DE10319338A1 - Hydraulic braking system operating independently on vehicle wheels, has independent braking circuits with supply line connection between them - Google Patents

Abstract

The braking circuits (VL, VR; HL, HR) are independent of each other, yet there is a hydraulic connection of the supply lines (21, 22; 26, 29) of at least two braking circuits(VL, VR; HL, HR).

Description

The The invention relates to a brake system for vehicles, in particular for motor vehicles.

such Brake systems have at least two independent brake circuits on. The wheels the vehicle are associated with hydraulic actuator having wheel brakes. The hydraulic actuators each have at least one working chamber on. Each brake circuit has a supply line and a return line on, by the hydraulic fluid flows from the pressure source to the actuator or from the actuator to the reservoir. There are in the supply and return lines Inlet or exhaust valves arranged to a in the actuators desired Pressure to control or regulate.

The Inlet and exhaust valves are not primarily the brake function, they are provided by the brake pressure a single or in groups of brakes across from to change a form. hereby can Systems such as anti-lock braking systems, electronic vehicle dynamics systems and the like can be realized. To active, from the operation of the brake pedal independent Generation of pressure in the supply lines may provide pressure pumps be, with each brake circuit preferably has a pressure pump.

Out establish the reliability, it is usually provided that the brake pedal acts on a master cylinder acting as a pressure source for the Brake circuits serves. This is a mechanical, by function independent of electronic components Fallback given, even if a brake circuits brake on the At least one further brake circuit braking is performed can.

Out establish the installation space and the costs would be It's beneficial if on a hydraulic connection between brake pedal and brake circuits and thus omitted on the master cylinder could be.

A brake system for a motor vehicle in which no hydraulic connection between the driver-actuated brake pedal and the brake circuits is, for example, based on the generic DE 198 35 352 known. Here, the braking request is detected by sensors on the brake pedal and fed these signals control means. The brake pressure is generated by pressure pumps.

On Disadvantage of the brake system described in this reference is it that when a simple error occurs in certain Components, such as a hydraulic unit, one of the brake circuits no longer functional is. A substantial, non-compensable loss in the braking ability of the Vehicle enters, although it is still possible to the vehicle too brake.

task the invention it is in contrast, a Brake system without hydraulic connection between the brake pedal and the brakes in such a way that even the failure of a hydraulic unit one of the brake circuits does not cause the failure of the affected brake circuit leads.

This The object is achieved by a Brake system solved according to the independent claims.

A brake system according to the invention points the wheels the vehicle assigned brakes. The brakes are by means of hydraulic brake actuator actuated. This can be the operation independent of brakes done from each other. The brake plates each have at least a working chamber. Furthermore, controllable intake and exhaust valves provided, the filling or emptying of the Control working chambers of the brake discs. This lead to pressurized supply lines from pressure pumps to brake actuators, while return lines brake plate with storage containers connect. over a brake pedal, the driver's braking request can be detected, resulting from a control device at least due to the braking request a brake operation is produced. At least two brake circuits are provided, which brakes are assigned, each brake circuit supply lines and return lines, a reservoir and a pressure pump for pressurized feeding the supply lines having hydraulic fluid. According to the invention the brake circuits are independent from each other, but at least between the supply lines two brake circuits a hydraulic connection.

The Hydraulic connection between the supply lines of two brake circuits has the advantage that one of the brake circuits in case of failure its pressure supply with pressurized hydraulic fluid can be supplied by at least one other brake circuit. In order to can also then all brake plates continue to be supplied with pressure and controlled, the brake system then remains functional in all brake circuits and any control and regulating systems working with brake interventions, such as anti-lock braking systems and vehicle dynamics control systems, remain functional.

refinements of the invention provide that the hydraulic connection of the supply line at least two brake circuits is formed switchable with each other. For this is - in particular in each brake circuit - one provided with the supply line connected pressure connection valve.

According to advantageous Embodiment of the invention may be at least one of the brake circuits associated with the supply line switchable connected pressure accumulator his. This can in particular via the pressure connection valve one of the brake circuits done. The accumulator can in particular in the area of the hydraulic connection of the supply lines of two Brake circuits arranged with each other and in particular with respect to each the two brake circuits through a pressure connection valve of the brake circuit be separable.

