Control device and method for operating an external force braking system of a vehicle

Abstract

The invention relates to a control device and a method for operating an external force brake system of a vehicle. The invention also relates to an external force brake system, in particular an axle brake module, for a vehicle.

Description

Technical Field

[0001] This invention relates to control devices for external braking systems of vehicles. Similarly, this invention relates to external braking systems for vehicles, particularly axle braking modules. Furthermore, this invention also relates to methods for operating external braking systems of vehicles. Background Technology

[0002] Modern vehicles are equipped with a central braking system architecture. This architecture is typically divided into actuation (braking force enhancement), modulation (ESP), and base (wheel brakes). In actuation, the driver's pedal force is increased, for example, through electromechanical braking force enhancement, while individualized brake pressure regulation for each wheel is usually achieved in a secondary braking module (ESP). Newer systems additionally enable driver decoupling in fault-free conditions, which can improve regenerative braking (brake management) and pedal feel. However, such systems still provide a mechanical backup stage in case of failure, whereby the driver is mechanically or hydraulically coupled to the wheel brakes. These systems are implemented either as an integrated brake modulation unit or as two separate units.

[0003] In the future, so-called True-by-Wire systems are relevant, where driver expectations are detected via an electrically connected brake pedal. These systems do not have a mechanical backup stage. Currently, a central braking system architecture is used. The required redundancy is achieved by using a box with integrated redundancy or by using two boxes with corresponding brake actuators. However, all four wheels of the vehicle are always supplied with braking pressure in the center. Alternatives to the central architecture (where all four wheels are connected to one or two intermediate boxes) can also be achieved using so-called steerable axle modules. These generate braking pressure for the corresponding two wheels on the axle. This eliminates the long brake cable from the motor housing to the rear axle. This provides flexibility in wheelbase and manufacturing.

[0004] Furthermore, electromechanical braking systems (EMBs) can also be mass-produced in the future. These EMBs can be incorporated into so-called distributed braking systems, where a corresponding brake actuator (motor drive unit) is responsible for generating braking torque on the same wheel. For some vehicles, the braking force provided by the EMB may be insufficient, thus hydraulic wheel actuators (motor pumps or motor piston units (with valves if necessary)) are also conceivable. The actuators of distributed braking systems are typically mounted directly on the wheels, or at least near them. Distributed systems offer advantages in adjustability through the complete independence of the two wheel modules on the axle, and packaging advantages through the variable free space in the motor compartment and the elimination of brake cables, which must be laid across the vehicle in conventional braking systems. Furthermore, brake fluid and its replacement can also be eliminated in EMBs.

[0005] Different layouts and redundancy concepts are known. For example, DE 10 2004 052 783 A1 describes a method and apparatus for stabilizing the driving state of an all-wheel-drive vehicle. To further improve the stability of the vehicle relative to known slip adjustment or ESP systems, it is suggested to perform the following steps: determine the adjustment difference between the actual torque currently present on the wheel or axle and a preset rated torque for the wheel or axle of the vehicle; obtain the maximum possible force engagement between the tire associated with the wheel or axle and the road, the tire currently rolling on the road, within the adjustment difference; change the initially preset rated torque for the wheel or axle to a value represented by the change through the obtained maximum force engagement; and adjust the actual torque to the changed rated torque.

[0006] Furthermore, DE 10 2020 216 322 A1 describes a braking system for a vehicle with at least two axles, comprising a first axle unit having a first electric brake pressure amplification device, a first wheel brake cylinder hydraulically connected to the first electric brake pressure amplification device and mounted on a first wheel of the first axle of the vehicle, and a second wheel brake cylinder hydraulically connected to the first electric brake pressure amplification device and mounted on a second wheel of the first axle; and a second axle unit hydraulically decoupled from the first axle unit, wherein the first axle unit has a second electric brake pressure amplification device in addition to the first electric brake pressure amplification device, and the first wheel brake cylinder and the second wheel brake cylinder are hydraulically connected to the second electric brake pressure amplification device. The present invention also relates to a method for using a braking system for a vehicle operating with at least two axles.

[0007] Known dual-axle modules suffer from the drawback that different adjusters must be operated using different strategies depending on the desired wheel torque. Therefore, the advantage of the EMB (Electronic Wheel Module) in independently and freely adjusting wheel torque cannot be realized on the front axle wheels. This leads to disadvantages in the central architecture, as it is built on the basis of individualized wheel adjustments. Summary of the Invention

[0008] The present invention provides a control device for an external braking system for a vehicle according to the present invention, an external braking system for a vehicle according to the present invention, and a method for operating an external braking system for a vehicle according to the present invention.

[0009] According to a first aspect of the invention, a control device for an external braking system of a vehicle is provided. The control device includes a main electronic device designed and / or programmed such that a motor of an electric piston cylinder device of the external braking system can be operated by means of the main electronic device, such that at least one fluid-containing volume of the electric piston cylinder device can be changed by means of the operated motor. Furthermore, at least one first valve and at least one second valve of the external braking system can be switched by means of the main electronic device, wherein a first wheel brake cylinder of the external braking system is connected to at least one fluid-containing volume via at least one first valve, and a second wheel brake cylinder of the external braking system is hydraulically connected to at least one fluid-containing volume via at least one second valve. Additionally, the main electronic device is designed and / or programmed such that a brake pressure holding or brake pressure increasing function for the first wheel brake cylinder and a brake pressure decreasing function for the second wheel brake cylinder can be performed simultaneously by means of the main electronic device: at least while brake fluid transmission from the first wheel brake cylinder to at least one fluid-containing volume increased by means of the operated motor is prohibited by means of at least one first valve switched to closed, brake fluid can be drawn from the second wheel brake cylinder into at least one increased fluid-containing volume via at least one second valve switched to at least partially open. The control device also includes secondary electronic devices designed and / or programmed such that, in the event of an electrical failure in the external braking system, the secondary electronic devices can either control the motor so that at least one fluid-containing volume of the electric piston cylinder device can be changed by means of the controlled motor, thereby enabling the performance of a brake pressure holding or brake pressure increasing function for the first wheel brake cylinder and the second wheel brake cylinder; or allow at least one first valve and at least one second valve to be switched so that the performance of a brake pressure holding or brake pressure increasing function for the first wheel brake cylinder and the second wheel brake cylinder.

