DE102014109628A1 - Vehicle brake actuation system and method of operating the actuation system - Google Patents

Abstract

The invention relates to an actuating system for a vehicle brake, with an actuating device, such as a brake pedal, at least a first pressure source, in particular piston-cylinder unit (master cylinder), which is actuated in particular by means of the actuating device and a second pressure source, in particular piston-cylinder unit (DHK), with an electro-mechanical drive, wherein the pressure sources are each connected via a hydraulic line with at least one brake circuit to supply the brake circuit pressure medium and the vehicle brake to pressurize, and with a valve device for controlling the brake pressure. It is provided that by means of the second pressure source, in particular the second piston-cylinder unit (DHK), at least one brake circuit controlled pressure medium is supplied.

Description

The invention relates to an actuating system for a vehicle brake according to the preamble of claim 1 and a method for operating the actuating system according to the preamble of claim 10.

State of the art

The demands on brake systems are increasing. This applies in particular with regard to fault tolerance and good fallback level. If the brake booster fails, it should be achieved at the internationally predetermined foot force of 500 N, a delay greater than 0.64 g, which compared to the minimum requirement of the legislator of 0.24 significantly more means. An advantage of the high achievable delay, it is also that in case of failure of the brake booster, a red warning lamp, which irritates the driver, does not need to be controlled.

These requirements can be solved by brake-by-wire systems with path simulator. Here, the master cylinder (HZ) or tandem master cylinder (THZ) is designed for the fallback level in case of failure of the brake system. This is done by appropriate dimensioning with a small diameter. This results in higher pressures at a corresponding foot force. The necessary brake fluid volume for 0.64 g and corresponding pressure is relatively small compared to the maximum pressure at full vehicle deceleration and fading. The necessary volume can not fully apply a THZ even with a larger stroke. In the DE 10 2009 043 494 the applicant is proposed a solution with storage chamber, which feeds corresponding volume at higher pressures in the brake circuit. Furthermore, in the DE 10 2010 045 617 A1 the applicant described a further solution in which via appropriate valve and THZ control volume of the master cylinder is conveyed from the reservoir into the brake circuit. For vehicles with large volume intake, z. B. SUV and vans, the filling of the brake circuits during deceleration must be done even before the blocking pressure for high μ necessary. Both solutions make high demands on the tightness of the valves. In addition, with the additional filling of the brake circuits an interruption of the pressure build-up and small brake losses are connected.

In the DE 10 2011 111 369 the applicant is described a system with additional piston, which brings the required pressure medium volume and has the advantage that it is operated by the motor spindle and in the fallback level is not effective, ie the predetermined delay allows. The disadvantage here may under certain circumstances affect the correspondingly high forces, which load the spindle, the ball screw drive (KGT) and the bearings.

Another important consideration is the installation length. For braking systems, there are two different types of construction, the so-called "serial design" S and the "parallel design" P (hereinafter also referred to as "S system" or "P system"). This means that with the S system the main components (such as in DE 10 2011 111 369 ) the master cylinder THZ, motor with ball screwed gearbox KGT and auxiliary piston are arranged in one axis and the P-system (such as in DE 10 2012 222 897 A1 ), the master cylinder THZ in one axis and a piston-cylinder unit (plunger) for volume provision with motor are arranged in a laterally offset second axis.

The P-systems require less length, but are more complex and differ from the S-system in terms of fault tolerance. According to the DE 10 2013 111 974.3 the applicant is running a P-system with Doppelhubkolben and THZ, which does not meet all the requirements in the overall length and the valve circuit.

Object of the invention

The invention has for its object to provide a system with low structural complexity, short length and high reliability.

Solution of the task

The object of the invention is achieved by the features of patent claim 1.

Advantageous embodiments or embodiments of the invention are contained in the further claims, to which reference is also made here for description purposes for the sake of simplicity.

Advantages of the invention

With the solution according to the invention and its embodiments or refinements, an actuation system for a vehicle brake and a method for operating the actuation system with low construction costs, shortened overall length, reduced pressure load under extreme pedal forces and improved fault tolerance is created.

Furthermore, the invention or its embodiments / designs provide sufficient brake fluid volume with an additional prefill function.

Also, further potential for improvement, in particular starting from a braking device according to the patent application DE 10 2013 111 974.3 the applicant with partial P-type and DE 10 2014 102 536.9 with double-stroke piston DHK and prefilling function with S-design (to which reference is hereby made).

The in the registrations DE 10 2013 111 974.3 and DE 10 2014 102 536.9 the Applicant (the content of which is incorporated herein by reference) described solutions or their main features can be advantageously used or transmitted in the invention or its embodiments / embodiments, such as. B. fail-safe adaptive travel simulator with auxiliary piston and feed function in the fallback level, Vorfüllfunktion with their respective advantages such as short length, minimizing the effort, small Pedalanfangskraft, preferably comparable to the S-type.

The system with serial (S) arrangement of THZ and motor builds longer than the parallel (P) system where THZ and motor are arranged in separate axes. However, the P system is more complex with housings and valves. For the presented extensive functions and dimensioning the effort of the P-system should be reduced or also the functions should be extended.

The hydraulic connection of the double-stroke piston DHK with the secondary side of the push rod piston DK creates a similar function in the P-system as in the S-system, in which acts instead of the hydraulic pressure of the motor drive on the push rod piston DK. This brings many benefits, such. As the pistons are loaded with real pressure and piston travel, in particular the push rod piston DK error detection is easier, the volume flow in the brake circuits is variable by different valve arrangements. In addition, at least one isolation valve can be saved in the connection of the double-lift piston DHK. Likewise, the solenoid valves for the double-stroke piston DHK can be reduced and also the feed valve can be saved.

The piston-cylinder unit or the double-stroke piston can also be replaced by a pressure source with continuous delivery, e.g. an electric motor driven high pressure pump.

The valves used for brake circuit opening for pressure reduction are checked for leaks each time they are braked.

In addition, can be saved by alternately switching the valves EA, a pressure transducer, since the volume promotion by the Doppelhubkolben DHK compared to the pressure-volume curve and pressure detects both the volume uptake and leak or brake circuit failure.

The proposed in the S-version free travel for shortening the length and advantages in recuperation by the THZ engine and double-lift piston DHK is not operated, can also be used in the P version. This considerably reduces wear.

Description of the figures

Embodiments of the invention and their embodiments or embodiments are described in more detail in the following description of the figures.

Show it:

1 a system in P version with a minimum of effort;

1a an additional spring arrangement in the floating piston SK;

2 a system like 1 with simplified valve switching of a double-stroke piston DHK;

2a a system with a high-pressure pump, instead of a piston-cylinder unit;

3 a system like 1 with additional valves from the tandem master cylinder to the reservoir;

4 a P-type system with parallel double-stroke piston (DHK3) with three effective piston surfaces;

5 a system in P-design simplified with parallel double-stroke piston (DHK2) with two pistons;

5a a system with a simplified two-piston version; and

6 a P-type system with a parallel motor with drive belt.

This in 1 shown system represents a minimum of the effort for a minimum function. In this P-type construction, in which on a first axis A1, a piston-cylinder unit with a piston 16 (Auxiliary piston), another piston-cylinder unit (THZ) with push rod piston (DK) 12a and floating piston (SK) 12 lie and on a second axis A2, which is offset laterally or radially with respect to the first axis, a piston-cylinder unit with a Doppelhubkolben (DHK), a Ball-threaded gear (KGT), with spindle 5 and a drive motor 8th lie. The piston-cylinder unit with auxiliary piston can also be arranged on a parallel axis, such as in the patent application DE 10 2011 017 436.2 the applicant, in which the pedal ram is arranged on the central axis of the master cylinder and two auxiliary pistons on parallel offset axes. From working chambers of the further piston-cylinder unit (THZ), hydraulic lines HL1 and HL2 (without isolation valves) are connected via a valve block (VBL) to wheel brakes (not shown). From working chambers 10a . 10b the piston-cylinder unit with double-stroke piston (DHK) run line sections in which check valves V3, V4 are arranged and a common line section leading to two further hydraulic line sections in which (normally closed) switching valves EA are arranged to the hydraulic lines HL1 , HL2 or via the valve block VBL to the wheel brakes.

