A multi-degree-of-freedom active compensation crane hydraulic system

Abstract

A multi-degree-of-freedom active compensation crane hydraulic system includes an oil tank, a main pump assembly, a slewing coupling, a slewing balance valve group, a main boom luffing balance valve group, a folding boom luffing balance valve group, and an oil inlet coupling. The oil outlet of the oil tank is connected to the oil inlet of the main pump assembly, and an electric motor is connected to the main pump assembly. The main pump assembly includes a main pump, a second main pump, and a control pump. The oil outlet of the oil tank is connected to the oil inlets of the first main pump, the second main pump, and the control pump, respectively. The oil outlet of the first main pump is connected to the oil inlet of the oil inlet coupling M and the oil inlet of the slewing coupling B. This design transmits displacement signals to a controller integrated with horizontal servo valves for Y-direction servo control, enabling rapid movement following the target. A swing servo valve group is used for active compensation in the X-direction, and a first-stage vertical telescopic servo valve group and a second-stage vertical telescopic servo valve group are used for active compensation in the Z-direction, achieving multi-degree-of-freedom motion grasping.

Description

Technical Field

[0001] This invention relates to an improvement in crane hydraulic system technology, belonging to the field of active compensation crane hydraulics, and particularly to a multi-degree-of-freedom active compensation crane hydraulic system. Background Technology

[0002] The complex marine environment necessitates the use of cranes and robotic arms on ship decks during favorable weather conditions to grasp targets on the sea surface. When grasping precision targets, cranes typically require active compensation functions to minimize cargo movement. This involves the winch automatically retracting or extending the wire rope, or the hydraulic cylinder automatically extending or retracting the piston rod to counteract wave-induced motion, reducing relative movement with the target and improving the safety of cargo and personnel. However, the active compensation function of most cranes only compensates for vertical motion; other directional movements still require manual adjustment and control, resulting in slow response and low precision. Consequently, they cannot quickly and accurately follow the multi-degree-of-freedom movements of targets when grasping them on the sea surface.

[0003] Chinese patent application CN 201710942281.6, filed on October 11, 2017, discloses a hydraulic cylinder-type semi-active heave compensation device for a crane, used on a deep-water crane. It includes a passive compensation system, an active compensation system, and a hydraulic cylinder pulley system. This invention installs two parallel pulley sets at one end of the piston rod extension, increasing the compensation capacity fourfold and reducing the compensation speed to one-quarter of its original speed, thus reducing the impact caused by excessive speed. In the passive compensation method, the rod chamber and rodless chamber of the passive compensation cylinder are connected via oil pipes. The rodless chamber of the passive compensation cylinder is connected to a gas cylinder and an air pressurization system to compensate for most of the heave displacement. In the active compensation method, a tension sensor is placed at the location along the cable, transmitting the analog signal of the cable tension change to a controller. The controller then controls the piston rod movement of the active compensation cylinder by controlling the valve core of the electro-hydraulic proportional directional valve, achieving final precise compensation. However, the prior art does not address the problem of multi-degree-of-freedom motion grasping.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this patent application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem that existing technologies cannot perform grasping movements in multiple degrees of freedom, and to provide a multi-degree-of-freedom active compensation crane hydraulic system that can perform grasping movements in multiple degrees of freedom.

[0006] To achieve the above objectives, the technical solution of the present invention is: a multi-degree-of-freedom active compensation crane hydraulic system, the multi-degree-of-freedom active compensation crane hydraulic system including an oil tank, a main pump assembly, a slewing coupling, a slewing balance valve group, a main boom luffing balance valve group, a folding boom luffing balance valve group, and an oil inlet coupling;

[0007] The oil tank outlet is connected to the main pump assembly inlet, and the motor is connected to the main pump assembly. The main pump assembly includes a main pump, a second main pump, and a control pump. The oil tank outlet is connected to the inlet of the first main pump, the inlet of the second main pump, and the inlet of the control pump, respectively. The oil tank outlet is connected to the inlet of the oil inlet coupling, the inlet of the slewing coupling B, the inlet of the main boom load coupling, and the inlet of the boom luffing coupling.

[0008] The A port of the slewing coupling is connected to the E port of the slewing balance valve group, the B port of the slewing coupling is connected to the E port of the slewing balance valve group, the E port of the slewing balance valve group is connected to the slewing motor, the E port of the slewing balance valve group is connected to the slewing motor, and the E port of the slewing balance valve group is connected to the oil tank.

[0009] The A port of the main boom load connection is connected to the F port of the main boom luffing balance valve group, the B port of the main boom load connection is connected to the F port of the main boom luffing balance valve group, the F port of the main boom luffing balance valve group is connected to the rodless chamber of the main boom luffing hydraulic cylinder, and the F port of the main boom luffing balance valve group is connected to the rod chamber of the main boom luffing hydraulic cylinder.

[0010] The A port of the articulated boom luffing coupling is connected to the G port of the articulated boom luffing balance valve group, the B port of the articulated boom luffing coupling is connected to the G port of the articulated boom luffing balance valve group, the G port of the articulated boom luffing balance valve group is connected to the rodless chamber of the articulated boom luffing hydraulic cylinder, and the G port of the articulated boom luffing balance valve group is connected to the rod chamber of the articulated boom luffing hydraulic cylinder.

[0011] The T-ports of the oil inlet, slewing, main boom load, and boom luffing are all connected to the oil tank.

