DE102014222197A1 - Parking brake device for a motor vehicle and method for controlling the parking brake device - Google Patents

Abstract

A method is described for performing a parking brake operation in a motor vehicle having a hydraulic service brake and an automated parking brake. According to the invention, it is provided that with each parking brake operation, a braking force built up after activation of the parking brake operation is generated at least partially by the vehicle occupant.

Description

The present invention relates to a parking brake device for a motor vehicle and a method for driving the parking brake device, wherein the braking force is generated at least partially by a vehicle occupant.

Conventional parking brake systems are mechanically operated either by means of a handbrake lever or by means of a separate foot pedal. An alternative to this is provided by automated parking brake systems, so-called automated parking brakes (APB), in which the required parking brake force is provided either electromechanically or electrohydraulically.

From the prior art, for example, the DE 10 2007 029 927 A1 known. It is described herein that, in the context of a parking brake situation, the piston is hydraulically pretensioned until at least one clamping force on the brake disc requiring the parking brake force is achieved. Then is brought by Drehantreiben the spindle and displacement of the mother latter in abutment with the brake piston, so that this back, that can be supported with its side facing the fluid chamber on the mother.

Also, from the prior art the DE 10 2010 039 183 A1 known. This document relates to a method for securing an electrically operated parking brake, characterized by the following steps: monitoring an operating variable relevant for the proper operation of the parking brake, determining whether the operating size exceeds a predetermined threshold, and prompting the driver depending on the value of the operating size, a perform certain action, wherein the action includes engaging the gear or operating the service brake. Possible operating variables are the road gradient, the vehicle electrical system voltage and the brake temperature. Furthermore, the invention relates to a control device for carrying out the method described.

Increasingly, the trend in parking brakes is towards automation. However, since not inconsiderable expenses (in particular high-performance actuators for the provision of pressure or power, as well as control devices including security monitoring) have to be operated for the automated parking brake systems, these systems are relatively expensive for the customer or end customer. The object of the present invention is therefore to reduce the degree of automation in an automated parking brake system in order to design a cost-effective overall system.

This object is solved by the features of the independent claims. Further developments of the invention are specified in the dependent claims.

For this purpose, a method for carrying out a parking brake operation in a motor vehicle having a hydraulic service brake and an automated parking brake is described. According to the invention, it is provided that with each parking brake operation, a braking force built up after activation of the parking brake operation is generated at least partially by the vehicle occupant.

A parking brake operation is understood to be any operation that detects a vehicle. In particular, in this case a parking operation of a vehicle is to be understood in which the driver leaves the vehicle following this, in particular for a longer period of time. Furthermore, a parking brake operation may also refer to operations that allow a temporary holding a vehicle, for example, in a holding operation on the mountain. In a holding the driver usually sits in the vehicle.

The braking force to be established can be equated with a holding force of the vehicle and a clamping force between the brake piston and the brake discs, or be translated into this. The generation of the braking force should at least partially by the vehicle occupants, in particular by the driver done.

According to the invention, the braking force is generated during each parking brake operation and thus already during an initial parking brake operation. It is not necessary here that further conditions are met from which, for example, it is deduced that a single force component (for example a force component generated by means of an actuator) is insufficient and therefore another force component (for example a force component generated by the driver) ) necessary is. Such conditions could be a high slope of the parking level and / or a high temperature of the brakes.

The method provides in a further embodiment that a generation of a braking force by the vehicle occupant is also carried out in a subsequent Nachspannvorgang.

The parking brake operation is activated when a parking brake request is detected. A parking brake request can be made as a parking brake request of the driver by means of an actuation of an actuating element by the driver. An example of this is a manual Operation called known in his way Feststellbremstasters. The actuator can be installed anywhere in the driver's compartment. The actuating element is advantageously a different from the brake pedal of the service brake actuator. The button can be used to request an obstruction of the parking brake ("lock"), an unlocking this ("release") as well as the provision of an emergency delay. An emergency deceleration is performed when the driver activates the parking brake button at a higher speed (eg at more than 3 km / h). Due to the higher speed no parking brake operation is possible. The vehicle is delayed, however, if the button is pressed permanently. A parking brake operation can optionally be initiated subsequently as soon as the speed of the vehicle has been reduced (for example to less than 3 km / h). It may also be a parking brake request to be recognized if other specific circumstances indicate that there is currently a parking brake request of the driver or shortly a Feststellbremswunsch will arise.

