DE102016210125A1 - Brake system for a vehicle and vehicle with the brake system - Google Patents

Abstract

Vehicles often use hydraulic brake systems. A typical braking system can be found, for example, in the front wheels of motorcycles. In addition, there are also brake systems for two- or multi-lane vehicles, which make it possible to hydraulically control two or more wheel cylinders with a brake actuation cylinder, the wheel cylinders being e.g. act on both brakes on a vehicle axle. It is an object of the present invention to provide a brake system for a vehicle, which is characterized by increased reliability. For this purpose, a brake system 1 for a vehicle with a master cylinder assembly 5, the master cylinder assembly 5 has at least a first slave piston 12a, wherein the first slave piston 12a by a first primary circuit 4a is hydraulically actuated, the master cylinder assembly 5 has at least one first master piston 15a, wherein the first master piston 15a hydraulically actuate a first secondary circuit 8a, wherein the first slave piston 12a and the first master piston 15a are mechanically connected to each other via a coupling element 14, the master cylinder assembly 5 additionally having at least one second slave piston 12a, the second slave piston 12b being connected by a second slave piston 12a Primary circuit 4b is hydraulically actuated, and / or at least one second master piston 15b, wherein the second master piston 15b can hydraulically actuate a second secondary circuit 8b, which are optionally mechanically connected to the coupling element 14, respectively.

Description

The invention relates to a brake system for a vehicle having the features of the preamble of claim 1. The invention further relates to a vehicle with the brake system.

Vehicles often use hydraulic brake systems. A typical braking system can be found, for example, in the front wheels of motorcycles. These brake systems have a manual actuating cylinder, which can be actuated via a brake lever. Usually, a surge tank is connected to the manual actuation cylinder, which ensures a volume compensation in the brake system. By the operation of the manual cylinder pressure is built up in a hydraulic system, which is transmitted to a Radarbeitszylinder, for example, actuates the brake shoes of a disc brake. In addition, there are also brake systems for two- or multi-lane vehicles, which make it possible to hydraulically control two or more wheel cylinders with a brake actuation cylinder, the wheel cylinders being e.g. act on both brakes on a vehicle axle.

It is an object of the present invention to provide a brake system for a vehicle, which is characterized by increased reliability.

This object is achieved by a brake system with the features of claim 1 and by a vehicle with the brake system with the features of claim 10. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description and the accompanying drawings.

The invention relates to a brake system which is suitable and / or designed for a vehicle. The vehicle is preferably designed as a muscle-operated vehicle and / or as an electromotively operated vehicle.

In particular, the vehicle is designed as a light vehicle with a total mass of less than 500 kilograms, preferably less than 200 kilograms and in particular less than 100 kilograms.

The brake system has a master cylinder arrangement, which is designed as a hydraulic acting and / or active assembly. The master cylinder assembly has a plurality of cylinder chambers in which pistons are arranged, as will be explained below. Preferably, the master cylinder assembly is arranged in a housing and / or realized as a one-piece assembly. In particular, a hydraulic fluid is present in the brake system.

The master cylinder assembly has at least one first slave piston, wherein the first slave piston is hydraulically actuated by a first primary circuit. The slave piston is disposed in a cylinder space of the master cylinder assembly, so that a slave piston-cylinder chamber unit results, which can be hydraulically controlled by a hydraulic pressure in the first primary circuit. The master cylinder assembly may also comprise two, three or more such slave pistons, each associated with a cylinder space, so that a second third or further slave piston-cylinder space unit is or are formed by a hydraulic pressure in a second, third or another primary circuit can be controlled hydraulically.

The master cylinder arrangement has at least one master piston. The first master piston is associated with a cylinder space in the master cylinder assembly, so that a first master cylinder-piston chamber unit is formed, which can generate a hydraulic pressure in a first secondary circuit. The master cylinder assembly may also have two, three or more such master piston, which are each associated with a cylinder chamber, so that a second third or more master piston-cylinder chamber unit is formed or which are a hydraulic pressure in a second, third or further Hydraulic secondary circuit can generate.

It is provided that the first slave piston and the first master piston are mechanically connected to one another via a coupling element. Preferably, the first slave piston and the first master piston are forcibly guided together and / or together, so that the two pistons can only move together. Alternatively or additionally, the first slave piston and the first master piston are rigidly connected to one another, in particular in such a way that the positive guidance is provided.

