Abstract: A controller includes an initial current value calculation unit calculating an initial current value to open a normally open linear solenoid valve when a hydraulic pressure is shifted from a pressure reducing state or a pressure holding state to a pressure increasing state, a valve opening amount increasing unit reducing the energization amount from the initial current value so that a valve opening amount of the normally open linear solenoid valve increases, an offsetting necessity determination unit determining based on a predetermined condition whether or not the energization amount needs to be offset to an increase side when the valve opening amount increasing unit reduces the energization amount, and an energization amount offsetting unit offsetting at least once the energization amount to an increase side only for a predetermined time period when it is determined that such offsetting is necessary.

Abstract: A brake system of a vehicle with a regenerative braking function, such as a hybrid electric vehicle. A regenerative braking hydraulic pressure line connects a master cylinder with a wheel cylinder. A regenerative control valve opens and closes the regenerative braking hydraulic pressure line. A proportional control valve is disposed in the regenerative braking hydraulic pressure line. The proportional control valve includes a spool, and output characteristics of the proportional control valve vary in response to an amount of pressure applied to the spool. A spool operator changes the amount of pressure applied to the spool.

Abstract: A vehicle brake hydraulic pressure control unit including a base body including a brake fluid flow path and a mounting hole portion having a bottom sealing surface and an inner circumferential sealing surface and an assembled part which is assembled into the mounting hole portion so as to communicate with the flow path. The assembled part includes a lower end sealing portion hermetically contacting with the bottom sealing surface of the mounting hole portion to form a lower side sealing portion and an outer circumferential sealing portion hermetically contacting with the inner circumferential sealing surface of the mounting hole portion to form a circumferential sealing portion. A hermetic accommodation space is defined by the lower side sealing portion and the circumferential sealing portion.

Abstract: A pneumatic brake system that includes at least one pneumatic latching valve; a single device, such as a solenoid, for providing momentary pilot signals to pneumatic latching valve; a source of pressurized supply air in communication with the pneumatic latching valve; a spring brake or other pneumatic device in communication with the pneumatic latching valve; and, optionally, an indicator device for monitoring and displaying the state of the pneumatic latching valve. Upon receiving a first momentary pilot signal the pneumatic latching valve changes from closed to open and delivers pressurized air to the spring brake. Upon receiving a second momentary pilot signal, the pneumatic latching valve changes from open to closed and exhausts pressurized air from the spring brake to the external environment. The valve remains “latched” in its current state until the signaling device is energized and the next momentary pilot signal is received.

Abstract: A brake hydraulic pressure control apparatus is provided with wheel cylinder pressure inference value acquisition means (step 402) for acquiring an inference value of the wheel cylinder pressure, master cylinder pressure inference value acquisition means (step 404) for acquiring an inference value of the master cylinder pressure by utilizing a wheel cylinder pressure inference initial value, reaction force compensation amount acquisition means (step 406) for acquiring a reaction force compensation amount which is a value depending on the variation of the master cylinder pressure caused by the flowing of brake fluid during an ABS control, and differential pressure inference value acquisition means (step 410) for acquiring an inference value of the differential pressure between the master cylinder pressure and the wheel cylinder pressure by adding the reaction force compensation amount to the difference between the master cylinder pressure inference value and the wheel cylinder pressure inference value.

Abstract: A braking control apparatus includes a brake operating member, a hydraulic circuit supplying a wheel cylinder hydraulic pressure to a wheel cylinder, a pump generating a hydraulic pressure so that the wheel cylinder hydraulic pressure reaches a value in response to an operation of the brake operating member, a circulation conduit provided at a portion of the hydraulic circuit, the circulation conduit through which a partial amount of brake fluid discharged from the pump is circulated back to the pump, a pressure regulating valve adjusting a pressure difference between an upstream side of the pressure regulating valve connected to the wheel cylinder and a downstream side, and a controlling device calculating, on the basis of a circulation flow rate of the brake fluid passing through the pressure regulating valve, an applied current to the pressure regulating valve for obtaining a target of the pressure difference and controlling the applied current.

