DE102015221228A1 - Brake control device for a hydraulic vehicle brake system and brake system - Google Patents

Abstract

Brake control device (200) for a hydraulic motor vehicle brake system having at least two brake circuits, comprising for each of the brake circuits an input pressure port (1) and an associated output pressure port (3), each brake circuit having a first hydraulic connection (11a, 11b) between the input pressure port (1 ) and the output pressure port (3) is provided, in which a, in particular currentless open running, analog controllable, first valve (5) is arranged, an electrically controllable pressure source with a suction side (41) and a pressure side (42) is provided, the suction side (41) is connected to the inlet pressure port (1) and the pressure suction side (42) is connected to the outlet pressure port (3), and a second hydraulic connection (11a, 2a, 2b) between the inlet pressure port (1) and the outlet pressure port (FIG. 3) is provided, in which in the direction of the outlet pressure port (3) towards opening first Rücksc Lifting valve (6) is arranged, as well as brake system with such an actuating device (100), which hydraulically between an actuating device (100) with brake master cylinder master cylinder (99) and an electrically controllable pressure modulation device (300) for setting wheel-individual brake pressures with an electrically controllable pressure source (310 ) is arranged.

Description

The invention relates to a brake control device for a hydraulic motor vehicle brake system having at least two brake circuits and a brake system according to the preamble of claim 10.

Known conventional vehicular hydraulic brake systems often include wheel brakes (e.g., hydraulically actuated disc brakes), an electro-hydraulic brake slip ride stability control (HECU) unit, and a brake actuator with a vacuum brake booster. The electronic controller of the electro-hydraulic control unit is usually designed according to the so-called "fail-silent" principle, i. after a detected error, the control unit is switched completely or partially electrically inoperative. One way of actuating the brake system by the driver, e.g. without electrical support or interference possibility, but remains.

Known electrohydraulic control units for ABS / ESP automotive brake systems include two input pressure ports, i. for each of the two brake circuits, an input pressure port, four wheel-specific output pressure ports, a pressure control valve assembly for adjusting wheel-specific brake pressures at the outlet pressure ports, a low pressure accumulator per brake circuit for receiving pressure fluid discharged from the wheel brakes and a dual-circuit return pump.

It is to be expected that in the future also vehicle brake systems will be used, which are suitable for automated moving vehicles. These braking systems must be basically externally controllable systems. This means that a brake request via electronic or electrical control signals can be requested and implemented by the system without the driver's intervention. For safety reasons, a sufficiently high availability of the brake system or the externally controllable braking function must be ensured.

It is an object of the present invention to provide a brake system which ensures the necessary for automated driving availability of brake pressure supply. In particular, a simple and therefore inexpensive brake control device is to be provided, which can be arranged between an actuating device with a brake pedal-actuated master cylinder and an electrically controllable pressure modulation device with pressure modulation valves and an electrically controllable pressure source, and which constitutes a hydraulic amplifier with low flow resistance.

This object is achieved by a brake system according to claim 10 and a brake control device according to claim 1.

The invention is based on the idea that the brake control device for each of the brake circuits comprises an input pressure port and an associated output pressure port, each brake circuit is a first hydraulic connection between the input pressure port and the output pressure port is provided, in which an analog controllable first valve is arranged, an electrically a controllable pressure source is provided, whose suction side is connected to the inlet pressure port and the pressure suction side to the outlet pressure port, and a second hydraulic connection between the inlet pressure port and the outlet pressure port is provided, in which a in the direction of the outlet pressure port opening towards first check valve is arranged.

By the second hydraulic connection with the first check valve, a connection with low flow resistance between the inlet pressure port and the output pressure port of the brake control device is provided so that suction of pressure medium from the master cylinder of the actuator into the electrically controllable pressure modulation device by the brake control device with the lowest possible hydraulic resistance is possible ,

Preferably, no further valve is arranged in the second hydraulic connection in addition to the first check valve.

Preferably, the brake control device does not include a connection for a pressure medium container or pressure medium reservoir. The pumps of the brake control device thus suck pressure medium via the inlet pressure ports, e.g. from the master cylinder.

In order to achieve a low flow resistance, the first check valve preferably has a large passage cross-section. Particularly preferably, the first check valve has a passage cross-section of at least 3 to 4 mm.

Preferably, a second check valve, which opens in the direction of the outlet pressure port, is connected in parallel with the first valve, which is structurally designed in the first valve. This second, integrated check valve has a smaller passage cross-section than the individually executed, first check valve. Therefore, the second check valve is insufficient for low flow resistance from input pressure port to output pressure port.