[0010] According to a second aspect of the invention, an external braking system for a vehicle is provided, particularly an axle braking module. The external braking system includes control equipment according to a first aspect of the invention. Furthermore, the external braking system includes an electric piston cylinder device, the motor of which can be operated by means of primary and secondary electronics of the control equipment, such that at least one fluid-containing volume of the electric piston cylinder device can be changed by means of the operated motor. Furthermore, the external braking system includes a first wheel brake cylinder arranged or potentially arranged on an axle of the vehicle and a second wheel brake cylinder arranged or potentially arranged on an axle of the vehicle. Furthermore, the external braking system includes a first valve and a second valve switchable by means of primary and secondary electronics, wherein the first wheel brake cylinder is connected to at least one fluid-containing volume via at least one first valve, and the second wheel brake cylinder is hydraulically connected to at least one fluid-containing volume via at least one second valve.

[0011] According to a third aspect of the invention, a method is provided for operating an external braking system for a vehicle. The method simultaneously performs a function of maintaining or increasing the braking pressure of a first wheel brake cylinder arranged on the axle of the vehicle for the external braking system, and a function of decreasing the braking pressure of a second wheel brake cylinder arranged on the axle of the vehicle for the external braking system. The method further includes the following steps:

[0012] An electric piston cylinder device that controls an external braking system, thereby increasing at least one liquid-containing volume of the electric piston cylinder device by means of the controlled motor.

[0013] Switch at least one first valve of the external braking system such that while the first wheel brake cylinder is hydraulically connected to at least one liquid reservoir via at least one first valve, the transmission of brake fluid from the first wheel brake cylinder to at least one liquid reservoir increased by means of a controlled motor is prohibited by means of at least one first valve that has been switched to be closed.

[0014] Switching at least one second valve of the external braking system such that, while the second wheel brake cylinder is hydraulically connected to at least one liquid containment volume via at least one second valve, brake fluid is drawn from the second wheel brake cylinder into the increased at least one liquid containment volume via at least one second valve that has been switched to at least partially open.

[0015] In the event of an electrical fault in an external braking system, secondary electronic devices or

[0016] - Controlling the motor causes a change in at least one fluid-containing volume of the electric piston cylinder device, thereby performing a function of maintaining or increasing the braking pressure for the first and second wheel brake cylinders; or

[0017] - Switch at least one first valve and at least one second valve to perform a function of maintaining or increasing the brake pressure for the first wheel brake cylinder and the second wheel brake cylinder.

[0018] The present invention is based on the concept of providing a control device or adjustment device and an axle braking module having such a control device, wherein the control device operates two electrically and spatially separated actuator or actuator modules, enabling independent and NVH-optimized control of the braking torque of the two wheels.

[0019] Electrical fault conditions may involve, for example, the electric piston cylinder device or one of the first or second valves. An advantage of the invention is that the braking pressure of the first and second wheel brake cylinders can be adjusted wheel-specifically and, additionally, with noise optimization, particularly lower noise. For example, the braking torque on a wheel or wheel brake cylinder can be reduced by means of the control device according to the invention: in wheels with higher braking pressure, the braking pressure is locked by activating the associated first valve, and subsequently, in wheels where the hydraulic braking torque should be reduced, the braking pressure is reduced by the electric piston cylinder device.

[0020] Advantageously, the present invention utilizes an electric piston cylinder device, often already used in external braking systems, to control the individualized braking torque of the wheels, thus eliminating the need for hardware expansion of the corresponding external braking system to implement the invention. Alternatively, it is generally sufficient to reprogram only the control device of the corresponding external braking system to perform the invention. This facilitates the use of the invention across multiple different vehicle types.

[0021] Another advantage of this invention is that, in external braking systems equipped with electric piston cylinder devices, the driver of a vehicle equipped with such a system (typically) does not perform braking operations on the external braking system. Therefore, the driver, who alternatively operates the simulator by manipulating the brake control element / brake pedal, is not bothered when simultaneously using the electric piston cylinder device of the external braking system to achieve the function of reducing brake pressure. Thus, this invention also provides the driver with a standard brake operation feel / pedal feel.

[0022] Advantageous design options and improvements can be obtained from the additional dependent claims and the description with reference to the accompanying drawings.