[0012] The two main pumps are connected to the P port of the electromagnetic on / off valve group, the P port of the electromagnetic on / off valve group is connected to the P port of the horizontal servo valve group, the P port of the electromagnetic on / off valve group is connected to the P port of the swing servo valve group, the P port of the electromagnetic on / off valve group is connected to the P port of the first-stage vertical telescopic servo valve group, and the P port of the electromagnetic on / off valve group is connected to the P port of the second-stage vertical telescopic servo valve group.

[0013] The horizontal servo valve group has the same structure as the swing servo valve group, and the T port of the horizontal servo valve group is connected to the oil tank.

[0014] The structure of the first-stage vertical telescopic servo valve group is the same as that of the second-stage vertical telescopic servo valve group, and the T-port of the first-stage vertical telescopic servo valve group is connected to the oil tank.

[0015] The A port of the horizontal servo valve group is connected to the rodless chamber of the horizontal telescopic hydraulic cylinder, the B port of the horizontal servo valve group is connected to the rod chamber of the horizontal telescopic hydraulic cylinder, the A port of the first-stage vertical telescopic servo valve group is connected to the rodless chamber of the first-stage vertical telescopic hydraulic cylinder, and the B port of the first-stage vertical telescopic servo valve group is connected to the rod chamber of the first-stage vertical telescopic hydraulic cylinder.

[0016] The R port of the horizontal servo valve group is connected to the control pump, the R port of the first-stage vertical telescopic servo valve group is connected to the control pump, the L port of the horizontal servo valve group is connected to the oil tank, and the L port of the first-stage vertical telescopic servo valve group is connected to the oil tank.

[0017] The oil inlet assembly includes a main relief valve, a sequence valve, a control oil pressure reducing valve, and a control oil relief valve. The main relief valve, the sequence valve, the control oil pressure reducing valve, and the control oil relief valve are connected to each other, and the control oil relief valve is connected to the rotary assembly B.

[0018] The slewing coupling, main boom load coupling, and boom luffing coupling have the same structure. The slewing coupling includes a first shuttle valve, a proportional directional valve, and a second shuttle valve. The first main pump is connected to the P port of the proportional directional valve, the T port of the proportional directional valve is connected to the oil tank, the B port of the proportional directional valve is connected to the B port of the second shuttle valve, the A port of the proportional directional valve is connected to the A port of the second shuttle valve, the C port of the second shuttle valve is connected to the A port of the first shuttle valve, the C port of the first shuttle valve is connected to the LS port of the first main pump, the B port of the first shuttle valve is connected to the C port of the main boom load coupling, and the T port of the proportional directional valve is connected to the E port of the slewing balance valve group and the E port of the slewing balance valve group, respectively.

[0019] A load-sensitive relief valve and a second load-sensitive relief valve are installed between the oil circuits of the first shuttle valve and the second shuttle valve. Port A of the first shuttle valve is connected to port P of the proportional directional valve via a differential pressure compensator. A replenishing oil check valve is installed on the oil circuit between port A and port T of the proportional directional valve. Two replenishing oil check valves are installed on the oil circuit between port B and port T of the proportional directional valve.

[0020] The rotary balance valve assembly includes a rotary shuttle valve and a hydraulic directional valve. The T port of the proportional directional valve is connected to the A port and B port of the rotary shuttle valve, respectively. The C port of the rotary shuttle valve is connected to the oil inlet of the hydraulic directional valve. The oil outlet of the hydraulic directional valve is connected to the rotary brake. The oil outlet of the hydraulic directional valve is connected to the oil tank. The rotary brake is mounted on the rotary motor. The A port of the rotary shuttle valve is connected to the A port of a rotary balance valve. The B port of the rotary balance valve is connected to the rotary motor. The B port of the rotary shuttle valve is connected to the A port of a second rotary balance valve. The B port of the second rotary balance valve is connected to the rotary motor.

[0021] The main boom luffing balance valve assembly includes a main boom luffing balance valve and a shut-off valve. The T port of the proportional directional valve in the main boom load linkage C is connected to the A port and C port of the main boom luffing balance valve, respectively. The B port of the main boom luffing balance valve is connected to the rodless chamber of the main boom luffing hydraulic cylinder via the main boom luffing explosion-proof valve. The rod chamber of the main boom luffing hydraulic cylinder is connected to the B port of the proportional directional valve in the main boom load linkage C. The oil circuit between the B port of the main boom luffing balance valve and the main boom luffing explosion-proof valve and the rod chamber of the main boom luffing hydraulic cylinder is equipped with a damping and shut-off valve.

[0022] The boom luffing balance valve assembly includes a first boom luffing balance valve and a second boom luffing balance valve. The T port of the proportional directional valve in the boom luffing linkage D is connected to the A port of the first boom luffing balance valve and the A port of the second boom luffing balance valve, respectively. The B port of the first boom luffing balance valve is connected to the rodless chamber of the boom luffing hydraulic cylinder via a first boom luffing explosion-proof valve. The B port of the second boom luffing balance valve is connected to the rod chamber of the boom luffing hydraulic cylinder via a second boom luffing explosion-proof valve. The A port of the first boom luffing balance valve is connected to the C port of the second boom luffing balance valve, and the C port of the first boom luffing balance valve is connected to the A port of the second boom luffing balance valve.

