A method for actuating a mechanism in a brake booster device of a braking system, and a braking system

Abstract

The present invention provides a method for actuating a mechanism in a brake booster device (10), the method comprising: a determination (S1) by a control device (SE) of a vehicle system (ESP) as to whether the driver's braking request has ended or whether there is no driver's braking request; a recognition (S2) by the control device (SE) of an operating failure of the brake booster device (10); a recognition (S3) by the control device (SE) of an operating failure of a pressure controller set up to generate a brake pressure and / or a return pressure in a master brake cylinder device (HZE) of the brake booster device (10), which is connected to the brake booster device (10); and a generation (S4) by the vehicle system (ESP) of a pre-determined minimum pressure in the master brake cylinder device (HZE), whereby a return of the mechanism to the neutral position and thereby of the master brake cylinder is effected.

Description

Technical Field

[0001] The present invention relates to a method for actuating a mechanism in a brake booster device of a braking system and to a braking system.

Background Art

[0002] When a brake booster device is used, a return spring can slide to return the position of the master brake cylinder to the neutral position again after the braking process, and accordingly, the brake pressure can be reduced again. The return spring can be mounted on the housing of the master brake cylinder, and the movement stroke of the master brake cylinder in the direction in which the brake pressure is generated can be restricted. In other words, the piston of the brake cylinder can usually be displaced in the direction of the master brake cylinder only as long as the return spring is being compressed.

[0003] Normally, the return of the transmission device in a brake booster can be ensured through a single return spring for mechanical backup. At this time, the so-called backup can be targeted at a failure of the motor such as when the energization of the motor stops, and the return spring can bear the return movement of the master brake cylinder and the transmission device unit that should originally be moved by the motor for return, so that the braking action position of the master brake cylinder can be eliminated.

[0004] An electromechanical pressure regulator and a brake control system (ESP) that can jointly form a vehicle's braking system are known.

[0005] The ESP includes a valve, a circular storage chamber, and a pump in order to enable individual wheel pressure generation and pressure reduction.

[0006] The primary pressure regulator is placed upstream of the ESP and acts on the piston of the (tandem type) master brake cylinder (TMC) to generate pressure according to the braking demand. The pressure regulator can also receive the braking demand externally (two-wire).

[0007] During pressure generation, the pressure regulator can also be controlled and operated, but is additionally pushed back by the brake pressure and by the return spring provided therefor.

[0008] It may always be necessary to effect a return outside the braking demand range until the orifice hole in the TMC is opened.

[0009] The return spring of the pressure regulator occupies a considerable design space and always acts in the opposite direction to pressure generation.

[0010] Patent Document 1 describes a braking device.

Prior Art Document

Patent Document

[0011]

Patent Document 1

Summary of the Invention

[0012] The present invention provides a method for actuating a mechanism in a brake booster device of a braking system as described in claim 1, and a braking system as described in claim 9.

[0013] Preferred developments are the subject of the dependent claims.

[0014] The idea underlying the present invention is to provide a method for actuating a mechanism in a brake booster device and a braking system, in which the function for the return of the mechanism of the brake booster device from the braking state can be realized without a return spring.

[0015] The force for returning the master brake cylinder and the transmission device unit for an electric motor that can serve as an actuator of the master brake cylinder can be ensured by the restoring force, and at the same time, the force acting against the driver's foot during backup (brake release) can be reduced.

[0016] According to the present invention, in a method of actuating a mechanism in a brake booster device of a braking system, it is determined by a control device of a vehicle system whether a driver's braking request has ended after a preceding braking process by the brake booster device, or whether a driver's braking request does not exist in the brake booster device after a preceding braking process by the brake booster device; recognition of an operation failure of the brake booster device is performed by the control device; recognition of an operation failure of a pressure controller set up to generate a brake pressure and / or a return pressure in a master brake cylinder device of the brake booster device, which is connected to or present in the brake booster device, is performed by the control device; when the driver's braking request has ended or when the driver's braking request no longer exists, generation of a predetermined minimum pressure in the master brake cylinder device is performed by the vehicle system, whereby the braking action on the brake member is reduced or the mechanism returns to a neutral position without a braking action, and thereby the master brake cylinder returns, and the generation of the minimum pressure is controlled by the control device of the vehicle system.

[0017] An operation failure refers to an error in an electrical vehicle network / supply unit, electronics / ECU / μC / ASIC, an error in a motor control unit or the motor itself, or an error in a mechanism, which can be recognized and lead to a stop.

