BRAKING SYSTEM WITH A PARKING BRAKE DEVICE WITH INCREASED OPERATIONAL SAFETY

Abstract

Braking system with a parking brake device for motor vehicles, comprising at least one first electrically actuated parking brake (FP1) intended for positioning on a first wheel, a second electrically actuated parking brake (FP2) intended for positioning on a second wheel, a control unit (UC) designed to generate a command to the first and second parking brakes (FP1, FP2) to exert a given parking brake force, means (D1, D2) for determining the operating state of the first and second electric parking brakes (FP1, FP2), wherein the control unit (UC) is also designed, in the event of a malfunction of the first parking brake, to generate a command to the second parking brake (FP2) to exert at least the given parking brake force to ensure the motor vehicle remains stationary.

Claims

[1] Braking system with a parking brake device for motor vehicles, comprising at least one first electrically actuated parking brake (FP1) designed for positioning on a first wheel, a second electrically actuated parking brake (FP2) designed for positioning on a second wheel, a control unit (UC) designed to generate a command to the first and second parking brakes (FP1, FP2) to exert a given parking brake force, means (D1, D2) for determining the operating state of the first and second electric parking brakes (FP1, FP2), wherein the control unit (UC) is also designed, in the event of a malfunction of the first parking brake, to generate a command to the second parking brake (FP2) to exert at least the given parking brake force to ensure that the motor vehicle remains stationary. [2] Parking brake system according to claim 1, wherein the control unit (UC) is designed to generate a command to the second parking brake (FP2) to exert an additional parking brake force in addition to the given parking brake force in the event of a malfunction of the first parking brake. [3] Parking brake system according to claim 1 or 2, wherein the control unit (UC) is designed to extend the power supply to the second parking brake in the event of a malfunction of the first parking brake during a power supply phase of the second brake, so that it exerts an additional parking brake force compared to the given parking brake force. [4] Parking brake system according to claim 1, 2 or 3, wherein the control unit (UC) is designed to re-supply the second parking brake in the event of a malfunction of the first parking brake after termination of a power supply phase of the second brake, so that it exerts an additional parking brake force compared to the given parking brake force. [5] Parking brake system according to one of claims 1 to 4, wherein means for determining the operating state of the first and the second electric parking brake comprise means for measuring the supply current of the electric motor and / or a position sensor of a movable element connected to a geared motor of the first and the second electric parking brake. [6] Braking system comprising a parking brake system according to one of the preceding claims and at least two service brakes, wherein the parking brakes are integrated into the service brakes. [7] Operating method of a parking brake system comprising at least one first electrically actuated parking brake (FP1) for positioning on a first wheel, a second electrically actuated parking brake (FP2) for positioning on a second wheel, and a control unit (UC) connected to the parking brakes and means for determining the operating state of the first and second electric parking brakes, the method comprising the following steps: a) Generating a command by the control unit to each parking brake to exert a braking force sufficient to ensure the vehicle remains stationary, b) Detecting the malfunction of the first parking brake, c) Generating a command by the control unit to the second parking brake to exert a parking brake force. [8] Operating method according to claim 7, wherein in step c) the second parking brake is controlled such that it increases the braking force exerted on the wheel up to a certain value. [9] Operating method according to the preceding claim, comprising a step for determining the standstill value by the control unit on the basis of information about the parking state of the motor vehicle. [10] Operating method according to claim 9, wherein the determining step includes taking into account the braking force exerted by the first parking brake in a fault condition. [11] Operating method according to any one of claims 7 to 10, comprising generating a message by the control unit to the driver informing him of the malfunction of the first parking brake.