Brake control device, brake system, and method for operating the brake system

Abstract

The present invention relates to an electrohydraulic brake control device (100, 100') for hydraulically actuable wheel brakes (8a, 8b), the brake control device comprising an electrically controllable hydraulic source (5), inlet valves (6a, 6b) for each of the hydraulically actuable wheel brakes (8a, 8b), outlet valves (7a, 7b) for each of the hydraulically actuable wheel brakes (8a, 8b), and a pressure medium reservoir (4), the brake control device (100, 100') comprising a pressure increase wheel connection (61a, 61b) and a pressure decrease wheel connection (62a, 62b) for at least one of the hydraulically actuable wheel brakes (8a, 8b). The present invention also relates to a brake system for a motor vehicle, the brake system comprising at least two hydraulically actuable wheel brakes (8a, 8b), an electrically controllable hydraulic source (5), inlet valves (6a, 6b) for each of the hydraulically actuable wheel brakes (8a, 8b), outlet valves (7a, 7b) for each of the hydraulically actuable wheel brakes (8a, 8b), and an electrohydraulic brake control device (100, 100') comprising a pressure medium reservoir, the brake control device (100, 100') for each of the hydraulically actuable wheel brakes (8a, 8b) being connected to the hydraulically actuable wheel brakes (8a, 8b) via first and second hydraulic connection elements (81a, 82a, 81b, 82b). The present invention further relates to a method for operating a brake system of this type.

Description

Technical Field

[0001] The present invention relates to a brake control device according to the preamble of claim 1, a brake system for a motor vehicle according to the preamble of claim 8, and a method for operating a brake system.

Background Art

[0002] German Patent Application Publication No. 102015001541A1 discloses a hydraulically actuated wheel brake having a brake disc, a brake caliper, and brake pads, the brake pads being able to be filled with brake fluid and increasing in size during the braking phase. In the process, a chamber having a brake pad pressed against the brake disc and an inlet formed on the brake pad for introducing brake fluid into the chamber is provided, and the brake pad has a return port different from the inlet for removing brake fluid from the chamber. The brake system is designed so that the brake fluid can be circulated through the chamber via the inlet and the return port by a transport unit to cool the brake pad.

[0003] An electrohydraulic brake control device and a by-wire brake system having four hydraulically actuable wheel brakes are known from International Publication No. 2018 / 130393A1 pamphlet. The brake control device includes a master brake cylinder, an electrically controllable pressure source, and exactly four hydraulic wheel connections for four hydraulically actuable wheel brakes. Each of the four hydraulically actuable wheel brakes has a single connection connected to exactly one of the four hydraulic wheel connections of the electrohydraulic brake control device.

[0004] A so-called hybrid by-wire brake system is known in German Patent Application Publication No. 102012217825A1, which comprises an electro-hydraulic brake control device having a master brake cylinder and an electrically controllable pressure source, two hydraulically actuated wheel brakes, and two wheel brakes, each actuated by an electromechanical actuator. Each of the two hydraulically actuated wheel brakes has a single connection that is precisely connected to one of the two hydraulic wheel connections of the electro-hydraulic brake control device.

[0005] Such drive-by-wire brake systems must be filled with brake fluid (pressure medium) using a filling device at the automobile manufacturer's factory, and emptied properly as needed. [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide an electrohydraulic brake control device and a by-wire brake system for a by-wire brake system that enables self-filling, i.e., filling of the pressure medium without additional filling equipment, thereby avoiding a time-wasting, error-prone process in the manufacturing plant of an automobile manufacturer.

[0007] This objective is achieved by the electrohydraulic brake control device described in claim 1 and the brake system described in claim 8.

[0008] A further object of the present invention is to provide a method for activating a brake system, which generates, restores, or improves the function of the brake system.

[0009] This objective is achieved by the method described in claim 14. [Means for solving the problem]

[0010] The concept of the present invention relating to an electrohydraulic brake control device is based on the fact that an electrohydraulic brake control device for a hydraulically actuated wheel brake comprises an electrically activatable hydraulic source, an inlet valve for each of the hydraulically actuated wheel brakes, an outlet valve for each of the hydraulically actuated wheel brakes, and a pressure medium reservoir. For at least one of the hydraulically actuated wheel brakes, the brake control device has a pressure-increasing wheel connection and a pressure-relieving wheel connection. This means that the brake control device has two separate wheel connections, namely a pressure-increasing wheel connection and a pressure-relieving wheel connection, for at least one hydraulically actuated wheel brake.

[0011] The brake control device, which is automatically electrically controlled by suitable activation of an electrically activatable pressure source and inlet and outlet valves for at least one hydraulically actuated wheel brake, offers the advantage that it can transport pressure medium from the electrically activatable pressure source to the pressure medium reservoir via the wheel brake inlet valve, pressure rise wheel connection, wheel brake, and pressure release wheel connection. This allows the brake system itself to self-fill or purge the wheel brake when the brake system is installed in the vehicle.

[0012] Preferably, for at least one hydraulically actuated wheel brake, a pressure-increasing wheel connection is connected to an electrically activated hydraulic source via an inlet valve assigned to the hydraulically actuated wheel brake, and a pressure-relieving wheel connection is connected to a pressure medium reservoir via an outlet valve assigned to the hydraulically actuated wheel brake.

[0013] The brake control device is designed for hydraulically actuated wheel brakes, that is, for at least two hydraulically actuated wheel brakes. Accordingly, the brake control device comprises at least two inlet valves and at least two outlet valves.

[0014] The brake control device is preferably designed for two hydraulically actuated wheel brakes. In this case, the brake control device comprises two inlet valves and two outlet valves for the two hydraulically actuated wheel brakes. Particularly preferably, the brake control device comprises (specifically) two pressure-boosting wheel connections and two pressure-relieving wheel connections, wherein the first pressure-boosting wheel connection is connected via a first inlet valve to an electrically activated hydraulic source, and the first pressure-relieving wheel connection is connected via a first outlet valve to a pressure medium reservoir, and the second pressure-boosting wheel connection is connected via a second inlet valve to an electrically activated hydraulic source, and the second pressure-relieving wheel connection is connected via a second outlet valve to a pressure medium reservoir. Particularly preferably, a first inlet valve is connected to the pressure port of a first hydraulically actuated wheel brake via a first pressure-boosting wheel connection and a first hydraulic connection element; a first outlet valve is connected to the drain port of a first hydraulically actuated wheel brake via a first pressure-relieving wheel connection and a second hydraulic connection element; a second inlet valve is connected to the pressure port of a second hydraulically actuated wheel brake via a second pressure-boosting wheel connection and a further first hydraulic connection element; and a second outlet valve is connected to the drain port of a second hydraulically actuated wheel brake via a second pressure-relieving wheel connection and a further second hydraulic connection element.

[0015] The pressure medium reservoir is preferably a pressure medium reservoir under atmospheric pressure.

[0016] According to a preferred embodiment, the brake control device for each of the hydraulically actuated wheel brakes has in each case a pressure rise wheel connection and a pressure release wheel connection, and for each of the hydraulically actuated wheel brakes, the pressure rise wheel connection is connected to an electrically activated hydraulic source via an inlet valve assigned to the (each) hydraulically actuated wheel brake, and the pressure release wheel connection is connected to a pressure medium reservoir via an outlet valve assigned to the (each) hydraulically actuated wheel brake. This means that the electrohydraulic brake control device has two (separate) wheel connections for each of the hydraulically actuated wheel brakes: a pressure rise wheel connection for supplying pressure medium from an electrically activated pressure source to the corresponding wheel brake via a brake control device inlet valve assigned to the corresponding wheel brake, and a pressure release wheel connection for releasing pressure medium from the corresponding wheel brake to a pressure medium reservoir via a brake control device outlet valve assigned to the corresponding wheel brake. This brake control device offers the advantage that the electrically controlled brake control device, which is automatically controlled by inlet and outlet valves for each of the electrically activated pressure sources and hydraulically operated wheel brakes, can transport pressure medium from the electrically activated pressure source to the pressure medium reservoir via the corresponding wheel brake inlet valve, associated pressure rise wheel connection, corresponding wheel brake, and associated pressure release wheel connection. This allows the brake system itself to self-fill or purge all or the entire wheel brake when the brake system is installed in the vehicle.

[0017] Therefore, when an electrohydraulic brake control device is designed for two hydraulically actuated wheel brakes, the brake control device preferably has two pressure-boosting wheel connections and two pressure-releasing wheel connections, thus a total of four separate wheel connections for connecting two hydraulically actuated wheel brakes. The two pressure-boosting wheel connections are provided, in particular, to increase the pressure of each wheel brake by an electrically activated pressure source via an inlet valve assigned to each wheel brake, and the two pressure-releasing wheel connections are provided, in particular, to release the pressure of each wheel brake to a pressure medium reservoir via an outlet valve assigned to each wheel brake.