[0018] The pressure controller may be a component of a brake booster device or a vehicle system. The pressure controller for a hydraulic in-line (by-wire) brake system according to the present invention may be a pressure / volume regulator that can be operated in a pressure-controlled manner, and an ESP arranged in series behind it that can also be operated in a pressure-controlled manner. The pressure / volume regulator may be a plunger system, for example, the brake booster component (primary actuator) itself, while the ESP may have a pump. For example, the pressure regulator may be the primary actuator, and the ESP may be the backup actuator. (The ESP that can also function as a pressure controller) can determine the residual pressure inside or on the surface of the master brake cylinder, and subsequently become active to return-slide the master brake cylinder including the mechanism of the brake booster.

[0019] The neutral position may correspond to a region of the position of the master brake cylinder where the braking force on the brake can be reduced or does not exist. That is, when the brake is to be released, the return spring can slide the master brake cylinder from the brake position to the neutral position. The master brake cylinder may be coupled to another spring in the cylinder housing. The return spring can include a radius smaller than the radius of the cylinder housing, and the cylinder housing itself can have cylinder symmetry relative to the main elongation direction. The return pressure may be sufficient to slide the master brake cylinder to the neutral position.

[0020] The control device of a vehicle system, in particular of a vehicle stability system (ESP), can preferably have a function with program commands for controlling the pressure regulator of this vehicle (stability) system, or the pressure controller of a brake booster device, and preferably also a pump for transferring the volume of the working fluid associated therewith. This function preferably recognizes a defect in the pressure controller or pressure regulator during the braking process. By using the ESP valve, the storage chamber, and the pump, this function in the ESP causes a volume flow in the direction of the master brake cylinder and is responsible for the return of the piston of the master brake cylinder. The storage chamber can, in a broad sense, also be a wheel brake cylinder that can temporarily receive a volume (and associated pressure) that is more than necessary.

[0021] The mechanism can include a transmission, an actuator device, an electric motor, and / or other components for moving the master brake cylinder.

[0022] In a preferred embodiment of the method, the malfunction of the brake booster device is targeted at the return of the mechanism to the neutral position by the brake booster device. The primary actuator (the pressure regulator as the brake force device itself) can become active during any braking that requires pressure generation at all four wheels of the vehicle, for example during normal partial braking by the driver without brake control intervention. If a malfunction occurs at that time, it can lead to the inability to return the actuator mechanism / motor to the rest position where the orifice hole is open after the end of the braking desire, and for this reason, unintended residual pressure can remain in the system.

[0023] In a preferred embodiment of the method, for return by the vehicle system, a pre-determined volume of the working fluid is guided by a pump from the storage chamber of the working fluid to the master brake cylinder device, thereby generating a minimum pressure.

[0024] The storage chamber and the pump may be components of a vehicle system. The minimum pressure can be adaptively adapted for each return action (partial or full return), or may be set.

[0025] In a preferred embodiment of the method, by means of a control device, the volume of the hydraulic fluid present in the storage chamber before the return is determined and compared with a predetermined operating quantity. If the volume present is less than the predetermined operating quantity, an additional volume for reaching the minimum pressure through the pump is sucked from the pre-chamber of the master brake cylinder into the storage chamber via the seal lip of the piston of the master brake cylinder, and subsequently pumped from the storage chamber into the pressure region of the master brake cylinder. In terms of calculation, the amount of volume unintentionally trapped by the master brake cylinder is just sufficient to return-slide it to the extent that the master brake cylinder reopens the orifice hole.

[0026] In the wheel brake cylinder, when a negative pressure occurs in the wheel brake cylinder, air may enter the brake circuit through the wheel seal material. Therefore, it may be meaningful to have a volume on the suction side of the pump that is more than computationally necessary to push back the piston of the master brake cylinder at least to the position of the orifice hole before a negative pressure occurs in the wheel.

[0027] The predetermined operating quantity may be the amount / volume of the hydraulic fluid that, depending on the setting, can currently generate a braking action or cannot generate a braking action (e.g., return).

[0028] The minimum pressure can be generated in the pressure region for return, for example, by means of a pump.

