摘要:
Hydraulic control unit, in particular for the folding roof of a vehicle, comprising a reservoir for hydraulic fluid, a pump for drawing hydraulic fluid out of the reservoir and provided with a delivery port for delivering compressed hydraulic fluid, and also at least one first hydraulic actuator of the double-acting type with a first and a second variable working chamber, which working chambers are separated by a piston and are provided with a first and a second connection respectively for supplying hydraulic fluid to said working chambers, further comprising a control valve assembly with a first exit port and a second exit port, which are connected respectively to the first and the second connection of the first actuator, for controlling the movements of the first actuator. The control valve assembly comprises one or more operable control valves and is designed for selectively connecting one of the two or both exit ports thereof to the delivery port of the pump or the reservoir. In addition, an AND valve is provided, having a first and a second entry port and an exit port. The entry ports of the AND valve are connected here respectively to the first and the second exit port of the control valve assembly. The exit port of the AND valve forms a third exit port for controlling one or more following actuators of the hydraulic control unit.
摘要:
A valve bank has a coil pack assembly with multiple solenoid coils bound to one another by a single resin body. An L-shaped magnetic (but not magnetized) bracket is also bound within the body and extends between upper pole pieces of the valves and the manifold in which the valves are mounted. A retainer plate holds the valves in the manifold, and helps complete the magnetic flux path circuit from the manifold end of the bracket to the lower pole pieces of the valves. A spring clip helps position the manifold end of the bracket close to the retainer plate. A circuit board for individually energizing the coils is also potted within the resin body.
摘要:
A vehicle cab suspension unit has a foundation which is secured to an outer rail of the frame of the vehicle and pivotally connects one end of a track arm. The other end of the track arm is supported above the foundation by an air spring, and a cab support yoke is pivotally connected between the ends of the track arm so as to support and secure the cab at a position along the track arm between its ends. Shock absorbers are provided between the foundation and the cab support yoke on both sides of the track arm. A height control valve maintains the height of the suspension unit and elastomeric snubbers on the foundation provide limits to the range of travel of the unit.
摘要:
A cylindrical ferrule having internal threads is joined to a fiberglass fish tape having an outside diameter smaller than the inside diameter of the internal threads. An adhesive between the fish tape and the threads bond the fiberglass and fills voids between the fish tape and threads. The cured adhesive bonded to the fish tape acts on bearing surfaces of the threads to resist loosening and pulling away from the ferrule.
摘要:
An apparatus for absorbing vibrations in a structural member, such as in an aircraft fuselage, has a mounting member for attaching to the structural member. Two masses are coupled in a cantilevered manner to the mounting member by a plurality of flexible rigid members, such as rods or plates, which act as a spring that allows the masses to vibrate with respect to the mounting member. The spring-mass assembly has a resonant frequency that matches the frequency of the vibrations in the structural member. A mechanism, connected between the two masses, exerts a variable force on the plurality of rigid members to compensate for changes in their stiffness due to changes in temperature and thereby maintain the resonant frequency substantially constant. Preferably the mechanism includes a bimetallic element that has a shape which changes with temperature variation to produce the variable force.
摘要:
A hydraulic circuit for controlling a plurality of hydraulic motors of a machine has a reversible pump with its suction/pressure ports connected to the inputs of an OR-valve is connected to the input of at least one 3/2 electro-valve, which has its output connected to the inputs of the AND-valves which are not connected to the pump. The AND-valve outputs and the suction/pressure ports are used individually or in combination to control the hydraulic motors.
摘要:
A hydraulic control valve has a two position body shifted by rotation. The shaft of the valve body carries a drive wheel segment extending through an arc that corresponds to the shift angle of the valve. A spring is provided to bias, at least in the final stage of rotation in either direction, the wheel segment in the opposite direction of rotation. This enables the valve body to be positioned into the other position in a reliable manner.
摘要:
A system for tightening a threaded fastener with a hydraulic wrench has a pumping unit which measures parameters representative of the torque applied to the fastener and the angle of advance of the fastener, remote from the wrench. The pump measures pressure as a parameter representative of torque and measures, pump speed as a parameter which is processed so as to be representative of the angle of advance of the fastener. A ratchet-type hydraulic wrench is used, and the pressure versus angle data produced in tightening a fastener is manipulated to discard irrelevant portions and smooth relevant portions to provide data representative of torque and angle during the tightening process from which to determine a final stopping parameter for terminating tightening. The system also has a calibration fixture for determining the volumetric rate of angle advance for a given wrench. Any tightening methodology dependent upon angle may be used to practice the invention, or the invention may be applied to monitor the tightening process.