[0018] Therefore, when an electrohydraulic brake control device is designed for four hydraulically actuated wheel brakes, the brake control device preferably has four pressure-increasing wheel connections and four pressure-relieving wheel connections, i.e., a total of eight separate wheel connections.

[0019] Preferably, for at least one of the hydraulically actuated wheel brakes, and particularly preferably for each of the hydraulically actuated wheel brakes, no hydraulic connection line is provided in the brake control device between the wheel brake side connection of the inlet valve of the corresponding hydraulically actuated wheel brake and the wheel brake side connection of the outlet valve of the corresponding hydraulically actuated wheel brake.

[0020] Preferably, in addition to an electrically activatable hydraulic source, the electro-hydraulic brake control device does not include any other hydraulic sources. Particularly preferably, the brake control device does not include a master brake cylinder actuated by a brake pedal to actuate the wheel brakes at a hydraulic fallback level. The brake control device also particularly preferably does not include a second electrically activatable hydraulic source.

[0021] Preferably, the electrically activatable hydraulic source is formed by a cylinder-piston device having a pressure chamber and a piston, the piston being able to be pushed back and forth by an electromechanical actuator. This means that it is possible to both push the pressure medium into the wheel brake and draw it up from the wheel brake. The piston moves forward (in the direction of brake operation) to increase the brake pressure and backward (i.e., in the opposite direction of brake operation) to release the brake pressure. The piston also moves backward (i.e., in the opposite direction of brake operation) to replenish the pressure medium from the pressure medium reservoir to the pressure source.

[0022] Preferably, an electrically activated hydraulic pressure source, particularly its pressure chamber, is connected via an electrically actuated activation valve to the brake line section to which the inlet valve of the brake control device is connected. Particularly preferably, the activation valve is configured to be normally closed. The activation valve allows the pressure source for replenishing the pressure medium from the pressure medium reservoir to be hydraulically separated from the inlet valve.

[0023] Preferably, the brake line section can be connected to a pressure medium reservoir via an electrically actuated isolation valve. This allows the inlet valve to be hydraulically connected to the pressure medium reservoir, thereby reducing the pressure on the wheel brake. Particularly preferably, the isolation valve is configured to be normally open, and therefore, in a shut-off state where the brake control device or brake system is not operating, the wheel brake is hydraulically connected to the pressure medium reservoir.

[0024] According to a preferred embodiment, the brake line section is hydraulically connected directly to a pressure medium reservoir via a separation valve and a compensation line section.

[0025] According to another preferred embodiment, the brake line section is connected to the pressure chamber of the master brake cylinder via a separating valve and a line section. The pressure chamber of the master brake cylinder is connected to the pressure medium reservoir, particularly preferably via one or more breather holes when the master brake cylinder piston is not actuated. This hydraulic connection between the pressure chamber and the pressure medium reservoir is separated when the master brake cylinder piston (fully) actuates in the actuating direction.

[0026] The pressure source is preferably formed by a cylinder-piston device having a hydraulic pressure chamber, a suction port, and a pressure port, the piston of which moves back and forth or can be pushed back and forth by an electromechanical actuator. The suction port is particularly preferably connected to the pressure medium reservoir via a replenishment line having a check valve that opens in the flow direction towards the pressure chamber. The pressure connection is preferably connected to the brake line section via an activation valve.

[0027] Preferably, the pressure medium reservoir has two reservoir chambers separated by a partition wall, and the outlet valve, and thus one or more pressure relief wheel connections, are connected to one reservoir chamber, and the replenishment line of the electrically activatable hydraulic pressure source is connected to the other reservoir chamber. This enables, in particular, the self-venting (or purging) of the brake control device during the replacement of the pressure medium (brake fluid replacement) at the workplace or, particularly preferably, while the vehicle is in operation. For example, if vapor bubbles occur in the brake system as a result of reheating while the vehicle is stationary, this can be detected by the increased volume uptake in the brake system test routine after the vehicle has been parked. As a result, a self-venting cycle is then initiated, the pressure medium reservoir acts as a gas bubble separator, and the separation into the two reservoir chambers prevents the foamed pressure medium (brake fluid) from being sucked up again.

[0028] The concept of the present invention regarding the braking system is based on the fact that the braking system comprises at least two hydraulically actuable wheel brakes and an electro-hydraulic brake control device. The electro-hydraulic brake control device comprises an electrically actuable hydraulic source, an inlet valve for each hydraulically actuable wheel brake, an outlet valve for each hydraulically actuable wheel brake, and a pressure medium reservoir. For each of the hydraulically actuable wheel brakes, the brake control device is connected to the hydraulically actuable wheel brake via first and second (i.e., separate) hydraulic connection elements. This means that the braking system has two separate hydraulic connection elements for each hydraulically actuable wheel brake, namely a first hydraulic connection element and a second hydraulic connection element, via which the brake control device is connected to the corresponding / respective hydraulically actuable wheel brake.

[0029] The braking system can lead the pressure medium from the brake control device to the hydraulically actuable wheel brake via the first hydraulic connection element for each wheel brake, and has the advantage that the pressure medium can be separately redirected from the wheel brake to the brake control device via the second hydraulic connection element. Thus, the self-filling or purging of the wheel brakes by the braking system is possible by activation of the electrically actuable pressure source, preferably and advantageously automatically.

[0030] Preferably, the brake control device for each of the hydraulically actuated wheel brakes has a pressure-increasing wheel connection and a pressure-relieving wheel connection. Particularly preferably, for each of the hydraulically actuated wheel brakes, the pressure-increasing wheel connection is connected to an electrically activated hydraulic source via an inlet valve assigned to each hydraulically actuated wheel brake, and the pressure-relieving wheel connection is connected to a pressure medium reservoir via an outlet valve assigned to each hydraulically actuated wheel brake. Thus, for each hydraulically actuated wheel brake, the pressure medium can be guided from the brake control device to the hydraulically actuated wheel brake via the pressure-increasing wheel connection and the first hydraulic connection element, flow through the wheel brake, and released to the brake control device via the second hydraulic connection element and the pressure-relieving wheel connection.

[0031] Preferably, for each hydraulically actuated wheel brake, the first hydraulic connection element connects an inlet valve assigned to the hydraulically actuated wheel brake to the pressure port of the hydraulically actuated wheel brake, particularly preferably via a brake control device pressure boosting wheel connection assigned to the inlet valve. This connection is particularly suitable for increasing the pressure in the hydraulically actuated wheel brake by a hydraulic source.

[0032] Preferably, for each hydraulically actuated wheel brake, a second hydraulic connection element connects an outlet valve assigned to the hydraulically actuated wheel brake to the drain port of the hydraulically actuated wheel brake, particularly preferably via a brake control device pressure release wheel connection assigned to the outlet valve. This connection is particularly suitable for releasing pressure from the hydraulically actuated wheel brake to the pressure medium reservoir of the brake control device.

[0033] Preferably, the brake control device is designed as an electro-hydraulic brake control device according to the present invention.

[0034] The pressure medium reservoir is preferably a pressure medium reservoir under atmospheric pressure.

[0035] According to a preferred development of the braking system, the braking system comprises at least one wheel brake that can be actuated by an electromechanical actuator. Particularly preferably, the braking system comprises two wheel brakes, each actuated by an electromechanical actuator. These two electromechanically actuated wheel brakes are very preferably assigned to a second vehicle axle of the vehicle. Advantageously, the second vehicle axle is the rear axle of the vehicle. Particularly preferably, the braking system comprises exactly two wheel brakes (i.e., two electromechanically actuated wheel brakes), each actuated by an electromechanical actuator.

[0036] The braking system preferably comprises, more precisely, two hydraulically actuated wheel brakes. Particularly preferably, these are assigned to the first vehicle axle of the vehicle. Very particularly preferably, the two hydraulically actuated wheel brakes are assigned to the front axle of the vehicle.

[0037] According to a preferred development of the brake system, the brake system comprises two hydraulically actuated wheel brakes, an electro-hydraulic brake control device, and two electromechanically actuated wheel brakes. The brake system particularly preferably comprises two hydraulically actuated wheel brakes.

[0038] Preferably, the brake system comprises two hydraulically actuated wheel brakes, an electro-hydraulic brake control device according to the present invention, and two electromechanically actuated wheel brakes. Particularly preferably, the brake system comprises two hydraulically actuated wheel brakes.

[0039] Preferably, the brake system is designed to determine an actuation signal that quantifies the desire to brake as a result of action by the vehicle driver, and includes an actuation device connected to an electro-hydraulic brake control device via a signal connection or data connection to transmit the actuation signal. Particularly preferably, the actuation device is in the form of an electric brake pedal (ePedal). Particularly preferably, there is no mechanical hydraulic connection from the actuation device to the brake control device or a hydraulically actuated wheel brake.

[0040] Preferably, the electro-hydraulic brake control device comprises a first electronic control and adjustment unit and a second electronic control and adjustment unit, wherein an electrically activatable hydraulic source is activated by the second electronic control and adjustment unit, and inlet and outlet valves are activated by the first electronic control and adjustment unit.

