초록 ▼

The present disclosure provides a control system of a powered machine. The control system includes a hydraulic motor configured to drive a track system of the machine. The motor is operable with a variable displacement. A control valve is fluidly coupled to the motor. In addition, the control system

The present disclosure provides a control system of a powered machine. The control system includes a hydraulic motor configured to drive a track system of the machine. The motor is operable with a variable displacement. A control valve is fluidly coupled to the motor. In addition, the control system includes a controller and an electro-hydraulic valve disposed in electrical communication with the controller and fluid communication with the control valve. The electro-hydraulic valve receives a signal from the controller, and based on the signal, the electro-hydraulic valve hydraulically varies the start of control pressure of the motor.

대표청구항 ▼

1. A control system of a powered machine, the machine having an engine for producing power and a track system for moving along a surface, comprising: a hydraulic pump adapted to provide fluid pressure to the control system;a hydraulic motor configured to drive the track system, the motor being opera

1. A control system of a powered machine, the machine having an engine for producing power and a track system for moving along a surface, comprising: a hydraulic pump adapted to provide fluid pressure to the control system;a hydraulic motor configured to drive the track system, the motor being operable with a variable displacement between a minimum displacement and a maximum displacement;a control valve fluidly coupled to the motor along a pressure load line, where a load input received by the motor during operation transfers a load pressure from the motor to the control valve via the pressure load line;a controller; anda proportional electro-hydraulic valve disposed in electrical communication with the controller and fluid communication with the control valve, the proportional electro-hydraulic valve being operably controlled by the controller between a closed position and any one of a plurality of open positions to vary fluid pressure from the proportional electro-hydraulic valve to the control valve;wherein, the motor is operably controlled in a start of control pressure region defined by a first profile curve and a second profile curve, the first profile curve defined relative to travel slope and machine speed and including a first start of control pressure point and a first maximum displacement point, and the second profile curve defined relative to travel slope and machine speed and including a second start of control pressure point and a second maximum displacement point;wherein, a movement of the proportional electro-hydraulic valve induces a movement of the control valve to variably control motor operation at any location within the start of control pressure region;further wherein, the machine is operable at a first speed corresponding to the first and second start of control pressure points, and at a second speed corresponding to the first and second maximum displacement points, where the first speed is greater than the second speed. 2. The control system of claim 1, wherein the pump is fluidly coupled to the control valve when the proportional electro-hydraulic valve is disposed in at least one of its plurality of open positions. 3. The control system of claim 1, wherein the proportional electro-hydraulic valve is biased in a closed position. 4. The control system of claim 1, further comprising a spring for biasing the control valve to a first position, where in the first position the control valve fluidly controls the motor to minimum displacement. 5. The control system of claim 4, wherein the proportional electro-hydraulic valve sends a fluid pressure to the control valve, the fluid pressure and load pressure induce a pressure force against the control valve to vary the start of control pressure of the motor between its first start of control pressure and second start of control pressure. 6. The control system of claim 4, further comprising a motor actuator fluidly coupled to the control valve, where a movement of the control valve induces a corresponding movement of the motor actuator to vary the start of control pressure and displacement of the motor. 7. A method for varying the start of control pressure of a variable displacement hydraulic motor adapted to drive a track system of a machine along a ground surface, the machine including user controls for controlling the functionality of the machine, a controller in electrical communication with the user controls, a control valve biased in a first position by a spring having a fixed spring force, and a proportional electro-hydraulic valve electrically coupled to the controller and fluidly coupled to the control valve, the method comprising: sending an electrical signal to the proportional electro-hydraulic valve;moving the proportional electro-hydraulic valve from a substantially closed position to any one of a plurality of open positions;fluidly coupling the proportional electro-hydraulic valve and control valve to one another;controllably moving the control valve from the first position to any one of a plurality of control positions; andvarying the start of control pressure of the motor with the proportional electro-hydraulic valve between a first start of control pressure and a second start of control pressure, the first and second start of control pressures triggered at approximately the same motor displacement and machine travel speed but at different surface grades, where the first start of control pressure is triggered at a smaller surface grade than the second start of control pressure. 