DE102004005107A1 - Braking force generator for a motor vehicle's hydraulic braking facility has a force input, a main brake cylinder, a simulating device for pedal counter force and a device to detect pedal operation - Google Patents

Abstract

Secured in a braking force generator's (10) base casing, a force input link couples to a brake pedal (P). A pedal operation is detected by a swing angle sensor (SWS) (150) and transmitted to an SWS evaluatory device (152) that transmits a signal to an electronic control unit (ECU) (154) so as to match a current pedal operation. This signal helps the ECU to control a vacuum pump (156) etc. An independent claim is also included for a braking system for a motor vehicle.

Description

The The present invention relates to a braking force generator having a Force input member which can be coupled or coupled with a brake pedal and in a base housing of the braking force generator is displaceable, a master cylinder, in which a primary piston displaced led is, being the primary piston with the master cylinder, a primary pressure chamber for generating a hydraulic brake pressure limited, one with the force input element coupleable counterforce force simulation device, a pedal operation detecting means for detecting a pedal operation and an operation force generating means for generating one on the primary piston acting actuating force.

In today's conventional brake systems necessary for applying the wheel brake on the vehicle hydraulic brake pressure is generated mainly by means of a master cylinder. For this purpose, the initiation of an actuating force on the said master cylinder is necessary, which is generated in response to actuation of the brake pedal by the driver. To improve the operating comfort usually the actual brake pedal force is raised by a brake booster by a predetermined percentage, so that the necessary brake pedal operating forces for a desired vehicle deceleration can be kept so small that it is possible for each driver without effort to decelerate the vehicle adequately. Such a brake system with brake booster is for example from the DE 44 05 092 known.

adversely affects in these braking systems that the driver through his activated action on the brake pedal in any case the hydraulic pressure at the wheel brakes affected. As long as this supports the braking situation is this is not a problem. Once the driver but based on the actual Brake situation reacts incorrectly, for example, by too much or too little brake pressure einsteuert, the braking behavior, in particular the braking distance as well as the directional stability of the vehicle are deteriorated, which in the worst case can lead to an accident.

modern Vehicle control systems (ABS, ESP, TC, etc.) are nowadays in the Location the optimal, necessary braking performance in the physical limits based on the current driving condition of the vehicle to determine and thus to optimize a braking. Basis for this, however, is that the above said direct influence of the driver on the brake pressure prevented becomes. Furthermore, it is now also considered uncomfortable that the driver on the brake pedal the effect of the vehicle control system feels such as when activating the ABS a repeated shaking on Brake pedal.

In order to take into account these requirements associated with vehicle control systems, in modern brake systems, the brake pedal is already decoupled from the braking force generation, in which case the brake pedal actuation only serves to determine the driver's desired deceleration. The actual braking force generation, for example for actuation of the master brake cylinder, then takes place by a separate braking force generator and indeed only based on control data of an electronic control unit. In this way, it can be checked in advance whether, for example, the desired vehicle deceleration would not exceed the, currently valid physical limits with respect to braking distance and directional stability determined by the vehicle control systems (ABS, ESP, TC, etc.). At the same time, of course, a delay that has been set too low by the driver to minimize the stopping distance in emergency situations can be compensated by the control unit by controlling a higher brake pressure. Such a system is, for example, in the generic state of the art according to the EP 1 070 006 described. However, it has been shown that such brake systems are relatively expensive to manufacture and require a considerable technical equipment effort to ensure reliable braking operation even if the means for braking power generation should fail once.

It is in contrast An object of the present invention is a braking force generator to provide the type described, which is relatively simple and cost-effective construction a high reliability has and also in case of failure of individual components a reliable braking effect guaranteed.

This object is achieved by a braking force generator having the features described in the introduction, wherein it is further provided that the actuating force generating means comprises a control valve, a chamber assembly and an electromagnetic actuator, wherein the chamber assembly with a vacuum chamber and one of the vacuum chamber by a movable Is formed wall separated and fluidically connectable to each other via the control valve working chamber and wherein the control valve in accordance with the detected pedal operation by the electromagnetic actuator to achieve an actuating force determining pressure difference between the Ar beitskammer and the vacuum chamber is controlled.

Accordingly, with the braking force generator according to the present invention, in a normal operation situation, the intensity of the brake pedal operation given by the driver of the vehicle via the force input member is detected, and an operation force is applied to the primary piston without utilizing the pedal operation force applied to the brake pedal by the driver alone by the operation force generating means , Similar to the above-mentioned prior art according to the EP 1 070 006 According to the invention, the actuating force exerted on the primary piston is mechanically decoupled in the normal operating mode from the pedal actuating force exerted on the force input element. However, the operating force generating device used for this purpose in the context of the invention is not designed as a separate hydraulic system, which would lead to a considerable additional technical effort and in addition to the associated additional costs to an increased susceptibility to errors. Rather, the braking force generator according to the invention is realized by means of a chamber arrangement, as it comes in conventional pneumatic brake booster for mechanical support of Pedalbetätigungskraft used. The Applicant has recognized that the technically mature and cost-effective available principle of a pneumatic brake booster can also be used to a fully decoupled from the pedal actuation actuating force generation. For this purpose, in accordance with the intensity of the brake pedal actuation, the chamber arrangement is actuated via the control valve to thereby set a pressure difference between the vacuum chamber and the working chamber to produce an actuating force acting on the primary piston in accordance with the expressed with the pedal actuation driver request. As a result, this pressure difference leads to a displacement of the movable wall and, as a result, to a displacement of the primary piston.

Around monitor the operation of the brake force generator according to the invention to be able to and by a parameter for feedback the response of the braking force generator according to the invention in To be able to provide the framework of a control loop, sees a development the invention that the current position of the movable Wall is detected by means of a position sensor. It can the Position sensor be formed inductively or mechanically. A simple, inexpensive and yet reliable Embodiment results, for example, when the position sensor is formed with a stylus, which is biased on the movable wall and their position during a displacement can capture.

Regarding the pedal operation detecting means can be provided that this sensor for detecting a current deflection of the brake pedal, in particular one on a rotation axis having the brake pedal arranged angle of rotation sensor. But it is equally possible, the pedal operation detect by means of a differently shaped sensor, for example based on the translational movement of the force input element or by means of a pressure load occurring within the force input element.

As already from conventional pneumatic brake boosters known, can be provided in the braking force generator according to the invention be that the vacuum chamber to generate a negative pressure with the intake tract of an internal combustion engine or with a vacuum pump is fluidically connected.

As already stated above, is unlike traditional ones Brake boosters the pedal actuation force in the inventive solution in Normal braking case, that is at full functionality of the brake system, not forwarded to the primary piston. Much more it is necessary, by means of the electromagnetic actuator a operating force to create. Thus, the actuator in the form of a linear drive or be carried out a rotary drive whose Ratationsbewegung over a Gear assembly, such as a ball screw, in a translational movement is converted. A preferred embodiment The invention provides that the electromagnetic actuator a on the control valve housing fixed coil and by means of the coil relative to this having displaceable magnetic armature. With this embodiment let yourself a cost effective, reliable and low friction operating and exactly positionable braking force generator achieve.

