Abstract: A method for preventing a valve orifice from switching to the small size when a high build gradient is required includes briefly bleeding off a small amount of fluid at the upstream side of the valve. This momentarily reduces the pressure difference when beginning the pressure build. After the valve is opened with the large orifice, the fluid flow through the valve prevents a high pressure difference. The resulting build with the large orifice has the maximum pressure gradient.

Abstract: In a hydraulic braking system operated by an external force, for vehicles, in particular motor vehicles, having a primary pressure source which is operated by external energy and provide brake pressure to the wheel brakes during normal operation, and which also has a foot-actuated auxiliary pressure source which supplies the wheel brakes with brake pressure during emergency operation, to increase the degree of safety, a special hydraulic circuit is provided wherein, during emergency operation, only comparatively few valves between the wheel brakes and a hydraulic reservoir have to be closed so as to be free of leakage, while operational safety is increased by the valves being connected in series.

Abstract: A vehicle brake control system includes an electric fluid pump that, upon energization thereof, pumps brake fluid from a reservoir to a brake circuit at a position upstream of a pressure control valve, an inlet circuit connecting the inlet opening of the pump to a master cylinder, an inside gate valve installed in the inlet circuit, and a control unit that controls the pressure control valve, the inlet gate valve and the electric fluid pump and carries out a predetermined brake control to adjust the hydraulic pressure of the wheel cylinder by operating the pressure control valve. The control unit is configured to carry out a flow back control after completion of the predetermined brake control. The flow back control is a control wherein the inside gate valve is kept open having the electric fluid pump kept de-energized.

Abstract: A tank intended for an electrohydraulic braking system comprises, according to the present invention, a first chamber (7) for the supply of a primary hydraulic circuit of a master cylinder with brake fluid, a second chamber (9) for the supply of a secondary hydraulic circuit of the master cylinder (not shown) with brake fluid, a third chamber (11) for the supply of a hydraulic pump with brake fluid, and a fourth chamber (13), a measuring one, which accommodates a detection device, indicating when the brake-fluid level inside the tank is too low. The tank has a flow path for the interconnection of the first chamber (7), the second chamber (9) and the third chamber (11) when the hydraulic-fluid level is higher than a safety level, and for the fluid-tight separation of said chambers when the hydraulic-fluid level is lower than the safety level.

Abstract: In a brake control system for a vehicle, a target wheel cylinder pressure of each wheel is calculated in accordance with a braking force applied by the driver, a brake control mode is determined to be one of an increase pressure mode, a decrease pressure mode, or a maintain pressure mode, and a target increase/decrease force slope is calculated in accordance with a slip amount of the wheel. In particular, the target wheel cylinder pressure is calculated based on actual wheel cylinder pressure and the target increase/decrease pressure slope, set on the target increase/decrease force slope when starting anti-skid control, the target wheel cylinder pressure is calculated after starting the anti-skid control based on the most recent target wheel cylinder pressure and the target increase/decrease pressure slope, and the wheel cylinder pressure Pi is controlled so as to become equal to the target wheel cylinder pressure.

Abstract: A hydraulic brake device includes a master cylinder supplying pressurized fluid to plural brakes which respectively restrict the rotations of road wheels, a solenoid block mounted on the master cylinder and containing plural solenoid valves, and an ECU provided with a control board for controlling the solenoid valves to distribute pressurized fluid to the plural brakes and also provided with a case for containing the control board therein. The solenoid block and the ECU form an integrated structure, and the integrated structure composed of the solenoid block and the ECU is removably mounted on the master cylinder. Further, the ECU is secured to the solenoid block by screw bolts which are arranged within an area inside the external form of the control board. Thus, it becomes unnecessary to provide bolt seats for the screw bolt outside the case.

Abstract: An automotive braking system controls the flow of pressurized brake fluid from a tandem master cylinder to several wheel brakes via a pair of braking circuits. Each circuit features a pressure relief line having, in series, a normally-closed valve, low-pressure accumulator, pump, check valve, damping chamber, and throttling orifice. A bypass line includes a normally-closed bypass valve that is operated to interconnect the pressure relief lines of the first and second braking circuits downstream of the pump outlets to thereby reduce system response time when, for example, one or more wheel brakes are actuated to enhance vehicle traction or stability. Braking system redundancy is enhanced with a check valve incorporated in either or both circuits downstream of the bypass connection, or a second normally-closed bypass valve in the bypass line. Fluid pressure monitoring in either or both circuits is further useful in identifying bypass valve leakage.

