HYDRAULIC BLOCK FOR A HYDRAULIC UNIT OF A VEHICLE HYDRAULIC BRAKING SYSTEM
Patent Information
- Authority / Receiving Office
- MX · MX
- Patent Type
- Patents
- Current Assignee / Owner
- ROBERT BOSCH GMBH
- Filing Date
- 2022-05-25
- Publication Date
- 2026-06-12
AI Technical Summary
Existing hydraulic blocks for vehicle braking systems lack efficient mechanisms for generating braking pressure using external power, particularly in slip-controlled systems, and do not effectively integrate hydraulic components for anti-lock and driving dynamics control.
A parallelepiped-shaped hydraulic block with an external power cylinder bore and guide bushing for an axially displaceable piston, driven by an electric motor and planetary gear, integrated with hydraulic components like solenoid valves and accumulators, allowing for mechanical clamping and hydraulic connection, and featuring a guide bushing for low-friction movement.
Enables efficient generation of braking pressure using external power, integrates hydraulic components for anti-lock and driving dynamics control, and ensures low-friction, wear-resistant operation of the piston, enhancing the reliability and performance of the braking system.
Smart Images
Figure MX434874B0
Abstract
Description
HYDRAULIC BLOCK FOR A HYDRAULIC UNIT OF A VEHICLE HYDRAULIC BRAKING SYSTEM FIELD OF INVENTION The invention relates to a hydraulic block for a hydraulic unit of a vehicle hydraulic braking system, in particular a vehicle hydraulic braking system, slip-controlled and / or externally powered, with the characteristics of the generic term of claim 1. BACKGROUND OF THE INVENTION Open publication DE 10 2016 202 113 A1 discloses a narrow, parallelepiped-shaped hydraulic block for a hydraulic unit of a hydraulically controlled, externally powered vehicle braking system. A master brake cylinder bore is continuously mounted from one opposite narrow side, and an external power cylinder bore, perpendicular to the master brake cylinder bore, is also continuously mounted through two opposite large sides of the hydraulic block. The block also includes a blind hole for a pedal path simulator. A cylinder bushing, closed at one end and protruding from one side of the hydraulic block, is fitted to the external power cylinder bore and accommodates an axially displaceable external power piston.To generate externally powered braking pressure, the externally powered piston is driven by an electric motor via a ball screw in the cylinder hub. The electric motor is mounted coaxially with the externally powered cylinder bore outside the hydraulic block, and the ball screw is also coaxially positioned with the electric motor and the externally powered cylinder bore, between the electric motor and the externally powered piston. The electric motor and ball screw together form an externally powered drive unit and, along with the externally powered piston, cylinder hub, and externally powered cylinder bore, constitute an externally powered braking pressure generator for the vehicle's hydraulic braking system. BRIEF DESCRIPTION OF THE INVENTION The hydraulic unit according to the invention, with the features of claim 1, is provided for a hydraulic unit of a vehicle hydraulic braking system, in particular an externally powered and / or skid-controlled vehicle hydraulic braking system. The hydraulic unit has a hydraulic block, particularly in the form of a parallelepiped, to which hydraulic wheel brakes of the vehicle braking system can be connected via brake cables. The skid controls are, in particular, anti-lock braking, anti-slip, and / or driving dynamics / electronic stability program controls, for which the abbreviations ABS, ASR, and / or FDR / ESP are used. The latter are also colloquially known as anti-slip controls. The skid controls are known and are not explained in detail here. The hydraulic block provides mechanical support and hydraulic connection for the hydraulic components of a vehicle's braking or traction control system. These hydraulic components include solenoid valves, check valves, hydraulic accumulators, damping chambers, and pressure sensors. The hydraulic components are held in receptacles within the hydraulic block, which are generally cylindrical passages or blind holes, sometimes with diameter markings. "Connected" means that the receptacles or the hydraulic components held within them are connected by cables within the hydraulic block according to a hydraulic circuit diagram of the vehicle's braking or traction control system. However, the cables are not usually drilled through the hydraulic block. Equipped with the hydraulic components of the vehicle's braking system or its skid control, the hydraulic block forms the hydraulic unit, where "equipped" means that the hydraulic components are held in the receptacles of the hydraulic block proposed for them in each case. The hydraulic block according to the invention has an external power cylinder bore in which an external power piston, often also known as a plunger piston, can be axially displaced. For radial guidance of the external power piston, the hydraulic block according to the invention has a guide bushing that is fixed in the external power cylinder bore, surrounds the external power piston, and guides it axially