From the working chambers 10a and 10b of the double-stroke piston also run hydraulic lines (shown in phantom), are connected to the check valves S1 and S2, to a reservoir VB.

A Wegsimulatoreinrichtung with a travel simulator WS with piston, check valves RV0, RV1 and ÜV, and a diaphragm D and a solenoid valve WA is connected via a hydraulic line HL3 with a working chamber of the piston-cylinder unit with auxiliary piston 16 connected and corresponds to that in the patent applications DE 10 2013 111 974.3 and DE 10 2014 102 536.9 the applicant, to which reference is made in this regard, described Wegsimulator. The overpressure valve ÜV has two functions here: to reduce the throttle power in the normal function at high pedal speed and also in the fallback level RFE, so that the driver can implement the pedal force more quickly in pressure. The Wegsimulatoreinrichtung may suitably be arranged parallel to the THZ or in the valve block VBL.

The work spaces of the push rod piston DK and the floating piston SK are connected via hydraulic line sections HL1 and HL2 with the valve block VBL, wherein in these line sections no valves, in particular no switching valves are arranged (in contrast to the embodiments according to. 4 and 5 , When pressure buildup P _on means of Doppelhubkolbens DHK is initially a volume supply from the working chamber 10a of the double-stroke piston DHK in the working chamber 12c the pressure rod piston, ie on the back of the push rod piston DK of the piston-cylinder unit (THZ), so that the piston DK and SK build pressure in their pressure chambers and the lines HL1, HL2 and increase. Unlike the in 6 Thus, the volume or the pressure on the (not shown) pressure control valves in the valve block VBL is directed directly to the brake circuits (BK) and the wheel brakes of the piston-cylinder unit (THZ). Pedal position sensors 2a . 2 B determine the pressure in the brake circuits BK, which is effected by the drive of the double-stroke piston DHK and corresponding volume supply. The path simulator WS determines the pedal force characteristic. With a travel ΔWS, this travel simulator is controlled, which accounts for approximately 40% of the total travel of the pedal plunger. The volume supply can be changed in a first operating mode 1 in the corresponding path by entering volume by opening the two valves EA directly into the piston DK and SK associated brake circuits. In this case, the pistons DK and the SK remain in the position which is given by the path of the DK piston or the spring forces of the springs of the pistons DK and SK. By switching the valves EA is practically the same pressure on both sides of the piston SK and DK, so that the push rod piston DK on the pedal plunger (PS) 3 is applied, provided that the springs are adjusted accordingly. This can be defined with an additional spring, such as these, for example 1a is described.

With a progressive spring characteristic of the floating piston SK is achieved that the push rod piston DK remains at the Aussteuerweg ΔWS and the floating piston SK has a certain distance to the push rod piston DK.

The concern of the push rod piston DK to the pedal plunger 3 is preferably used with ABS function (operating mode 2). The ABS function can also be performed before the full Aussteuerweg ΔWS, since this is the max. Brake pressure z. B. 200 bar is controlled. The ABS function can be at low μ already at 10 bar and correspondingly small path of the pedal plunger 3 respectively. Again, the push rod piston DK on the pedal ram 3 issue. This requires further movement of the pedal plunger 3 additional counterforce due to friction and spring forces and compressive force on the pedal plunger 3 , This is quite advantageous because a small reaction of ABS to the pedal 1 is desired. This can be reinforced and modulated by varying the form Pvor by means of Doppelhubkolbens DHK.

The initial position of the floating piston SK with stroke reserve is of great importance for the "worst case" failure of the motor at low μ and subsequent positive μ jump. In this case, the floating piston SK can only supply sufficient volume if it has sufficient stroke and is not already present at the end of the housing. With the above vote, the pistons deliver SK and DK over the remaining stroke Volume, without it comes to a meeting of the pistons DK and SK, which then disadvantageously asymmetric braking pressures would arise.

To diagnose the position of the floating piston SK this can be performed with a not shown here sensor.

The pressure build-up P _on takes place as long as the pedal travel sensors 2a / 2 B pretend this to the motor control. Enough for high pressure level or volume, eg. As in fading, the volume of Doppelhubkolbens DHK in the forward stroke on the pressure relief valve S1 is not sufficient, so in the return stroke further volume promotion via the valve S2.

With this valve circuit of the suction valves S1 and S2 with pressure relief valve V3 and V4, no additional functions such as priming or pressure reduction P _{ab are} possible from the double-stroke piston DHK. These are described in the following figures with additional valve effort.

The eight valves required for pressure control (four inlet valves EV and four outlet valves AV) or alternatively four switching valves SV in multiplex mode MUX are contained in the valve block VBL. In the case of the ABS function, the double-stroke piston DHK with a forward stroke and return stroke acts permanently, since the volume taken _off via the outlet valves AV for the pressure reduction P must be reloaded. Is done by the pedal sensors 2a / 2 B Induced pressure reduction P _ab , this is also done via the valves AV in the return R. Preferably, this is done only via a valve AV, z. B. in the DK circuit with open valves EA.

For minimal effort and only one pressure transmitter DG belongs. It is possible to determine the pressure in both brake circuits with only one pressure transducer, since the floating piston 12 creates a pressure equalization between the two brake circuits.

This is independent of the switching position of the I / O valves. If a pressure build-up by the double-stroke piston DHK via the I / O valves directly into the brake circuits (eg ABS), it is possible by so-called alternating switching of the valves EA from the double-stroke piston DHK only in the respective brake circuit to promote so that the brake circuits never directly connected to each other.

The functions of the Doppelhubkolbens DHK and Wegsimulators WS are also in the patent applications DE 10 2010 045 617 A1 . DE 10 2013 110 188.7 . DE 10 2014 102 536.9 . DE 10 2014 107 112.3 the applicant described, to which reference is hereby made.

1a shows a spring arrangement with additional spring on the floating piston SK. Here is a spring housing 26 shown with floating piston spring F _SK , as is standard with tandem master cylinders THZ. In addition, here acts a arranged between the floating piston and spring housing spring F _X , which corresponds to the initial spring force of the conventional spring of the floating piston SK. This is known to be designed so that in this way the floating piston SK and push rod piston DK are put back and overcome the frictional forces. In contrast, the spring of the push rod piston DK is tied to a higher level of force. This is achieved with a corresponding progressive spring design of the floating piston SK, that at the same time the pressure build-up P _on both pistons DK and SK the Schnüffelloch 27 or the here not shown sniffer hole of the push rod piston DK (in 1a drawn in the open position) close. Also in this arrangement, this is the case by appropriate dimensioning of F _X , which has the same force as a conventional spring of the floating piston SK. In the normal case when pressure build P _on the distance between the floating piston SK and push rod piston DK is determined by the volume of the brake circuits, the pressure forces predominate the spring forces. In the above case arises by parallel connection of the valves EA almost the same pressure level, so that the pressure forces omitted and determine the respective acting spring and frictional forces the position of the piston. In the case described, the pressure rod piston DK should rest on the pedal plunger PS when the valves EA are connected in parallel, which is possible by spring adjustment.

