417results about "Brake cylinders" patented technology

A fluid-pressure brake system for a vehicle having a parking brake function in which, in response to actuation of an electrical parking brake signal transmitter, and without actuation of a brake pedal, at least one wheel brake of the brake system is actuated via an actuator to which the fluid is admitted. A parking brake module is provided in which there is integrated an electronic control unit as well as valve devices that are electrically actuatable by the electronic control unit. The electronic control unit actuates the parking brake function upon receiving from the parking brake signal transmitter an electrical actuating signal demanding actuation of the parking brake function and, as part of the parking brake function, the electronic control unit controls the admission of fluid to the actuator by means of the electrically actuatable valve devices.

A brake stroke sensor and an steering sensor are individually and collectively provided. A brake stroke sensor includes a force-receiving plate, a second plate movable relative to the force-receiving plate, a spring disposed between the plates and operatively connected to the pushrod, a strain gauge bridge mounted on the force-receiving plate and a microcontroller capable of converting the strain gauge bridge signal into digital data. A steering sensor includes a mechanical interface operatively connected to a nonmoving member and a moving member, an encoder capable of transforming the rotational motion of the mechanical interface into an electrical signal, and a microcontroller capable of calculating, from the electrical signal, a count indicative of the relative positions of the members. A combined brake stroke and steering sensor may include individual and common elements of both the brake stroke and steering sensors described above. The brake stroke, steering sensor and combined brake stroke and steering sensor may utilize a modem for transmitting data to a system controller over an electrical bus.

Disclosed is an accumulator comprising a cylindrical shell including a cylindrical portion, a partitioning member for partitioning the interior of the shell into a hydraulic chamber and a gas chamber, and a port including a hydraulic fluid flow path for communicating the exterior of the shell and the hydraulic chamber. The variation of the pressure of a hydraulic fluid flowing into the hydraulic chamber is accommodated by expansion and compression of a gas in the gas chamber according to expansion and contraction of the partitioning member. The port is approximately airtightly inserted into the cylindrical portion of the shell, and is welded to an outer circumference of the cylindrical portion by means of welding.

A friction member driven by a motor is pressed against a rotating element that rotates integrally with a wheel to give a pressing force to the rotating element, thereby applying braking force to the wheel. Control means controls the control circuit that controls the motor. In order to apply braking force to the wheel, the control means commands the control circuit to drive the motor once or a plurality of times at a predetermined time interval. Determining means determines a temperature of the friction member at the time when the parking brake starts braking the wheel. Setting means sets at least one of the number of driving of the motor, the time interval, and the target value of the pressing force. Therefore, a steady braking force with high efficiency is generated.

Disclosed is an accumulator comprising: a pressure vessel; an elastic bellows in which a compressed gas is sealed, an end of the bellows being fixed to an interior of the pressure vessel; a flow path having an opening communicating with the interior and an exterior of the pressure vessel; a valve connected to a movable end of the bellows to operatively close the opening according to elastic motion of the bellows; and a hydraulic chamber partitioned from a gas chamber formed in an interior of the bellows containing the compressed gas. The valve comprises an upper surface which can cover the opening, and plural circular protrusions which surround the entire circumference of the opening and can closely contact the circumference of the opening.

The invention is based on a system for controlling the braking action in a motor vehicle by means for adjusting the braking action independently of the driver's actuation. Upon recognition of a preselectable operating mode, for which at least the longitudinal velocity of the vehicle is found to be zero, a certain braking action is exerted. An operating mode of the type in question can be present when, for example, the above-mentioned creep suppression or the above-mentioned hillholding is desired. The core of the invention consists in that, upon determination of a preselectable longitudinal vehicle velocity during this operating mode, the braking action is increased independently of the driver. As a result of the monitoring of the longitudinal vehicle velocity according to the invention during the operating mode (creep suppression mode or hillholder mode), any motion of the vehicle unwanted by the driver is reliably prevented.

