Braking system and motor vehicle

Abstract

The invention relates to a braking system for a motor vehicle, wherein the braking system is divided into two blocks, each block containing a separate electric pressure generator. The invention further relates to a motor vehicle having such a braking system.

Description

[0001] The invention relates to a braking system for a motor vehicle and to a motor vehicle having such a braking system.

[0002] Braking systems are typically used in motor vehicles to decelerate them in a targeted manner. New braking systems are typically based on the pressure generated by a driver in a master brake cylinder being amplified by a linear actuator, or the brake pressure is generated exclusively by a linear actuator based on an electronically sensed driver braking request.

[0003] According to a first example, DE 10 2017 219 827 A1 discloses a braking system with a master brake cylinder and a first electric pressure generator, and according to a second example, a braking system with a first and a second electric pressure generator. The braking systems further comprise a plurality of intake valves.

[0004] DE 10 2013 214 212 A1 describes a braking system for a motor vehicle, which has a master brake cylinder, two electric pressure generators and a plurality of inlet valves.

[0005] Linear actuators are typically integrated into a brake system block, which may also contain other components such as valves or lines. The maximum volume of the linear actuator therefore depends on existing manufacturing constraints in the production of such blocks. This limits the size of motor vehicles that can be operated using a particular production system.

[0006] It is an object of the invention to provide a braking system that is designed alternatively or better in this regard. It is also an object of the invention to provide a motor vehicle with such a braking system.

[0007] This is achieved according to the invention by a braking system and a motor vehicle according to the respective main claims. Advantageous embodiments can be found, for example, in the respective subclaims. The content of the claims is incorporated into the content of the description by express reference.

[0008] The invention relates to a braking system for a motor vehicle. The braking system comprises a first block and a second block, the second block being separate from the first block. The braking system comprises a master brake cylinder arranged in the first block. The braking system comprises a first electrical pressure generator arranged in the first block. The braking system further comprises a second electrical pressure generator arranged in the second block.

[0009] The braking system has a plurality of intake valves.

[0010] The braking system comprises a first group of wheel connections arranged on the first block and connected to the master brake cylinder and the first electric pressure generator via a respective inlet valve. The braking system further comprises a second group of wheel connections arranged on the second block and connected to the second electric pressure generator via a respective inlet valve.

[0011] The braking system according to the invention makes it possible to divide the functionality into two blocks, each with its own electric pressure generator, for example, a linear actuator. This allows a braking system suitable for larger and heavier vehicles to be constructed despite existing restrictions in block manufacturing.

[0012] Inlet valves are typically located directly at the respective wheel connections. This allows pressure or volume to be selectively directed to the respective wheel connection and, for example, forwarded to a connected wheel brake.

[0013] For example, the first group of wheel connections can be assigned to a front axle, and the second group of wheel connections can be assigned to a rear axle, or vice versa. However, a diagonal distribution of the wheel connections is also possible.

[0014] According to one embodiment, the wheel connections of the second group are connected to the master brake cylinder via the respective inlet valves and a connecting line connecting the blocks. By means of such a connecting line, a fluid connection to the wheel connections of the second group can be established from the first block.

[0015] According to one embodiment, an auxiliary brake cylinder is arranged in the second block, wherein the auxiliary brake cylinder has a piston that divides the auxiliary brake cylinder into a first pressure chamber and a second pressure chamber. The first pressure chamber is connected to the master brake cylinder via a connecting line connecting the blocks. The wheel connections of the second group are connected to the second pressure chamber via the respective inlet valves. Such a design also allows the functionality of the master brake cylinder to be distributed between both blocks, which, for example, enables further hydraulic separation and also enables a better allocation of production capacity.

[0016] In this case, for example, pressure is generated from the first block in the first pressure chamber and transferred to the second pressure chamber by the piston. The pressure generated in the second pressure chamber then flows to the wheel connections of the second group.

[0017] The first electric pressure generator can, in particular, be connected to inlet valves connected to the first electric pressure generator via a common connection valve. Likewise, the second electric pressure generator can be connected to inlet valves connected to the second electric pressure generator via a common connection valve. Depending on the design, this may mean that the respective pressure generator is connected to the respective inlet valves only via a connection valve assigned to the pressure generator.

[0018] According to one embodiment, the first electrical pressure guide is connected to each of the inlet valves connected to the first electrical pressure generator via a respective separate connection valve. Likewise, according to one embodiment, the second electrical pressure generator can be connected to each of the inlet valves connected to the second electrical pressure generator via a respective separate connection valve. This allows each inlet valve to be assigned a respective separate connection valve as a connection to the respective pressure generator, which enables even more extensive subdivision and control.