A central component of the braking force generator according to the invention is the control valve. According to the invention, this can be designed such that it has a control valve housing which can be displaced relative to the base housing and a control valve element which can be displaced relative to the control valve housing, wherein the housing valve seat can be brought into sealing engagement with the control valve element is provided, further with the electromagnetic actuator, in particular with its armature, a control valve sleeve is coupled, on which a sealable in sealing contact with the control valve member sleeve sealing seat is provided. In operation may be provided in such an arrangement that at close concern of control valve element and sleeve sealing seat and simultaneously separated control valve element and housing sealing seat Arbeitskam mer with the vacuum chamber is fluidly connected and that in dense concerns of control valve element and housing sealing seat and at the same time separated control valve element and sleeve sealing seat to build a differential pressure between the working chamber and the vacuum chamber, the working chamber is separated from the vacuum chamber and fluidly connected to the ambient atmosphere. With such a design of the control valve, one initially starts from the conventional design of a control valve used in the context of pneumatic brake boosters and adapts its mode of operation to the solution according to the invention. In particular, the control valve sleeve and thus the sleeve sealing seat is not lifted about the force input element, but via the electromagnetic actuator of the control valve element and thus created the condition for the construction of a pressure difference between the vacuum chamber and the working chamber. As a result, an overpressure with respect to the vacuum chamber forms in the working chamber, which leads to a displacement of the movable wall in the chamber arrangement and with this to a displacement of the control valve housing. Finally, the sleeve sealing seat comes again into contact with the control valve element, so that an equilibrium state is established, in which the current actuation force is maintained. In a further displacement of the electromagnetic actuator, in particular of the armature, there is a corresponding adjustment of the pressure difference and thus after a displacement of the control valve housing to a corresponding adjustment of the force acting on the primary piston actuating force. If the driver reduces the pedal actuation until finally releasing the brake pedal completely, the electromagnetic actuator reacts accordingly by moving the armature back to the initial position, which ultimately results in the housing sealing seat being lifted off the control valve element. This can be done a new pressure equalization between the working chamber and the vacuum chamber until finally there is almost equal pressure. In this case, the control valve housing also moves back to its initial position, so that the actuation force is finally reduced back to zero.

Around ensure that in normal operation, that is at full operability all components of the system no mechanical coupling between the force input element or a component connected thereto takes place and still for In case one of the components fails, an emergency operation mode guarantee can, in which the driver of the vehicle this still slow down can, are in one embodiment the invention made the following precautions. Especially provides this embodiment, that between the force input member and one the control valve actuated Component, in particular the anchor, a safety clearance is provided, despite the relocation of the anchor by the coil despite activity overcome the brake pedal is, so that the control valve actuated component, in particular the armature, with the force input element is force-transmitting coupled, wherein one by a brake pedal operation induced further displacement of the force input element immediately on the control valve actuated Component, in particular the anchor, and subsequently transmitted to the control valve housing becomes. The safety clearance is such that, in normal operation, this means then, when the electromagnetic actuator in response to a detected pedal operation in provided, never be overcome and thus the Force input element or a component connected to this also not in mechanical contact with the anchor or a component of the Control valve housing arrives.

In an operating situation in which the electrical control of the electromagnetic actuator does not work correctly, for example because the pedal operation detecting means has failed, remains the electromagnetic actuator, in particular the anchor, despite a push the brake pedal by the driver in its starting position. In approaching the episode the force input element or the component connected to it the armature more and more without it comes to a braking effect. Upon further depressing the brake pedal is finally the Security game used up. The force input element or the with This coupled component comes in mechanical and power transmitting Contact with the electromagnetic actuator, in particular with the Anchor, and relocates it. As a result, the valve sleeve is displaced, so that the sleeve sealing seat lifts off the control valve element. However, this leads - as already stated above - to a Structure of a pressure difference between the vacuum chamber and the Working chamber, resulting in the generation of an actuating force. Of the brake force generator according to the invention works accordingly with not properly functioning electromagnetic Actuator after overcoming the Safety game like a conventional one Brake booster.

Even in an operating situation in which the vacuum source, for example, a separately formed vacuum pump fails, with the brake force generator according to the invention still a sufficiently large braking force can be generated for braking the vehicle. In this case, the chamber arrangement remains ineffective. However, the arrangement according to the invention is designed such that the force input element after overcoming another safety game finally mechanically comes into contact with the primary cylinder, so that the force exerted on the force input member Pedalbetätigungskraft after overcoming the safety games can be transferred directly to the primary piston, thus initiating a braking. Then, the force exerted by the driver on the force input member operating force can be transmitted directly to the primary cylinder.

As already stated, there is a fundamental idea the invention therein, in normal operation at full functionality all Components of the brake system, with each braking on the primary piston acting actuating force decoupled from a pedal actuation force to create. In order to compact design of the braking force generator according to the invention also relatively high Generate actuating forces to be able to provides a development of the invention, that the chamber arrangement as a tandem chamber arrangement with a first chamber arrangement and one formed by this separate second chamber assembly is, wherein the first chamber arrangement, a first vacuum chamber and a first one separated therefrom by a first movable wall Working chamber has. The second chamber arrangement has a second vacuum chamber and one of these by a second movable wall separate second working chamber. Further, the first and second Chamber arrangement over the Control valve pressurized. In this context can Also provided according to the invention be that the first movable wall and the second movable wall for the purpose of common movement with each other, preferably rigid, coupled.

It was in the context of the present invention description multiple times mentioned, that the force input element is not directly mechanically with the Operating force generating means is coupled. Nevertheless, to give the driver the accustomed impression that the brake system an actuation the brake pedal opposes a mechanical resistance sees the invention a per se known counter-pedal force simulation device in front. Such a pedal counterforce simulation device may, for example close be arranged to the force input element. However, this leads In general, a considerable increase in the size of the arrangement, which is the Demand for compactness precludes. The invention provides Avoiding such space enlargements before that the pedal counter-force simulation device space-saving integrated in the brake force generator according to the invention is. A measure for realizing such an integrated solution is according to the invention, for example in that the force input member is via a transmission piston assembly is coupled to the pedal counter force simulation device. Furthermore may be provided in this context that the counterforce force simulation device via a Pedal counter-force hydraulic system with a damper assembly force-transmitting can be coupled. So lets the effect of pedal counterforce simulation device is transmitted, so that their components at almost any point of the braking force generator can be positioned So also there, where space is available.

