when the brake pedal is excessively depressed and the wheels are suddenly locked, and when the electronic control circuit 13 determines that the slip ratio is excessive, the hydraulic unit 12 , 12 ', a command signal for either pressure reduction or holding is output, and the hydraulic pressure of the front wheels is the control pressure.
It is controlled by P _R and P _R ′.

Since the hydraulic control of the front wheels is independently performed by the left and right hydraulic units 12 and 12 ', respectively, when the friction coefficients from the road surface are greatly different between the left and right front wheels, two control pressures P _R , P _R'is controlled to different pressures. Therefore, for example, when the left-side front wheel has a small friction coefficient and is prone to slip, looking at the hydraulic control for the left-side hydraulic unit 12 and the hydraulic follow-up valve 14, the control pressure P _R from the hydraulic unit 12 is the hydraulic pressure. It is smaller than the braking pressure P _B ′ sent to the port 146 ′ _B of the follow-up valve 14, so that a pressure difference is generated between the left and right sides of the pressure balance section 142 of the hydraulic pressure follow-up valve 14, so that the pressure balance section 142 moves to the left.
Then the opening 1 by the biasing force of the cut-off valve 143 spring 143 _a
Close 48 _n .

Therefore, the flow of the braking pressure P _B ′ is cut off, and thereafter the braking pressure P _R
The pressure room 145 _b via the pressure balancing section 142 changes according to the change, hence fluid pressure of the rear wheel on the same side as the front wheel follows the control pressure P _R to the front wheels of the same side. The above operation is exactly the same for the system of the hydraulic unit 12 'hydraulic follow-up valve 14'.

On the other hand, assuming that the front wheel on the right side has more friction than the front wheel on the left side and no slip occurs, the hydraulic unit 1 on the right side
A pressure command signal is output to 2 ', and the control pressure in the pressurized state is the same as the braking pressure.Therefore, the front wheel on the right side is sufficiently braked by the braking pressure, and the same braking pressure is applied to the rear wheels on the right side. Is sent via the hydraulic pressure follow-up valve 14 'on the right and braked.

Therefore, on the road surface side with a small friction coefficient, braking is performed with a correspondingly low pressure, and on the opposite road surface side with a large friction coefficient, braking is performed with a high pressure, so that the optimum braking force on each side is obtained. The effective braking force is exerted to stabilize the driving and shorten the braking distance to the shortest distance.

Since the hydraulic pressure to the rear wheels is sent via the proportional control valves 19 and 19 ', the hydraulic pressure to the rear wheels on the same side as the front wheels is actually a predetermined range or more than the control pressure to the front wheels. The hydraulic pressure is reduced before it is sent, and the braking force is applied according to the actual load distribution of the front and rear wheels.

Next, the operation when a defect occurs in the brake pressure control pipe or the control pressure pipe on either side of the brake pipe system will be described.

It is assumed that a defect has occurred in the piping for the braking pressure P _B and the control pressure P _R of the left system. In this case, the braking pressure P _B is 0 or an abnormally low pressure even if there is a defect in the control pressure pipe. Therefore,
Even hydraulic unit 12 of the right line ', the hydraulic follow-up valve 14' be normal, the braking pressure P _B is not sent successfully, the left front wheel WF _L and the right rear wheel WR _R to braking I can't.

However, as long as the left hydraulic follow-up valve 14 is normal, the braking pressure P _B of the right lineage 'is sent to the left rear wheel WR _L via a hydraulic follow-up valve 14. In this case, in the hydraulic pressure follow-up valve 14, the control pressure P _R also becomes 0 or an abnormally low pressure, so that the pressure balancing unit 142 moves to the left,
Cutoff valve 143 by the biasing force of the spring 143 _a closes the opening 148 _c. Therefore, the braking pressure P _B ′ is blocked in the normal flow path including the cutoff valve 143. Therefore, the pressure equalizing valve 148 is pressed to the right by the braking pressure P _B ′.

At this time, since the braking pressure P _B flowing from the port 149 belongs to the right system, it is also 0 or an abnormal low pressure,
Therefore, the pressure balance valve 148 moves to the right and its lip seal 1
48 'left end surface of the _d is a gap occurs between them away from the surface of the partition 144.