[0019] The intake valves connected to the wheel connections of the first group can be interconnected on the inlet side. Likewise, the intake valves connected to the wheel connections of the second group can be interconnected on the inlet side. This allows pressure equalization between the respective intake valves.

[0020] The inlet valves connected to the wheel connections of the first group can be connected to the master brake cylinder, in particular, via a common isolating valve. Likewise, the inlet valves connected to the wheel connections of the second group can be connected to the master brake cylinder or the auxiliary brake cylinder via a common isolating valve. This allows the use of a common isolating valve, which saves effort.

[0021] Preferably, the first electrical pressure generator and the second electrical pressure generator have independent power supplies. This allows redundancy to be achieved, whereby, for example, if one power supply fails, the other pressure generator can still be used.

[0022] The brake system preferably has at least one brake fluid reservoir and a number of outlet valves. Each wheel connection is preferably connected to a brake fluid reservoir via a respective outlet valve. This allows for advantageous discharge of pressure or fluid into the brake fluid reservoir.

[0023] According to one embodiment, the braking system comprises a first brake fluid reservoir and a second brake fluid reservoir. The braking system comprises a number of outlet valves, each wheel connection of the first group being connected to the first brake fluid reservoir via a respective outlet valve, and each wheel connection of the second group being connected to the second brake fluid reservoir via a respective outlet valve. This allows for a particularly advantageous separation of two hydraulic circuits, each circuit having its own brake fluid reservoir. An additional connecting line for returning hydraulic fluid can thus be advantageously dispensed with.

[0024] According to one embodiment, the master brake cylinder is connected on the intake side to both the first brake fluid reservoir and the second brake fluid reservoir. This allows the circuits to be connected.

[0025] According to a further embodiment, the master brake cylinder is connected on the suction side to the first brake fluid reservoir and not to the second brake fluid reservoir, and / or the auxiliary brake cylinder is connected on the suction side to the second brake fluid reservoir and not to the first brake fluid reservoir. By separately assigning the brake cylinders to the respective brake fluid reservoirs, circuit separation can be achieved, which, for example, makes a return line unnecessary. For example, the first brake fluid reservoir can be arranged on the first block or assigned to the first block, and the second brake fluid reservoir can be arranged on the second block or assigned to the second block.

[0026] The first electrical pressure generator can be connected, in particular, on the intake side to the first brake fluid reservoir and not to the second brake fluid reservoir. The second electrical pressure generator can be connected, in particular, on the intake side to the second brake fluid reservoir and not to the first brake fluid reservoir. This also allows for the circuits to be separated, making it possible, for example, to dispense with a return line.

[0027] The master brake cylinder can, in particular, be a tandem master brake cylinder. However, a single master brake cylinder can also be used. The first electric pressure generator can be a linear actuator, and the second electric pressure generator can also be a linear actuator. Such linear actuators have proven advantageous for typical applications. However, a different type of electric pressure generator, such as a piston pump or a gear pump, can also be used.

[0028] The invention further relates to a motor vehicle with a braking system according to the invention, wherein all embodiments and variants described herein can be used with regard to the braking system. The motor vehicle has a brake pedal coupled to the master brake cylinder. The motor vehicle has a number of wheel brakes connected to the wheel connections of the braking system.

[0029] As already mentioned above, the use of a braking system in such a motor vehicle means that, even with existing restrictions on the production of blocks for a braking system, a significantly higher braking performance can be achieved, which means that the motor vehicle can have significantly larger dimensions and / or masses.

[0030] The motor vehicle can, in particular, have a first wheel brake, a second wheel brake, a third wheel brake, and a fourth wheel brake. The first wheel brake is preferably assigned to a front wheel, and the second wheel brake is preferably assigned to a diagonally opposite rear wheel. The third wheel brake is preferably assigned to a front wheel, and the fourth wheel brake is preferably assigned to a diagonally opposite rear wheel.

[0031] The first wheel brake and the second wheel brake are preferably connected to the wheel connections of the second group. The third wheel brake and the fourth wheel brake are preferably connected to the wheel connections of the first group.

[0032] Such a design achieves a diagonal division of the wheel connections, which has proven to be particularly advantageous for the type of braking system disclosed herein.