8. The method of claim 7, wherein the varying step comprises fluidly controlling a motor actuator. 9. The method of claim 7, further comprising: receiving an input from the user controls, the input related to a desired function of the machine; andoperably controlling the control valve based on the input by varying fluid pressure provided to the control valve through the proportional electro-hydraulic valve. 10. The method of claim 7, wherein the controllably moving step comprises: applying a hydraulic force to the control valve, the hydraulic force including a fluid pressure from the proportional electro-hydraulic valve and a load pressure from the motor;compressing the spring; andmoving the control valve to induce a change in motor displacement. 11. The method of claim 7, further comprising: providing the motor with a fixed setting for controlling motor displacement and a plurality of displacement profiles, each of the displacement profiles including a start of control pressure point and a maximum displacement point, where each start of control pressure point is a function of minimum motor displacement and machine travel, and each maximum displacement point is a function of maximum motor displacement and machine travel;controlling the motor according to one of the plurality of displacement profiles;sending a signal to override the fixed setting of the motor; andvariably adjusting the motor to operate according to a second of the plurality of displacement profiles. 12. A method of controlling a variable displacement hydraulic motor for driving a machine, the machine including operator controls for controlling the operation of the machine, a controller in electrical communication with the operator controls, a control valve biased in a first position and disposed in fluid communication with the motor, a pump, and a proportional electro-hydraulic valve electrically coupled to the controller and fluidly coupled to the control valve, the method comprising: receiving an input signal from the operator controls, where the input signal corresponds to a desired machine operation;sending an electrical signal to the proportional electro-hydraulic valve based on the input signal;moving the proportional electro-hydraulic valve between a substantially closed position and any one of a plurality of open positions;fluidly coupling the pump, the proportional electro-hydraulic valve and the control valve to one another when the proportional electro-hydraulic valve is disposed in any one of its plurality of open positions;controllably moving the control valve from the first position to a second position based on the electrical signal;controlling the motor within a start of control pressure region based on the desired machine operation, wherein the start of control pressure region is defined by a first profile curve, a second profile curve, a minimum motor displacement, and a maximum motor displacement, the first profile curve including a first start of control pressure point and a first maximum displacement point, and the second profile curve including a second start of control pressure point and a second maximum displacement point; andoperating the machine at a first speed corresponding to the first and second start of control pressure points at the minimum motor displacement, and at a second speed corresponding to the first and second maximum displacement points at the motor maximum displacement, where the first speed is greater than the second speed. 13. The method of claim 12, further comprising variably controlling minimum motor displacement at any point in the start of control pressure region between the first start of control pressure point and the second start of control pressure point. 14. The method of claim 12, further comprising variably controlling movement of the proportional electro-hydraulic valve to control motor operation at any location within the start of control pressure region. 15. The method of claim 12, further comprising: detecting the input signal as a command for an increase in machine speed;controlling movement of the proportional electro-hydraulic valve;increasing fluid pressure from the pump to the control valve through the proportional electro-hydraulic control valve; andcontrollably adjusting motor operation within the start of control pressure region to increase motor displacement. 16. The method of claim 12, further comprising continuously operating the motor at minimum displacement between the first start of control pressure point and the second start of control pressure point. 17. The method of claim 12, further comprising: controlling movement of the proportional electro-hydraulic control valve to reduce fluid pressure to the control valve;increasing motor displacement; andreducing a travel speed of the machine. 18. The method of claim 12, further comprising: receiving a load input by the motor during machine operation;transferring a load pressure from the motor to the control valve via a pressure load line; andcontrolling movement of the proportional electro-hydraulic valve between its closed position and any one of its plurality of open positions to vary fluid pressure from the proportional electro-hydraulic valve to the control valve in response to the load pressure. 19. The control system of claim 1, wherein the first and second start of control pressure points define a minimum motor displacement as a function of travel slope. 20. The control system of claim 1, wherein the motor is maintained at its minimum motor displacement between the first start of control pressure point and the second start of control pressure point.