Provided is an electric brake capable of accurately estimating the brake pad temperature and securing a sufficient braking force and response. An electric brake has a disc rotor rotating with a wheel, an actuator for rectilinearly actuating a piston in the axial direction of the disc rotor by using an electric motor, a drive controller for controlling the drive of the actuator, a brake pad pressed by the piston to give a frictional resistance to the disc rotor in the direction of rotation, and a braking start position detector for detecting a braking start position of the piston where the disc rotor is brought into contact with the brake pad. The drive controller stores the braking start position detected by the braking start position detector as the maximum braking start position. When the braking start position shifts in the pressing force-increasing direction, the drive controller updates the value stored as the maximum braking-start position.

A vehicle brake monitor for a brake actuator including a housing, a reciprocal push rod extending through an opening in the housing and a stone shield mounted in the housing opening. An annular sleeve surrounds the push rod which is integrally formed of plastic including opposed sleeve portions which are generally semicircular in cross-section and a longitudinal integral flexible hinge portion interconnecting the adjacent sides of the sleeve portions, such that the annular sleeve may be received on the push rod, and an adjustable connector element interconnecting the opposed sides of the sleeve portions. The sleeve includes an elongated magnet, preferably a ceramic magnet having face portions which are magnetized with adjacent north and south poles and the stone shield includes a Hall-effect sensor which senses the location of the sleeve as the push rod reciprocates through the stone shield.

An improved diaphragm-type pneumatic brake actuator wherein the diaphragm is releasably secured to the piston as the diaphragm is inverted during actuation of the braking system of a vehicle thereby reducing wear of the flexible diaphragm and improving the performance of the brake actuator. In the disclosed embodiment, a rib or lip is formed on the surface of the diaphragm which receives the periphery of the piston as the diaphragm is inverted forming a mechanical interlock between the diaphragm and the piston thereby preventing spacing of the contact surface of the piston and the central portion of the diaphragm and frictional wear between the peripheral edge of the piston and the diaphragm. In the preferred embodiment, the piston includes an arcuate rim which extends away from the central portion of the diaphragm when the diaphragm is located in its extended cup-shaped position prior to actuation of the vehicle braking system and the diaphragm then conforms to the arcuate rim as the diaphragm is inverted and the diaphragm rib snaps over the piston rim as the diaphragm is inverted to actuate the vehicle braking system. The diaphragm rib may be molded on the surface of the diaphragm when the diaphragm is molded without any substantial increase in cost.

A process for operating the brake arrangement of a vehicle is presented, which comprises an electrically controllable service brake system, which is set to generate brake forces independently of driver actuation, andwhich comprises an electrically controllable parking brake system, which is set to generate brake forces and maintain these forces. So that the parking brake system or its electromechanical actuating unit only needs to cope with relatively small load situations, it is proposed that, when, for certain operating conditions, the parking brake system has to maintain brake forces which are greater than the brake forces it is able to generate itself, the service brake system generates the additionally required brake forces.

An automatic parking brake for a rail vehicle can lock the rail vehicle brakes in an applied position, such as by blocking the brake cylinder piston push rod from moving from an applied position to a release position. A control mechanism can be provided to remotely operate the automatic parking brake. A manual release can also be provided.

A motor current detecting device is provided in a parking brake control system for detecting electric current flowing through an electric motor. And current supply to the electric motor is stopped in case of carrying out a parking brake releasing operation, when a time period in which a differentiated value of the electric current flowing through the electric motor is smaller than a predetermined threshold value exceeds a predetermined time. As a result, a partial braking condition, in which parking brake force partly remains even after the parking brake releasing operation, and which is caused by, for example, the elongation of the brake cable is prevented.

When a solenoid is operated so as to move an engaging pawl to a disengaged position (step S24), if displacement detection means (an angular position sensor and a controller) detects that a motor rotor has not been displaced by an amount equal to or exceeding a predetermined level, that is, if the motor has not returned by an amount equal to or exceeding the predetermined level within a predetermined time period, and the answer in step S26 is NO and the answer in step S27 is YES (the predetermined time period has passed), a defect in an unlocked condition (an unlocking failure of a park braking lock mechanism) is determined (step S28). In this case, a driver is notified of the failure, so that prompt action can be taken to rectify the unlocking failure of the park braking lock mechanism.