Abstract: The invention relates to an automobile braking system with grip prediction and continuous control of braking pressure, including a hydraulic circuit which regulates braking pressure by controlling a proportional pressure value (8) which maintains the necessary pressure on the brake piston (6) in order to perform suitable braking. Braking control is permanently performed by a control system capable of recognizing actual grip conditions at all times and of establishing the ideal pressure conditions on the braking piston (6), said pressure being under optimal control at all times, ensuring that none of the wheels of the vehicle are subject to excessive skidding. Automobile braking can also be performed manually when the value (4) is in a standby position or in the event of a malfunction of the automatic braking control.

Abstract: A brake device includes: a mechanical pressure regulating part having a high-pressure port, a low-pressure port, a pilot pressure input port, and an output port which outputs fluid pressure corresponding to the pressure supplied to the pilot pressure input port by fluid pressures supplied to both of the high- and low-pressure ports, to a chamber for a master piston; a high-pressure source connected to the high-pressure port and the pilot pressure input port; a low-pressure source connected to the low-pressure port and the pilot pressure input port; and an electrically-operated pilot pressure generating part which includes control valves for controlling flows of the brake fluid between the high-pressure source and the pilot pressure input port, and between the low-pressure source and the pilot pressure input port, respectively, and which outputs desired fluid pressure to the pilot pressure input port by controlling flow of the brake fluid with control valves.

Abstract: An apparatus and a system include an actuator assembly configured for controlling a movement of a manual mechanical linkage shaft in a manual brake system for a vehicle wheel. An electric motor drives the actuator assembly wherein a manually applied force to the manual mechanical linkage shaft is modulated or pulsed. A lock and release assembly is configured for engaging and disengaging the actuator assembly to and from the manual mechanical linkage shaft. Means actuates the lock and release assembly to engage the actuator assembly to the manual mechanical linkage shaft, and disengage the actuator assembly from the manual mechanical linkage shaft.

Abstract: A base body has flow path configuring portions, has inlet and outlet ports, a central mounting hole 31, a central flow path 51 penetrating the central mounting hole 31, first inner and outer mounting holes 32, 33 disposed upstream side of the central mounting hole 31, second inner and outer mounting holes 34, 35 disposed downstream side of the central mounting hole 31, a third mounting hole 36 disposed below the second outer mounting hole 35, a wheel side sensor mounting hole 46 disposed on an extension of the outlet port 22L between the first inner mounting hole 32 and the second inner mounting hole 34, and a hydraulic pressure source side sensor mounting hole 45 disposed on a center line X of the base body so as to straddle to extend to the flow path configuring portions across the center line X.

Abstract: A control unit 20 includes an initial current value calculation unit 22 for calculating an initial current value when a caliper pressure shifts to a pressure increasing state, a target current value setting unit 23 which, when no pressure increasing cycle was performed last time, estimates a road surface friction coefficient, determines a target differential pressure based on the road surface friction coefficient so estimated, and sets a current value corresponding to this target differential pressure as a target current value, and a valve opening amount adjusting unit 25 which reduces an energization amount from the initial current value towards the target current value with a predetermined gradient.

Abstract: Disclosed a brake pressure control apparatus including a cylinder of which an upper portion is formed with a connection port connected with a brake line and a lower surface is formed with an air inlet/outlet port; a piston which is supported by a first spring disposed at a bottom surface of the cylinder; an opening/closing plate which is fixed to an upper portion of the piston so as to divide an inner portion of the cylinder and in which a fluid passage is formed at a center portion thereof; an introduction control valve which is disposed at an upper portion of the fluid passage H formed at the opening/closing plate so as to control a flow of the brake fluid introduced into the cylinder according to a brake pressure; a fluid passage opening/closing unit which is disposed at an inner portion of the opening/closing plate, and comprises a permanent magnet provided at one side thereof, a movement spring provided at the other side thereof and an opening/closing member disposed between the permanent magnet and the

Abstract: A pressure control valve arrangement is described for controlling the fluid pressure in an ABS brake system of a vehicle in such a manner that, in the event of a tendency of individual wheels of the vehicle to lock, the brake pressure in associated brake cylinders can be adaptively adjusted, at least two diaphragm valves which have diaphragms loaded by spring elements, as well as at least one electromagnetic control valve which can be activated by an electronic control device for the pilot control of the diaphragm valves. Also described is a method for producing the pressure control valve arrangement.