Around the driver one of conventional braking systems convey known resistance behavior during the operation of the brake pedal to be able to provides a development of the invention that the damper assembly one over a displaceable by the pedal counter-force hydraulic system power piston compressible simulation spring and / or fluidic damping means, preferably a throttle, and / or a rubber-elastic stop disc having. While with the simulation spring and the rubber-elastic stop disc a progressive force change with increasing pedaling reach, serve the fluidic damping means especially for the cause a hysteresis, which is a delayed return movement of the brake pedal after its release entails. Furthermore have the fluidic damping means the effect that they are at a sufficiently rapid actuation of the Brake pedal to the driver a known from conventional braking systems feeling of resistance convey, in each operating situation of the brake system according to the invention.

As already stated above, the braking force generator according to the invention is designed so that it ensures a reliable braking effect even after a failure of individual components. In particular, when it is necessary to make the best possible use of the pedal operating force exerted by the driver on the brake pedal to generate an operating force in an emergency operating situation, it is necessary to avoid dissipating a part of the pedal operating force due to the action of the pedal counter force simulating means. A further development of the invention therefore provides for the pedal counterforce simulation device to be switched on or off as required. In particular, an embodiment of the invention in this context provides that the hydraulic system of the pedal counter-force simulation device is formed with a controllable isolation valve, which in a first position, preferably in its passive position, the damper assembly and the transmission piston assembly hydraulically decoupled from each other and a substantially undamped movement the transmission piston assembly allows and that in ei ner second position, preferably in its active position, the damper assembly and the transmission piston assembly hydraulically coupled together. With regard to the control of the isolation valve can be inventively provided that the isolation valve is switched at the beginning of a brake pedal actuation from its passive position to its active position and is switched again from its active position to its passive position after completion of the brake pedal operation. In addition, the isolation valve can already be exploited to achieve a throttle effect by being provided with a throttle element, preferably with a spring-biased orifice, which throttles in the active position of the isolation valve, a hydraulic fluid flow to the damper assembly. As a result, the hysteresis effect and the damping effect of the damper arrangement can be further enhanced. Preferably, the orifice plate is arranged so that it, even if the isolation valve is switched to its passive position, throttles a fluid flow in the hydraulic system, so that the driver, for example, in an emergency operating situation in which the damper assembly is not coupled to the brake pedal, at a Pressing the brake pedal feels a resistance.

Regarding the embodiment of the master cylinder provides a development the invention that this in a cylinder housing, preferably as a cylinder bore open on one side, is formed. Preferably is the isolation valve, as well as the damper assembly integrated in the cylinder housing or attached as a separate assembly to this. The braking force generator according to the invention can also be made even more compact that the damper assembly in the cylinder housing integrated or attached as a separate assembly to this. Thus, the actually space-demanding unit of the pedal counter-force simulation device, namely the damper arrangement, be placed at a place where space is available, and does not have to be positioned near the pedal.

To For ease of assembly and a compact design provides a development of the invention, the cylinder housing together with the components arranged therein as an assembly in the base housing insertable and with this solvable connected is.

Further can increase the reliability the braking system according to the invention further be provided that in the master cylinder, a secondary piston displaced led is that the secondary piston with the master cylinder, a secondary pressure chamber for generating a hydraulic brake pressure includes, and that the primary piston with the master cylinder and the secondary piston to produce a hydraulic brake pressure includes the primary pressure chamber. In this Context can about it be provided that the primary piston and optionally the secondary piston by means of these associated biasing springs in each case in a starting position are biased.

above was already on the individual components of the counterforce force simulation device received. With regard to their arrangement provides a development the invention that the primary piston is provided with a through hole in which an actuating piston guided is, wherein the actuating piston an actuating cylinder bore in which a separating piston by means of the transmission piston assembly displaced led wherein the separating piston in the actuating piston is a hydraulic fluid chamber fluidly connected to the hydraulic system of the pedal counter-force simulation device is coupled. To provide permanent contact between the transfer piston assembly and ensure the separating piston and thus a reliable coupling of the force input member with the pedal reaction force simulation device guarantee to be able to provides a development of the invention that a the separating piston contacting component of the transfer piston assembly Magnetically and / or adhesively with the separating piston and / or by latching solvable is coupled. About that In addition, the invention can be provided be that the actuating piston in the cylinder housing is fixed.

The Invention also provides an electronic control device, which monitors the pedal operation detecting means, and the electromagnetic actuator in accordance with an output signal the pedal operation detecting means, preferably considering a predetermined characteristic or a predetermined characteristic field, controls. From the characteristic field, depending on prevailing operating parameters individual characteristic curves selected and the control of the braking force generator are based. Depending on the design of the brake system can continue according to the invention be provided that the characteristic or the characteristic field fixed predetermined or adaptable to detected operating parameters. So it is also possible on driver's request or in adaptation to the determined driver behavior to select different characteristics determining the behavior of the brake or to create.

A development of the invention in this context provides that the electronic control device actuates the electromagnetic actuator in accordance with a hydraulic pressure detected in the hydraulic system of the pedal counter-force simulation device, for example on the separating valve. Furthermore, with regard to the activation of the braking force generator according to the invention, it can be provided that the electronic control device actuates the electromagnetic actuator in accordance with a parameter determined by a vehicle control system, such as the distance to a preceding vehicle, the current hydraulic pressure in the brake system, the current vehicle deceleration or the like. Moreover, it is possible according to the invention for the electronic control device to actuate the electromagnetic actuator in accordance with a change over time of the output signal of the pedal actuation detection device or / and of the hydraulic pressure detected in the hydraulic system of the pedal counterforce simulation device, for example on the isolation valve. As stated above, in certain operating situations, it is necessary to deactivate the pedal drag simulation device. For this purpose, it can be provided that the electronic control device controls the isolation valve in accordance with an output signal of the pedal operation detection device.

Further can be provided that the electronic control device at the control of the electromagnetic actuator, an output signal of the Position sensor considered. This can be achieved that the current position of the movable Wall, or in the case of a tandem arrangement of both movable walls, as Feedback information be used to correct the actuator as part of a To control the control loop again.

The Invention will be explained below with reference to the accompanying figures. It represent:

1 a schematic overview of the brake force generator according to the invention and the coupled with this vehicle components;

2 an enlarged side view of the braking force generator;

3 a longitudinal sectional view of the brake force generator according to the invention in the unactuated position;

4 a view accordingly 3 but in a partially-engaged position;

5 a detailed view of a first embodiment of a damper assembly of a counter-pedal force simulation device;

6 a view accordingly 5 a second embodiment of the damper assembly of the pedal counter-force simulation device;

7 a sectional view taken along the section line VII-VII from 2 and

8th a second embodiment of the braking force generator according to the invention.

In 2 an inventive braking force generator is shown in side view and generally with 10 designated. This comprises an actuating unit 12 into which a force input element 14 is introduced. The force input element 14 is at its free end with a in 2 not shown brake pedal coupled. The operating unit 12 is to a chamber arrangement 16 connected. At the of the operating unit 12 opposite side of the chamber arrangement 16 is a part of a cylinder housing 18 the master cylinder recognizable.