within the external power cylinder bore. The invention allows, for example, a wear-resistant and / or low-friction guide for the external power piston made of a material different from the hydraulic block. For externally powered brake pressure generation, the externally powered piston can be moved, for example, by an electric motor via a threaded drive or by another rotation / translation gear in the externally powered cylinder bore. A mechanical speed reduction gear can be provided between the electric motor and the threaded drive. The electric motor and the threaded drive together form an electromechanical external power drive for the externally powered piston and, together with the externally powered piston and the externally powered cylinder bore, an electromechanical externally powered brake pressure generator, wherein the invention does not exclude other externally powered brake pressure generators that are not electromechanical. A master brake cylinder bore in the hydraulic block is not required for the invention, although a master brake cylinder bore is preferably provided in the hydraulic block. The master brake cylinder bore is provided for one or more pistons of a master brake cylinder for a muscle-powered or auxiliary actuation of the vehicle braking system; that is, one of the pistons can be mechanically moved by means of a brake pedal (foot) or a brake lever (hand) in the master brake cylinder bore. Whenever the hydraulic block has a master brake cylinder bore, it preferably also has a simulator cylinder bore for a pedal path simulator, in which a spring- or gas-pressure-actuated simulator piston, for example, is axially displaceable. The pedal path simulator is preferably connected to the master brake cylinder via a solenoid valve, also known as a simulator valve, and serves to receive brake fluid from the master brake cylinder bore when the master brake cylinder is hydraulically isolated from the vehicle's braking system by closing a bypass valve, such that no brake fluid can be drawn from the master brake cylinder into the vehicle's braking system.The pedal path simulator allows displacement of the master brake cylinder piston in the event of an external power actuation of the vehicle's braking system. Through holes or blind holes known here as “holes” or “cylinder holes” can also be produced in a way other than drilling. Dependent claims relate to further developments and advantageous embodiments of the invention specified in the independent claim. All the features described in the description and figure can be realized individually or in virtually any combination in embodiments of the invention. Embodiments of the invention that do not have all, but only one or more, features of a claim or an embodiment of the invention are fundamentally possible. BRIEF DESCRIPTION OF THE FIGURE The invention is explained in more detail below with reference to an embodiment shown in the figure. Figure 1 shows a section of a hydraulic block axially through an external power cylinder bore of a hydraulic unit according to the invention. DETAILED DESCRIPTION OF THE INVENTION The hydraulic unit 1 shown in Figure 1, according to the invention, is proposed for generating pressure in an externally powered hydraulic braking system of a vehicle that has a slip control system. These slip controls are, for example, anti-lock braking systems, anti-roll bars, and / or driving dynamics / electronic stability programs, for which the abbreviations ABS, ASR, FDR / ESP are used. The hydraulic unit 1 according to the invention has a hydraulic block 2, which serves for mechanical clamping and hydraulic connection of hydraulic components and other skid control components, such as solenoid valves, check valves, hydraulic accumulators, and damping chambers. The components are arranged on and within the hydraulic block 1 and are hydraulically connected to each other by means of an unmarked pin on the hydraulic block 2 that corresponds to a hydraulic circuit diagram of the externally powered vehicle braking and skid control system. Two solenoid valves 27 are shown as examples, indicating switching. In the embodiment of the invention represented and described, the hydraulic block 2 is a flat metal block in the shape of a parallelepiped made of, for example, an aluminum alloy, which is provided with holes to receive the components and is drilled according to the hydraulic circuit diagram of the vehicle braking system and skid control. The hydraulic block 2 has a through-hole perpendicular to two large opposite sides of the hydraulic block 2, serving as the external power cylinder bore 3, into which an external power piston 4 is axially displaceable. For axially displaceable guidance of the external power piston 4, a guide duct 5 is fixed axially in the external power cylinder bore 3, which guides the external power piston 4 radially in the external power cylinder bore 3. In the example configuration, the guide duje 5 is made of plastic. Externally, the guide duje 5 is sealed by a press-fit seat in the external power cylinder bore 3 of the hydraulic block 2. Inside, the guide bushing 5 has a circumferential sealing groove 6, in which a sealing ring is arranged as the first piston seal 7. The first piston seal 7, which can