At higher temperatures and no rain (thus normally no μ-jump is possible) operating mode 1 can be turned on, in which the parallel connection of valve EA does not occur and the floating piston SK and possibly also the push rod piston DK are moved to the stroke end. This has the advantage that the seals can be tested over the entire stroke, so that so-called "sleeping errors" are not possible.

2 shows the next stage of expansion with valves ESV in the line section HL4 and V _DK in the line section HL5 and SV5 in the line section HL6 and correspondingly extended functions.

As is known, feeding ES of additional volume into the brake circuits BK has great advantages in the fallback stage RFE, since the additional volume results in a higher pressure level or shorter pedal travel. However, the feeding ES requires that the valve V _{DK is} closed, so that a pressure equalization, which takes place when the valve EA is open, is prevented here when feeding ES. That's it Feeding via the valve EA arbitrarily in a brake circuit BK or both together possible. Because when feeding pressure forces from both the auxiliary piston 16 as well as the push rod piston DK on the pedal 1 act, is the feeding ES up to pressing z. B. from 20-25% of the blocking pressure z. B. 20-25 bar limited because of excessive pedal forces. After feeding ES, valve ESV is closed (operating mode 5). This is effective with 30-40% extra volume in the fallback RFE. Since the pressures in the fallback level RFE are lower than in the normal case, the valve V _DK can be designed correspondingly smaller in the switchable pressure range. This allows larger cross-sections or lower magnetic forces, which is cost-relevant.

Since the pressure rod piston DK is moved via the pedal plunger PS when the valve V _DK is closed, the valve SV5 is required in order to avoid negative pressure during the piston movement. When pressure is reduced P _from the valve V _{DK is} opened, and the volume passes through open valve ES and WA in the reservoir VB or via valves EA and AV also in the reservoir VB.

It can be here an idle LW between Pedalstößel 3 and the push rod piston DK are used, which brings in conjunction with valve ESV advantages, namely, no activation of the double stroke piston DHK and the engine for pressure build-up and pressure reduction or no piston actuation at recuperation and a length reduction.

The configuration of the push rod piston DK is here not according to standard as in the conventional THZ with two seals (the second seal is used in this to avoid leakage oil to the outside). In 4 and 6 For example, the push rod piston DK is connected to the double-stroke piston DHK as a 3-piston solution and advantageously has only one seal to its pressure chamber. Also this version with only one seal D1 can be used here without combination with the double-stroke piston DHK and without stepped piston in non-stepped cylindrical push rod piston DK. However, this requires a coupling of the spring housing 26 with the floating piston SK. This is necessary so that when pressure build P _on the piston SK, the piston DK in the normal case via the Schnüffelloch 27 of the push rod piston pulls, since here the volume of the double stroke piston DHK over the open Schnüffelloch 27 the push rod piston DK flows into the brake circuit assigned to the piston DK and the corresponding pressure acts on the brake circuit associated with the piston SK. Upon further pressure build-up and closed Schnüffelloch the pressure rod piston DK acts on the back of the piston DK associated brake circuit of the form and moves the piston DK to further pressure build-up on. This happens because in the first phase of the pressure build-up P _on the valve EA of the push rod piston DK is on until the respective volume of the Doppelhubkolbens both sniffer holes are closed, since the pressure of the push rod piston DK acts on the floating piston SK here. Subsequently, the valve EADK is closed again and the form Pvor acts on the push rod piston DK to build up pressure (operating mode 4)

During braking, there is often a phase of constant pressure (i.e., no pedal travel change) instead of the path simulator stage 1 (pressure range <30 bar). This is used to diagnose the leaks of all components, including the valves EA. Here valve VDK and valve EA is closed, the engine position is not changed, the valves ESV and WA are open, while no pressure reduction may occur in case of leakage of all components of the brake circuits. In particular, the valves EA are tested virtually every partial braking (80%) of all braking.

• – Bei Ausfall der Druckstangenkolben DK-Sekundärdichtung erfolgt im Gegensatz zu 1 und 3 kein Ausfall des Bremskraftverstärkers BKV. Auch bei Ausfall der DK-Dichtung in 2 fällt der Bremskraftverstärker BKV nicht aus. Die Funktion der Dichtung muss in Abständen geprüft werden, was z. B. bei Fahrzeugstillstand erfolgen kann.
• – geringere Kolbenreibung
• – geringere Belastung der Dichtungsmanschetten, da das Volumen beim Druckaufbau P_auf die Manschette öffnet
• – Ausführung mit Leerweg LW möglich, da das Einspeisevolumen am Hilfskolben über das Schnüffelloch direkt in den Druckstangen DK-Kreis gelangt.

Advantages of the execution according to 2 are:

• - In case of failure of the push rod piston DK secondary seal is in contrast to 1 and 3 no failure of the brake booster BKV. Even if the DK seal in 2 the brake booster BKV does not fail. The function of the seal must be checked at intervals, what z. B. can be done at vehicle standstill.
• - lower piston friction
• - Less stress on the gaskets, since the volume opens during pressure buildup P _on the cuff
• - Version with free travel LW possible because the feed volume at the auxiliary piston passes directly through the beak hole into the push rods DK circle.

As is known, the brake system must also be designed for maximum pedal forces, which make up more than a factor of 12 compared to the pedal force for achieving the blocking pressure. This affects the pressure load of the auxiliary piston, the housing of the auxiliary piston and valves ESV and WA. For this purpose, there is a simple solution with the existing valve circuit. If this case occurs and the low pressure level z. B. 200 bar designed valve WA opens at this pressure, so there is a pedal movement, which by the pedal sensors 2a / 2 B is measured. This leads to closing valve V _DK . The pedal ram acts on the push rod piston DK, it creates negative pressure on the secondary side of the push rod piston DK. On the primary side, the pressure of the push rod piston acts, which can be increased to 200 bar with the signal mentioned above. Thus, the high pedal force of two instead of a piston is compensated, resulting in a significant Reduces the pressure level at the above components (operating mode 5).

In case of failure of the path simulator, z. As a result of leakage, the function of the path simulator WS usually fails, ie the pedal force feedback is missing. It already became with the patent applications DE 10 2014 102 536.9 and DE 10 2014 107 112.3 Applicant executes that in the illustrated Wegsimulator arrangement with auxiliary piston 16 the possibility exists to switch to so-called. Follow-up brake power boost, so that as in the conventional vacuum brake booster, the pedal force contributes to the brake booster, where appropriate, longer pedal travel must be taken into account.

Also with the system 2 a failure of the path simulator is possible. After pressing the brake pedal acts in the first stage, only the return spring 18 to the pedal force, ie the pressure reduction P _ab is done as described by appropriate engine control via the pedal travel sensors 2a / 2 B , The failure of the travel simulator WS is not recognized until the valve WA should close at a certain pedal travel. If this is not the case, for. B. by failed seals, so this is detected by the force-displacement sensor KWS. Subsequently, the pressure build-up P _is normal to the signal of the pedal travel sensors 2a / 2 B , Here, volume or pressure on the back of the push rod piston DK and parallel to the prefilling of the brake circuits BK via both valves EA is controlled, ie it lacks only the counterforce of the travel simulator WS. A small counter force acts on the pedal ram. A larger counterforce can be generated by closing the valve V _DK . By vacuum then the full pressure force of the push rod piston DK acts on the pedal plunger PS 3 , By controlling the V _DK valve via pulse width modulation PWM, a counter force can be generated with the aid of the force-displacement measuring element KWS. An alternative here is closing the valves EA after priming. Subsequently, pedal force and motor control with corresponding volume supply act as a result of the brake booster (operating mode 7). In this case, the brake booster effect can be reduced if necessary. For pre-filling with this valve arrangement with valves V3 and V4 instead of an additional solenoid valve (see eg valve VF in 3 ) a pressure relief valve ÜV2 be used, for example, up to 30 bar prefilling with a large piston area and then flows over 30 bar volume for pressure equalization on the back of Doppelhubkolbens DHK flows. As a result, the large piston area of the double-stroke piston DHK acts up to 30 bar and, at> 30 bar, a smaller effective area for volume delivery due to pressure equalization.