A vehicle control apparatus for controlling a prime mover and wheel brakes which are equipped in a vehicle with an automatic transmission. The vehicle control apparatus includes a prime mover stopping unit which stops and restarts the prime mover under predetermined conditions, and a braking force retaining unit which retains braking force of each of the wheel brakes. Even if the automatic transmission is set in a neutral range, the braking force retaining unit is controlled to retain the braking force of the wheel brakes for a first predetermined time after the operation of a brake operation member is disengaged.

A locking unit for the locking of the movement of a piston. An electromagnet is provided the armature, respectively the armature bar, of which acts on an operating element. The operating element co-operates with a catching element in such a way that the catching element blocks in a locking position the movement of the piston, respectively the catching element unlocks in an unlocking position the movement of the piston. Catching element and operating element co-operate surface-to-surface.

An electric parking brake system is equipped with a parking brake driven by an electric actuator for braking wheels of a vehicle, a vehicle condition sensing section for detecting vehicle conditions, a target braking force setting section for setting a target braking force on the basis of vehicle condition detected, compared and weighted by the vehicle condition sensing section so as to overcome a trouble of a part of sensing section, a parking condition detecting section for sensing a change of the vehicle condition from a stopping condition to a parking condition, and a control section for increasing a braking force according to the change in the vehicle condition so as to avoid a creep movement of the vehicle. Thereby, the electric parking brake system with a highly improved reliability can be provided.

The invention provides a brake control apparatus that improves the controllability of a vehicle in the control for restraining slip of the wheels. The brake control apparatus includes: wheel cylinders that apply braking force individually to wheels by supplying a working fluid; retention valves that are provided respectively upstream of the wheel cylinders and that are opened and closed so as to restrain slip of the wheels; a common control valve provided upstream of the retention valves to supply the working fluid to the wheel cylinders; and a control portion that controls the common control valve by different control laws to restrain fluctuations in pressure on a primary side of the retention valves caused by fluctuations in a capacity to which the working fluid from the common control valve is supplied, by opening or closing of the retention valves.

The present invention relates to a hydraulic vehicle brake equipped with a parking brake device, in particular for motor vehicles, including a brake housing in which a hydraulic service pressure chamber is delimited by a brake piston, wherein the parking brake device acts on the brake piston and, in the applied condition, can be locked by means of a locking device, and an energy accumulator cooperating with the brake piston is equipped with at least one integrated spring element. In order to realize a simple and low-cost parking brake function that complies with legal requirements, according to the invention, the parking brake device is operable by a pressure that is introduced into the service pressure chamber and enables charging the energy accumulator.

A valve unit for an electro-pneumatic brake control is connected to an input of an air-quantity-boosting valve for the aeration / venting thereof. A double-armature solenoid valve includes primary and secondary armatures each spring-loaded and actuated by common magnet coil. The primary armature is a switch for a vent valve; the secondary armature is a switch for an intake valve. When the coil is not drawing current, the armatures are in spring-loaded position, the intake valve blocking intake and the vent valve venting. When a first current flows through the coil, the primary armature enters switching position, with the secondary armature in spring-loaded position; the intake valve blocking intake and the vent valve blocking venting. When a second current greater than the first flows through the coil, both primary and secondary armatures are moved into switching positions, so that the intake valve admits air and the vent valve blocks venting.

The invention relates to a combination cylinder including a service brake cylinder as an active service brake with at least one pressure-medium-actuated service brake piston which actuates a brake mechanism via a service brake piston rod, and a spring store brake cylinder as a passive parking brake with a spring store brake piston which is actuated by pressure medium counter to the action of at least one store spring, with the spring store brake piston transmitting the force of the at least one store spring to the service brake piston rod by a force-transmitting gearing in the parking braking situation. The invention provides for the gearing to be designed such that the movements of the spring store brake piston and of the service brake piston rod are coaxial and the force transmission ratio becomes greater with progressive stroke of the spring store brake piston.

A vehicular brake system component is used in a brake system of a vehicle. The brake system component includes a sealable bonded component having a metal member and an elastic rubber member bonded to each other and located so as to touch a brake fluid.