Abstract: A brake hydraulic pressure control device includes: a normally open linear solenoid valve configured to adjust a valve closing force depending on an power supply amount; a normally closed solenoid valve; and a controller configured to control switching of a hydraulic pressure within the wheel brake between a pressure increasing state, a pressure holding state, or a pressure reducing state, wherein: when shifting to the pressure increasing state from the pressure reducing state or the pressure holding state is made, the controller controls the power supply amount so that increasing is made at a first gradient up to a turning point target hydraulic pressure, and increasing is made at a second gradient gentler than the first gradient from the turning point target hydraulic pressure up to the end of the increasing; and the controller determines the turning point target hydraulic pressure.

Abstract: In a vehicle brake control device, a target W/C pressure depending on an amount of operation performed to a brake operating member, exhibits hysteresis due to a forward mapping dataset and a backward mapping dataset. The vehicle brake control device selects the forward mapping dataset or the backward mapping dataset based on the amount of operation performed to the brake operating member, and determines a current value of a current to be supplied to one of first to fourth linear valves. Therefore, it is possible to prevent a wheel cylinder pressure from changing too sensitively to the operation to the brake operating member and from changing even when the driver is not intentionally operating the brake operating member. This makes the driver experience an improved brake feeling.

Abstract: A damping force generating mechanism (V) comprises a front valve body (6) which allows working oil to flow from a first oil chamber (R1) to a second oil chamber (R2) under a predetermined resistance when lifted, and a rear valve body (7) which is disposed on the rear side of the front valve body (6) and allows working oil to flow from the second oil chamber (R1) to the first oil chamber (R1) under a predetermined resistance when lifted. An oil passage (5c) and a check valve (10) are provided to serve as a part of a flow path from the second oil chamber (R2) to the first oil chamber (R1). By disposing the oil passage (5d) in parallel with a center axis of the front valve body (6) and the rear valve body (7), the size of the damping force generating mechanism (V) can be reduced.

Abstract: Various brake control systems and methods are provided herein. In one implementation, a brake pressure control system having a shutoff valve (24) in a hydraulic conduit (26, 30) between a pressure origination source (16, 18) and a wheel brake (20), the shutoff valve selectively isolates the pressure origination source from the brake responsive to an indication that a wheel associated with the brake meets a skid condition, and an actuator assembly (28) comprising an actuator (34) that regulates fluid brake pressure after the shutoff valve isolates the pressure origination source from the brake. The actuator assembly operates independently of the shutoff valve and is coupled to the hydraulic conduit between the shutoff valve and the brake. The actuator assembly also effects displacement of the actuator for increasing and decreasing brake pressure. A controller (44) determines if the skid condition has been reached and controls the shutoff valve and the actuator assembly based upon the skid condition.

Abstract: An anti-skid control apparatus controls the value of electric current, which is being applied to the first solenoid valve and equal to or greater than the predetermined electric current value, to a value of electric current corresponding to the pressure difference between the master cylinder pressure and the wheel cylinder pressure at a time point where the pressure-increasing control is started; and changes the value of electric current in a direction to be reduced for a first period of time during the pressure-increasing control as the estimated amount of the wheel cylinder pressure reduced by the pressure-reducing control is increased, when the estimated amount of the wheel cylinder pressure reduced by the pressure-reducing control is equal to or greater than a predetermined value.

Abstract: A hydraulic brake unit applies braking force to a plurality of wheels of a vehicle according to the operation of a brake pedal. A pressure increase linear control valve supplies hydraulic fluid from an accumulator to wheel cylinders of disc brake units of the respective wheels. Pressure-sustaining valves are placed in passages that extend from a first passage to the rear wheel cylinders. A pressure-increase response-delay reduction section closes the pressure-sustaining valves for a predetermined period of time after starting the hydraulic pressure control to temporarily limit the inflow of hydraulic fluid into the wheel cylinders that communicate with the first passage. Thus, the amount of the hydraulic fluid that is supplied to the second passage is increased, and it is possible to reduce the hydraulic pressure response delay in the second passage.