[0033] Further features and advantages will become apparent to those skilled in the art from the exemplary embodiment described below with reference to the accompanying drawings. These show: Fig. 1: a braking system according to a first embodiment, Fig. 2: a braking system according to a second embodiment, Fig. 3: a braking system according to a third embodiment, and Fig. 4: a braking system according to a fourth embodiment.

[0034] Fig. 1 shows a braking system 5 according to a first exemplary embodiment of the invention. The braking system comprises a first block 10 and a second block 20. A first linear actuator 12 is arranged in the first block 10 as the first electric pressure generator. Also arranged in the first block 10 is a master brake cylinder 14, to which a brake pedal 15 is connected. This allows a driver to generate pressure in the master brake cylinder 14 by actuating the brake pedal 15, thus indicating a braking request.

[0035] A simulator 18 is arranged in the first block 10 and is connected to the master brake cylinder 14 via a simulator valve SV. In this case, the master brake cylinder 14 is a tandem master brake cylinder. A first isolation valve TV1 is connected to the master brake cylinder 14. When the isolation valve TV1 is closed and the simulator valve SV is open, the master brake cylinder 14 acts on the simulator 18, thereby dissipating the generated pressure. The braking request can be detected by a travel sensor "U / s."

[0036] A first brake fluid reservoir 16 is arranged on the first block 10. This reservoir is connected to the master brake cylinder 14 via a diagnostic valve DV. This allows the master brake cylinder 14 to draw in brake fluid. The first linear actuator 12 is also connected to the first brake fluid reservoir 16 for drawing in brake fluid.

[0037] A second linear actuator 22 is arranged in the second block 20 as a second electric pressure generator. A second brake fluid reservoir 26 is arranged on the first block 20. The second linear actuator 22 is connected to the second brake fluid reservoir 26 for refilling, as shown.

[0038] A first control device ECU1 is provided to control the components of the first block 10. A second control device ECU2 is provided to control the components of the second block 20.

[0039] A first wheel connection R1 and a second wheel connection R2 are arranged on the second block 20. Connected to these are respective brakes B1, B2, which are located externally to the braking system 5. The brakes B1, B2, as well as the brakes to be described below, can, for example, be part of a motor vehicle in which the braking system 5 is installed.

[0040] The wheel connections R1, R2 are connected via a respective inlet valve E1, E2 to a node, which is connected to the master brake cylinder 14 via a second isolation valve TV2. This node is also connected to the second linear actuator 22 via a second connection valve ZV2. The first wheel connection R1 and the second wheel connection R2 can thus be pressurized via the respective inlet valves E1, E2 both from the master brake cylinder 14 via the second isolation valve TV2, and from the second linear actuator 22.

[0041] Accordingly, a third wheel connection R3 and a fourth wheel connection R4 are arranged on the first block 10, to which respective wheel brakes B3, B4 are connected. The third wheel connection R3 and the fourth wheel connection R4 are connected to the aforementioned first isolating valve TV1 via a respective inlet valve E3, E4, thereby enabling pressure to be applied from the master brake cylinder 14. Likewise, the third inlet valve E3 and the fourth inlet valve E4 are connected to the first linear actuator 12 via a first connection valve ZV1, so that pressure can also be applied to the third wheel connection R3 and the fourth wheel connection R4 by means of the first linear actuator 12.

[0042] As shown, the wheel connections R1, R2, R3, R4 are connected to the two brake fluid reservoirs 16, 26 via respective outlet valves A1, A2, A3, A4. This allows pressure or brake fluid volume no longer required at a respective wheel connection R1, R2, R3, R4 to be drained into the brake fluid reservoirs 16, 26.

[0043] The second isolation valve TV2 is connected to the master brake cylinder 14 via a connecting line 30, as shown. To also enable equalization on the return side, a return line 35 is provided between the first block 10 and the second block 20. Thus, there are no completely separate hydraulic circuits.

[0044] By dividing the system into a first linear actuator 12 and a second linear actuator 22, a sufficiently large volume is provided for braking operations. Ideally, this is achieved by dividing the braking system diagonally to ensure the most even use and utilization of the linear actuators 12 and 22.

[0045] The inlet valves E1, E2, E3, E4, the isolation valves TV1, TV2, and the diagnostic valve DV are preferably designed to be normally open, thus enabling a hydraulic fallback function. The other valves mentioned are preferably designed to be normally closed, so that they do not interfere with a hydraulic fallback function.

[0046] The third and fourth wheel connections R3, R4 form a first group of wheel connections. The first and second wheel connections R1, R2 form a second group of wheel connections. This division of the groups is purely for nomenclature purposes and allows for the standard, continuous numbering of valves, wheel connections, and brakes from top to bottom.

