Distributed electro-hydraulic brake unit
By setting up a distributed electro-hydraulic braking unit at the wheels, the piston is automatically retracted by hydraulic pressure and elastic parts, the friction and noise problems in the central electro-hydraulic braking system are solved, and low friction, low noise and high-efficiency braking are achieved. Reduces system weight and cost.
Patent Information
- Application Number
- CN202410838920.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-07-03
- Filing Date
- 2024-06-26
- Publication Date
- 2025-01-03
AI Technical Summary
The central electro-hydraulic braking system of existing vehicles has friction and wear during braking, resulting in energy loss and noise, and has high system complexity and cost.
Using a distributed electro-hydraulic brake unit, by setting a brake caliper and piston at each wheel, brake is achieved using hydraulic pressure, and the piston is connected to the elastic member to achieve automatic retraction and compression force preloading, reducing friction and noise, and Drive the brake caliper pistons with a small electric motor to reduce system weight and cost.
Low friction and noise reduction after the braking process is achieved, energy loss and weight of the brake system are reduced, driving comfort is improved, and braking pressure is precisely adjusted through pressure sensors, reducing system complexity and cost.
Smart Images
Figure CN119239532A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a distributed electro-hydraulic brake unit for braking the wheels of a motor vehicle. In addition, the invention also relates to a motor vehicle having such a distributed electro-hydraulic brake unit. Background Art
[0002] In today's vehicle configurations, central brake systems can be used economically and conveniently. With the increasing electrification of vehicles, the trend is towards new brake system concepts. In particular, the brakes should be designed, for example, in the form of a front axle module and a rear axle module or even in the form of four individual brake modules for the wheels. Such brake systems are here referred to as distributed brake systems.
[0003] Patent document US Pat. No. 4,406,352 discloses an electrically operated disc brake device for a vehicle. The disc brake device comprises a brake caliper in which a spindle drive assembly is arranged. The spindle nut works together with the brake cylinder to press the brake lining against the brake disc. A spring is arranged between one end of the spindle of the spindle drive assembly and a shoulder of the brake cylinder, and the brake cylinder is separated from the brake disc by the spring after the braking process to achieve a zero resistance function. Summary of the invention
[0004] The object of the present invention is to provide an improved distributed electro-hydraulic brake unit.
[0005] This object is achieved by a decentralized electrohydraulic brake unit having the subject matter of claim 1. Preferred embodiments are disclosed in the dependent claims.
[0006] The invention provides a distributed electro-hydraulic brake unit for braking the wheels of a motor vehicle. The brake unit comprises a brake caliper and a brake caliper piston which can be axially moved in the brake caliper by a drive device, by which hydraulic pressure can be applied to the brake piston, wherein a brake lining is arranged at the brake piston. The brake caliper piston and the brake piston are connected to each other by an elastic element, by which the brake piston can be actively retracted after the braking process.
[0007] In contrast to central electrohydraulic brake units, distributed brake units generate brake pressure at each wheel. This eliminates the need for laying hydraulic lines. In the brake unit, the brake pressure is applied via the caliper piston. By retracting the caliper piston, the brake pressure can be reduced after the braking process. The brake piston is retracted in the same way via an elastic element connected to the brake piston and the caliper piston. As a result, the brake piston can be separated directly from the brake disc after the braking process. This avoids friction of the brake lining on the brake disc and prevents wear and energy losses caused by this.
[0008] In a preferred embodiment of the invention, the diameter of the brake piston is greater than the diameter of the brake caliper piston. As a result, the axial displacement of the brake caliper piston is greater than the axial displacement of the brake piston. The pulling force caused by the elastic element is thereby increased. Although a high braking force is generated at the brake piston, the force at the brake caliper piston is significantly less than this braking force. As a result, a smaller motor can be used to drive the brake caliper piston. As a result, the weight of the unsprung wheel can be reduced and driving comfort can be improved.
[0009] In another preferred embodiment of the invention, the diameter of the caliper piston is 8 to 15 mm and the diameter of the brake piston is 20 to 60 mm. Such diameters of the caliper piston are suitable for very small and cost-effective electric motors with a torque of less than 1 Nm. As a result, the forces exerted on the caliper piston are very low, so that plastic materials can be used for the drive unit due to the low load on the spindle. In addition, the tolerance requirements on the components are less stringent.
[0010] Preferably, a pressure chamber is arranged between the brake caliper piston and the brake piston, and a pressure sensor is provided, by which the pressure in the pressure chamber can be measured. Thus, the brake pressure generated by the brake caliper piston can be measured. Thus, the brake pressure can be precisely adjusted.
[0011] In an advantageous development, the elastic element is a spring. The advantage of a spring is that it can exert not only tensile forces but also compressive forces. In addition to the fact that the brake piston can be actively retracted after a braking operation, the brake piston can also be preloaded by the spring during a braking operation. As a result, the brake lining can be quickly pressed against the brake disc. The brake lining is therefore constantly subjected to either tensile forces or compressive forces. As a result, rattling of the brake lining can be prevented, thereby reducing the noise generated by braking.