Abstract: In a vehicle braking apparatus, a pressure control valve is controlled according to a brake operation amount of a brake pedal to thereby regulate hydraulic pressure and supply it to wheel cylinders. By controlling the pressure control valve by using hydraulic pressure output from a master cylinder as pilot pressure, the hydraulic pressure can be regulated and supplied to the wheel cylinders. A master cut valve capable of opening and closing a first hydraulic pipe that supplies the hydraulic pressure from the master cylinder to the wheel cylinders is provided. An external pressure supply pipe that supplies the pilot pressure to the pressure control valve is connected to the first hydraulic pipe on a side of the master cut valve closer to the wheel cylinders.

Abstract: In an ABS control, a vehicle brake control device detects a sudden change road in which a friction coefficient changes suddenly from a high value to a lower value and controls, based on the detection of the sudden change road, the currents to be supplied to a first and a second electrical motor in a first manner or a second manner, wherein in the first manner the currents are controlled so that the first and second electrical motors would eventually stop rotating if the motor control portion kept controlling the currents in the first manner for a sufficiently long time, and in the second manner the currents are controlled so that the first and second electrical motors would eventually start rotating in a reverse direction if the motor controlling portion kept controlling the currents in the second manner for a sufficiently long time.

Abstract: The present invention relates to a method for reducing deviations between the effective current and the measured current in a pulse-width-modulated current control, in particular for electronic brake control units of motor vehicles, wherein the measured current is determined at a certain predefined time within an actuation period and a compensation occurs by means of temperature-responsive and/or supply-voltage-responsive compensation variables which are added to the measured current such that a corrected nominal current is available for current control. The invention also relates to a circuit arrangement for actuating several inductive loads and comprises a circuit for PWM control of the load current. The method of the invention is implemented as a program in a microcomputer or microcomputer system that is electrically connected to the PWM circuit.

Abstract: A brake control apparatus for a vehicle includes an actuator and a controller that controls the wheel cylinder pressure to a target hydraulic pressure by driving the actuator in response to a braking request. The controller sets a ceiling value for the rate at which the wheel cylinder pressure is changed in accordance with a temperature, and the wheel cylinder pressure is changed at a rate that is equal to or lower than the ceiling value.

Abstract: A braking system for a vehicle, which can prevent an alteration in brake pedal toe force when a brake hydraulic pressure is increased or decreased based on a regenerative braking force obtained by a drive motor in an electric vehicle or hybrid vehicle, and a braking method thereof.

Abstract: A vehicle control device using brake hydraulic pressure includes a hydraulic unit having a housing and an electronic control unit having a casing. The housing of the hydraulic unit is mounted on a mounting surface of the casing of the electronic control unit so that the casing of the electronic control unit protrudes from the housing of the hydraulic unit to one side. On the protruding area of the casing, a bulge is formed in which a vehicle behavioral sensor is mounted. A control connector is also provided on the protruding area of the casing. The bulge does not protrude from the substantially square contour of the vehicle control device. Thus, the bulge will scarcely increase the installation space of the vehicle control device. A vehicle behavioral sensor is mounted on a small substrate.

Abstract: The invention concerns a brake valve arrangement of a vehicle having a trailer coupling and at least one controllable hydraulic consumer, with a brake valve (27). It is endeavored to provide a similar embodiment of a vehicle with such a brake valve arrangement. For this purpose, the brake valve (27) is combined with at least one control valve (11, 12) controlling the hydraulic consumer into forming a valve block (10) having several valve modules.

Abstract: The similarity groups of the pressure differential—current characteristics of solenoid valves are measured in advance, and the measurement results are used to select the solenoid valves to be used for first to fourth pressure increase control valves. Only solenoid valves in the same region in terms of their similarity group of the pressure differential—current characteristics are used for the first to fourth pressure increase control valves. A board on which the first to fourth control valves are mounted is provided with a mark unit that indicates the similarity group of the pressure differential—current characteristics of the first to forth pressure increase control valves. The mark unit includes a resistor. A brake ECU uses the resistance value of the resistor to identify the similarity group of the pressure differential—current characteristics of the first to fourth pressure increase control valves.