[0023] According to an improved embodiment of the invention, the main electronic device is additionally designed and / or programmed such that it can simultaneously perform a function to increase the brake pressure of the first wheel brake cylinder and a function to decrease the brake pressure of the second wheel brake cylinder by means of the main electronic device: While the transmission of brake fluid from the first wheel brake cylinder to at least one increased fluid capacity volume via a controlled motor is prohibited by means of at least one first valve switched to closed, and brake fluid can be drawn from the second wheel brake cylinder into at least one increased fluid capacity volume via at least one second valve switched to at least partially open, the pump motor of at least one pump of the external braking system can additionally be activated by means of the main electronic device, so that brake fluid can be pumped into the first wheel brake cylinder by means of at least one activated pump. The control device utilizes this principle that when the external braking system is equipped with an electric piston cylinder device and at least one pump as its two regulators or actuators, the operation of at least one pump is not / almost unaffected by closing at least one first valve. Therefore, the electric piston cylinder device can be used to decrease the brake pressure in the second wheel brake cylinder, and simultaneously, at least one pump can be used to increase the brake pressure in the first wheel brake cylinder. In this way, the braking torque on the wheel or wheel brake cylinder can be reduced, while the braking torque on other wheels or wheel brake cylinders on the same axle can be increased.

[0024] According to an improved embodiment of the invention, the main electronic device is additionally designed and / or programmed such that, by means of the main electronic device, a first brake pressure reduction function having a first rated gradient for the first wheel brake cylinder and a second brake pressure reduction function having a second rated gradient higher than the first rated gradient can be simultaneously performed: during the transmission of brake fluid from the second wheel brake cylinder to at least one increased fluid capacity via at least one second valve switched to at least a partially open position by means of an operated motor, the transmission of brake fluid from the first wheel brake cylinder to the increased fluid capacity is interrupted multiple times by means of at least one first valve switched to a short-term closed position. Therefore, simultaneous reduction of braking torque on both wheel brake cylinders can be achieved with different rated gradients. In the wheel or wheel brake cylinder with higher braking pressure, the target braking pressure can be set by changing the flow rate of the first valve, and in the wheel or wheel brake cylinder with lower target braking pressure, the target braking pressure can be adjusted by an electric piston cylinder device or piston.

[0025] According to an improved embodiment of the invention, the main electronic device is additionally designed and / or programmed such that, by means of the main electronic device, a first brake pressure increase function with a first rated gradient for the first wheel brake cylinder and a second rated gradient first brake pressure increase function with a higher rated gradient for the second wheel brake cylinder can be simultaneously performed by means of the main electronic device: a motor can be activated to realize the transfer of brake fluid from a reduced fluid containment volume by means of the controlled motor to the first and second wheel brake cylinders, wherein a first valve is controlled according to the first rated gradient. In this way, the braking torque increase of the two wheel brakes on the common axle can be achieved with different rated gradients. Here, while holding the other wheels, the braking pressure in the lower wheel can decrease proportionally more slowly.

[0026] According to another improvement of the invention, the control device is configured as a central controller for the vehicle. Furthermore, the third wheel brake cylinder of another axle of the vehicle can be coupled to the control device, particularly the central controller. Therefore, the central controller can control the wheel brake cylinder connected to it, as if the vehicle were equipped with four distributed brake actuators.

[0027] According to another improvement of the invention, the axle configuration is a rear axle of a vehicle, wherein an electric piston cylinder device, at least one first valve and at least one second valve are arranged on the rear axle.

[0028] According to another improvement of the invention, the function of increasing the braking pressure for the first wheel brake cylinder and the function of decreasing the braking pressure for the second wheel brake cylinder are performed simultaneously by means of the following measures: while the transmission of brake fluid from the first wheel brake cylinder to at least one fluid-containing volume increased by means of a controlled motor is prohibited by means of at least one first valve that is switched to be closed, and while brake fluid is drawn from the second wheel brake cylinder into at least one increased fluid-containing volume through at least one second valve that is switched to be at least partially open, the pump motor of at least one pump of the external force braking system is additionally activated, so that brake fluid is pumped into the first wheel brake cylinder by means of at least one activated pump.

[0029] According to another improvement of the invention, a first brake pressure reduction function having a first rated gradient for the first wheel brake cylinder and a second brake pressure reduction function having a second rated gradient for the second wheel brake cylinder are performed simultaneously by means of the following measures: during the transmission of brake fluid from at least one reduced liquid containment volume to the second wheel brake cylinder through at least one second valve switched to at least partially open, the transmission of brake fluid from the reduced at least one liquid containment volume is interrupted multiple times by means of at least one first valve switched to short-term closed.

[0030] According to another improvement of the present invention, a first brake pressure increase function having a first rated gradient for the first wheel brake cylinder and a second brake pressure increase function having a second rated gradient for the second wheel brake cylinder are simultaneously performed by means of the following measures: the motor is activated to realize the transfer of brake fluid from the reduced liquid containment volume by means of the controlled motor to the first wheel brake cylinder and the second wheel brake cylinder, wherein the first valve is controlled according to the first rated gradient.

[0031] The inventive concept described above is then reiterated and supplemented with other terms. This concept (shown simplified) relates to an axle braking module with an adjusting device or control unit that operates two electrically and spatially separated actuator modules or actuators, enabling independent and NVH-optimized control of the torque of the two wheels. Here, the adjusting device has primary and secondary adjusters or electronic devices, wherein the primary adjuster coordinates the two actuators in a fault-free state. Furthermore, wheel-individualized braking pressure is NVH-optimized, wherein the adjustment is based on gradients. In the event of an electrical failure or malfunction of one of the two adjusting modules or actuator modules, the remaining intact actuator can be used to brake the two wheels of the axle. Attached Figure Description

[0032] The invention will then be described with reference to the accompanying drawings. In the drawings:

[0033] Figure 1 A schematic diagram illustrating an implementation of an external braking system or a control device interacting with it is shown; and

[0034] Figure 2 A flowchart illustrating an implementation method for a method of using an external braking system for operating a vehicle is shown.

