Abstract:
A master cylinder (10) for a hydraulic vehicle brake system has a housing (34) and a bore (36) which is disposed therein and in which a hollow cylindrical primary piston (38), which acts on a pressure chamber (40), is guided in a sealing and axially displaceable manner. An axially displaceable, hollow cylindrical auxiliary piston (42) is accommodated in the primary piston (38), into which piston (42) an actuating piston (46) projects, which piston (46) is adapted to be actuated by means of an input member (24), is is guided in a sealing and displaceable manner in the auxiliary piston (42) and is resiliently preloaded away from the latter at least during braking. The actuating piston (46) has a first hydraulically active diameter (D1) and the auxiliary piston (42) has a second hydraulically active diameter (D2). The auxiliary piston (42) is rigidly coupled to the actuating piston (46) after covering a determined distance against its resilient preload. In order to achieve a brake assistant function, a shift piston (58) is disposed in the primary piston (38), which shift piston is resiliently preloaded in the direction of the pressure chamber (40) and is adapted to be displaced axially relative to the auxiliary piston (42). The resilient preload of the shift piston (58) corresponds to a predetermined pressure level in the pressure chamber (40), and the shift piston (58) is displaced relative to the auxiliary piston (42) against the spring preload once this pressure level has been exceeded, whereby a valve (68) closes the fluid connection between the second hydraulically active diameter (D2) of the auxiliary piston (42) and the pressure chamber (40).
Abstract:
A hydraulic master cylinder for vehicle has: a cylinder main body; a sleeve; a plurality of seal rings; a plug, a lid member comprising the sleeve and the plug; and a piston inserted into the cylinder bore so as to form a hydraulic pressure chamber between the piston and the lid member; wherein the sleeve is inserted into the cylinder main body with an open end thereof being made to face an interior of the cylinder main body so as to dispose the seal rings between a circumferential wall of the cylinder bore and the sleeve and in such a manner that the seal rings hold the outlet port therebetween, and the plug is fixedly threaded in the opening at the one end so as to prevent the dislocation of the sleeve.
Abstract:
In a hydraulic system (1) for motor vehicles in particular, comprising a master cylinder (4), a slave cylinder (5) and a hydraulic medium line (15) connecting the two, the flexibility and hydraulic rigidity are improved by the fact that the hydraulic medium line (15) includes at least two sections (16, 17, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30) having different wall thicknesses. A feeder line or hydraulic medium line with an inert inner material layer and a transfer device with two interconnected pipes running in parallel are also disclosed.
Abstract:
The piston in the master cylinder of a hydraulic system of the kind that is used particularly in motor vehicles is made of a duroplastic polymer material.
Abstract:
A master cylinder and booster device for a motor vehicle braking system, in which the master cylinder (10) and the booster (12) are assembled to form a one-piece entity comprising a small reservoir (20) of brake fluid mounted on the master cylinder (10) and connected by a flexible duct (22) to a separate brake fluid reservoir (24) secured temporarily to the entity (10-12) for the purposes of delivering it to a motor vehicle manufacturer.
Abstract:
A brake apparatus and method utilize an electric power brake booster for operating a push rod actuated hydraulic master cylinder. The existing vehicle electrical system provides electric power for the power brake booster, thus eliminating the need for engine driven or auxiliary pressure/vacuum sources. The electric power brake booster includes an electrically powered actuator having an output shaft adapted for operative connection to the master cylinder, and an input for receipt of a signal indicative of force applied to the push rod. The electrically powered actuator augments the force applied to the push rod in response to the signal indicative of the force applied to the push rod. The booster may include a sensor for sensing force applied to the push rod and generating the signal indicative of the force applied to the push rod.
Abstract:
A servoactuator (20) is operatively arranged to control the movement of an output member (21) in either of two directions in response to a command signal. The servoactuator includes an electric motor (25) having a rotatable output shaft (26); a motor controller (25) arranged to provide a drive current to the motor for controllably rotating the output shaft; a first transmission mechanism (34) operatively arranged to displace the output member in either direction at a nominal first ratio with respect to the motor output shaft; a hydrostatic second transmission mechanism (35) operatively arranged to displace the output member in either direction at a nominal second ratio with respect to the motor output shaft; a transfer mechanism (36) operatively arranged to selectively couple the motor output shaft to the output member either through the first transmission mechanism to impart a high-speed low-force drive to the output member, or through the second transmission mechanism to impart a low-speed high-force drive to the output member; at least one feedback transducer (29, 32) capable of measuring one of the force, displacement or velocity of the output member; and a servo control loop (30, 33) closed about the motor, controller, transmission mechanisms, transfer mechanism, feedback transducer and output member for selectively controlling at least one of the position, velocity or force of the output member as a function of the command signal.
Abstract:
A master cylinder assembly including a boost assembly. The hydraulic master cylinder includes a cylinder defining an elongated bore, a piston slidably positioned in said bore, inlet means in the cylinder for admitting hydraulic fluid into the bore from a reservoir, and an outlet fitting in said cylinder communicating with said bore and operative to convey hydraulic fluid out of the bore for delivery to a brake device in response to linear movement of the piston in the bore. The boost assembly includes an electric motor. A hollow ball nut and screw assembly is operably connected to the motor. A screw of the ball nut and screw assembly is positioned to advance the piston in response to actuation of the motor. An input rod extending through the screw includes a first end positioned to receive a brake input force and a second end positioned to advance the piston independently from the screw. The assembly further includes sensing and control means to sense the brake input force and control the motor responsive to the brake input force.
Abstract:
A servoactuator (20) is operatively arranged to control the movement of an output member (21) in either of two directions in response to a command signal. The servoactuator includes an electric motor (25) having a rotatable output shaft (26); a motor controller (25) arranged to provide a drive current to the motor for controllably rotating the output shaft; a first transmission mechanism (34) operatively arranged to displace the output member in either direction at a nominal first ratio with respect to the motor output shaft; a hydrostatic second transmission mechanism (35) operatively arranged to displace the output member in either direction at a nominal second ratio with respect to the motor output shaft; a transfer mechanism (36) operatively arranged to selectively couple the motor output shaft to the output member either through the first transmission mechanism to impart a high-speed low-force drive to the output member, or through the second transmission mechanism to impart a low-speed high-force drive to the output member; at least one feedback transducer (29, 32) capable of measuring one of the force, displacement or velocity of the output member; and a servo control loop (30, 33) closed about the motor, controller, transmission mechanisms, transfer mechanism, feedback transducer and output member for selectively controlling at least one of the position, velocity or force of the output member as a function of the command signal.
Abstract:
The present invention relates to a hydraulic system, in particular for motor vehicles, including a master cylinder having a housing, a piston which is axially movably disposed therein, which bounds a pressure chamber filled with a hydraulic fluid, and which, upon actuation of the master cylinder, is axially moved by a piston rod acting upon the piston, thereby pressurizing the hydraulic fluid; further including a slave cylinder and a pressure-medium line connecting the cylinders; the master cylinder having an adapter for detachable connection to the pressure-medium line. The objective of improving the connection between the pressure-medium line and the adapter is achieved in that the adapter includes a sleeve made of a metal.