For a detailed description of the structure of the brake force generator according to the invention 10 should be listed below 3 Be referred. The braking force generator according to the invention 10 consists in its basic structure of two modules, namely on the one hand, the cylinder housing 18 and on the other hand, the Bremskrafterzeugergehäuse 20 , in which the cylinder housing 18 used and with which it is detachably connected. In the in 3 right part of the braking force generator 10 , in particular of the housing 20 , opens the rod-shaped force input member 14 , In this area is a control valve 22 intended. The control valve 22 includes a control valve housing 24 that is relative to the housing 20 is relocatable. Inside the control valve housing 24 is a relative to this movable valve sleeve 26 intended.

The control valve housing 24 is fixed to one in the chamber arrangement 16 arranged first movable wall 28 coupled. The first moving wall 28 under divides the in 3 right part of the chamber arrangement 16 in a vacuum chamber 30 and a working chamber 32 , The vacuum chamber 30 is about one in the case 20 fixed rigid wall 34 from the in 3 left part of the chamber arrangement 16 separated. Also this part of the chamber arrangement 16 includes a vacuum chamber 36 and a working chamber 38 passing through a second moving wall 40 are separated from each other. The first moving wall 28 and the second moving wall 40 are rigidly coupled together for the purpose of joint movement. This is the second movable wall 40 on a coupling sleeve 42 attached via a connection socket 44 fixed to the control valve body 24 connected is.

In the control valve housing 24 is an electrically controllable coil 46 an electromagnetic Actuator 48 arranged. The actuator 48 further includes a relative to the control valve housing 24 as well as to the coil in the direction of the longitudinal axis A of the braking force generator 10 movable magnetic anchor 50 , The anchor 50 is for a common movement in the axial direction with the valve sleeve 26 coupled. In addition, the anchor 50 provided with an axial through hole through which a transmission piston 52 slidably extends. The anchor 50 is about a spring 54 in the in 3 biased shown position. At his in 3 right end is the transmission piston 52 via a coupling element 56 with the force input element 14 connected force-transmitting. Between the anchor 50 and the coupling element 56 is in the in 3 shown rest state of the braking force generator 10 a safety game s provided.

The valve sleeve 26 , the control valve housing 24 and a valve element which is displaceable relative thereto 58 form the actual control valve 22 , In the in 3 shown state is the valve sleeve 26 with her the valve element 58 facing sleeve seat 60 on the valve element 58 at. Further, in this state, an on the control valve housing 24 trained housing sealing seat 62 from the valve element 58 lifted. In the in 3 shown state connects the control valve 22 each the vacuum chamber 30 with the working chamber 32 and the vacuum chamber 36 with the working chamber 38 , The vacuum chambers 30 and 36 are coupled to a vacuum source, not shown, for example, with the intake of an internal combustion engine with the braking force generator 10 equipped vehicle or with a separate trained vacuum pump. The force input member is via a return spring 63 in the in 3 biased shown position.

The transmission piston 52 extends with his in 3 left end in a primary piston 64 in, which is designed with an axial through hole. The primary piston 64 is sealing in a hole open on one side 66 guided in the cylinder housing 18 is trained. In the through hole of the primary piston 64 is an actuating piston 68 displaced led. Also the actuating piston 68 has a one-sided open hole 70 on that with one in this displaceable separating piston 72 is closed. The separating piston 72 closes with the actuating piston 68 a hydraulic chamber 74 one. The actuating piston 68 lies over a stop pin 75 that by one in the primary piston 64 provided slot hole 73 passed through, at a diameter stage in the interior of a fixed to the cylinder housing 18 coupled closure sleeve 78 at. He is characterized by an axial movement in 3 hindered to the right.

The hydraulic chamber 74 is via a connection channel 76 with the interior of the closure sleeve 78 connected and communicates via this interior with a in the cylinder housing 18 trained fluid channel 80 , The fluid channel 80 leads to the in 7 closer in a sectional view shown electromagnetic isolation valve 82 , This includes an electromagnetically controllable coil 84 and one in the coil 84 movably guided anchor 86 , The anchor 86 is via a return spring 88 in the in 7 biased shown position. The anchor 86 has an extension 90 , with the free end he has a spherical valve element 92 against a valve seat 94 can press. The valve seat 94 connects a fluid chamber 96 via one with the valve element 92 Sealable through-hole with an antechamber 98 , The fluid chamber 96 is via a connection channel 100 with a hydraulic fluid reservoir 102 fluidly connected. The antechamber 98 is via a connection channel 104 with a pedal counter force simulation device 106 fluidly connected.

In the antechamber 98 is an orifice 99 via a biasing spring 101 to the valve element 92 biased towards. The orifice 99 has a throttle bore 103 on. Furthermore, in the antechamber 98 a mounting element facilitating the assembly 105 arranged.

The pedal backlash simulator 106 is in 5 in a first embodiment in which it fits into the cylinder housing 18 is integrated, enlarged and shown in section. The connection channel 104 opens into a hydraulic chamber 108 , which by means of a simulation piston 110 is delimited. The simulation piston 110 is along a longitudinal axis B within the cylinder housing 18 displaced. He has an investment flange 112 on, at one end of a simulation spring 114 is applied. Furthermore, the simulation piston points 110 one in the simulation pen 114 protruding rounded extension 116 on. The simulation spring 114 is in a spring chamber 118 arranged by means of a fastening ring 122 secured plugs 120 closed is. The sealing plug 120 has a central opening 128 on. In addition, the spring chamber 118 via a lateral bore 126 connected to the atmosphere. In the stopper 120 is a rubber-elastic stop disc 124 arranged in the case of sufficiently further displacement along the axis B of the extension 116 of the simulation piston 110 can dive elastically.

Turning to the construction of the braking force generator according to the invention, as in 3 is shown, it can be seen in this representation that in the cylinder housing 18 next to the primary piston 64 also a secondary piston 130 slidably received. The primary piston 64 limited together with the boundary wall of the hole 66 and the secondary piston 130 as well as in 3 left end of the actuating piston 68 a primary pressure chamber 132 , The secondary piston 130 limited together with the boundary wall of the hole 66 a secondary pressure chamber 134 , Primary piston and secondary piston are via return springs 136 and 138 in the in 3 biased position shown.

Finally, in 3 another position sensor 140 shown. The position sensor 140 has an in 3 to the right spring-loaded ram 142 on, with its free end always on the movable wall 40 is present and their current position recorded.