also be taken as a high-pressure seal for the external power piston 4, seals between the external power piston 4 and the guide bushing 5. An annular passage 8 of the external power cylinder bore 3 is axially connected to the guide bushing 5, thereby reducing the diameter of the external power cylinder bore 3 to a smaller diameter than in the area of the guide bushing 5. The annular passage 8 is axially distanced from the guide bushing 5, forming a circumferential groove in which a second piston seal 9 is fitted, which can also be considered a low-pressure seal. The second piston seal 9 is axially retained between the guide bushing 5 and the annular passage 8 of the external power cylinder bore 3. It seals between the external power cylinder bore 3 and the external power piston 4. Axially at the level of the guide bushing 5, a brake fluid cable 10 in the hydraulic block 2 leads to the external power cylinder port 3. In the example embodiment, the brake fluid cable 10 runs between the first and second piston seals 7, 9 to the external power cylinder port 3. The guide bushing 5 has a channel 11 leading from the junction of the brake fluid port 10 to a front side of the guide bushing 5 facing the annular passage 8, such that the brake fluid cable 10 communicates with the second piston seal 9 through the channel 11 on a front side facing the guide bushing 5. The channel 11 can be, as shown, for example, an axially parallel groove in an outer circumference of the guide bushing 5 or a hole extending from the outer circumference to the front surface of the guide bushing 5 facing the annular step 8 (not shown).The guide bushing 5 is arranged rotated in the external power cylinder bore 3 such that its channel 11 communicates with the brake fluid cable 10. The brake fluid cable 10 communicates with a brake fluid storage reservoir not shown and causes lubrication of an outer circumference of the external power piston 4 in the area of the second piston seal 9. In an axial movement, the brake fluid on the outer circumference of the external power piston 4 also reaches the first piston seal 7, such that both piston seals 7, 9 are lubricated. On the outside, the guide bushing 5 has a circumferential groove 12, which is interrupted at the channel 11 and terminates on both sides at a distance from the channel 11, such that the groove 12 does not communicate with the channel 11. The brake fluid cables 13 lead to the external power cylinder bore 3 axially at the height of the groove 12 on the outer circumference of the guide bushing 5 at two circumferential positions, which communicate with each other through the groove 12. In this way, the two brake fluid cables 13, which connect the hydraulic components of the external power vehicle's skid control system, are externally connected around the external power cylinder bore 3.In the exemplary embodiment of the invention, the two brake fluid cables 13 are located outside the cross-sectional plane, so one of the two brake fluid cables 13 is shown rotated in the cross-sectional plane. The other brake fluid cable 13 is not visible in the figure. The external power cylinder bore 3, which passes through the hydraulic block 2, is closed at one end by a basin-shaped cylinder cover 14. In the example, this cover is screwed into the external power cylinder bore 3. Alternatively, for example, it can be secured with a spring washer, which engages externally in a circumferential groove on the inside of the external power cylinder bore 3 and internally in a circumferential groove on the outside of the cylinder cover 14 (not shown). The cylinder cover 14 projects outward from the hydraulic block 2, extending the external power cylinder bore 3 and thus providing a travel path for the external power piston 4. Cylinder cover 14 is a crown cover with a rim having radial recesses, with which it retains the guide bushing 5 axially in the external power cylinder bore 3. Brake fluid can re-enter through the radial recesses. Outside the guide bushing 5, the external power cylinder bore 3 has a larger diameter than the external power piston 4, such that there is a ring gap 15 between the external power piston 4 and the external power cylinder bore 3. Similarly, the cylinder cover 14 has a larger inner diameter than the external power piston 4, such that there is also a ring gap 16 between the external power piston and the cylinder cover 14. As a result, the external power piston 4 is guided radially exclusively in the guide bushing 5. To move the external power piston 4 in the external power cylinder bore 3 to generate externally powered braking pressure, the hydraulic unit 1 has an electric motor 17 that moves the external power piston 4 via a planetary gear set 18 as a speed reduction gear and a ball screw 19 in the external power cylinder bore 3. The ball screw 19 can also be generally described as a helical gear or a rotary / translational conversion gear. The ball screw 19 is arranged coaxially with respect to the external power piston 4 and with respect to the external power cylinder bore 3, partially within the external power piston 4, which is designed for this purpose as a hollow piston. The ball screw 19 is mounted with a ball bearing 20, which is secured outside the hydraulic block 2 with