In the context of the invention it is proposed that the master cylinder assembly also has at least the second slave piston, wherein the second slave piston is hydraulically actuated by the second primary circuit. Alternatively or additionally, the master cylinder arrangement has the second master piston, wherein the second master piston can hydraulically actuate the second secondary circuit. The respectively provided piston, namely the second slave piston and / or the second master piston, are mechanically connected to the coupling element. Thus, the master cylinder assembly has at least three pistons, which via the coupling element mechanically, in particular rigid, are connected.

The invention is based on the consideration that a redundant design for the primary circuits and / or for the secondary circuits is formed by the master cylinder arrangement. The invention has the advantage that in the event that two slave pistons and corresponding two primary circuits are present, actuation of the master cylinder assembly and thus the brake system can also take place if one of the primary circuits fails, since the actuation can be done by the other primary circuit. Thus, the failure of a primary circuit does not necessarily lead to the failure of the master cylinder assembly and / or the brake system in its entirety.

Analogous advantages arise with two or more master piston or secondary circuits. In the event that one of the secondary circuits should fail, for example as a result of damage, it is still possible for the other secondary circuit (s) to be actuated via the master cylinder arrangement so that at least part of the secondary circuits can continue to operate. A complete failure of the brake system can thus be effectively prevented by the redundant design.

Considering the brake system systematically, the slave piston, in particular in their entirety, form a summing section and / or the master piston, in particular in their entirety, a distributor section. In particular, the function of the master cylinder arrangement is to summate hydraulic pressure from the entirety of the primary circuits through the common coupling element and distribute it to the secondary circuits.

It is preferably provided that the primary circuits are always designed to be hydraulically independent of each other. Preferably, the primary circuits are so hydraulically independent, so that one of the primary circuits, e.g. by idling, could fail without affecting the other primary circuits. Alternatively or additionally, it is preferred that the secondary circuits are hydraulically independent of each other. In particular, the secondary circuits are designed to be hydraulically independent such that one of the secondary circuits, e.g. by idling, could fail without affecting the other secondary circuits. Alternatively, the secondary circuits are hydraulically independent only when actuated and hydraulically connected together in the unactuated state via a common expansion tank.

This training again emphasizes the idea that the master cylinder assembly is designed so that one of the primary circuits and / or the secondary circuits can fail without jeopardizing the overall function of the master cylinder assembly and / or the brake system.

In principle, it is possible that the coupling element is designed as a one- or multi-part, additional component. In a preferred embodiment of the invention, however, it is provided that at least one of the master piston and at least one of the slave piston are formed together in one piece, so that the coupling element is integrally formed in the common component of master piston and slave piston. It is also possible that the common component has more than one master piston and / or more than one slave piston. It is particularly preferred that the common component represents all master piston and all slave piston and the coupling element.

In a preferred embodiment of the invention, the brake system has at least one expansion tank to compensate for the hydraulic fluid in exactly one, at least one, some or all secondary circuits. Preferably, the surge tank is arranged on the master cylinder assembly. It is particularly preferred that the surge tank is coupled so that a volume compensation can take place in a rest position or the unactuated position of the master cylinder assembly, but is hydraulically decoupled from one or more secondary circuits upon actuation of the surge tank, so that pressure in the secondary circuits can be established ,

In a preferred development of the invention, the brake system has one or more working cylinders, wherein the secondary circuits are each assigned at least or exactly one of the working cylinders. However, it is also possible that one of the secondary circuits are assigned two or more of the working cylinder. Particularly preferably, the working cylinders are designed as brake cylinders which, for example, press a brake pad onto a brake disk.

Furthermore, it is preferred that the brake system has one or more actuation cylinders, wherein the primary circuits are each assigned at least or exactly one of the actuation cylinders. For example, an actuating cylinder for a manual operation and an actuating cylinder for a foot control may be provided.

In a development of the invention, it is provided that the brake system has further equalizing reservoirs for balancing the hydraulic fluid in exactly one, at least one, some or all primary circuits. Everyone is especially preferred the actuating cylinder associated with a surge tank.

