Robert Boschgmbh

Robert Mergenthaler

Heinz Leiber

Heinz Siegel

Edgar Schmitt

Hannes Bertling

Wolfgang Maisch

Wilhelm Zirps

Helmut Deringer

Dietmar Rischen

Ernst-Dieter Schafer

Harald Hellmann

Andreas Abbing

George Kehl

Electrohydraulic unit for regulating the pressure in vehicle braking

A damping device for pressure pulsations having a first hollow chamber for receiving hydraulic pressure fluid and a second hollow chamber. An elastic metal diaphragm that divides the second hollow chamber hermetically from the first hollow chamber. The second hollow chamber is evacuated, so that in the event that the metal diaphragm should possibly leak, no air can get into the hydraulic pressure fluid. The damping device can be used in hydraulic brake systems having a master cylinder and in other hydraulic systems.

Damping device, particularly for hydraulic brake system

The vehicle brake system has a master brake cylinder to generate brake pressure in at least one wheel brake. To avoid wheel locking during braking, a pressure control valve assembly and a pump for drawing pressure fluid out of the wheel brake are disposed between the master brake cylinder and the wheel brake. With its outlet, the pump communicates with the master brake cylinder via a damper chamber and a throttle having a pressure limiting valve disposed to bypass the throttle. The throttle and the pressure limiting valve have a common sleevelike housing, in which a cylindrically embodiment closing element is guided longitudinally movably. This closing element has a hollow collar on its face end that in the closing position fits over an inflow opening for pressure fluid. The collar of the closing element, in order to form the throttle, is provided with at least one aperture open toward this face end. The pressure limiting valve, which responds if the throttle is blocked with particles, overcomes the cross-sectional limitation of the throttle, so that the throttle can be self cleaning.

Apparatus for damping pressure fluctuations

The invention relates to a device for a hydraulic unit, in particular in anti-skid systems for vehicle brake systems, which has a radial piston pump. The eccentric driven by a drive shaft in the pump meets pump pistons also located in the pump, usually in the region of high stroke variation speed. An resultant mechanical and hydraulic vibration, which causes noise and annoying movement at the brake pedal, is counteracted according to the invention in that a resilient intermediate element is disposed between the pump pistons and the eccentric element, and the eccentric is driven via a torsionally elastic coupling.

Device for anti-skid brake system

A system for feedback-free ABS control in hydraulic brakes for mobile units, motor vehicles, motorcycles, and the like, equipped with a pedal-actuated master brake cylinder with a hydraulic brake booster and at least one isolation or shutoff valve in the form of a 3/2-way magnetic valve, which in normal operation is supplied with pressure by the master brake cylinder booster and is also assigned a plunger-piston for performing an ABS control. A check valve is disposed in the connecting line between the isolation valve, the ABS magnetic valve and the plunger-piston, or in a common supply line from the dynamic circuit of the master brake cylinder to these three actuating elements, as additional protection for the isolation valve and to assure the required brake pressure, even in the case of a failure, to keep the chambers of the hydraulic isolation valve and the rear chamber of the plunger-piston under pressure and in this way arrest the pistons so that they cannot move during normal braking operation. A pressure control valve can be disposed parallel to the check valve to limit the pressure in case of expansion of the fluid in the chambers, for example, by heating.

Method and apparatus for feedback-free ABS control

A brake booster in which a servo piston is slidably supported in a housing. The transmission of a brake force is effected via a piston rod protruding into the housing, and a work chamber is formed between the piston rod and the servo piston. After the opening of a valve, this work chamber can be filled with brake fluid from a reservoir or supply container via a pump or the like. A return line also leads out of the work chamber back to the supply container, via a further valve. To improve the closing or sealing behavior of the valves, the first valve is to be embodied for admitting the brake fluid from a valve cone, or its shoulder, the valve cone extending axially in a blind bore of the servo piston, and a valve seat formed out of a valve bushing. The second valve is likewise embodied as a seat valve, and an element connected with the valve cone cooperates with an element connected with the piston rod.

