Method for operating mechanical mechanism in brake booster of brake system, and brake system

Abstract

The invention relates to a method for driving a mechanical mechanism in a brake booster device (10), comprising determining (S1) by means of a control device (SE) of a vehicle system (ESP) whether a driver braking expectation has ended or no driver braking expectation exists; detecting (S2) an operating failure of the brake booster device (10) by means of the control device (SE); detecting (S3) an operating failure of a pressure regulator, which is connected to the brake booster device (10) and is designed to form a brake pressure and / or a reset pressure at a master brake cylinder device (HZE) of the brake booster device (10), by means of the control device (SE); a predetermined minimum pressure is formed (S4) in the master brake cylinder device (HZE) by means of the vehicle system (ESP), and thus the mechanical mechanism and the master brake cylinder are reset into the neutral position by means of the mechanical mechanism.

Description

Technical Field

[0001] The invention relates to a method for driving a mechanical mechanism in a brake booster of a brake system and a brake system. Background Art

[0002] When a brake booster is used, a return spring can move the position of the master brake cylinder back to the neutral position after the braking process and thus reduce the brake pressure again. The return spring can be placed on the housing of the master brake cylinder and limit the movement path of the master brake cylinder in the direction of the brake pressure buildup. In other words, the piston of the brake cylinder can usually only be moved in the direction of the master brake cylinder until the compression of the return spring is completed.

[0003] Usually, the resetting of the transmission in the brake booster can be ensured by a single resetting spring for mechanical backup. The so-called backup can be a failure of the motor, for example in the event of a power failure at the motor, wherein the brake application position of the master brake cylinder can be released, wherein the resetting spring can take over the resetting movement of the master brake cylinder and the transmission unit, which would otherwise be moved by the motor for resetting.

[0004] Electromechanical pressure regulators and brake control systems (ESP) are known which together can form a brake system in a vehicle.

[0005] ESP has valves, circular storage chambers and pumps in order to enable wheel-specific pressure build-up and pressure reduction.

[0006] The main pressure regulator is located upstream of the ESP and acts on the piston of the (tandem) master brake cylinder (TMC) to build up pressure as a function of the braking request. The pressure regulator can also receive a braking request from the outside (control by wire).

[0007] When pressure builds up, the pressure regulator can also be operated in a regulated manner, but is additionally pressed back by the brake pressure and the return spring provided for this purpose.

[0008] A reset may always be necessary outside of a braking expectation until the sniffer hole in the TMC opens.

[0009] The return spring in the pressure regulator takes up a considerable amount of installation space and constantly resists the pressure build-up.

[0010] DE 10 2011 112 957 describes a braking device. Summary of the invention

[0011] The invention provides a method for driving a mechanical device in a brake booster of a brake system according to claim 1 and a brake system according to claim 9 .

[0012] Preferred developments are the subject matter of the dependent claims.

[0013] The present invention is based on the idea of ​​providing a method for driving a mechanical device in a brake booster and a brake system, wherein the function for resetting the mechanical device of the brake booster from a braking state can be achieved without a return spring.

[0014] The restoring force can be used to ensure a force for restoring the master brake cylinder and the electric motor drive unit, which can be used as an actuator for the master brake cylinder, and at the same time can reduce the force acting on the driver's foot in the fallback solution (brake solution).

[0015] According to the present invention, in a method for driving a mechanical mechanism in a brake booster of a brake system, a control device of a vehicle system is used to determine whether a driver's braking desire has ended after a preliminary braking process performed by the brake booster or whether there is no driver's braking desire at the brake booster after a preliminary braking process performed by the brake booster; an operational fault of the brake booster is identified by the control device; an operational fault of a pressure regulator is identified by the control device, the pressure regulator being connected to the brake booster or present therein and being configured to form a braking pressure and / or a reset pressure on a master brake cylinder device of the brake booster; a predetermined minimum pressure is formed in the master brake cylinder device by the vehicle system, and thereby, when the driver's braking desire ends or when there is no longer a driver's braking desire, the mechanical mechanism and, by means of the mechanical mechanism, the master brake cylinder are reset to a neutral position having a reduced braking effect or no braking effect on the brake element, wherein the formation of the minimum pressure is controlled by the control device of the vehicle system.

[0016] Operating faults can be faults in the grid / power supply, in the electronics / ECU / μC / ASIC, in the motor control or in the motor itself, or in the mechanics, which can be detected and can lead to a power outage.

