Abstract: A vehicle braking system has a self-apply control which is effective to control the vehicle wheels under braking situations, traction control situations and chassis control situations. The self-apply control includes an electronic control unit (ECU) to establish the operation of the brakes. A positive displacement pump is utilized to provide fluid during self-apply operation. The output pressure of the pump is controlled by a variable pressure isolation valve which is controlled by the ECU to establish the maximum pressure required during each situation such that excess fluid pressure is not generated at the pump. the isolation valve has a stepped diameter bore in which a valve spool is disposed. The valve spool and the bore cooperate to form a unique dampening structure. The valve land and the bore wall form a flow restriction to and from a dampening chamber formed by the bore step and the valve land.

Abstract: An electromagnetic valve is fitted with relief means and is made to have a compact diameter without increasing its axial length is provided. The electromagnetic valve is provided with a push bar capable of pushing the valve body toward the valve seat and a relief spring for urging the push bar toward the valve body are contained in a guide hole formed in the central portion of the moving core, wherein a stopper is provided to the moving core, the stopper being used for holding the valve body open by defining a limit to which the push bar is moved forward with respect to the valve body when the moving core is moved backward and for allowing the valve body to be closed by the relief spring when the moving core is moved forward. Thus, the valve body and the push bar are axially arranged separately from each other.

Abstract: A compressed-air disk brake for vehicles comprises an actuating device for applying brake blocks in the direction of a brake disk and a brake cylinder, which, on arrival of the compressed air, initiates a braking action via the actuating device. At least one control module, comprising individual pneumatic and electronic components, is incorporated into the brake and/or the associated brake cylinder. For example, the control module may be formed directly on the brake cylinder housing section which encloses the ventilation chamber.

Abstract: A hydraulic control valve device which effectively reduces noise, vibration, and harshness (NVH) effect. A piston 38 is slidably provided in the smaller diameter portion 32b of the magnet core. A valve seat 38a is formed on the piston 38, A spring 40 is provided between the piston 36 and the bore 31, The deflection of the spring 40 absorbs the operation impact created by closing the valve mechanism of the valve member 35a and the valve seat 38a.

Abstract: In a valve arrangement with a first and a second fluid connection (7, 9), a valve element (3) which is biased into a first position by a spring arrangement (4), in which the first and the second fluid connections (7, 9) are blocked from each other, an actuation means (17) in order to bring the valve element (3) into a second position in which the first and the second fluid connections (7, 9) are in a primary flow connection (A), a relatively large flow cross-section between the fluid connections is to be made, on the one hand, the force to be exerted by the actuation means, on the other hand, is to be relatively low in order to save costs, efforts, as well as installation space.

Abstract: This invention relates to an electro-hydraulic brake-by-wire system including a hydraulic pump and a plurality of valves to achieve a demanded braking force, and to achieve a desired brake pedal feel. The brake system includes a plurality of wheel brakes, a reservoir of hydraulic fluid, and a pump for selectively pumping hydraulic fluid from the reservoir and supplying pressurized hydraulic fluid to the wheel brakes for applying a braking force. The pump acts as a source of pressurized hydraulic fluid to the wheel brakes during normal brake apply, as well as during advanced braking functions as Antilock Braking (ABS), Traction Control (TC), or Vehicle Stability Control (VSC). An apply valve is associated with each of the wheel brakes for selectively permitting flow of pressurized hydraulic fluid from the pump to the associated wheel brake. A dump valve is associated with each of the wheel brakes for selectively permitting flow of pressurized hydraulic fluid from the associated wheel brake to the reservoir.

Abstract: The present invention relates to a hydraulic brake system for automotive vehicles operable by independent force which includes a master brake cylinder preceded by a hydraulic brake force booster that has a booster piston and a working chamber to which an auxiliary pressure source is connectable, wherein a valve device operable by way of an electromagnetic drive is provided which establishes a hydraulic connection between the working chamber and an unpressurized pressure fluid supply reservoir in a first switching position and a connection between the working chamber and the auxiliary pressure source in a second switching position. To ensure low-noise operation of the brake system and a sensitively controlled volume delivery of the pressure fluid, the valve device is provided with a slide valve (20) of analog operation.

Abstract: A modulator valve for an ABS system for heavy duty vehicles is disclosed. It uses non flow-through solenoid valve assemblies that simplify the machining and manufacturing costs associated with the present arrangement. This eliminates complex pilot passages and also achieves a quicker acting release of the brakes during normal service braking.

Abstract: An electromagnetic valve is arranged in a conduit between a master cylinder and an intake side of a pump in a brake control system. In the electromagnetic valve, a main communication path and a restricted communication path are formed. The main communication path is alternatively opened and closed by a main valve body. The restricted communication path is formed in the main valve body and alternatively opened and closed by an auxiliary valve body. A solenoid generates electromagnetic force to bias the auxiliary valve body in a direction of opening the restricted communication path. The auxiliary valve body is provided with an engaging portion for engaging with the main valve body to move the main valve body in a direction of opening the main communication path after opening the restricted communication path.