[0023] The electromagnetic on / off valve group includes a first electromagnetic ball valve, a second electromagnetic ball valve, a third electromagnetic ball valve, and a fourth electromagnetic ball valve. The two main pumps are connected to the first electromagnetic ball valve, the second electromagnetic ball valve, the third electromagnetic ball valve, and the fourth electromagnetic ball valve in sequence via port P. The first electromagnetic ball valve is connected to the P port of the horizontal servo valve group via port P. The second electromagnetic ball valve is connected to the P port of the swing servo valve group via port P. The third electromagnetic ball valve is connected to the P port of the first-stage vertical telescopic servo valve group via port P. The fourth electromagnetic ball valve is connected to the P port of the second-stage vertical telescopic servo valve group via port P.

[0024] The horizontal servo valve group includes a horizontal servo valve and a horizontal solenoid directional valve. A solenoid ball valve is connected to the P port of the horizontal servo valve via the P port. The A port of the horizontal servo valve is connected to the A port of a horizontal locking valve. The B port of the horizontal locking valve is connected to the rodless chamber of the horizontal telescopic hydraulic cylinder. The T port of the horizontal servo valve is connected to the oil tank via a cooler and a filter. The B port of the horizontal servo valve is connected to the A port of the second horizontal locking valve. The B port of the second horizontal locking valve is connected to the rod chamber of the horizontal telescopic hydraulic cylinder. A displacement sensor is installed on the horizontal telescopic hydraulic cylinder. The displacement sensor is connected to the horizontal servo valve via a signal connection.

[0025] The A port of the horizontal solenoid directional valve is connected to the control pump, the B port of the horizontal solenoid directional valve is connected to the oil tank, the T port of the horizontal solenoid directional valve is connected to the X port of a first horizontal lock valve and the X port of a second horizontal lock valve, and the B port of the horizontal solenoid directional valve is connected to the Y port of a first horizontal lock valve and the Y port of a second horizontal lock valve.

[0026] The first-stage vertical telescopic servo valve group includes a first-stage vertical servo valve and a first-stage vertical solenoid directional valve. The three solenoid ball valves are connected to the P port of the first-stage vertical servo valve via the P port. The A port of the first-stage vertical servo valve is connected to the rodless chamber of the first-stage vertical telescopic hydraulic cylinder. The T port of the first-stage vertical servo valve is connected to the oil tank via the cooler and filter. The B port of the first-stage vertical servo valve is connected to the A port of the first-stage vertical locking valve. The B port of the first-stage vertical locking valve is connected to the rod chamber of the first-stage vertical telescopic hydraulic cylinder. Two displacement sensors are installed on the first-stage vertical telescopic hydraulic cylinder, and the signals of the two displacement sensors are connected to the first-stage vertical servo valve.

[0027] The A port of the first-stage vertical solenoid directional valve is connected to the control pump, the B port of the first-stage vertical solenoid directional valve is connected to the oil tank, the T port of the first-stage vertical solenoid directional valve is connected to the X port of the first-stage vertical lock valve, and the B port of the first-stage vertical solenoid directional valve is connected to the Y port of the first-stage vertical lock valve.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. In a multi-degree-of-freedom active compensation crane hydraulic system of the present invention, port A of the horizontal servo valve group is connected to the rodless chamber of the horizontal telescopic hydraulic cylinder, port B of the horizontal servo valve group is connected to the rod chamber of the horizontal telescopic hydraulic cylinder, port A of the first-stage vertical telescopic servo valve group is connected to the rodless chamber of the first-stage vertical telescopic hydraulic cylinder, and port B of a horizontal locking valve is connected to the rodless chamber of the horizontal telescopic hydraulic cylinder. The horizontal servo cylinder is used to achieve active compensation in the Y direction. Compared with ordinary cylinders, its piston rod has a faster movement speed, lower friction, lower minimum stable movement speed, and lower minimum stable movement pressure. A displacement sensor is installed on the piston rod to detect the piston rod displacement in real time and transmit the displacement signal to the controller integrated with the horizontal servo valve for servo control in the Y direction, enabling rapid movement following the target. The swing servo valve group is used for active compensation in the X direction, and the first-stage and second-stage vertical telescopic servo valve groups are used for active compensation in the Z direction, realizing multi-degree-of-freedom motion grasping. Therefore, this design not only achieves multi-degree-of-freedom motion grasping but is also simple to operate.

[0030] 2. In the multi-degree-of-freedom active compensation crane hydraulic system of this invention, port B of the horizontal servo valve is connected to port A of the two horizontal locking valves. Port B of the two horizontal locking valves is connected to the rod chamber of the horizontal telescopic hydraulic cylinder. The piston rod of the horizontal telescopic hydraulic cylinder is connected to the horizontal servo valve. The horizontal servo valve, the horizontal locking valve, and the horizontal solenoid directional valve are all integrated and mounted on a single valve block, which is directly mounted on the rodless chamber port of the cylinder. This shortens the oil passage between the servo valve and the cylinder, reducing the volume and mass of the oil. This not only improves the dynamic characteristics of the system but also prevents pipe bursts, ensuring safety and reliability. Therefore, this design improves the dynamic characteristics of the system and ensures safety and reliability.

[0031] 3. In the multi-degree-of-freedom active compensation crane hydraulic system of this invention, the oil outlet of the first-stage vertical servo valve and the first-stage vertical solenoid directional valve, and the three solenoid ball valve are connected to the P port of the first-stage vertical servo valve via the P port. The A port of the first-stage vertical servo valve is connected to the rodless chamber of the first-stage vertical telescopic hydraulic cylinder. The combined telescopic movement of the first and second-stage vertical telescopic hydraulic cylinders not only significantly reduces the volume but also doubles the active compensation speed in the Z direction, eliminating the limitation of the fastest speed of a single hydraulic cylinder piston rod. Therefore, this design occupies little space and has a fast compensation speed. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention.

