Abstract: The invention relates to the damping of mechanical vibrations of components in apparatuses. In particular, the invention relates to the damping of components of brakes. For this purpose, at least one piezoelectric element is provided, which is in engagement with the vibrating component and electrically excited in such a way that it damps vibrations of the component.

Abstract: An arrangement for measuring a fluid pressure, comprising a pressure sensor portion (10), which is devised for accommodation in a recess (12), which is open at least at one end, wherein the pressure sensor portion (10) in relation to the recess (12) is to be dimensioned in such a way that the pressure sensor portion (10) is surrounded by a gap (14) for receiving fluid, wherein first and second surfaces (16a, 16b, 18a, 18b), which are situated on the pressure sensor portion (10) and in contact with fluid, are so dimensioned and aligned that forces, which are exerted by the fluid pressure on the first surfaces (16a, 16b) and push the pressure sensor portion (10) in the direction of the open end of the recess, are equal to or lower than the forces, which are exerted by the fluid pressure on the second surfaces (18a, 18b) and push the pressure sensor portion (10) away from the open end of the recess (12).

Abstract: A vehicle electro-hydraulic braking system having a fluid pressure accumulator of the pre-charged diaphragm type which is used to store fluid under pressure, charged by means of a fluid pump or compressor driven either by an electric motor or directly from the vehicle engine for supply to a valve system which is adapted to supply the brake or brakes of the vehicle with fluid pressure in accordance with the level of the driver's braking demand, the control of the accumulator pressure being arranged to lie within a fixed control range, with a cut-in pressure defining the lower limiting pressure of the control range and a cut-out pressure defining the upper limiting pressure of the control range, and there being a warning pressure range defined between a warning pressure level and the cut-in pressure, wherein at least one of the warning, cut-in and cut-out pressure levels is arranged to be controlled in dependence upon temperature.

Abstract: An anti-locking brake system for a land vehicle, which is set up in particular for traction control and vehicle dynamics control, comprises a pump (42) for actuating a wheel brake (37) which removes brake fluid from a brake pressure generating unit (31) and supplies it to the wheel brake (37), wherein a first valve arrangement (1) blocks in a non-actuated (normal) position (1.1) the connection between the brake pressure generating unit (31) and an input connection (42e) of the pump (42) and in at least one actuated position (1.3) establishes a primary flow connection (A), a first electromagnetic valve (50) establishes in a non-actuated position (50.1) the connection between an output connection (42a) of the pump (42) and the brake pressure generating unit (31), and blocks it in an actuated position (50.

Abstract: A method of detection and identification of pressure sensor faults in an electro-hydraulic braking system of the type comprising a brake pedal, respective braking devices connected to the vehicle wheels and which communicate with electronically controlled proportional control valves in order to apply hydraulic fluid under pressure to the braking devices, respective pressure sensors for measuring the hydraulic pressures at the individual braking devices, a hydraulic pump driven by an electric motor, a high pressure hydraulic pressure accumulator fed by the pump for the provision of hydraulic fluid under pressure which can be passed to the braking devices via the proportional control valves in order to apply hydraulic fluid under pressure to the braking devices in proportion to the driver's braking demand as sensed at the brake pedal, and a supply pressure sensor for monitoring the hydraulic pressure supplied to the electronically controlled proportional control valves.

Abstract: A pneumatic brake booster (10) has a booster housing (12), the interior of which is subdivided by at least one movable wall (14) into a vacuum chamber (16) and a working chamber (18). Along an axis (A) a control valve (20) for controlling a pneumatic pressure difference acting upon the movable wall (14) projects into the booster housing (12). The movable wall (14) is workingly connected to the outside of a substantially cylindrical control valve housing (22), in that a collar (34) of a plate (30) associated with the movable wall (14) is deformed along its periphery at least in sections radially into the control valve housing (22). In order to simplify manufacture of the brake booster (10), in the portion (36) of the control valve housing (22) overlapped by the collar (34) of the plate (30) a plurality of recesses (40) are provided, which are spaced apart from one another in peripheral direction and into which the collar (34) of the plate (30) is radially deformed.

Abstract: A voltage supply circuit for an ECU, of the type which uses a capacitor to hold charge for use in maintaining the supply during temporary supply interruptions, wherein a charge pump is provided for increasing the voltage available for charging the capacitor to a level above that of the supply to enable the stored energy of the capacitor to be boosted.