In addition to the parking brake request of the driver and automated requirements of the parking brake power are conceivable. As an example of a possible requirement, the so-called hill-hold function is mentioned, in which the vehicle is temporarily held on the mountain at the existing position, for example, at a traffic light stop on a slope. For this purpose, an acceleration sensor can be provided. Such a can detect the slope of the holding situation, by means of the inclination of the vehicle at standstill of the vehicle.

According to the invention it is provided that the vehicle occupant cooperates in generating a braking force to be built up, which is built up after activation of the parking brake operation. This is to be understood that first an activation of the parking brake operation takes place and subsequently a braking force generation takes place in which, for example, the driver generates at least part of the force to be built up. Of course, the driver may already have been involved in the production of a braking force in advance of the activation or have performed this.

In particular, it is provided that the driver generates the braking force by means of the hydraulic service brake. Advantageously, it is provided that the braking force required after activation of the parking brake operation is completely established by means of the service brake. The braking force generated by means of hydraulic brake pressure by the service brake can be subsequently transferred to the automated electromechanical parking brake, or passed to this or taken from this.

The automated parking brake is designed, for example, as a "motor on caliper" system and combined with the service brake, or integrated into the system of the service brake. The parking brake may have a self-locking spindle drive, wherein the brake piston of the service brake by the tracking spindle in a deflected by the hydraulic pressure position supported back, i. is fixed. This can advantageously be done locking the deflected brake piston. The braking force built up by means of the service brake is thus maintained by means of the automated parking brake without having to maintain the corresponding force continuously by the driver or an actuator. Advantageously - in particular with regard to the reduced dimensioning and the associated cost reduction - it can be provided that essentially only one locking and no force build-up takes place by the actuation of the actuator of the parking brake.

To release the parking brake of the electromechanical adjustment mechanism is driven in the reverse direction, thereby releasing the parking brake locking mechanism again. This is designed in such a way that even a small torque is sufficient for loosening. Pressure support for the release function may also be provided by the driver or the hydraulic actuator as needed. In addition, the known function AVR (Automated Vehicle Release) is thus still available. The driver can e.g. Drive off the parking situation without rolling back on a slope.

Due to the described method existing components for the pressure generation of the hydraulic service brake can be designed unchanged, since only minimal additional loads occur. The components of the automated parking brake can continue to be designed less powerful and thus also smaller and cheaper. As an example of such a reduced design, reference is made to the motor gear unit of the parking brake, since this actuator no longer build up power, but only has to lock the end position of the brake piston.

In an advantageous embodiment it is provided that a structure of the braking force is initiated by the vehicle occupant by means of an actuation of the brake pedal of the service brake.

By this is meant that the generation of the braking force is initiated by, for example, the driver by means of a stepping of the brake pedal of the hydraulic service brake. During the activation of the parking brake operation by means of a separate actuating element, for example Switch takes place, the initiation of the power structure by means of the conventional brake pedal. The term "initiation" is understood to mean that the structure of the braking force is started by the driver by means of an operation of the brake pedal. In this case, advantageously existing components of the brake system can be used to avoid further switches or activation elements. The generation of the braking force, at least of the force component of the braking force provided by the driver, can be effected by the brake pressure built up by means of the actuation of the brake pedal. Furthermore, it can be used advantageously on the existing brake system to allow for the driver simple and effective braking force generation. Of course, the structure of the braking force by the driver by means of components of the brake system can receive appropriate support and reinforcement, for example. By means of a brake booster.

In an advantageous further development of the method, it is provided that a request is issued to the vehicle occupant to build up the braking force.

By this is meant that a direct or indirect information is output, which should ask the driver to build a braking force. Such information enables both informing the driver to perform such an activity and possibly reminding the driver to perform such activity. The method thereby increases the security of the detection process. The calculation of the braking force can be done in accordance with and taking into account the vehicle conditions (vehicle load, temperature of the brake discs, etc.) and environmental conditions (road gradient, Untergrundsmätte, etc.). The output of the information to the driver can be visual. In particular, symbols or graphic representations or short textual designations are suitable here. It is also possible to output an acoustic (eg voice output) or a haptic (eg brake pedal pulsation) request to the driver. Of course, combinations are possible. The respective request can be issued once, advantageously not burden the driver permanently with a known information. Furthermore, the request or at least one of the requests can also be issued until the built-up pressure corresponds to a pressure to be built up for the required braking force. By canceling the request upon reaching the destination request, the driver receives feedback for the successful fulfillment of the request. Advantageously, the driver can hereby be provided with safety-relevant information as to whether sufficient braking force has been achieved for the present parking brake operation.