For the application of the multiplex method (MUX) for pressure modulation, a valve AVMUX is required for the pressure reduction function in brake booster operation. In this case, with open valves EA volume for pressure reduction in the return pass unless a pressure build-up for additional volume with return stroke (RH) (fading) via the double-stroke piston DHK takes place. In normal braking mode this valve AVMUX is not necessary.

• a. die Schnüffellöcher wirken als Drossel, so dass der Staudruck vor dem Druckstangenkolben DK den DK-Kolben bewegt
• b. in der Rücklaufleitung vom Schwimmkolben SK zum Vorratsbehälter VB wird ein Ventil VVB eingeschaltet, welches im Fehlerfall schließt oder bei jedem Bremsvorgang kurzzeitig schließt bis ein entsprechender Hub des Kolbens DK erfolgt bei dem das Schnüffelloch des Schwimmkolbens SK sicher geschlossen ist
• c. eine Zusatzfeder am Druckstangenkolben DK mit Abstand zum Pedalstößel PS. Diese ist mit einer Kraft vorgespannt größer als die Vorspannung der SK-Feder, so dass der PS nach dem Abstand a den DK-Kolben bewegt und damit das Schnüffelloch am Druckstangenkolben DK schließt. Dann wirkt Pvor und der DK trifft auf den Schwimmkolben SK zum Druckaufbau im Schwimmkolben SK und bei Ausfall des DK-Bremskreises. Der BKV-Betrieb ist damit nicht gefährdet. Ohne Ausfall wirkt die Zusatzfeder nicht, da der DK-Kolben durch den Pvor-Druck bewegt wird, s. auch Betriebsmodus.

A failure of the secondary seal of the floating piston is also to be considered. Basically, in the normal case (no failure) the Pvor acts on the push rod piston DK and moves the piston DK to build up pressure in both brake circuits. For the above case, the volume would drain from the VDK via the beak hole of the push rod piston DK and the failed seal. This can be prevented by the following measures:

• a. The sniffer holes act as a throttle, so that the dynamic pressure in front of the push rod piston DK moves the DK piston
• b. in the return line from the floating piston SK to the reservoir VB a valve VVB is turned on, which closes in the event of a fault or briefly closes during each braking operation until a corresponding stroke of the piston DK takes place in which the sniffer hole of the floating piston SK is securely closed
• c. an additional spring on the push rod piston DK with distance to the pedal plunger PS. This is biased by a force greater than the bias of the SK spring, so that the PS moves after the distance a the DK piston and thus closes the Schnüffelloch on push rod piston DK. Then Pvor acts and the DK hits the floating piston SK to build up pressure in the floating piston SK and in case of failure of the DK brake circuit. The BKV operation is thus not endangered. Without failure, the auxiliary spring does not work because the DK piston is moved by the Pvor pressure, s. also operating mode.

2a shows an alternative to Doppelhubkolben DHK, with a driven by an electric motor pump. This can be a gear, cell or piston pump. The engine may conveniently be an EC motor. A piston pump does not need an additional check valve in contrast to a vane pump, since there are operating states with constant pressure without volume promotion, so that there is no backflow. If the pressure reduction for the brake booster BKV operation is not to take place via outlet valves AV of the ABS pressure control device VBL, this is done via valve AVMUX. With such a system, however, no priming VF and no multiplexing (MUX) as well as no pressure reduction as possible with a double-stroke piston DHK with valve AS.

3 shows a system with additional functions and valve alternatives. The suction valve SV5 can be avoided by a 3/2-V _DK- valve. In the normally open state of the double-stroke piston DHK and push rod piston DK, the return line is closed. In the fallback mode RFE, the connection of double-stroke piston DHK and push rod piston DK is disconnected in the switched state and that of the reservoir R is open.

The valve arrangement of the Doppelhubkolbens DHK with valves AS and V _F is from the DE 10 2014 107 112.3 the applicant known, it lacks the valves TV. The valve AS allows here a pressure reduction in open valves EA without opening the brake circuits BK valve AV. The valve ESV is closed and only in the fallback level 3 with electrical system failure open. The valve V _F is necessary for fast priming, which is particularly effective for a push rod piston DK after 2 ,

• 1. Die Druckquelle bzw. Hochdruckpumpe oder der Doppelhubkolben (Pvor) wirkt auf die Rückseite des Druckstangenkolbens DK, die Ventile EA sind geschlossen sowohl beim Vorhub wie ggf. auch beim Rückhub, der Pedalstößel 3 hat keinen Kontakt mit dem Druckstangenkolben DK;
• 2. Die Druckquelle bzw. Hochdruckpumpe oder der Doppelhubkolben (Pvor) wirkt auf den Druckstangenkolben und über Ventil EA direkt in die Bremskreise BK, wobei z.B. im ABS-Modus der Pedalstößel 3 in Kontakt mit dem Druckstangenkolben DK ist);
• 3. Der Pedalstößel 3 wirkt in der Rückfallebene direkt auf den Druckstangenkolben (gilt für System nach 1)(die Betriebsmodi 1–3 gelten für ein System gem. 1, 2 und 3);
• 4. Vorfüllen der Bremskreise BK oder erste Phase der Kolbenbetätigung bei System nach 2, Ventil EADK ist kurzzeitig geöffnet, der Schwimmkolben SK bewegt sich mit dem Druckstangenkolben DK infolge der Koppelung bis beide den Kolben zugeordnete Schnüffellöcher geschlossen sind durch entsprechende Steuerung des Hubes des Doppelhubkolbens oder Volumen und/oder Druckmessung im dem Kolben DK zugeordneten Bremskreis. DHK wirkt in Druckstangenkolben DK, der Pedalstößel 3 ist nicht in Kontakt mit dem Druckstangenkolben DK;
• 5. Die Druckquelle bzw. der Doppelhubkolben DHK wirkt über Ventil EA in die Bremskreise; Ventil VDK ist geschlossen, z.B. bei höchster Pedalkraft zusammen mit Pedalstößel 3;
• 6. Das Einspeisen von Volumen aus dem Hilfskolben wirkt in der Rückfallebene RFE 2 (Ausfall Motor) und 2a (Ausfall Motor bei low µ mit anschließendem positiven µ-Sprung) über Ventil EA in die Bremskreise BK; Ventil VDK ist geschlossen, Ventil ESV ist offen, der Pedalstößel 3 ist bei Leerweg LW erst nach diesem Leerweg in Kontakt mit dem Druckstangenkolben (gilt für Systeme nach 2 und 3);
• 7. Die Druckquelle bzw. der Doppelhubkolben DHK wirkt über Ventil VDK zusammen mit dem Pedalstößel auf den Druckstangenkolben. Das Ventil VDK steuert die Bremskraftverstärkung gegebenenfalls über KWS. Diese Anordnung ist als sog. Folge-Verstärker wirksam bei Ausfall des Wegsimulators WS;
• 8. Der Pedalstößel wirkt in der Rückfallebene mit und ohne Einspeisen zur Druckerzeugung auf den Druckstangenkolben.