[0035] In the accompanying drawings, the same reference numerals denote the same or functionally identical parts unless otherwise specified. The numbering of method steps is for overview purposes and should generally not imply a specific temporal order. In particular, multiple method steps may be performed simultaneously. Detailed Implementation

[0036] Further advantages, features and details of the invention will become apparent from the following description, in which different embodiments are described in detail with reference to the accompanying drawings.

[0037] Figure 1 A schematic diagram of an embodiment of an external braking system or a control device 10 interacting with it is shown.

[0038] It should be noted that the usability of the control device 10 and the external braking system interacting therewith is not limited to a specific vehicle / motor vehicle type. Instead, the control device 10 and the external braking system can be installed on (almost) any vehicle / motor vehicle having two wheels mounted on a common axle. Vehicles equipped with the external braking system can be, for example, passenger cars, vans, and off-road vehicles.

[0039] Figure 1 The external braking system has a first wheel brake cylinder 12a and a second wheel brake cylinder 14a, wherein the first wheel of the vehicle decelerates / can decelerate by means of the first wheel brake cylinder 12a, and the second wheel of the vehicle decelerates / can decelerates by means of the second wheel brake cylinder 14a. For the braking pressure present in the first wheel brake cylinder 12a, the maximum value can be defined as a first maximum braking pressure, and the minimum value can be defined as a first minimum braking pressure. Correspondingly, for the braking pressure present in the second wheel brake cylinder 14a, its maximum value is called a second maximum braking pressure, and its minimum value is called a second minimum braking pressure.

[0040] The control device 10, which interacts with the external braking system, can be at least a part of the external braking system or at least one unit that is separately mounted / installable from the external braking system. Although the control device 10 is in Figure 1 While shown as a single-piece control unit, the constructibility of the control device 10 is not limited to this. Therefore, the functions performed by the control device 10 or its main and secondary electronic devices 10a, 10b can also be performed by multiple separate units.

[0041] The main electronic device 10a of the control device 10 is designed and / or programmed such that the motor M of the electric piston cylinder device 20 of the external braking system, at least one first valve 22a, and at least one second valve 22b are controlled / operable by means of the main electronic device 10a. The motor M of the electric piston cylinder device 20 can be controlled / operable by means of at least one motor control signal 11a output from the main electronic device 10a, such that at least one linearly adjustable piston 20a and 20b of the electric piston cylinder device 20 is adjustable / adjustable by means of the controlled motor M, such that at least one liquid containment volume 20c and 20d (in their dimensions) limited by at least one piston 20a and 20b can be varied / variable. The electric piston cylinder device 20 may be, for example, a DPB (decoupled power brake) device. In particular, the first brake circuit 16 of the external braking system can be hydraulically connected to the first liquid containment volume 20c, and the second brake circuit 18 of the external braking system can be hydraulically connected to the second liquid containment volume 20d of the electric piston cylinder device 20.

[0042] First and second valves 22a and 22b, switchable by means of a main electronic device 10a, are arranged on the external braking system such that a first wheel brake cylinder 12a is hydraulically connected to at least one liquid containment volume 20c and 20d via at least one first valve 22a, and a second wheel brake cylinder 14a is hydraulically connected to at least one liquid containment volume 20c and 20d via at least one second valve 22b. At least one first valve 22a can be switched by means of at least one first valve switching signal 11c output by the main electronic device 10a. Correspondingly, at least one second valve 22b is switched by means of at least one second valve switching signal 11d output by the main electronic device 10a. Advantageous embodiments of the first valve 22a and the second valve 22b will be discussed subsequently.

[0043] Furthermore, the main electronic device 10a is designed and / or programmed to simultaneously perform a brake pressure holding or increasing function for the first wheel brake cylinder 12a and a pressure decreasing function for the second wheel brake cylinder 14a. To simultaneously perform the brake pressure holding or increasing function for the first wheel brake cylinder 12a and the brake pressure decreasing function for the second wheel brake cylinder 14a, the motor M of the electric piston cylinder device 20 is controlled by the main electronic device 10a, such that at least one fluid containment volume 20c and 20d of the electric piston cylinder device 20 is increased by adjusting at least one piston 20a and 20b by means of the controlled motor M. Simultaneously, while brake fluid transfer from the first wheel brake cylinder 12a to the increased at least one fluid containment volume 20c and 20d is prohibited by means of at least one first valve 22a switched to closed, brake fluid is drawn from the second wheel brake cylinder 14a into / allowed to be drawn into the increased at least one fluid containment volume 20c and 20d through at least one second valve 22b switched to at least partially open by means of the main electronic device 10a. This can also be described as follows: while the braking pressure in the first wheel brake cylinder 12a is locked by closing at least one first valve 22a, the braking pressure in the second wheel brake cylinder 14a is reduced / can be reduced by drawing brake fluid into at least one liquid containment volume 20c and 20d by means of the main electronic device 10a.

[0044] The secondary electronic device 10b of the control device 10 is designed and / or programmed such that, in the event of an electrical failure in the external braking system, the motor M or at least one first valve 22a and at least one second valve 22b are controlled / operable by means of the secondary electronic device 10b. The motor M of the electric piston cylinder device 20 is controlled / operable by means of at least one motor control signal 11b output by the secondary electronic device 10b, such that at least one linearly adjustable piston 20a and 20b of the electric piston cylinder device 20 are adjusted / adjustable by means of the controlled motor M, such that at least one liquid containment volume 20c and 20d (in their dimensions) of the electric piston cylinder device 20 limited by at least one piston 20a and 20b varies / can be varied.