[0041] Preferably, an electrically activated hydraulic source is detachably hydraulically connected to the inlet valve via an electrically actuated activation valve, which is activated by a second electronic control and adjustment unit.

[0042] The separation valve between the brake line section and the pressure medium reservoir is preferably activated by a second electronic control and adjustment unit.

[0043] Preferably, the braking system comprises a first electrical compartment and a second electrical compartment, the second electrical compartment being independent of the first electrical compartment.

[0044] Preferably, the first electronic control and adjustment unit of the electrohydraulic brake control device or the first electrical compartment of the brake system is supplied by a first electrical energy source, and the second electronic control and adjustment unit of the electrohydraulic brake control device or the second electrical compartment of the brake system is supplied by a second electrical energy source independent of the first electrical energy source. Thus, the first energy source is part of the first electrical compartment, and the second energy source is part of the second electrical compartment.

[0045] Preferably, the brake system comprises two wheel brakes, each actuated by an electromechanical actuator, wherein one of the electromechanical actuator-actuated wheel brakes belongs to a first electrical compartment of the brake system, and the other electromechanical actuator-actuated wheel brake belongs to a second electrical compartment of the brake system.

[0046] Preferably, the brake system comprises two wheel brakes (i.e., two electromechanically actuated wheel brakes) each actuated by an electromechanical actuator, one of which is supplied with electrical energy from a first electrical energy source, and the other wheel brake, which is also actuated by an electromechanical actuator, is supplied with electrical energy from a second electrical energy source independent of the first electrical energy source. Particularly preferably, the brake control device is supplied with electrical energy from the first and second electrical energy sources. Very particularly preferably, the second electronic control and adjustment unit and electrically activated hydraulic source of the brake control device are supplied with electrical energy from the first electrical energy source, and the first electronic control and adjustment unit, as well as the inlet and outlet valves, are supplied with electrical energy from the second electrical energy source.

[0047] Preferably, the braking system comprises two electromechanically actuated wheel brakes, each of which is equipped with a separate electronic control and adjustment unit for activating the electromechanically actuated wheel brake's electromechanically actuated actuator.

[0048] Preferably, the brake system has a first data bus, in particular a first CAN bus, and a second data bus, in particular a second CAN bus, or is connected to the first data bus and the second data bus.

[0049] Preferably, the first data bus connects a first electronic control and adjustment unit of an electrohydraulic brake control device to two electronic control and adjustment units of an electromechanically operable wheel brake.

[0050] Preferably, the second data bus connects the first electronic control and adjustment unit of the electrohydraulic brake control device to two electronic control and adjustment units of the electromechanically operable wheel brake.

[0051] Preferably, the first and second data buses are connected to further electronic control and adjustment units, particularly to a central vehicle control / adjustment unit. Particularly preferably, the actuation device is simply electrically connected to the further electronic control and adjustment unit.

[0052] Preferably, each of the two electronic control and adjustment units for activating one of the electromechanical actuators of an electromechanically actuated wheel brake is connected to a first data bus and a second data bus. This provides the advantage of redundant supply of the driver's braking desire to the two electromechanically actuated wheel brakes.

[0053] Preferably, the first data bus connects a second electronic control and adjustment unit of an electrohydraulic brake control device to two electronic control and adjustment units of an electromechanically operable wheel brake.

[0054] Preferably, each hydraulically actuated wheel brake of the brake system includes a pressure medium chamber for acting the brake elements, and the pressure medium chamber is connected to the pressure connection of the wheel brake to supply pressure medium from a brake control device or to connect to one of the inlet valves of the brake control device. In either case, the pressure medium chamber of the wheel brake is further connected to a drain port of the wheel brake to release pressure medium to a pressure medium reservoir of the brake control device or to connect to one of the outlet valves of the brake control device.

[0055] Preferably, the hydraulically operated wheel brake does not have any other vent connections, such as a drain screw or vent valve.

[0056] Preferably, when one of the hydraulically operated wheel brakes is installed in the vehicle, the drain port is located above the pressure port. Preferably, when a hydraulically operated wheel brake is installed in the brake system, the drain port for each wheel brake is located above the pressure port.

[0057] The concept of the present invention regarding a method for activating a brake system according to the present invention is based on the fact that a brake control device is used to perform a purge cycle, a) In particular, by activating an electrically activated hydraulic source in the operating direction of the brake, the pressure medium moves through the first inlet valve of the inlet valve, through the first hydraulically actuated wheel brake assigned to the first inlet valve, and through the outlet valve assigned to the first hydraulically actuated wheel brake, to or towards the pressure medium reservoir, and in particular thereafter, b) In particular, by activating an electrically activated hydraulic source in the opposite direction to the brake's operating direction, the pressure medium is drawn from the pressure medium reservoir into the electrically activated hydraulic source. In particular, steps a) and b) are repeated periodically.

[0058] Preferably, the brake system pressure medium reservoir has a first reservoir chamber and a second reservoir chamber, the reservoir chambers separated from each other by a partition wall, an outlet valve connected to the second reservoir chamber, and a replenishment line for an electrically activatable hydraulic source connected to the first reservoir chamber. In step a), the pressure medium is delivered to the second reservoir chamber, and in step b), the pressure medium is drawn up from the first reservoir chamber to the pressure source. For example, brake fluid replacement (pressure medium replacement) can be easily performed in the workshop by removing the old pressure medium from the second reservoir chamber of the pressure medium reservoir and filling the first reservoir chamber of the pressure medium reservoir with new pressure medium.

[0059] The method is preferably performed first for one of the hydraulically actuated wheel brakes, and then for the other hydraulically actuated wheel brake. Particularly preferably, the leak test of the brake system is then performed by a brake control device, in which the test pressure is increased and maintained by an electrically activated hydraulic source.

[0060] Preferably, in step a), in particular, before the electrically activated hydraulic source in the braking direction is activated, the activation valve of the electro-hydraulic brake control device is opened, the isolation valve of the electro-hydraulic brake control device is closed, and the outlet valve assigned to the first hydraulically activatable wheel brake is opened.

[0061] Preferably, when the piston of an electrically activatable hydraulic source reaches a predetermined endpoint in the operating direction of the brake, step a) ends, and the activation valve of the electro-hydraulic brake control device is closed before step b) begins.

[0062] Preferably, the method according to the present invention is performed after the brake system has been installed. Particularly preferably, the method for filling a hydraulically operated wheel brake with a pressure medium is performed after the brake system has been installed. Particularly preferably, the method is performed in an automobile manufacturing plant.

[0063] Preferably, a method according to the present invention for cooling a pressure medium is performed. Preferably, the method according to the present invention is performed when a thermal load of one of the brake system or wheel brakes is detected based on a monitoring method. Particularly preferably, the monitoring method is performed based on a brake temperature model and / or based on sensor data, in particular based on force sensor data by temperature output.

[0064] Preferably, the method according to the present invention for venting a brake control device is performed. Preferably, the method according to the present invention is repeated and / or performed under predetermined conditions. Particularly preferably, the method is repeated according to a predetermined time schedule.

[0065] Further preferred embodiments of the present invention can be obtained from the following description relating to dependent claims and figures. [Brief explanation of the drawing]

[0066] [Figure 1] A first exemplary embodiment of the brake control device according to the present invention is shown. [Figure 2] Figure 1 shows an exemplary embodiment of the brake system according to the present invention, which has a brake control device. [Figure 3] A second exemplary embodiment of the brake control device according to the present invention is shown. [Figure 4] Figure 3 shows an exemplary embodiment of the brake system according to the present invention, which has a brake control device. [Modes for carrying out the invention]

[0067] Figure 1 schematically shows a first exemplary embodiment of the brake control device 100 according to the present invention. The exemplary electrohydraulic brake control device 100 is designed to actuate two hydraulically actuated wheel brakes 8a, 8b. The brake control device 100 comprises an electrically activatable hydraulic source 5, a pressure medium reservoir 4 under atmospheric pressure, and electrically actuatable inlet valves 6a, 6b and electrically actuatable outlet valves 7a, 7b for the respective wheel brakes 8a, 8b.

[0068] Advantageously, the inlet valves 6a and 6b are normally open, while the outlet valves 7a and 7b are normally closed.

[0069] As an example, the brake control device 100 comprises a first electronic control and adjustment unit 11 (ECU1) and a second electronic control and adjustment unit 12 (ECU2). Alternatively, the brake control device 100 may also comprise an electronic control and adjustment unit ECU comprising two separate regions, for example, a first printed circuit board (corresponding to 11) and a second printed circuit board (corresponding to 12). In that case, the following applies accordingly to the first and second regions (first and second printed circuit boards) instead of the first and second electronic control and adjustment units 11 and 12.

[0070] The brake control device 100 is designed, for example, as an electro-hydraulic unit (HECU) having a hydraulic control and adjustment unit 60 (HCU, also called a valve block) and two electronic control and adjustment units 11, 12 (ECU1, ECU2).