Regarding the assembly of in 3 shown braking force generator 10 It should be noted that this itself consists of two basic modules. The first base assembly includes the housing 20 and all components arranged therein, in particular the components of the chamber arrangement 16 and the control valve 22 , The second base assembly includes the cylinder housing 18 and all attached components, in particular the pedal backlash simulator 108 , the isolation valve 82 , as well as the primary piston 64 and the secondary piston 130 , These two basic modules are preassembled and connectable in the preassembled state, the cylinder housing 18 in the case 20 can be introduced sealingly. The interface of these two components then form the mutually contacting contact surfaces of primary piston 64 and connection socket 44 as well as transmission pistons 52 and separating piston 72 , In particular, the interface between transfer pistons 52 and separating piston 72 is play-free train to give the driver an immediate response of the brake system to a pedal operation. Therefore, the separating piston 72 magnetically formed so that it transmits the ferromagnetic transmission piston 52 inevitably contacted during assembly and remains in contact with this. If desired, the bore 70 be provided at its open end with a subsequently attached stop, for example, a locking ring or a flange, so that an unintentional sliding out of the separating piston 72 is prevented.

Before on the actual operation of the brake force generator according to the invention 10 is to be involved in its integration into a vehicle braking system, taking into account 1 be explained in more detail. There is schematized the braking force generator according to the invention 10 shown with a brake pedal P. A pedal operation is via a rotation angle sensor 150 detected and to a rotation angle sensor evaluation 152 transmitted. This transmitted to an electronic control unit 154 a signal corresponding to the current pedal operation. In accordance with the signal characterizing the current pedal operation, the electronic control unit controls 154 a vacuum pump 156 as well as other components of the braking force generator 10 as will be explained below. In addition, the electronic control unit controls 154 a brake light 158 in response to a detected pedal operation. The electronic control unit 154 also receives signals from various control systems within the vehicle, such as an electronic stability program 160 , an antilock braking system 162 , an automatic cruise control system 164 or similar. Those of these programs to the electronic control unit 154 flowing signals are evaluated and used to control the braking force generator according to the invention.

The following is intended with reference to 3 and 4 the operation of the braking force generator according to the invention will be discussed.

4 shows the braking force generator according to the invention 10 in partially actuated position with normal functioning. As a result of an actuation of the brake pedal, the force input element 14 subjected to the force F and opposite to the in 3 shown starting position shifted by the distance Δp along the longitudinal axis A of the braking force generator. The brake pedal operation is directly from the in 1 shown angle of rotation sensor 150 recorded and sent to the electronic control unit 154 forwarded. This controls the coil 46 These are energized and energized in accordance with predetermined characteristics and possibly taking into account further parameters, for example from the stability program 160 , the antilock braking system 162 or the distance control device 164 , By energizing the coil 46 builds up in this a magnetic field, which is the anchor 50 in 4 pull it to the left into the coil. This is the valve sleeve 26 from the anchor 50 taken. The valve element 58 moves with the valve sleeve 26 with, until it is on the housing sealing seat 62 comes to the plant. Then the sleeve sealing seat lifts 60 from the valve element 58 from. As a result, the first vacuum chamber 30 from the first working chamber 32 and the second vacuum chamber 36 from the second working chamber 38 isolated as well as the working chambers 32 and 38 connected to the ambient atmosphere. It builds a pressure in the working chambers 32 and 38 which leads to a displacement of the control valve housing 24 against a force of a return spring 166 leads and thus also to a shift of the primary piston 64 and the secondary piston 130 , This builds up in the primary pressure chamber 132 and in the secondary chamber 134 one brake pressure each on, in one on the braking force generator 10 connected vehicle brake system is used to decelerate the vehicle. The two movable walls 28 and 40 move together with the control valve body 24 until, until both sealing seats, namely the sleeve sealing seat 60 and the housing sealing seat 62 , again in contact with the valve element 58 are located. In this condition, the system is in equilibrium and no further change occurs without external influence.

As stated above, the actuation of the control valve takes place 22 by a displacement of the anchor 50 that's over in the coil 46 generated magnetic force along the longitudinal axis A is moved. The movement of the force input member 14 and the force F initiating this is, however, in the in 4 not shown on the armature 50 transfer. Rather, this movement of the force input element 14 over the coupling element 56 on the transmission piston 52 transfer. The transmission piston 52 is subsequently within the primary cylinder 64 , in particular within the unilaterally open bore 70 of the actuating piston 68 displaces and shifts the separating piston 72 in 4 to the left, with the actuating piston 68 because of in the primary pressure chamber 132 prevailing hydraulic pressure relative to the housing 18 remains in his position. By the movement of the separating piston 72 becomes hydraulic fluid from the hydraulic chamber 74 over the connection channel 76 and the fluid channel 80 to the electromagnetic isolation valve 82 promoted. The electromagnetic isolation valve 82 is due to the detected pedal operation of the electronic control unit 154 switched to its active position in which it is the valve element 92 to the valve seat 94 suppressed. This can do this to the isolation valve 82 delivered hydraulic fluid not in the hydraulic fluid reservoir 102 but against the resistance of the pedal backlash simulation device 106 in the hydraulic chamber 108 promoted. This is the simulation piston 110 under compression of the simulation spring 114 in the spring chamber 118 moved into it. Depending on the speed of the displacement of the simulation piston 110 there is a fluidic damping due to a throttle effect of the orifice 99 passing hydraulic fluid through its orifice and bore 126 when exiting the spring chamber 118 contained air. Finally, there is sufficient further deflection of the extension 116 , to a strong damped movement of the simulation piston 110 as soon as the extension 116 with the rubber-elastic stop disc 124 contacts and compresses them.

If the brake pedal is released by the driver, the system moves from the in 4 shown position in the 3 shown position back. The force input element 14 is due to the action of the pedal counter-force simulation device 106 and further return springs moved back to its original position. However, this return movement takes place with hysteresis, as on the one hand through the hole 126 only throttled air into the spring chamber 118 can occur and on the other hand, the orifice 99 a backflow of hydraulic fluid into the hydraulic chamber 74 throttles.

During activation of the actuator 48 detects the electronic control unit 154 permanently via the position sensor 140 the current position of the second movable wall 40 and the first movable wall coupled thereto 28 , As a result, the actual position of the control valve housing 24 be detected and compared with a predetermined by the pedal operation target position. In the event of a deviation from the actual position and the desired position, for example due to a change in the pedal position by the driver or due to other external influences, the electronic control unit controls 154 the actuator 48 corrective. In the case of emergency braking, in which the brake pedal is depressed quickly and with great operating force by the driver, the electronic control unit 154 the actuator 48 also powered disproportionately strong, quickly to a high pressure difference in the chamber arrangement 16 build and order in the episode for the emergency braking sufficiently large braking force with the braking force generator 10 to create.