Further, the left end of the pressure balancing valve 148 is formed in a different diameter and small diameter shape as shown in the figure, and this small diameter portion is loosely fitted in the opening of the partition wall portion 144 with a predetermined gap. Thus the bypass passage of the brake pressure P _B 'by the two gaps are formed, the flow of the braking pressure P _B through the bypass passage flows into the room 145 _b, is sent to the rear wheels.

Thus, even if a defect occurs in the piping for the braking pressure P _B and the control pressure P _{R in} the left side system, the braking pressure P _B ′ in the right side system is
Since the left rear wheel can be braked via
The right front wheel and the right rear wheel can be braked. On the contrary, the same is true when a defect occurs in the right system.

Therefore, if there is a defect in the piping for either the left or right braking pressure or control pressure, complete brake braking cannot be performed, but the minimum braking action can be secured with either of the front and rear wheels on the diagonal line. Is extended compared to the normal case, but the braking force is applied to the car to provide stability and safety.

FIG. 3 shows a modified embodiment of the hydraulic pressure follow-up valve 14 of FIG. This valve is different in that the cutoff 143 'is changed from a poppet type to a ball type. In this case the cut-off valve 143 'is spring 143''consists of _b, the cut-off valve 143' _a and the ball 143 rod 142 _'b for opening and closing the opening 148 _c in is provided at the end of the pressure equalization portion 142 There is.

The operation is exactly the same as in the case of FIG.

FIG. 4 is a partial system diagram showing a portion of the hydraulic pipe that is changed when the hydraulic pressure follow-up valve 14 of FIG. 5 is applied to the antilock brake control device 10 of FIG. Basically, it is the same as the case of FIG. 1, except that the braking pressure P _B ′ of the opposite side system is introduced in two branches and the braking pressure P _B on the same side is at the left end position. The difference is that it has been introduced.

FIG. 5 shows a second modified embodiment of the hydraulic pressure follow-up valve 14. In this embodiment, the pressure balance 142 ″ includes two pistons 14 ″.
2 _"L, the _R rod 142 'consists the concatenation in _c, to both ends of the piston 142" _{L, R} are provided rod 142 _"c partition wall portion 144" through the.

As the cutoff valve 143 ″, the same ball type valve as in the case of FIG. 3 is used, and it is provided in the partition wall portion 144 ″. The partition part 144 ″ is provided at the center of the valve body 141 ″. Further, ports 149 ″ for pressurizing the braking pressures P _B and P _B ′ from the outside of the two pistons 142 ″ _L and _R , respectively.
These braking pressures are introduced via _{B 1} , 149 _B. Other members corresponding to the constituent members shown in FIG. 2 are designated by the same reference numerals with "" added thereto.

In normal times when there is no defect in any of the piping systems,
Since the two braking pressures P _B and P _B ′ are in principle equal in pressure, they act on the two pistons to cancel each other out and have no effect.

When the brake is depressed in this state, the pressure balance portion 142 ″ is temporarily displaced from the neutral position shown in the figure to the right during non-antilock control, and the rod 142 ″ _b attached to the right piston 142 ″ _R is cut off. Open without pressing valve 143 ″
Assuming that 144 " _a is closed, the pressure inside chamber 145" _b will drop to less than the braking pressure introduced from port 146 " _R into chamber 145" _c , thus left side By pushing the piston 142 ″ _L of No. 1 to the left, the pressure balancing portion 142 ″ moves to the left and returns to the neutral position shown in the figure.

Therefore, the rod 142 ″ _b pushes the cutoff valve 143 ″ to open the opening 144 ″ _a , and the braking pressure P _B ′ flows through the opening 144 ″ _a into the chamber 145 ″ _b and the other chamber 145 ″ _c. It balances the pressure inside and holds the pressure balance 142 ″ in the neutral position and is delivered to the rear wheel through port 147 ″. Thus, the normal braking operation is performed.

At the time of antilock control, for example, in the case of the left front wheel system, when the control pressure P _R is controlled to be reduced and held, the pressure becomes lower than the braking pressure P _B ′. Therefore, the pressure balance unit 14
2 ″ moves to the right due to the pressure difference, and cutoff valve 143 ″
Thus, the opening 144 ″ _a is closed. After that, the fluctuation of P _R after control is transmitted to the hydraulic pressure to the rear wheel via the pressure balancing portion 142 ″, and the pressure transmission path is switched.