[0033] Figure 2 This is a schematic diagram of the main pump assembly in this invention.

[0034] Figure 3 This is a schematic diagram of the rotary coupling structure in this invention.

[0035] Figure 4 This is a schematic diagram of the rotary balance valve assembly in this invention.

[0036] Figure 5 This is a schematic diagram of the connection structure between the rotary coupling and the rotary balance valve group in this invention.

[0037] Figure 6 This is a schematic diagram of the horizontal servo valve assembly in this invention.

[0038] Figure 7 This is a schematic diagram of the electromagnetic on / off valve assembly in this invention.

[0039] In the diagram: 1. Oil tank; 2. Electric motor; 3. Main pump 1; 4. Main pump 2; 5. Control pump; 6. Relief valve; 7. Accumulator; 8. Multi-way valve; 12. Rotary motor; 13. Rotary brake; 39. Cooler; 40. Filter; 40. Main pump assembly A; 46. Rotary coupling B; 47. Shuttle valve 1; 48. Load-sensitive relief valve 2; 49. Proportional directional valve; 50. Make-up check valve 2; 51. Make-up check valve 3; 52. Shuttle valve 4. Shuttle valve 5. Load-sensitive relief valve 5. Main boom load coupling C, folding boom luffing coupling D, slewing balance valve assembly E, slewing shuttle valve 9, hydraulic directional valve 10, first slewing balance valve 11.1, second slewing balance valve 11.2, main boom luffing balance valve assembly F, main boom luffing balance valve 14, shut-off valve 15, damping valve 16, main boom luffing explosion-proof valve 17, main boom luffing hydraulic cylinder 18, folding boom luffing balance valve assembly G, first folding boom luffing balance valve 19.1, second folding boom luffing balance valve 19.2, Explosion-proof valve for boom luffing; 20.1, Explosion-proof valve for boom luffing; 20.2, Boom luffing hydraulic cylinder; 21, Electromagnetic on / off valve group H; 22.1, Electromagnetic ball valve; 22.2, Electromagnetic ball valve; 22.3, Electromagnetic ball valve; 22.4, Electromagnetic ball valve; 22.5, Horizontal servo valve group I; 23, Horizontal servo valve; 24, Horizontal solenoid directional valve; 25.1, Horizontal locking valve; 25.2, Horizontal telescopic hydraulic cylinder; 26, Displacement sensor; 53, Swing servo valve group J; Swing hydraulic cylinder; 30, First-stage vertical telescopic servo valve group K; First-stage vertical servo valve; 31, First-stage vertical solenoid directional valve; 32, First-stage vertical locking valve; 33, First-stage vertical telescopic hydraulic cylinder; 34, Second-stage displacement sensor; 54, Second-stage vertical telescopic servo valve group L; Oil inlet connector M; Main relief valve; 41, Sequence valve; 42, Control oil pressure reducing valve; 43, Control oil relief valve. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] See Figures 1 to 7 To achieve the above objectives, the technical solution of the present invention is: a multi-degree-of-freedom active compensation crane hydraulic system, the multi-degree-of-freedom active compensation crane hydraulic system including an oil tank 1, a main pump assembly A, a slewing coupling B, a slewing balance valve group E, a main boom luffing balance valve group F, a folding boom luffing balance valve group G, and an oil inlet coupling M.

[0042] The oil outlet of the oil tank 1 is connected to the oil inlet of the main pump assembly A. The motor 2 is connected to the main pump assembly A. The main pump assembly A includes a main pump 3, two main pumps 4 and a control pump 5. The oil outlet of the oil tank 1 is connected to the oil inlet of the main pump 3, the oil inlet of the two main pumps 4 and the oil inlet of the control pump 5 respectively. The oil outlet of the main pump 3 is connected to the oil inlet of the oil inlet coupling M, the oil inlet of the slewing coupling B, the oil inlet of the main boom load coupling C and the oil inlet of the folding boom luffing coupling D.

[0043] The A1 port of the rotary coupling B is connected to the E2 port of the rotary balance valve group E, the B1 port of the rotary coupling B is connected to the E3 port of the rotary balance valve group E, the E5 port of the rotary balance valve group E is connected to the rotary motor 12, the E4 port of the rotary balance valve group E is connected to the rotary motor 12, and the E1 port of the rotary balance valve group E is connected to the oil tank 1.

[0044] The A2 port of the main boom load coupling C is connected to the F1 port of the main boom luffing balance valve group F, the B2 port of the main boom load coupling C is connected to the F2 port of the main boom luffing balance valve group F, the F4 port of the main boom luffing balance valve group F is connected to the rodless chamber of the main boom luffing hydraulic cylinder 18, and the F3 port of the main boom luffing balance valve group F is connected to the rod chamber of the main boom luffing hydraulic cylinder 18.

[0045] The A3 port of the boom luffing coupling D is connected to the G1 port of the boom luffing balance valve group G, the B3 port of the boom luffing coupling D is connected to the G2 port of the boom luffing balance valve group G, the G4 port of the boom luffing balance valve group G is connected to the rodless chamber of the boom luffing hydraulic cylinder 21, and the G3 port of the boom luffing balance valve group G is connected to the rod chamber of the boom luffing hydraulic cylinder 21.

[0046] The T-ports of the oil inlet M, the slewing B, the main boom load C, and the boom luffing D are all connected to the oil tank 1.