The above description shows that in normal operation, the force applied to the force input element confirmation force F only a shift of the components coupling element 56 , Transmission piston 52 and due to a hydraulic transmission, a movement of the simulation piston 110 but does not have any immediate effect on the components of the control valve 22 Has. The the primary piston 64 shifting actuation force is rather by activation of the actuator 48 and relocation of the anchor 50 initiated, causing the control valve 22 is actuated to a pressure difference in the chamber assembly 16 to achieve. Due to this pressure difference, the control valve housing moves 24 and with this the primary piston 64 and the secondary piston 130 ,

In the following, emergency operating situations are explained, which show that the braking force generator according to the invention 10 despite a defect in one or more components continues to work:
A first contingency situation to be considered occurs when the coil 46 is no longer properly controlled. This may be due to the fact that the rotation angle sensor 150 is defective or a defect in the electrical system of the vehicle occurs. In such a faulty operating state, the control valve 22 no more about the actuator 48 be operated. Nevertheless, can be with the brake force generator according to the invention 10 achieve a sufficiently good braking effect. When a brake pedal operation, the force input element 14 in 3 shifted to the left. Such a shift remains ineffective until the safety game s is overcome. If this is the case, then the coupling element occurs 56 in mechanical contact with the anchor 50 and move it further in 3 to the left. This will - similar to the above for proper operation with a displacement of the armature 50 described - the valve sleeve 26 shifted until the housing sealing seat 62 in contact with the valve element 58 passes and the sleeve sealing seat 60 from the valve element 58 is lifted. There is a pressure difference in the chamber arrangement 16 which involves a displacement of the control valve housing 24 and finally a displacement of the primary piston 64 pulls. In this first emergency operation situation, therefore, only the safety clearance s must be overcome until a braking effect is achieved by the force exerted on the brake pedal Pedalbetätigungskraft, which is then ultimately generated analogously to a conventional pneumatic brake booster.

It should be noted that in the emergency operation situation described above, in the no proper control of the actuator 48 takes place via the electronic control unit 154 also no transfer of the separating valve 82 from the in 7 shown passive position in an active position. Rather, the isolation valve remains 82 in the in 7 shown passive position, so that caused by the pedal actuation displacement of the force input element 14 no significant drag by the pedal drag simulation device 106 is opposed. This is due to the displacement of the force input element 14 from the hydraulic chamber 74 pressed out hydraulic fluid is pressed substantially without resistance. However works despite closed isolation valve 82 the orifice 99 a hydraulic fluid flow into the reservoir 102 so that the driver feels a resistance on the brake pedal even in the emergency operating situation and especially in a fast brake pedal operation.

In addition to the above-described emergency operation situation in which only the electrical control of the actuator 48 failed and in spite of this defect sufficient braking force generation by the braking force generator according to the invention 10 is ensured, is to consider another emergency operation situation, in addition to or alternatively to a defect in the control of the actuator 48 Also, a defect occurs that affects the operation of the chamber assembly 16 impaired. For example, such a defect could be caused by the fact that the vacuum pump 156 out 1 no longer works properly. This would mean that in the vacuum chambers 30 and 36 No more negative pressure can be generated, so that on the moving walls 28 and 40 Also, no pressure difference can be built more, leading to a braking force generation and ultimately to the displacement of primary piston 64 and secondary pistons 130 can be used.

The braking force generator according to the invention 10 is designed such that it enables a sufficient generation of a braking force even in such an emergency operating situation. Referring to 3 behaves the braking force generator 10 as follows: Upon actuation of the brake pedal is again the force input element 14 moved in the direction of the longitudinal axis A. Despite this shift of the force input link 14 but can be due to the absence of a pressure difference in the chamber arrangement between the vacuum chambers 30 and 36 and the working chambers 32 and 38 with the chamber arrangement 16 do not generate braking force. The position sensor 140 thus captures that the movable wall 40 despite the pedal operation is not moved and reports this immediately to the electronic control unit 154 , Due to this signal, the electronic control unit detects 154 an emergency operation situation and leaves the isolation valve 82 in its passive position, allowing the pedal backlash simulation device 106 remains ineffective. Again, the throttle effect is the orifice 99 but not affected. Also a control of the actuator 48 is not required and stays off.

Due to the movement of the force input element 14 in the axial direction, the safety clearance s is first used up in succession, so that the coupling element 56 in contact with the anchor 50 occurs. In a further movement of the force input member 14 in the axial direction becomes the anchor 50 together with the coupling element 56 from the force input member 14 continue to shift until the anchor 50 finally in contact with the in 3 right area of the connection socket 44 device. Now is the force input element 14 over the coupling element 56 , the anchor 50 and the connection socket 54 force transmitting with the primary cylinder 64 coupled. This allows the primary cylinder 64 upon further movement of the force input member 14 inside the cylinder housing 18 shift so that in the primary pressure chamber 132 and in the secondary pressure chamber 134 builds up a brake pressure with which the vehicle can be decelerated adequately. The braking force generator according to the invention 10 So also offers a possibility for this second emergency operation situation, a sufficiently large brake force to generate, by an immediate transfer of the actuation force generated on the brake pedal to the primary piston 64 allows. In this emergency operating situation, the driver can depress the brake pedal in such a way that its pedal actuating force acts directly on the primary cylinder 64 is transmitted. This is also referred to as a push-through function.

Below is briefly on 6 To be received. 6 shows a second embodiment of the pedal counter-force simulation device. For ease of description and avoidance of repetition, the same reference numerals will be used for like or equivalent components as in the description of FIG 5 used, but with the letter "a" readjusted.

The embodiment according to 6 differs from the embodiment according to 5 only in that the hydraulic chamber 108a , the simulation piston 110a , the simulation pen 114a , the rubber-elastic stop disc 124a and the stopper 120a in a separate housing 168a arranged and designed as a preassembled module, wherein the housing 168a via a threaded connection piece 170a in a corresponding receiving opening 172a of the housing 18a is tightly screwed.

8th shows a further embodiment of the braking force generator according to the invention. To avoid repetition again only the differences from the embodiment according to 3 and 4 for the same or equivalent components, the same reference numerals as previously described in the description of 3 and 4 used, but with the letter "b" readjusted.

The embodiment according to 8th differs from the embodiment according to 3 only in that the stop pin 75b in the locking sleeve 78b through a clamping sleeve 174b is fixed, wherein the clamping sleeve fixed in the larger diameter portion of the stepped inner bore of the closure sleeve 78b is anchored. This allows the stop pin 75b not opposite the case 18b relocate.

The embodiment according to 8th is particularly suitable for the application of the braking force generator according to the invention 10b , in which regenerative braking is required. This means that the braking force generator 10b is used in a vehicle that recovers the energy released during braking at least partially via a generator. Such conditions of use prevail, in particular, in hydride vehicles, in which the vehicle can be driven depending on the operating situation both by means of an electric motor and by means of an internal combustion engine. During braking, the generator generates part of the energy required for electric motor operation, which is stored temporarily in an accumulator. Furthermore, regenerative braking systems can also be used in fuel cell powered vehicles in which electrical power must also be provided for reformation processes or the like.