All systems shown have in common that on the push rod piston DK to generate pressure both the pedal travel plunger 3 as well as the double-stroke piston DHK can act with volume promotion and corresponding pressure. By appropriate valve circuits, the following operating modes (BM) are possible:

• 1. The pressure source or high pressure pump or the Doppelhubkolben (Pvor) acts on the back of the push rod piston DK, the valves EA are closed both during the forward stroke and possibly also during the return stroke, the pedal plunger 3 has no contact with the push rod piston DK;
• 2. The pressure source or high pressure pump or the Doppelhubkolben (Pvor) acts on the push rod piston and via valve EA directly into the brake circuits BK, for example, in ABS mode, the pedal plunger 3 in contact with the push rod piston is DK);
• 3. The pedal ram 3 acts in the fallback level directly on the push rod piston (applies to system after 1 ) (operating modes 1-3 apply to a system acc. 1 . 2 and 3 );
• 4. Prime the brake circuits BK or first phase of piston actuation with system 2 , Valve EADK is briefly opened, the floating piston SK moves with the push rod piston DK due to the coupling until both pistons associated sniffer holes are closed by appropriate control of the stroke of Doppelhubkolbens or volume and / or pressure measurement in the piston DK associated brake circuit. DHK acts in push rod piston DK, the pedal ram 3 is not in contact with the push rod piston DK;
• 5. The pressure source or the double-stroke piston DHK acts via valve EA in the brake circuits; Valve VDK is closed, eg at maximum pedal force together with pedal tappet 3 ;
• 6. The feeding of volume from the auxiliary piston acts in the fallback level RFE 2 (Engine failure) and 2a (Motor failure at low μ followed by a positive μ jump) via valve EA into the brake circuits BK; Valve VDK is closed, valve ESV is open, the pedal ram 3 is at Leerweg LW only after this free travel in contact with the push rod piston (applies to systems according to 2 and 3 );
• 7. The pressure source or the double-stroke piston DHK acts via valve VDK together with the pedal plunger on the push rod piston. The valve VDK controls the brake boost if necessary via KWS. This arrangement is effective as a so-called sequence amplifier in case of failure of the path simulator WS;
• 8. The pedal plunger acts in the fallback level with and without feeds to generate pressure on the push rod piston.

• – Bei Normalbremsung (ohne Berücksichtigung von ABS) > 90 % sind die SK- und DK-Dichtungen mit dem direkt wirkenden Bremsdruck belastet, d.h. hier können keine „schlafenden Fehler“ entstehen (Ausnahme DK-Dichtung bei 2; der Verschleiß der Dichtung ist jedoch gering durch fehlende Belastung durch Druck und Schnüffelloch) Bei anderen Systemen wirkt auf den THZ nur der geringe Druck des Wegsimulators WS und birgt schlafende Fehler, wenn in der Rückfallebene eine wesentlich höhere Druckbelastung wirkt (ca. Faktor 2 bis 3). Noch extremer wirkt das, wenn die beschriebenen hohen Pedalkräfte auftreten.
• – ABS bewirkt eine kleine Pedalrückwirkung
• – Verkürzung der Baulänge durch parallele Anordnung von Motor und THZ
• – Der Wegsimulator WS mit dem Hilfskolben hat eine hohe Fehlersicherheit
• – Bei jedem Druckaufbau wird die Dichtheit der EA-Ventile getestet, was schlafende Fehler vermeidet
• – Bei Ausfall von Dichtungen erfolgt kein Ausfall des Bremskraftverstärkers BKV, ein wichtiger Fakt für den Normalfahrer, der trotz kleinerem HZ-Kolben bei Wegsimulator-Systemen bei Ausfall des Bremskraftverstärkers BKV Faktor > 4 höhere Pedalkräfte für dieselbe Abbremsung braucht
• – Mit geringem Mehraufwand von einem V_F-Ventil ist durch V_F ein schnellerer Druckaufbau P_auf möglich, was Bremswegverkürzung zur Folge hat
• – Da Trennventile TV nicht vorhanden sind bzw. entfallen wird das System einfacher und sicherer mit einigen Folgeeffekten wie beschrieben

The systems after 1 . 2 and 3 have the following common advantages:

• - For normal braking (without consideration of ABS)> 90%, the SK and DK seals are loaded with the directly acting brake pressure, ie no "sleeping errors" can occur here (exception DK seal at 2 ; However, the wear of the seal is low due to lack of pressure through pressure and Schnüffelloch) In other systems acts on the THZ only the low pressure of Wegsimulators WS and has dormant errors when in the fallback level a much higher pressure load acts (about factor 2 to 3 ). This is even more extreme when the described high pedal forces occur.
• - ABS causes a small pedal reaction
• - Shortening of the length by parallel arrangement of engine and THZ
• - The way simulator WS with the auxiliary piston has a high failure safety
• - Each time the pressure builds up, the tightness of the EA valves is tested, which avoids dormant errors
• - In case of failure of seals there is no failure of the brake booster BKV, an important fact for the normal driver, despite lower HZ pistons in Wegsimulator systems in case of failure of the brake booster BKV factor> 4 requires higher pedal forces for the same deceleration
• - With little additional effort of a V _F valve V _{F by} a faster pressure build-up P _on possible, which has Bremswegverkürzung result
• - As separation valves TV are not present or omitted, the system is easier and safer with some subsequent effects as described

Here, the effort is comparatively low to competing systems.

Below are the in the 4 to 6 described embodiments described. In these embodiments, isolation valves TV are disposed in the lines from the THZ to the valve block VBL. Furthermore, valves AS, VF and VDK are provided.

With the normal function, the auxiliary piston is activated when the pedal is pressed 16 , a force-displacement simulator KWS (cf. DE 10 2010 045 617.9 Applicant) and pedal travel sensors 2a . 2 B activated. These control the engine 8th on, over the spindle 5 with KGT 7 over the piston tappet 4 the double-stroke piston (DHK3) 10 with three or (DHK2) with two pistons or effective piston surfaces drives.

Volume delivery into the brake circuit is handled by the double-stroke piston DHK in the S-design and the P-design. The delivery volume is determined by the effective piston area and the piston stroke. In the S-design, the feed takes place during the preliminary stroke directly into the brake circuit and in the P-design via the EA valves in the brake circuit. During the return stroke, both the S-design and the P-design are pumped via the EA valves. If the so-called prefill VF occurs, then the effective piston area becomes larger by means of valve circuits. According to the different requirements for S-type and P-type, the double-stroke piston DHK is designed with three (DHK3) and / or two (DHK2) effective piston surfaces.

For use with the S-type design, the double-stroke piston DHK must feed the volume into the brake circuit during pressure build-up and also during the return stroke. Since here the piston with the seal D1 and D3 takes volume from the brake circuit, the ring surface must be sized accordingly. Furthermore, the effective piston area should be increased during priming. The volume from the annular surface is in this case pressed under the one-sided sealing sleeve, with the advantage that this already happens in the area of the Schnüffellochs and thus relieves the cuff. In addition, a piston movement with negative pressure generation in the brake caliper for adjusting the lining clearance is desired in order to reduce the residual friction torque and thus CO2. The seal D1 must be resistant to negative pressure. This results in a double-stroke piston DHK3 with three effective surfaces. This can also be used in a P-arrangement (eg acc. 4 ).

You can reduce a piston area with the double-stroke piston DHK2 without the need for negative pressure. Furthermore, in the double-stroke piston DHK, as in 5a shown and described below, to dispense with the shut-off valve. However, here the pressure reduction from the brake circuit BK must be done either via the ABS valves AV or an additional valve AUX.

