Brake booster system, braking system and vehicle

Abstract

Brake booster device (1), comprising a reservoir (8) and a master brake cylinder (10) which has at least one chamber (12, 17) and at least one piston (22, 23) arranged in the chamber (12, 17), wherein the chamber (12, 17) is connectable to the pressure regulator (14) so ​​that the piston (22, 23) can be at least partially reset by means of the pressure regulator (14), wherein the chamber (12, 17) is connectable to the reservoir (8), wherein a valve (7, 9) is arranged between the chamber (12, 17) and the reservoir (8).

Description

[0001] The present invention relates to a brake booster device, a braking system and a vehicle. State of the art

[0002] EP 2 217 478 B1 shows a brake system with a clutch that can be switched by the brake pedal to decouple the drive device from the piston-cylinder unit.

[0003] DE 10 2010 003 602 A1 relates to a method for controlling / regulating an amplification of a braking force of a braking system.

[0004] DE 10 2011 006 746 A1 shows a braking system for a vehicle.

[0005] DE 10 2025 213 710 A1 discloses an electromechanical brake booster. Disclosure of the invention

[0006] The essence of the invention in the brake booster device comprising a reservoir and a master brake cylinder having at least one chamber and at least one piston arranged in the chamber is that the chamber is connectable to the pressure regulator so that the piston can be at least partially reset by means of the pressure regulator, wherein the chamber is connectable to the reservoir, wherein a valve is arranged between the chamber and the reservoir.

[0007] The background of the invention is that the pressure regulator can be used to improve the return capability of the brake booster device. In particular, in the event of a reduced return force due to increased viscosity of the brake fluid at low temperatures or in the event of a return mechanism failure, the pressure regulator can be temporarily activated. The valve closes access to the reservoir, so that the pressure built up by the pressure regulator remains in the chamber. The valve is arranged in such a way that, when pressure builds up in the chamber due to the pressure regulator, it prevents backflow of the brake fluid from the chamber into the reservoir.

[0008] Further advantageous embodiments of the present invention are the subject of the subclaims.

[0009] According to an advantageous embodiment, the valve is designed as a check valve. The check valve is arranged in such a way that it automatically closes when pressure builds up in the chamber due to the pressure regulator, preventing the brake fluid from flowing back from the chamber into the reservoir.

[0010] It is also advantageous if at least one spring element is arranged in the chamber, exerting a restoring force on the piston. This allows for compact and cost-effective reset during normal operation of the brake booster system.

[0011] Advantageously, no additional spring element is required in the area of ​​a mechanism, in particular outside the chamber, of the brake booster device, so that the brake booster device can be designed compactly.

[0012] It is advantageous if the spring element is dimensioned such that its spring force is sufficient to return the piston from a braking position to a neutral position during normal operation of the brake booster system. This minimizes the spring force acting counter to the braking force.

[0013] Advantageously, the pressure regulator can exert an additional restoring force on the piston if the spring force of the spring element is insufficient to return the piston to the neutral position. Thus, the pressure regulator can be activated if necessary to return the piston to the neutral position.

[0014] Furthermore, it is advantageous if the spring element is designed as a helical spring arranged on the piston. This allows the brake booster device to be designed compactly.

[0015] According to a further advantageous embodiment, the brake booster device has an electric motor and a mechanism by means of which the piston can be deflected and / or reset.

[0016] It is advantageous if the pressure regulator can exert an additional return force on the piston if the return force of the electric motor is insufficient to return the piston from a braking position to a neutral position. This allows the pressure regulator to be activated if necessary to return the piston to the neutral position.

[0017] The essence of the invention in the braking system is that the braking system has a brake booster device, in particular as described above or according to one of the claims relating to the brake booster device, a pressure regulator and a control device, wherein the pressure regulator can be operated by means of the control device.

[0018] The background of the invention is that the control device is configured to detect an application in which the restoring force acting on the piston is insufficient to return the piston to the neutral position. Furthermore, the control device is configured to activate the pressure regulator to provide sufficient hydraulic pressure to return the piston.

[0019] It is advantageous if the braking system includes a vehicle stability system, which includes the pressure regulator and / or the control device. Thus, no additional pressure source is required to reset the piston. The braking system can be designed compactly.

[0020] The essence of the invention in the vehicle is that the vehicle has a brake booster device as described above or according to one of the claims relating to the brake booster device and / or a brake system as described above or according to one of the claims relating to the brake system.

[0021] The background of the invention is that the reset capability of the brake booster device is improved.

[0022] The above embodiments and developments can be combined with one another as desired, where appropriate. Further possible embodiments, developments, and implementations of the invention also include combinations of features of the invention described above or below with reference to the exemplary embodiments that were not explicitly mentioned. In particular, those skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present invention. Short description of the drawing

[0023] In the following section, the invention is explained using an exemplary embodiment, from which further inventive features may arise, but to which the scope of the invention is not limited. The exemplary embodiment is illustrated in the drawing.