The first check valve is preferably connected in parallel to the first valve and the pump connected in parallel, so that regardless of the switching state of the first valve, a suction of a sufficiently large pressure medium volume flow from the upstream actuator in the downstream pressure modulation device via the second hydraulic connection with the first check valve of the brake control device can be done , In other words, the first check valve bypasses the first valve and also the pump.

According to one embodiment of the invention, a normally closed closed, second valve is provided in the hydraulic connection between the suction side of the pump and the inlet pressure port. The second valve protects the pump from damage. As such, pumps are known which have improved pump suction performance, but whose seals can be damaged by sustained or repeated pressurization on the suction side. By the normally closed second valve, the pump is protected from pressurization by the driver.

The first check valve is then preferably connected in parallel to the pump and the second valve, i. through the second hydraulic connection with the first check valve, the series connection of the second valve and the pump is bridged. Thus, the second valve does not act as a flow resistance during the suction of pressure medium via the second hydraulic connection with the first check valve.

For ease of testability of the brake system, the brake control device is preferably designed as a structural unit in the form of a brake control device with an electronic control unit and a hydraulic control unit. In this case, the electronic control unit is designed to control the electrically controllable components of the brake control device, in particular for controlling the pumps and the first valves, and possibly the second valves.

Preferably, the pumps of the brake control device are driven together by an electric motor.

Preferably, at least one first pressure detection device is provided per brake circuit, which detects the pressure at an output pressure port.

The invention also relates to a brake system according to the preamble of claim 10, which comprises a brake control device according to the invention.

Preferably, the input pressure ports of the brake control device are connected to the master cylinder and the output pressure ports of the brake control device are connected to the pressure modulation device. Particularly preferably, the input pressure connections of the brake control device are connected to the master brake cylinder without the interposition of a valve, in order to minimize flow resistance during intake from the master brake cylinder.

The pressure modulation device is preferably designed for ease of testability as a structural unit in the form of a brake control device with an electronic control unit and a hydraulic control unit. In this case, the electronic control and regulating unit is particularly preferably designed to control all the electrically controllable components of the hydraulic control and regulating unit of the pressure modulation device.

The actuating device preferably comprises a brake booster connected upstream of the master brake cylinder. The brake booster is particularly preferably carried out electrically actuated. Advantageously, it is a known per se, electrically actuated vacuum brake booster.

Preferably, the brake system is powered from at least two independent electrical energy sources to achieve high availability of the brake system.

Further preferred embodiments of the invention will become apparent from the subclaims and the following description with reference to figures.

Show it

1 a first embodiment of a brake system according to the invention with a first exemplary brake control device, and

2 A second embodiment of a brake system according to the invention with a second brake control device according to the invention.

In 1 is a first embodiment of a brake control device according to the invention 200 shown for a hydraulic vehicle brake system. Brake control device 200 is designed with two circuits. Each circle includes brake control device 200 an input pressure port 1 , for example, for connection to a pressure source 100 , and an outlet pressure port 3 , for example, for (indirect) connection with wheel brake 151a . 151b respectively. 151c . 151d ,

The exemplary brake control device 200 includes a pump assembly with a pump 50 each circle, which are driven by an electric motor M common, and a first electrically controllable, advantageously normally open, valve 5 each circle.

Every pump 50 includes a suction side 41 and a print page 42 , The following will be one of the circuits of the brake control device 200 described, the other circle is structured accordingly.

The first valve 5 , which is designed analogously controllable and, for example, normally open without power, is in a hydraulic connection 11 between the input pressure port 1 and the outlet pressure port 3 with the pipe sections 11a and 11b arranged. The first valve 5 is one in the direction of the outlet pressure port 3 opening check valve 10 connected in parallel, the constructive in the valve 5 is formed and therefore has a small passage cross-section.

The print side 42 the pump 50 is over line sections 4b and 15 with the associated line section 11b and thus the associated outlet pressure port 3 connected.

The suction side 41 the pump 50 is about the pipe sections 4a . 4c with the associated inlet pressure connection 1 connected. According to the first embodiment of the 1 is the suction side 41 directly, ie without the interposition of a valve, with the inlet pressure connection 1 connected.