[0047] The Fig. 2 to 4 show further embodiments of a braking system 5 according to the invention, the following essentially referring to the differences from the embodiment according to Fig. 1 is addressed.

[0048] Fig. 2 shows a braking system 5 according to a second exemplary embodiment. Each linear actuator 12, 22 is not only connected to a respective sequence valve ZV, but the first linear actuator 12 is also connected to the third inlet valve E3 and the fourth inlet valve E4 via a first sequence valve ZV11 and another first sequence valve ZV12. Likewise, the second linear actuator 22 is connected to the first inlet valve E1 and the second inlet valve E2 via a second sequence valve ZV21 and another second sequence valve ZV22. This allows higher volume flows from the respective linear actuator 12, 22 to be directed to the inlet valves E.

[0049] Fig. 3 shows a brake system 5 according to a third embodiment. The hydraulic circuits between the first block 10 and the second block 20 are completely separated, with an auxiliary brake cylinder 24 being arranged in the second block 20. This is divided into a first pressure chamber 27 and a second pressure chamber 28. A piston 25 is located between these two pressure chambers 27, 28. The first pressure chamber 27 is connected, as shown, to the master brake cylinder 14 via the connecting line 30. As a result, pressure can be transferred from the master brake cylinder 14 into the first chamber 27, whereby the piston 25 is moved and the pressure thus also builds up in the second chamber 28. The second chamber 28 is connected to the main brake cylinder 14 via the aforementioned second isolating valve TV2 according to the embodiment of Fig. 1 is connected to the inlet valves E and wheel connections R arranged in the second block 20. For suction, the additional brake cylinder 24 is connected to the second brake fluid reservoir 26 via a second diagnostic valve DV2.

[0050] By executing according to Fig. 3, the return line 35 can be omitted. This eliminates the need for a connection between the two blocks 10, 20.

[0051] Depending on the basic design of the braking system 5, especially with a black / white distribution, a suitable hydraulic transmission between the master brake cylinder 14 and the auxiliary brake cylinder 24 can also provide advantages in the design of the fallback system, for example, an increased residual volume or a higher pressure level. Since both circuits are completely hydraulically separated, the return line 35 can be omitted.

[0052] Fig. Figure 4 shows a braking system 5 according to a fourth embodiment of the invention. As in Fig. 3 a separation of the hydraulic circuits is provided, whereby in deviation from Fig. 3 each of the two linear actuators 12, 22 is connected to the respective inlet valves E via two connection valves ZV, which in turn corresponds to the idea of Fig. 2. The two in Fig. 2 and Fig. 3 separately shown variations compared to Fig. 1 are therefore in Fig. 4 both realized.

[0053] Redundancy can be achieved by providing a separate power supply for the two linear actuators 12, 22 or the blocks 10, 20 and / or the control units ECU1, ECU2. In a fallback mode, for example, braking can be performed in a single circuit via a normal by-wire function, whereby in a failed circuit or a failed block 10, 20, braking can only be performed via foot force, thus exceeding the required minimum braking effect.

[0054] It should be noted that features may be described in combination in the claims and the description, for example, to facilitate understanding, although they may also be used separately. Those skilled in the art will recognize that such features may also be combined independently with other features or combinations of features.

[0055] References in subclaims may indicate preferred combinations of the respective features, but do not exclude other combinations of features.