Further Embodiment of the invention provide that the return lines the brake circuits whose supply lines are connected to each other, also hydraulically connected to each other. This has among other things the Advantage that between the brake circuits so a balance of the amount the hydraulic fluid can be made. One of the affected brake circuits one other added hydraulic fluid can then be returned to the output brake circuit. Again, at least at a portion of the brake circuits, a return valve be provided by the hydraulic connection switchable is. In particular, return connection valves are provided in each brake circuit. It is enough then the return valves connect to each other through a connecting line.

refinements The invention provide that the pressure pumps of the brake circuits as bidirectionally promoting Pumps are formed. To improve the fault tolerance can about that provided that between the reservoir and the pressure pump a switchable Shut-off valve is arranged.

Become in the return lines Switching valves are provided, which regulate the return flow of brake fluid in the reservoir prevent, so the brake circuit is designed so that it is compared to any conceivable simple error is fault tolerant.

A brake system according to the invention provides that the brake system of identically constructed modules each module contains all the components of a brake circuit, and at least at the supply lines, preferably also at the return lines, in each case one connection point for producing a hydraulic Connection is formed with each other. Thus, a fault tolerant Brake system with multiple brake circuits in a simple way be generated that several, for example, two identical modules be used in the vehicle, the modules with each other on the Connection points of the pressure supply lines - preferably also the connection points the return lines - with each a connecting line to each other. By the modular structure receives you have a high flexibility in the construction of the plant. In particular, the system can be decentralized be arranged in several places in the vehicle. At the same time a risk of confusion of the modules during assembly excluded, that they are identical to each other. This also has a positive Influence on the common part number of both the components of the vehicle as well as the components of the modules with each other. According to advantageous Design is in each case before the connection points a switching valve, namely a Pressure connection valve or a return connection valve arranged. In the connecting line of the supply line, a pressure accumulator be arranged.

According to others Embodiment of the invention, a module comprises the components container, pressure pump, Supply lines, return lines, inlet and exhaust valves and at least one wheel brake.

Otherwise it is the invention also explained in more detail with reference to the embodiments illustrated in the drawings. there shows:

1 the circuit diagram of a first brake system according to the invention; and

2 the circuit diagram of a second brake system according to the invention with a modular design

The 1 shows the schematic circuit diagram of a first brake system according to the invention. In contrast to the brake system of 2 has the brake system the 1 no modular design. Rather, it is designed as a coherent unit. Nevertheless, the two brake circuits (VL and VR on the one hand and HL and HR on the other hand) at the in 1 illustrated embodiment with each other substantially identical. Brake systems according to 1 and 2 have pressure sensors in several places 5.1 . 5.2 . 10.1 . 10.2 . 11.1 and 11.2 on, which are used to capture the pressures and thus the detection and monitoring of the operation of the brake system and possibly also the control of braking interventions. They are part of the brake circuits and accordingly also part of the modules 41 . 42 ( 2 ). The measured values of the pressure sensor reindeer 5.1 . 5.2 . 10.1 . 10.2 . 11.1 and 11.2 can in particular the control device 32 be supplied.

The brake system 40 of the 1 has two separate brake circuits (VL, VR and HL, HR). Apart from the so-called black-and-white division shown in the two figures, other assignments of the brakes in brake circuits are also known, the type of assignment of the brakes to the brake circuits having no difference in relation to the invention.

The operation of the brake pedal 33 by the driver is by means of the pedal travel sensor 30 detected. The signal of the pedal travel sensor 30 represents the braking request of the driver. This signal is in the control unit 32 evaluated. In the control unit 32 is at least using the signal of the pedal travel sensor 30 an operation of wheels associated brakes VL, VR, HL and HR determined and then by appropriate control of the intake valves 6.1 . 6.2 . 7.1 and 7.2 and the exhaust valves 8.1 . 8.2 . 9.1 and 9.2 a corresponding pressure in the working chambers of the brake discs of the wheel brakes 17.1 . 17.2 . 18.1 and 18.2 be controlled. In addition to the signals of a pedal travel sensor, in particular corresponding control signals of an anti-lock braking system (ABS) and of other systems that perform braking interventions - such as a driving dynamics control system that also carries out active braking interventions without the driver's request for braking - can also be taken into account.

The wheel brakes 17.1 and 17.2 are associated with the front left and front right wheels and belong to the first brake circuit VL, VR. To operate the wheel brake 17.1 respectively. 17.2 is at this over the inlet valve 61 respectively. 62 and the exhaust valve 8.1 respectively. 8.2 set a desired hydraulic pressure.

The pressure pump serves to generate the supply-side brake pressure 1.1 which is capable of conveying in both directions. The pressure pump 1.1 is via the suction line 20 from the reservoir 27 fed, being between pressure pump 1.1 and reservoir 27 a shut-off valve 2.1 is arranged. The shut-off valve 2.1 Among other things, it is used in case of a faulty non-switching off of the pressure pump 1.1 the suction connection to the reservoir 27 to interrupt and thus an uninterrupted pumping the pressure pump 1.1 to prevent.