[0017] The pressure regulator can be a component of a brake booster or a vehicle system. The pressure regulator according to the invention for a hydraulic series (wire-controlled) brake system can be a pressure / volume regulator, which can be operated in a pressure-regulated manner, and can be an ESP connected in series downstream thereof, which can also be operated in a pressure-regulated manner. The pressure-volume regulator can be a plunger system, for example the brake booster component (main actuator) itself, while the ESP can have a pump. For example, the pressure regulator can be the main actuator, while the ESP can be the backup actuator. The ESP (which can also be used as a pressure regulator) can detect the residual pressure in or on the master brake cylinder, then activate and push the master brake cylinder together with the mechanical mechanism of the brake booster back.

[0018] The neutral position can correspond to a position range of the master brake cylinder within which the braking force on the brake can be reduced or absent. When the brake is to be released, the master brake cylinder can therefore be displaced from the braking position into the neutral position by means of a return spring. The master brake cylinder can be connected to a further spring in the cylinder housing. The return spring can have a radius that is smaller than the radius of the cylinder housing, wherein the cylinder housing itself can have a cylindrical symmetry with respect to the main extension direction. The return pressure can be sufficient to displace the master brake cylinder into the neutral position.

[0019] A control device for a vehicle system, in particular a vehicle stability system (ESP), can have a function which advantageously has program instructions for controlling a pressure regulator of the vehicle (stabilization) system or of a brake booster and thus advantageously has a pump for delivering a hydraulic fluid volume. This function advantageously detects a failure of the pressure regulator or a failure of the pressure regulator during a braking process. By using valves, storage chambers and pumps in the ESP, this function in the ESP causes a volume flow in the direction of the master brake cylinder and takes over the resetting of the master brake cylinder piston. In a broader sense, the storage chamber can also be a wheel brake cylinder which can temporarily absorb more volume (and therefore pressure) than is required.

[0020] The mechanical system can include a transmission, an actuator, an electric motor and / or other components for moving the master brake cylinder.

[0021] According to a preferred embodiment of the method, an operational fault of the brake booster involves resetting the mechanism to a neutral position by the brake booster. The main actuator (as the pressure regulator of the brake booster itself) can be activated during all braking processes that require pressure buildup at all four wheels of the vehicle. This is, for example, the case of normal partial braking by the driver without brake control intervention. An operational fault can result in the actuator mechanism / motor no longer being able to return to the rest position with the open sniffer hole after the desired braking has ended, as a result of which an undesirable residual pressure can remain in the system.

[0022] According to a preferred embodiment of the method, a predetermined volume of hydraulic fluid is conducted from a storage chamber for hydraulic fluid by means of a pump into the master brake cylinder device by means of a vehicle system and a minimum pressure is thereby built up for resetting.

[0023] The storage chamber and the pump can be components of the vehicle system. The minimum pressure can be adaptively adapted or preset for the respective reset action (partial reset or complete reset).

[0024] According to a preferred embodiment of the method, the control device detects the current volume of hydraulic fluid in the storage chamber before the reset and compares it with the predetermined operating volume and, if the current volume is less than the predetermined operating volume, sucks additional volume from the front chamber of the master brake cylinder through the sealing lip of the master brake cylinder piston into the storage chamber by means of a pump and then pumps it from the storage chamber into the pressure region of the master brake cylinder in order to reach the minimum pressure. Calculated from the perspective of calculation, the volume inadvertently locked by the master brake cylinder is also just sufficient to push it back to the point where the master brake cylinder releases the sniffer hole again.

[0025] In the case of wheel brake cylinders, it can be that when negative pressure is present at the wheel brake cylinders, air is introduced into the brake circuit through the seals at the wheels. It can therefore be sensible to have a larger volume on the suction side of the pump than is mathematically required in order to push the piston of the master brake cylinder back at least to the position of the sniffer hole before negative pressure occurs at the wheels.

[0026] The predetermined operating quantity can be a quantity / volume of hydraulic fluid which, depending on the specification, can currently produce a braking effect or not produce a braking effect (eg reset).

[0027] For example, a minimum pressure can be built up in the pressure region by means of a pump for resetting.

[0028] According to a preferred embodiment of the method, after the additional volume has been at least partially pumped into the pressure region, this step is repeated at least once, whereby the current volume of the hydraulic fluid in the storage chamber before the reset is acquired and compared with the predetermined operating volume, and if the current volume is less than the predetermined operating volume, the additional volume is sucked from the antechamber of the master brake cylinder into the storage chamber by means of a pump through the sealing lip of the piston of the master brake cylinder and then pumped from the storage chamber into the pressure region of the master brake cylinder in order to achieve the minimum pressure. This repetition can be optional and is not mandatory. This function must always be activated when the ESP detects an undesirable residual pressure.