In an alternative embodiment, it is provided that a further function / malfunction indication is implemented in the method. If an error or a malfunction is detected in the procedure or in the brake system, a corresponding information is output to the driver. The reaction can be carried out, for example, by means of a red or / and yellow functional lamp / warning lamp.

In a further advantageous embodiment, it is provided that information about the height of the present braking force and / or the amount of braking force to be established is output to the vehicle occupant.

While the above-described request to build a braking force provides a digital statement ("structure braking force necessary", "structure braking force not necessary"), the driver receives further information in this sense. For example, such information can represent the current braking force or the brake pressure currently prevailing in the brake system. Furthermore, it is also possible to output information about the required braking force or about the brake pressure to be reached. Such information may be given in absolute physical terms.

Advantageously, however, in the sense of customer orientation, only a quantity representing the physical variable is output, for example in the form of "brake pressure low and brake pressure high" or "brake pressure insufficient and brake pressure sufficient". This can also be a representation by means of a continuous bar from one expression to another. Alternatively, it is also possible to use interval levels, for example in the form of a three-level scale. These appear particularly suitable for gaining a simple understanding of the user. Here, the combination and use of a color coding in the form of a three-level traffic light circuit (green, yellow, red) appears advantageous. The customer is thus communicated intuitively and easily understood whether a sufficient brake pressure prevails in the system (green traffic light level) or not (red traffic light level) or the brake pressure is currently in a possibly unfavorable transition area (yellow traffic light level). Of course, the information output is adjusted according to the present braking force requirements. For example. At a lower slope of the parking level a lower brake pressure is necessary. Therefore, the green traffic light circuit is correspondingly already displayed at a lower built-up brake pressure. Different heights of the braking force to be achieved can Moreover, be implemented by means of a varied information presentation and / or request to the driver.

In an alternative embodiment, it is provided that in the event that the built-up braking force is insufficient, information is output to the vehicle occupant.

Similar to the previously described embodiment of the method, it can advantageously be provided that the driver receives direct safety-related information if the braking force prevailing in the system is insufficient to keep the vehicle as required. By such a configuration, the driver of the vehicle receives an immediate feedback regarding a successful fulfillment of the braking force request. It can also be avoided in this way that a - in this sense unnecessary - request is issued to the driver, although an already existing brake pressure is already sufficiently high. By avoiding unnecessary information as well as selecting and transmitting important information to the driver, the driver's load is reduced and relevant information brought into the focus of the driver. An output of such information can also be done, for example, optically, acoustically or haptically.

Of course, it is envisaged that this information output in the manner described above may also contain or represent a request to build up a braking force. Furthermore, it is also possible to output changed information and request in accordance with the required amount of braking force, or the brake pressure applied by the driver or the course of the brake pressure applied by the driver, in order to transmit specific information for the particular application case in question.

In a further advantageous embodiment of the method it is provided that an actuation of the parking brake is essentially started upon activation of the parking brake operation.

Based on activation of the parking brake operation, activation of the parking brake brake actuators may occur simultaneously or without significant delay. The activation of the actuators thus allows a permanent tracking of the parking brake upon actuation of the hydraulic service brake. The braking force generated by means of the service brake, can thereby advantageously directly, i. without pronounced time delay, are transferred to the automated parking brake. This can be done immediately maintaining a built-up braking force. The term "actuation" in this context is an activation to understand. Furthermore, a corresponding control can also be understood as an actuation. A tracking of the actuator of the parking brake during a force buildup in the brake device is advantageously provided by the service brake. In this case, the control can of course also include a method for controlling in order to avoid overloading of the actuator if necessary, for example by controlling the current and voltage values or the movement, in particular the rotational speed of the actuator.

In an advantageous embodiment, the method is characterized in that the structure of the braking force by means of an increase in pressure in the brake device, which is combined with the parking brake.