From the outlet side of the pressure pump 1.1 leads the supply line 22 to the intake valves 6.1 and 6.2 that the wheel brakes 17.1 and 17.2 are assigned, so that the wheel brakes 17.1 and 17.2 be acted upon with pressurized hydraulic fluid.

The return flow of hydraulic fluid from the wheel brakes 17.1 . 17.2 back to the reservoir 27 via the assigned outlet valve 9.1 respectively. 9.2 and the return line 24 , In the return line 24 is a switching valve 14.1 arranged, which connects to the reservoir 27 can lock. In case of a defect of an exhaust valve 8.1 or 8.2 can still by locking the switching valve 14.1 a brake pressure in the wheel brakes 17.1 and 17.2 be maintained.

By appropriate activation of the pressure pump 1.1 , the intake valves 6.1 and 6.2 and the exhaust valves 8.1 and 8.2 can in the wheel brakes 17.1 and 17.2 of the first brake circuit VL, VR independently of each other, any brake pressure can be generated. About that between the two wheel brakes 17.1 and 17.2 arranged balance valve 12 can connect the wheel brakes 17.1 and 17.2 be prepared, so that, for example, in case of failure of one of the intake valves 6.1 . 6.2 a pressure supply of the corresponding wheel brake via the inlet valve 6.2 respectively. 6.1 the other wheel brake is enabled. The same applies in case of defect of one of the exhaust valves 8.1 . 8.2 ,

Of the second brake circuit corresponds in its construction to the first brake circuit. Without again on the above already set out with respect to the first brake circuit To address the operation of such a brake circuit, below the second brake circuit briefly described.

The second brake circuit HL, HR has the reservoir 28 on. The suction line 19 in which the shut-off valve 2.2 is arranged, leads to the pressure pump 1.2 , From the pressure pump 1.2 leads the supply line 21 to the intake valves 7.1 and 7.2 and from there to the respective wheel brakes 18.1 respectively. 18.2 the left rear wheel or the right rear wheel. From there, the return line leads 23 via the corresponding outlet valve 9.1 respectively. 9.2 as well as the switching valve 14.2 back to the reservoir 28 ,

Thus, in each of the brake circuits VL, VR and HL, HR, each simple error except the failure of the pressure pump 1.1 respectively. 1.2 be compensated. In the case of the occurrence of a single error, although not always individual wheel controls can be maintained, apart from a possibly required change of the control strategy of a controller, such as an ABS, the system is still fully functional and thus fault-tolerant.

In order to be able to compensate also the last single error connects the connection line 29 the supply line 22 the first brake circuit VL, VR with the supply line 21 of the second brake circuit HL, HR. In this connection line 29 is the pressure connection valve 25.1 arranged. Thus, in case of failure of the pressure pump 2.1 respectively. 2.2 one of the brake circuits by switching the connecting line 29 the supply of pressurized hydraulic fluid from the other pressure pump 2.2 respectively. 2.1 out. To the delivery capacity and pressure build-up of the still functioning pressure pump 2.2 or 2.1 Not too much to change can additionally via the pressure connection valve 25.2 the accumulator 4 be looped into the hydraulic circuit in which, for example, with maximum operating pressure acted upon hydraulic fluid is stored. The accumulator 4 can be done by running one of the two pressure pumps 2.1 or 2.2 be refilled. The refilling takes place in particular when the pressure pump 2.1 or 2.2 is not needed to generate a braking intervention.

So that a back-flow compensation between the brake circuits can take place, be it hydraulic fluid from the wheel brakes 17.1 . 17.2 . 18.1 . 18.2 attributed to the reservoir 27 , respectively. 28 In order to make a quantity compensation of the hydraulic fluid of the two brake circuits or to compensate for a hydraulic fluid loss in one of the brake circuits, is also a connection line 26 between the return line 24 the first brake circuit VL, VR and the return line 23 the second brake circuit HL, HR provided. In this connecting line is the return valve 31.1 arranged, through which the hydraulic connection can be manufactured or interrupted selectively.

In normal, error-free operation of the brake system 40 are both the connection line 29 between the supply lines 22 . 21 as well as the connection line 26 between the return lines 24 . 23 the two brake circuits and the connection to the accumulator 4 through the pressure connection valves 25.1 . 25.2 or the return valve 31.1 hydraulically separated from each other. The two brake circuits are therefore independent of each other in normal operation, but can be connected together if necessary. The connection line 29 between the two supply lines 22 . 21 thus makes it possible for a redundant design of the pressure pumps 2.1 and 2.2 to renounce and still achieve a fault tolerance against single errors of the entire system.

