Solenoid

About: Solenoid is a research topic. Over the lifetime, 19278 publications have been published within this topic receiving 114721 citations.

Automatically engaged emergency parking brake

Abstract: A control system for a vehicle parking brake-actuator which releases the brake when subjected to fluid under pressure and which automatically sets the brake by spring force when the fluid pressure is relieved therefrom, the actuator being controlled by a valve which blocks or allows the relief of fluid pressure from the brake-actuator. The control system includes a solenoid for moving the valve to pressure-blocking position, a spring for moving the valve to pressure-relieving position when the solenoid is de-energized, and includes an electrical circuit for de-energizing the solenoid and causing an automatic setting of the brake if the vehicle engine is stopped or if there is a loss of oil pressure or electrical power. The brake can also be set by the operator when the engine is running.

Single ended solenoid valve assembly

Abstract: A dual solenoid valve assembly is provided. The assembly includes a casing joined to a housing having a pressure inlet and outlet, an exhaust port, a first fluid path connecting the inlet and the outlet, and a second fluid path intersecting the first fluid path and connected with the exhaust port. A first valve seat is in the first fluid path and a second valve seat is in the second fluid path. A first solenoid coil is mounted within the casing and a first magnetic solenoid stop is mounted within the first coil. A first solenoid plunger is slidably mounted within the first coil biased away from the first valve seat. A first tubular valve stem is fixably connected with the first plunger for sealably contacting the first valve seat. A second solenoid coil is mounted within the casing on a side of the first coil opposite the housing. A second magnetic stop is mounted within the second coil and a second solenoid plunger is biased away from the stop and is slidably mounted within the second coil. A second valve stem is fixably connected with the second plunger. The second valve stem has a head for sealably contacting the second valve seat.

Security device and method

Abstract: Relative movement of members (10,11) of a lock is normally obstructed by an element (14) which can be moved by a solenoid (18) entirely into a recess in one of the members so that the one (11) and the obstructing element (14) can turn together relative to the other member (10) and solenoid. The arrangement may be used to prevent turning of a key-receiving member relative to a housing or as a clutch between two members mounted rotatably in a housing.

Current control method for a solenoid operated fluid control valve of an antilock braking system

Abstract: The solenoid control valves of a solenoid-operated automotive antilock braking system are cyclically controlled to enable the valves to operate in a stable, partially open position that provides a desired fluid flow while minimizing noise associated with acceleration and deceleration of the controlled fluid. After an incipient lock-up condition is detected and the solenoid valve has been energized to hold and/or permit a partial release of the brake pressure, the solenoid is initially de-energized for a defined interval designed to reduce the current to a scheduled value. In this interval, the solenoid current is re-circulated through a free-wheeling diode for a smooth decay, allowing the valve to slowly open in a smooth and stable fashion. Then the solenoid is pulse-width modulated (PWM) at a frequency and duty cycle designed to maintain the solenoid current at the scheduled value. The interval of PWM is relatively brief to avoid any instability associated with the current pulsation. At this point, the solenoid is re-energized just long enough to reach its steady state value, thereby returning the valve to a closed or nearly closed position, and completing the current control cycle. The solenoid is then de-energized and the cycle is repeated, allowing the controller to smoothly return the brake pressure to the system pressure while minimizing any attendant hydro-mechanical noise.

Brushless, separately-excited, variable-speed motor and AC generator/alternator with solenoid-wound, biphase AC rotor

Abstract: A rotating electrical machine includes a two-phase rotor having two non-rotating solenoid-wound rotor coil assemblies and two interleaved pole assemblies. Each pole assembly is magnetically coupled to its respective coil assembly and rotates together with the machine shaft. Each pole assembly has four or more elongated pole pieces, two of which couple with one pole of a coil assembly and two of which couple with the other pole of that coil assembly. An exciter circuit independently controls the power variables provided to the rotor with respect to the stator to provide a variable-speed, variable-frequency (VSVF) motor system or VSVF generator system. The exciter energizes the solenoid-wound rotor coils with biphase AC electrical excitation, to produce a radial, rotating magnetic field at the pole pieces.