Under a braking device to be understood in this context, an association of components, which represents the brake system of a wheel of the vehicle. The brake device thus includes, for example, an inflow and outflow for a brake fluid, a brake caliper (also called brake caliper) formed brake housing, and a brake piston. In contrast to this, for example, a brake system may comprise a plurality of brake devices, the supply and discharge lines, as well as further actuators and a control device. Furthermore, in the motor vehicle at certain braking devices, an integration of a parking brake, which is designed as a motor-on-Caliper with an electric motor driven spindle present. For example. can each be an integrated parking brake on the two braking devices of the two wheels of the rear axle, while no parking brake is provided on the two braking devices of the two wheels of the front axle. Advantageously, it can now be provided that in the context of the method, i. in particular to direct the pressure generated by the driver to the braking devices, which are combined with a parking brake. The brake devices, which have no integrated parking brake, are not subjected to the generated hydraulic pressure. The pressure in these braking devices is thereby not further increased in the context of the method. A steering of the brake fluid can take place, for example, via a circuit of valves existing in particular in the brake system. Advantageously, a targeted focusing of the generated pressure on the relevant braking devices can be achieved by the steering of the fluid in the systems combined with parking brakes. Since the volumetric flow generated is constant, thereby faster achievement of the necessary pressure level can be achieved in these brakes, as if all braking devices are acted upon by the shifted brake fluid.

In a further advantageous embodiment, it is provided that the braking force is derived from information about a displacement of the parking brake.

This is to be understood that the adjustment of the parking brake is used as a direct reference value for a braking force achieved. Alternatively, the adjustment can also enter as an indirect variable in a calculation of the braking force. The traversed adjustment thus serves as a pressure comparison variable, which results from the total movement of the brake piston in the brake caliper at a corresponding pressure. As an adjustment can, for example, a travel of the spindle of the parking brake are considered. In this sense, the travel path is a basis for an estimated value of the braking force. Advantageously, a present braking force can thereby be estimated by means of simple methods and means without knowing the exact pressure variable in the system. The travel can be estimated, for example, by means of displacement sensors or rotational angle sensors or on the basis of the temporal control.

In an advantageous alternative embodiment can of course also be provided that the built-up braking force is derived from the present hydraulic brake pressure. For this purpose, the present brake pressure can be determined by means of pressure sensors. The pressure sensors can be used to measure a pre-pressure (especially in the master cylinder) or to measure a circular pressure or wheel pressure. Advantageously, sensors are used which are already integrated in the system in order to avoid additional expense.

In an advantageous embodiment of the method, it is provided that an actuator and / or a supporting component of a service brake system supports the braking force buildup.

As a service brake system, the entire system of the service brake should be understood. This usually extends to the brake pedal, a brake booster, the individual braking devices of the wheels and a driver assistance system for braking, in particular an ESP module with a hydraulic pump as an ESP actuator. Here is one of these components to assist the driver in the braking force and also generate a braking force. In this case, the use of an existing component is suitable for this, in order to keep the effort low.

Advantageously, in the event of insufficient provision of braking force by the driver, support should be provided by an automated component of the service brake. In particular, the ESP actuator of the ESP module appears to be suitable for assisting the driver in producing pressure by means of a build-up of hydraulic pressure in order to achieve the required target pressure.

Furthermore, the brake booster can generally help the driver to generate the required brake pressure. By means of a corresponding regulation, the brake booster can provide assistance even when the internal combustion engine is switched off. For example. In the case of a preceding driving cycle, a negative pressure can be present and stored in the brake booster which assists the driver in generating the braking force.

In an advantageous further development of the method it is provided that in order to support the braking force build-up, a pressure of a service brake system is locked as soon as it is detected that a parking brake request is present and / or the vehicle comes to a standstill.

This is understood to mean that a present at a certain time in the service brake system pressure level is maintained as soon as the vehicle comes to a stop or as soon as a parking brake request is detected. A pressure applied in the service brake system at this time can thereby be maintained, i. kept constant. This can be done, for example, by controlling valves of the service brake system. Of course, an increase in pressure by, for example, the driver continues and at any time. However, a reduction of the pressure may, for example, however, only take place if a starting request is detected. The description and possible determination of a "parking brake request" has already been explained. Also, the pressure of a service brake system may be locked when it is detected that the vehicle is stalling. For this purpose, for example, the speed profile of the vehicle can be evaluated. For detecting the vehicle speed, a wheel speed sensor may be provided.