The 2 shows the representation of a second embodiment of a brake system according to the invention.

The components of the 1 and 2 are largely the same, the main difference is seen in their division into modules. Therefore, corresponding components of the two figures have been given the same reference numerals. As far as regarding 2 nothing to the contrary can be added to the description of the corresponding parts of 1 to explain the 2 be resorted to.

In particular, the operation of the brake systems correspond to 1 and 2 each other, so this for this 1 set out accordingly also for 2 applies.

The detection of the driver's braking request via the brake pedal 33 , its operation via the pedal travel sensor 30 detected and in the control device 32 is evaluated. In the control device 32 is due to signals supplied to the signal of the pedal travel sensor 30 include, the operation of the wheel brakes 17.1 . 17.2 . 18.1 and 18.2 controlled.

It is a brake system according to the invention 40 represented, in which for each of the two brake circuits VL, VR or HL, HR a module 41 . 42 is provided. The two modules 41 and 42 are identical to each other. The first module 41 contains the brake circuit VL, VR of the wheel brakes 17.1 and 17.2 that are assigned to the two front wheels. The second module 42 contains the brake circuit HL, HR of the wheel brakes 18.1 and 18.2 , which are assigned to the two rear wheels.

The module 41 of the first brake circuit VL, VR contains the pressure pump 1.1 , the supply lines 22 , the intake valves 6.1 and 6.2 , the wheel brakes 17.1 and 17.2 the two front wheels, the exhaust valves 8.1 and 8.2 , the return line 24 with the switching valve arranged therein 14.1 , the reservoir 27 and the shut-off valve 2.1 , A branch from the supply line 22 leads to the pressure connection valve 25.1 , A branch from the return line 24 leads to the return valve 31.1 , Immediately to the pressure connection valve 25.1 and the return valve 31.1 closes in each case a connection point AS for the connecting lines 26 and 29 on.

The module 42 of the second brake circuit HL, HR contains the pressure pump 1.2 , the supply lines 21 , the intake valves 7.1 and 7.2 , the wheel brakes 18.1 and 18.2 the two rear wheels, the exhaust valves 9.1 and 9.2 , the return line 23 with the switching valve arranged therein 14.2 , the reservoir 28 and the shut-off valve 2.2 , A branch from the supply line 21 leads to the pressure connection valve 25.2 , A branch from the return line 23 leads to the return valve 31.2 , Immediately to the pressure connection valve 25.2 and the return valve 31.2 includes each have a connection point AS for the connecting lines 26 and 29 on. It is for clarification purposes in the module 42 the location of pressure connection valve 25.2 and return valve 31.2 the module 1 drawn facing. In fact, the two modules 41 and 42 However, be executed completely identical.

The two modules can be mounted at different locations in the vehicle, but could also be executed directly next to each other or blocked with each other. The modules 41 and 42 be with each other via the connecting lines 26 and 29 connected, which are coupled to the connection points AS. These are connection points, as they are generally known from fluidic systems ago. There are in particular screw, bayonet and otherwise secure connectors in question. In order to prevent permutations when connecting the connection lines, the connections AS can be made so different that only the appropriate connection line can be connected to a connection point.

The connection line 26 connects the two return lines 24 and 23 the modules 41 and 42 together. The connection line 29 connects the two supply lines 22 and 21 the modules 41 and 42 , So the first and the second brake circuit with each other. In the connection line 29 is the accumulator 4 arranged, which is only available for the brake system and must not be provided redundantly for reasons of fault tolerance. The connection lines 26 . 29 can, if necessary, with the accumulator 4 , be designed as a coherent component.

A component difference from the 1 is in the 2 also to see that two return valves 31.1 and 31.2 are present, although purely functional, a valve would suffice. This additional expense is compensated by the advantage that the two modules can be designed to be identical.

As well as the brake system according to the 1 is the brake system of 2 compared to any single fault in the brake system executed fault tolerant.

Of course, not only two-circuit brake systems, as described, be carried out according to the invention. Even with brake systems with other brake circuits, the invention can be used. In a particularly simple embodiment, this can be done in a modular brake system, which consists of several identical modules. For example, are the modules the same as the module? 41 designed, it is sufficient to connect all modules together, the connecting lines 26 and 29 form as all modules connecting ring lines. If an even number of brake circuits given, so it meets the requirements of fault tolerance also, if always two of the brake circuits with each other by connecting lines 26 . 29 are connected. The pairs of brake circuits can then optionally, as in 1 represented as an assembly or as a pair of modular assemblies, as in 2 shown executed. A further connection of the pairs of brake circuits with each other is not required.

