Hydraulic block for hydraulic assembly of hydraulic vehicle brake system

Abstract

The invention proposes that an external force piston (4) of an electromechanical external force brake pressure generator (24) is radially guided by means of a guide bushing (5) in an external force cylinder bore (3) of a hydraulic block (2) of a hydraulic assembly (1) of a hydraulic slip-regulated external force vehicle brake system.

Description

Technical Field

[0001] The invention relates to a hydraulic block for a hydraulic assembly of a hydraulic vehicle brake system, in particular a hydraulic slip-controlled vehicle brake system and / or an externally powered vehicle brake system. Background Art

[0002] Publication DE 102016202113 A1 discloses a narrow rectangular hydraulic block for a hydraulic assembly of a slip-regulated hydraulic external force vehicle brake system, in which the master brake cylinder bore is installed continuously from one side to the opposite narrow side, and the external force cylinder bore perpendicular to the master brake cylinder bore is also installed continuously through two opposite large sides of the hydraulic block. In addition, the known hydraulic block has a blind hole as a receiving part for a pedal travel simulator. A cylinder bushing closed at one end is arranged in the external force cylinder bore, which protrudes from the hydraulic block on one side and in which the external force piston is axially movably accommodated. In order to generate brake pressure using external force, the external force piston can be moved in the cylinder bushing by an electric motor via a ball screw drive mechanism. The electric motor is arranged coaxially with the external force cylinder bore on the outside of the hydraulic block, and the ball screw drive mechanism (also coaxially with the electric motor and the external force cylinder bore) is located between the electric motor and the external force piston. The electric motor and the ball screw drive form an external force drive and, together with an external force piston, a cylinder bushing and an external force cylinder bore, form an external force brake pressure generator for a hydraulic vehicle brake system. Summary of the invention

[0003] The hydraulic assembly according to the invention is provided for a hydraulic assembly of a hydraulic vehicle brake system, in particular a hydraulic externally-forced vehicle brake system and / or a slip-controlled vehicle brake system. The hydraulic assembly has a hydraulic block, in particular a cuboid, to which the hydraulic wheel brakes of the vehicle brake system can be connected via brake lines. The slip control is in particular an anti-lock brake, drive slip and / or driving dynamics control / electronic stability program, for which the abbreviations ABS, ASR and / or FDR / ESP are often used. The latter is also referred to as "anti-slip control". Slip control is known and will not be explained in further detail here.

[0004] The hydraulic block is used to mechanically fix and hydraulically connect hydraulic components of a vehicle brake system or its slip control unit. Such hydraulic components are in particular solenoid valves, non-return valves, hydraulic accumulators, damper chambers and pressure sensors. The hydraulic components are fixed in a receptacle in the hydraulic block, which is mostly configured as a cylindrical through hole or blind hole, some of which have a diameter step. "Connected" means that the receptacle or the hydraulic components fixed therein are connected via a pipeline in the hydraulic block according to the hydraulic circuit diagram of the vehicle brake system or its slip control unit. However, the pipeline is typically not necessarily drilled in the hydraulic block.

[0005] The hydraulic block is equipped with hydraulic components of the vehicle brake system or its slip control system to form a hydraulic assembly, wherein "equipped" means that the hydraulic components are fixed in the respective receptacles of the hydraulic block provided therefor.

[0006] The hydraulic block according to the invention has an external force cylinder bore in which an external force piston, which is also often referred to as a plunger piston, can be axially displaced. In order to radially guide the external force piston, the hydraulic block according to the invention has a guide bushing which is arranged in the external force cylinder bore, surrounds the external force piston and guides the external force piston axially displaceably in the external force cylinder bore. The invention enables, for example, wear-resistant and / or low-friction guidance of an external force piston made of a different material from the hydraulic block.

[0007] In order to generate brake pressure by external force, the external force piston can be moved in the external force cylinder hole by means of an electric motor via a threaded transmission mechanism or by means of other rotation / translation conversion transmission mechanisms, for example. A mechanical reduction transmission mechanism can be arranged between the electric motor and the threaded transmission mechanism. The electric motor and the threaded transmission mechanism form an electromechanical external force drive device for the external force piston and form an electromechanical external force brake pressure generator together with the external force piston and the external force cylinder hole, wherein the present invention does not exclude other external force brake pressure generators besides the electromechanical external force brake pressure generator.

[0008] A master brake cylinder bore in the hydraulic block is not mandatory for the invention, although it is preferred that a master brake cylinder bore is provided in the hydraulic block. The master brake cylinder bore is provided for one or more pistons of a master brake cylinder for muscle-operated or power-assisted actuation of a vehicle brake system, i.e. one of the pistons can be moved mechanically in the master brake cylinder bore by means of a (foot) brake pedal or a (hand) brake lever.