[0071] The electrically activatable hydraulic source 5 is designed as a hydraulic cylinder piston device (i.e., a single-circuit electrohydraulic actuator (linear actuator)) having a pressure chamber 37 and a piston 36, the piston 36 of which can be pushed back and forth by a similarly schematic electric motor 35, to which a schematicly schematic rotational translation mechanism 39 is interconnected. A rotor position sensor, merely schematicly shown, which is responsible for detecting the rotor position of the electric motor 35, is indicated by reference numeral 44.

[0072] The pressure chamber 37 of the pressure source 5 is connected to the brake line section 13, to which inlet valves 6a and 6b are connected, via an electrically actuated activation valve 26. The activation valve 26 is advantageously normally closed. For this purpose, the pressure chamber 37 is connected to the activation valve 26 via a system pressure line 38, and the activation valve 26 is connected to the brake line section 13 at its outlet.

[0073] A pressure sensor 19, which determines the system pressure generated by the pressure source 5, is located in the brake line section 13.

[0074] To replenish the pressure medium in the pressure source 5, the pressure chamber 37 is connected to the pressure medium reservoir 4, preferably the first chamber / LAC chamber 4a of the pressure medium reservoir, via a replenishment line 42 to a check valve (replenishment valve) 53 that is open in the flow direction toward the pressure chamber 37. Thus, by closing the activation valve 26 and moving the piston 36 backward, the pressure medium can flow out from the pressure medium reservoir 4, or preferably from the first chamber 4a of the pressure medium reservoir, via the replenishment line 42 to the pressure chamber 37.

[0075] The exemplary brake control device 100 does not have any additional pressure sources other than the pressure source 5; that is, it does not have any additional electrically operable pressure sources or a master brake cylinder that can be operated by the brake pedal.

[0076] For each of the hydraulically actuated wheel brakes 8a and 8b, the brake control device comprises pressure-increasing wheel connections 61a and 61b and (separate) pressure-relieving wheel connections 62a and 62b. This means that the two separate wheel connections (61 and 62) are provided for the respective hydraulically actuated wheel brakes 8a and 8b, and the pressure-increasing wheel connections 61a and 61b and the pressure-relieving wheel connections 62a and 62b are not directly connected to each other in the brake control device 100. In particular, the wheel brake side connections of the respective inlet valves 6a and 6b are not connected to the wheel brake side connections of the corresponding outlet valves 7a and 7b via hydraulic connections (connection lines).

[0077] For each of the hydraulically actuated wheel brakes 8a, 8b, an electrically activated hydraulic source 5 is connected to the pressure rise wheel connections 61a, 61b via the corresponding inlet valves 6a, 6b assigned to the hydraulically actuated wheel brakes 8a, 8b. For each of the hydraulically actuated wheel brakes 8a, 8b, a pressure release wheel connection 62a, 62b is connected to the pressure medium reservoir 4 via the corresponding outlet valves 7a, 7b assigned to the hydraulically actuated wheel brakes 8a, 8b. As an example, the outlet valves 7a, 7b are connected to the pressure medium reservoir 4, preferably to the second chamber / return chamber 4b of the pressure medium reservoir, via a return line 14 (common in certain parts). Due to pressure release by the outlet valves 7a, 7b, a portion of the pressure medium released through the outlet valves 7a, 7b flows back into the pressure medium reservoir 4, or preferably into the second chamber of the pressure medium reservoir, via the return line 14.

[0078] Therefore, the brake control device 100 for each of the hydraulically actuated wheel brakes 8a and 8b is connected to the hydraulically actuated wheel brakes 8a and 8b via first hydraulic connection elements (first wheel lines) 81a and 81b and via second hydraulic connection elements (second wheel lines) 82a and 82b.

[0079] The first hydraulic connection element (first wheel line) 81a or 81b is connected, on the one hand, to the pressure-boosting wheel connection 61a or 61b of the brake control device assigned to the wheel brake 8a or 8b (and therefore the corresponding inlet valve 6a or 6b), and on the other hand, to the pressure connection 801a or 801b of the wheel brake 8a or 8b. The first wheel line 81a or 81b is used to increase the pressure of the wheel brake by the hydraulic source 5 (for increasing the wheel brake pressure).

[0080] The second hydraulic connection elements (second wheel lines) 82a, 82b are connected, on the one hand, to the pressure release wheel connection 62a or 62b of the brake control device 100, where the pressure release wheel connection is assigned to the wheel brake 8a or 8b (and therefore connected to the corresponding outlet valve 7a or 7b), and on the other hand, to the drain port (802a or 802b) of the wheel brake 8a or 8b. The release of pressure medium from the wheel brake 8a or 8b via the second wheel lines 82a or 82b is carried out through the outlet valve 7a or 7b to the pressure medium reservoir 4 of the brake control device 100 (to release wheel brake pressure).

[0081] The check valves 16a and 16b, which open in the direction of the brake circuit supply line 13, are connected in parallel to the inlet valves 6a and 6b, respectively.

[0082] To allow for depressurization of the wheel brakes 8a and 8b as needed, i.e., to allow the pressure of the wheel brakes 8a and 8b to be equal to that of the atmosphere, the brake line section 13 is connected to a pressure medium reservoir 4, preferably to a second chamber / return chamber 4b of the pressure medium reservoir, via an electrically actuated isolation valve 23 and a pressure equalization line section 41. The isolation valve 23 is advantageously normally open to ensure equal pressure of the wheel brakes with the atmosphere, for example, when the brake system is switched off and shut down.

[0083] Advantageously, the level measuring device 50 is positioned to determine the pressure medium level / state in the pressure medium reservoir 4. Preferably, the level measuring device 50 is positioned in the first chamber / LAC chamber 4a of the pressure medium reservoir.

[0084] For the electrical mounting, connection, and supply of individual electrically or electrically operable components of the brake control device 100 or brake system that can be activated or evaluated (see Figure 2), a first electrical compartment A and a second electrical compartment B are provided, which are electrically independent of each other.

[0085] In the diagram, the electrical components assigned to or belonging to the first electrical compartment A are indicated by arrows marked with A. The electrical components assigned to or belonging to the second electrical compartment B are indicated by arrows marked with B.

[0086] The first electronic control and adjustment unit 11 is assigned to or belongs to the first electrical compartment A, while the second electronic control and adjustment unit 12 is assigned to or belongs to the second electrical compartment B. Therefore, the electronic control and adjustment unit 11 and the second control and adjustment unit 12 are electrically independent.

[0087] To supply electrical energy to the brake control device 100 or the brake system, a first electrical energy source PWR2, for example, the vehicle's electrical system, and a second electrical energy source PWR1, for example, the second vehicle's electrical system, which is independent of the first energy source, are provided. The first electrical energy source PWR2 supplies energy to the first electrical compartment A, and the second electrical energy source PWR1 supplies energy to the second electrical compartment B.

[0088] The second electronic control and adjustment unit 12 activates the pressure source 5. Therefore, the first pressure source 5 is assigned to or associated with the second electrical compartment B. For example, the first pressure source 5 is supplied with energy (from the second electrical energy source PWR1) via the second electronic control and adjustment unit 12. For example, the first pressure source 5 can be activated or is activated exclusively by the second electronic control and adjustment unit 12.

[0089] To achieve redundancy in the starting of the pressure source 5, both compartments A and B of the brake control device 100 (or control and adjustment units 11, 12 and both printed circuit boards) are provided according to a preferred embodiment to be designed to start the motor-driven pressure source 5 based on operating information. For this purpose, for example, both compartments A and B (or both control and adjustment units 11, 12 or both printed circuit boards) are connected to the power electronics control device of the motor 35. Thus, even if one of compartments A or B fails, the targeted control of the hydraulic pressure of the brake control device 100 is still possible. The pressure source 5 can be started by the second electronic control and adjustment unit 12 and by the first electronic control and adjustment unit 11.

[0090] The remaining components of the brake system are, advantageously, assigned to either the first electronic control and adjustment unit 11 (compartment A) or the second electronic control and adjustment unit 12 (compartment B). That is, the components are activated or operated and / or supplied with electrical energy by the control and adjustment unit, and / or connected to the signal side of the control and adjustment unit, and / or evaluated by the control and adjustment unit. To avoid further redundancy, advantageously, the components are activated or operated, supplied with electrical energy, connected to the signal side, or evaluated by only one of the two electronic control and adjustment units 11, 12, or exclusively by one of the two electronic control and adjustment units 11, 12, and not by any other electronic control unit.

[0091] To enable the activation of the pressure source 5, the rotor position sensor 44 is assigned to the second electrical compartment B. The signal from the sensor is supplied to the second electronic control and adjustment unit 12, which evaluates and processes the signal.

[0092] The starting valve 26 and the separation valve 23 are also assigned to the second electrical compartment B and are activated by the second electronic control and adjustment unit 12.

[0093] Furthermore, the signal from the level measuring device 50 is supplied to the second electronic control and adjustment unit 12, which evaluates and processes it.