In such regenerative braking systems, the generator is driven in the event of braking, ie at a brake pedal actuation, at least over the driven wheels. The energy required for this purpose is used to decelerate the vehicle. However, if this delay is insufficient to decelerate the vehicle according to the driver's braking request, it is necessary, as in conventional brake systems, to additionally generate a braking force via the brake system. Substituting the brake force generator according to the invention 10b in such a regenerative braking system, so there is the problem that the braking force generator 10b in a brake pedal operation and a resulting shift of the force input element 14b initially no braking force must be generated. A braking force generated by the braking force generator 10b For example, is not desirable as long as the achievable by the switched generator delay satisfies the predetermined by the driver's desired delay. Only when this condition is no longer met must the braking force generator 10b generate an additional braking force. This means that only then the actuator 48b activated and subsequently the control valve 22b as above with reference to 3 and the following must be addressed when a pure generator braking is no longer sufficient. Before such a control of the control valve and a resulting braking force generation takes place, a shift of the force input element 14b only via the coupling element 56b , the transmission piston 52b and the separating piston 72b transmitted to the pedal counter-force simulation device, which opposes the pedal actuation usual for the driver resistance. Because initially no displacement of the anchor 50b inside the coil 46b should take place, the coupling element 56b However, due to the movement of the force input element 14b in 8th Moved to the left, the safety clearance s is sufficiently large to accommodate an undesired mechanical coupling of coupling element 56b and anchor 50b excluded.

The clamping sleeve 174b is necessary because otherwise the actuating piston 68b under the action of the coupling element 56b , the transmission piston 52b and the separating piston 72b within the primary piston 64b into the primary pressure chamber 132b could shift into it and thus in this phase of braking undesirable brake pressure in the primary pressure chamber 132b could produce.

After the pure generator braking then a smooth transition must be made in a state in which both by means of the generator and by means of the braking force generator 10b braking force generated is braked. In order to make this transition as smooth as possible, the inventive braking force generator can 10b be moved to a standby position in which all empty paths of the arrangement are already used up.

Incidentally, the braking force generator according to the invention works 10b as above with reference to 1 to 6 portrayed. This also applies to the discussed emergency operating situations, which also include a failure of the generator.

In an alternative application, the braking force generator 10 and 10b In the case of braking, the braking force generator is also activated from the beginning in addition to the generator braking. The deceleration effect of the generator braking is taken into account in the pedal actuation braking force generating characteristic of the control of the braking force generator. As a result, it can be achieved that a transition, which can be felt by the driver under certain circumstances, from a pure generator braking to a combined generator braking and braking system braking is prevented. Such a temporally parallel implementation of generator and brake system braking can for example take place in that the generator delays the wheels of a vehicle axle and the brake system initially only the wheels of the other vehicle axle delayed until the brake system finally - from a certain predetermined by the pedal operation delay limit - on all four wheels of the vehicle attacks and delays.

Claims (33)

