Brake system for a vehicle

Integrating a sensor within the hydraulic unit of a brake system simplifies design and reduces costs by eliminating the need for a separate cable connection, enhancing the efficiency and cost-effectiveness of brake system components.

WO2026037532A1PCT designated stage Publication Date: 2026-02-19ROBERT BOSCH GMBH
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Patent Information

Application Number
PCT/EP2025/067389
Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Priority Date
2024-08-13
Filing Date
2025-06-20
Publication Date
2026-02-19

AI Technical Summary

Technical Problem

Existing brake systems require a separate level sensor connected via a cable to a reservoir, increasing complexity and cost.

Method used

Integrate a sensor arrangement within the hydraulic unit to detect hydraulic fluid level, eliminating the need for a separate cable and allowing for a smaller, more cost-effective reservoir design.

Benefits of technology

Simplifies reservoir design, reduces assembly effort, and lowers costs by integrating the sensor directly into the hydraulic unit.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention relates to a brake system (1) for a vehicle, comprising a hydraulic unit (3), which is designed to receive components of a hydraulic circuit (7), a storage container (5), which stores a hydraulic fluid and is fluidically coupled to the hydraulic circuit (7), and a sensor assembly (10), which is integrated in the hydraulic unit (3) and is designed to detect a fill level of the hydraulic fluid in the hydraulic circuit (7), the sensor assembly (10) comprising a receiving chamber (12), which is fluidically connected to the storage container (5) and to the hydraulic circuit (7), a float (14) which is located in the receiving chamber (12), bears a measuring transducer (16) and moves within the receiving chamber (12) depending on the fill level of the hydraulic fluid in the hydraulic circuit (7), and a fill level sensor (18) which detects the movement of the measuring transducer (16) and outputs an output signal representing the fill level of the hydraulic fluid in the hydraulic circuit (7) to an evaluation and control unit (20).
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Description

[0001] R. 410667

[0002] - 1 -

[0003] Description

[0004] title

[0005] Braking system for a vehicle

[0006] The invention relates to a braking system for a vehicle.

[0007] From the prior art, brake systems for vehicles are known which generally include a hydraulic unit designed to accommodate components of a hydraulic circuit, a reservoir which stores hydraulic fluid and is fluidically coupled to the hydraulic circuit, and a level sensor which is located in the reservoir and is electrically connected via an additional connecting cable. The level sensor can detect when there is too little hydraulic fluid in the brake system due to leakage.

[0008] Disclosure of the invention

[0009] The braking system for a vehicle with the features of independent claim 1 has the advantage that a sensor arrangement, designed to detect the fill level of a hydraulic fluid in a hydraulic circuit of the braking system, is integrated into the hydraulic unit. This simplifies the design of a reservoir for the hydraulic unit. The reservoir can thus preferably be smaller and manufactured more cost-effectively. Furthermore, an additional connecting cable attached to the reservoir can be omitted. This results in lower costs and reduced assembly effort.

[0010] Embodiments of the invention provide a braking system for a vehicle, comprising a hydraulic power unit designed to accommodate components of a hydraulic circuit, and a reservoir containing a hydraulic fluid. R. 410667

[0011] - 2 - stores and is fluidically coupled to the hydraulic circuit, and a sensor arrangement is available which is integrated into the hydraulic unit and is designed to detect the level of the hydraulic fluid in the hydraulic circuit. The sensor arrangement comprises a receiving chamber fluidically connected to the reservoir and the hydraulic circuit, a float located in the receiving chamber which carries a measuring transducer and moves within the receiving chamber depending on the level of the hydraulic fluid in the hydraulic circuit, and a level sensor which detects the movement of the measuring transducer and outputs a signal representing the level of the hydraulic fluid in the hydraulic circuit to an evaluation and control unit.

[0012] In this context, the term "evaluation and control unit" can be understood as an electrical device, such as a control unit, particularly a brake system control unit, which processes or evaluates acquired sensor signals. The evaluation and control unit can have at least one interface, which may be implemented in hardware and / or software. In the case of a hardware-based implementation, the interfaces may, for example, be part of a so-called system ASIC, which incorporates various functions of the evaluation and control unit. However, it is also possible that the interfaces are separate integrated circuits or consist at least partially of discrete components. In the case of a software-based implementation, the interfaces may be software modules that are present, for example, on a microcontroller alongside other software modules.A computer program product with program code stored on a machine-readable medium such as semiconductor memory, hard disk memory or optical memory, and used to perform the evaluation when the program is executed by the evaluation and control unit, is also advantageous.

[0013] The measures and further developments listed in the dependent claims enable advantageous improvements to the braking system for a vehicle specified in independent claim 1.

[0014] A particular advantage is that the hydraulic unit can include a hydraulic block. Components of the R. 410667 can be attached to the hydraulic block.

[0015] - 3 -

[0016] The sensor assembly can be attached to the hydraulic circuit and its fluid channels can be integrated. Additionally, the mounting space can be a bore in the hydraulic block of the hydraulic unit. This allows for a particularly cost-effective integration of the sensor assembly into the hydraulic circuit of the brake system.