The volume promotion in the brake circuit correlates with the volume intake as a function of the pressure for the individual wheel circuits or the entire brake system. One speaks of the pv characteristic. Therefore, the correlation can be used for the diagnosis of the brake circuit (satisfaction condition, leak, BK failure). But also to the mentioned pressure control for the pressure build-up Pauf as well as the pressure reduction Pab. It is possible to provide a "partial multiplex" (partial MUX), the multiplex method being used only for pressure build-up or pressure reduction, as described in the patent application DE 10 2005 055 751 the applicant is described in more detail, to which reference is made in this regard.

Preferably, the piston tappet is designed to be flexible in bending in order to reduce the lateral force on the double-stroke piston (DHK) during a spindle stroke. 10 to create. The torque support is not executed here and corresponds to that in the DE 10 2012 103 506 the applicant described torque support, to which reference is made so far. The functions of the double-stroke piston (DHK3) 10 with suction valves S1 and S2 with shut - off valve AS correspond to those in DE 10 2013 111 974 the Applicant described functions. Will the double-stroke piston (DHK) 10 actuated via the motor drive, so the volume of brake fluid from the pressure chamber 10b conveyed via the valves EA in the brake circuits DK and SK. The valve AS remains open, the valve VF is open. In order to monitor the bleeding state of the brake circuits BK, the delivery volume is checked with the pressure in the brake circuits BK via pressure transmitter DG. If it does not comply with the pressure-volume curve, an I / O valve is alternately closed and the further pressure build-up is monitored. If detected BK failure the corresponding valve EA remains closed. Simultaneously with the engine operation, the separating valves TV are closed.

Is after the end of the Vorhubes the Doppelhubkolbens 10 DHK the desired pressure level is not reached, as in the application DE 10 2013 111 974.3 described in the applicant, the return stroke, in which the valve AS closed and the valve VF is open. Is that in the application DE 10 2013 111 974.3 claimed VF function required, so the valve AS and the valve VF is closed during the pre-stroke. If now the ABS function is required, then z. For example, the pressure control of the prior art with intake valves EV and outlet valves AV for pressure reduction (see valve block VB). In this case, the volume for the pressure reduction via return lines R arrives Reservoir VB. To reduce the pressure difference at the valve EV, it is possible, the pressure difference at the EV z. B. only 20% above the blocking pressure of the so-called. High wheel einsteuern. Due to the lower differential pressure can be at the same max. Pressure gradient of the valve cross-section are chosen to be larger, so that during rapid braking the back pressure lower and the so-called. Time-to-lock is smaller.

Alternatively, instead of four intake valves EV and four exhaust valves AV, the MUX pressure control with four shift valves SV may be employed. One of the many advantages is precise pressure control, in that the piston (DHK) controls the corresponding volume in the wheel circle. This method can also be used here for pressure build-up Pauf via valve EV.

• a. Nach Durchlaufen des Leerweges LW trifft der Pedalstößel 3 auf den Kolben 12a und wirkt dann weiter auf die HZ-Rückstellfeder 23a und zusätzlich vier Dichtungen, da die Feder 23 vorgespannt ist. Dies bedeutet insgesamt sechs Dichtungen. Mit dem Motoranlauf werden die Ventile TVDK und TVSK geschlossen und ein HLF-Ventil zum Rücklauf R zum Vorratsbehälter VB geöffnet, damit keine zusätzliche Druckkraft auf den Kolben 12a und Pedalstößel 3 wirkt. Die Kraft-Weg-Charakteristik bestimmt neben der genannten Reibung nur der Wegsimulator WS, der auch adaptiv sein kann wie in der DE 10 2014 102 536.9 der Anmelderin beschrieben.
• b. Über das geöffnete VDK-Ventil gelangt beim Vorhub des Doppelhubkolbens 10 entsprechend der Motorsteuerung Bremsflüssigkeitsvolumen aus dem Druckraum 10b (auch aus dem Druckraum 10a über geöffnete Ventile AS und VF) in einen von der Rückseite des DK-Kolbens 12a begrenzten Druckraum 12c, somit wirkt dieser wie die vorgenannte S-Bauform gemäß DE 10 2010 045 617.9 der Anmelderin, da bei offenem Ventil AS nur das Volumen des vorderen Kolbens zur Volumenförderung beiträgt, wie dies auch in den Patentanmeldungen DE 10 2013 111 974.3 und DE 10 2014 102 536.9 der Anmelderin beschrieben ist, auf die diesbezüglich hier Bezug genommen wird. Somit wirkt hier auf die Pedalanfangskraft nur die Reibungskraft von zwei Dichtungen, wobei die Druckkomponente des kleinen Pedalstößeldurchmessers mit < 15 % vernachlässigt werden kann. In dieser Phase sind zunächst beide Ventile TV offen, vorteilhaft wird das TVSK nach dem Überfahren des Schnüffellochs 12b des Kolbens 12a geschlossen. Dies kann indirekt über die Bewegung des DHK-Kolbens 10 über den Motorsensor festgestellt werden. Nach Schließen von TVSK bleibt TVDK offen, das EADK ist zu, EASK ist offen, damit das Volumen des DHK nach geschlossenem TVSK in den Bremskreis SK gelangt. Damit sind beide BK annähernd auf demselben Druckniveau, welches bei höheren Drücken nicht mehr der Fall ist wegen der Dichtungsreibung im DK-Kolben 12a. Zum Druckausgleich kann hierbei das EADK geöffnet werden, somit wirkt der Druck des Doppelhubkolbens (DHK) 10 mit gleichem Druckniveau in beide Bremskreise BK. Ein möglicher Bremskreis-Ausfall wird diagnostiziert durch je einen Druckgeber DG pro Bremskreis BK und die Volumenförderung des Doppelhubkolbens DHK, welche mit der Druckvolumenkennlinie des Bremskreises BK korrelieren muss. Ist dies nicht der Fall, so wird die Volumenzufuhr über das jeweilige Ventil EA abgeschaltet. Soll Vorfüllen für einen Ausgleich des Belaglüftspiels oder einen schnellen Druckanstieg erfolgen, so werden die Ventile AS und VF geschlossen, so dass eine große effektive Kolbenfläche des Doppelhubkolbens DHK 10 voll zur Wirksamkeit kommt. Dabei wirkt beim Doppelhubkolben DHK3 eine große Kolbenfläche bestehend aus dem vorderen Kolben (Druckraum 10b) und dem Ringkolben (Druckraum 10a), was über den Kolbenweg eine größere (z. B. um den Faktor 3) Fördermenge ergibt, als nur mit dem vorderen Kolben bzw. dessen Wirkfläche. Beim Doppelhubkolben DHK2 wirkt der Kolben mit der Dichtung D2. Beim Vorfüllen wird ein Druckausgleich auf die Hinterseite des Kolbens verhindert durch Sperren des Ventils VF gemäß 5.

When pressed for movement of the brake pedal 12 become the redundant pedal travel sensors 2a and 2 B operated in a function to be defined by the OEM, which is the engine 8th and thus determine the pressure build-up and the brake booster (BKV). Between pedal rams 3 and DK piston is a small free travel LW installed so that the pedal initial force is small. This is determined by the restoring forces of the springs, friction in the guides, Pedalwegsensoren and essentially by the friction of the seals, which are pressure-dependent. This total friction, which acts on the pedal, is conceptually very different. In the S system according to the DE 10 2010 045 617.9 The Applicant act essentially only two seals and the return spring, the HZ pistons with springs only in the fallback level RFE, as moved by the control signal of the pedal travel sensors in the brake booster (BKV) operation, the HZ pistons away from the pedal plunger. For other systems, eg. B. DE 10 2012 205 962 , four seals work. In the shown 4 There are two ways of controlling a. and b.