Brake force generator ( 10 ) for a hydraulic vehicle brake system with - a force input element ( 14 ) which can be coupled or coupled with a brake pedal (P) and in a base housing of the braking force generator ( 10 ) is displaceable, - a master cylinder, in which a primary piston ( 64 ) is displaceable, wherein the primary piston ( 64 ) with the master cylinder a primary pressure chamber ( 132 ) is limited to produce a hydraulic brake pressure, - one with the force input member ( 14 ) connectable pedal counter force simulation device ( 106 ), - a pedal operation detection device ( 150 ) for detecting a pedal operation and - an actuating force generating means for exerting an actuating force on the primary piston ( 64 ), characterized in that the actuating force generating device is a control valve ( 22 ), a chamber arrangement ( 16 ) and an electromagnetic actuator ( 48 ), wherein the chamber arrangement ( 16 ) with a vacuum chamber ( 30 ) and one of the vacuum chamber ( 30 ) by a movable wall ( 28 ) and via the control valve ( 22 ) fluidically connectable working chamber ( 32 ) is formed and wherein the control valve ( 22 ) in accordance with the detected pedal actuation by the electromagnetic actuator ( 48 ) for achieving an operating force determining pressure difference between the working chamber ( 32 ) and the vacuum chamber ( 30 ) is controllable. Brake force generator ( 10 ) according to claim 1, characterized in that the current position of the movable wall ( 28 . 40 ) by means of a position sensor ( 140 ) is detected. Brake force generator ( 10 ) according to claim 1 or 2, characterized in that the pedal operation detecting means ( 150 ) has a sensor for detecting a current deflection of the brake pedal (P), in particular a on an axis of rotation of the brake pedal (P) arranged rotational angle sensor comprises. Brake force generator ( 10 ) according to one of the preceding claims, characterized in that the vacuum chamber ( 32 . 38 ) for generating a negative pressure with the intake tract of an internal combustion engine or with a vacuum pump ( 156 ) is fluidly connected. Brake force generator ( 10 ) according to one of the preceding claims, characterized in that the electromagnetic actuator ( 48 ) one on the control valve housing ( 24 ) fixed coil ( 46 ) and by means of the coil ( 46 ) relative to this displaceable magnetic armature ( 50 ) having. Brake force generator ( 10 ) according to one of the preceding claims, in particular according to claim 5, characterized in that the control valve ( 22 ) relative to the base housing ( 20 ) displaceable control valve housing ( 24 ) and a relative to the control valve housing ( 24 ) displaceable control valve element ( 58 ), wherein on the control valve housing ( 24 ) in sealing engagement with the control valve element ( 58 ) can be brought housing sealing seat ( 62 ) is provided, wherein further with the electromagnetic actuator ( 48 ), in particular with its anchor ( 50 ), a control valve sleeve ( 26 ), in which a sealing engagement with the control valve element ( 58 ) removable sleeve sealing seat ( 60 ) is provided. Brake force generator ( 10 ) according to claim 6, characterized in that when close concern of control valve element ( 58 ) and sleeve sealing seat ( 60 ) and simultaneously separated control valve element ( 58 ) and housing sealing seat ( 62 ) the working chamber is fluidically connected to the vacuum chamber and that when the control valve element ( 58 ) and housing sealing seat ( 62 ) and at the same time separated control valve element ( 58 ) and sleeve sealing seat ( 60 ) for establishing a differential pressure between the working chamber ( 32 . 38 ) and the vacuum chamber ( 30 . 36 ) the working chamber ( 32 . 38 ) is fluidly connected to the ambient atmosphere. Brake force generator ( 10 ) according to claim 5 and one of the preceding claims, characterized in that between the force input member ( 14 ) and one the control valve ( 22 ) actuating component, in particular the armature ( 50 ), a safety game (s) is provided, which in the absence of relocation of the anchor ( 50 ) through the coil ( 46 ) is overcome despite actuation of the brake pedal, so that the control valve ( 22 ) actuating component, in particular the armature ( 50 ), with the force input element ( 14 ) can be coupled force-transmitting, wherein an induced by a brake pedal actuation further displacement of the force input element ( 14 ) directly on the control valve ( 22 ) actuating component, in particular the armature ( 50 ), and subsequently to the control valve housing ( 24 ) is transmitted. Brake force generator ( 10 ) according to one of the preceding claims, characterized in that the chamber arrangement ( 16 ) is formed as a tandem chamber arrangement with a first chamber arrangement and a separate from this second chamber arrangement, wherein the first chamber arrangement, a first vacuum chamber ( 32 ) and one of these by a first movable wall ( 28 ) separate first working chamber ( 30 ), wherein the second chamber arrangement further comprises a second vacuum chamber ( 36 ) and one of these by a second movable wall ( 40 ) separate second working chamber ( 38 ), wherein the first and second chamber arrangement via the control valve ( 22 ) can be acted upon with pressure. Brake force generator ( 10 ) according to claim 9, characterized in that the first movable wall ( 28 ) and the second movable wall ( 40 ) are coupled together for the purpose of a common movement, preferably rigidly. Brake force generator ( 10 ) according to one of the preceding claims, characterized in that the force input member ( 14 ) via a transfer piston assembly ( 52 . 56 . 76 ) with the pedal counter force simulation device ( 106 ) is coupled. Brake force generator ( 10 ) according to one of the preceding claims, characterized in that the pedal counter-force simulation device ( 106 ) via a pedal counterforce hydraulic system ( 74 . 80 . 82 . 108 ) with a damper arrangement ( 110 . 114 . 124 ) is coupled force-transmitting. Brake force generator ( 10 ) according to claim 12, characterized in that the damper assembly is one via the by the pedal counter-force hydraulic system ( 74 . 80 . 82 . 108 ) displaceable power piston ( 110 ) compressible simulation spring ( 114 ) and / or fluidic damping means, preferably a throttle ( 126 ), or / and a rubber-elastic stop disc ( 124 ) having. Brake force generator ( 10 ) according to claim 12 or 13, characterized in that the damper arrangement in the cylinder housing ( 18 ) is integrated or mounted as a separate assembly to this. Brake force generator ( 10 ) according to one of the preceding claims, characterized in that the pedal counter-force hydraulic system with a controllable isolation valve ( 82 ) is formed, which in a first position, preferably in its passive position, the damper assembly and the transmission piston assembly hydraulically decoupled from each other and allows a substantially undamped movement of the transmission piston assembly and in a second position, preferably its active position, the damper assembly and the transmission piston assembly hydraulically with each other coupled. Brake force generator ( 10 ) according to claim 15, characterized in that the separating valve ( 82 ) with a throttle element ( 105 ), preferably provided with a spring-biased orifice, which in the active position of the separating valve ( 82 ) throttles a hydraulic fluid flow to the damper assembly. Brake force generator ( 10 ) according to claim 15 or 16, characterized in that the separating valve ( 82 ) is switched from its passive position to its active position at the beginning of a brake pedal operation and the control is switched from its active position to its passive position only after completion of the brake pedal operation. Brake force generator ( 10 ) according to one of the preceding claims, characterized that the master cylinder in a cylinder housing ( 18 ), preferably as a cylinder bore open on one side ( 66 ), is trained. Brake force generator ( 10 ) according to claim 18, characterized in that the cylinder housing ( 18 ) together with the components arranged therein as an assembly in the base housing ( 20 ) is inserted and connected to this releasably. Brake force generator ( 10 ) according to one of the preceding claims, characterized in that in the master brake cylinder, a secondary piston ( 130 ) displaceable is that the secondary piston ( 130 ) with the master cylinder a secondary pressure chamber ( 134 ) for generating a hydraulic brake pressure, and that the primary piston ( 64 ) with the master cylinder and the secondary piston ( 130 ) for generating a hydraulic brake pressure, the primary pressure chamber ( 132 ). Brake force generator ( 10 ) according to claim 20, characterized in that the primary piston ( 64 ) and optionally the secondary piston ( 130 ) by means of these associated biasing springs ( 136 . 138 ) are biased respectively in a starting position. Brake force generator ( 10 ) according to claim 11 and one of the preceding claims, characterized in that the primary piston ( 64 ) is provided with a through hole in which an actuating piston ( 68 ) is guided, wherein the actuating piston ( 68 ) an actuating cylinder bore ( 70 ), in which a separating piston ( 72 ) and by means of the transfer piston arrangement ( 52 . 56 ) is displaceable, wherein the separating piston ( 72 ) in the actuating piston ( 68 ) a hydraulic fluid chamber ( 74 ) which is fluidically connected to the hydraulic system of the counterforce force simulation device ( 106 ) is coupled. Brake force generator ( 10 ) according to claim 22, characterized in that a separating piston ( 72 ) contacting component ( 54 ) of the transfer piston assembly with the separating piston ( 72 ) is magnetically and / or adhesively or / and releasably coupled by latching. Brake force generator ( 10 ) according to claim 22 or 23, characterized in that the actuating piston ( 68 ) relative to the primary cylinder ( 18 ). Brake force generator ( 10 ) according to one of the preceding claims, characterized by an electronic control device ( 154 ), which the pedal operation detecting means ( 150 ) and the electromagnetic actuator ( 48 ) in accordance with an output of the pedal operation detecting means (Fig. 150 ), preferably taking into account a predetermined characteristic or a predetermined characteristic field, controls. Brake force generator ( 10 ) according to claim 25, characterized in that the electronic control device ( 154 ) the electromagnetic actuator ( 48 ) in accordance with a in the hydraulic system of the Pedalge genkraft simulation device ( 106 ), for example, on the isolation valve ( 82 ), detects detected hydraulic pressure. Brake force generator ( 10 ) according to claim 26, characterized in that the electronic control device ( 154 ) the electromagnetic actuator ( 48 ) in response to a parameter determined by a vehicle control system, such as the distance to a preceding vehicle, the current hydraulic pressure in the brake system, the current deceleration, or the like. Brake force generator ( 10 ) according to one of claims 25 to 27, characterized in that the electronic control device ( 154 ) the electromagnetic actuator ( 48 ) in accordance with a temporal change of the output signal of the pedal operation detecting means (Fig. 150 ) and / or in the hydraulic system of the pedal counter-force simulation device ( 106 ), for example, on the isolation valve ( 82 ), detects detected hydraulic pressure. Brake force generator ( 10 ) according to one of claims 25 to 28, characterized in that the characteristic curve or the characteristic field is predefined or adaptable to detected operating parameters. Brake force generator ( 10 ) according to one of claims 25 to 29, characterized in that the electronic control device ( 154 ) the isolation valve ( 82 ) in accordance with an output of the pedal operation detecting means (Fig. 150 ). Brake force generator ( 10 ) according to one of claims 25 to 30, characterized in that the electronic control device ( 154 ) in the control of the electromagnetic actuator ( 48 ) an output signal of the position sensor ( 140 ) considered. Brake system for a motor vehicle with a braking force generator according to one of the preceding claims. Braking system according to claim 32, characterized in that the motor vehicle is formed with a generator used for deceleration and that the vehicle deceleration obtained upon activation of the generator is taken into account in the activation of the braking force generator.