[0017] In an advantageous embodiment of the brake system, the reservoir can be located outside the hydraulic block of the hydraulic power unit. Alternatively, the reservoir can be integrated into the hydraulic block of the hydraulic power unit. For this purpose, additional volume can be provided within the hydraulic block. This eliminates the need for additional fluid lines outside the hydraulic block that would otherwise connect the reservoir to the hydraulic circuit.

[0018] In a further advantageous embodiment of the brake system, the reservoir can have a lid in which a pressure equalization element is incorporated. Preferably, the pressure equalization element can be designed as a diaphragm. Such a pressure equalization element allows the pressure in the reservoir to be kept constant relative to the environment.

[0019] In a further advantageous embodiment of the brake system, the fluid level sensor can send an output signal to the evaluation and control unit when the level of the hydraulic fluid in the hydraulic circuit falls below a predefined threshold. By sending this output signal, the vehicle user can then be notified, for example via a visual and / or audible signal, that hydraulic fluid needs to be added to the reservoir or that the vehicle should be taken to a workshop for inspection.

[0020] In a further advantageous embodiment of the brake system, the level sensor can be electrically connected to the evaluation and control unit via an electrical contact arrangement. This electrical contact arrangement can, for example, comprise at least one plug-in connection, at least one spring-loaded connection, or at least one insulation displacement connection. This allows the level sensor to be connected directly during the mounting of the R. 410667.

[0021] - 4 -

[0022] The evaluation and control unit or the control device on the hydraulic block are electrically contacted.

[0023] In a further advantageous embodiment of the braking system, the sensor can be designed as a permanent magnet and the level sensor as a magnetic field sensor, which can detect a change in the magnetic field at the level sensor caused by the movement of the float with the sensor. The float moves with the level of the hydraulic fluid in the hydraulic circuit and thus changes the magnetic field at the level sensor. If the level of the hydraulic fluid falls below the predefined threshold, the output signal of the level sensor, which is sent to the evaluation and control unit, can change.

[0024] Exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description. In the drawings, identical reference numerals denote components or elements that perform the same or analogous functions.

[0025] Brief description of the drawings

[0026] Fig. 1 shows a schematic block representation of a first embodiment of a braking system according to the invention for a vehicle.

[0027] Fig. 2 shows a schematic partial sectional view of the braking system according to the invention for a vehicle from Fig. 1 .

[0028] Fig. 3 shows a schematic block representation of a second embodiment of a braking system according to the invention for a vehicle.

[0029] Fig. 4 shows a schematic partial sectional view of the braking system according to the invention for a vehicle from Fig. 3.

[0030] Embodiments of the invention R. 410667

[0031] - 5 -

[0032] As can be seen from Figs. 1 to 4, the illustrated embodiments of a brake system 1 according to the invention for a vehicle each comprise a hydraulic unit 3, which is designed to accommodate components of a hydraulic circuit 7, a reservoir 5, which stores a hydraulic fluid and is fluidically coupled to the hydraulic circuit 7, and a sensor arrangement 10, which is integrated into the hydraulic unit 3 and is designed to detect a fill level of the hydraulic fluid in the hydraulic circuit 7.The sensor arrangement 10 comprises a receiving chamber 12 fluidically connected to the reservoir 5 and to the hydraulic circuit 7, a float 14 arranged in the receiving chamber 12 which carries a measuring transmitter 16 and moves within the receiving chamber 12 depending on the fill level of the hydraulic fluid in the hydraulic circuit 7, and a level sensor 18 which detects the movement of the measuring transmitter 16 and outputs a signal representing the fill level of the hydraulic fluid in the hydraulic circuit 7 to an evaluation and control unit 20.

[0033] In the illustrated embodiments of the brake system 1, the hydraulic unit 3 comprises a hydraulic block 3A. Components of the hydraulic circuit 7 are attached to the hydraulic block 3A, and fluid channels of the hydraulic circuit 7 (not specified in detail) are incorporated into it. Figures 1 to 4 show, by way of example, a pump 7.1, a hydraulic valve 7.2, and a pressure sensor 7.3 attached to the hydraulic block 3A. The pump 7.2 is also fluidically coupled to a pressure equalization element 3.1. In the illustrated embodiments of the brake system 1, the receiving chamber 12 for the float 14 is provided as a bore 12A in the hydraulic block 3A of the hydraulic unit 3.

[0034] As can be seen from Figs. 1 and 3, in the illustrated embodiments of the brake system 1, a brake actuator 9 designed as a brake caliper 9A is fluidically connected to the hydraulic circuit 7 of the hydraulic unit 3.

[0035] As can be seen from Figs. 1 and 2, in the illustrated first embodiment of the brake system 1A, the sensor arrangement 10A is integrated into the hydraulic block 3A of the hydraulic unit 3, and the reservoir 5 is R. 410667

[0036] - 6 - is located outside the hydraulic block 3A of the hydraulic unit 3. The reservoir 5 is fluidically connected to the hydraulic circuit 7 and the receiving chamber 12 via a fluid line (not otherwise specified). The fluid line is located at least partially outside the hydraulic block 3A.