[0045] First and second valves 22a and 22b, switchable by means of a secondary electronic device 10b, are arranged on the external braking system such that a first wheel brake cylinder 12a is hydraulically connected to at least one liquid reservoir volume 20c and 20d via at least one first valve 22a, and a second wheel brake cylinder 14a is hydraulically connected to at least one liquid reservoir volume 20c and 20d via at least one second valve 22b. At least one first valve 22a can be switched by means of at least one third valve switching signal 11e output by the secondary electronic device 10b. Correspondingly, at least one second valve 22b is switched by means of at least one fourth valve switching signal 11f output by the secondary electronic device 10b. Advantageous embodiments of the first and second valves 22a and 22b will be discussed subsequently.

[0046] Advantageously, the first and second valves 22a and 22b can be switched more quietly than the wheel exhaust valves 24a and 24b of the external braking system. In particular, at least one first wheel exhaust valve 24a downstream of the first wheel brake cylinder 12a and at least one second wheel exhaust valve 24b downstream of the second wheel brake cylinder 14a are controlled / held in their closed state while simultaneously performing the brake pressure holding or brake pressure increasing function for the first wheel brake cylinder 12a and the brake pressure decreasing function for the second wheel brake cylinder 14a.

[0047] Another advantage of the design / programming of the primary electronic device 10a and the secondary electronic device 10b is the use of an electric piston cylinder device 20 to reduce the braking pressure in the second wheel brake cylinder 14a. In the external braking system, especially in its "full-function mode," the vehicle driver is decoupled from the external braking system, so that the driver operating the brake control element / brake pedal (not shown) does not directly act on the hydraulic system of the external braking system. Instead, during the "full-function mode" of the external braking system, the driver performs the braking operation on a simulator (not shown). Therefore, the driver operating the brake control element / brake pedal does not feel the reaction force of reducing the braking pressure in the second wheel brake cylinder 14a using the electric piston cylinder device 20. The external braking system can be understood, in particular, as a braking system or brake-by-wire system decoupled from the driver.

[0048] exist Figure 1 In the braking system, the first switching valve 22a serves as the only first valve 22a, and the second switching valve 22b serves as the only second valve 22b. Therefore, by means of the advantageous design / programming of the main electronic device 10a and the secondary electronic device 10b, the switching valves 22a and 22b can be switched relatively quietly, especially compared to the wheel exhaust valves 24a and 24b.

[0049] Therefore, the primary electronic device 10a and the secondary electronic device 10b are designed and / or programmed such that, exactly if the second maximum braking pressure in the second wheel brake cylinder 14a is less than or equal to the first minimum braking pressure in the first wheel brake cylinder 12a, then, depending on the functional state of the external braking system, the primary electronic device 10a or the secondary electronic device 10b simultaneously performs / can perform the braking pressure holding or increasing function for the first wheel brake cylinder 12a and the braking pressure decreasing function for the second wheel brake cylinder 14a in the manner previously described. The primary electronic device 10a or the secondary electronic device 10b utilizes the fact that the check valve 22c of the first switching valve 22a, which is switched off, only opens when the second maximum braking pressure is greater than the first minimum braking pressure. (The check valve 22c of the first switching valve 22a is oriented such that brake fluid transmission from the first wheel brake cylinder 12a through the check valve 22c of the first switching valve 22a to the electric piston cylinder device 20 is prohibited.) The construction / programming of the main electronic device 10a and the secondary electronic device 10b described herein thus allows the use of the first switching valve 22a as a disconnect valve, although it is equipped with the check valve 22c.

[0050] As an advantageous improvement, the control device 10, its main electronic device 10a or its secondary electronic device 10b may be additionally designed and / or programmed to enable the simultaneous execution / performance of a braking pressure increase function for the first wheel brake cylinder 12a and a braking pressure decrease function for the second wheel brake cylinder 14a by means of the main electronic device 10a or the secondary electronic device 10b. This can be achieved in such a way that, while the transmission of brake fluid from the first wheel brake cylinder 12a to at least one fluid containment volume 20c and 20d increased by means of the controlled motor M is prohibited by means of at least one first valve 22a that has been switched to be closed, and brake fluid is drawn into / can be drawn into the increased fluid containment volume 20c and 20d from the second wheel brake cylinder 14a through at least one second valve 22b that has been switched to be at least partially open, at least one pump motor Mp of the external force braking system of at least one pump 26a and 26b is activated / can be activated by means of the main electronic device 10a or the secondary electronic device 10b, so that brake fluid can be pumped into / can be pumped into the first wheel brake cylinder 12a by means of at least one activated pump 26a. In particular, the primary electronic device 10a and the secondary electronic device 10b can be configured / programmed such that when the second maximum braking pressure in the second wheel brake cylinder 14a is less than or equal to the first minimum braking pressure in the first wheel brake cylinder 12a, the braking pressure increase function for the first wheel brake cylinder 12a and the braking pressure decrease function for the second wheel brake cylinder 14a are executed / enable together.

[0051] Therefore, the advantageous design / programming described in the preceding paragraphs using the primary electronics 10a and secondary electronics 10b allows for the use of the fact that the external braking system used to ensure good redundancy typically has not only the electric piston cylinder device 20 as its first regulator, but also at least one pump 26a and 26b as its second regulator. Additionally, the design / programming using the primary electronics 10a and secondary electronics 10b allows for the decoupling of the first wheel brake cylinder 12a, together with the correspondingly associated pump 26a, from the electric piston cylinder device 20 and the second wheel brake cylinder 14a via at least one first valve 22a switched to closed. During the closing / remaining closed period of at least one first valve 22a, brake fluid pumped into the first wheel brake cylinder 12a via at least one activated pump 26a can be drawn in through the first high-pressure switching valve 28a of the first brake circuit 16, which is switched to at least partially open. With the second high-pressure switching valve 28b of the second brake circuit 18 closed / remained closed, an undesirable increase in pressure in the second wheel brake cylinder 14a may be prevented by the pump 26b of the second brake circuit 18 driven by the pump motor MP being (essentially) blocked.