According to the invention an automated parking brake for a motor vehicle is provided with a hydraulic service brake, wherein the parking brake is configured and has means for each Feststellbremsvorgang to produce after activation of the parking brake operation braking force at least partially by the vehicle occupant by means of the hydraulic service brake.

This is to be understood that the parking brake is designed according to that at each parking brake operation to be built up braking force at least partially, for example. The driver is produced. Such a design includes the implemented possibility of driver engagement as well as the correspondingly adapted design of the components of the parking brake. In this case, in particular a weaker power design of the actuator and the gear unit of the parking brake is referenced without having to make an adjustment to the actuator of the service brake to replace the generation of the required braking force. As a result, not only the components of the parking brake can be designed less powerful and thus smaller and cheaper. Also existing components of the hydraulic service brake can be used without any necessary adaptation designs, since only minimal additional loads occur. As a result, a cost-optimized overall system can be achieved.

• – eine nach jeder Aktivierung eines Feststellbremsvorgangs durch den Fahrzeuginsassen zu erzeugende Bremskraft aufzubauen, und/oder
• – eine nach jeder Aktivierung eines Feststellbremsvorgangs durch den Fahrzeuginsassen zu erzeugende Bremskraft aufzubauen, wenn die zu erzeugende Bremskraft nicht in hinreichendem Maße erzeugt wird, und/oder
• – wobei die Höhe der vorliegenden Bremskraft und/oder die Höhe der aufzubauenden Bremskraft an den Fahrzeuginsassen ausgegeben werden.

The invention also provides: A device for outputting information and / or a request to the vehicle occupant

• To build up a braking force to be generated by the vehicle occupant after each activation of a parking brake operation, and / or
• To build up a braking force to be generated by the vehicle occupant after each activation of a parking brake operation, if the braking force to be generated is not generated to a sufficient degree, and / or
• - Wherein the amount of the present braking force and / or the amount of braking force to be established are issued to the vehicle occupants.

This is to be understood as meaning that a device is provided which, for example, provides the driver with information to build up a specific braking force. This braking force is, for example, to be generated by the driver at each parking brake operation. The device transmits a corresponding request to the driver to carry this out. Such information enables both informing the driver to perform such an activity and possibly reminding the driver to perform such activity. The device thereby increases the security of the detection process. Alternatively or additionally, the device may also be designed in the event that the, i. the required braking force is not sufficient to provide the driver with information about it. As a result, the device makes it possible for the driver to transmit a request for possibly renewed or increased braking force generation only in the situations when the braking force is insufficient. The driver is therefore confronted with information only if further activity is necessary through him. In this sense, the device reduces the driver burden by reducing unnecessary information as well as selecting and transmitting important information. Furthermore, alternatively or additionally, the device is configured, for example, to communicate to the driver information about the height of the present braking force and / or the height of the braking force to be built up. For example. the driver can use the indicated difference, i. the delta between generated and generated force, easier to estimate what additional force is to be provided by him.

According to the invention, a control device is provided, which is set up and has means to carry out a method according to one of the preceding claims.

Further features and expediency of the invention will become apparent from the description of embodiments with reference to the accompanying figures.

From the figures shows:

1 a schematic sectional view of a braking device with a service brake and an automated parking brake in "motor on caliper"construction; and

2 a sequence of a control of the parking brake with a request to the driver to brake pressure generation; and

3 a sequence of a control of the parking brake by means of hydraulic assistance in the brake pressure generation.

1 shows a schematic sectional view of a braking device 1 for a vehicle. The brake device 1 has a service brake 14 on, by means of a to be operated by the driver Fußbremspedals 13 and a service brake actuator 10 can generate a braking force for locking the vehicle. Furthermore, an automated (automatic) parking brake 15 (Parking brake), which is a parking brake actuator 2 (Brake motor).