Abstract: An ABS control apparatus employs a normally-open linear solenoid valve as a pressure-increasing valve, and repeatedly performs ABS control composed of pressure-reducing control and linear pressure-increasing control. This apparatus determines an initial value Pw0 of an estimated wheel cylinder pressure value Pw in consideration of brake operation time before start of ABS control Tstp and vehicle body deceleration at the start of a first-time ABS control, and then determines the estimated wheel cylinder pressure value Pw during the ABS control on the basis of the value Pw0 and the pressure-reducing characteristic of a pressure-reducing valve. This apparatus determines instruction current supplied to the pressure-increasing valve during the linear pressure-increasing control, while using an estimated differential pressure Pdiff (=(Pw0?Pw)+Pup1+Pup2), wherein Pup1 and Pup2 are set in accordance with the time Tstp and additional brake operation during the ABS control, respectively.

Abstract: A braking system includes first and second electromagnetic opening valves and a bleeding mode setting unit. The first electromagnetic opening and closing valve is provided to a first brake fluid channel to communicate or block a first fluid pressure from a master cylinder to a wheel brake. The second electromagnetic opening and closing valve is provided to a second brake fluid channel to communicate or block a second fluid pressure from a power unit to the wheel brake. The bleeding mode setting unit is provided to set a bleeding mode in which each of the first and second electromagnetic opening and closing valves is opened and closed in order to perform an air-bleeding from each of the first and second brake fluid channels. The determining unit is provided to determine whether or not the bleeding mode setting unit is allowed to set the bleeding mode.

Abstract: A hydraulic brake apparatus for use in a vehicle having wheels and a brake operating member manually operable by a driver, the apparatus including a manual pressure source including (a) a hydraulic booster which boosts an operating source applied by the driver to the brake operating member and produces a first hydraulic pressure corresponding to the boosted operating force, and (b) a master cylinder which produces a second hydraulic pressure corresponding to the boosted operating force as an output of the hydraulic booster; a power pressure source which produces, by utilizing a power, a third hydraulic pressure irrespective of whether the brake operating member is operated; hydraulic brakes which are provided in association with the wheels, respectively, and include respective brake cylinders, and each of which, upon supplying of a hydraulic pressure to a corresponding one of the brake cylinders, applies a hydraulic braking force to a corresponding one of the wheels; a hub portion which is connected to each o

Abstract: A brake apparatus capable of applying a regulator pressure regulated by a regulator valve device to an assisting chamber, to obtain a smooth brake feeling, even when a brake pedal is operated by a vehicle driver, during an automatic braking operation. A first control valve is disposed in a power pressure passage for controlling hydraulic pressure in the assisting chamber to be increased. A changeover valve device is disposed in a regulator pressure passage for selecting either one of a communicating state and a shutting-off state of the passage. A second control valve is connected to the regulator pressure passage between the changeover valve device and the assisting chamber, and controls the hydraulic pressure in the assisting chamber to be decreased.

Abstract: A proportional pressure difference valve is disclosed between a master cylinder and normally open valves for supplying hydraulic pressure discharged from the master cylinder into wheel brake cylinders, which are connected to normally closed valves for reducing pressure. The normally open valve connected to one of the wheel brake cylinders in one hydraulic circuit is placed in its closed position, and the normally open valve connected to the other one of the wheel brake cylinders is placed in its open position and then the pressure difference valve is controlled on the basis of a monitored vehicle state variable to regulate a pressure difference between the pressure at the side of the master cylinder and the pressure at the side of the normally open valves.

Abstract: The brake hydraulic pressure control apparatus employs, as a pressure-increasing valve, a normally-open linear solenoid valve that can linearly adjust an actual differential pressure (difference between master cylinder hydraulic pressure and a wheel cylinder hydraulic pressure). This apparatus repeatedly executes, in principle, a control cycle in which a pressure-reducing control, holding control and linear pressure-increasing control make one set, while a “linear pressure-increasing control with holding period” is executed instead of the linear pressure-increasing control only in the first-time control cycle that is started in a state where a current-value-corresponding-to-actual-differential-pressure cannot correctly be obtained.

Abstract: A method shall render it possible that an especially favorable pilot control can be achieved with an electrically controllable hydraulic valve (10), in particular an analog/digital inlet valve of a friction brake of a motor vehicle brake system. To this end, an actuating current is applied to the hydraulic valve (10), which is determined by linking an available opening current characteristic curve (Iopen(?P)table) of the hydraulic valve (10) to a correction value (igrad), with the correction value (igrad) being predetermined depending on a number of parameters that are characteristic of the hydraulic valve (10).