Furthermore, over the line sections 11a . 2a . 2 B another hydraulic connection between the inlet pressure connection 1 and the outlet pressure port 3 provided in which one in the direction of the outlet pressure port 3 opening check valve 6 is arranged. This has in comparison with the check valve 10 a large passage cross section. The check valve 6 Thus, for example, on the one hand the first valve 5 connected in parallel and to the other of the pump 50 connected in parallel or the check valve 6 bridges the first valve on the one hand 5 and on the other hand, the pump 50 , The hydraulic connection with check valve 6 serves to connect a low flow resistance between pressure input 1 and pressure output 3 the brake control device 200 to accomplish. This is particularly advantageous to a suction of pressure medium of the downstream brake system or the downstream pressure modulation device 300 with the lowest possible hydraulic resistance through the brake control device 200 to enable.

According to the first embodiment, a pressure sensor (a pressure detecting device) is provided. 20 per circuit provided which the pressure at the outlet pressure port 3 detected. Furthermore, for at least one of the circuits, a pressure sensor (a pressure detection device) 21 provided, which the pressure of the inlet pressure port 1 detected.

Brake control device 200 includes a hydraulic unit (hydraulic control unit, HCU) and an electronic control unit (ECU).

According to the first embodiment of a brake system according to the invention (see 1 ) is the brake control device (pump valve module) 200 hydraulically between an actuator 100 and a pressure modulation device 300 arranged.

The exemplary actuator or pressure source 100 includes a master cylinder 99 , which is actuated by a brake pedal via a push rod, a brake booster upstream of the master cylinder 150 and a master cylinder 99 assigned, under atmospheric pressure medium reservoir 140 ,

The twin-circuit master cylinder 99 comprises two pistons arranged one behind the other, which delimit two hydraulic pressure chambers, wherein each pressure chamber has two wheel brakes 151a . 151b respectively. 151c . 151d assigned. The first piston is coupled to the brake pedal and can be operated by the driver. The pressure chambers are pressure equalization lines to the pressure medium reservoir 140 assigned. Each pressure chamber of the master cylinder 99 is with one of the inlet pressure connections 1 the brake control device connected.

Brake control device 200 is preferably a main brake system in the form of a pressure modulation device 300 for setting wheel-individual brake pressures upstream with an electrically controllable pressure source. According to the in 1 illustrated embodiment, this is a known per se, ESC module (ESC: Electronic Stability Control).

Pressure modulation device 300 comprises a hydraulic unit (hydraulic control unit, HCU) and an electronic control unit (ECU), which for controlling the electrically controllable components of the pressure modulation device 300 , in particular the valves and the electrically controllable pressure source 350 is trained.

Pressure modulation device 300 is for example designed as a conventional ESC module. The ESC module essentially comprises a dual-circuit motor-pump unit 310 and each circuit a low-pressure accumulator 311 and two electrically controllable valves 312 . 313 and an electrically controllable pressure modulation device 320 with wheel-specific intake valves 352a - 352d and exhaust valves 352a - 352d for adjusting wheel-specific brake pressures for the wheel brakes 151a - 151d ,

The inlet connections of the inlet valves 352a . 352b ; 352c . 352d are pairwise by means of line sections 323a . 323b supplied with pressures called Modulatorprordrücke. The outlet connections of the outlet valves 353a . 353b ; 353c . 353d are in pairs to each one of the hydraulic low-pressure accumulator 311 connected.

The inlet valves 352a - 352d is ever one in the direction of the wheel brake 151 closing, unspecified check valve connected in parallel.

The low pressure accumulator 311 are each about one in the direction of the low-pressure accumulator 311 closing check valve 331a . 331b with the associated hydraulic pump 350 connected. The two pumps 350 are driven by means of a common electric motor M.

One electromagnetically operated, normally closed (SG) 2/2-way valve 313 is between a brake circuit pressure line 324a . 324b and the suction port of the pump 350 connected. The pressure connections of the pumps 350 are to the Modulatorvordruckordleitungen 323a . 323b connected.

In the brake circuit pressure lines 324a . 324b is ever a normally open and analog controllable valve 312a . 312b arranged. The valves 312a . 312b is ever one in the direction of the wheel brakes 151 opening check valve 317a . 317b connected in parallel.

At the brake circuit pressure line 324b is a preferably redundant executed pressure sensor 319 intended.