The automated parking brake 15 is, for example, designed as a "motor on caliper" system as shown and with a service brake 14 combined. You could also consider this as in the system of service brake 14 integrated view. Both the automated parking brake 15 as well as the service brake 14 grip on the same brake piston 5 as well as the same caliper 6 to build up a braking force, ie a clamping force on the brake disc 7 to create. The service brake 14 is thereby actuated by the driver by means of the Fußbremspedals. In such an operation, a predetermined clamping force between the brake pads 8th . 8th' and the brake disc 7 hydraulically constructed. To build up a braking force by means of the hydraulic service brake 14 becomes a medium 11 , In particular, a substantially incompressible brake fluid 11 , in a through the brake piston 5 and the caliper 6 limited fluid space pressed. The brake piston 5 is opposite the environment by means of a piston sealing ring 12 sealed. The service brake is in 1 as a hydraulic system with a service brake actuator 10 designed, wherein the actuator 10 may be formed by a brake booster, an ESP pump or a so-called iBooster. The force of the driver can, for example, by a trained as a brake booster actuator 10 the service brake 14 be strengthened. It is possible that it is in the illustrated actuator 10 also involves several actuators, for example, a brake booster and an ESP pump.

When the service brake is activated 14 First, the free travel or the clearance must be overcome before a braking force can be built. At the end of such a preparation phase are the brake pads 8th . 8th' to the brake disc 7 applied and the force builds up with a further shift of brake fluid 11 in the direction of the brake disc. 1 shows the state of the already overcome idle and clearance, the brake pads 8th . 8th' to the brake disc 7 are created.

Brake force generation in hydraulic system of service brake 14 takes place, for example, by a shift of brake fluid 11 by the driver by means of an operation of the foot brake pedal 13 , This braking force generation can be achieved by a brake booster 10 get supported. A clamping force generated in this way can subsequently be achieved by the electromechanical automated parking brake 15 taken over or handed over to this. In the case of a takeover by means of the service brake 14 Built-up braking force through the automated parking brake 15 becomes the parking brake actuator 2 driven. The actuator 2 drives for this purpose a spindle mounted in the axial direction 3 , in particular a threaded spindle 3 , at. At the end of the spindle 3 which is the actuator 2 is turned away, is the spindle 3 with a spindle nut 4 Mistake. The spindle nut 4 and the brake piston 5 are in a caliper 6 stored, which is a brake disc 7 Pliers overlapping. The spindle nut 4 is during a rotational movement of the actuator 2 and a resulting rotational movement of the spindle 3 shifted in the axial direction and on the brake disc 7 moved. The spindle nut 4 lies in the tensioned state of the automated parking brake 15 on the brake piston 5 at.

The parking brake actuator 2 and thus the movement of the spindle drive are stopped, for example, when the spindle nut 4 on the brake piston 5 is present, or it is charged with a specific force. Is the spindle nut lying 4 on an inner end face of the brake piston 5 (also called rear of the brake piston bottom or inner piston crown) on, the parking brake 15 due to the self-locking of the spindle drive without further control of the actuator 2 a force on the brake pads 8th . 8th' , or the brake disc 7 transfer. Also, in a locked by the spindle drive brake piston 5 one by means of this position of the brake piston 5 generated clamping force to be maintained after completion of the hydraulic power supply. This can be considered a takeover, or a transfer from the hydraulic service brake 14 to the automated electromechanical parking brake 15 be understood.

The activation of the brake actuators 2 and 10 takes place by means of an output stage, ie by means of a control unit 9 which may, for example, be a control unit of a vehicle dynamics system, such as ESP (electronic stability program) or another control unit.

