Hydraulic system for suppressing oscillation in heavy equipment
AssigneeCase Corporation
InventorsDennis Heyne, Richard J. Lech, Eric Sharkness, David W. Swaim, Guy T. Stoever, Ian MacLeod
Life of this patent
Estimating the term…
Abstract
The invention provides a system for regulating pressure equalization in hydraulic mechanisms to suppress oscillation in heavy equipment. The system includes a first and second hydraulic lines, a crossover valve in communication with each of the first and second hydraulic lines, a timing system in communication with the crossover valve, and a motion detector in communication with a heavy equipment component. The motion detector senses a linkage motion and operatively opens the crossover valve, which remains open as directed by the timing system.
Claims51
A swing damping valve for a backhoe, the backhoe having at least one swing cylinder having an extend and a retract port for swinging a backhoe boom in two directions about a substantially vertical axis, and a directional control valve coupled between a hydraulic tank and a hydraulic supply and configured to provide fluid to the extend and retract ports of the at least one swing cylinder through an extend port and a retract port line wherein the valve comprises:
- a valve body having a first port configured to be coupled to the extend port of the directional control valve, a second port configured to be coupled to the retract port of the directional control valve, a third port configured to be coupled to move the swing cylinder in a first of said two directions and a fourth port configured to be coupled to move the swing cylinder in a second of said two directions, wherein the valve body further defines a first fluid flow conduit configured to permit bidirectional flow between the first and third port, and a second conduit configured to permit bi-directional flow between the second and fourth ports, and wherein the valve body further defines a third conduit coupling the first and second conduits;
- and
- a movable cross-over valve element disposed in the valve body and in the flow path defined by the third conduit to selectively block flow through the third conduit in response to a difference in pressure between the first and second conduits.
A swing damping valve for damping oscillations in an articulated boom that is pivotable about a vertical axis by at least one hydraulic actuator controlled by at least one flow control valve, wherein the valve comprises:
- a valve body having a first valve body port configured to be coupled to a first port of the at least one flow control valve, a second valve body port configured to be coupled to a second port of the at least one flow control valve, a third valve body port configured to be coupled to move the at least one hydraulic actuator in a first direction and a fourth valve body port configured to be coupled to move of the at least one hydraulic actuator in a second direction, wherein the valve body further defines a first fluid flow conduit configured to provide substantially all the flow between the first and third valve body ports and a second fluid flow conduit configured to provide substantially all the flow between the second and fourth valve body ports, and further wherein the valve body further defines a third hydraulic fluid line coupling the first and second conduits;
- and
- a movable cross-over valve element disposed in the valve body and in the flow path defined by the third hydraulic fluid line to selectively block flow through the third conduit in response to a difference in pressure between the first and second conduits, wherein the movable cross-over element is responsive to hydraulic pressure flows in the first and second conduits to open and permit a quantity of fluid sufficient to reduce oscillation of the articulated boom to pass through.
A swing damping valve for damping oscillations in an articulated boom that is pivotable about a vertical axis by at least one hydraulic actuator controlled by at least one flow control valve, wherein the valve comprises:
- (a) a valve body having
- (i) a first port-providing surface;
- (ii) a first valve body port configured to be coupled to a first port of the at least one flow control valve and disposed in the first port-providing surface;
- (iii) a second valve body port configured to be coupled to a second port of the at least one flow control valve and disposed in the first port-providing surface;
- (iv) a second port-providing surface;
- (v) a third valve body port configured to be coupled to move the at least one hydraulic actuator in a first direction and disposed in the second port providing surface;
- and
- (vi) a fourth valve body port configured to be coupled to move the at least one hydraulic actuator in a second direction and disposed in the second port-providing surface, wherein the valve body defines a first internal fluid flow conduit configured to provide substantially all the flow between the first and third valve body ports and further defines a second internal fluid flow conduit configured to provide substantially all the flow between the second and fourth valve body ports, and further defines a third internal hydraulic conduit that couples the first and second conduits inside the valve body;
- and
- (b) a movable cross-over valve element disposed in the valve body and in the flow path defined by the third conduit to selectively block flow through the third conduit in response to a difference in pressure between the first and second conduits, wherein the movable cross-over element is responsive to hydraulic pressure flows in the first and second conduits to responsively open and permit a quantity of fluid sufficient to damp the swinging of the articulated boom.
Dependencies are inferred from the claim text.