[0029] According to a preferred embodiment of the method, the control device detects the presence of a driver's braking desire via a pedal position and / or via detection of the vehicle speed and / or via a driver interface.

[0030] According to a preferred embodiment of the method, the control device is a control device of a vehicle stabilization system.

[0031] According to a preferred embodiment of the method, the minimum pressure is sufficient to open the sniffer opening when the master brake cylinder is reset.

[0032] The ESP is advantageously able to detect whether there are malfunctions in the pressure regulator and / or the brake booster.

[0033] This identification can advantageously be achieved by known mechanisms, such as network monitoring or the transmission and identification of electrical signals from the pressure regulator and / or the brake booster.

[0034] For this purpose, the ESP can advantageously check whether a braking request is present, which can be accomplished via an interface, for example a signal interface in the vehicle and / or in the ESP.

[0035] If there is a braking desire, the task of ESP can be to build up a certain pressure on the wheel (brake on the wheel) as an alternative regulator for the brake booster. This function can be activated when there is no braking desire but it cannot be ruled out that there may still be residual pressure in the brake system and / or in ESP.

[0036] The function on the ESP can be activated and a volume (of hydraulic fluid) can then be delivered in the direction of the master brake cylinder (eg tandem master brake cylinder TMC) in order to build up a pressure against the master brake cylinder piston if the sniffer hole has not yet opened.

[0037] If there is too little volume in the ESP, the ESP can first suck in volume through the sealing lip of the master brake cylinder with the help of a pump, which can act like a check valve. The HSV (high-pressure switching valve) enables the ESP to draw volume from the TMC / reservoir after opening and is open here and closes the USV (the switching valve enables the ESP to direct the volume sucked out of the reservoir to the wheels or keep it at the wheels and / or the storage chamber). The EV and AV can also be opened, but not at the same time. Closing the inlet valve (EV) to the wheel can prevent further pressure buildup at the wheel (usually in ABS brakes).

[0038] In this case, the EV can be switched on and the AV can be switched off, wherein the pump can then bring the volume to the wheels.

[0039] It is possible that the EV is closed, the AV is open, and the volume then flows automatically into the reservoir chamber, or that the pump sucks the volume out of the reservoir chamber and delivers it to the master brake cylinder, since the AV can be closed and the USV can be open.

[0040] When the outlet valves (AV) are closed and opened, they also allow the wheel volume to flow into the storage chamber or to the pump. The valves can be connected one behind the other.

[0041] First, the pump can deliver volume to the wheels via the opened EV. Then the pump can be deactivated, the EV closed and the AV opened. At this point, the pump delivers volume from the wheels and the reservoir in the direction of the TMC.

[0042] The volume can advantageously be controlled by using a model (programmed instructions as a function in the control device) which is aware of the measured pressures and the history of the pump and valve activities.

[0043] Specific volumes can be temporarily stored in storage chambers.

[0044] If the storage chamber is at least partially filled, the ESP can start to transfer volume back to the master brake cylinder. For this purpose, the HSV and the EV can be closed in order to transfer volume from the storage chamber in the direction of the ESP. For the period of time that the sniffer hole of the master brake cylinder arrangement is closed, a pressure can be built up which resets the piston and the mechanism downstream thereof together with the motor for the mechanism. One or more of the previous steps can be repeated as required (for example, if the volume in the storage chamber is too low) to ensure that the sniffer hole is open.

[0045] The method according to the invention can be used in a braking system consisting of an ESP and an upstream pressure regulator. A prerequisite can be that the ESP is able to determine that the residual pressure does not simultaneously represent a braking requirement. This is the case, for example, with decoupled brake-by-wire systems.

[0046] According to the present invention, a brake system comprises a brake booster device and a control device of a vehicle system, wherein the brake booster device is connected to the control device and can be connected to a pressure regulator or comprises the pressure regulator, wherein the control device is configured to detect whether a driver's braking desire ends after a pre-braking process performed by the brake booster device or whether the driver's braking desire does not exist at the brake booster device after a pre-braking process performed by the brake booster device; to identify whether an operating fault exists in the brake booster device; to identify whether an operating fault exists in the pressure regulator, wherein the pressure regulator is connected to the brake booster device or is comprised by it and is configured to form a braking pressure and / or a reset pressure on a master brake cylinder device of the brake booster device; a predetermined minimum pressure is formed in the master brake cylinder device by the vehicle system, and thereby, when the driver's braking desire ends or when the driver's braking desire no longer exists, a mechanical mechanism and, by means of the mechanical mechanism, the master brake cylinder is reset to a neutral position, which has a reduced braking effect or no braking effect on the brake element, wherein the formation of the minimum pressure can be controlled by the control device of the vehicle system.