[0029] In a preferred embodiment of the method, this step is repeated only at least once after the additional volume has been at least partially pumped into the pressure region, and then the volume of the working fluid present in the storage chamber is determined and compared with a predetermined operating volume before the return. If the volume present is less than the predetermined operating volume, an additional volume to reach the minimum pressure through the pump is sucked from the pre-chamber of the master brake cylinder into the storage chamber through the seal lip of the piston of the master brake cylinder and subsequently pumped from the storage chamber into the pressure region of the master brake cylinder. This repetition may be optional and does not necessarily have to be introduced. This function must always be initiated when the ESP detects an unintentionally remaining residual pressure.

[0030] In a preferred embodiment of the method, the control device recognizes the presence of the driver's braking desire through the pedal position and / or through the determination of the vehicle speed and / or through the driver interface.

[0031] In a preferred embodiment of the method, the control device is the control device of the vehicle stability system.

[0032] In a preferred embodiment of the method, the minimum pressure is sufficient to open the orifice hole when the master brake cylinder returns.

[0033] Preferably, the ESP can recognize whether an operating failure of the pressure controller and / or the brake booster device has occurred.

[0034] Such recognition can preferably be carried out through well-known mechanisms such as network monitoring or recognition of electrical signals from the pressure controller and / or the brake booster device.

[0035] For this purpose, it is preferably possible for the ESP to check whether there is a braking request, which may be possible via an interface, for example via the vehicle and / or the signal interface of the ESP.

[0036] In the case where there is a braking request, the role of the ESP may be to generate a specific pressure at the wheel (braking at the wheel) as an alternative regulator for the brake booster. Such a function can also be activated if there is no braking request but the possibility that residual pressure still exists in the brake system and / or the ESP cannot be excluded.

[0037] If the orifice hole has not yet been opened, in order to generate pressure on the piston of the master brake cylinder, the function in the ESP can be activated to send the volume (of the working fluid) in the direction of the master brake cylinder (for example, a tandem master brake cylinder TMC).

[0038] In the case where the volume existing in the ESP is too small, the ESP can first suck in the volume via the seal lip of the master brake cylinder, which can act like a check valve, by means of a pump. The HSV (high-pressure switching valve) enables the ESP to suck in the volume from the TMC / reservoir after opening, and is open at that time, while the USV is closed (this switching valve enables the ESP to guide the volume sucked in from the reservoir to the wheel or to keep it in the wheel and / or the storage chamber). The EV and AV can also be open, but not simultaneously. The intake valve (EV) closed towards the wheel can prevent further pressure generation at the wheel (typically in the case of ABS braking).

[0039] In that case, it is possible that the EV is open and the AV is closed, in which case the pump can send the volume to the wheel.

[0040] The EV can be closed and the AV can be open, and the volume automatically flows into the storage chamber, or the pump draws volume from the storage chamber and delivers it to the master brake cylinder, since the AV can be closed and the USV can be open.

[0041] They also allow the wheel volume to flow into the storage chamber or towards the pump when the exhaust valve (AV) is closed and when it is open. These valves can be switched sequentially. First, the pump can deliver volume to the wheels through the open EV. Then the pump can be stopped, the EV closed and the AV opened. The pump then delivers volume from the wheels and the storage chamber towards the TMC.

[0042] Volume control is preferably achieved through the use of models (as programmed instructions of the function in the controller) that know the measured pressure and pump history as well as valve operation.

[0043] A certain volume can be intermediately stored in a storage chamber.

[0044] When the storage chamber is at least partially filled, the ESP can start to send the volume back to the master brake cylinder. For this purpose, the HSV and EV can be closed to send the volume from the storage chamber in the direction of the ESP. During the time period when the orifice hole of the master brake cylinder device is closed, a pressure can be generated that returns the piston and the mechanism that follows it by means of a motor for the mechanism. If necessary (e.g. due to too little volume from the storage chamber), one or more of the preceding steps can be repeated to ensure the opening of the orifice hole.

[0045] The method according to the invention can be applied in a braking system composed of an ESP and a pressure regulator preposed thereto. It may be a prerequisite that the ESP can determine that the residual pressure is not simultaneously desired for braking. This applies, for example, when the brake-by-wire system is disengaged.