Abstract: The present invention mainly relates to an improved-safety braking device, intended for reducing the injury risks concerning the driver, owing to the brake pedal if a collision happens, in particular a front impact and, more particularly, the invention deals with an electrohydraulic braking device having a variable hydraulic reaction. A braking device according to the present invention comprises a master cylinder (1) fitted with a pedal-feeling simulation cartridge (3), said master cylinder (1) being actuated by an actuating rod (11) connected to a brake pedal (12), said cartridge (3) comprising a resilient means (29) and compression means (38) for the resilient means (29). These compression means (38) can be actuated by a computer (81) on the detection of an injury risk concerning the driver's legs, so as to reduce the compression rate of the resilient means (29).

Abstract: A vehicular motor-driven brake apparatus includes an open circuit in which reciprocation of a master cylinder generating a brake pressure is caused by an actuator that operates according to a pedal operation amount, and brake fluid discharged from a wheel cylinder during pressure decrease is directly returned to a master reservoir subject to atmospheric pressure. A fluid amount replenishment control is executed during pressure increase of the master cylinder in which a master stroke is returned for only a predetermined time by operation of the actuator, and thus brake fluid is sucked up from the master reservoir to the master cylinder. Accordingly, when an ABS control continues for a long time period, even if the brake pedal is being depressed, reduced pressure brake fluid in the master cylinder is sucked up. Therefore, there is no limit to pressure decrease, and bottoming-out of the master cylinder does not occur.

Abstract: An anti-lock controller controls an anti-lock brake system so as to realize any of a pressure decreasing mode where a normally-opened electromagnetic valve is closed, while a normally-closed electromagnetic valve is opened, a holding mode where the normally-opened electromagnetic valve is closed and the normally-closed electromagnetic valve is closed, and a pressure increasing mode where the normally-opened electromagnetic valve is opened, while the normally-closed electromagnetic valve is closed. Then, in the holding mode, for example, in the event that a predetermined condition is established where the voltage of a power supply for a vehicle or the terminal voltage of the normally-opened electromagnetic valve is equal to or smaller than a set value which is determined in advance, a current value that is applied to the normally-opened electromagnetic valve is controlled so as to become smaller than a current value that is applied to the normally-opened electromagnetic valve in the pressure decreasing mode.

Abstract: A hydraulic braking system having an electronically controlled full power brake valve is disclosed. The hydraulic braking system supplies a braking output for a vehicle having at least one brake. The hydraulic braking system includes a primary valve assembly that is configured to receive a manually controlled input that varies the braking output of the braking system. The primary valve assembly includes a first spool valve configured to vary the braking output according to the manually controlled input. The hydraulic braking system also includes a secondary valve assembly integral with the primary valve assembly. The secondary valve assembly is configured to receive input signals from a programmable electronic controller and includes a second spool valve configured to operate with the primary valve assembly.

Abstract: A brake control system for a wheeled vehicle includes a field programmable gate array configured to perform the algorithm of brake control subsystems in a typical brake control system for a wheeled vehicle. The brake control subsystems typically include anti-skid control, brake temperature monitoring, built-in tests, and, in the case of an aircraft, nose wheel steering. The system also includes wheel speed sensors, brake temperature monitors, brake valves and associated control circuits, and brake valve monitors respecting brake valve current and voltage. The use of field programmable gate arrays to configure a brake control system avoids the obsolescence and shortened life of control systems previously dependent upon microprocessors and the like.

Abstract: An apparatus and method are provided for controlling a rear brake hydraulic circuit having a fluid storage element and a master cylinder supplying a volume of pressurized brake fluid to the rear brakes during the braking cycle in a pump-less anti-lock brake apparatus controlling the rotational speeds, during a braking cycle, of only the rear brakes of a vehicle having at least one front wheel, at least one rear wheel, and front and rear brakes acting on the front and rear wheels respectively, by determining whether the vehicle is operating lightly loaded at a light vehicle weight (LVW) or heavily loaded at a gross vehicle weight (GVW), providing rear dynamic proportioning (RDP) when a predetermined deceleration rate is exceeded during the braking event with the vehicle operating at LVW, and inhibiting RDP when the vehicle is operating at GVW. The apparatus and method also provide rear pressure control (RPC) during anti-lock braking.