• a. After passing through the free travel LW hits the pedal plunger 3 on the piston 12a and then acts on the HZ return spring 23a and in addition four seals, as the spring 23 is biased. This means a total of six seals. With the engine start the valves TVDK and TVSK are closed and an HLF valve to the return R to the reservoir VB is opened, so that no additional pressure force on the piston 12a and pedal rams 3 acts. In addition to the mentioned friction, the force-displacement characteristic determines only the displacement simulator WS, which can also be adaptive as in the DE 10 2014 102 536.9 the applicant described.
• b. The open VDK valve reaches the forward stroke of the double-stroke piston 10 according to the engine control brake fluid volume from the pressure chamber 10b (also from the pressure room 10a via opened valves AS and VF) into one of the back of the DK piston 12a limited pressure chamber 12c , so this acts like the aforementioned S-type construction according to DE 10 2010 045 617.9 the Applicant, since with open valve AS only the volume of the front piston contributes to volume promotion, as in the patent applications DE 10 2013 111 974.3 and DE 10 2014 102 536.9 the applicant is described, to which reference is made in this regard. Thus, only the frictional force of two seals acts on the pedal initial force, whereby the pressure component of the small pedal plunger diameter can be neglected with <15%. In this phase, initially both valves TV are open, advantageous is the TVSK after crossing the Schnüffellochs 12b of the piston 12a closed. This can be done indirectly via the movement of the DHK piston 10 be detected via the engine sensor. After closing TVSK TVDK remains open, the EADK is closed, EASK is open, so that the volume of DHK after closed TVSK in the brake circuit SK arrives. Thus, both BK are approximately at the same pressure level, which at higher pressures is no longer the case because of the seal friction in the DK piston 12a , To equalize the pressure, the EADK can be opened, thus the pressure of the double-stroke piston (DHK) acts. 10 with the same pressure level in both brake circuits BK. A possible brake circuit failure is diagnosed by a respective pressure transmitter DG per brake circuit BK and the volume of the Doppelhubkolbens DHK, which must correlate with the pressure volume characteristic of the brake circuit BK. If this is not the case, the volume supply via the respective valve EA is turned off. If priming for a compensation of the lining clearance or a rapid increase in pressure take place, then the valves AS and VF are closed, so that a large effective piston area of the double-stroke piston DHK 10 fully effective. The double-stroke piston DHK3 has a large piston area consisting of the front piston (pressure chamber 10b ) and the annular piston (pressure chamber 10a ), which results in a larger (eg by a factor of 3) delivery rate via the piston travel, than only with the front piston or its effective area. With the double-stroke piston DHK2, the piston acts with the seal D2. During priming, pressure compensation to the rear of the piston is prevented by locking the valve VF in accordance with 5 ,

The control according to b. has many advantages, eg. B. the seals of the HZ-piston are always loaded with real pressure. In systems in which the HZ pistons are used for the waysimulator WS, only the WS-pressure which is only about 30% of the brake pressure in the brake circuit BK is effective.

Furthermore, when the path simulator (WS) control point is reached, the valve TVDK closes approximately 40% of the pedal travel, together with the WA valve of the travel simulator WS, which is already closed in stage 2 of the travel simulator WS. Ie. in step 1 of the flat characteristic, the valve WA is open, with only the return spring 18 and the seal friction on the auxiliary piston 16 essentially acts on the pedal force. In stage 2, the valve WA is closed, ie the Wegsimulatorkorkben with its spring characteristic acts on the pedal.

As you know, the pressure in the travel simulator WS can be very high when a strong driver fully on the pedal occurs. Here, pressures> 300 bar can occur, which load housings and seals. This high pressure is measured with the pressure transducer DG, since the high pedal force acts on the DK piston when z. B. at high pressure> 200 bar the valve WA opens mechanically. In this case, the valve VDK can be closed and the valve ESV opened. This affects both the pressure forces of DK pistons 12a as well as auxiliary piston 16 on the brake pedal. Thus, the pressure load in the range of 200 bar when the valve WA opens. This can be solved by a current control of the normally open valve.

The pressure reduction in the brake booster (BKV) mode is effected by the return movement of the double-stroke piston 10 DHK by additional pressure reduction via AV valves in the return R because the additional volume of VF is not compensated for the return stroke of the double-stroke piston DHK.

Below are the fallback levels RFE to describe.

RFE1 in case of failure of the path simulator WS z. B. Leakage. In this case, the counterforce is missing because no pressure in the path simulator WS arises. This is known to be detected by the force-displacement simulator KWS as in the DE 10 2014 102 536 the applicant is described, if the progressive force increase of the path simulator WS in stage 2 after a certain pedal travel (s. DE 10 2014 102 536 ) acts or fails. In this case, the pedal ram hits 3 on the DK piston 12 , which means a force change and is measured by the force-displacement simulator KWS. In this case, the motor control and volume control takes place on the back of the DK piston 12a via the valve VDK in function of the KWS signal. In this case, the brake booster BKV acts like a conventional brake booster with pedal force assistance as a follow-up brake booster (Fo-BKV). The advantage here is compared to the S-type, that acts in subsequent brake booster the same short pedal travel, but with some discontinuous characteristic.

In an optimization of the sensitivity of the force-displacement simulator KWS could be dispensed with the waysimulator WS.

RFE 2 at engine failure at low μ, DK piston is at the path simulator control point with high pedal force and subsequent positive μ jump. As already in the DE 10 2013 111 974.3 the applicant, to which reference is made in this regard, is here volume with auxiliary piston via open valve ESV and EADK fed into the brake circuit BK of DK pistons.

RFE3 at engine and vehicle power failure. The valves ESV, VDK, WA are open here, the valves EADK, EASK closed. The pedal plunger acts on DK pistons 12 , The pressure is generated conventionally via the pedal force.

It is also conceivable, the S-type design according to the DE 10 2014 102 536.9 , to which reference is made, to be designed so that the motor is parallel and via a toothed belt drive, for. B. accordingly DE 10 2011 050 587 on which ball-threaded gear KGT acts.

5 is different too 2 by omission of valve HLF by only driving method b. is used and a Doppelhubkolben (DHK2) 15 with two pistons. In addition, this valve can be omitted if VF is dispensed with. In 5 this valve is drawn for the function VF and is in contrast to 4 between the valve AS and the double-stroke piston 15 positioned.

This double piston DHK2 or DHK3 gem. 4 can also be in a P-type design DE 10 2012 222 897 A1 be used.

For hydraulic systems, care must be taken that they are pressure balanced when the vehicle is stationary. This is the case with the system 4 and 5 the case, since all valves (AS, VF, VDK, ESV, WA) to return and also the sniffer holes of the HZ pistons are open.

The difference of the double-stroke piston (DHK3) according to 4 with three pistons for double-stroke piston (DHK 2) according to 5 lies in two advantages. The double-stroke piston DHK3 can be used in the pressure chamber 10b Create negative pressure if the D1 seal is resistant to negative pressure. This is advantageous in the Lüftspieleinstellung the brake piston with negative pressure as in the DE 10 2008 051 316.4 the applicant is described, to which reference is made here in this regard. The second advantage is the failure safety in case of failure of the seals D1-D3. If one of the three seals fails, pressure can be built up in the forward stroke, the BKV function is retained. Besides, the failure is diagnosed. This is important for autonomous driving / braking, because with single fault the function must be maintained.

5a shows with the double-stroke piston DHK a simplification of the 2-piston version. Here is dispensed with the shut-off valve AS by two pressure relief valves V1 and V2 are used. The pestle 4 acts via seal D3 directly on the piston. If the return stroke is not used for further volume promotion in the brake circuit, but pressure reduction is to take place on withdrawal of the brake pedal, this can be done by opening the ABS-AV valve or by an additional AVX valve in the double-lift piston DHK circuit.