[0047] The two main pumps 4 are connected to the P1 port of the electromagnetic on / off valve group H, the P2 port of the electromagnetic on / off valve group H is connected to the P1 port of the horizontal servo valve group I, the P3 port of the electromagnetic on / off valve group H is connected to the P1 port of the swing servo valve group J, the P4 port of the electromagnetic on / off valve group H is connected to the P1 port of the first-stage vertical telescopic servo valve group K, and the P5 port of the electromagnetic on / off valve group H is connected to the P1 port of the second-stage vertical telescopic servo valve group L.

[0048] The horizontal servo valve group I has the same structure as the swing servo valve group J, and the T1 port of the horizontal servo valve group I is connected to the oil tank 1.

[0049] The structure of the first-stage vertical telescopic servo valve group K is the same as that of the second-stage vertical telescopic servo valve group L. The T1 port of the first-stage vertical telescopic servo valve group K is connected to the oil tank 1.

[0050] The A1 port of the horizontal servo valve group I is connected to the rodless chamber of the horizontal telescopic hydraulic cylinder 26, the B1 port of the horizontal servo valve group I is connected to the rod chamber of the horizontal telescopic hydraulic cylinder 26, the A1 port of the first-stage vertical telescopic servo valve group K is connected to the rodless chamber of the first-stage vertical telescopic hydraulic cylinder 34, and the B1 port of the first-stage vertical telescopic servo valve group K is connected to the rod chamber of the first-stage vertical telescopic hydraulic cylinder 34.

[0051] The R1 port of the horizontal servo valve group I is connected to the control pump 5, the R1 port of the first-stage vertical telescopic servo valve group K is connected to the control pump 5, the L1 port of the horizontal servo valve group I is connected to the oil tank 1, and the L1 port of the first-stage vertical telescopic servo valve group K is connected to the oil tank 1.

[0052] The oil inlet coupling M includes a main relief valve 41, a sequence valve 42, a control oil pressure reducing valve 43, and a control oil relief valve 44. The main relief valve 41, the sequence valve 42, the control oil pressure reducing valve 43, and the control oil relief valve 44 are connected to each other, and the control oil relief valve 44 is connected to the rotary coupling B.

[0053] The slewing coupling B, main boom load coupling C, and boom luffing coupling D have the same structure. The slewing coupling B includes a shuttle valve 46, a proportional directional valve 48, and a second shuttle valve 51. The main pump 3 is connected to the P port of the proportional directional valve 48, the T1 port of the proportional directional valve 48 is connected to the oil tank 1, the B port of the proportional directional valve 48 is connected to the B port of the second shuttle valve 51, the A port of the proportional directional valve 48 is connected to the A port of the second shuttle valve 51, the C port of the second shuttle valve 51 is connected to the A port of the first shuttle valve 46, the C port of the first shuttle valve 46 is connected to the LS port of the main pump 3, the B port of the first shuttle valve 46 is connected to the main boom load coupling C, and the T1 port of the proportional directional valve 48 is connected to the E2 port and the E3 port of the slewing balance valve group E, respectively.

[0054] A load-sensitive relief valve 47 and a second load-sensitive relief valve 52 are provided between the oil circuits of the first shuttle valve 46 and the second shuttle valve 51. The A port of the first shuttle valve 46 is connected to the P port of the proportional directional valve 48 via the differential pressure compensator 45. A replenishing oil check valve 49 is provided between the A port and the T1 port of the proportional directional valve 48. A second replenishing oil check valve 50 is provided between the B port and the T1 port of the proportional directional valve 48.

[0055] The rotary balance valve group E includes a rotary shuttle valve 9 and a hydraulic directional valve 10. The T1 port of the proportional directional valve 48 is connected to the A port and B port of the rotary shuttle valve 9, respectively. The C port of the rotary shuttle valve 9 is connected to the oil inlet of the hydraulic directional valve 10. The oil outlet of the hydraulic directional valve 10 is connected to the rotary brake 13. The oil outlet of the hydraulic directional valve 10 is connected to the oil tank 1. The rotary brake 13 is mounted on the rotary motor 12. The A port of the rotary shuttle valve 9 is connected to the A port of a rotary balance valve 11.1. The B port of the rotary balance valve 11.1 is connected to the rotary motor 12. The B port of the rotary shuttle valve 9 is connected to the A port of a second rotary balance valve 11.2. The B port of the second rotary balance valve 11.2 is connected to the rotary motor 12.

[0056] The main boom luffing balance valve group F includes a main boom luffing balance valve 14 and a shut-off valve 15. The T1 port of the proportional directional valve 48 in the main boom load connection C is connected to the A port and the C port of the main boom luffing balance valve 14, respectively. The B port of the main boom luffing balance valve 14 is connected to the rodless chamber of the main boom luffing hydraulic cylinder 18 via the main boom luffing explosion-proof valve 17. The rod chamber of the main boom luffing hydraulic cylinder 18 is connected to the B port of the proportional directional valve 48 in the main boom load connection C. The oil circuit between the B port of the main boom luffing balance valve 14 and the main boom luffing explosion-proof valve 17 and the rod chamber of the main boom luffing hydraulic cylinder 18 is equipped with a damping valve 16 and a shut-off valve 15.