[0047] According to a preferred embodiment of the brake system, the control device comprises a control device of a vehicle stabilization system.

[0048] The braking system can also be distinguished by the features mentioned in connection with the method and the advantages thereof, and vice versa.

[0049] Further features and advantages of embodiments of the present invention will be apparent from the following description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The present invention will be described in detail below based on the embodiments given in the schematic diagrams of the accompanying drawings.

[0051] in:

[0052] Figure 1 A schematic diagram showing a braking system according to an embodiment of the present invention is shown;

[0053] Figure 2 A block diagram of method steps of a method for driving a mechanical mechanism in a brake booster device in a brake system according to an embodiment of the present invention is shown.

[0054] In the figures, the same reference signs denote identical or functionally identical elements. DETAILED DESCRIPTION

[0055] Figure 1 A schematic diagram of a brake system according to an embodiment of the present invention is shown.

[0056] The present invention shows a brake system 1 having a brake booster 10 and a control device SE of a vehicle system ESP, wherein the brake booster 10 is connected to the control device SE and can be connected to a pressure regulator or comprises a pressure regulator (which can be referred to as the brake booster 10 or the ESP or another pressure regulator), wherein the control device SE is configured to detect, by means of the control device SE, whether a driver's braking desire has ended after a pre-braking process by the brake booster 10 or whether there is no driver's braking desire at the brake booster 10 after a pre-braking process by the brake booster 10; and to detect whether there is a brake booster 10. 10; for identifying whether there is an operational fault of a pressure regulator, wherein the pressure regulator is connected to the brake booster and is designed to build up a braking pressure and / or a reset pressure on a master brake cylinder device HZE of the brake booster 10; and for building up a predetermined minimum pressure in the master brake cylinder device HZE by means of the vehicle system ESP, and thereby, when the driver's braking desire ends or when the driver's braking desire no longer exists, causing the mechanical mechanism and, via the mechanical mechanism, the master brake cylinder to be reset to a neutral position, which has a reduced braking effect or no braking effect on the brake element, wherein the building up of the minimum pressure can be controlled by a control device of the vehicle system.

[0057] ESP a detects a failure of the pressure regulator b. This can be achieved, for example, by known mechanisms such as network monitoring g or electrical signals g. ESP a can check whether there is a braking desire. This can be achieved through a signal interface, for example, using a control device SE. If there is a braking desire, ESP can have the task of forming pressure in the wheel as an alternative regulator for the brake booster. This function can be activated when there is no braking desire but it cannot be ruled out that there is still residual pressure in the system. When the sniffer hole (Schnüffelbohrung) is not opened, the ESP function can be activated and the purpose is to deliver volume (Volumen) in the direction of TMC (HZE, f) in order to form a pressure against the TMC piston. If the volume present in the ESP is too small, it first sucks the volume through the sealing lip of the TMC with the help of a pump e, and the sealing lip acts like a check valve.

[0058] In this case, HSV h is open and USV i is closed. EV j and AV k are also open. Volume balancing can be achieved by means of a model that knows the measured pressure and the history of pump e and valve activity (h, i, j, k). The volume is stored temporarily in the storage chamber d. If the storage chamber d is at least partially filled, the ESP starts to transport the volume back in the direction of TMC f. For this purpose, HSV h and EV j are closed in order to transport the volume from the storage chamber in the direction of the ESP. As long as the sniffer hole is closed, a pressure is built up that resets the piston and its downstream mechanical mechanism together with the motor.

[0059] Figure 2 A block diagram of method steps of a method for actuating a mechanical device in a brake booster device in a brake system according to an exemplary embodiment of the present invention is shown.

[0060] In a method for driving a mechanical mechanism in a brake booster of a brake system, a control device of a vehicle system is used to detect S1 whether a driver's braking desire has ended after a preliminary braking process by the brake booster or whether there is no driver's braking desire at the brake booster after a preliminary braking process by the brake booster; an operational fault of the brake booster is detected S2 by the control device; an operational fault of a pressure regulator is detected S3 by the control device, which is connected to the brake booster and is designed to form a braking pressure and / or a reset pressure on a master brake cylinder device of the brake booster; a predetermined minimum pressure is formed (Aufbauen) S4 in the master brake cylinder device by the vehicle system, and thereby the mechanical mechanism and the master brake cylinder are reset to a neutral position with a reduced braking effect or no braking effect on the brake element when the driver's braking desire ends or no longer exists, wherein the formation of the minimum pressure is controlled by the control device of the vehicle system.