[0024] It shows: Fig.1 is a schematic representation of a brake booster device 1 according to an embodiment of the present invention.

[0025] The brake booster device 1 has an electric motor 6, a mechanism with a gear 5, a spindle 4 and a spindle nut 3, as well as a master brake cylinder 10 and a reservoir 8.

[0026] In the embodiment shown in the figure, the master brake cylinder 10 has a first chamber 17 and a second chamber 12 and is thus designed as a tandem master brake cylinder. Alternatively, the master brake cylinder 10 can also have only a single chamber in which a single piston with a single spring element is arranged.

[0027] The master brake cylinder 10 has a first piston 22 and a second piston 23, wherein the first piston 22 is arranged in the first chamber 17 and the second piston 23 is arranged in the second chamber 12. The second piston 23 can be deflected by means of the first piston 22. The first piston 22 is connected to a first spring element 16 and the second piston 23 is connected to a second spring element 11. The respective spring element (11, 16) is designed to exert a restoring force on the respective piston (22, 23). The spring elements (11, 16) are designed, for example, as coil springs.

[0028] The first chamber 17 is hydraulically connectable to the reservoir 8 by means of a first connecting line 24. A first valve 7 is arranged between the first chamber 17 and the reservoir 8.

[0029] The second chamber 12 is hydraulically connected to the reservoir 8 by means of a second connecting line 25. A second valve 9 is arranged between the second chamber 12 and the reservoir 8.

[0030] The first valve 7 and / or the second valve 9 is preferably designed as a respective check valve.

[0031] The master brake cylinder 10 is connected to a brake circuit system (not shown in the figure) by means of at least one supply line 26. Preferably, each chamber (12, 17) has a respective supply line 26 connected to a respective brake circuit.

[0032] The brake booster device 1 can be actuated by means of an actuating device 2, which can be connected, for example, to a brake pedal. The actuating device 2 is arranged such that a driver braking force applied to the actuating device 2 deflects a spindle 4. The spindle 4 is connected to the first piston 22 and deflects it.

[0033] The actuation can be an adjustment or movement of a mechanism, whereby a braking effect on a friction brake can be activated or released, for example the master brake cylinder 10 of the brake booster device 1 can be reset from a braking position in which a friction brake is active to a neutral position.

[0034] To boost the brake force, the electric motor 6 is configured to drive the spindle nut 3 via the gear 5. The spindle nut 3 is connected to the spindle 4 and configured to amplify the deflection of the spindle 4. An anti-rotation plate 20 is connected to the spindle, which prevents the spindle 4 from rotating with the spindle nut 3. For this purpose, the anti-rotation plate 20 is connected to tie rods 21 via bushings 19. When the spindle nut 3 rotates, the anti-rotation plate 20 is guided by the tie rods 21, so that the spindle 4 is deflected and brake pressure is built up in the master brake cylinder 10.

[0035] The spindle 4, the spindle nut 3, the gear 5 and the anti-twist plate 20 are arranged in a housing 18.

[0036] The brake booster device 1 is connected to a pressure regulator 14. For this purpose, a first supply line 15 is arranged between the first chamber 17 and the pressure regulator 14. A second supply line 13 is arranged between the second chamber 12 and the pressure regulator 14.

[0037] The respective supply line (13, 15) extends through a cylinder housing of the master brake cylinder 10. The respective supply line (13, 15) is arranged such that a volume flow from the pressure regulator 14 can flow into the respective chamber (12, 17) in any position of the respective piston (22, 23).

[0038] The pressure regulator 14 can be included in the brake booster device 1, arranged externally thereto and representing an independent device, or a driving stability system (ESP) can take over the role of the pressure regulator 14 (if several pressure regulators are present, the ESP can then also be designated as an additional pressure regulator).

[0039] The pressure regulator 14 can be connected to or comprise a pump and a storage device for a hydraulic fluid and can cause a certain fluid volume to build up or reduce a certain pressure at the master brake cylinder 10, with which a pressure can be generated against the movement for braking action at the master brake cylinder 10.

[0040] The pressure regulator 14 is operated by a control device not shown in the figures. The control device can be implemented as a component of the brake booster device 1 or separately from the brake booster device 1; for example, it can be a control device of a driving stability control system (ESP).

[0041] The pistons (22, 23) in the master brake cylinder 10 can therefore be reset using the hydraulic pressure generated by the pressure regulator 14. The pressure regulator 14 assists the spring elements (11, 16) in resetting the pistons (22, 23). The restoring force acting on the pistons (22, 23) is therefore the sum of the spring force of the first spring element 16, the spring force of the second spring element 11, and the hydraulic force of the pressure regulator 14.