[0094] In contrast, the inlet valves 6a-6d and outlet valves 7a-7d are assigned to the first electrical compartment A and are activated by the first electronic control and adjustment unit 11.

[0095] The pressure sensor 19 is also assigned to the first electrical compartment A. The signal from the sensor is supplied to the first electronic control and adjustment unit 11, which evaluates and processes it.

[0096] Figure 2 schematically shows a first exemplary embodiment of the brake system according to the present invention. Figure 2 shows the system architecture of the brake system. The exemplary brake system comprises two hydraulically actuated wheel brakes 8a, 8b and two (also called electromechanically actuated wheel brakes 80a, 80b, abbreviated) wheel brakes 80a, 80b, each actuated by an electromechanical actuator, and an electro-hydraulic brake control device 100 as shown in Figure 1.

[0097] The hydraulically operated wheel brakes 8a and 8b are located on the front axles of the vehicle (FL: left front wheel, FR: right front wheel), while the electromechanically operated wheel brakes 80a and 80b (RL: left rear wheel, RR: right rear wheel) are located on the rear axles of the vehicle. Both the hydraulically operated and electromechanically operated wheel brakes 8a, 8b, 80a, and 80b are designed as the vehicle's service brakes.

[0098] The brake system is connected to a (brake) actuation device 300, which is designed to determine an actuation signal that quantifies the desire to brake as a result of action by the vehicle driver. The actuation device 300, which has a brake pedal 51, is in the form of an electric brake pedal (ePedal). This means that there is no mechanical-hydraulic connection from the actuation device 300 to the brake control device 100 or the hydraulically actuated wheel brakes 8a, 8b. Direct mechanical / hydraulic actuation of the wheel brakes 8a, 8b by the actuation device 300 is not possible. The actuation device 300 is connected to the brake control device 100 via a signal connection or data connection 150 to transmit actuation signals.

[0099] The pressure-increasing wheel connection 61a of the brake control device 100 is hydraulically connected to the pressure port 801a of the wheel brake 8a via the first wheel line 81a, and the pressure-relieving wheel connection 62a of the brake control device 100 is hydraulically connected to the drain port 802a of the wheel brake 8a via the second wheel line 82a. Accordingly, the pressure-increasing wheel connection 61b of the brake control device 100 is hydraulically connected to the pressure port 801b of the wheel brake 8b via the first wheel line 81b, and the pressure-relieving wheel connection 62b of the brake control device 100 is hydraulically connected to the drain port 802b of the wheel brake 8b via the second wheel line 82b.

[0100] Each of the electromechanically actuated wheel brakes 80a and 80b is equipped with separate electronically controlled and regulated units WCUa and WCUb (WCU: wheel control unit) for activating the corresponding electromechanical actuators of the wheel brakes 80a and 80b.

[0101] Wheel brake 80a is supplied with electrical energy from a second electrical energy source (PWR1) (section B), while wheel brake 80b is supplied with electrical energy from a first electrical energy source (PWR2) (section A).

[0102] Each wheel, FL, FR, RL, and RR, is assigned a wheel speed sensor WSS1, WSS2, WSS3, and WSS4 (WSS: wheel speed sensor). Signals from wheel speed sensors WSS3 and WSS4 of wheels with electromechanically actuated wheel brakes 80a and 80b are supplied to their respective electronic control and adjustment units WCU. Signals from wheel speed sensors WSS1 and WSS2 of wheels with hydraulically actuated wheel brakes 8a and 8b are supplied to the first electronic control and adjustment unit 11.

[0103] Furthermore, the brake system has a first data bus 57 ("onboard bus 1"), in particular a CAN bus, which connects the first electronic control and adjustment unit 11 to the electronic control and adjustment units WCUa and WCUb. The brake system further has a second data bus 58 ("brake bus 2"), in particular a CAN bus, which connects the first electronic control and adjustment unit 11 to the electronic control and adjustment units WCUa and WCUb.

[0104] Preferably, the electromechanically operable wheel brakes 80a, 80b are also designed to include a parking brake device.

[0105] Instead of two spatially separated electronic control and adjustment units 11 and 12, a (single) control and adjustment unit ECU may be provided, which comprises, for example, two electrically independent regions in the form of two printed circuit boards. In this case, one region, for example, the first printed circuit board, is assigned to section A, and the other region, for example, the second printed circuit board, is assigned to section B.

[0106] The electro-hydraulic front axle actuator (brake control device 100) consists of a hydraulic and electronic control unit (HCU and ECU). The hydraulic front wheel brakes 8a and 8b are each connected to the HCU by a dual pipeline (consisting of a first wheel line 81a, b and a second wheel line 82a, b). In both cases, one line is used to increase the pressure (first wheel lines 81a, b) and the other line is used to release the pressure (second wheel line 82a, b).

[0107] The ECU has two compartments, which are referred to here as compartment A and compartment B. These compartments A and B are independent areas, each having its own microcontroller, which runs a customized software program. Compartments A and B are connected to each other via an internal ECU data bus. Both compartments A and B can preferably access or activate actuators required for pressure setting by the pressure source 5.

[0108] Section A is simply electrically connected (connection 150) to a redundant actuator device 300 (ePedal), which converts the detected driver's brake request into a corresponding BUS signal to activate the electromechanical rear brakes 80a, 80b. For redundancy, the actuator device 300 (ePedal) is also simply electrically connected (connection 160) to an external electronic control and adjustment unit (ECU) 400 (of the brake system), which similarly converts the driver's request into a corresponding BUS signal. Thus, the transmission of the driver's request to the rear brakes 80a, 80b (by the first data bus 57 ("onboard bus 1") or the second data bus 58 ("brake bus 2")) is still possible even if the brake control device 100 completely fails, for example, due to a plug failure.

[0109] Figure 3 schematically shows a second exemplary embodiment of the brake control device 100' according to the present invention. In contrast to the first exemplary embodiment in Figure 3, the brake control device 100' includes a hydraulic fallback level due to driver access to the wheel brakes 8a, 8b. For this purpose, the brake control device 100' includes a master brake cylinder 2 that can be actuated by a brake pedal 51 and a simulation device 3 that interacts with the master brake cylinder 2.

[0110] The master brake cylinder 2 has a piston 15 in a housing (formed by a valve block) that borders the pressure chamber 17. When the master brake cylinder 2 / piston 15 is not operating, the pressure chamber 17 is connected to the pressure medium reservoir 4 via a radial bore formed by the piston 15 and a pressure equalization line section 41, and this connection can be interrupted by the relative movement of the piston 17 (when operating) within the housing. A parallel connection of throttles having a check valve 27 that closes toward the pressure medium reservoir 4 is located in the pressure equalization line section 41. This means that when the piston 15 is not operating, the pressure chamber 17 is connected to the pressure medium reservoir 4, preferably to the second chamber / return chamber 4b of the pressure medium reservoir, via one or more breather holes. This connection between the pressure chamber 17 and the pressure medium reservoir 4 is interrupted when the piston 15 is operating (fully).

[0111] The pressure chamber 17 houses a return spring 9, which positions the piston 15 in its starting position when the master brake cylinder 2 is not acting. The piston rod 24 couples the pivotal movement of the brake pedal 51 resulting from pedal operation with the translational movement of the piston 15 (master brake cylinder), and its operating range is preferably detected by a movement sensor 25, which has a redundant design. In this way, the corresponding piston movement signal is an indicator of the brake pedal operating angle, which represents the driver's desire to brake.

[0112] The pressure chamber 17 is connected to the isolation valve 23 by a hydraulic line 22. The hydraulic connection between the pressure chamber 17 and the brake circuit supply line 13 can be shut off by the isolation valve 23. A pressure sensor 20 connected to the line section 22 detects the pressure rise in the pressure chamber 17 due to the displacement of the piston 15. This pressure also represents a measurement of the driver's brake preference.

[0113] The simulation device 3 is hydraulically coupled to the master brake cylinder 2. The simulation device 3 essentially consists of a simulator chamber 29, a simulator rear chamber 30, and a simulator piston 31, which separate the two chambers 29 and 30 from each other. The simulator piston 31 is supported on a housing (valve block) by an elastic element 33 (e.g., a simulator spring) located within the simulator rear chamber 30. The simulator chamber 29 can be connected to the pressure chamber 17 of the master brake cylinder 2, for example, by an electrically actuated simulator enable valve 32.

[0114] For example, the pressure source 5 is exclusively activated by the second electronic control and adjustment unit 12, because redundancy in activating the pressure source 5 is not absolutely necessary for the master brake cylinder 2 / hydraulic fallback level.

[0115] The simulator enable valve 32 is assigned to the second electrical compartment B and is activated by the second electronic control and adjustment unit 12.

[0116] The pressure sensor 20 and the motion sensor 25 are also assigned to the second electrical compartment B. Signals from these sensors are supplied to the second electronic control and adjustment unit 12, which evaluates and processes them.

[0117] The remaining components of the brake control device 100' have already been described in relation to Figure 1 (brake control device 100).