[0046] According to the invention, the braking system includes a brake booster device and a control device of the vehicle system. The brake booster device is connected to the control device and can be connected to a pressure controller or includes a pressure controller. The control device determines whether the driver's braking demand has ended after a previous braking process by the brake booster device, or whether the driver's braking demand no longer exists in the brake booster device after a previous braking process by the brake booster device; recognizes whether there is an operating failure in the brake booster device; and is set up to recognize whether there is an operating failure in the pressure controller. The pressure controller is connected to or included in the brake booster device, generates a braking pressure and / or a return pressure in the master brake cylinder device of the brake booster device; and when the driver's braking demand has ended or no longer exists, generates a pre-determined minimum pressure by the vehicle system in the master brake cylinder device, thereby reducing the braking action on the brake member or causing the mechanism to return to a neutral position where there is no braking action and, thereby, causing the return of the master brake cylinder. The generation of the minimum pressure is controllable by the control device of the vehicle system.

[0047] In a preferred embodiment of the braking system, the control device includes the control device of the vehicle stability system.

[0048] The braking system is characterized by each component described in connection with the method and its advantages, and vice versa.

[0049] Other components and advantages of the embodiments of the present invention will become apparent from the following description with reference to the accompanying drawings.

[0050] Next, the present invention will be described in detail with reference to the embodiments shown in the schematic diagrams of the drawings.

Brief Description of the Drawings

[0051]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0052] In each figure, the same reference numerals represent the same members or members having the same functions.

[0053] FIG. 1 shows a schematic diagram of a braking system according to an embodiment of the present invention.

[0054] A braking system 1 having a brake booster device 10 and a control device SE of a vehicle system ESP is illustrated. The brake booster device 10 is connected to the control device SE and can be connected to a pressure controller or includes a pressure controller (here, the brake booster device 10 or ESP or another pressure controller may be meant). The control device SE determines whether the driver's braking request has ended after a preceding braking process by the brake booster device 10, or whether the driver's braking request does not exist in the brake booster device 10 after a preceding braking process by the brake booster device 10; recognizes whether there is an operating failure of the brake booster device 10; and is set up to recognize whether there is an operating failure of the pressure controller. The pressure controller is connected to the brake booster device and generates a brake pressure and / or a return pressure in the master brake cylinder device HZE of the brake booster device 10. When the driver's braking request has ended or when the driver's braking request no longer exists, a pre-determined minimum pressure is generated in the master brake cylinder device HZE by the vehicle system ESP, thereby reducing the braking action on the brake member or causing the mechanism to return to a neutral position without a braking action, and thereby causing the return of the master brake cylinder. The generation of the minimum pressure is controllable by the control device of the vehicle system.

[0055] The ESPa recognizes the failure of the pressure regulator b. This can be done, for example, through known mechanisms such as network monitoring g or an electrical signal g. The ESPa can check whether a braking request is present. This is possible, for example, through a signal interface with the control device SE. If a braking request is present, the ESP can take on the role of generating pressure at the wheels as a substitute regulator for the brake booster. This function can be activated if there is no braking request, but it cannot be excluded that there is still residual pressure in the system. An ESP function can be activated, which has the purpose of sending a volume in the direction TMC(HZE,f) if the orifice hole is not yet open, in order to generate pressure against the TMC piston. If there is too little volume in the ESP, the ESP first sucks the volume in by means of the pump e through the sealing lip of the TMC, which acts like a non-return valve.

[0056] At this time, HSVh is opened and USVi is closed. EVsj and AVsk are also opened. Volume management can be performed via a model that knows the measured pressure and the history of the pump e and valve operation (h, i, j, k). The volume is stored intermediately in the storage chamber d. When the storage chamber d is at least partially filled, the ESP starts to return the volume in the direction TMCf. For this purpose, HSVh and EVsj are closed, sending the volume from the storage chamber in the direction ESP. As long as the orifice hole is closed, a pressure is generated that resets the piston and the mechanism behind it by the motor.

[0057] FIG. 2 shows a block diagram of method steps of a method for activating a mechanism in a brake booster device of a braking system according to an embodiment of the invention.

[0058] In a method of actuating a mechanism in a brake booster device of a braking system, a determination S1 is made by a control device of the vehicle system as to whether a driver's braking request has ended after a preceding braking process by the brake booster device, or whether a driver's braking request does not exist in the brake booster device after a preceding braking process by the brake booster device; a recognition S2 of an operating failure of the brake booster device is made by the control device; a recognition S3 of an operating failure of a pressure controller set up to generate a brake pressure and / or a return pressure in a master brake cylinder device of the brake booster device, which is connected to the brake booster device, is made by the control device; when the driver's braking request has ended or when the driver's braking request no longer exists, a generation S4 of a pre-determined minimum pressure is performed by the vehicle system in the master brake cylinder device, whereby the braking action on the brake member is reduced or the mechanism returns to a neutral position where there is no braking action, and the generation of the minimum pressure is controlled by the control device of the vehicle system.