[0057] The boom luffing balance valve group G includes a boom luffing balance valve 19.1 and a boom luffing balance valve 19.2. The T1 port of the proportional directional valve 48 in the boom luffing coupling D is connected to the A port of the boom luffing balance valve 19.1 and the A port of the boom luffing balance valve 19.2, respectively. The B port of the boom luffing balance valve 19.1 is connected to the rodless chamber of the boom luffing hydraulic cylinder 21 via the boom luffing explosion-proof valve 20.1. The B port of the boom luffing balance valve 19.2 is connected to the rod chamber of the boom luffing hydraulic cylinder 21 via the boom luffing explosion-proof valve 20.2. The A port of the boom luffing balance valve 19.1 is connected to the C port of the boom luffing balance valve 19.2, and the C port of the boom luffing balance valve 19.1 is connected to the A port of the boom luffing balance valve 19.2.

[0058] The electromagnetic on / off valve group H includes a solenoid ball valve 22.1, a solenoid ball valve 22.2, a solenoid ball valve 22.3, and a solenoid ball valve 22.4. The two main pumps 4 are connected sequentially to the solenoid ball valves 22.1, 22.2, 22.3, and 22.4 via port P1. The solenoid ball valve 22.1 is connected to port P1 of the horizontal servo valve group I via port P2. The solenoid ball valve 22.2 is connected to port P1 of the swing servo valve group J via port P3. The solenoid ball valve 22.3 is connected to port P1 of the first-stage vertical telescopic servo valve group K via port P4. The solenoid ball valve 22.4 is connected to port P1 of the second-stage vertical telescopic servo valve group L via port P5.

[0059] The horizontal servo valve group I includes a horizontal servo valve 23 and a horizontal solenoid directional valve 24. A solenoid ball valve 22.1 is connected to the P port of the horizontal servo valve 23 via port P2. The A port of the horizontal servo valve 23 is connected to the A port of a horizontal locking valve 25.1. The B port of the horizontal locking valve 25.1 is connected to the rodless chamber of the horizontal telescopic hydraulic cylinder 26. The T port of the horizontal servo valve 23 is connected to the oil tank 1 via a cooler 39 and a filter 40. The B port of the horizontal servo valve 23 is connected to the A port of two horizontal locking valves 25.2. The B port of the two horizontal locking valves 25.2 is connected to the rod chamber of the horizontal telescopic hydraulic cylinder 26. A displacement sensor 53 is installed on the horizontal telescopic hydraulic cylinder 26. The displacement sensor 53 is signal-connected to the horizontal servo valve 23.

[0060] The A port of the horizontal solenoid directional valve 24 is connected to the control pump 5, the B port of the horizontal solenoid directional valve 24 is connected to the oil tank 1, the T port of the horizontal solenoid directional valve 24 is connected to the X port of a horizontal locking valve 25.1 and the X port of a horizontal locking valve 25.2 respectively, and the B port of the horizontal solenoid directional valve 24 is connected to the Y port of a horizontal locking valve 25.1 and the Y port of a horizontal locking valve 25.2 respectively.

[0061] The first-stage vertical telescopic servo valve group K includes a first-stage vertical servo valve 31 and a first-stage vertical solenoid directional valve 32. The three solenoid ball valves 22.3 are connected to the P port of the first-stage vertical servo valve 31 via the P4 port. The A port of the first-stage vertical servo valve 31 is connected to the rodless chamber of the first-stage vertical telescopic hydraulic cylinder 34. The T port of the first-stage vertical servo valve 31 is connected to the oil tank 1 via the cooler 39 and the filter 40. The B port of the first-stage vertical servo valve 31 is connected to the A port of the first-stage vertical locking valve 33. The B port of the first-stage vertical locking valve 33 is connected to the rod chamber of the first-stage vertical telescopic hydraulic cylinder 34. Two displacement sensors 54 are installed on the first-stage vertical telescopic hydraulic cylinder 34. The signals of the two displacement sensors 54 are connected to the first-stage vertical servo valve 31.

[0062] The A port of the first-stage vertical solenoid directional valve 32 is connected to the control pump 5, the B port of the first-stage vertical solenoid directional valve 32 is connected to the oil tank 1, the T port of the first-stage vertical solenoid directional valve 32 is connected to the X port of the first-stage vertical lock valve 33, and the B port of the first-stage vertical solenoid directional valve 32 is connected to the Y port of the first-stage vertical lock valve 33.

[0063] The principle of this invention is explained as follows:

[0064] When the proportional directional valve 48 in the rotary coupling B is in the neutral position, port P is blocked, and ports A and B are open to T. The pressure is basically zero, so the pressure at port C of shuttle valve 46 and shuttle valve 51 is also basically zero. At this time, the outlet pressure of the main pump 3 is 2 MPa, and the output flow of the main pump only maintains its own leakage and is in standby mode.

[0065] When the proportional directional valve 48 in the rotary coupling B is in the lower position, P is connected to A and B is connected to T. The pressure at port A is greater than the pressure at port B, so the outlet of the first shuttle valve 46 is the pressure at port A, which is transmitted to the spring chamber of the differential pressure compensator. The differential pressure compensator 45 keeps the pressure difference between P and port A at 2 MPa. The outlet of the first shuttle valve 46 enters the port A of the second shuttle valve 51. Since the proportional directional valves in other couplings are in the neutral position, the pressure at port B of the second shuttle valve 51 is basically zero. Therefore, the pressure at port C of the second shuttle valve 51 is the pressure at port A of the proportional directional valve, which is transmitted to the load-sensitive port of the first main pump 3. The outlet pressure of the first main pump 3 is always 2 MPa higher than the pressure at port A.

