摘要:
A hydraulic circuit capable of both a regeneration mode of operation and a full force mode of operation includes a poppet valve controlled by a control valve operating in conjunction with a shuttle valve. The opening of the poppet valve enables the regeneration mode of operation, and the closing of the poppet valve enables the full force mode of operation.
摘要:
A hydraulic system for a mobile working machine includes a hydraulic pump, a steering valve, a steering actuator controlled by the steering valve, a first hydraulic line which extends between the hydraulic pump and the steering valve, and a hydraulic storage unit which is connected with the first hydraulic line via a second hydraulic line). So as to optimize a pressure state for the hydraulic system, a throttle connected in parallel with a check valve is located in the second hydraulic line. The check valve permits one-way fluid flow in a direction away from the hydraulic storage unit.
摘要:
A suspension device is for at least one drive part (10) that is to be cushioned. The drive part can be connected to an accumulator device (12) by a first valve unit (28) and to a tank connection (46) by a second valve unit (34) to transport fluid. The device is provided with a pressure compensation device (50), which when actuated compares the respective prevailing pressures in the drive part (10) and the accumulator device (12) to generate a common pressure level. This comparison permits the pressure level to be rapidly compensated in advance when the actual suspension is enabled in the form of the accumulator device, in such a way that the suspension pressure employed exactly matches the pressure of the respective drive part in the form of a hydraulic or working cylinder that prevails in the later as a result of the preceding load actuation operations.
摘要:
The invention relates to a suspension device for at least one drive part (10) that is to be cushioned. Said part can be connected to an accumulator device (12) by means of a first valve unit (28) and to a tank connection (46) by means of a second valve unit (34) in order to transport fluid. The device is provided with a pressure compensation device (50), which when actuated compares the respective prevailing pressures in the drive part (10) and the accumulator device (12) in order to generate a common pressure level. This permits the pressure level to be rapidly compensated in advance when the actual suspension is enabled in the form of the accumulator device, in such a way that the suspension pressure employed exactly matches the pressure of the respective drive part in the form of a hydraulic or working cylinder that prevails in the latter as a result of the preceding load actuation operations.
摘要:
Disclosed is a flow control apparatus for construction heavy equipment capable of maintaining constant set flow rate regardless of changes in load pressure and pump pressure. The flow control apparatus is composed of a control valve, a flow control valve, and a load check valve. The control valve has a parallel passage, a housing provided with a first load passage and a second load passage, and a control spool provided to be movable in the housing. The flow control valve having a logic check valve provided to be openable between the first load passage and the parallel passage, and a logic control valve controlling a flow rate supplied to a back pressure chamber of the logic check valve. The load check valve is provided between the second load passage and the parallel passage to restrict backflow from the second hydraulic cylinder.
摘要:
The control valve apparatus holds a seat valve member in a position seated on a valve seat to thereby prevent a backward flow even if the pressure in the inlet chamber side becomes lower than the pressure in the outlet chamber side. With a pilot control valve member is in a closed state, when the pressure in the inlet chamber is higher, a pressurized medium is introduced to the control pressure chamber via a first valve unit and is cut off from the outlet chamber by a second valve unit. When the pressure in the outlet chamber is higher, the pressurized medium is introduced to the control pressure chamber via the second valve unit and is cut off from the outlet chamber by the first valve unit.
摘要:
High frequency shock absorber/accelerator built in at any or both end of conventional air cylinder that includes piston moving axially inside cylinder body and sealed against inner surface of body by sealing structure. Cylinder piston rod protrudes outside thru cylinder front-end block Shock absorber/accelerator comprises piston with sealing structures moving axially in inner chamber, which communicates with outer chamber thru aperture(s). Air cylinder piston meets the protruded rod of the shock absorber/accelerator piston and starts to move it thus pushing volume of compressed air through provided aperture from inner chamber to outer chamber. Piston sealing structures seal air coming through the aperture thereby isolating compressed air in the outer chamber from the inner chamber. Compressed air coming through the open venting valve forces pistons to move in opposite direction. Then, shock absorber/accelerator aperture opens and compressed air rushes back from the outer to the inner chamber for powerful acceleration.
摘要:
A cylinder apparatus with a capability of detecting a piston position includes a cylinder, a throttling valve, a positive limit and a pressure switch. A piston is movably mounted in the cylinder. A piston rod with an outside end protruding out of the cylinder is attached to the piston and adapted to push an object. The cylinder is connected to a pump with pipes. The throttling valve and the pressure switch are connected to the pipes, and the pressure switch is installed between the cylinder and the throttling valve. Consequently, when the pump starts pumping, the piston rod pushes the object to abut the positive limit. The stopped movement of the piston rod will change the pressure in the cylinder that triggers the pressure switch to send a signal to a controlling host to stop the pump.
摘要:
A mine door installation has a frame installed in a mine passageway. At least one door leaf is mounted on the frame for swinging movement between open and closed positions. Movement of the door leaf is powered by a pneumatic actuator. The door installation also has a hydraulic checking system for controlling the speed of the door leaf as it moves back and forth between open and closed positions. A pneumatically-powered control system may be provided to control the door installation. The pneumatic control system may comprise a calibrated vent to shorten the delay in the response of the door leaf to direction from the control system to stop moving. The pneumatic control system may also comprise a limit valve to prevent the door installation from opening when a second door installation is open, thereby preventing both door installations in an air lock from being open at the same time.
摘要:
A hydraulic actuating device for moving an object, for example for a retractable hard-top of a convertible car. The actuating device comprises a reservoir for hydraulic fluid and a pump for delivering pressurized hydraulic fluid. Furthermore, the device comprises a double-acting hydraulic actuator, the first connection of the actuator being in communication with an associated throttling assembly which is designed to provide, for hydraulic fluid passing through the first connection, either an optionally controllable throttling or a clear passage opening, which is larger than the throttling opening, as a function of a switching parameter. The throttling assembly, which is in communication with the first connection of the actuator, has a pressure-detection means for detecting the hydraulic pressure in the second working chamber, which pressure-detection means has associated with it a predetermined switching pressure. The throttling assembly is designed in such a manner thatnullwhen pressurized hydraulic fluid is being supplied to the said second working chambernullthe clear passage opening is active if the detected pressure in the said second working chamber is above the switching pressure and that the throttling is active if the detected second working chamber hydraulivc pressure in the said second working chamber is below the switching pressure.