[0052] After reaching (close to) the target pressure of 0 bar or after reaching the atmospheric pressure in the first wheel brake cylinder 12a and / or the second wheel brake cylinder 14a, at least one downstream wheel exhaust valve 24a and 24b may be at least partially opened to compensate for possible leakage by at least one upstream wheel intake valve 30a and 30b.

[0053] For example only, Figure 1 The external braking system is constructed as a dual-box system. The first box 32a of the dual-box system includes an electrically operated piston cylinder device 20 and a brake fluid reservoir 34 hydraulically connected thereto. The second box 32b of the dual-box system has valves 22a, 22b, 24a, 24b, 28a, 28b, 30a, and 30b; at least one pump 26a and 26b; a storage chamber 36 downstream of the wheel exhaust valve 24a or 24b in each brake circuit 16 and 18; a check valve 38 arranged between the storage chamber 36 and the corresponding pump 26a or 26b; and a preload sensor 40 connected to the second brake circuit 18. However, the external braking system in… Figure 1 The components shown are to be interpreted illustratively only.

[0054] The braking pressure present in the first wheel brake cylinder 12a and the braking pressure present in the second wheel brake cylinder 14a, or the first maximum braking pressure, the first minimum braking pressure, the second maximum braking pressure, and / or the second minimum braking pressure, can be physical parameters estimated by the primary electronic device 10a and the secondary electronic device 10b. Alternatively or additionally, the primary electronic device 10a and the secondary electronic device 10b can also be designed / programmed to read the braking pressure present in the first wheel brake cylinder 12a and the braking pressure present in the second wheel brake cylinder 14a, or the first maximum braking pressure, the first minimum braking pressure, the second maximum braking pressure, and / or the second minimum braking pressure, from at least one sensor signal (e.g., in particular, the preload sensor 40 connected to the second brake circuit 18).

[0055] Figure 2 A flowchart illustrating an implementation method for a method of using an external braking system for operating a vehicle is shown.

[0056] Another description could be performed, for example, using one of the aforementioned external braking systems. However, the feasibility of this method is not limited to such an external braking system. Similarly, the feasibility of this method is not limited to a specific vehicle / motor vehicle type.

[0057] The method includes at least steps S1 to S3, which, through simultaneous execution, collectively achieve the functions of maintaining or increasing the braking pressure of the first wheel brake cylinder arranged on the vehicle axle for the external braking system, and decreasing the braking pressure of the second wheel brake cylinder arranged on the vehicle axle for the external braking system. In step S1, the motor of the electric piston cylinder device of the external braking system is controlled to increase at least one fluid-containing volume of the electric piston cylinder device by means of the controlled motor.

[0058] Meanwhile, in method step S2, at least one first valve of the external braking system is switched such that while the first wheel brake cylinder is hydraulically connected to at least one liquid containment volume via at least one first valve, the transmission of brake fluid from the first wheel brake cylinder to at least one liquid containment volume increased by means of the controlled motor is prohibited by means of at least one first valve that has been switched to be closed.

[0059] Similarly, in the simultaneously executed method step S3, at least one second valve of the external braking system is switched such that, while the second wheel brake cylinder is hydraulically connected to at least one liquid reservoir via at least one second valve, brake fluid is drawn from the second wheel brake cylinder into the increased at least one liquid reservoir through the at least one second valve that has been switched to at least partially open. Here, in the event of an electrical fault in the external braking system, the motor is controlled by a secondary electronic device, causing a change in at least one liquid reservoir of the electric piston cylinder device by means of the controlled motor, thereby performing a function of maintaining or increasing the brake pressure for the first and second wheel brake cylinders. Alternatively, in the event of an electrical fault in the external braking system, at least one first valve and at least one second valve are switched by a secondary electronic device, thereby performing a function of maintaining or increasing the brake pressure for the first and second wheel brake cylinders.

[0060] Examples of favorable conditions for at least one first valve and at least one second valve, as well as for performing method steps S1 to S3, have been described above.

[0061] Optionally, when performing the method described herein, the function of increasing the braking pressure for the first wheel brake cylinder and the function of decreasing the braking pressure for the second wheel brake cylinder can also be achieved simultaneously by the following measures: in addition to method steps S1 to S3, method step S4 is also performed. Simultaneously, during the process of brake fluid transfer from the first wheel brake cylinder to at least one increased fluid capacity volume via a controlled motor being prohibited by at least one first valve switched to closed and brake fluid being drawn from the second wheel brake cylinder into at least one increased fluid capacity volume via at least one second valve switched to at least partially open (method steps S1 to S3), the pump motor of at least one pump of the external braking system is additionally activated as method step S4, thereby pumping brake fluid into the first wheel brake cylinder by means of at least one activated pump.

[0062] Similarly, when performing the method described herein, a first brake pressure reduction function having a first rated gradient for the first wheel brake cylinder and a second brake pressure reduction function having a second rated gradient higher than the first rated gradient for the second wheel brake cylinder can also be simultaneously implemented. In method step S5, the motor of the electric piston cylinder device is operated such that at least one fluid containment volume of the electric piston cylinder device is reduced by means of the operated motor. Simultaneously, in method step S6, at least one second valve is switched to a state of at least partial opening. However, as part of method step S7, which is performed during the brake fluid transfer from the reduced at least one fluid containment volume to the second wheel brake cylinder via the at least one second valve switched to at least partial opening, implemented by method step S6, the brake fluid transfer from the reduced at least one fluid containment volume is interrupted multiple times via the at least one first valve switched to a state of short-term closure.