In a preferred constructional realization of the invention, the first master piston and / or the first slave piston has a circular area as piston area or effective area. Piston area and / or effective area is preferably understood to mean the area which is perpendicular to a direction of movement of the piston. Furthermore, it is preferred that the second master piston and / or the second slave piston has a circular ring surface or a circular ring segment surface as a piston surface or effective surface. Preferably, the second master piston and / or the second slave piston is arranged concentrically to the first master piston or to the first slave piston. Further, further slave piston and / or master piston may also have an annular surface as the active surface and / or piston surface and be arranged concentrically to the first and second slave piston or master piston.

It can be provided that the piston surfaces and / or active surfaces of master piston, slave piston are each formed with the same area. However, it is preferred that different active surfaces or piston surfaces are used to adjust the hydraulic system in terms of force distribution and / or gain of the input and output side. For example, a brake force distribution between the working cylinders of a front axle and a rear axle is adjustable or realizable.

Another object of the invention relates to a vehicle with the brake system, as described above or according to one of the preceding claims. It is particularly preferred that the working cylinders are designed as one or more brake cylinders, which are preferably distributed to different wheels and / or different axes of the vehicle. The actuating cylinders are preferably designed as at least one manual actuating cylinder and at least one Fußbetätigungszylinder or another manual actuating cylinder. In this embodiment, it is achieved that, for example, in the event of failure of the manual actuation cylinder, the complete braking effect can be achieved by actuating the foot actuation cylinder or the further manual actuation cylinder. In the event that one of the secondary circuits should fail, the other secondary circuits remain active, so that a residual braking effect is given.

Further features, advantages and effects of the invention will become apparent from the following description of preferred embodiments of the invention and the accompanying figures. Showing:

1 a schematic block diagram of a Bremsanalage as an embodiment of the invention;

2 a schematic sectional view of a master cylinder assembly of the brake system in the 1 ;

3 in the same representation as in the 2 an alternative embodiment of the master cylinder assembly.

The 1 shows a schematic block diagram of a brake system 1 for a vehicle, not shown. The vehicle is designed, for example, as a light vehicle, for example as a two- or multi-lane vehicle, which is driven solely by muscle power or as a bio-hybrid with muscle power and / or an electric drive.

The brake system 1 In the illustrated exemplary embodiment, there are two actuating cylinders 2a However, as indicated by dashed lines, it may also have further actuating cylinders. For example, the actuating cylinder 2a is designed as a manual actuating cylinder, which can be operated by a driver of the vehicle by hand. The actuating cylinder 2a is then constructed like the hand-operated cylinder of a motorcycle and has a hand lever which acts on a piston which is arranged in a cylinder, so that a hydraulic pressure can be built up.

The actuating cylinder 2 B For example, is designed as a Fußbetätigungszylinder, the driver can operate the Fußbetätigungszylinder via a foot operation. For example, a foot pedal is operatively connected to a piston in the foot actuation cylinder so that upon actuation of the foot pedal with the foot, a hydraulic pressure can be built up in the foot actuation cylinder. Alternatively, the actuating cylinder 2 B designed as another manual actuating cylinder.

Each of the actuating cylinders 2a , b is with a surge tank 3a , b, which makes it possible, a volume balance in a hydraulic fluid in the actuating cylinders 2a to create b. The expansion tank 3a , b are so with the actuating cylinders 2a , b hydraulically connected, so that in an unactuated state, a volume compensation, in the actuated state, however, the expansion tank 3a , b from the actuating cylinder 2a , b is disconnected so that it can build up hydraulic pressure.

The actuating cylinder 2a , b build the hydraulic pressure in a first primary circuit 4a and in a second primary circuit 4b on. The first primary circuit 4a is hydraulic with the first actuating cylinder 2a , the second primary circuit 4b is hydraulic with the second actuating cylinder 2 B connected. In the primary circuits 4a , b is hydraulic fluid to transmit the pressure.

On the other side are the primary circuits 4a , b hydraulically with a master cylinder assembly 5 connected, which in connection with the 2 and 3 is explained in detail. In particular, the primary circuits 4a , b with a summation section 6 the master cylinder assembly 5 connected. The master cylinder assembly 5 also has a distributor section 7 on, which is a first secondary circuit 8a and a second secondary circuit 8b connect. Optionally, further secondary circuits may be provided. The secondary circuits 8a , b are arranged hydraulically parallel to each other. The secondary circuits 8a , b are each with a working cylinder 9a , B hydraulically coupled, so that a hydraulic pressure from the master cylinder assembly 5 to the working cylinders 9a , b can be routed and these can be operated. The working cylinders 9a , B are formed for example as a brake cylinder.