[0042] The spring elements (11, 16) are dimensioned such that, during normal operation of the brake booster device 1, the spring force of the spring elements (11, 16) is sufficient to return the pistons (22, 23) to the neutral position after a completed braking operation, in which no braking force acts on the brake circuit system. In the case where the spring force of the spring elements (11, 16) is insufficient to return the pistons (22, 23), the pressure regulator 14 is additionally activated, generating additional pressure on the pistons (22, 23), which returns the pistons (22, 23).

[0043] This application occurs, for example, at low temperatures, which cause increased viscosity of the brake fluid.

[0044] Alternatively, there may be a failure of the electric motor 6, which can actuate a reset of the brake booster device 1 during normal operation.

[0045] The control device is configured to determine a pressure in the master brake cylinder 10 and to compare it with a predetermined cylinder pressure, wherein a preceding braking operation and the need for resetting are recognized when the pressure in the master brake cylinder 10 is greater than or equal to the predetermined cylinder pressure and there is no driver braking request.

[0046] A high internal pressure may remain in the chambers (12, 17), which must be relieved, advantageously by a reset. Any residual pressure in the chambers (12, 17) automatically pushes the pistons (22, 23) back until the force of the hydraulic pressure on the pistons (22, 23) and the frictional forces in the mechanism and the connected gear 5 balance out. In order to push the mechanism and the pistons (22, 23) further back towards the neutral position, a volume flow can be maintained in the master brake cylinder 10, for example by a pump of the pressure regulator 14 or a pressure adjuster. This can achieve a restoring force in the pistons (22, 23) that is greater than the frictional forces.

[0047] The control device is configured to infer the presence of a driver braking request by means of information about a standstill of the vehicle and / or by means of a pedal position of an accelerator pedal and / or by means of a position of a brake pedal on the vehicle and / or by means of determining a speed and / or a speed gradient of the vehicle.

[0048] The signals which the control device can receive to activate the reset function, in particular to operate the pressure regulator 14 for resetting, can be information about the presence of a driver braking request, a measured master brake cylinder pressure, an active brake light switch (which infers a braking request), an accelerator pedal position, from which it can be read whether acceleration (i.e. no braking) or braking should take place, or standstill information of the vehicle. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 2 217 478 B1

[0002] DE 10 2010 003 602 A1

[0003] DE 10 2011 006 746 A1

[0004] DE 10 2025 213 710 A1

[0005]

Claims

[1] Brake booster device (1), comprising a reservoir (8) and a master brake cylinder (10) which has at least one chamber (12, 17) and at least one piston (22, 23) arranged in the chamber (12, 17), characterized by , that the chamber (12, 17) is connectable to the pressure regulator (14) so ​​that the piston (22, 23) can be at least partially reset by means of the pressure regulator (14), wherein the chamber (12, 17) is connectable to the reservoir (8), wherein a valve (7, 9) is arranged between the chamber (12, 17) and the reservoir (8). [2] Brake booster device (1) according to claim 1, characterized by that the valve (7, 9) is designed as a check valve. [3] Brake booster device (1) according to one of the preceding claims, characterized by that at least one spring element (11, 16) is arranged in the chamber (12, 17), which exerts a restoring force on the piston (22, 23). [4] Brake booster device (1) according to claim 3, characterized by that the spring element (11, 16) is dimensioned such that a spring force of the spring element (11, 16) is sufficient to return the piston (22, 23) from a braking position to a neutral position during normal operation of the brake booster device (1). [5] Brake booster device (1) according to claim 4, characterized by that an additional restoring force can be exerted on the piston (22, 23) by means of the pressure regulator (14) if the spring force of the spring element (11, 16) is not sufficient to return the piston (22, 23) to the neutral position. [6] Brake booster device (1) according to one of claims 3 to 5, characterized by that the spring element (11, 16) is designed as a helical spring which is arranged on the piston (22, 23). [7] Brake booster device (1) according to one of the preceding claims, characterized bythat the brake booster device (1) has an electric motor (6) and a mechanism by means of which the piston (22, 23) can be deflected and / or reset. [8] Brake booster device (1) according to claim 7, characterized by that an additional restoring force can be exerted on the piston (22, 23) by means of the pressure regulator (14) if the restoring force of the electric motor (6) is not sufficient to return the piston (22, 23) from a braking position to a neutral position. [9] Brake system comprising a brake booster device (1) according to one of the preceding claims, a pressure regulator (14) and a control device, wherein the pressure regulator (14) is operable by the control device. [10] Braking system according to claim 9, characterized by that the braking system comprises a vehicle stability system, wherein the vehicle stability system comprises the pressure regulator (14) and / or the control device. [11] Vehicle comprising a braking system according to one of claims 9 or 10.

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