The pumps 350 of the ESC module 300 suck pressure fluid volume via the brake control device 200 from the actuator 100 at. In this case, the lowest possible hydraulic resistance of advantage, because the lower the hydraulic resistance for the pump 350 when sucking, the faster this pressure medium can promote and thus build up brake pressure. Serve for this purpose, the second compounds of the brake control device 200 with the first check valves 6 ,

The hydraulic components of the exemplary brake system are therefore in three electro-hydraulic or hydraulic units 100 . 200 . 300 arranged, wherein the brake control device 200 forms the middle of the modules.

Preferably, each of the electronic control units (ECU), that is, the ECU of the pressure modulation device 300 and the ECU of the brake control device 200 , powered by its own electrical power supply (not shown).

2 a second embodiment of a brake system according to the invention is shown. The second embodiment of the brake system differs from the first embodiment of the brake system in 1 only by the brake control device. Therefore, only the differences in the brake control device will be discussed below. This in 2 illustrated second embodiment of a brake control device according to the invention largely corresponds to the first embodiment of the 1 , In contrast to the first embodiment, each circle of the brake control device 200 a second electrically controllable, advantageously normally closed executed valve 7 intended. Valve 7 is in the hydraulic connection between the suction side 41 the pump 50 and the input pressure port 1 (ie in the line section 4a and 4c ) arranged. Accordingly, valve locks 7 in the de-energized state, the pressure medium volume flow from the inlet pressure port 1 to the pump suction side 41 from. Through the second valve 7 becomes the pump 50 protected against damage.

check valve 6 is according to the second embodiment, on the one hand, the first valve 5 connected in parallel and to the other of the pump 50 with second valve 7 connected in parallel. check valve 6 serves to valve 7 and pump 50 as well as the analog valve 5 to bridge and thus a connection with low flow resistance between the input pressure port 1 and the outlet pressure port 3 the brake control device 200 to provide a pressure medium suction of the downstream pressure modulation device 300 by the brake control device 200 to facilitate.

The hydraulic layout of the brake control device according to the invention allows a flow with optimized hydraulic resistance. This is particularly advantageous to allow suction of pressure medium of the downstream brake system (the pressure modulation device) with the lowest possible hydraulic resistance by the brake control device.

With a relatively low hydraulic effort of using a check valve 6 per brake circuit is a direct connection with low flow resistance between input pressure port 1 and outlet pressure port 3 achieved, which is the otherwise to be flowed through hydraulic resistances of the analog valve 5 or the pump 50 and possibly the valve 7 bypasses.

The brake control device (the pump-valve module) preferably amplifies input pressure (e.g., master cylinder pressure) applied to the input and outputs it to an electrically controllable pressure modulation device, in particular to an ESC (Electronic Stability Control) module.

The brake control device is preferably driven by a separate electronic control unit (ECU), which is independent of the function of the electronic control unit (ECU) of the pressure modulation device (e.g., the ESC electrohydraulic module). This provides the redundancy required for automated driving of electronically controlled brake pressure delivery.

A brake control device according to the invention is preferably used as a supplement to a main brake system, which already has an electrically controllable pressure generator or pressure source 350 has.

The brake control device preferably includes the necessary for redundancy own electronic control unit (ECU) and a second electrically controllable pressure generator or pressure source 50 , so that throughout the braking system two independent ECUs and electrically controllable pressure generator 350 . 50 available.

The exemplary brake control devices 200 do not include a connection for a pressure medium container or pressure medium reservoir.

In electrically reinforced brake systems, special attention is paid to availability. High availability is preferably achieved by supplying the brake system with at least two independent electrical energy sources. In addition, components at risk of possible failures, such as ECUs (electronic control units) and actuators (e.g., electrically controllable pressure sources), are preferably at least two-fold.

Claims (14)