[0037] As can be seen from Figures 3 and 4, in the illustrated second embodiment of the brake system 1B, the sensor arrangement 10B and the reservoir 5 are integrated into the hydraulic block 3A of the hydraulic unit 3. The reservoir 5 is fluidically connected to the hydraulic circuit 7 and the receiving chamber 12 via a fluid channel (not shown in detail) incorporated into the hydraulic block 3A.

[0038] As can be seen from Figures 1 to 4, the reservoir 5 in both illustrated embodiments of the brake system 1 has a lid 5.1 in which a pressure equalization element 5.2 is inserted. The pressure equalization element 5.2 is designed as a diaphragm.

[0039] As can be seen particularly in Figures 2 and 4, the level sensor 18 in the illustrated embodiments of the brake system 1 is electrically connected to the evaluation and control unit 20 via an electrical contact arrangement 19. In the illustrated embodiments, the electrical contact arrangement 19 has two plug-in connections through which the level sensor 18 is electrically connected to a circuit board 22 of the evaluation and control unit 20. The circuit board 22 carries electrical components of the evaluation and control unit 20 (not shown), such as discrete electronic components and integrated circuits, and is electrically connected to a higher-level electrical unit (not shown) via a multi-core connecting cable 24.

[0040] In embodiments of the brake system 1 not shown, the electrical contact arrangement 19 has at least one spring contact connection or at least one insulation displacement connection.

[0041] In the illustrated embodiments of the brake system 1, the measuring transmitter 16 is a permanent magnet 16A and the level sensor 18 is an R. 410667

[0042] - 7 -

[0043] The magnetic field sensor 18A is implemented. Here, the measuring transmitter 16, designed as a permanent magnet 16A, generates a magnetic field, and the level sensor 18, also designed as a magnetic field sensor 18A, detects a change in this magnetic field at the level sensor caused by the movement of the float 14 with the measuring transmitter 16. The level sensor 18 provides the following information in the illustrated diagrams.

[0044] In exemplary embodiments of the brake system 1, the output signal is sent to the evaluation and control unit 20 when the level of the hydraulic fluid in the hydraulic circuit 7 falls below a predetermined threshold.

Claims

R. 410667 - 8 - Claims 1. Braking system (1) for a vehicle, comprising a hydraulic power unit (3) designed to accommodate components of a hydraulic circuit (7), a reservoir (5) which stores a hydraulic fluid and is fluidically coupled to the hydraulic circuit (7), and a sensor arrangement (10) which is integrated into the hydraulic power unit (3) and is designed to detect the level of the hydraulic fluid in the hydraulic circuit (7), wherein the sensor arrangement (10) comprises a receiving chamber (12) fluidically connected to the reservoir (5) and to the hydraulic circuit (7), a float (14) arranged in the receiving chamber (12) which carries a measuring transmitter (16) and moves within the receiving chamber (12) depending on the level of the hydraulic fluid in the hydraulic circuit (7), and a level sensor (18).which detects the movement of the sensor (16) and outputs a signal representing the level of the hydraulic fluid in the hydraulic circuit (7) to an evaluation and control unit (20).

2. Brake system (1) according to claim 1 , characterized in that the hydraulic unit (3) comprises a hydraulic block (3A) wherein components of the hydraulic circuit (7) are attached to the hydraulic block (3A) and fluid channels of the hydraulic circuit (7) are provided.

3. Brake system (1) according to claim 2, characterized in that the receiving space (12) is provided as a bore (12A) in the hydraulic block (3A) of the hydraulic unit (3).

4. Brake system (1) according to claim 2 or 3, characterized in that the reservoir (5) is arranged outside the hydraulic block (3A) of the hydraulic unit (3) or is integrated into the hydraulic block (3A) of the hydraulic unit (3). R. 410667 - 9 - 5. Brake system (1) according to one of claims 1 to 4, characterized in that the reservoir (5) has a lid (5.1) in which a pressure equalization element (5.2) is inserted.

6. Brake system (1) according to one of claims 1 to 5, characterized in that the level sensor (18) outputs the output signal to the evaluation and control unit (20) when the level of the hydraulic fluid in the hydraulic circuit (7) falls below a predetermined threshold value.

7. Brake system (1) according to one of claims 1 to 6, characterized in that the level sensor (18) is electrically connected to the evaluation and control unit (20) via an electrical contact arrangement (19).

8. Braking system (1) according to claim 7, characterized in that the electrical contact arrangement (19) has at least one plug contact connection or at least one spring contact connection or at least one insulation displacement connection.

9. Braking system (1) according to one of claims 1 to 8, characterized in that the measuring transmitter (16) is designed as a permanent magnet (16A) and the level sensor (18) is designed as a magnetic field sensor (18A), which detects a change in a magnetic field at the level sensor (18) caused by the movement of the float (14) with the measuring transmitter (16).

Citation Information

Patent Citations

  • Measuring device for equalizing-container in hydraulic or electrohydraulic brake system has continuously variable measurement of liquid level using float and sensor

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