Brake booster

A brake booster having a brake valve disposed inside a booster piston, the brake valve comprises a valve bushing including a valve seat and a slide that is pressed by a spring against the valve seat of the valve bushing. The slide is supported with play at a great distance from the valve seat, so that it can be pivoted slightly around the vicinity of its bearing. The pivotability of the slide facilitates its centering in the valve seat, so that the valve closes dependably even in the presence of bearing tolerances or valve seat tolerances. Seals required for sealing off the slide have an elastic behavior, and are disposed in the vicinity of the bearing. As a result, reliable sealing is assured despite the pivotability of the slide.

Brake booster for vehicles

A brake pressure control valve including a housing, a control bushing secured therein, a control slide and a travel simulator movable relative to the control bushing and having a spring. The travel simulator has a pressure piece which is rounded on its side toward the control slide. Toward the pressure piece, the control slide is also rounded. Between the control slide and the pressure piece there is a force transmitting member having two plane parallel end faces. A centering means surrounding the force transmitting member and embodied like a rubber-elastic bushing centers the force transmitting member relative to the longitudinal axis of the control slide and orients the end faces transversely to said longitudinal axis. The control slide, the force transmitting member and the pressure piece form roller pairs, which during the actuation of the brake pressure control valve enable relative movements between the pressure piece and the control slide without generating notable radial force components.

Brake pressure control valve

A brake valve for feeding selectably different levels of fluid pressure into at least one pressure receiver, which is a component of a vehicle brake system. The brake valve includes a first, normally open valve having a ball and a second valve, which is normally closed by a closing spring and which likewise has a ball. The latter ball is pressed by pressure provided by a pressure supply apparatus against a ball seat. A compensation piston acted upon by this pressure is also provided, which presses against the ball in the opening direction of the second valve. Because of the compensation piston, the second valve is easily opened, so that brake pressure can be sensitively controlled.

Brake valve

A hydraulic brake force amplifier is proposed, which has a control valve actuatable via a travel-imparting spring which directs the exertion of pressure medium from a supply source as an auxiliary force. The travel-imparting spring disposed subsequent to the brake pedal provides sensitive response by the control valve. If the auxiliary force fails, the action of the travel-imparting spring is precluded, so that pedal travel is not used unnecessarily. In order to effect this preclusion, a barrier piston is used, which is exposed on one side to the force of a spring and on the other side to a varying pressure, so that it does not seize due to corrosion and always remains in a functionally ready condition. The combination of the brake force amplifier with an anti-wheel-lock apparatus is possible. The hydraulic brake force amplifier is preferably applicable in vehicle braking systems for passenger cars and light trucks.

Hydraulic brake force amplifier

A brake force amplifier for the brake system of a motor vehicle, whose control valve is activated by means of a travel-limiting flexible element. The travel-limiting flexible element is arranged outside of the amplifier, decentralized from the control valve. This arrangement saves space, and is easily disconnected should the auxiliary force fail. This is accomplished by engaging an hydraulic circuit, which is intended to transfer the motion of the travel limiting flexible element, with the assistance of a disengagement device. The disengagement device has a piston, which is subject to spring pressure on one side and to reservoir pressure on the other side and which eliminates the effect of the travel-limiting flexible element with the aid of a piston rod.

Brake force amplifier

A hydraulic brake booster for a vehicle brake system which has a control valve, actuatable via an excursion-limiting spring, which directs the flow of pressure medium from a supply source as an auxiliary force means. The excursion-limiting spring disposed subsequent to the brake pedal provides for sensitive response on the part of the control valve. In event the auxiliary force fails, the excursion-limiting spring is made ineffective so that pedal travel does not occur without being utilized. A shut-off mechanism is included to make the excursion-limiting spring ineffective has a shut-off member dependent on brake actuation and to which a motion pulse dependent on brake actuation can be imparted in the area of its outset position. In this manner, the shut-off mechanism is used during each occurrence of braking and thus cannot seize as a result of corrosion.

Growing community of inventors

Markgroeningen, Germany

Robert Mergenthaler