The switching of the pressure transmission path is exactly the same for the right front wheel system. Therefore, when the friction coefficients of the left and right front wheels are significantly different, the rear side on the same side is controlled by the control pressure of the front wheel controlled according to each friction coefficient. It can be seen that the hydraulic pressure of the wheels can be made to follow and independently controlled by the left and right systems, as in the first embodiment.

Next, if the left side system of the two piping systems of the braking pressure and the control pressure fails, the braking pressure P _B and the control pressure P _R are 0 or abnormally low pressure with respect to the hydraulic pressure follow-up valve 14 in FIG. Becomes For this reason, braking pressure is applied to the piston 142 ″ _R on the right side of the pressure balancing portion 142 ″.
P _B ′ acts from the inner and outer surfaces, but its pressure receiving area is
The inner surface side is small due to 2 " _c , so the pressure balance part 142"
Moves greatly to the left to open the cutoff valve 143 ″, and the braking pressure P _B ′ is sent to the rear wheel through the cutoff valve 143 ″.
The opposite is true when the right system fails.

After all, in the case of the embodiment of FIG. 5 as well as the embodiment of FIG. 1, if the left side system fails, the right front wheel and the left rear wheel survive, and if the right system fails, the opposite front and rear wheels. Will survive.

FIG. 6 shows an antilock brake control device according to the third embodiment.
Shows a schematic diagram of 10 ". As shown, two mutually independent braking pressure circuit P _B of the master cylinder 11 in this embodiment, P _B ', one of two hydraulic units 12, 12 'front wheel WF _L of the right and left through the brake cylinders 15, 15 of the _R'
, And the other is supplied to the brake cylinders 16 and 16 'of the left and right rear wheels WR _L and _R via the two hydraulic pressure follow-up valves 14 and 14', and is so-called II piping. Different from the first embodiment.

The braking pressure P _B to the front wheels is sent to the two hydraulic pressure units 12 and 12 ', and is also branched to two hydraulic pressure follow-up valves 14 and 14' in the middle to prevent the failure, and is also piped. The other braking pressure system P _B ′ is also branched on the way to two and is respectively connected to the two hydraulic pressure follow-up valves 14 and 14 ′.

Although the hydraulic pressure follow-up valves 14 and 14 'are of the type shown in FIG. 2 in the illustrated example, it goes without saying that the type shown in FIG. 3 or 5 can be used. However, when the type shown in FIG. 5 is used, the braking pressure piping must be slightly different, as in the embodiment shown in FIG. Other first
The members having the same functions as those in the figure are designated by the same reference numerals.

The operation during non-anti-lock control and anti-lock control is basically the same as in the case of FIG. 1, and during anti-lock control, the rear wheels on the same side as the front wheels are controlled by the control pressures P _B and P _B ′ to the front wheels. The hydraulic pressure to the left and right is independently controlled. But,
When a failure occurs in any of the braking pressures P _B , P _B ′ and the control pressures P _R , P _R ′, the action is slightly different from the case of FIG.

That is, for example, if the braking pressure P _B or the control pressure P _{R in} the left system fails, the pressure becomes 0 or an abnormally low pressure. Therefore, the two front wheels cannot be braked, but the other brake pressure
Since P _B ′ is sent to the rear two wheels via the hydraulic pressure follow-up valves 14 and 14 ′, respectively, the rear two wheels can be braked.

On the contrary, if either the braking pressure P _B ′ or the control pressure P _R ′ on the right side system is lost, the rear two wheels cannot be braked, and only the front two wheels are used for braking. Therefore, at the time of such a failure, at least the front two wheels or the rear two wheels can be braked, so that the minimum braking ability is ensured. Also, regarding the above operation, FIG. 3 and FIG.
It will be obvious that the same result can be obtained when the hydraulic pressure follow valve shown in the figure is adopted.