In 6 a vehicle brake or an actuating system for this purpose is shown, with in series successively arranged first, second and third piston-cylinder units.

Parallel to this, ie with spatially offset central axis, is in the range of the first piston-cylinder unit (Doppelhubkolben) a drive with electric motor 8th arranged, the drive from the output spindle on a rotating nut and from there to the spindle 5 a ball-threaded transmission 7 done by means of a toothed belt. The remaining elements of the Betätigungssytems largely correspond to those in the 4 and 5 shown, so that a more detailed description is omitted here. A parallel arrangement of the motor with belt drive can also at a in the 4 and 5 be represented in the rest P arrangement of the actuating system advantageous.

LIST OF REFERENCE NUMBERS

1

brake pedal

2a

Pedal travel sensors Master

2 B

Pedal travel sensors slave

3

pedal tappet

4

plunger rod

5

spindle

6

Motorsensor

7

KGT

8th

EC motor

9

storage

10

Double Stroke Pistons (DHK3)

10a

 annulus

10b

 pressure chamber

10c

 pressure chamber

11

reservoir

12

SK-piston

12a

 DK-piston

12b

 Sniffer hole DK

15

Double Stroke Pistons (DHK2)

16

auxiliary piston

18

Pedal return spring

23

HZ-return spring

23a

 HZ-return spring

24

shut-off valve

25

DHK housing

26

spring housing

27

breather hole

D

Aperture for throttling

S1

Suction valve 1

S2

Suction valve 2

S5

Suction valve 5

V3

Pressure relief valve

V4

Pressure relief valve

R

Return to the VB

RV0

Check valve 0

RV1

Check valve 1

WS

travel simulator

OSR

Pressure relief valve

ÜV2

Pressure relief valve for priming

Hiko

auxiliary piston

LW

leerweg

RFE

Fallback

LS

clearance

KWS

Force-displacement sensor

BK

brake circuit

DG

thruster

VF

priming

BKV

Brake booster

Fo-BKV

Follow-BKV

VB

reservoir

VBL

manifold

F _SK

Return spring SK

F _X

additional spring

AV

Exhaust valve ABS

EV

Inlet valve ABS

P _before

Form from the DHK

FODK

Additional spring on the piston DK

VVB

Valve to the reservoir VB

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009043494 [0003]
• DE 102010045617 A1 [0003, 0044]
• DE 102011111369 [0004, 0005]
• DE 102012222897 A1 [0005, 0086]
• DE 102013111974 [0006, 0012, 0013, 0033, 0071, 0072, 0072, 0074, 0082]
• DE 102014102536 [0012, 0013, 0033, 0044, 0055, 0074, 0074, 0080, 0080, 0084]
• DE 102011017436 [0031]
• DE 102013110188 [0044]
• DE 102014107112 [0044, 0055, 0061]
• DE 102010045617 [0066, 0074, 0074]
• DE 102005055751 [0070]
• DE 102012103506 [0071]
• DE 102012205962 [0074]
• DE 102011050587 [0084]
• DE 102008051316 [0088]

Claims (17)

Operating system for a vehicle brake, with an actuating device, such as a brake pedal, at least one first pressure source, in particular piston-cylinder unit (master cylinder), which can be actuated in particular by means of the actuating device and a second pressure source, in particular piston-cylinder unit (DHK), with an electro-mechanical drive, wherein the pressure sources are each connected via a hydraulic line with at least one brake circuit to supply the brake circuit pressure medium and the vehicle brake to pressurize, and with a valve device for controlling the brake pressure, characterized in that means of the second Pressure source, in particular the second piston-cylinder unit (DHK) during the forward and return stroke, at least one brake circuit controlled pressure medium can be fed. Actuating device according to claim 1, characterized in that no valves, in particular no separating valves are arranged in at least one hydraulic line from the first pressure source, in particular piston-cylinder unit to the valve device. Actuating device for a vehicle brake, with an actuating device, such as a brake pedal, at least a first pressure source, in particular piston-cylinder unit (master cylinder), which is actuated by means of the actuating device and a second pressure source, in particular piston-cylinder unit (DHK) with an electro-mechanical drive, wherein the pressure sources are each connected via a hydraulic line with at least one brake circuit to supply at least one brake circuit pressure medium and the vehicle brake to pressurize and with a valve device for controlling the brake pressure, in particular according to claim 1 or 2, characterized in that between the second pressure source, in particular a pressure chamber ( 10b ) of the Doppelhubkolbens (DHK) and the first pressure source, in particular one from the back of the piston (DK) of a first piston-cylinder unit ( 12 . 12a . 12b ) limited pressure space ( 12c ) is a hydraulic connecting line, in which at least one solenoid valve (VDK), in particular for controlling different operating modes, is arranged. Actuating device according to one of the preceding claims, characterized in that in which the first and second piston-cylinder unit with the valve means (VBL) connecting the first and second hydraulic line solenoid valves (EA) are arranged and that in only one of these lines or the from the second piston-cylinder unit to the valve device (VBL) leading hydraulic line (HL1, HL2), preferably in the line (HL2), a pressure sensor (DG) is arranged. Actuating device according to one of the preceding claims, characterized in that in the pressure chambers ( 10a . 10b ) of the piston-cylinder unit (DHK) interconnecting hydraulic lines check valves (V3, V4) or solenoid valves (AS, VF), in particular for controlling the pressure medium inlet and outlet, are arranged. Actuating device according to claim 5, characterized in that in a hydraulic line connecting the hydraulic lines with check valve, a pressure relief valve (ÜV2) is connected for the pre-filling. Actuating device according to one of the preceding claims, characterized in that in one the second piston-cylinder unit (DHK) with a pressure chamber ( 12c ) of the first piston-cylinder unit and a path simulator (WS) connecting hydraulic line (HL5) a solenoid valve (ESV) is connected (operating mode 6 and 8). Actuating device according to one of the preceding claims, characterized in that a supplementary spring (Fx) is arranged on a piston (SK) of the first piston-cylinder unit. Actuating device according to one of the preceding claims with a third piston-cylinder unit (auxiliary piston), characterized in that to reduce the pressure in the third piston-cylinder unit, in particular at maximum force of the actuating device, a counterforce by means of a piston (SK) of the second piston-cylinder unit is applied. Actuating device according to one of the preceding claims, characterized in that the push rod piston (DK) has only one seal and that in particular the push rod piston (DK) and the floating piston (SK), in particular by means of a spring housing of the push rod piston (DK) are coupled together. Actuating device according to one of the preceding claims, characterized in that a diagnostic circuit for testing seals, in particular seals of the push rod piston (DK), the floating piston (SK) and / or the Doppelhubkolbens (DHK) is provided. Actuating device according to one of the preceding claims, characterized in that the first pressure source, in particular Piston-cylinder unit, a third pressure source, in particular piston-cylinder unit (auxiliary piston) is connected upstream. Actuating device according to one of the preceding claims, characterized in that the second pressure source has a motor-driven pump with associated solenoid valve (AVMUX) and / or check valve (RV). Actuating device according to one of the preceding claims, characterized in that a Wegsimulatoreinrichtung is provided, which cooperates in particular with the piston-cylinder unit (auxiliary piston). Method for operating a brake device, in particular according to one of the preceding claims, characterized in that the rear side of a piston, a first piston-cylinder unit by means of a pressure source, in particular second of a piston-cylinder unit, pressure medium is supplied. A method according to claim 15, characterized in that by means of pressure source, in particular a piston-cylinder unit, pressure is generated in brake circuits without the use of isolation valves. A method according to claim 15 or 16, characterized in that by means of at least one solenoid valve different operating modes, such as priming, ABS, max. Pedal force or max. Control of the way simulator, fallback level to be controlled.

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