[0009] If the hydraulic block has a master brake cylinder bore, the hydraulic block preferably also has a simulator cylinder bore for a pedal travel simulator, in which a simulator piston loaded with, for example, a spring or gas pressure is accommodated axially displaceably. The pedal travel simulator is preferably connected to the master brake cylinder via a solenoid valve (which may also be referred to as a simulator valve) and is used to receive brake fluid from the master brake cylinder bore when the master brake cylinder is hydraulically separated from the vehicle brake system by closing the separation valve when an external force operates the vehicle brake system, so that the brake fluid cannot be squeezed out of the master brake cylinder into the vehicle brake system. The pedal travel simulator enables the master brake cylinder piston to move when an external force operates the vehicle brake system.

[0010] The through-holes or blind holes referred to here as “drilled holes” or “cylinder holes” can also be produced other than by drilling.

[0011] Further developments and advantageous embodiments according to the invention are also provided herein.

[0012] All features disclosed in the description and the drawings can be implemented in embodiments of the invention individually or in principle in any combination. Embodiments of the invention which do not have all features of embodiments of the invention but only have one or more features are in principle possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The invention is explained in more detail below with reference to the embodiments shown in the drawings. The single FIGURE shows a section through the hydraulic block axially through the external force cylinder bore of the hydraulic unit according to the invention. DETAILED DESCRIPTION

[0014] exist Figure 1 The hydraulic unit 1 according to the invention shown in FIG. 1 is provided for generating pressure in a hydraulic externally-powered vehicle brake system with slip control. Such slip control systems are, for example, anti-lock braking, drive slip control and / or driving dynamics control / electronic stability programs, for which the abbreviations ABS, ASR, FDR / ESP are often used.

[0015] The hydraulic assembly 1 according to the invention has a hydraulic block 2, which is used to mechanically fix and hydraulically connect hydraulic and other components of the slip control, such as solenoid valves, non-return valves, hydraulic reservoirs and damper chambers. The components are arranged on and in the hydraulic block 1 and are hydraulically connected to one another via bores (not shown) of the hydraulic block 2 according to the hydraulic circuit diagram of the external vehicle brake system and the slip control. Two solenoid valves 27 are shown as switching symbols by way of example.

[0016] In the embodiment of the invention shown and described, the hydraulic block 2 is a cuboid flat metal block, for example made of an aluminum alloy, which is provided with holes for receiving components and is drilled according to the hydraulic circuit diagram of the vehicle brake system and the slip control.

[0017] The hydraulic block 2 has two large through holes on opposite sides perpendicular to the hydraulic block 2 as external force cylinder holes 3, in which an external force piston 4 is axially movably accommodated. In order to guide the external force piston 4 axially movably, a guide bushing 5 is axially fixedly arranged in the external force cylinder hole 3, and the guide bushing radially guides the external force piston 4 in the external force cylinder hole 3.

[0018] In this embodiment, the guide bushing 5 is made of plastic. Externally, the guide bushing 5 is sealed in the external force cylinder bore 3 in the hydraulic block 2 by a press fit.

[0019] Internally, the guide bushing 5 has a circumferential sealing groove 6 in which a sealing ring is arranged as a first piston seal 7. The first piston seal 7, which can also be understood as a high-pressure seal for the external force piston 4, seals between the external force piston 4 and the guide bushing 5.

[0020] The annular step 8 of the external force cylinder bore 3 is axially connected to the guide bushing 5, with which the external force cylinder bore 3 is reduced to a smaller diameter than in the area of ​​the guide bushing 5. The annular step 8 has an axial spacing from the guide bushing 5, thereby forming a surrounding groove, in which a second piston seal 9 is arranged, which can also be understood as a low-pressure seal. The second piston seal 9 is axially held between the guide bushing 5 and the annular step 8 of the external force cylinder bore 3. It seals between the external force cylinder bore 3 and the external force piston 4.

[0021] Axially at the height of the guide bushing 5, the second brake fluid line 10 opens into the external force cylinder bore 3 in the hydraulic block 2. In this embodiment, the second brake fluid line 10 opens into the external force cylinder bore 3 between the first and second piston seals 7, 9. The guide bushing 5 has a channel 11, which leads from the opening of the second brake fluid line 10 to the end side of the guide bushing 5 facing the annular step 8, so that the second brake fluid line 10 is connected to the second piston seal 9 on the end side facing the guide bushing 5 through the channel 11. As shown in the figure, the channel 11 can be, for example, an axis-parallel groove in the outer circumference of the guide bushing 5 or a bore (not shown) in the guide bushing 5 extending from the outer circumference to the end face of the guide bushing 5 facing the annular step 8. The guide bushing 5 is arranged in a rotational manner in the external force cylinder bore 3 so that its channel 11 is connected to the second brake fluid line 10. The second brake fluid line 10 is connected to a brake fluid container (not shown) and causes lubrication of the outer circumference of the external force piston 4 in the region of the second piston seal 9. During the axial movement, the brake fluid on the outer circumference of the external force piston 4 also reaches the first piston seal 7 , so that both piston seals 7 , 9 are lubricated.