[0066] Since the pressure difference remains constant, the oil inlet flow of the proportional directional valve 48 in the rotary coupling B is only related to its opening. When the opening of the proportional directional valve 48 in the rotary coupling B increases, if the outlet flow of the main pump 3 remains constant, the pressure difference of the proportional directional valve 48 will be less than 2 MPa. The balance state of the load-sensitive relief valve 47 will be broken, causing the displacement and outlet flow of the main pump 3 to increase in order to maintain the pressure difference of 2 MPa. When the opening of the proportional directional valve 48 in the rotary coupling B decreases, the displacement and outlet flow of the main pump 3 will decrease.

[0067] The principle of multi-degree-of-freedom active compensation is as follows: When the horizontal telescopic hydraulic cylinder 26 is ready to start following the target's rapid movement, a solenoid ball valve 22.1 is energized, a main pump 3 is in high-pressure standby mode, and the outlet pressure oil of the main pump 3 reaches the P port of the horizontal servo valve 23. The horizontal solenoid directional valve 24 is energized, and the outlet pressure oil of the control pump enters the external control port X port of a horizontal lock valve 25.1 and a second horizontal lock valve 25.2 through this valve. The horizontal lock valve 25.1 is opened, and the horizontal servo valve 23 is still in the neutral position. Ports A and B are closed, and the horizontal telescopic hydraulic cylinder 26 supports the load under pressure. When the horizontal telescopic hydraulic cylinder 26 starts to follow the target's rapid movement, the outlet pressure oil of the main pump 3 enters the horizontal telescopic hydraulic cylinder 26 through the horizontal servo valve 23, driving the hydraulic cylinder to move rapidly to follow the target. The horizontal telescopic hydraulic cylinder 26 has an integrated displacement sensor 53, which is used to detect the actual position of the piston rod. This position signal is compared with the target position signal detected by the detection system, and its operation is controlled by the controller integrated on the horizontal servo valve 23, forming a closed-loop control.

[0068] In case of an emergency, the motor 2 and all solenoid valves are de-energized. A solenoid ball valve 22.1 automatically and quickly resets under the action of a spring, cutting off the oil circuit connecting the main pump 3 and the horizontal servo valve 23 to prevent pressurized oil from entering the horizontal telescopic hydraulic cylinder 26 and causing malfunction of the cylinder. The horizontal servo valve 23 also automatically and quickly returns to the leftmost safe position under the action of a spring. The two horizontal shuttle valves 25.2 automatically close to prevent pressurized oil from entering the horizontal telescopic hydraulic cylinder 26 and causing malfunction of the hydraulic cylinder.

[0069] Example 1:

[0070] A multi-degree-of-freedom active compensation crane hydraulic system includes an oil tank 1, a main pump assembly A, a slewing coupling B, a slewing balance valve assembly E, a main boom luffing balance valve assembly F, a folding boom luffing balance valve assembly G, and an oil inlet coupling M. The oil outlet of the oil tank 1 is connected to the oil inlet of the main pump assembly A. An electric motor 2 is connected to the main pump assembly A. The main pump assembly A includes a main pump 3, two main pumps 4, and a control pump 5. The oil outlet of the oil tank 1 is connected to the oil inlets of the main pump 3, the two main pumps 4, and the control pump 5, respectively. The oil outlet of the main pump 3 is connected to the oil inlets of the oil inlet coupling M, the slewing coupling B, the main boom load coupling C, and the folding boom luffing coupling D. The A1 port of the slewing coupling B... The slewing balance valve group E is connected to port E2; the slewing coupling B is connected to port E3; the slewing balance valve group E is connected to port E5; the slewing motor 12 is connected to port E4; and the oil tank 1 is connected to port E1. The main boom load coupling C is connected to port F1; the main boom load coupling C is connected to port F2; the main boom luffing balance valve group F is connected to port F4; the main boom luffing balance valve group F is connected to the rodless chamber of the main boom luffing hydraulic cylinder 18; and the main boom luffing balance valve group F is connected to the rod-side chamber of the main boom luffing hydraulic cylinder 18. The folding boom luffing coupling D is connected to port G1; and the folding boom luffing coupling D is connected to port G1. Port B3 of boom luffing balance valve group G is connected to port G2 of boom luffing balance valve group G; port G4 of boom luffing balance valve group G is connected to the rodless chamber of boom luffing hydraulic cylinder 21; port G3 of boom luffing balance valve group G is connected to the rod chamber of boom luffing hydraulic cylinder 21; ports T of oil inlet M, slewing B, main boom load C, and boom luffing D are all connected to oil tank 1; the second main pump 4 is connected to port P1 of electromagnetic on / off valve group H; port P2 of electromagnetic on / off valve group H is connected to port P1 of horizontal servo valve group I; port P3 of electromagnetic on / off valve group H is connected to port P1 of swing servo valve group J; port P4 of electromagnetic on / off valve group H is connected to port P1 of first-stage vertical telescopic servo valve group K; port P5 of electromagnetic on / off valve group H is connected to... The P1 port of the secondary vertical telescopic servo valve group L is connected; the horizontal servo valve group I has the same structure as the swing servo valve group J, and the T1 port of the horizontal servo valve group I is connected to the oil tank 1; the primary vertical telescopic servo valve group K has the same structure as the secondary vertical telescopic servo valve group L, and the T1 port of the primary vertical telescopic servo valve group K is connected to the oil tank 1; the A1 port of the horizontal servo valve group I is connected to the rodless chamber of the horizontal telescopic hydraulic cylinder 26, the B1 port of the horizontal servo valve group I is connected to the rod chamber of the horizontal telescopic hydraulic cylinder 26, the A1 port of the primary vertical telescopic servo valve group K is connected to the rodless chamber of the primary vertical telescopic hydraulic cylinder 34, and the B1 port of the primary vertical telescopic servo valve group K is connected to the rod chamber of the primary vertical telescopic hydraulic cylinder 34.The R1 port of the horizontal servo valve group I is connected to the control pump 5, and the R1 port of the first-stage vertical telescopic servo valve group K is connected to the control pump 5. The L1 port of the horizontal servo valve group I is connected to the oil tank 1, and the L1 port of the first-stage vertical telescopic servo valve group K is connected to the oil tank 1.