[0118] Figure 4 schematically shows a second exemplary embodiment of the brake system according to the present invention. Figure 4 shows the system architecture of the brake system. The exemplary brake system comprises two hydraulically actuated wheel brakes 8a, 8b and two electromechanically actuated wheel brakes 80a, 80b, and an electro-hydraulic brake control device 100' as shown in Figure 3. Otherwise, the system architecture of the second exemplary embodiment corresponds to the system architecture of the first exemplary embodiment in Figure 2, except that the actuating device 300 (and its signal / data connection) is not provided, because the brake control device 100' comprises a master brake cylinder 2 having a brake pedal 51.

[0119] A common feature of the exemplary embodiments is that the hydraulic wheel brakes 8a, 8b are in each case connected to the brake control device 100(100') via two wheel lines 81a, 81b and 82a, 82b.

[0120] The first wheel lines 81a, 81b are used to increase the pressure, which is brought about by an electrically operated pressure source 5 (by pushing the piston 36 forward) through the open inlet valves 6a, 6b (with the closed outlet valves 7a, 7b). In this case, the start valve 26 is open and the separation valve 23 is closed.

[0121] Pressure release to release all of the wheel brakes 8a, 8b (for example, for normal brakes without antilock brake control) is usually brought about by means of drawing the pressure medium of the electrically operated pressure source 5 into the pressure chamber 37 by pulling the piston 36 back in the reverse direction, so to speak, through the first wheel lines 81a, 81b, the open inlet valves 6a, 6b, and the open start valve 26 (the separation valve 23 is closed).

[0122] In other words, in an anti-lock brake control system with wheel-specific pressure settings, (wheel) pressure release is achieved by closing the corresponding inlet valve and opening the corresponding outlet valve. This releases the pressure to the pressure medium reservoir 4 via the second wheel lines 82a, 82b.

[0123] This results in an annular flow (overall), where the pressure medium is sent from the pressure medium reservoir 4 to the pressure source 5 (while being replenished), through the inlet valves 6a, 6b and the first wheel lines 81a, 81b to the wheel brakes 8a, 8b, and back to the pressure medium reservoir 4 through the second wheel lines 82a, 82b and the outlet valves 7a, 7b. This annular flow is suitable for periodically purging the brake control device or brake system. Any air bubbles present are removed and discharged in the pressure medium reservoir 4.

[0124] This is preferably used for a method of initial filling / self-filling of a brake system. The brake control devices 100, 100' are further supplied pre-filled with pressure medium (brake fluid) prepared and held in the pressure medium reservoir 4 and installed in the vehicle. The wheel lines 81a, 81b, 82a, 82b of the wheel brakes 8a, 8b and the brake calipers are installed in a dry state, i.e., without filling. After all connections and electrical energy supply are made, the brake control devices 100, 100' can fill the previously dry wheel lines 81a, 81b, 82a, 82b and wheel brakes 8a, 8b via the annular flow described above.

[0125] Next, the success of the filling can be confirmed by the angle / position sensor 44 and the pressure sensor 19 of the pressure source 5, and if necessary, an error message can be output if a leak is detected.

[0126] The brake calipers of wheel brakes 8a, 8b, and their connections to the wheel lines, as well as the placement of the connections (pressure-increasing wheel connections 61a, 61b and pressure-relieving wheel connections 62a (62b)), must be designed so that the pressure medium (pressure-increasing wheel connections 61a, 61b) is supplied in a geometrically lower region, and the pressure medium (pressure-relieving wheel connections 62a, 62b) is released through a geometrically higher region so that no air pockets remain in the brake caliper. It is not necessary to install vent screws on the brake caliper.

[0127] Preferably, and especially for self-filling, the following method steps are performed. The wheel brakes, such as wheel brake 8b (FR), are purged (first purge cycle). a) Open the activation valve 26, close the separation valve 23, and open the outlet valve 7b assigned to the wheel brake. b) Operate the piston 36 of the pressure source 5 (in the forward direction / brake operating direction). Therefore, the volume of the pressure medium is pushed towards the pressure medium reservoir 4 through the open inlet valve 6b, the first wheel line 81b, the wheel brake (brake caliper) 8b, the second wheel line 82b, and the open outlet valve 7b. c) When the piston 36 of the pressure source 5 reaches its front end (right end in Figures 1 and 3) (which can be monitored by an angle sensor 44 or displacement sensor around the piston 36), the activation valve 26 closes and the piston 36 of the pressure source 5 retracts (i.e., in the opposite direction to the brake's operation), so that the pressure medium is replenished from the pressure medium reservoir 4 into the pressure chamber 37. d) Repeat steps a) to c) several times as needed.

[0128] Purge other wheel brakes, such as wheel brake 8a(FL) (second purge cycle). a) Open the activation valve 26, close the separation valve 23, and open the outlet valve 7a assigned to the wheel brake. b) Operate the piston 36 of the pressure source 5 (in the forward direction / brake operating direction). Therefore, the volume of the pressure medium is pushed towards the pressure medium reservoir 4 through the open inlet valve 6a, the first wheel line 81a, the wheel brake (brake caliper) 8a, the second wheel line 82a, and the open outlet valve 7a. c) When the piston 36 of the pressure source 5 reaches its front end (right end in Figures 1 and 3) (which can be monitored by an angle sensor 44 or displacement sensor around the piston 36), the activation valve 26 closes, and the piston 36 of the pressure source 5 retracts (opposite to the direction of brake operation), so that the pressure medium is replenished from the pressure medium reservoir 4 into the pressure chamber 37. d) Repeat steps a) to c) several times as needed.

[0129] Preferably, the following method steps for leak testing are performed. a) The isolation valve 23 is closed, the activation valve 26 is opened, and all other valves (6a, 6b, 7a, 7b, and 32, if necessary) remain shut off (i.e., the inlet valve is open and the outlet valve is closed). b) Construct a test pressure of, for example, 100 bar (using pressure source 5). In particular, the displacement pressure medium volume required to reach the test pressure is determined. c) Wait for a (short) stabilization period. d) Start the measurement phase. At least one of the following variables is monitored by one of the sensors of the brake control device: pressure medium volume change (e.g., by the angle / position sensor 44 of the pressure source 5), pressure drop (e.g., by the pressure sensor 19). No change in the pressure medium volume should occur during the specified measurement time. Alternatively, the pressure drop must not occur within the held pressure medium volume, or it must be compared to a specified test / comparison value. The displacement pressure medium volume required to reach the test pressure is compared to a specified value. e) End the leak test.

[0130] The self-replenishment process is completed by making the brake system usable.

[0131] In addition to self-filling, the brake control device or brake system according to the present invention enables further methods for operation, which restore or improve the function of the brake control device or brake system (e.g., active pressure medium cooling, self-venting).

[0132] When descending a mountain pass (for example, the Grossglockner Pass), the wheel brakes are subjected to a high thermal load. If overheating of the pressure medium (brake fluid) is suspected, advantageously, a corresponding purge process / purge cycle, such as in the case of self-filling, is performed for active cooling of the pressure medium. If the driver is not currently braking, the same purge process / purge cycle (steps a) to c)) is preferably performed for cooling of the pressure medium. If the driver is continuously braking, the purge process / purge cycle is incorporated into the braking process. For example, annular flow of pressure medium can be superimposed on normal braking, as can anti-lock brake control.

[0133] The following method steps are preferably performed, particularly in operating conditions that place a thermal load on the wheel brakes (active pressure medium cooling). The thermal load is also optionally monitored and detected by existing sensors, such as force sensors with temperature output located in electromechanical wheel brakes, according to the brake temperature model.

[0134] A purge cycle is performed if overheating of the pressure medium is suspected. Alternatively, both wheel brakes can undergo the purge process / purge cycle simultaneously or sequentially. In this case, the heated pressure medium is directed away from one or more hydraulically acting wheel brakes 8a, 8b (from the brake calipers) (through the second wheel lines 82a, 82b) to the pressure medium reservoir 4 (see purge cycle steps a), b). New, cold pressure medium flows in from the pressure medium reservoir 4 (see purge cycle step c). This avoids or prevents the formation of vapor bubbles.

[0135] To improve the effect, it is advantageous to provide second wheel lines 82a, 82b having an enlarged surface (for example, by cooling fins) or to form a heat sink.

[0136] If the purge process / purge cycle is performed while the brakes are applied, the brake torque of the electromechanically operated wheel brakes 80a, 80b (e.g., on the rear axle) will increase during the purge cycle by the amount of the brake torque deficit of the hydraulically operated wheel brakes 8a, 8b (e.g., on the front axle) to compensate. This means that the driver will not notice the change in deceleration.

[0137] Alternatively, the purge process / purge cycle can be performed in a tactilely recognizable manner so that the driver receives feedback about a dangerous condition. For example, insufficient braking torque in the hydraulically operated wheel brakes during a purge cycle is not compensated for by increasing the braking torque in the electromechanically operated wheel brakes 80a, 80b.