[0059] Although the present invention has been fully described above with reference to preferred embodiments, the present invention is not limited thereto and can be modified in various forms.

Explanation of Reference Numerals

[0060] 1 Braking system 10 Brake booster device ESP Vehicle system SE Control device HZE Master brake cylinder device S1 Determination S2 Recognition S3 Recognition S4 Generation

Claims

1. A method of activating a mechanism in a brake booster device (10) of a brake system (1), comprising the following steps: Determination (S1) by a control device (SE) of a vehicle system (ESP) as to whether a driver's braking request has ended after a previous braking process by the brake booster device (10), or whether a driver's braking request does not exist in the brake booster device (10) after a previous braking process by the brake booster device (10); Recognition (S2) by the control device (SE) of an operating failure of the brake booster device (10); Recognition (S3) by the control device (SE) of an operating failure of a pressure controller set up to generate a brake pressure and / or a return pressure in a master brake cylinder device (HZE) of the brake booster device (10) that is connected to or included in the brake booster device (10); Generation (S4) by the vehicle system (ESP) of a pre-determined minimum pressure in the master brake cylinder device (HZE) when a driver's braking request has ended or when a driver's braking request no longer exists, whereby the braking action on the brake member is reduced or the mechanism and thereby the master brake cylinder is returned to a neutral position with no braking action, the generation of the minimum pressure being controlled by the control device (SE) of the vehicle system (ESP).

2. The method according to claim 1, wherein the operating failure of the brake booster device (10) targets the return of the mechanism to a neutral position by the brake booster device (10).

3. The method according to claim 1 or 2, wherein for the return by the vehicle system (ESP), a working fluid of a pre-determined volume is guided from a working fluid storage chamber to the master brake cylinder device (HZE) by a pump, thereby generating the minimum pressure.

4. The control device (SE) determines the volume of the hydraulic fluid present in the storage chamber before return, compares it with a pre-determined operating volume, and if the existing volume is less than the pre-determined operating volume, an additional volume for reaching the minimum pressure through the pump is sucked from the pre-chamber of the master brake cylinder to the storage chamber through the seal lip of the piston of the master brake cylinder, and subsequently pumped from the storage chamber to the pressure region of the master brake cylinder. The method according to claim 3.

5. After at least a portion of the additional volume has been pumped to the pressure region, this step is repeated at least once, and then the volume of the hydraulic fluid present in the storage chamber before return is determined and compared with the pre-determined operating volume. If the existing volume is less than the pre-determined operating volume, an additional volume for reaching the minimum pressure through the pump is sucked from the pre-chamber of the master brake cylinder to the storage chamber through the seal lip, and subsequently pumped from the storage chamber to the pressure region of the master brake cylinder. The method according to claim 4.

6. The control device (SE) recognizes the presence of the driver's braking desire through the pedal position and / or through the determination of the vehicle speed and / or through the driver interface. The method according to any one of claims 1 to 5.

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

8. The minimum pressure is sufficient to open the orifice hole when the master brake cylinder returns. The method according to any one of claims 1 to 7.

9. In a braking system (1) having a brake booster device (10) and a control device (SE) of a vehicle system (ESP), the brake booster device (10) is connected to the control device (SE) and can be connected to a pressure controller or includes a pressure controller. The control device (SE) is set up to determine whether the driver's braking request has ended after a previous braking process by the brake booster device (10), or whether the driver's braking request does not exist in the brake booster device (10) after a previous braking process by the brake booster device (10), to recognize whether there is an operating failure of the brake booster device (10), and to recognize whether there is an operating failure of the pressure controller. The pressure controller is connected to or included in the brake booster device, generates a braking pressure and / or a return pressure in a master brake cylinder device (HZE) of the brake booster device (10), and when the driver's braking request has ended or when the driver's braking request no longer exists, generates a pre-determined minimum pressure in the master brake cylinder device (HZE) by the vehicle system (ESP), thereby reducing the braking action on the brake member or causing the mechanism to return to a neutral position where there is no braking action, and thereby causing the return of the master brake cylinder. The generation of the minimum pressure is controllable by the control device of the vehicle system, braking system.

10. The braking system (1) according to claim 9, wherein the control device (SE) includes a control device (SE) of a vehicle stability system.

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