Abstract: This master cylinder comprises a body (12) defining a primary pressure chamber (14) and a secondary pressure chamber (16), separated by an axially movable piston (22), the so-called secondary piston; means (28) for the hydraulic connection of the primary pressure chamber (14) with braking-force simulation means (30); and complementary moving and stationary means (32, 34) for the sealing of the hydraulic connection means (28). The moving and stationary sealing means (32, 34) are borne by the secondary piston (22) and the body (12) respectively. The secondary piston (22) is axially movable between a rest position, in which the complementary sealing means (32, 34) are spaced apart from each other, and a position in which said complementary sealing means (32, 34) are cooperating with each other.

Abstract: The present invention is directed to a master cylinder having a braking stroke simulator, wherein a master piston is slidably accommodated in a housing having an atmospheric pressure chamber and a master pressure chamber, and a simulator piston is slidably accommodated in the housing to define a simulator chamber. An elastic member is provided for applying a stroke of the simulator piston in response to braking operation force applied to a manually operated braking member. Thus, the braking stroke simulator transmits the braking operation force to the master piston through the simulator piston and elastic member. A cut-off seal member is disposed in the housing for supporting the master piston, and placed to be applied with the pressure in the master pressure chamber in front of it and applied with the atmospheric pressure behind it. And, a passage is formed in the master piston to communicate the simulator chamber with the atmospheric pressure chamber when the master piston is placed in its initial position.

Abstract: The present invention is directed to a hydraulic brake apparatus provided with a pressure source for generating hydraulic pressure, a pressure regulator valve for regulating the hydraulic pressure generated by the pressure source in response to an input state, a master cylinder having a master piston for defining a pressure chamber for receiving therein the hydraulic pressure fed from the pressure regulator valve, and a master chamber for discharging hydraulic braking pressure. The hydraulic braking pressure discharged from the master chamber is set to be lower than the hydraulic pressure in the pressure chamber, to produce a pressure difference increased in response to advance of the master piston. A wheel brake cylinder is operatively mounted on each wheel of the vehicle for applying braking force to each wheel. A pressure control valve is disposed between the master chamber and the wheel brake cylinder to control the hydraulic braking pressure in the wheel brake cylinder.

Abstract: The present invention describes an innovative IBS braking system in which the regulation components are integrated with the brakes. The specific location of the fluid inlet components at the bottom of the brake and the return components positioned at the top of the brake present advantages for the renewal of the brake fluid. In the case of electronic failure, braking control is assured by a specific isolation device integrated within the brake. The general architecture of the control system can be totally decentralized due to the ability to integrate the various regulation methods of the brake: sensors, computers, and solenoid valves. This new concept, “intelligent brake”, uses the various signals supplied by the vehicle's computers to self-regulate.

Abstract: There is a case where first and second pressurizing units press different portions of friction members to a brake disc so as to press the friction members to the brake disc with predetermined pressing force, thereby generating braking force. When the brake noise is generated, a distribution ratio of the pressing force is changed by changing at least one of the pressing force generated by the first pressurizing unit and the pressing force generated by the second pressurizing unit. Accordingly, when the friction member contacts the brake disc, it is possible to change pressure distributions between first portions and second portions, whereby the brake noise is reduced or suppressed.

Abstract: In a hydraulic braking system operated by an external force, for vehicles, in particular motor vehicles, having a primary pressure source which is operated by external energy and provide brake pressure to the wheel brakes during normal operation, and which also has a foot-actuated auxiliary pressure source which supplies the wheel brakes with brake pressure during emergency operation, to increase the degree of safety, a special hydraulic circuit is provided wherein, during emergency operation, only comparatively few valves between the wheel brakes and a hydraulic reservoir have to be closed so as to be free of leakage, while operational safety is increased by the valves being connected in seris.

Abstract: A two-wheeled vehicle able to assist wheels and keep a chassis in a stable posture at the time of abnormal operation without detracting from mobility at the time of normal operation, wherein, when some sort of abnormality is detected in the two-wheeled vehicle, an auxiliary wheel actuator disengages a projection and recess, whereby a first auxiliary wheel springs out toward a road surface together with a shank due to a biasing force of a coil spring. At the time of normal operation, the first auxiliary wheel is recessed in a step board.