[0022] On the outside, the guide bushing 5 has a circumferential groove 12, which is interrupted at the channel 11 and ends at a distance from the channel 11 on both sides, so that the groove 12 is not connected to the channel 11. The first brake fluid line 13 opens into the external force cylinder bore 3 axially at the height of the groove 12 in the outer circumference of the guide bushing 5 at two circumferential locations, and the brake fluid lines are connected to each other through the groove 12. In this way, the two first brake fluid lines 13 that connect the hydraulic components of the slip control part of the hydraulic external force vehicle brake device to each other are connected to each other on the outside around the external force cylinder bore 3. The two first brake fluid lines 13 are located outside the cross-sectional plane in the illustrated embodiment of the present invention, so that one of the two first brake fluid lines 13 is shown as rotated into the cross-sectional plane. The other first brake fluid line 13 is not visible in the drawing.

[0023] The external force cylinder bore 3 passing through the hydraulic block 2 is closed at one end by a cup-shaped cylinder cover 14, which in this embodiment is screwed into the external force cylinder bore 3. For example, the fixing can also be carried out by means of a spring ring, which engages externally in a circumferential groove inside the external force cylinder bore 3 and internally in a circumferential groove outside the cylinder cover 14 (not shown). The cylinder cover 14 protrudes outward from the hydraulic block 2 and extends the external force cylinder bore 3 and thus the displacement stroke of the external force piston 4.

[0024] The cylinder cover 14 is a crown with radial slots, which has an edge, with which the guide bushing 5 is axially held in the outer cylinder bore 3. The brake fluid can pass through the radial slots.

[0025] Outside the guide bushing 5, the external force cylinder bore 3 has a larger diameter than the external force piston 4, so that an annular gap 15 exists between the external force piston 4 and the external force cylinder bore 3. Likewise, the cylinder head 14 has a larger inner diameter than the external force piston 4, so that an annular gap 16 also exists in the cylinder head 14 between the external force piston and the cylinder head 14. As a result, the external force piston 4 is radially guided only in the guide bushing 5.

[0026] In order to move the external force piston 4 in the external force cylinder bore 3 to generate a brake pressure using external force, the hydraulic assembly 1 has an electric motor 17, which moves the external force piston 4 in the external force cylinder bore 3 through a planetary gear transmission mechanism 18 and a ball screw transmission mechanism 19 as a reduction transmission mechanism. The ball screw transmission mechanism 19 can also be generally understood as a screw transmission mechanism or as a rotation / translation conversion transmission mechanism. The ball screw transmission mechanism 19 is partially arranged in the external force piston 4 coaxially with the external force piston 4 and the external force cylinder bore 3, and the external force piston is implemented as a hollow piston for this purpose. The ball screw transmission mechanism 19 is supported by a ball bearing 20, which is arranged on the outside of the hydraulic block 2 using a tubular bearing holder 21. The planetary gear transmission mechanism 18 is also arranged coaxially with the external force cylinder bore 3 and the external force piston 4 between the ball screw transmission mechanism 19 and the electric motor 17. The electric motor 17 has a motor housing 22, which is also screwed to the hydraulic block 2 externally coaxially with the external force cylinder bore 3 and the external force piston 4. The electric motor 17, the planetary gear mechanism 18 and the ball screw mechanism 19 form an electromechanical external force drive device 23, by means of which the external force piston 4 can be axially moved in the external force cylinder bore 3 by means of external force to generate a brake pressure for the vehicle brake system. Together with the external force cylinder bore 3, the cylinder head 14 and the external force piston 4, the external force drive device 23 forms an external force brake pressure generator 24 of the hydraulic assembly 1 according to the invention. The invention does not exclude a different way of generating brake pressure by means of external force than by electromechanical means.

[0027] In the embodiment of the invention shown and described, the hydraulic block 2 has a master brake cylinder bore 25, in which a master brake cylinder piston (not shown) can be arranged, which is mechanically displaced in the master brake cylinder bore 25 via a piston rod with a foot brake pedal or a hand brake lever (not shown). In addition, the hydraulic block 2 has a simulator cylinder bore 26 for a simulator piston (not shown), which is, for example, spring-loaded. Brake fluid can be squeezed out of the master brake cylinder bore 25 into the simulator cylinder bore 26, so that the master brake cylinder piston can be displaced in the master brake cylinder bore 25 when the vehicle brake system is actuated by external force. In addition to using the external force brake pressure generator 24, the vehicle brake system can also be actuated by muscle force by displacing the master brake cylinder piston in the master brake cylinder bore 25, which is provided in particular when the external force brake pressure generator 24 fails or fails.