At one of the secondary circuits 8a , b can also use several of the working cylinder 9a , b be arranged. So it is possible, for example, that through a secondary circuit 8a or 8b two working cylinders 9a , b, which are assigned to a common axis of the vehicle, are actuated. In this way it is possible, for example, all brake cylinders as working cylinder of an axle through a secondary circuit 8a or 8b to press. The other secondary circuit 8b , a may for example be associated with a front axle. However, it is also possible, as indicated by the dashed lines, that further secondary circuits are provided with further working cylinders.

The master cylinder assembly 5 is with a surge tank 10 hydraulically connected. The exact structure of the master cylinder assembly 5 will be related to the 2 explained.

The 2 shows the master cylinder assembly 5 in a schematic sectional view as an embodiment of the invention. The master cylinder assembly 5 has a housing 11 on which in the cross section shown rectangular, but in a plan view from above, for example, circular. The housing 11 is formed in this example as two half-shells.

On one side, here at the top, are the hydraulic inputs of the first and second primary circuits 4a , b shown. The first primary circuit 4a becomes central or center of the master cylinder assembly 5 supplied, the second primary circuit 4b is radially spaced therefrom with respect to a central axis Z.

On the other side, here at the bottom, are the first secondary circuit 8a and the second secondary circuit 8b hydraulically connected. The first secondary circuit 8a is opposite to the first primary circuit 4a , the second secondary circuit is opposite to the first primary circuit 4b connected.

As already related to the 1 explained, the master cylinder assembly 5 in a summation unit 6 and in an adjustment unit 7 be divided logically, structurally or constructively. In this example, the summation unit becomes 6 through a first half shell of the housing 11 and the distribution unit through a second half shell of the housing 11 educated.

In the summation unit 6 is a first slave piston 12a , which has a circular surface as a piston surface, and a second slave piston 12b , which has a circular ring surface as a piston surface, arranged concentrically to one another. The first slave piston 12a is in a first slave cylinder room 13a , the second slave piston 12b is in a second slave cylinder room 13b arranged so that in each case a slave piston-cylinder unit is formed. In operation, the first slave cylinder space 13a and the second slave cylinder space 13b hydraulically decoupled or isolated from each other, so that no hydraulic fluid can be transferred from one room to the other room.

The first slave piston 12a and the second slave piston 12b are together on a coupling element 14 arranged, which the two slave pistons 13a , b rigidly interconnected so that they are positively coupled or constrained. Thus, the two slave pistons 12a , b only be operated together. In the event that additional primary circuits are connected, additional slave pistons with slave cylinder spaces in the housing 11 arranged or integrated and with the coupling element 14 get connected.

On the side of the distribution unit 7 there is a first master piston 15a and a second master piston 15b , The first master piston 15a has as a piston surface a circular area, the second master piston 15b has a circular surface as a piston surface. The first master piston 15a is in a first master cylinder room 16a arranged, the second master piston 15b is a second master cylinder room 16b arranged so that two master piston-cylinder units are created. In the event that additional secondary circuits are to be connected, further master piston and other master cylinder spaces can be in the housing 11 to get integrated.

The master piston 15a , b are each with the coupling element 14 rigidly connected so that they in the axial direction or in the direction of the Z-axis only together and also only together with the slave piston 12a , b can move.

The expansion tank 10 is to the distribution unit 7 coupled so that a volume compensation can take place when the coupling element 14 with the slave and master piston 12a , b, 15a , b, is in an unactuated state, as shown in FIG 2 is shown. Once the master cylinder assembly 5 is pressed, the master piston 15a , b into the corresponding master cylinder chambers 16a , b retracted, so that the hydraulic connection between the expansion tank 10 and the master cylinder spaces 16a , b is interrupted and pressure in the secondary circuits 8a , b can be built.

The first and second slave cylinder spaces 13a , B and possibly further Nehmerzylinderräume are in each operating position of the master cylinder assembly 5 hydraulically separated from each other. This is the master cylinder assembly 5 redundant, because in case of failure of one of the primary circuits 4a , b the other primary circuit the coupling element 14 with the pistons firmly attached to it 12a , b, 15a , b can move and thereby pressure in the secondary circuits 8a , b can muster.