Claims (10)

Brake system for vehicles with wheel brakes assigned to the wheels of the vehicle and actuatable by means of hydraulic brake actuators ( 17.1 . 17.2 . 18.1 . 18.2 ), the operation of wheel brakes ( 17.1 . 17.2 . 18.1 . 18.2 ) is independently feasible; - controllable inlet valves ( 6.1 . 6.2 . 7.1 . 7.2 ) and exhaust valves ( 8.1 . 8.2 . 9.1 . 9.2 ) for the controlled pressurization of the wheel brakes ( 17.1 . 17.2 . 18.1 . 18.2 ); - supply lines ( 21 . 22 ) for the pressurized supply of hydraulic fluid from pressure pumps ( 1.1 . 1.2 ) to the wheel brakes ( 17.1 . 17.2 . 18.1 . 18.2 ) and return lines ( 23 . 24 ) for returning hydraulic fluid from the wheel brakes ( 17.1 . 17.2 . 18.1 . 18.2 ) in storage container ( 27 . 28 ); and with - a driver-actuated brake pedal ( 33 ) for detecting a braking request and a control device ( 32 ) for generating brake actuations at least due to the braking request; wherein at least two brake circuits (VL and VR, HL and HR) are provided, which wheel brakes ( 17.1 . 17.2 . 18.1 . 18.2 ), each brake circuit (VL and VR, HL and HR) supply lines ( 21 . 22 ) and return lines ( 23 . 24 ), a reservoir ( 27 . 28 ) and a pressure pump ( 1.1 . 1.2 ) for pressurized feeding of the supply lines ( 21 . 22 ) with hydraulic fluid, characterized in that the brake circuits (VL and VR, HL and HR) are independent of each other, but a hydraulic connection of the supply lines ( 21 . 22 ; 26 . 29 ) at least two brake circuits (VL and VR, HL and HR) with each other. Brake system according to claim 1, characterized in that the hydraulic connection of the supply lines ( 21 . 22 ) at least two brake circuits (VL and VR, HL and HR) is formed switchable with each other, including in particular a connecting line ( 29 ) with at least one associated pressure connection valve ( 25.1 . 25.2 ) is provided. Brake system according to one of claims 1 or 2, characterized in that at least ei ner of the brake circuits (VL and VR, HL and HR) one with the supply line ( 21 . 22 ) Switchable pressure accumulator ( 4 ) having. Brake system according to one of the preceding claims, characterized in that the return lines ( 23 . 24 ) of the brake circuits, their supply lines ( 21 . 22 ) are hydraulically connected to each other, are hydraulically connected to each other, wherein the hydraulic connection is formed in particular switchable, including in particular a connecting line ( 26 ) with at least one associated return valve ( 31.1 . 31.2 ) is provided. Brake system according to one of the preceding claims, characterized in that between reservoir ( 27 . 28 ) and pressure pump ( 1.1 . 1.2 ) a switchable shut-off valve ( 2.1 . 2.2 ) is arranged. Brake system according to one of the preceding claims, characterized in that in return lines ( 23 . 24 ) a switching valve 14.1 . 14.2 ) is provided. Brake system for vehicles, whereby the brake system consists of identically constructed modules ( 41 . 42 ), each module ( 40 . 41 ) includes all components of a brake circuit (VL and VR, HL and HR), one component comprising a supply line ( 21 . 22 ), and wherein on the supply lines ( 21 . 22 ) each have a connection point (AS) for establishing a connection of the supply lines ( 21 . 22 ) via a connecting line ( 29 ) is trained. Brake system according to claim 8, characterized in that a component of the modules ( 41 . 42 ) a return line ( 23 . 24 ), wherein on the return lines ( 23 . 24 ) each have a connection point for establishing a connection of the return lines ( 23 . 24 ) via a connecting line ( 26 ) is trained. Brake system according to claim 7 or 8, characterized in that a module ( 41 . 42 ) also the components reservoir ( 27 . 28 ), Pressure pump ( 1.1 . 1.2 ), Inlet ( 6.1 . 6.2 . 7.1 . 7.2 ) and exhaust valves ( 8.1 . 8.2 . 9.1 . 9.2 ) and at least one wheel brake ( 17.1 . 17.2 . 18.1 . 18.2 ) includes. Brake system according to one of claims 7 to 9, characterized in that the connection between the supply lines ( 21 . 22 ) an accumulator ( 4 ).