Abstract:
This three-way pneumatic solenoid valve comprises: a first inlet (1) connected to a first pressure source (A); a second inlet (2) connected to a second pressure source (D); an outlet (3) connected to a chamber at controlled pressure (C); a hollow body (4) into which t here emerges each of the paths so as to be set in communication therein in a selective fashion with at least one other path; and an electromagnet (5) secured to the body and including a core plunger (5a) capable of actuating means suitable for establishing the selective communication.The latter essentially comprise a stationary valve (6) and a movable valve (7) housed in the hollow body, the stationary valve being capable of being open when the movable valve is closed and vice-versa, and these valves being defined by a shaft (60), a tubular and movable stopper member (67), and a sealed surface (70) actuated by the electromagnet.This solenoid valve makes it possible to control the pressure in the chamber (C) as a function of the pressures of the first and second sources, in proportion to a control current signal from the electromagnet.
Abstract:
A hydraulic braking circuit comprises at least one brake fluid source (26, 36), a master cylinder (10), the outlets of which are connected to at least one sub-circuit comprising at least one brake motor (14, 16), and which is controlled by way of a pedal (12), and an electronic control unit (22). It also comprises a pressure generator (24), and an electrovalve (28, 30) which is arranged in each sub-circuit, so as to establish a connection, when at rest, between the outlets of the master cylinder (10) and the associated brake motors (14, 16) and, in the excited position, between the outlets of the generator (24) and the associated brake motors (14, 16), the control unit (22) being capable of simultaneously controlling the functioning of the pressure generator (24) and the excitation of the electrovalve (28, 30).
Abstract:
The brake system comprises two hydraulic sub-circuits, each connecting a driving wheel and a free wheel to a working chamber of a master cylinder (1) connected to a general reservoir (20) of fluid under low pressure, and including a wheel anti-lock braking device comprising a three-way solenoid valve (51, 52, 53, 54) normally opening communication between an inlet of fluid under pressure and the brake motor, while, in the expansion phase of the anti-lock device, it closes this communication and connects the brake motor to a reservoir (21, 22) of fluid under low pressure to each sub-circuit. The device comprises a differential valve slide consisting of a valve of which one face receives the pressure prevailing in the associated brake motor (31, 32, 33, 34) and the other that as generated by a pump (45, 46) and, at rest, putting in communication the working chamber of the master cylinder (1) and the inlet of fluid under pressure. The valve slide isolates the brake motor from the working chamber of the master cylinder during the operation of the pump (45, 46). A differential pressure/underpressure valve (76, 77) associated with each free wheel closes, at rest, communication between the working chamber of the master cylinder and the suction inlet of the pump (45, 46), and opens this communication in the event of underpressure in the corresponding brake motor (31, 33) only when there is no pressure generated by the master cylinder (1).
Abstract:
A device for the control of a double-acting hydraulic jack (10) comprises in a main circuit, a distributor assembly (28, 28', 34, 34') electrically controlled and commanding the putting of each of the two chambers (14, 16) of the jack selectively in relation with a source of fluid under high pressure (20, 26) or with a reservoir of fluid at low pressure (24), and an auxiliary circuit controlled by a mechanism (76) sensitive to the position of the piston (12) of the jack (10). The auxiliary circuit comprises a slide distributor (50) which ensures the return of the piston (12) of the jack (10) into a rest position in the event of a failure of the electrical control mechanism by governing the distributor assembly (34, 34') of the main circuit.
Abstract:
The device comprises a pilot slide (27) controlled by a pressure differential (P-P') determined by an electromagnetic pilot valve element (43) located in a return circuit to a tank (7) which is common to both the hydraulic installation and a branch pipe (8). The device preferably includes an isolating valve (40) connected to the pilot valve element (43) so as to isolate a pilot chamber (30) in the event of a failure of the electromagnetic actuator.
Abstract:
Hydraulic booster device intended to be arranged in parallel with a primary actuation circuit between an actuator mechanism and a receiver, the device comprising an electromagnetic valve mechanism (10) arranged between an actuator (12) and a pressure-fluid source (16), the actuator (12) comprising a piston means (56, 66, 92) displaceable under the effect of the pressure-fluid and intended to actuate the receiver independently in response to an electrical control signal supplied to the valve mechanism (10).
Abstract:
A distribution apparatus of the invention comprises a distribution circuit whose passages of variable section are formed by the partial overlapping of holes of circular contour cut in a distribution element and longitudinal grooves cut in another distribution element.
Abstract:
A torque-amplifying hydraulic servo-mechanism of the kind including a rotary hydraulic motor and a hydraulic distributor, said motor being of the sliding vane type and the distributor of the "face", open center type. According to the invention, the rotor (50) of the hydraulic motor includes two diametrically opposite cylindrical surfaces (90) in contact with the stator bore and each extending over an arc equal to that between two adjacent vanes (24), and two interconnecting portions each having two flat faces (106, 108) interconnected by a cylindrical surface portion (104); and the number of vanes (94) is advantageously four times the number of said surfaces ( 90), that is eight. The servo-mechanism thus designed may be advantageously used in power steering systems for motor vehicles, and produces an output torque substantially constant irrespective of the relative position of the rotor and stator of the hydraulic motor.
Abstract:
The invention discloses a power-steering mechanism for an automotive vehicle, having a double acting actuator with two pressure chambers separated by an actuator piston. The actuator is connected both to the chassis of the vehicle and to a linkage associated with the direction controlling wheels of the vehicle. The pressure in the actuator chambers are controlled by a distributing valve operated by the steering wheel moved in either direction from a central, idle position. A reaction device adapted to create a return force biasing the steering wheel into its central position includes a circular cam eccentrically mounted on the rotating shaft of steering wheel and subjected to a thrust transmitted by a tappet. The tappet is projecting into a closed compartment to engage a reaction piston submitted to the pressure prevailing in a fluid accumulator. Two plungers are slidably mounted in the compartment and are submitted to the pressure prevailing in the actuator chambers. Finally stops are provided to limit motions of the plungers out of the closed compartment.
Abstract:
A pressure-regulating solenoid valve (100) for a hydraulic circuit for a braking system of a motor vehicle having wheel antilock structure. The hydraulic circuit has at least one pressurized fluid generator (300) connected to a pressure receiver (200) and to a reservoir (400) for retaining fluid at a low pressure. The solenoid valve (100) has an electrical coil (10) which interacts with two pole pieces (12,14), a sleeve structure (28,30) forming a magnetic body (26) which moves under the effect of an actuation force (O) generated by a magnetic field created by the electrical coil (10) and a distributor element (34). The distributor element (34) interacts with the sleeve structure (28,30) in order to command communication between a duct (98) connected to the pressure receiver (200) and a duct (94) connected to the reservoir (400) or a duct (96) connected to the pressure receiver (200). The solenoid valve (100) has at least one reaction chamber (80) which is permanently in communication with pressure chamber (200). The solenoid valve (100) reacts to a reaction force which is added to an actuation force (O) generated by the coil (10) and counter to a force (F) generated by a preloaded elastic means (46,85) on the movable body (26).