초록 ▼

A hydraulic control system for a machine is disclosed. The hydraulic control system may have a tank, a pump configured to draw fluid from the tank and pressurize the fluid, a swing motor configured to receive the pressurized fluid and swing a body of the machine relative to an undercarriage, and a t

A hydraulic control system for a machine is disclosed. The hydraulic control system may have a tank, a pump configured to draw fluid from the tank and pressurize the fluid, a swing motor configured to receive the pressurized fluid and swing a body of the machine relative to an undercarriage, and a tool actuator configured to receive the pressurized fluid and move a tool relative to the body. The hydraulic control system may also have an energy recovery device configured to convert hydraulic energy to mechanical energy, a first accumulator configured to store waste fluid received from the swing motor, and a second accumulator configured to store waste fluid received from the tool actuator. Stored waste fluid from at least one of the first and second accumulators may be selectively discharged into the energy recovery device.

대표청구항 ▼

1. A hydraulic control system for a machine, comprising: a tank;at least one pump configured to draw fluid from the tank and pressurize the fluid;a swing motor configured to receive the pressurized fluid and swing a body of the machine relative to an undercarriage;a tool actuator configured to recei

1. A hydraulic control system for a machine, comprising: a tank;at least one pump configured to draw fluid from the tank and pressurize the fluid;a swing motor configured to receive the pressurized fluid and swing a body of the machine relative to an undercarriage;a tool actuator configured to receive the pressurized fluid and move a tool relative to the body;an energy recovery device configured to convert hydraulic energy to mechanical energy;a first accumulator configured to store waste fluid received from the swing motor; anda second accumulator configured to store waste fluid received from the tool actuator,wherein stored waste fluid from at least one of the first and second accumulators is selectively discharged into the energy recovery device. 2. The hydraulic control system of claim 1, wherein both the first and second accumulators are configured to selectively discharge stored waste fluid into the energy recovery device. 3. The hydraulic control system of claim 2, further including a discharge valve disposed between the energy recovery device and the first and second accumulators, the discharge valve having a valve element movable between a first position at which waste fluid from the first accumulator is allowed to pass into the energy recovery device, and a second position at which waste fluid from the second accumulator is allowed to pass into the energy recovery device. 4. The hydraulic control system of claim 3, wherein the discharge valve is a dual-solenoid valve that is spring-biased to a third position at which fluid flow through the discharge valve is inhibited. 5. The hydraulic control system of claim 1, wherein the first accumulator is configured to selectively discharge stored waste fluid received from the swing motor back to the swing motor. 6. The hydraulic control system of claim 1, wherein the energy recovery device is mechanically connected to a power source of the machine. 7. The hydraulic control system of claim 6, wherein the energy recovery device is mechanically connected to the power source by way of the at least one pump. 8. The hydraulic control system of claim 1, further including a swing selector valve configured to selectively pass fluid from a side of the swing motor having a higher pressure. 9. The hydraulic control system of claim 1, further including: a first charge valve disposed between the swing motor and the first accumulator, the first charge valve being solenoid operated to move from a flow-blocking position to a flow-passing position; anda second charge valve disposed between the tool actuator and the second accumulator, the second charge valve being solenoid operated to move from a flow-blocking position to a flow-passing position. 10. The hydraulic control system of claim 9, further including at least one pressure sensor associated with at least one of the first and second accumulators, wherein movement of at least one of the first and second charge valves is based on a signal from the at least one pressure sensor. 11. The hydraulic control system of claim 1, wherein the at least one pump includes: a first pump configured to pressurize fluid directed to the swing motor via a first circuit; anda second pump configured to pressurize fluid directed to the tool actuator via a second circuit. 12. The hydraulic control system of claim 1, further including: a bypass passage fluidly connecting an outlet of the energy storage device to an inlet of the energy storage device; anda check valve disposed within the bypass passage. 13. A method of recovering energy for a machine, comprising: pressurizing a fluid;utilizing the pressurized fluid to swing a body of the machine relative to an undercarriage;utilizing the pressurized fluid to move a tool relative to the body;storing first pressurized waste fluid used to swing the body; andstoring second pressurized waste fluid used to move the tool; andselectively converting hydraulic energy from at least one of the stored first pressurized waste fluid and the stored second pressurized waste fluid to mechanical energy used to pressurize the fluid. 14. The method of claim 13, wherein selectively converting hydraulic energy includes selectively converting hydraulic energy from both the first pressurized waste fluid and the second pressurized waste fluid. 15. The method of claim 14, further including selectively allowing hydraulic energy from only one of the first pressurized waste fluid and the second pressurized waste fluid to be converted to mechanical energy used to pressurize the fluid at a given time. 16. The method of claim 15, further including selectively inhibiting hydraulic energy from either of the first pressurized waste fluid and the second pressurized waste fluid from being converted to mechanical energy used to pressurized the fluid. 17. The method of claim 13, further including discharging a store of the first pressurized waste fluid to brake swinging of the body. 18. The method of claim 13, wherein storing the first pressurized waste fluid includes storing only a higher-pressure one of two flows of fluid associated with swinging of the body. 19. The method of claim 13, further including sensing a stored pressure of at least one of the first pressurized waste fluid and the second pressurized waste fluid, wherein the selectively converting hydraulic energy is based on the stored pressure. 20. A machine, comprising: an engine an undercarriage drive by the engine;a body;a swing motor configured to swing the body relative to the undercarriage;a tool;a tool actuator configured to move the tool relative to the body;a tank;a first pump driven by the engine to draw fluid from the tank, pressurize the fluid, and direct the pressurized fluid to the swing motor via a first circuit;a second pump driven by the engine to draw fluid from the tank, pressurize the fluid, and direct the pressurized fluid to the tool;an energy recovery device connected to one of the first and second pumps and configured to convert hydraulic energy to mechanical energy;a first accumulator configured to store waste fluid received from the swing motor;a first charge valve disposed between the swing motor and the first accumulator, the first charge valve being solenoid operated to move from a flow-blocking position to a flow-passing position;a second accumulator configured to store waste fluid received from the tool actuator;a second charge valve disposed between the tool actuator and the second accumulator, the second charge valve being solenoid operated to move from a flow-blocking position to a flow-passing position; andat least one pressure sensor associated with at least one of the first and second accumulators,wherein: stored waste fluid from at least one of the first and second accumulators is selectively discharged into the energy recovery device to drive the engine via the one of the first and second pumps; andmovement of at least one of the first and second charge valves is based on a signal from the at least one pressure sensor.