2 shows a sequence of a control of the parking brake with a request to the driver to brake pressure generation. The method begins with a first step S1, in which the vehicle is brought to a standstill, or at least below a defined speed threshold (eg 3 km / h). In a second step S2, an operating element is actuated, for example an actuation of a button in the direction of "locking". In an embodiment of this step, a further step S3, in which the information is transmitted to the driver, that he must provide a corresponding holding force. Furthermore, the driver information about the current state, ie the currently present holding power, are transmitted. Such a combined information can, for example, by means of a visual indication in the form of a graphic representation of bars, in particular color bars done. The bars indicate whether the current holding force is sufficient. The evaluation of the holding force can be done via the existing or provided in the system, hydraulic pressure. Likewise, a color coding of the said bars can take place, wherein the color red can represent an insufficient holding force, the color yellow an almost sufficient holding force and the color green a sufficient holding force. Furthermore, based on the step S2, a step S4 can be activated, in which a parking brake actuator, for example an electromechanical motor, is actuated. The activation of the actuator allows a permanent as well as an immediate tracking of the parking brake upon actuation of the hydraulic service brake by the driver. As a result, the pressure support required by the driver for the parking brake operation is only required for a short time. The activation of the actuator can be done in dependence on the operation of the service brake. Furthermore, it is checked in a function S5 whether the existing or provided in the system hydraulic pressure is below a defined threshold. If so, a red bar is displayed to the driver, as shown at S71 by a crossed hatching. If it should be determined in S5 that the existing hydraulic pressure is not below the defined threshold, it is checked in a function S6 whether the existing pressure is sufficient to provide the defined holding force. If this is not the case, a yellow bar is displayed to the driver, as shown in S72 by means of dotted hatching. If the existing pressure is sufficient, a green bar is displayed to the driver, as shown in S73 by means of a linear hatching. Furthermore, in one step 8th the control of the parking brake actuator ends. Alternatively or in addition to the representation of the color bars, the driver can also be given a different visual, haptic and / or acoustic feedback about the current situation. For example, in an alternative embodiment, an information representation by means of color coding of a signal element - instead of multiple bars - done. Of course, the information may also be a request or be associated with such a request to reinforce the pressure support, or to perform again if the driver should have already finished this.

3 shows a sequence of a control of the parking brake by means of hydraulic assistance in the brake pressure generation. In principle, this is based on the procedure already described, which, however, is extended by means of several steps. For the steps S1 to S8 including the representation alternatives S71 to S73, reference is made to the above statements. The extended method provides a timer, which is started in a step S9 and measures a certain period of time. In one step 10 It is checked whether the time has expired and the required pressure to provide the desired holding force is not reached. If this is the case, a hydraulic actuator is activated in a step S11. This is in particular the ESP pump. The control takes place until the existing pressure in the system is sufficient to provide the required holding force. Once this target pressure is reached, the control of the hydraulic actuator is terminated.

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 102007029927 A1 [0003]
• DE 102010039183 A1 [0004]

Claims (13)

Method for carrying out a parking brake operation in a motor vehicle with a hydraulic service brake ( 14 ) and an automated parking brake ( 15 ), characterized in that at each parking brake operation, a braking force built up after activation of the parking brake operation is at least partially generated by the vehicle occupant. A method according to claim 1, characterized in that a structure of the braking force by the vehicle occupant by means of an actuation of the brake pedal ( 13 ) of the service brake is initiated. A method according to claim 1, characterized in that a request is issued to the vehicle occupant to build up the braking force. A method according to claim 1, characterized in that information about the amount of the present braking force and / or the amount of braking force to be established is output to the vehicle occupant. A method according to claim 1, characterized in that in the event that the built-up braking force is not sufficient, information is output to the vehicle occupant. A method according to claim 1, characterized in that an actuation of the parking brake is started substantially at the activation of the parking brake operation. A method according to claim 1, characterized in that the structure of the braking force by means of an increase in pressure in a braking device ( 1 ), which is combined with the parking brake. A method according to claim 1, characterized in that from information about a displacement of the parking brake, the braking force is derived. Method according to claim 1, characterized in that an actuator ( 10 ) and / or a supporting component of a service brake system to assist braking power buildup. A method according to claim 1, characterized in that in support of the braking force build-up, a pressure of a service brake system is locked as soon as it is detected that a parking brake request is present and / or the vehicle comes to a standstill. Automated parking brake ( 15 ) for a motor vehicle with a hydraulic service brake ( 14 ), characterized in that the parking brake ( 15 ) and has means for at each parking brake operation to be established after activation of the parking brake operation braking force at least partially by the vehicle occupant by means of the hydraulic service brake ( 14 ) to create. Device for outputting information and / or a request to the vehicle occupant To build up a braking force to be generated by the vehicle occupant after each activation of a parking brake operation, and / or To build up a braking force to be generated by the vehicle occupant after each activation of a parking brake operation, if the braking force to be generated is not generated to a sufficient degree, and / or - Wherein the amount of the present braking force and / or the amount of braking force to be established are issued to the vehicle occupants. Control device, which is set up and has means to carry out a method according to one of the preceding claims.

Images