Claims

[1] Braking system (5) for a motor vehicle, the braking system (5) comprising: - a first block (10), - a second block (20) which is separate from the first block (10), - a master brake cylinder (14) arranged in the first block (10), - a first electric pressure generator (12) arranged in the first block (10), - a second electric pressure generator (22) arranged in the second block (20), - a plurality of intake valves (E), - a first group of wheel connections (R) arranged on the first block (10) and connected to the master brake cylinder (14) and the first electric pressure generator (12) via a respective inlet valve (E), - a second group of wheel connections (R) which are arranged on the second block (20) and are connected to the second electric pressure generator (22) via a respective inlet valve (E). [2] Braking system (5) according to claim 1, - wherein the wheel connections (R) of the second group are connected to the master brake cylinder (14) via the respective inlet valves (E) and a connecting line (30) connecting the blocks (10, 20). [3] Braking system (5) according to claim 1, - wherein an additional brake cylinder (24) is arranged in the second block (20), - wherein the auxiliary brake cylinder (24) has a piston (25) which divides the auxiliary brake cylinder (24) into a first pressure chamber (27) and a second pressure chamber (28), - wherein the first pressure chamber (27) is connected to the master brake cylinder (14) via a connecting line (30) connecting the blocks (10, 20), - wherein the wheel connections (R) of the second group are connected to the second pressure chamber (28) via the respective inlet valves (E). [4] Braking system (5) according to one of the preceding claims, - wherein the first electrical pressure generator (12) is connected via a common connection valve (ZV1) to inlet valves (E) connected to the first electrical pressure generator (12), and / or - wherein the second electrical pressure generator (22) is connected via a common connection valve (ZV2) to inlet valves (E) connected to the second electrical pressure generator (22). [5] Braking system (5) according to one of claims 1 to 3, - wherein the first electrical pressure generator (12) is connected via a respective separate connection valve (ZV11, ZV12) to each of the inlet valves (E) connected to the first electrical pressure generator (12), and / or - wherein the second electrical pressure generator (22) is connected via a respective separate connection valve (ZV21, ZV22) to each of the inlet valves (E) connected to the second electrical pressure generator (22). [6] Braking system (5) according to claim 5, - wherein the inlet valves (E) connected to the wheel connections (R) of the first group are connected to each other on the input side, and / or - wherein the inlet valves (E) connected to the wheel connections (R) of the second group are connected to one another on the inlet side. [7] Braking system (5) according to one of the preceding claims, - wherein the inlet valves (E) connected to the wheel connections (R) of the first group are connected to the master brake cylinder (14) via a common separating valve (TV1), and / or - wherein the inlet valves (E) connected to the wheel connections (R) of the second group are connected to the master brake cylinder (14) or to the additional brake cylinder (24) via a common separating valve (TV2). [8] Braking system (5) according to one of the preceding claims, - wherein the first electrical pressure generator (12) and the second electrical pressure generator (22) have independent power supplies. [9] Braking system (5) according to one of the preceding claims, - wherein the brake system (5) has at least one brake fluid reservoir (16, 26) and a number of outlet valves (A), - wherein each wheel connection (R) is connected to a brake fluid reservoir (R) via a respective outlet valve (A). [10] Braking system (5) according to one of the preceding claims, - wherein the brake system (5) has a first brake fluid reservoir (16) and a second brake fluid reservoir (26), - wherein the braking system (5) has a number of outlet valves (A), - wherein each wheel connection (R) of the first group is connected to the first brake fluid reservoir (16) via a respective outlet valve (A), - wherein each wheel connection (R) of the second group is connected to the second brake fluid reservoir (26) via a respective outlet valve (A). [11] Braking system (5) according to claim 10, - wherein the master brake cylinder (14) is connected on the suction side to both the first brake fluid reservoir (16) and the second brake fluid reservoir (26). [12] Braking system (5) according to claim 10 and according to claim 3 or a claim dependent thereon, - wherein the master brake cylinder (14) is connected on the suction side to the first brake fluid reservoir (16) and not to the second brake fluid reservoir (26), and / or - wherein the additional brake cylinder (24) is connected on the suction side to the second brake fluid reservoir (26) and not to the first brake fluid reservoir (16). [13] Braking system (5) according to one of claims 10 to 12, - wherein the first electrical pressure generator (12) is connected on the suction side to the first brake fluid reservoir (16) and not to the second brake fluid reservoir (26), and / or - wherein the second electrical pressure generator (22) is connected on the suction side to the second brake fluid reservoir (26) and not to the first brake fluid reservoir (16). [14] Motor vehicle, comprising - a braking system (5) according to one of the preceding claims, - a brake pedal (15) which is coupled to the master brake cylinder (14), - a number of wheel brakes (B) connected to the wheel connections (R) of the braking system (5). [15] Motor vehicle according to claim 14, - wherein the motor vehicle has a first wheel brake (B1), a second wheel brake (B2), a third wheel brake (B3) and a fourth wheel brake (B4), - wherein the first wheel brake (B1) is assigned to a front wheel and the second wheel brake (B2) is assigned to a diagonally opposite rear wheel, - wherein the third wheel brake (B3) is assigned to a front wheel and the fourth wheel brake (B4) is assigned to a diagonally opposite rear wheel, - wherein the third wheel brake (B3) and the fourth wheel brake (B4) are connected to the wheel connections (R3, R4) of the first group, and - wherein the first wheel brake (R1) and the second wheel brake (R2) are connected to the wheel connections (R1, R2) of the second group.

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