Abstract: The invention relates to a braking system for a vehicle, comprising an electronic service braking system having at least one braking cylinder and a pressure control module which is associated with the braking cylinder, said pressure control module comprising a control chamber and a working chamber. The invention is characterized in that the working chamber is connected to an air supply by means of a supply line; the control chamber is connected to the air supply by means of a connecting line and an inlet valve; the control chamber is connected to the atmosphere by means of an outlet valve; the control chamber is also connected to a back-up braking system by means of a back-up line and a back-up valve; and a control system is provided for controlling at least the inlet valve and the back-up valve.

Abstract: A method for preventing a valve orifice from switching to the small size when a high build gradient is required includes briefly bleeding off a small amount of fluid at the upstream side of the valve. This momentarily reduces the pressure difference when beginning the pressure build. After the valve is opened with the large orifice, the fluid flow through the valve prevents a high pressure difference. The resulting build with the large orifice has the maximum pressure gradient.

Abstract: A micromachined actuator including a body or platform mounted to a suspension system anchored to a substrate. In one embodiment, the suspension system is comprised of a set of one or more spring flexures connecting the actuator body to the substrate with strain relief provided via connecting torsional elements. In another embodiment, the suspension system includes a first set of one or more spring flexures each with one end anchored to a largely rigid intermediate frame and the other end attached to the body. A second set of one or more flexures is attached between the intermediate frame and the substrate. A third actuator embodiment maximizes force electrode area to minimize voltage required for electrostatic actuation. A fourth embodiment provides electrical interconnect to an actuator or an actuator array using polysilicon with silicon nitride isolation.

Abstract: A braking system includes an accumulator positioned along the brake line between the wheel brake and a pump. The accumulator includes a cylinder defining a bore and a piston fitted within the bore. The cylinder defines an inlet and an outlet fluidically connecting the bore to the brake line. The outlet is axially spaced from the inlet and is positioned to be sealed closed by the piston when it is proximate to inlet. The accumulator stores a reserved volume of fluid that is not delivered to the pump via the outlet to thereby reduce the volume of fluid delivered to the master cylinder by the pump and prevent damage to the lip seals during ABS control.

Abstract: The present invention relates to a brake pressure control device, more particularly, for anti-lock pressure control and for automatic brake intervention for the purpose of traction slip control and/or driving dynamics control in automotive vehicle brake systems, including accommodating bores for pressure modulation valves arranged in a housing, pressure sensor connecting ports which lead into the housing and into which there are inserted pressure sensors that sense the pressure in a housing-side pressure fluid conduit respectively connected to a brake pressure generator. The pressure sensor connecting port either opens into the pressure fluid conduit between two accommodating bores that are directed into the housing, or is part of the pressure modulation valve.

Abstract: A high reliability and low power consumption anti-lock brake system is disclosed in the present invention. The two pilot valves in the present invention are controlled so as not to be energized concurrently. The secondary battery of the anti-lock brake system is charged by power supply and/or generator. An electric double layer capacitor comprising a housing made of functionally graded aluminum—ceramic material is used as the secondary battery.

Abstract: An antilock brake control system for a vehicle includes normally-opened solenoid valves and normally-closed solenoid valves, and diodes each capable of exhibiting a function of slowly decreasing an electric current supplied to a coil of each of the normally-opened solenoid valves when the supply of the electric current to the coil has been cut off. Each of the normally-opened solenoid valves is controlled so that it is switched over among a turned-on state in which a predetermined first electric current is permitted to flow through the coil, a turned-off state in which the supply of the electric current to the coil is topped, and a middle state in which a second electric current lower than the first electric current is permitted to flow.

Abstract: A brake control apparatus having a brake pressure controlling unit including normally-open-type electromagnetic valves for preventing a fluid pressure transmitted from a master cylinder to wheel brakes when the valves close and a control unit executing an anti-lock brake control resolving a lock tendency of the wheels by controlling the operation of the brake pressure controlling unit according to a result of judgment of the lock tendency of wheels, and simultaneously executing a brake force distribution control distributing front and rear brake forces by controlling the normally-open-type electromagnetic valves in correspondence with rear wheels to close in such a manner that the normally-open-type electromagnetic valves are opened when the brake force distribution control is finished, wherein the control unit finishes the brake force distribution control after a vehicle stops and a load applied ahead of the vehicle is released.