[0028] The external force cylinder bore 3 , the master brake cylinder bore 25 and / or the simulator cylinder bore 26 can also be produced in a manner other than by drilling.

Claims

1. A hydraulic block for a hydraulic assembly of a hydraulic vehicle brake system, the hydraulic block having an external force cylinder hole (3) in which an external force piston (4) can be axially moved, characterized in that: A guide bushing (5) is arranged in the external force cylinder bore (3), and the guide bushing radially guides the external force piston (4) in the external force cylinder bore (3), wherein the external force cylinder bore (3) has an annular step (8) on the end side of the guide bushing (5), and the external force cylinder bore (3) is reduced to a smaller diameter than in the area of ​​the guide bushing (5), and a second piston seal (9) is arranged on the radial inner side of the annular step (8), and the second piston seal (9) is axially retained in the annular step (8) by the guide bushing (5).

2. A hydraulic block for a hydraulic assembly of a hydraulic vehicle brake system, the hydraulic block having an external force cylinder hole (3) in which an external force piston (4) can be axially moved, characterized in that: A guide bushing (5) is arranged in the external force cylinder bore (3), which radially guides the external force piston (4) in the external force cylinder bore (3), wherein the guide bushing (5) has a circumferential groove (12) on the outside, and wherein a first brake fluid line (13) opens into the external force cylinder bore (3) axially at the height of the circumferential groove (12) on the outside of the guide bushing (5) at two circumferential locations, and the first brake fluid lines (13) are connected to each other through the circumferential groove (12) on the outside of the guide bushing (5).

3. A hydraulic block for a hydraulic assembly of a hydraulic vehicle brake system, the hydraulic block having an external force cylinder hole (3) in which an external force piston (4) can be axially moved, characterized in that: A guide bushing (5) is arranged in the external force cylinder hole (3), and the guide bushing radially guides the external force piston (4) in the external force cylinder hole (3), wherein the external force cylinder hole (3) passes through the hydraulic block (2), and the end of the external force cylinder hole (3) is closed by a cylinder cover (14), and the cylinder cover extends from the hydraulic block (2) and axially extends the movement stroke of the external force cylinder hole (3) and the external force piston (4).

4. The hydraulic block according to any one of claims 1 to 3, characterized in that The guide bushing (5) has a circumferential sealing groove (6) in its inner circumferential surface, in which a first piston seal (7) is arranged, which seals between the external force piston (4) and the guide bushing (5).

5. The hydraulic block according to claim 2 or 3, characterized in that: The external force cylinder hole (3) has an annular step (8) on the end side of the guide bushing (5), in which a second piston seal (9) is arranged and axially retained in the annular step (8) by the guide bushing (5).

6. The hydraulic block according to claim 5, characterized in that: The second brake fluid line (10) axially opens into the external force cylinder hole (3) at the height of the guide bushing (5), and the guide bushing (5) has a channel (11) which leads from the second brake fluid line (10) to an annular step (8) on the end side of the guide bushing (5) of the external force cylinder hole (3).

7. The hydraulic block according to claim 1 or 3, characterized in that: The guide bushing (5) has an external circumferential groove (12), and axially at the height of the external circumferential groove (12) of the guide bushing (5), at two circumferential positions, a first brake fluid line (13) opens into the external force cylinder hole (3), and the first brake fluid lines (13) are connected to each other through the external circumferential groove (12) of the guide bushing (5).

8. The hydraulic block according to claim 1 or 2, characterized in that: The external force cylinder hole (3) passes through the hydraulic block (2), and the end of the external force cylinder hole (3) is closed by a cylinder cover (14), which extends from the hydraulic block (2) and axially extends the external force cylinder hole (3).

9. The hydraulic block according to claim 3, characterized in that: Outside the guide bushing (5), there is an annular gap (15) between the external force piston (4) and the external force cylinder bore and / or there is an annular gap (16) between the external force piston (4) and the cylinder head (14).

10. The hydraulic block according to any one of claims 1 to 3, characterized in that An external force driving device (24) for the external force piston (4) is arranged on the hydraulic block (2) at the opening of the external force cylinder hole (3), and the external force driving device can be used to move the external force piston (4) in the external force cylinder hole (3) to generate braking pressure.

11. The hydraulic block according to any one of claims 1 to 3, characterized in that The hydraulic block (2) has a master brake cylinder hole (25) and / or a simulator cylinder hole (26).

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