a tubular bearing retainer 21.The planetary gear 18 is also arranged coaxially with respect to the external power cylinder bore 3 and with respect to the external power piston 4 between the ball screw 19 and the electric motor 17. The electric motor 17 has a motor housing 22, which is also screwed coaxially to the external power cylinder bore 3 and the external power piston 4 on the outside of the hydraulic block 2. The electric motor 17, the planetary gear 18, and the ball screw 19 form an external power electromechanical drive 23, by which the external power piston 4 can be axially displaced to generate braking pressure for the externally powered vehicle braking system in the external power cylinder bore 3.Together with the external power cylinder bore 3, the cylinder cover 14, and the external power piston 4, the external power drive 23 forms an external power brake pressure generator 24 of the hydraulic unit 1 according to the invention. The invention does not exclude other external power generation of brake pressure other than electromechanical. In the represented and described embodiment of the invention, the hydraulic block 2 has a master brake cylinder bore 25 in which a master brake cylinder piston (not shown) can be mounted. This piston can be mechanically moved via a piston rod by means of a foot brake pedal (not shown) or a handbrake lever in the master brake cylinder bore 25. Furthermore, the hydraulic block 2 has a simulator cylinder bore 26 for a simulator piston (not shown), e.g., spring-loaded. Brake fluid can be drawn from the master brake cylinder bore 25 into the simulator cylinder bore 26 in the event of external power actuation of the vehicle's braking system, in order to move the master brake cylinder piston in the master brake cylinder bore 25.In addition to the external power brake pressure generator 24, the vehicle braking system can also be powered by muscle power with the displacement of the main brake cylinder piston in the main brake cylinder bore 25, which is provided in particular in case of malfunction or failure of the external power brake pressure generator 24. The external power cylinder hole 3, the main brake cylinder hole 25 and / or the simulator cylinder hole 26 can also be produced differently from drilling.
Claims
NOVELTY OF THE INVENTION Having described the present invention, the following claims are considered novel and are therefore claimed as property. CLAIMS 1. Hydraulic block for a hydraulic unit of a hydraulic vehicle braking system, with an external power brake cylinder bore in which an external power piston can be axially displaced, characterized in that a guide bushing is arranged in the external power brake cylinder bore, which guides the external power piston radially in the external power brake cylinder bore.
2. Hydraulic block according to claim 1, characterized in that the guide bushing has a circumferential sealing groove on its inner circumferential surface, in which a first piston seal is arranged, which seals between the external power piston and the guide bushing.
3. Hydraulic block according to claim 1 or 2, characterized in that the external power cylinder bore has an annular passage on a front side of the guide bushing, in which a second piston seal is fixed, which is axially retained in the annular passage by the guide bushing.
4. Hydraulic block according to claim 3, characterized in that, at the height of the guide hub, a brake fluid cable leads axially to the external power cylinder bore and in that the guide hub has a channel leading from the brake fluid cable to the annular passage of the external power cylinder bore on a front side of the guide hub.
5. Hydraulic block according to one or more of the preceding claims, characterized in that the guide bushing has a circumferential groove on the outside and in that, at the height of the outer circumferential groove of the guide bushing, in two circumferential positions, the brake fluid cables run axially into the external power cylinder bore, communicating with each other through the outer circumferential groove of the guide bushing.
6. Hydraulic block according to one or more of the preceding claims, characterized in that the external power cylinder bore passes through the hydraulic block and one end of the external power cylinder bore is closed with a cylinder cover that protrudes from the hydraulic block and axially extends the external power cylinder bore.
7. Hydraulic block according to one or more of the preceding claims, characterized in that outside the guide bushing there is a ring gap between the external power piston and the external power cylinder bore and / or a ring gap between the external power piston and the cylinder cover. i zconn / zznz / E / YiAi 8. Hydraulic block according to one or more of the preceding claims, characterized in that an external power drive for the external power piston is arranged in the hydraulic block at a junction of the external power cylinder bore, by which the external power piston can be moved to generate a braking pressure in the external power cylinder bore.
9. Hydraulic block according to one or more of the preceding claims, characterized in that the hydraulic block has a main brake cylinder bore and / or a simulator cylinder bore.