Abstract: A brake fluid pressure control device controls brake fluid pressures through control of fluid pressure control valves operated in accordance with control signals from, for example, a computer. Signal lines for supplying control signals to control circuits controlling coils of linear valve devices for some wheels (e.g., front-left and rear-right wheels) are connected to a brake ECU by a connector, and signal lines for supplying control signals to the control circuits controlling coils of linear valve devices for other wheels (e.g., front-right and rear-left wheels) are connected to the brake ECU by a different connector. Thus, even if one of the connectors starts operating abnormally, it is possible to supply control signals via the signal lines connected by the other connector and control linear valve devices for some of the wheels (e.g., a pair of diagonally located wheels).

Abstract: Noise produced during a supplemental brake apply is reduced eliminated by reducing the quantity of additional brake fluid supplied to the pump during the apply. The prime valve is opened only at the initiation of the supplemental apply to supply a predetermined small quantity of brake fluid to the accumulator and pump inlet and is then closed for the remainder of the apply. The quantity of extra fluid supplied can be retained by the accumulator and does not need to by blown off back to the master cylinder. The apply valve of the non-regulated wheel brake is controlled to regulate pressure to the regulated wheel brake through the apply valve thereof, which is left open while the release valve of the regulated wheel brake is left closed. The release valve of the non-regulated wheel is controlled to maintain a lower pressure at the non-regulated wheel, preferably equal to the master cylinder pressure whenever possible, while permitting fluid flow back to the accumulator.

Abstract: The invention discloses methods and control systems for controlling an electronically controllable brake actuating system for automotive vehicles, with a depressurized pressure medium supply reservoir (4), with at least one pressure source (20) which can be controlled by an electronic control unit (32), said pressure source being used to apply pressure to the wheel brakes (7,8,9,10) of the vehicle, with pressure sensors and pressure control valves (inlet valve 17,18; outlet valve 27,28) being associated with said wheel brakes, said pressure control valves being controllable in an analog manner by means of an electric variable in dependence on the differential pressure applied to them and connecting the wheel brakes (7-10) to the pressure source (20) in a pressure increase phase, being closed or becoming closed in a pressure maintenance phase and connecting the wheel brakes (7-10) to the pressure medium supply reservoir (4) in a pressure reduction phase.

Abstract: A hydraulic braking system is described having a brake master cylinder (10), at least two brake circuits (30, 32) which are hydraulically connected to the brake master cylinder (10), solenoid valves (58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80) which are individually assigned to the brake circuits (30, 32), and means for supplying voltage pulses to the solenoid valves (58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80), through which the hydraulic pressure in the brake circuits (30, 32) may be modulated, the solenoid valves (58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80) able to be supplied with activations which are individual for each wheel or specific to each brake circuit. Furthermore, a method of influencing a hydraulic braking system having a brake master cylinder and at least two brake circuits is described.

Abstract: In a vehicle in which an engine output power is transmitted to front and rear wheels through a transmission and an inter axle differential, a wheel lock prevention device is provided. The wheel lock prevention device comprises a differential lock mechanism for locking the inter axle differential, a detection element for detecting a wheel lock state of the front and rear wheels, and an operation element for operating the differential lock mechanism so as to lock the inter axle differential by operating the differential lock mechanism upon the detection of the wheel lock state.

Abstract: A brake system and a brake device for use with automobiles is provided in which braking energy stored in an auxiliary pressure source can be effectively used for braking, even if an electrical system fails. The vehicle brake system includes a proportional pressure control valve for generating braking liquid pressure by adjusting the braking energy stored in the auxiliary pressure source. A passage transmits the liquid pressure generated by a brake pedal stroke, a switching valve opens the passage in the powered condition and closes the passage in the off-powered condition, and an auxiliary control portion activates the proportional pressure control valve. Even in the off-powered condition, the high pressure accumulated in the auxiliary pressure source can be used to adjust the required braking liquid pressure at the proportional pressure control valve.

Abstract: A brake system and a brake device for use with automobiles is provided in which braking energy stored in an auxiliary pressure source can be effectively used for braking, even if an electrical system fails. The vehicle brake system includes a proportional pressure control valve for generating braking liquid pressure by adjusting the braking energy stored in the auxiliary pressure source. A passage transmits the liquid pressure generated by a brake pedal stroke, a switching valve opens the passage in the powered condition and closes the passage in the off-powered condition, and an auxiliary control portion activates the proportional pressure control valve. Even in the off-powered condition, the high pressure accumulated in the auxiliary pressure source can be used to adjust the required braking liquid pressure at the proportional pressure control valve.