[0061] Although the invention has been fully described above on the basis of preferred exemplary embodiments, it is not restricted thereto but can be modified in many ways.

Claims

1. A method for driving a mechanical mechanism in a brake force amplification device (10) in a brake system (1), comprising the following steps: - detecting (S1) by means of a control device (SE) of a vehicle system (ESP) whether a driver's braking desire has ended after a preliminary braking process by a brake booster (10) or whether a driver's braking desire is no longer present at the brake booster (10) after a preliminary braking process by a brake booster (10); - detecting (S2) an operating fault of the brake booster (10) by means of a control device (SE); - detecting (S3) an operating fault of a pressure regulator by means of a control device (SE), said pressure regulator being connected to or included in the brake booster device (10) and being designed to build up a brake pressure and / or a reset pressure at a master brake cylinder device (HZE) of the brake booster device (10); - A predetermined minimum pressure is generated (S4) in the master brake cylinder device (HZE) by the vehicle system (ESP), and thereby, when the driver's braking desire ends or when the driver's braking desire no longer exists, the mechanical mechanism and, via the mechanical mechanism, the master brake cylinder are reset to a neutral position having a reduced braking action or no braking action on the brake element, wherein the generation of the minimum pressure is controlled by a control device (SE) of the vehicle system (ESP).

2. The method according to claim 1, wherein: An operational fault of the brake booster (10) involves resetting a mechanical mechanism into a neutral position by the brake booster (10).

3. The method according to claim 1 or 2, wherein: By means of the vehicle system (ESP), a predetermined volume of hydraulic fluid is conducted from a storage chamber for hydraulic fluid by means of a pump into the master brake cylinder arrangement (HZE), thereby building up a minimum pressure for resetting.

4. The method according to claim 3, wherein: The control device (SE) detects the current volume of the hydraulic fluid in the storage chamber before resetting and compares it with the predetermined operating volume. If the current volume is less than the predetermined operating volume, the additional volume is sucked into the storage chamber from the front chamber of the master brake cylinder through the sealing lip of the piston of the master brake cylinder by the pump and then pumped from the storage chamber into the pressure area of ​​the master brake cylinder to reach the minimum pressure.

5. The method according to claim 4, wherein: After the additional volume has been at least partially pumped into the pressure area, this step is repeated at least once, whereby the current volume of the hydraulic fluid in the storage chamber before resetting is acquired and compared with the predetermined operating volume, and if the current volume is less than the predetermined operating volume, the additional volume is sucked into the storage chamber from the antechamber of the master brake cylinder through the sealing lip by the pump and then pumped from the storage chamber into the pressure area of ​​the master brake cylinder in order to reach the minimum pressure.

6. The method according to any one of claims 1 to 5, wherein: The control device (SE) detects the presence of a driver's braking request via a pedal position and / or via detection of the vehicle speed and / or via a driver interface.

7. The method according to any one of claims 1 to 6, wherein: The control device is a control device of a vehicle stability system.

8. The method according to any one of claims 1 to 7, wherein: The minimum pressure is sufficient to open the sniffer opening when the master brake cylinder is reset.

9. A brake system (1) comprising a brake booster (10) and a control device (SE) of a vehicle system (ESP), wherein: The brake booster (10) is connected to a control device (SE) and can be connected to a pressure regulator or includes a pressure regulator, wherein the control device (SE) is configured to determine, by means of the control device (SE), whether the driver's braking desire has ended after a pre-braking process performed by the brake booster (10) or whether the driver's braking desire does not exist at the brake booster (10) after a pre-braking process performed by the brake booster (10); to identify whether the brake booster (10) has an operating fault; and to identify whether the pressure regulator has an operating fault, wherein the pressure regulator The regulator is connected to or included in the brake booster and is designed to generate a brake pressure and / or a reset pressure at a master brake cylinder device (HZE) of the brake booster (10); and to generate a predetermined minimum pressure in the master brake cylinder device (HZE) via a vehicle system (ESP), and thereby to reset the master brake cylinder to a neutral position, which has a reduced braking effect or no braking effect on the brake element, when the driver's braking desire ends or when the driver's braking desire no longer exists, by means of the mechanical mechanism. The formation of the minimum pressure can be controlled by a control device of the vehicle system.

10. The brake system (1) according to claim 9, wherein: The control device (SE) comprises a control device (SE) of a vehicle stabilization system.

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