Abstract: An operation-characteristic obtaining apparatus including an operation-characteristic obtaining portion which obtains, as an operation characteristic of an electromagnetic control valve which includes a coil and which is opened and closed according to at least a relationship between (a) an acting force corresponding to a difference of respective pressures of a working liquid on either side of the electromagnetic control valve and (b) an electromagnetic drive force corresponding to an electric current supplied to the coil, a relationship between (c) a valve switching current as an electric current that is supplied to the coil of the electromagnetic control valve at a time when the electromagnetic control valve is switched between a closed state thereof and an opened state thereof and (d) a difference at the time of the respective pressures on either side of the electromagnetic control valve; and a leakage detecting portion which detects, when the operation-characteristic obtaining portion obtains the operation

Abstract: A flange 62 having motor mounting through holes 63 is provided on a motor 6, motor mounting holes 19 are provided on a base body 1, so that motor mounting screw 61 are passed through the motor mounting through hole 63 from a back surface 1b side so as to be screwed into the motor mounting holes 19 to fix the motor 6 to the base body 1. Housing mounting holes 83 are provided on a control housing 8, housing mounting through holes 17 are formed on the base body 1 so as to be offset from portions which are in abutment with the flange 62, so that housing mounting screws 81 are passed through the housing mounting through holes 17 from the back surface 1b side so as to be screwed into the housing mounting holes 83 to fix the control housing 8 to the base body 1.

Abstract: In a pressure increase control valve, the size of a gap G between a plunger and a guide is 0.2 mm or greater, or a ratio between a diameter of a restriction and a seat diameter ds is 0.9 or less. Setting the size of the gap between the plunger and the guide to 0.2 mm or greater can decrease variations in an electromagnetic force with respect to a stroke of a valve body. In addition, setting the ratio between the diameter do of the restriction and the seat diameter to 0.9 or less can increase variations in a fluid force with respect to the stroke of the valve body. Therefore, it is easier to achieve a relationship between the electromagnetic force and a resistance force that is required in order to enable linear control of a differential pressure amount generated between upstream and downstream flows.

Abstract: A brake system includes a master cylinder, a slave cylinder and a wheel cylinder for braking a wheel. The master cylinder and the slave cylinder are connected via a first and a second fluid passage. A shutoff valve is provided in the first fluid passage. The first fluid passage communicates with the slave cylinder at a position in front of an advance limit of a cup seal of a piston of the slave cylinder. The second fluid passage branches from the first fluid passage on a side of the master cylinder relative to the shutoff valve. When the shutoff valve is closed, stroke loss is automatically minimized from the time the piston starts to advance to the time brake fluid pressure is generated.

Abstract: A method for controlling a vehicle wheel brake that includes applying a pulse width modulated voltage to an isolation valve located between a master brake cylinder and the wheel brake to develop a differential pressure across the isolation valve that is applied to the wheel brake. The differential pressure is a function of the duty cycle of the applied voltage. Because the operation of the isolation valve allows a flow of fluid through the valve, changes in the master cylinder pressure are passed through the isolation valve to the wheel brake.

Abstract: In a vehicular brake control system in which pressure upstream of a plurality of pressure increase control valves is variable, a brake control ECU sets a value of a current supplied to a solenoid coil in each of the pressure increase control valves in accordance with a physical quantity corresponding to a brake fluid pressure upstream of the pressure increase control valves, e.g., in accordance with a master cylinder pressure detected by a pressure sensor and an instruction current value for differential pressure control valves.

Abstract: An actuator for use in a vehicle hydraulic brake system having an anti-lock control and/or vehicle stability control function has a housing which also serves as the body of the master cylinder. The housing is formed with four wheel cylinder ports to be connected to the respective wheel cylinders through pipes. Since there is usually enough space in front of the housing, all of the wheel cylinder ports are formed in the front end face of the housing so that the pipes can be arranged in the large space in front of the actuator. The ports are arranged in the width direction of the vehicle with the ports at both ends located at a higher level than the other ports. With this arrangement, pipes can be easily mounted to and dismounted from the ports at both ends by turning a spanner without the possibility of the spanner interfering with components in the engine room, such as a relay box or the engine.

