DE102014107112A1 - 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, in particular a brake pedal, at least one (first) piston-cylinder unit which is connected via a hydraulic line to the vehicle brake (brake circuit) to supply the brake circuit pressure medium and the vehicle brake with To pressurize and with a drive for the piston-cylinder unit. According to the invention, by means of at least one, in particular stepped, piston (10) of the piston-cylinder unit (10, 10a, 10b) controlled by the brake circuit in both piston movement directions, in particular forward and return stroke, pressure medium can be 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 11.

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 is also that a red warning lamp, which irritates the driver, does not have 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 plunger for volume delivery 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 short length and high reliability to create.

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 made here.

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 shortened overall length and improved fault tolerance are provided.

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 partly 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).

• – fehlersicherer adaptiver Wegsimulator mit Hilfskolben und Einspeisfunktion in der Rückfallebene
• – DHK
• – fehlersicherer DHK
• – Vorfüllfunktion

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
• - DHK
• - fail-safe DHK
• - Pre-filling function

In addition:

• - short length
• - Minimizing the effort
• - Small pedal initial power, as comparable as possible to the S-type

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 P-type with parallel double stroke piston (DHK3) with three pistons;

2 P-type simplified with parallel double stroke piston (DHK2) with two pistons;

2a a simplified two-piston version; and

3 P-type with a parallel motor with drive belt.

1 shows the P-type construction, in which in the first axis, a piston-cylinder unit with a piston 16 (Auxiliary piston), another piston-cylinder unit (THZ) with DK piston 12a and SK pistons 12 lie and in the second axis, which is laterally or radially offset with respect to the first axis, a piston-cylinder unit with a Doppelhubkolben (DHK), a ball-threaded transmission (KGT), with spindle 5 and a drive motor 8th lie. From working chambers of the further piston-cylinder unit (THZ) are hydraulic lines, in which the brake circuits associated solenoid valves TV are connected via a valve block (VBL) with (not shown) wheel brakes. Of working chambers of the piston-cylinder unit with Doppelhubkolben run hydraulic lines, in which the brake circuits associated with solenoid valves EA are arranged, also via the valve block VBL to the wheel brakes.

From the working chambers 10a and 10c of the double-stroke piston also run hydraulic lines, are connected to the check valves S1 and S2, to the reservoir VB.

A travel simulator WS with piston, check valves RVO, RV1, orifice D and solenoid valves ESV, WA is connected via a hydraulic line with orifice D or check valve RVO with a working chamber of the piston-cylinder unit with auxiliary piston 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. An 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 convert the pedal force into pressure more quickly. The travel simulator WS can expediently be arranged parallel to the THZ or else in the valve block VBL.

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 correspondingly be measured. 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 ( 1 ).

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 2a shown and described below is 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). Here comes the volume for the pressure reduction via return lines R to the 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 4 EV and 4 AV 4, the MUX pressure control with 4 SV can be used. One of the many advantages is precise pressure control, in that the piston (DHK) controls the corresponding volume in the wheel circle. This procedure can also be used here at Pauf via 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 2.

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 1 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 2 ,

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 reaching the path simulator (WS) -Ansteuerpunkts about 40% of the pedal travel the valve TVDK closed together with the WA valve of the path simulator WS, which already in the stage 2 the path simulator WS is closed. Ie. in stage 1 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 the 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 of the applicant, to which reference is hereby made, when 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.

2 is different too 1 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 2 this valve is drawn for the function VF and is in contrast to 1 between the valve AS and the double-stroke piston 15 positioned.

This double piston DHK2 or DHK3 gem. 1 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 1 and 2 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 1 with three pistons for double-stroke piston (DHK2) according to 2 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 the function has to be maintained for single errors.