[0063] Furthermore, when performing the method described herein, a first brake pressure increase function having a first rated gradient for the first wheel brake cylinder and a second brake pressure increase function having a second rated gradient higher than the first rated gradient for the second wheel brake cylinder can be performed simultaneously. In method step S8, the motor is activated to enable brake fluid transfer from a reduced fluid containment volume by means of the controlled motor to the first and second wheel brake cylinders, wherein the first valve is controlled according to the first rated gradient.

[0064] Therefore, the implementation of the method described herein also provides the aforementioned advantages.

[0065] While the present invention has been exemplarily described above with reference to embodiments, it is not limited to these embodiments and can be modified in various ways. In particular, combinations of the above embodiments are also conceivable.

Claims

1. A control device (10) for an external braking system of a vehicle, comprising: A main electronic device (10a) is designed and / or programmed to enable the operation of a motor (M) of the electric piston cylinder device (20) of the external braking system, thereby allowing at least one liquid-containing volume (20c, 20d) of the electric piston cylinder device (20) to change by means of the operated motor (M), and at least one first valve (22a, 30a) and at least one second valve (22b, 30b) of the external braking system to be switched by means of the main electronic device (10a), wherein, The first wheel brake cylinder (12a) of the external braking system is hydraulically connected to the at least one liquid containment volume (20c, 20d) at least through the at least one first valve (22a, 30a), and the second wheel brake cylinder (14a) of the external braking system is hydraulically connected to the at least one liquid containment volume (20c, 20d) at least through the at least one second valve (22b, 30b). The main electronic device (10a) is designed and / or programmed to simultaneously perform a brake pressure holding or increasing function for the first wheel brake cylinder (12a) and a brake pressure decreasing function for the second wheel brake cylinder (14a) by means of the main electronic device (10a): at least during the period when brake fluid transfer from the first wheel brake cylinder (12a) to the at least one increased liquid containment volume (20c, 20d) by means of a controlled motor (M) is prohibited by means of at least one first valve (22a, 30a) switched to closed, brake fluid can be drawn from the second wheel brake cylinder (14a) into the increased at least one liquid containment volume (20c, 20d) through the at least one second valve (22b, 30b) switched to at least partially open; and Secondary electronic device (10b), said secondary electronic device being designed and / or programmed such that, in the event of an electrical fault in the external braking system, by means of said secondary electronic device (10b), either This enables the motor to be manipulated, thereby allowing at least one liquid-containing volume (20c, 20d) of the electric piston cylinder device (20) to change by means of the manipulated motor (M), thereby enabling the performance of a brake pressure holding or brake pressure increasing function for the first wheel brake cylinder (12a) and the second wheel brake cylinder (14a); or This allows the at least one first valve (22a, 30a) and the at least one second valve (22b, 30b) to be switched, thereby enabling the execution of a brake pressure maintenance or brake pressure increase function for the first wheel brake cylinder (12a) and the second wheel brake cylinder (14a).

2. The control device (10) according to claim 1, wherein, The electronic device (10a) is additionally designed and / or programmed such that it can simultaneously perform a braking pressure increase function for the first wheel brake cylinder (12a) and a braking pressure decrease function for the second wheel brake cylinder (14a) by means of the electronic device (10a) by means of the following measures: while the transmission of brake fluid from the first wheel brake cylinder (12a) to the at least one fluid containment volume (20c, 20d) increased by means of the controlled motor (M) is prohibited by means of at least one first valve (22a) switched to closed, and brake fluid can be drawn from the second wheel brake cylinder (14a) into the at least one fluid containment volume (20c, 20d) increased by means of the at least one second valve (22b) switched to at least partially open, the pump motor (MP) of at least one pump (26a, 26b) of the external braking system can additionally be activated by means of the electronic device (10a), so that brake fluid can be pumped into the first wheel brake cylinder (12a) by means of at least one activated pump (26a).

3. The control device (10) according to claim 1 or 2, wherein, The electronic device (10a) is additionally designed and / or programmed such that it can simultaneously perform a first brake pressure increase function with a first rated gradient for the first wheel brake cylinder (12a) and a second brake pressure increase function with a second rated gradient for the second wheel brake cylinder (14a) that is higher than the first rated gradient by means of the electronic device (10a) by means of the following measures: during the brake fluid transfer from the second wheel brake cylinder (14a) to the at least one fluid reservoir volume (20c, 20d) increased by means of the at least one fluid reservoir volume (20c, 20d) increased by means of the operated motor (M), the brake fluid transfer from the first wheel brake cylinder (12a) to the increased fluid reservoir volume (20c, 20d) is interrupted multiple times by means of the at least one first valve (22a, 30a) that is switched to short-term closure.

4. The control device (10) according to any one of the preceding claims, wherein, The main electronic device (10a) is additionally designed and / or programmed to enable simultaneous execution of a first brake pressure increase function with a first rated gradient for the first wheel brake cylinder (12a) and a second brake pressure increase function with a second rated gradient higher than the first rated gradient for the second wheel brake cylinder (14a) by means of the main electronic device (10a): the motor (M) can be activated to realize the transfer of brake fluid from the reduced liquid containment volume (20c, 20d) by means of the controlled motor (M) to the first wheel brake cylinder (12a) and the second wheel brake cylinder (14a), wherein the first valve (30a) is controlled according to the first rated gradient.