[0012] Advantageously, the elastic element is designed such that the brake piston is preloaded in the direction of the brake caliper piston when in the rest position. The brake piston is thus held securely in the rest position. This prevents the brake lining from rattling. This significantly reduces the noise generated by braking.
[0013] In another advantageous embodiment, the brake caliper piston is made of a plastic material. Since no great forces are applied to the brake caliper piston, it can be made of a plastic material. This can reduce the cost and weight of such an electrohydraulic brake unit.
[0014] The present invention also provides a motor vehicle having such a distributed electro-hydraulic brake unit. The motor vehicle has the advantages and characteristics described above. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description.
[0016] in:
[0017] Figure 1 A cross-sectional view of a distributed electro-hydraulic brake unit according to an embodiment of the present invention is shown. DETAILED DESCRIPTION
[0018] Figure 1 A cross-sectional view of a distributed electro-hydraulic brake unit 10 according to an embodiment of the present invention is shown. The brake unit 10 comprises a brake caliper 14 and a brake caliper claw 18 arranged at the brake caliper 14. In the illustrated figure, the brake caliper claw 18 is only partially shown. A drive device 22 configured as an electric motor is arranged at the brake caliper 14, by means of which a brake caliper piston 26 arranged in the brake caliper 14 can be axially displaced. The brake caliper piston 26 is sealed by a brake caliper seal 30. The brake caliper 14 forms a pressure chamber 34, in which a brake piston 38 is arranged in an axially displaceable manner. The pressure chamber 34 is sealed from the outside by a brake piston seal 42 arranged between the brake piston 38 and the brake caliper 14. The pressure chamber 34 is arranged here between the brake caliper piston 26 and the brake piston 38 in the brake caliper 14. The electro-hydraulic brake unit 10 also has a pressure sensor 46, by means of which the pressure in the pressure chamber 34 can be measured. A brake lining 50 is applied to the brake piston 38 , which can come into contact with a brake disk 54 in order to brake the motor vehicle.
[0019] The brake caliper piston 26 and the brake piston 38 are firmly connected to each other via an elastic element 58, which is designed as a spring in the present embodiment. The spring 58 is arranged coaxially with the brake caliper piston 26 and the brake piston 38. In the present embodiment, it can be seen that the diameter D of the brake piston 38 BK Greater than the diameter D of the brake caliper piston 26 BSK Accordingly, the axial movement of the caliper piston 26 is greater than the axial movement of the brake piston 38 .
[0020] Since the axial displacement of the brake piston 38 is different from the axial displacement of the brake caliper piston 26, a tensile force can be applied to the brake piston 38 after the braking process by the spring 58. In the rest position, the brake piston 38 is subjected to a tensile force so that it is firmly held in the rest position. However, during the braking process, a compressive force is applied to the brake piston 38 by the spring 58, so that the brake piston 38 is additionally loaded in the direction of the brake disk 54.
[0021] In the brake caliper 14 , in the region of the caliper piston 26 , a compensation bore 62 is provided, via which pressure changes caused by the caliper piston 26 can be compensated.
Claims
1. A distributed electro-hydraulic brake unit (10) for braking a wheel of a motor vehicle, the distributed electro-hydraulic brake unit comprising a brake caliper (14) and a brake caliper piston (26) which can be axially moved in the brake caliper (14) by a drive device (22), and through which a hydraulic pressure can be applied to a brake piston (38), wherein: A brake lining (50) is arranged on the brake piston (38), wherein the caliper piston (26) and the brake piston (38) are connected to one another via an elastic element (58), via which the brake piston (38) can be actively retracted after a braking process.
2. The distributed electro-hydraulic brake unit (10) according to claim 1, characterized in that: The diameter (D BK ) is larger than the diameter (D BSK ).
3. The distributed electro-hydraulic brake unit (10) according to claim 2, characterized in that: The diameter (D BSK ) is 8 to 15 mm, and the diameter (D BK ) is 20 to 60 mm.
4. A distributed electro-hydraulic brake unit (10) according to any one of the preceding claims, characterized in that: A pressure chamber (34) is arranged between the brake caliper piston (26) and the brake piston (38), and a pressure sensor (46) is provided, by which the pressure in the pressure chamber (34) can be measured.
5. A distributed electro-hydraulic brake unit (10) according to any one of the preceding claims, characterized in that: The elastic member (58) is a spring.
6. A distributed electro-hydraulic brake unit (10) according to any one of the preceding claims, characterized in that: The elastic element (58) is designed such that the brake piston (38) is preloaded in the direction of the brake caliper piston (26) when in the rest position.
7. A distributed electro-hydraulic brake unit (10) according to any one of the preceding claims, characterized in that: The brake caliper piston (26) is made of plastic material.
8. Motor vehicle comprising a distributed electro-hydraulic brake unit (10) according to any one of the preceding claims.