Abstract: A vehicle braking system comprising an electro-hydraulic braking system of the type which operates normally in a brake-by-wire mode wherein hydraulic pressure is applied to braking devices at the vehicle wheels (18a-d) in proportion to the driver's braking demand as sensed electronically at a brake pedal (10), and which, if the brake-by-wire mode should fail, operates in a push-through mode wherein hydraulic pressure is applied to the braking devices at the vehicle wheels (18) by way of a master cylinder (34) coupled mechanically to the braked pedal (10), and an electric parking braking system for enabling the braking devices to be actuated for parking braking purposes. For supplementing the push-through braking provided by the electro-hydraulic braking system in the event that the brake-by-wire mode has failed, it is arranged that the operation of the brake pedal (10) by the driver also causes operation of the electric parking braking system.

Abstract: An electro-hydraulic braking system of the type which operates normally in a brake-by-wire mode wherein hydraulic pressure is applied to braking devices at the vehicle wheels in proportion to the driver's braking demand as sensed electronically at a brake pedal (10), and which, if the brake-by-wire mode should fail, operates in a push-through mode wherein hydraulic pressure is applied to the braking devices at the vehicle wheels by way of a master cylinder (34) coupled mechanically to the brake pedal (10), the system including also an electric parking braking device for enabling the braking devices to be actuated for parking braking purposes but which is also arranged to be activated to supplement push-through braking in the event of failure of the brake-by-wire mode. Electro-hydraulic braking at the rear axle of the vehicle is allowed only when a control unit (13) of the electro-hydraulic braking system has confirmation that the electric parking device is in a satisfactory operational state.

Abstract: Electronically controllable brake booster with a vacuum chamber and a pressure chamber, which are separated from one another by a moveable wall, a control valve arrangement, which can be actuated by means of an electromagnetic actuating device and via which a pressure difference between the pressure and the vacuum chamber can be set, wherein the control valve arrangement takes up a holding position, a pressure build-up position, a pressure reduction position in accordance with a current generated as correcting variable by an electronic control unit and flowing through the electromagnetic actuating device, a cylinder-piston arrangement, which is connected to the brake booster and comprises a piston, coupled to a brake pedal, of a hydraulic cylinder which has a hydraulic connection leading to a wheel brake, a sensor arrangement for detecting a signal which is correlated with the pressure of the hydraulic cylinder and which reproduces the controlled variable, wherein the electronic control unit establishes a com

Abstract: A vacuum brake booster comprising a vacuum chamber (16) and a working chamber (18), separated by a movable wall (14) coupled to a housing (22). A control valve (20) includes a first valve seat (40) formed on a displacement valve member (38) and cooperating with a first valve seat member (42), to control a supply of atmospheric pressure to the working chamber. A rear side of the valve member is constantly subjected to pressure in the working chamber. When the valve member is displaced more than a predetermined distance in the actuating direction relative to the housing, a front side of the valve member is subjected to pressure in the vacuum chamber, such that a differential pressure acts on the valve member, to hold the valve member in a displaced position until pressure equalization between the first and rear sides of the valve member is effected.

Abstract: An apparatus (10) for controlling the road speed of a motor vehicle has an accelerator pedal (12), which is biased counter to its actuating direction into an inoperative position and is movable from the inoperative position into a neutral position, from which a further movement of the accelerator pedal (12) counter to the spring bias leads to an increase of the drive torque of the motor vehicle drive. A device for detecting the inoperative position of the accelerator pedal (12) is connected to a braking-force generator (40) and in the inoperative position of the accelerator pedal (12) causes the braking-force generator (40) to make a predetermined braking force available.

Abstract: A rear axle braking system for a vehicle has a primary electronic braking circuit supplied with a source of primary braking pressure and a mechanical back-up braking circuit supplied with a source of back-up braking pressure. The braking actuator receives braking pressure and thereby brakes a wheel on a vehicle axle. During braking, a changeover valve is normally actuated to apply the primary braking pressure to the braking actuator. In the event of an electronic system failure, the changeover valve is not applied and instead the source of back-up braking pressure is supplied to the actuator. A regulating valve is located in the back-up braking circuit between the source and the changeover valve and is operable as a function of axle loading and back-up brake pressure to control the supply of back-up braking pressure to the changeover valve. The application of additional braking pressure to a wheel can be limited if the loading on the axle is likely to result in vehicle instability when braking.