[0138] The above method of active pressure medium cooling offers the advantage of eliminating or delaying brake fluid replacement, or allowing wheel brakes 8a and 8b to be designed with less thermal margin, thus saving costs.

[0139] The aforementioned purge cycle is also a vent cycle (self-vent) that can be performed periodically (for example, according to a predetermined time schedule) and / or under certain conditions (for example, after regular multiple volume intake) by the brake system / brake control device.

[0140] For example, if steam bubbles form after a previous heat load when the system is switched off (so-called heat soak), venting in the workplace can be avoided after the brake system starts up because the brake system / brake control device automatically performs venting by running a purge cycle.

[0141] Brake fluid replacement in the workshop is also simplified by the brake control device or brake system according to the present invention. During the purge cycle, only the old brake fluid (old pressure medium) must be removed from the second chamber / return chamber 4b of the pressure medium reservoir 4, and new brake fluid (new pressure medium) must be filled into the first chamber / LAC chamber 4a of the pressure medium reservoir 4. Advantageously, the replacement cycle is performed via a fluid level alarm device.

[0142] The brake control devices 100, 100' according to the present invention offer the advantage that they can be provided to vehicle manufacturers who install brake control devices having unfilled wheel lines (81, 82) and wheel brake calipers (wheel brakes 8a, 8b) in a pre-filled state, and after the brake system is installed and started, the brake system or brake control device performs a self-filling process. Furthermore, the present invention may also encompass the following embodiments: 1. An electro-hydraulic brake control device (100, 100') for hydraulically actuated wheel brakes (8a, 8b), comprising an electrically activatable hydraulic source (5), inlet valves (6a, 6b) for each of the hydraulically actuated wheel brakes (8a, 8b), outlet valves (7a, 7b) for each of the hydraulically actuated wheel brakes (8a, 8b), and a pressure medium reservoir (4), wherein the electro-hydraulic brake control device (100, 100') comprises: An electrohydraulic brake control device (100, 100') for at least one of the hydraulically operable wheel brakes (8a, 8b), characterized in that the brake control device (100, 100') has a pressure-increasing wheel connection (61a, 61b) and a pressure-relieving wheel connection (62a, 62b). 2. An electro-hydraulic brake control device (100, 100') according to 1., characterized in that for at least one of the hydraulically actuated wheel brakes (8a, 8b), the pressure rise wheel connection (61a, 61b) is connected to the electrically activated hydraulic source (5) via the inlet valve (6a, 6b) assigned to the hydraulically actuated wheel brake (8a, 8b), and the pressure release wheel connection (62a, 62b) is connected to the pressure medium reservoir (4) via the outlet valve (7a, 7b) assigned to the hydraulically actuated wheel brake (8a, 8b). 3. The brake control devices (100, 100') for each of the hydraulically actuated wheel brakes (8a, 8b) are characterized by having a pressure-increasing wheel connection (61a, 61b) and a pressure-relieving wheel connection (62a, 62b), wherein for each of the hydraulically actuated wheel brakes (8a, 8b), the pressure-increasing wheel connection (61a, 61b) is connected to the electrically activated hydraulic source (5) via the inlet valves (6a, 6b) assigned to each of the hydraulically actuated wheel brakes (8a, 8b), and the pressure-relieving wheel connection (62a, 62b) is connected to the pressure medium reservoir (4) via the outlet valves (7a, 7b) assigned to each of the hydraulically actuated wheel brakes (8a, 8b). The electrohydraulic brake control device (100, 100') described in 1. or 2. above. 4. An electrohydraulic brake control device (100, 100') according to any one of 1. to 3. above, characterized in that the electrically activatable hydraulic source (5) is formed by a cylinder-piston device having a pressure chamber (37) and a piston (36), and the piston (36) can be pushed back and forth by an electromechanical actuator (35, 39). 5. An electrohydraulic brake control device (100, 100') according to any one of 1. to 4. above, characterized in that the electrically activatable hydraulic source (5) is connected to the brake line section (13) to which the inlet valves (6a, 6b) are connected via an electrically activatable activation valve (26). 6. The electrohydraulic brake control device (100, 100') according to 5. above, characterized in that the brake line section (13) can be connected to the pressure medium reservoir (4) via an electrically actuated separation valve (23). 7. The pressure medium reservoir (4) is characterized by having a first reservoir chamber (4a) and a second reservoir chamber (4b) separated from each other by a partition wall, wherein the electrically activatable hydraulic source (5) is connected to the first reservoir chamber (4a) of the pressure medium reservoir (4) via a replenishment line (42) and a check valve (53) that opens toward the pressure source, and one or more of the pressure relief wheel connections (62a, 62b) are connected to the second reservoir chamber (4b). An electro-hydraulic brake control device (100, 100') as described in any one of items 1 to 6 above. 8. A brake system for an automobile, comprising at least two hydraulically actuated wheel brakes (8a, 8b), and an electro-hydraulic brake control device (100, 100') comprising an electrically activatable hydraulic source (5), inlet valves (6a, 6b) for each hydraulically actuated wheel brake (8a, 8b), outlet valves (7a, 7b) for each hydraulically actuated wheel brake (8a, 8b), and a pressure medium reservoir, wherein the brake control device (100, 100') is connected to each hydraulically actuated wheel brake (8a, 8b) via first and second hydraulic connection elements (81a, 82a, 81b, 82b). 9. The brake system according to 8., characterized in that the brake control devices (100, 100') for each of the hydraulically operable wheel brakes (8a, 8b) have a pressure-increasing wheel connection (61a, 61b) and a pressure-relieving wheel connection (62a, 62b). 10. The brake system according to 8. or 9. above, characterized in that, for each hydraulically actuated wheel brake (8a, 8b), the first hydraulic connection elements (81a, 81b) connect the inlet valves (6a, 6b) assigned to the hydraulically actuated wheel brake (8a, 8b) to the pressure ports (801a, 801b) of the hydraulically actuated wheel brake (8a, 8b), and for each hydraulically actuated wheel brake (8a, 8b), the second hydraulic connection elements (82a, 82b) connect the outlet valves (7a, 7b) assigned to the hydraulically actuated wheel brake (8a, 8b) to the drain ports (802a, 802b) of the hydraulically actuated wheel brake (8a, 8b). 11. A brake system according to any one of claims 8 to 10, characterized in that a brake control device (100, 100') described in any one of claims 1 to 7 above is implemented. 12. A brake system according to any one of 8. to 11. above, having at least one wheel brake (80a, 80b) that can be actuated by an electromechanical actuator, and in particular having two wheel brakes (80a, 80b) that can each be actuated by an electromechanical actuator. 13. The brake system according to 12., characterized by comprising two wheel brakes (80a, 80b) each operable by an electromechanical actuator, wherein one of the wheel brakes operable by an electromechanical actuator (80a) is supplied with electrical energy by a first electrical energy source (PWR1), and the other wheel brake operable by an electromechanical actuator (80b) is supplied with electrical energy by a second electrical energy source (PWR2) independent of the first electrical energy source (PWR1). 14. A method for operating the brake system described in any one of 8. to 13. above, wherein the brake control device (100, 100') is used to perform a purge cycle. c) In particular, by activating the electrically activated hydraulic source (5) in the operating direction of the brake, the pressure medium moves through the first inlet valve of the inlet valve (6a, 6b), through the first hydraulically actuated wheel brake (8a, 8b) assigned to the first inlet valve, and through the outlet valve assigned to the first hydraulically actuated wheel brake to the pressure medium reservoir (4), or in the direction of the pressure medium reservoir (4), and in particular thereafter, d) In particular, by operating the electrically activated hydraulic source (5) in the opposite direction to the operating direction of the brake, the pressure medium is drawn from the pressure medium reservoir (4) to the electrically activated hydraulic source (5). In particular, steps a) and b) are repeated periodically. A method characterized by the following features. 15. The method according to 14., characterized in that the method is first performed for one of the hydraulically actuated wheel brakes (8b), and then for the other hydraulically actuated wheel brake (8a). 16. Next, a leak test of the brake system is performed by the brake control device (100, 100'), characterized in that the test pressure is increased and maintained by the electrically activatable hydraulic source (5), The method described in item 15 above. 17. In step a), in particular, before the electrically activated hydraulic source (5) is operated in the operating direction of the brake, the activation valve (26) located between the electrically activated hydraulic source (5) and the inlet valves (6a, 6b) is opened, the separation valve (23) located between the inlet valves (6a, 6b) and the pressure medium reservoir (4) is closed, and the outlet valve assigned to the first hydraulically operated wheel brake is opened. The method described in any one of the above 14-16. 18. The method according to any one of the above 14. to 17., characterized in that step a) is completed when the piston (36) of the electrically activatable hydraulic source (5) reaches a predetermined endpoint in the operating direction of the brake, and the activation valve (26) is closed before step b) is started. 19. The method according to any one of the above 14. to 18., in particular, characterized in that the method for filling the hydraulically operated wheel brake with a pressure medium is performed after the installation of the brake system. 20. The method according to any one of paragraphs 14 to 18, wherein the method for cooling the pressure medium is performed when a thermal load is detected on the basis of a monitoring method for the brake system or for one of the wheel brakes (8a, 8b, 80a, 80b). 21. The method according to 20., characterized in that the monitoring method is performed based on a brake temperature model and / or based on sensor data, in particular based on force sensor data based on temperature output. 22. The method according to any one of the above 14. to 18., in particular, characterized in that the method for venting the brake control device (100, 100') is repeated and / or performed under predetermined conditions.