2a 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 3 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 centrally arranged centrally arranged axis, in the region of the first piston-cylinder unit (Doppelhubkolben) is 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 1 and 2 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 1 and 2 be shown 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

D

Aperture for throttling

S1

Suction valve 1

S2

Suction valve 2

R

Return to the VB

RV0

Check valve 0

RV1

Check valve 1

WS

travel simulator

OSR

Pressure relief valve

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

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]
• DE 102011111369 [0004, 0005]
• DE 102012222897 A1 [0005, 0043]
• DE 102013111974 [0006, 0012, 0013, 0022, 0028, 0029, 0029, 0031, 0039]
• DE 102014102536 [0012, 0013, 0022, 0031, 0031, 0037, 0037, 0041]
• DE 102010045617 [0023, 0031, 0031]
• DE 102005055751 [0027]
• DE 102012103506 [0028]
• DE 102012205962 [0031]
• DE 102011050587 [0041]
• DE 102008051316 [0045]

Claims (13)

Actuation system for a vehicle brake, with an actuating device, in particular a brake pedal, at least one (first) piston-cylinder unit which is connected via a hydraulic line with at least one brake circuit to supply the brake circuit pressure means and to pressurize the vehicle brake, and a Drive for the piston-cylinder unit, characterized in that by means of at least one, in particular stepped executed, piston (DHK) of the piston-cylinder unit ( 10 . 10a . 10b ) controlled at least one brake circuit in both piston-movement directions, in particular during the forward and return stroke, pressure medium can be fed. Actuating device according to claim 1, characterized in that the (first) piston-cylinder unit ( 10 . 10a . 10b ) two or three pressure chambers ( 10a . 10b . 10c ). Actuating device according to claim 1 or 2, characterized in that between a pressure chamber ( 10b ) of the double-stroke piston ( 10 ) and one from the back of the piston ( 12a ) another (second) 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 a piston of the piston-cylinder unit, is arranged. Actuating device according to one of the preceding claims, characterized in that a further (third) piston-cylinder unit (auxiliary piston unit) ( 16 ) is connected via a hydraulic line to a travel simulator (WS). Actuating device according to claim 4, characterized in that the further (third) piston-cylinder unit ( 16 ), which is in particular an auxiliary piston unit, has a force-displacement simulator (KWS). Actuating device according to claim 4 or 5, characterized in that a pressure chamber of the further (third) piston-cylinder unit (auxiliary piston unit) ( 16 ) is connected via a hydraulic connecting line and at least one solenoid valve (EADK) with at least one brake circuit. Actuating device according to one of the preceding claims, characterized in that for the pre-filling of a pressure chamber of the piston of the (first) piston-cylinder unit (Doppelhubkolben DHK3 or DHK2) between this pressure chamber and at least one of the brake circuits, a hydraulic connecting line with a solenoid valve (VF ) is provided. Actuating device according to one of the preceding claims, wherein the drive comprises an electric motor, characterized in that the electric motor ( 8th ) is arranged parallel to the piston-cylinder unit driven by it and the drive takes place in particular via a toothed belt or the like. Actuating device according to one of the preceding claims, characterized in that the hydraulic systems and lines or pressure chambers at vehicle standstill, in particular in the idle state of the vehicle, by open valves to the return line (R) in a surge tank (VB) are pressure balanced. Actuating device according to one of the preceding claims, characterized in that by means of the (first) piston-cylinder unit ( 10 . 10a . 10b ), in particular by designing the seals and / or valve circuit, a negative pressure can be generated, in particular for setting a Belaglüftspiels. Method for operating a braking device, in particular according to one of the preceding claims, characterized in that the delivery volume from the effective piston surface and the piston stroke of the Doppelhubkolbens DHK is used for pressure-related correlation with the pressure-volume curve of the individual wheel brakes or the entire system for the diagnosis of Leaks in the brake circuits BK and possibly their shutdown or if air is present in the brake circuits BK. Method for operating a brake device, in particular according to one of the preceding claims, characterized in that a defined delivery volume of the Doppelhubkolbens DHK, in particular oriented on the pressure-volume characteristic of the respective wheel, for pressure build-up or pressure reduction via a respective inlet valve or outlet valve for control the double-stroke piston DHK is used. Method according to one of claims 10 to 12, characterized in that by means of the (first) piston-cylinder unit ( 10 . 10a . 10b ) A negative pressure is generated, in particular for setting a Belaglüftspiels.

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