Abstract:
A control valve for controlling fluid flow in a hydraulic control unit of a vehicular brake system includes a flux tube having an end cap, a thick tube section, and a thin tube section defining an interior volume. An armature is slidably received in the interior volume of the flux tube. A coil is provided about the flux tube. A collar covers a portion of the thin tube section and is spaced from the thick tube section so that an air gap is provided between the coil and the portion of the thin tube section not covered by the collar.
Abstract:
This invention relates to an electro-hydraulic brake-by-wire system including a hydraulic pump and a plurality of valves to achieve a demanded braking force, and to achieve a desired brake pedal feel. The brake system includes a plurality of wheel brakes, a reservoir of hydraulic fluid, and a pump for selectively pumping hydraulic fluid from the reservoir and supplying pressurized hydraulic fluid to the wheel brakes for applying a braking force. The pump acts as a source of pressurized hydraulic fluid to the wheel brakes during normal brake apply, as well as during advanced braking functions as Antilock Braking (ABS), Traction Control (TC), or Vehicle Stability Control (VSC). An apply valve is associated with each of the wheel brakes for selectively permitting flow of pressurized hydraulic fluid from the pump to the associated wheel brake. A dump valve is associated with each of the wheel brakes for selectively permitting flow of pressurized hydraulic fluid from the associated wheel brake to the reservoir. A master cylinder is operated by a brake pedal for pressurizing hydraulic fluid. An isolation valve is associated with each of the wheel brakes for selectively preventing flow of pressurized hydraulic fluid from the master cylinder to the associated wheel brake. A sensor senses the position of the brake pedal and generates a pedal position signal representative of the position of the brake pedal. An electronic control unit receives the pedal position signal, which signal is utilized to determine a brake demand. The electronic control unit controls the operation of the pump, and the apply, dump, and isolation valves associated with each wheel brake to achieve a desired braking force at each wheel brake based on the brake demand and to regulate pressure generated by the master cylinder to achieve a predetermined relationship between the pressure generated by the master cylinder and the position of the brake pedal, whereby a desired pedal feel is achieved.
Abstract:
A solenoid coil formed by winding a conductive foil tape upon a sleeve and method for making same. The coil includes a free standing wire termination which is wound into the coil. Alternately, the end of the foil tape can be folded to form a coil termination.
Abstract:
An antilock brake system for an automotive vehicle having a master brake cylinder and wheel brakes hydraulically connected to the master brake cylinder during normal vehicle braking including a power cylinder having an adjustable piston, an electric motor connected drivably to the piston through a selectively enagageable electromagnetic clutch, a solenoid operated valve situated in fluid communication with the wheel brakes and adapted to connect the master brake cylinder to the wheel brakes for a normal braking action and for isolating the master cylinder from the wheel brakes and connecting the wheel brakes to the power cylinder for antilock cycling of the wheel brakes, and an electronic controller and wheel speed sensors for detecting wheel slip whereby the controller triggers the operation of the solenoid valve to isolate the master cylinder from the brakes and to dump pressurized fluid from the brakes when a threshold wheel slip is detected, the clutch being disengaged during the pressure dumping stage of the antilock brake cycle as the motor drive circuit is closed whereby kinetic energy stored in a rotating motor armature may be used in a subsequent brake reapply stage of the antilock brake cycle.
Abstract:
A control valve for controlling fluid flow in a hydraulic control unit of a vehicular brake system includes a valve seat. A sleeve is mounted on the valve seat. An armature core is slidably received in the sleeve. The armature core has a passage extending between first and second planar end surfaces of the armature core. An armature body is formed from a moldable material onto the armature core. The armature body has a central section received in the passage of the armature core, a first end section extending from the first end surface of the armature core, and a second end section extending from the second end surface of the armature core. This control valve is particularly adapted to be mounted in a bore of a housing of a hydraulic control unit of an electronically controlled vehicular brake system.
Abstract:
A solenoid coil inverted within a flux casing has at least one lead wire extending through a flux ring mounted in an end of the flux casing. The coil is coupled to a circuit board or overmolded lead frame which is positioned adjacent to a valve body with a solenoid valve sleeve extending through the circuit board or lead frame into the coil. A flexible coupling allows the coil to move relative to the circuit board or lead frame.
Abstract:
An improved force transfer arrangement for use in a dual circuit master cylinder having a pair of nested concentric pistons for pressurizing a pair of respective fluid chambers, wherein the force transfer arrangement imparts an input force from an input piston on a pair of pistons such that the pair of pistons can move relative to each other to compensate for different travel lengths. The invention discloses three embodiments of the improved force transfer arrangement. A first embodiment includes a hydraulic fluid chamber in fluid communication with the input piston and the pair of pistons. A second embodiment includes a circumferentially arranged ball mechanism positioned between the input piston and the pair of pistons. A third embodiment includes a notched lever ring assembly positioned between the input piston and the pair of pistons.
Abstract:
A mounting bracket for an anti-lock brake/traction control system control valve including a three point suspension. The bracket includes a base portion adapted for attachment to a vehicle. Three supporting members extend perpendicularly from the base portion. Resilient annular isolators are disposed within apertures formed through two of the supporting members. Mounting pins for securing the control valve to the bracket are carried by the isolators. A third resilient isolator having a recess formed therein is carried by the third supporting member. An extended portion of the control valve is received in the isolator recess and supported thereby. The isolators cooperate with the mounting pins and the control valve extended portion to absorb acoustical and vibrational noise.
Abstract:
A method for assembling a hydraulic control unit of a vehicular brake system includes the following steps of: providing a sleeve having a closed end; sliding a spring over an armature to form an armature/spring subassembly; orientating the armature subassembly to produce a normally open valve or a normally closed valve; sliding the oriented armature/spring subassembly into the sleeve; sliding a valve seat into the sleeve; crimping a portion of the sleeve onto the valve seat to form a sleeve/valve seat subassembly; inserting the sleeve/valve seat subassembly into a bore of a housing. Two additional steps can be combined with the above listed steps to provide a method of assembling the control valve subassemblies described above on a hydraulic control unit. The additional steps include: inserting the sleeve/valve seat subassembly into a bore in a housing; and pressing a coil assembly about the sleeve.
Abstract:
A solenoid coil inverted within a flux casing has at least one lead wire extending through a flux ring mounted in an end of the flux casing. The coil is coupled to a circuit board or overmolded lead frame which is positioned adjacent to a valve body with a solenoid valve sleeve extending through the circuit board or lead frame into the coil. A flexible coupling allows the coil to move relative to the circuit board or lead frame.