〔effect〕

As described in detail above, in the first and second inventions, the anti-lock control brake piping system is provided with the hydraulic pressure follow-up valve for controlling the rear wheels on the same side by the control pressure to the front wheels, and the non-antilock control is performed. At times, normal braking can be performed by simply passing the braking pressure of the master cylinder through the hydraulic pressure follow-up valve.When anti-lock control causes the road surface coefficients of the left and right front wheels to differ greatly, braking pressure on either side When a differential pressure occurs in the control pressure to the front wheels, the differential pressure causes the shutoff valve to close and the pressure transmission path to be switched through the pressure balance section, and the control pressure to the front wheels independently controls the hydraulic pressure of the rear wheels on the same side. It has a configuration that can.

Furthermore, as a countermeasure against a failure of the braking pressure system, a pressure balance valve having a built-in shutoff valve is provided in the hydraulic pressure follow-up valve, and the shutoff valve is made inoperative in the event of a failure.

Therefore, by providing a hydraulic pressure follow-up valve with a simple structure, the rear wheel can follow the front wheel on the same side and anti-lock control can be performed, so even if the low friction on the left and right road surfaces is different, optimum brake braking on each side By so doing, traveling stability can be secured and the braking distance can be shortened to the shortest distance, and if a failure occurs in either of the two braking pressure systems, in the first aspect of the invention, on the diagonal line of the survival side braking pressure system. The front and rear wheels, and in the second aspect of the invention, braking of the front two wheels or the rear two wheels is ensured.

The hydraulic pressure follow-up valve according to the third or fourth aspect of the present invention has a different structure but substantially the same function, and it is possible to efficiently switch the transmission path of the braking pressure and the control pressure to the rear wheels, which is simple and economical. It is used in the first and second inventions as a simple valve.

In the fifth invention, the type of the hydraulic pressure follow-up valve is different from that of the first invention, and a part of the piping system is correspondingly changed, but the obtained effect is exactly the same as that of the first invention.

The sixth invention is a case where the hydraulic pressure follow-up valve used in the fifth invention is applied to the second invention, and therefore, the same effect as that of the second invention can be obtained.

In the seventh invention, in any one of the first to sixth inventions, since the proportional control valve is provided in the pipe between the hydraulic pressure follow-up valve and the rear wheel, the hydraulic pressure to the rear wheel is more realistic before and after. It will correspond to the negative distribution by the wheel.

[Brief description of drawings]

FIG. 1 is a schematic system diagram of a first embodiment of an antilock brake control device, FIG. 2 is a detailed view of a hydraulic pressure follow-up valve, and FIG. 3 is a modified embodiment of the hydraulic pressure follow-up valve of FIG. FIG. 4 is a partial piping system diagram when the hydraulic pressure follow valve of FIG. 5 is used, FIG. 5 is another modified embodiment of the hydraulic pressure follow valve, and FIG. 6 is the antilock brake of the second embodiment. It is a schematic system diagram of a control apparatus. 10, 10 ', 10 "... anti-lock brake control device, 11 ... master cylinder, 12, 12 ... hydraulic unit 13 ... electronic control circuit, 14, 14' ... hydraulic follow-up valve, 19, 19 ′ …… Proportional control valve, 142 …… Pressure balancing unit, 143 …… Cutoff valve, 148 …… Pressure balancing valve.

Claims (7)