5. An external braking system for a vehicle, particularly an axle braking module, comprising: Control device (10) according to any one of the preceding claims; The electric piston cylinder device (20) has a motor (M) that can be controlled by means of the main electronic device (10a) and the secondary electronic device (10b) of the control device (10), so that the at least one liquid-containing volume (20c, 20d) of the electric piston cylinder device (20) can be changed by means of the controlled motor (M). A first wheel brake cylinder (12a) and a second wheel brake cylinder (14a) arranged or potentially arranged on the axle of the vehicle; and A first valve (22a, 30a) and a second valve (22b, 30b) are switchable by means of the main electronic device (10a) and the secondary electronic device (10b), wherein, The first wheel brake cylinder (12a) is hydraulically connected to the at least one liquid containment volume (20c, 20d) at least through the at least one first valve (22a, 30a), and the second wheel brake cylinder (14a) is hydraulically connected to the at least one liquid containment volume (20c, 20d) at least through the at least one second valve (22b, 30b).

6. The external force braking system according to claim 5, wherein, The control device is configured as the central controller of the vehicle.

7. The external braking system according to claim 5 or 6, wherein, The axle configuration is the rear axle of the vehicle, wherein the electric piston cylinder device (20), the at least one first valve (22a, 30a) and the at least one second valve (22b, 30b) are arranged on the rear axle.

8. A method for operating an external braking system for a vehicle, characterized in that, The braking pressure maintaining or increasing function of the first wheel brake cylinder (12a) arranged on the axle of the vehicle for the external braking system and the braking pressure decreasing function of the second wheel brake cylinder (14a) arranged on the axle of the vehicle for the external braking system are performed simultaneously by at least the following steps: The motor (M) of the electric piston cylinder device (20) of the external braking system is operated, thereby increasing (S1) the at least one liquid-containing volume (20c, 20d) of the electric piston cylinder device (20) by means of the operated motor (M). Switch at least one first valve (22a, 30a) of the external braking system such that, while the first wheel brake cylinder (12a) is hydraulically connected to the at least one liquid containment volume (20c, 20d) via at least the at least one first valve (22a, 30a), the transmission of brake fluid from the first wheel brake cylinder (12a) to the at least one liquid containment volume (20c, 20d) increased by means of the controlled motor (M) is prohibited by means of the at least one first valve (22a, 30a) that has been switched to closed (S2); and Switch at least one second valve (22b, 30b) of the external braking system such that, while the second wheel brake cylinder (14a) is hydraulically connected to the at least one liquid containment volume (20c, 20d) at least through the at least one second valve (22b, 30b), brake fluid is drawn from the second wheel brake cylinder (14a) through the at least one second valve (22b, 30b) which is switched to at least partially open (S3) into the increased at least one liquid containment volume (20c, 20d); In the event of an electrical fault in the external braking system, either by means of a secondary electronic device (10b) or Manipulating the motor (M) causes a change in the at least one liquid-containing volume (20c, 20d) of the electric piston cylinder device (20) via the manipulated motor (M), thereby performing a function of maintaining or increasing the braking pressure for the first wheel brake cylinder (12a) and the second wheel brake cylinder (14a); or Switching at least one first valve (22a, 30a) and at least one second valve (22b, 30b) performs a function of maintaining or increasing the brake pressure for the first wheel brake cylinder (12a) and the second wheel brake cylinder (14a).

9. The method according to claim 8, wherein, The braking pressure increase function for the first wheel brake cylinder (12a) and the braking pressure decrease function for the second wheel brake cylinder (14a) are performed simultaneously by the following measures: While the transmission of brake fluid from the first wheel brake cylinder (12a) to the at least one fluid containment volume (20c, 20d) increased by means of the controlled motor (M) is prohibited by means of the at least one first valve (22a) switched to closed, and brake fluid can be drawn from the second wheel brake cylinder (14a) into the increased at least one fluid containment volume (20c, 20d) through the at least one second valve (22b) switched to at least partially open, the pump motor (M) of at least one pump (26a, 26b) of the external braking system... P The brake fluid is additionally activated, causing the brake fluid to be pumped into the first wheel brake cylinder (12a) by means of at least one activated pump (26a).

10. The method according to claim 8 or 9, wherein, The first brake pressure reduction function having a first rated gradient for the first wheel brake cylinder (12a) and the second brake pressure reduction function having a second rated gradient for the second wheel brake cylinder (14a) higher than the first rated gradient are performed simultaneously by means of the following measures: during the transmission of brake fluid from the at least one liquid containment volume (20c, 20d) reduced by means of the operated motor (M) to the brake fluid in the second wheel brake cylinder (14a) through at least one second valve (22b, 3b) switched to at least partially open, the transmission of brake fluid from the at least one liquid containment volume (20c, 20d) is interrupted multiple times by means of the at least one first valve (22a, 30a) switched to short-term closed (S5-S7).

11. The method according to any one of claims 8 to 10, wherein, The first brake pressure increase function with a first rated gradient for the first wheel brake cylinder (12a) and the second brake pressure increase function with a second rated gradient higher than the first rated gradient for the second wheel brake cylinder (14a) are performed simultaneously by means of the following measures: the motor (M) is activated to realize the transfer of brake fluid from the reduced liquid containment volume (20c, 20d) by means of the controlled motor (M) to the first wheel brake cylinder (12a) and the second wheel brake cylinder (14a), wherein the first valve (30a) is controlled according to the first rated gradient (S8).

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