Abstract: In a vehicle hydraulic brake system of a type adapted to release brake fluid discharged from the wheel cylinders into a reservoir for a master cylinder during pressure reduction phase of antilock brake control or vehicle stability control, the volume of the pressure chamber of the master cylinder can decrease until it becomes impossible to further increase pressure as a result of repeated pressure increase and reduction. An inexpensive solution to this problem is provided. The solution includes means for estimating the amount of pressure increase and/or pressure reduction of the wheel cylinders, and solenoid valves provided in a line connecting a pressure source with the master cylinder pressure chamber and adapted to be opened for a calculated time period.

Abstract: A vehicular braking force control apparatus includes a solenoid valve disposed between a master cylinder and the suction side of a hydraulic pump. A ripple absorption low-pressure reservoir is provided between the solenoid valve and the suction side of the hydraulic pump. The low-pressure reservoir is partitioned, by a partition member, into an operation liquid portion that communicates with an auxiliary suction passage and an air portion where air exists. A spring member for pressing the partition member toward the operation liquid portion side is provided in the air portion.

Abstract: A method of boundary self-adaptation for proportional poppet valve pressure control comprises implementing an estimator to estimate a boundary deviation of the valve. Then, a pressure command signal is detected. Next, a pressure command derivative over time is obtained. Then, determining which closing boundary should be updated is decided based on the sign of the pressure command derivative. Next, a pressure error is obtained by subtracting an actual wheel brake pressure from its pressure command. Then a modified pressure error is calculated. Next, a pressure command signal is evaluated to determine whether a braking maneuver is gentle. Next, the modified pressure error is implemented in the estimation. Finally, a boundary table is updated using the resultant boundary deviation estimate.

Abstract: A method and a device are described for controlling the brake pressure acting on a wheel brake in a braking system having a pressure generation device for generating a setpoint pressure (Pset) preset by a regulation, an intake valve for admitting a brake fluid into the wheel brake, and a pressure-limiting valve for limiting the brake pressure to a selectable threshold value. To improve the braking response of the wheel brake, it is suggested that the threshold value be set at the pressure-limiting valve as a function of the pressure buildup gradient.

Abstract: When a method for operating a reference speed judges that an ABS control is being executed, the method judges whether the ABS control is being executed to a front wheel or not. When the method judges that the ABS control is not executed to the front wheel, the method considers that the lifting of a rear wheel does not occur, and makes the reference speed follow the fastest wheel speed VRH. When the method judges that the ABS control is being executed to the front wheel, and further judges that a reference body deceleration is a predetermined value or more, the method considers that the lifting of the rear wheel has occurred, and makes the reference speed follow a speed VRM. The speed VRM is a wheel speed calculated in accordance with the following formula: VRM=&agr;VRL+(1−&agr;)VRH (0<&agr;<1), where &agr; character VRL indicates the slowest wheel speed, and a character &agr; indicates a default.

Abstract: A brake control system includes an ECU constructed to carry out pressure-increase assist control for restraining the opening of an OUT-side gate valve and opening inlet valves during a predetermined time when active brake control is switched from the state that it is effective for only one wheel cylinder to the state that it is effective for only another wheel cylinder.

Abstract: Noise produced during a supplemental brake apply is reduced eliminated by reducing the quantity of additional brake fluid supplied to the pump during the apply. The prime valve is opened only at the initiation of the supplemental apply to supply a predetermined small quantity of brake fluid to the accumulator and pump inlet and is then closed for the remainder of the apply. The quantity of extra fluid supplied can be retained by the accumulator and does not need to by blown off back to the master cylinder. The apply valve of the non-regulated wheel brake is controlled to regulate pressure to the regulated wheel brake through the apply valve thereof, which is left open while the release valve of the regulated wheel brake is left closed. The release valve of the non-regulated wheel is controlled to maintain a lower pressure at the non-regulated wheel, preferably equal to the master cylinder pressure whenever possible, while permitting fluid flow back to the accumulator.

Abstract: A combination brake and anti-lock system for a wheeled vehicle such as an aircraft includes an operator controlled source of pressurized hydraulic fluid for selectively applying hydraulic pressure to a hydraulically actuated wheel rotation braking device which responds to the applied hydraulic pressure to apply a braking force to a wheel of the vehicle to thereby arresting wheel motion. There is a low pressure hydraulic fluid return with a normally open hold valve in circuit between the source and the braking device for selectively opening and closing a fluid flow path from the source to the braking device and a normally closed decay valve in circuit between the braking device and the return for selectively opening and closing a fluid flow path from the braking device to the return.