Abstract: A master cylinder includes a restraining device arranged between the first and second pistons for preventing the return spring from being compressed and expanded beyond a certain extent. The restraining device includes a first, substantially sleeve-shaped component and a second, substantially pin-shaped component. The pin-shaped component includes a flange which projects radially outwards. The sleeve-shaped component includes a first receiving flange which positively interacts with the flange of the pin-shaped component. The sleeve-shaped component includes at least one introduction opening which enables the flange on the pin-shaped component to be laterally introduced into the sleeve-shaped component. The end of the sleeve-shaped component includes a second receiving flange which positively interacts with a flanged projection on the second piston which projects radially outwards.

Abstract: A vacuum brake booster (10) has a vacuum chamber (18) and a working chamber (20), which are separated in a pressure-proof manner from one another by a movable wall (16). A control valve (22) having a housing (24), which is workingly coupled to the movable wall (16) and in which a first valve seat (64) is disposed, in order to achieve a pressure difference at the movable wall (16) controls the supply of at least atmospheric pressure to the working chamber (20) in dependence upon the displacement of an input element (26), which is coupled to the first valve seat (64), of the brake booster (10). Disposed in the control valve housing (24) is an armature (38), which cooperates with a permanent magnet (40) and which is coupled on the one hand to the input element (26) in actuating direction and on the other hand to the first valve seat (64).

Abstract: A vacuum brake booster (10) has a vacuum chamber (18) and a working chamber (20) separated from one another in a pressure-proof manner by a movable wall (16). A control valve (22), which comprises a housing (24) workingly coupled to the movable wall (16), has a first valve seat (50), which is disposed in the housing (24) and to achieve a pressure difference at the movable wall (16) is capable of controlling the supply of at least atmospheric pressure to the working chamber (20) in dependence upon the displacement of an input element (26) coupled to the first valve seat (50). For improved boosting of the brake force during emergency braking operations, an armature (38), which cooperates with a permanent magnet (40), is provided in the control valve housing (24) and is rigidly coupled on the one hand to the actuating element (26) in actuating direction and on the other hand to the first valve seat (50).

Abstract: A control valve retaining element (22) for a brake booster (10) has a hollow cylindrical base member (28) and a first retaining collar (30), which is connected to the base member (28) and has at least one side wall for supporting a bellows end (20). To enable such a retaining element to be manufactured less expensively and positioned easily and securely on an actuating rod (16) of a brake booster (10), a second retaining collar (36) extends radially inwards from a first end of the base member (28) and in peripheral direction, wherein the second retaining collar (36) comprises a first lateral face (38) for cooperation with a stop (44) of the actuating rod (16) and a second lateral face (40) lying opposite the first lateral face (38) for cooperation with a compression spring (46).

Abstract: The invention relates to an actuating apparatus (12) with automatic clearance adjustment for a vehicle hydraulic disk brake and includes a housing (14) having a base (16) and a shell (18) in which an open cylinder bore (20) is provided. For actuating the brake, a piston (24) is hydraulically displaceable in the bore. A mechanical actuating device for displacing the piston in the bore and for compensating lining wear comprises an expanding device (34) acting axially in a brake actuating direction and a length adjustable strut between the expanding device and the piston. The strut is formed by a first strut part (52) having a bolt shaped end, which is screwed into a second, substantially sleeve shaped strut part (54), which rests with a conical flange (68) against the piston. Between the bolt shaped end of the first strut part and the second strut part there is a cavity (90) which is to be filled with brake fluid and closed off in a fluid tight manner at one end.

Abstract: A brake pressure transducer is to be provided for a hydraulic vehicle brake system that can be actuated by initiating an actuating force (FB) via an actuating element (2) in order to generate a brake pressure for at least one wheel brake (3) by reducing the volume of a hydraulic chamber (4) and that is equipped with a brake force booster (13) in order to superimpose a primary servo force (FS1) on the initiated actuating force (FB). An additional hydraulic chamber (6) is provided whose volume likewise decreases on initiating the actuating force (FB).

Abstract: In an electronically controllable brake booster a value is sensed which is characteristic for the actual pressure characteristic in the pressure chamber. The actual pressure characteristic is checked for the existence of periodic oscillation components of a predetermined frequency band with a predetermined minimum amplitude. Upon the existence of such periodic oscillation components, the current flowing through an electromagnetic actuator for a control valve arrangement of the brake booster is decreased by a first predetermined value for a first pressure changing position. Further, the current for a second pressure changing position is decreased by second predetermined value.