Claims

1. An electrohydraulic brake control device (100, 100') for hydraulically actuated wheel brakes (8a, 8b), comprising an electrically activatable hydraulic source (5), inlet valves (6a, 6b) for each of the hydraulically actuated wheel brakes (8a, 8b), outlet valves (7a, 7b) for each of the hydraulically actuated wheel brakes (8a, 8b), and a pressure medium reservoir (4), wherein the electrohydraulic brake control device (100, 100') comprises: An electrohydraulic brake control device (100, 100') for at least one of the hydraulically operable wheel brakes (8a, 8b), wherein the brake control device (100, 100') has a pressure-increasing wheel connection (61a, 61b) and a pressure-relieving wheel connection (62a, 62b), the pressure medium reservoir (4) is characterized by having a first reservoir chamber (4a) and a second reservoir chamber (4b) separated from each other by a partition wall, the electrically activatable hydraulic source (5) is connected to the first reservoir chamber (4a) of the pressure medium reservoir (4) via a replenishment line (42) by a check valve (53) that opens toward the hydraulic source, and one or more of the pressure-relieving wheel connections (62a, 62b) are connected to the second reservoir chamber (4b).

2. The electrohydraulic brake control device (100, 100') according to claim 1, characterized in that for at least one of the hydraulically actuated wheel brakes (8a, 8b), the pressure rise wheel connection (61a, 61b) is connected to the electrically activated hydraulic source (5) via the inlet valve (6a, 6b) assigned to the hydraulically actuated wheel brake (8a, 8b), and the pressure release wheel connection (62a, 62b) is connected to the pressure medium reservoir (4) via the outlet valve (7a, 7b) assigned to the hydraulically actuated wheel brake (8a, 8b).

3. The brake control devices (100, 100') for each of the hydraulically actuated wheel brakes (8a, 8b) are characterized by having a pressure-increasing wheel connection (61a, 61b) and a pressure-relieving wheel connection (62a, 62b), wherein for each of the hydraulically actuated wheel brakes (8a, 8b), the pressure-increasing wheel connection (61a, 61b) is connected to the electrically activated hydraulic source (5) via the inlet valves (6a, 6b) assigned to each of the hydraulically actuated wheel brakes (8a, 8b), and the pressure-relieving wheel connection (62a, 62b) is connected to the pressure medium reservoir (4) via the outlet valves (7a, 7b) assigned to each of the hydraulically actuated wheel brakes (8a, 8b). The electrohydraulic brake control device (100, 100') according to claim 1 or 2.

4. The electrohydraulic brake control device (100, 100') according to claim 1 or 2, characterized in that the electrically activatable hydraulic source (5) is formed by a cylinder-piston device having a pressure chamber (37) and a piston (36), and the piston (36) can be pushed back and forth by electromechanical actuators (35, 39).

5. The electrohydraulic brake control device (100, 100') according to claim 1 or 2, characterized in that the electrically activatable hydraulic source (5) is connected to the brake line section (13) to which the inlet valves (6a, 6b) are connected via an electrically activatable activation valve (26).

6. The electrohydraulic brake control device (100, 100') according to claim 5, characterized in that the brake line section (13) can be connected to the pressure medium reservoir (4) via an electrically actuated separation valve (23).

7. A brake system for an automobile, comprising at least two hydraulically actuated wheel brakes (8a, 8b), an electrically activated hydraulic source (5), inlet valves (6a, 6b) for each hydraulically actuated wheel brake (8a, 8b), outlet valves (7a, 7b) for each hydraulically actuated wheel brake (8a, 8b), and an electro-hydraulic brake control device (100, 100') having a pressure medium reservoir, wherein for each hydraulically actuated wheel brake (8a, 8b), the brake control device (100, 100') has first and second hydraulic connection elements (81a, 8 A brake system characterized in that it is connected via 2a, 81b, 82b) to the hydraulically operable wheel brakes (8a, 8b), the pressure medium reservoir (4) having a first reservoir chamber (4a) and a second reservoir chamber (4b) separated from each other by a partition wall, the electrically activatable hydraulic source (5) is connected via a replenishment line (42) to the first reservoir chamber (4a) of the pressure medium reservoir (4) by a check valve (53) that opens toward the hydraulic source, and one or more pressure-relieving wheel connections (62a, 62b) are connected to the second reservoir chamber (4b).

8. The brake system according to claim 7, characterized in that the brake control devices (100, 100') for each of the hydraulically operable wheel brakes (8a, 8b) have a pressure-increasing wheel connection (61a, 61b) and a pressure-relieving wheel connection (62a, 62b).

9. The brake system according to claim 7 or 8, characterized in that, for each hydraulically actuated wheel brake (8a, 8b), the first hydraulic connecting element (81a, 81b) connects the inlet valve (6a, 6b) assigned to the hydraulically actuated wheel brake (8a, 8b) to the pressure port (801a, 801b) of the hydraulically actuated wheel brake (8a, 8b), and for each hydraulically actuated wheel brake (8a, 8b), the second hydraulic connecting element (82a, 82b) connects the outlet valve (7a, 7b) assigned to the hydraulically actuated wheel brake (8a, 8b) to the drain port (802a, 802b) of the hydraulically actuated wheel brake (8a, 8b).

10. The brake system according to claim 7 or 8, characterized in that the brake control device (100, 100') according to claim 1 or 2 is realized.

11. The brake system according to claim 7 or 8, having at least one wheel brake (80a, 80b) that can be actuated by an electromechanical actuator, and in particular having two wheel brakes (80a, 80b) that can each be actuated by an electromechanical actuator.

12. The brake system according to claim 11, characterized by comprising two wheel brakes (80a, 80b) each operable by an electromechanical actuator, wherein one of the wheel brakes operable by an electromechanical actuator (80a) is supplied with electrical energy by a first electrical energy source (PWR1), and the other wheel brake operable by an electromechanical actuator (80b) is supplied with electrical energy by a second electrical energy source (PWR2) independent of the first electrical energy source (PWR1).

13. A method for operating the brake system according to claim 7 or 8, wherein the brake control device (100, 100') is used to perform a purge cycle, a) in particular by operating the electrically activated hydraulic source (5) in the brake operating direction, thereby moving the pressure medium through the first inlet valve of the inlet valve (6a, 6b), through the hydraulically actuated wheel brakes (8a, 8b) assigned to the first inlet valve, and through the outlet valve assigned to the hydraulically actuated wheel brake to the pressure medium reservoir (4), or in the direction of the pressure medium reservoir (4), in particular thereafter, b) In particular, by operating the electrically activated hydraulic source (5) in the opposite direction to the operating direction of the brake, the pressure medium is drawn from the pressure medium reservoir (4) to the electrically activated hydraulic source (5), In particular, steps a) and b) are repeated periodically. A method characterized by the following features.

14. The method according to claim 13, characterized in that the method is first performed for one of the hydraulically actuated wheel brakes (8b), and then for the other hydraulically actuated wheel brake (8a).

15. Next, a leak test of the brake system is performed by the brake control device (100, 100'), the test pressure is increased and maintained by the electrically activatable hydraulic source (5), characterized in that The method according to claim 14.

16. In step a), in particular, before the electrically activated hydraulic source (5) is activated in the operating direction of the brake, the activation valve (26) located between the electrically activated hydraulic source (5) and the inlet valves (6a, 6b) is opened, the separation valve (23) located between the inlet valves (6a, 6b) and the pressure medium reservoir (4) is closed, and the outlet valve assigned to the hydraulically operated wheel brake is opened. The method according to claim 13.

17. The method according to claim 16, characterized in that when the piston (36) of the electrically activatable hydraulic source (5) reaches a predetermined endpoint in the operating direction of the brake, step a) is completed, and the activation valve (26) is closed before step b) is started.

18. In particular, the method according to claim 13, characterized in that the method for filling the hydraulically operated wheel brake with a pressure medium is performed after the brake system has been installed.

19. The method according to claim 13, characterized in that the method for cooling the pressure medium is performed when a thermal load is detected on the basis of a monitoring method for the brake system or for one of the wheel brakes (8a, 8b, 80a, 80b).

20. The method according to claim 19, characterized in that the monitoring method is performed based on a brake temperature model and / or based on sensor data, in particular based on force sensor data based on temperature output.

21. In particular, the method according to claim 13, characterized in that the method for venting the brake control device (100, 100') is repeated and / or performed under predetermined conditions.

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