[Claims] 1. An electronic control circuit for calculating a wheel speed, a vehicle estimated speed, a slip ratio, etc. on the basis of a signal from a wheel speed sensor to judge a wheel lock state and outputting a brake opening / braking command signal, and a brake. The two brake pressures from the master cylinder are used as two independent brake pressure systems, and these brake pressures are controlled by the output signals from the electronic control circuit to the reduced pressure or pressurized state and are supplied to the left and right front wheels. A pressure balance unit that detects the equilibrium state of both the unit and the brake pressure from the master cylinder and the control pressure from the hydraulic unit and detects the equilibrium state of both pressures. A shut-off valve that switches the path so that the control pressure is transmitted to the rear wheels, and a built-in shut-off valve that introduces the braking pressure of the two systems and shuts off by the differential pressure when one braking pressure system fails To the left front wheel system and the right front wheel system, respectively, and two hydraulic pressure follow-up valves consisting of a pressure balancing valve that forms a bypass path in the pressure transmission path so as to send the braking pressure to the rear wheels of the survival side system. In a pair, one of the braking pressures is sent to the hydraulic unit on the same side and also to the shutoff valve of the hydraulic pressure follow-up valve on the other side, and the braking pressure on the other side is symmetrical to this, and Is connected so that the braking pressure on the same side as the front wheels is sent, and if a pressure difference occurs between the braking pressure on the rear wheels and the control pressure during antilock control, the hydraulic pressure on the rear wheels is changed by the control pressure on the front wheels on the same side. Left and right are controlled independently, and when a failure occurs in the braking pressure system on the same side as each hydraulic pressure follow-up valve, the front and rear wheels of the other diagonal braking pressure system that passes through that hydraulic pressure follow-up valve are controlled. An anti-lock brake control device composed of. 2. One of two braking pressure systems from a master cylinder is sent to the two hydraulic units instead of a pipe for sending a braking pressure and a control pressure to the hydraulic unit and the hydraulic pressure follow-up valve. The control pressures controlled by the output signal from the electronic control circuit to the reduced pressure or pressurized state are supplied to the left and right front wheels,
Moreover, one of the braking pressures is branched into two and is also sent to the two hydraulic pressure following valves, and the other braking pressure is branched into two and is directly sent to the path of the shutoff valve of the two hydraulic pressure following valves. , Piping to each hydraulic pressure follow-up valve to send the control pressure on the same side as the front wheel, and when a failure occurs in the braking pressure system on the same side as each hydraulic pressure follow-up valve, only the left and right front wheels, or the left and right wheels The anti-lock brake control device according to claim 1, wherein only the rear wheels are braked. 3. The antilock brake control device according to claim 1, wherein the cutoff valve of the hydraulic pressure follow-up valve is a cutoff valve including a spring means and a poppet. 4. A shutoff valve of the hydraulic pressure follow-up valve is a cut-off valve composed of spring means and a ball, a rod for opening and closing the valve is provided in the pressure balancing portion, and the rod is loosely fitted in the pressure balancing valve. The antilock brake control device according to claim 1 or 2, wherein the cutoff valve is opened and closed by inserting the antilock brake control device. 5. The hydraulic pressure follow-up valve comprises a pressure balancing portion provided at both ends of a rod penetrating a partition wall provided in the valve body, and the shutoff valve provided in the partition wall. Detects the equilibrium of the braking pressures of the two systems introduced to the outside, the equilibrium of the control pressure introduced to the inside and the equilibrium of the other braking pressure introduced via the shutoff valve, and detects the pressure equilibrium when the braking pressure path fails. It is configured to open the shut-off valve with the rod attached to the part to send the braking pressure on the survival side to the rear wheel, and branch the other braking pressure path in response to this hydraulic pressure follow-up valve to branch one hydraulic pressure. The braking pressure path to be sent to the follow-up valve is further divided into two, and is sent, one of which is connected to the path of the shutoff valve, and the other hydraulic-following valve is also a pipe symmetrical to this. The anti-lock brake control device according to 1. 6. The hydraulic pressure follow-up valve comprises a pressure balancing portion provided at both ends of a rod penetrating a partition wall provided in the valve main body, and the shutoff valve provided in the partition wall. Detects the equilibrium of the braking pressures of the two systems introduced to the outside, the equilibrium of the control pressure introduced to the inside and the equilibrium of the other braking pressure introduced via the shutoff valve, and detects the pressure equilibrium when the braking pressure path fails. It is configured to open the shut-off valve with the rod attached to the rear part to send the braking pressure on the survival side to the rear wheel. Corresponding to this hydraulic pressure follow-up valve, the other braking pressure is branched and two hydraulic pressures are applied. The anti-lock brake control device according to claim 2, wherein each of the paths of the follow-up valve to the shutoff valve is further branched into two, and one shutoff valve is connected to the other pressure balance section. 7. A proportional control valve is provided between each hydraulic pressure follow-up valve and a rear wheel, and when the output pressure of the hydraulic pressure follow-up valve exceeds a certain level, the proportional control valve reduces the pressure. The antilock brake control device according to any one of claims 1 to 6.