Abstract: In a check valve of the present invention, when a pressure action direction of a fluid on a valve body is assumed to be X, a spring receiving surface that abuts with a seat surface that is at one end in an axial direction of the helical compression spring is made to incline with respect to a surface perpendicular to the pressure action direction X. Accordingly, an urging force of the helical compression spring on the valve body acts obliquely with respect to the pressure action direction X. Thus the valve body is pressed to a side wall surface when the valve is opened, and vibration of the valve body is inhibited. Accordingly, it is possible to embody the invention with an extremely simple structure in which the spring receiving surface is inclined with respect to the surface perpendicular to the pressure action direction X.

Abstract: A transmission member that transmits urging force of a helical spring to a valve body is disposed between the valve body and the helical spring. The transmission member changes a direction of an urging force transmitted to the valve body such that the urging force is oblique to a pressure action direction X. Accordingly, when a check valve is in an open state, the valve body is pressed against a side wall and thus vibration of the valve body is inhibited. Further, when the check valve is in a closed state, an angle &thgr; formed by the direction of the urging force transmitted to the valve body and the pressure action direction X is set to be between 8 degrees and 45 degrees. Accordingly, it is possible to simultaneously realize a fluid path opening/closing function and a valve body vibration inhibition function.

Abstract: The present invention relates to an electro-hydraulic brake system for motor vehicles which is controllable in a ‘brake-by-wire’ operating mode by the vehicle operator as well as independently of the vehicle operator, and which can be operated in a back-up operational mode where only operation by the vehicle operator is possible. The brake system includes an emergency pressure generator or master brake cylinder which has at least one pressure chamber and is operable by means of a brake pedal, and a hydraulic auxiliary pressure source whose pressure is used to act upon wheel brakes that are connectable to the master brake cylinder by way of at least one hydraulic connection closable by means of a separating valve, as well as an electronic control and regulating unit.

Abstract: In a vehicle hydraulic brake system of a type adapted to release brake fluid discharged from the wheel cylinders into a reservoir for a master cylinder during pressure reduction phase of antilock brake control or vehicle stability control, the volume of the pressure chamber of the master cylinder can decrease until it becomes impossible to further increase pressure as a result of repeated pressure increase and reduction. An inexpensive solution to this problem is provided. The solution includes means for estimating the amount of pressure increase and/or pressure reduction of the wheel cylinders, and solenoid valves provided in a line connecting a pressure source with the master cylinder pressure chamber and adapted to be opened for a calculated time period.

Abstract: A method and a device for controlling the slippage at at least one vehicle wheel in a closed loop. In order to reduce an unacceptable slippage at at least one wheel, the braking force at this wheel is influenced and wheel vibrations are determined. Furthermore, the tendency of the characteristic of the slippage is ascertained during a vibration, and the braking force is influenced as a function of the ascertained tendency.

Abstract: An electrohydraulic brake system where brake pressure is controlled by the combined action of an apply valve and a dump valve by the implementation of a method of controlling the voltage applied to the apply and dump valve. The EHB pressure control system receives a desired wheel pressure command and, with a caliper pressure feedback signal, implements an algorithm to compute one voltage command for the apply valve and another for the dump valve. The solenoids of the proportional apply and dump poppet valves are operated to control flow in or out of the brakes and modulate wheel pressure as required. The algorithm is used to control the electromagnetic poppet valves in all states of flow through the valve. The algorithm is a function of the existing pressure within the system and whether there is bulk or leakage flow through the valves.

Abstract: A vehicle hydraulic braking system responds to detection of an operator intended high braking intensity event to isolate vehicle brakes from the master cylinder and activate a motor driven pump to generate a maximum predetermined supply pressure, calibrated to provide activation of an anti-lock braking system, to the brake apply valves for an initial predetermined time. Thereafter, the supply pressure is reduced via an electrically controllable pressure relief valve responsive to sensed vehicle deceleration so as to decrease the supply pressure provided to the apply valve to a level just sufficient to provide the sensed vehicle deceleration. The high intensity braking event is detected via a rate of change of master cylinder pressure, pedal force or pedal travel.