The first and the second master cylinder space 16a , B and possibly further Nehmerzylinderräume are in the actuated operating position of the master cylinder assembly 5 hydraulically separated from each other. It is possible that in case of failure of a secondary circuit 8a , b the other secondary circuit 8b , a can still be operated. This is with the present brake system 1 or the master cylinder assembly 5 created a redundant and thus fail-safe braking system.

In the 3 is a second embodiment of the master cylinder assembly 5 for the brake system in the 1 shown. The difference to the embodiment in the 2 is that the coupling element 14 with the first and second slave pistons 12a , b as well as with the first and second master piston 15a , b is integrally formed.

LIST OF REFERENCE NUMBERS

1

 braking system

2a, b

actuating cylinder

3a, b

Reservoirs

4a

 first primary circuit

4b

 second primary circuit

5

 Master cylinder assembly

6

 Summierabschnitt

7

 manifold section

8a

 first secondary circuit

8b

second secondary circuit

9a, b

working cylinder

10

 surge tank

11

 casing

12a

first slave piston

12b

second slave piston

13a

 first slave cylinder space

13b

second slave cylinder space

14

 coupling element

15a

 first master piston

15b

 second master piston

16a

 first master cylinder room

16b

 second master cylinder space

Z

central axis

Claims (10)

Brake system ( 1 ) for a vehicle having a master cylinder arrangement ( 5 ), wherein the master cylinder arrangement ( 5 ) at least one first slave piston ( 12a ), wherein the first slave piston ( 12a ) by a first primary circuit ( 4a ) is hydraulically actuated, wherein the master cylinder assembly ( 5 ) at least one first master piston ( 15a ), wherein the first master piston ( 15a ) a first secondary circuit ( 8a ) can operate hydraulically, wherein the first slave piston ( 12a ) and the first master piston ( 15a ) via a coupling element ( 14 ) are mechanically interconnected, characterized in that the master cylinder arrangement ( 5 ) additionally at least one second slave piston ( 12a ), wherein the second slave piston ( 12b ) by a second primary circuit ( 4b ) is hydraulically actuated, and / or at least one second master piston ( 15b ), wherein the second master piston ( 15b ) a second secondary circuit ( 8b ) can hydraulically actuate, which optionally with the coupling element ( 14 ) are mechanically connected. Brake system ( 1 ) according to claim 1, characterized in that the slave piston ( 12a , b) a summing section ( 6 ) and / or the master piston ( 15a , b) a distributor section ( 7 ) form. Brake system ( 1 ) according to one of the preceding claims, characterized in that the primary circuits ( 4a , b) hydraulically independent are formed from each other and / or that the secondary circuits ( 8a , b) are hydraulically independent of each other. Brake system ( 1 ) according to one of the preceding claims, characterized in that at least one of the master piston ( 15a , b) and at least one of the slave pistons ( 12a , b) are formed in one piece. Brake system ( 1 ) according to one of the preceding claims, characterized by at least one expansion tank ( 10 ) for balancing the hydraulic fluid in exactly one, at least one, some or all of the secondary circuits ( 8a , b). Brake system ( 1 ) according to one of the preceding claims, characterized by one or more working cylinders ( 9a , b), whereby the secondary circuits ( 8a , b) is assigned in each case at least one of the working cylinder. Brake system ( 1 ) according to one of the preceding claims, characterized by one or more actuating cylinders ( 2a , b), whereby the primary circuits ( 4a , b) in each case at least or exactly one of the actuating cylinders ( 2a , b) is assigned. Brake system ( 1 ) (According to claim 7, characterized in characterized by at least a surge tank 10 ) for balancing the hydraulic fluid in exactly one, at least one, some or all of the secondary circuits ( 8a , b). Brake system ( 1 ) according to one of the preceding claims, characterized in that the first master piston ( 15a ) and / or the first slave piston ( 12a ) has a circular area as a piston surface and that the second master piston ( 15b ) and / or the second slave piston ( 12b ) has an annular surface as a piston surface. Vehicle with the brake system ( 1 ) according to any one of the preceding claims.

Images