Abstract: A brake system for motor vehicles with an adjustable pneumatic brake force booster includes a control valve which can be actuated by an electromagnet independently of the driver's actions. A brake pressure controller generates signals which serve to actuate the electromagnet. In order to be able to implement a quick-action, low-noise pressure regulating system at low cost, the brake pressure controller (8) is formed by connecting in parallel an electromagnetic control circuit (60) that processes the nominal brake pressure signal (Pnominal) into a first current value (IA) and a regulating circuit (70) that processes a control difference (&Dgr;P) formed from the nominal brake pressure signal (Pnominal) and the actual pressure signal (Pactual) into a second current value IB, with the output variable (Inominal) of the brake pressure controller (8) being formed by adding together the two current values (IA, IB).

Abstract: This invention relates to a multidirectional valve, in particular for wheel-slip-controlled and/or automatic-brake-intervention-equipped hydraulic brake systems of automotive vehicles, which includes a seat valve member disposed axially movably within a valve housing as well as a valve slide movable relative to the seat valve member within the valve housing, with the valve slide connecting one or a plurality of pressure medium consumers (wheel brakes) alternatively to a pressure medium source (braking pressure generator) or to a pressure medium collector (low pressure reservoir) The valve slide is mechanically coupled with the seat valve member.

Abstract: A vehicle brake system having a wheel brake and first and second conduits in fluid communication with the wheel brake. A master cylinder having an outlet is in fluid communication with the first conduit for supplying pressurized fluid to the first conduit. The brake system further includes an isolation valve movable between a first position, wherein fluid is permitted to flow from the master cylinder to the wheel brake via the first conduit, and a second position, wherein fluid is prevented from flowing from the master cylinder to the wheel brake via the first conduit. The isolation valve is preferably a pilot-operated valve movable between the first and second positions by a pressure differential between the outlet of the master cylinder and the pressure in the second conduit between the boost valve and the wheel brake. A source of pressurized fluid is in fluid communication with the wheel brake via the second conduit.

Abstract: When a stroke speed exceeds a reference value of a stroke speed threshold value, a solenoid is energized to tract an armature, thereby opening an atmospheric valve independently of the position of a plunger. Consequently, power pistons, together with an output rod, are moved forward by a thrust corresponding to a pressure difference between a constant-pressure chamber and a variable-pressure chamber to perform a full-power braking operation. A reaction-adjusting mechanism contributes to an improvement in safety by functioning in such a way that when the part of the reaction force from the output shaft that is transmitted to an input rod reaches a predetermined value, a boosting ratio is increased, so that the reference value of the stroke speed threshold value can be set high to prevent unnecessary braking.

Abstract: A vehicle brake system which permits both anti-lock control and different controls of independent force braking operations. In an independent force braking operation, a starting brake pressure is built up in the return circuit in the wheel brakes by way of a precharging pressure generator and the pump and is modulated in the following control phase according to the control algorithms of the selected control. Interposed between the precharging pressure generator and the return pump is a change-over valve which has three switching positions, i.e., one closed, one open, and one throttled. The change-over valve adopts its open position in the filling phase and its throttled position in the control phase. It is so configured that the switching position is achieved as a function of the initial pressure in the inlet chamber but independently of the actuating force which actuates the valve.

Abstract: The invention relates to a hydraulically actuated cutoff valve which is provided as an intake valve for switching between a master cylinder and an intake side of a feed pump of a slip-controlled vehicle brake system. The invention sets forth that the cutoff valve is embodied with a valve closing body that has a valve tappet which passes through an annular actuating element and is in engagement with a rocker element embodied as a cup spring, which rests on an annular pivot bearing. If the actuating element is acted upon by pressure, it presses down an outer edge of the rocker element, and as a result a middle of the actuating element executes a pivoting motion in the opposite direction that closes the cutoff valve. The invention has the advantage of an economical cutoff valve that has only a small number of components, and the invention can be used in a hydraulic vehicle brake system.

Abstract: A hydraulic brake system includes a solenoid valve with a pressure-limiting function to such effect that a stroke movement of a valve tappet, which can be fulfilled in response to the electromagnetic control force, is variable by the action of a hydraulic control force. A first pressure fluid channel is connected to the hydraulic pressure generator and opens into the valve housing proximate the valve tappet, and a second pressure fluid channel opens into the valve housing remote from the valve seat and the valve tappet. The second pressure fluid channel is connected to a pump and at least one wheel brake and is connectable to the first pressure fluid channel depending on the position of the tappet. The hydraulic pressure of the braking pressure generator acts upon an actuating member which counteracts the closing movement of the valve tappet.

Abstract: A rodlike magnet valve having a magnetic part which is surrounded by a coil for actuating the valve. The magnet valve can be inserted into a receiving bore of a hydraulic block of a slip-controlled vehicle brake system. For fast, economical manufacture of the magnet valve, the magnet valve has a rotationally symmetrical base body, which has a through bore and a securing flange, as an extruded part without undercuts or tapered features. Along with the advantage of enabling fast, inexpensive manufacture of its base body, the magnet valve has the further advantage that the base body can be made from an economical reforming steel, which can be readily welded for fluid-tight mounting of a valve dome.