Brake control device ( 200 ) for a hydraulic motor vehicle brake system having at least two brake circuits, comprising for each of the brake circuits an input pressure port ( 1 ), in particular for connection to a brake pedal actuable pressure source ( 100 ), and an associated outlet pressure port ( 3 ), in particular for connection to a wheel brake, wherein each brake circuit • a first hydraulic connection ( 11a . 11b ) between the input pressure port ( 1 ) and the outlet pressure port ( 3 ) is provided, in which a, in particular currentless open executed, analog controllable, first valve ( 5 ) is arranged, • an electrically controllable pressure source, in particular pump ( 50 ), with a suction side ( 41 ) and a print page ( 42 ) is provided, wherein the suction side ( 41 ) with the input pressure port ( 1 ) and the pressure suction side ( 42 ) with the outlet pressure port ( 3 ), and • a second hydraulic connection ( 11a . 2a . 2 B ) between the input pressure port ( 1 ) and the outlet pressure port ( 3 ) is provided, in which a in the direction of the outlet pressure port ( 3 ) opening first check valve ( 6 ) is arranged. Brake control device according to claim 1, characterized in that the brake control device ( 200 ) does not comprise a connection for a pressure medium container or pressure medium reservoir. Brake control device according to claim 1 or 2, characterized in that in the second hydraulic connection ( 11a . 2a . 2 B ) next to the first check valve ( 6 ) no further valve is arranged. Brake control device according to one of claims 1 to 3, characterized in that the first check valve ( 6 ) has a large passage cross section, in particular a passage cross section of at least 3 to 4mm. Brake control device according to one of claims 1 to 4, characterized in that the first valve ( 5 ) in the direction of the outlet pressure port ( 3 ) opening second check valve ( 10 ) is connected in parallel, which in particular a smaller passage cross-section than the first check valve ( 6 ) owns. Brake control device according to one of claims 1 to 5, characterized in that the first check valve ( 6 ) the first valve ( 5 ) is connected in parallel and the pump is connected in parallel. Brake control device according to one of claims 1 to 6, characterized in that the suction side ( 41 ) of the pump ( 50 ) with the input pressure port ( 1 ) via a second, normally closed valve ( 7 ) is separably connected. Brake control device according to claim 7, characterized in that the first check valve ( 6 ) second valve ( 7 ) and pump ( 50 ) is connected in parallel. Brake control device according to one of claims 1 to 8, characterized in that the brake control device is designed as a structural unit in the form of a brake control device with an electronic control unit (ECU) and a hydraulic control unit (HCU), wherein the electronic control and control unit for controlling the pump or pumps ( 50 ) and of the first valve or valves ( 5 ), and in particular of the second valve or valves ( 7 ), is trained. Brake system for a motor vehicle for actuating hydraulically actuatable wheel brakes ( 151a - 151d ), with an actuating device ( 100 ) with a brake pedal operable master cylinder ( 99 ) with at least two pressure chambers for connecting one respective brake circuit, in particular one of the actuating device ( 100 ) associated under atmospheric pressure pressure fluid reservoir ( 140 ), • an electrically controllable pressure modulation device ( 300 ) for adjusting wheel-specific brake pressures with an electrically controllable pressure source ( 310 ), and in particular with at least one inlet valve ( 352a - 352d ) and an outlet valve ( 353a - 353d ) for each wheel brake ( 151a - 151d ), and • a brake control device ( 200 ), which hydraulically between the actuator ( 100 ) and the pressure modulation device ( 300 ), characterized in that the brake control device ( 200 ) For each of the brake circuits, an input pressure port ( 1 ) and an associated outlet pressure port ( 3 ), wherein each brake circuit • a first hydraulic connection ( 11a . 11b ) between the input pressure port ( 1 ) and the outlet pressure port ( 3 ) is provided, in which a, in particular currentless open executed, analog controllable, first valve ( 5 ) is arranged, • an electrically controllable pressure source, in particular pump ( 50 ), with a suction side ( 41 ) and a print page ( 42 ) is provided, wherein the suction side ( 41 ) with the input pressure port ( 1 ) and the pressure suction side ( 42 ) with the outlet pressure port ( 3 ), and • a second hydraulic connection ( 11a . 2a . 2 B ) between the input pressure port ( 1 ) and the outlet pressure port ( 3 ) is provided, in which a in the direction of the outlet pressure port ( 3 ) opening first check valve ( 6 ) is arranged. Brake system according to claim 10, characterized in that the inlet pressure connections ( 1 ) of the brake control device ( 200 ), in particular without the interposition of a valve, with the master cylinder ( 99 ) and that the outlet pressure connections ( 3 ) of the brake control device ( 200 ) with the pressure modulation device ( 300 ) are connected. Brake system according to claim 10 or 11, characterized in that the pressure modulation device ( 300 ) is designed as a structural unit in the form of a brake control device with an electronic control unit (ECU) and a hydraulic control unit (HCU), wherein the electronic control unit designed to control the components of the hydraulic control unit is. Brake system according to one of claims 10 to 12, characterized in that the actuating device ( 100 ) a master cylinder ( 99 ) upstream, in particular electrically actuated, brake booster ( 150 ), in particular vacuum brake booster comprises. Brake system according to one of claims 10 to 13, characterized in that it comprises a brake control device ( 200 ) according to any one of claims 2 to 9.

Images