Abstract: A fluid-flow control system for a valve comprises a valve body and a bi directional main flow passage between a first and second fluid areas. The shuttle piston having a first face in direct communication with the second area and a second face in communication therewith through a bleed orifice. The second face is alternately exposed to the first fluid area through a backpressure passage and second orifice which alters the pressure differential across the shuttle piston. A second valve such as a solenoid operates to either close the second orifice wherein the shuttle piston is operable under differential pressure between the first and second pressure areas, or to close the second orifice wherein the shuttle piston is operable under differential pressure between the second pressure area and the backpressure passage. Filters at the fluid inlet and outlets protect the sealing components therein.

Abstract: A braking force retaining unit has a cut-off valve and a control unit. The cut-off valve retains predetermined brake hydraulic pressure at the wheel cylinders until a predetermined releasing condition is established, even after the depression of a brake pedal is released when a vehicle is stopped. When the predetermined releasing condition is established, the retained brake hydraulic pressure is released, when the depression of the brake pedal is released, the control unit controls the cut-off valve so as to retain the brake hydraulic pressure while reducing the retained brake hydraulic pressure at a first reduction rate. When the predetermined releasing condition is established, the control unit controls the cut-off valve so as to allow the retained brake hydraulic pressure to be reduced at a second reduction rate which is faster than the first reduction rate.

Abstract: A brake hydraulic pressure control apparatus includes a pressure-increasing valve disposed between a master cylinder and a wheel cylinder; a pressure-reducing valve disposed between the wheel cylinder and a reservoir; and a hydraulic pump for pumping brake fluid from the reservoir (secondary circuit) so as to return the brake fluid to a primary circuit between the master cylinder and the pressure-increasing valve. Through control of these valves, brake hydraulic pressure within the wheel cylinder is controlled. In addition, the hydraulic pump is driven at least over a period in which the brake hydraulic pressure control is performed. When the vehicle is in a predetermined state which indicates that the driver does not have an intention of performing the brake operation, both the pressure-increasing valve and the pressure-reducing valve are opened over a predetermined period of time so as to establish communication between the primary circuit and the secondary circuit.

Abstract: A method for determining a variable representing a hydraulic pressure drop across a valve of a brake circuit, in which a control pulse, designed such that abrupt braking pressure changes are suppressed, is applied to the valve, and in which the hydraulic pressure drop across the valve is determined from the knowledge of the control pulse.

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 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 braking apparatus for a motor vehicle having a service braking system (A) fed by a central hydraulic unit (3) and an emergency braking system (B). A simulator (M) resists a forward motion of an actuator member (D, 16) for a master cylinder (17) to define a reaction corresponding to the progress of a braking operation. Admission solenoid values (9a-9d) and exhaust solenoid values (14a-14d) connected to the wheel brakes (2a-2d) modulate pressurized fluid supplied by a central hydraulic unit (3) in effecting the braking operation. Sensors (8, 13a-13d, 24, 29) in the motor vehicle detect various braking parameters that are communicated to a computer (C) to control the solenoid valves (9a-9d; 14a-14d) such that the braking operation is a function of the travel of the actuator member (D, 16).

Abstract: A hydraulic brake device includes a hydraulic pressure supply passage for reducing the output hydraulic pressure by a first proportional solenoid valve and supplying it to a hydraulic passage leading from a pressure adjusting valve to the wheel cylinders, a second proportional solenoid valve disposed between the hydraulic pressure supply passage and the pressure adjusting valve for reducing the hydraulic pressure supplied from the hydraulic pressure supply passage, and a check valve parallel to the second proportional solenoid valve. Hydraulic pressure control during automatic brake control is carried out by the first and second proportional solenoid valves.

Abstract: A brake fluid pressure maintaining apparatus for a vehicle, having: a master cylinder; a check valve; and, a normally-open-type electromagnetic valve including an electromagnetic coil, a fixed core, and a movable core, and in the brake fluid pressure maintaining state, it is closed and, in the brake fluid pressure no-maintaining state, it is always opened, and by changing the value of the current, an attracting force is changed; by setting the attracting force at a given value, the brake fluid pressure to be maintained on the wheel brake side is set; and, when it is closed, in case where the brake fluid pressure of the wheel brake is higher than the attracting force of the given value, it is opened against the attracting force to thereby reduce the brake fluid pressure of the wheel brake down to the given value.