The invention relates to a protection method for protecting from overheating in a vehicle brake system comprising at least one brake provided with at least one electromechanical actuator which comprises a pusher actuated by an electric motor to apply a force selectively onto friction elements of the brake, it being possible for the brake system to operate, at the request of the pilot of the vehicle, either in a controlled mode in which the pusher of the actuator is actuated by the electric motor so as to apply a braking force selectively to the friction elements in response to a braking instruction, or in a parking mode in which the pusher of the actuator is locked in a position in which it exerts a parking force on the friction elements. According to the invention, the method includes the step of acting, while the vehicle is at a standstill, while the brake system is in the controlled mode, and while the pusher is controlled to apply a force on the friction element, to switch automatically and without intervention from the pilot from the controlled mode to the parking mode.

PCT No. PCT / DE96 / 00917 Sec. 371 Date Feb. 23, 1998 Sec. 102(e) Date Feb. 23, 1998 PCT Filed May 25, 1996 PCT Pub. No. WO97 / 02971 PCT Pub. Date Jan. 30, 1997The vibration damper has a sleevelike shaped part comprising an elastomer as a diaphragm. The shaped part is received tightly on the opening end of a bore of a housing and surrounds an extension of a support body disposed in the bore. Provided on a side face of the extension is a groove, which communicates with a chamber in the extension. The shaped part, which on its outside is exposed to the brake fluid, with the inside of its jacket wall defines a hollow chamber, formed toward the extension of the support body and having atmospheric pressure. The vibration damper can be used in a slip-controlled hydraulic brake systems of motor vehicles.

A method of monitoring the condition of a power spring of a pneumatic spring brake actuator of a vehicle by comparing the stroke of the push rod during normal braking and by actuating the parking brake, wherein a defective power spring is indicated when the difference in the push rod stroke falls below a predetermined minimum. The brake actuator may also include a sensor determining the push rod stroke and signal a defective power spring.

A brake system includes a master cylinder which generates brake fluid pressure by a braking operation of a driver, an electric motor-driven slave cylinder which generates brake fluid pressure based on an electric signal responsive to a braking operation of a driver, and a wheel cylinder for braking a wheel by the brake fluid generated in the master cylinder or slave cylinder. During normal operation of the brake system, the brake fluid generated in the slave cylinder is transferred to the wheel cylinder. During abnormal operation of the brake system, the brake fluid generated in the master cylinder is transferred to the wheel cylinder. The brake system also includes an opening and closing valve in a fluid passage connecting the slave cylinder to the wheel cylinder. When a problem occurs with the slave cylinder, the opening and closing valve is closed for a predetermined amount of time.

The invention relates to a method of managing a parking force in a brake system for a vehicle equipped with at least one electric brake having at least one electromechanical actuator which comprises a pusher actuated by an electric motor to apply a force selectively onto friction elements of the brake, the method including the step of causing the pusher to exert a parking force that is initially equal to a nominal parking force on the friction elements so that the parking force is maintained in the absence of drive from the electric motor. According to the invention, the method includes the step of adjusting said parking force at least once.

A vehicle control apparatus for controlling a prime mover and wheel brakes which are equipped in a vehicle with an automatic transmission. The vehicle control apparatus includes a prime mover stopping unit which stops and restarts the prime mover under predetermined conditions, and a braking force retaining unit which retains braking force of each of the wheel brakes. Even if the automatic transmission is set in a neutral range, the braking force retaining unit is controlled to retain the braking force of the wheel brakes for a first predetermined time after the operation of a brake operation member is disengaged.

An actuating mechanism (1) for operating a parking-lock mechanism of the drive chain of a vehicle with an automatic drive. The actuating mechanism has a piston unit (4), a detent element and an electromagnetic operating device (6) for operating a release element (7), which is intended for deactivating the detent element (5). The piston unit communicates with an emergency unlocking mechanism (14) and is positioned to open the locking mechanism by way of the piston unit. The detent element, the piston unit and the release element interact such that the locking mechanism remains in the currently engaged state when the locking mechanism is open and the operating device is not electrified, as well as when the locking mechanism is closed and a fluid pressure is applied to the piston unit.