[0071] In application: When the proportional directional valve 48 in rotary coupling B is in the neutral position, port P is blocked, and ports A and B are open to T. The pressure is basically zero, and the main pump output flow only maintains its own leakage, remaining in standby mode. When the proportional directional valve 48 in rotary coupling B is in the lower position, P is open to A, and B is open to T. The pressure at port A is greater than the pressure at port B. Since the proportional directional valves in other couplings are in the neutral position, the pressure in rotary coupling B is basically zero, and the outlet pressure of the first main pump 3 is always 2 MPa higher than the pressure at port A. Since the pressure difference remains constant, the oil inlet flow of the proportional directional valve 48 in rotary coupling B is only related to its opening. When the opening of the proportional directional valve 48 in rotary coupling B increases, if the outlet flow of the first main pump 3 remains unchanged, the pressure difference will be less than 2 MPa, breaking the balance and increasing the displacement and outlet flow of the first main pump 3 to maintain the pressure difference at 2 MPa. When the opening of rotary coupling B decreases, the displacement and outlet flow of the first main pump 3 decrease.

[0072] Example 2:

[0073] Example 2 is basically the same as Example 1, except that:

[0074] A multi-degree-of-freedom active compensation crane hydraulic system includes an inlet coupling M comprising a main relief valve 41, a sequence valve 42, a control oil pressure reducing valve 43, and a control oil relief valve 44. The outlet of a main pump 3 is connected to the inlet of the main relief valve 41, sequence valve 42, control oil pressure reducing valve 43, and control oil relief valve 44. The outlets of the main relief valve 41, sequence valve 42, control oil pressure reducing valve 43, and control oil relief valve 44 are connected to an oil tank 1. The oil passages between the T-port of the inlet coupling M and the oil tank 1, the oil passage between the T-port of the slewing coupling B and the oil tank 1, the oil passage between the T-port of the main boom load coupling C and the oil tank 1, and the oil passage between the T-port of the folding boom luffing coupling D and the oil tank 1 are all sequentially equipped with a cooler 39 and a filter 40. The main relief valve 41 is used to limit the maximum working pressure at the inlet, and the sequence valve 42 is used to limit the pressure difference between the inlet and the load-sensitive port; when the difference exceeds the valve's spring setting value of 3 MPa... Afterwards, the pressure relief valve 43 is opened to reduce the pressure of the high-pressure oil at the inlet, providing control oil to each control circuit. The control oil overflow valve 44 is used to limit the maximum working pressure of the control oil circuit.

[0075] Example 3:

[0076] Example 3 is basically the same as Example 2, except that:

[0077] A multi-degree-of-freedom active compensation hydraulic system for a crane, wherein the slewing coupling B, the main boom load coupling C, and the folding boom luffing coupling D have the same structure. The slewing coupling B includes a shuttle valve 46, a proportional directional valve 48, and a second shuttle valve 51. A main pump 3 is connected to the P port of the proportional directional valve 48, the T1 port of the proportional directional valve 48 is connected to the oil tank 1, the B port of the proportional directional valve 48 is connected to the B port of the second shuttle valve 51, and the A port of the proportional directional valve 48 is connected to the A port of the second shuttle valve 51. The proportional directional valve 48 performs reversing and speed adjustment according to the control voltage. The control voltage of the proportional directional valve 48 is -10V to 10V, with a neutral voltage of 0V. In the neutral position, the P ports of all coupling valve cores are blocked, and the A ports are... Port B is connected to T. Taking the rotary coupling B as an example, when the control voltage is 0~10V, the rotary coupling B valve core works in the lower position, corresponding to P→A, B→T, and the rotation is right. When the control voltage is 0~-10V, the rotary coupling B valve core works in the upper position, corresponding to P→B, A→T, and the rotation is left. The larger the absolute value of the control voltage, the larger the valve core opening, the larger the flow rate, and the faster the speed. Port C of the second shuttle valve 51 is connected to port A of the first shuttle valve 46. Port C of the first shuttle valve 46 is connected to port LS of the first main pump 3. Port B of the first shuttle valve 46 is connected to port C of the main arm load coupling. Port T1 of the proportional directional valve 48 is connected to port E2 and port E3 of the rotary balance valve group E, respectively.

[0078] A load-sensitive relief valve 47 and a load-sensitive relief valve 52 are installed between the oil circuits of the first shuttle valve 46 and the second shuttle valve 51. The first shuttle valve 46 and the second shuttle valve 51 are used to supply pressurized oil to the rotary brake 13. A replenishing check valve 49 is installed on the oil circuit between port A and port T1 of the proportional directional valve 48. The differential pressure compensator 45 is used to stabilize the pressure difference between port P and port A or B in the proportional directional valve 48. A replenishing check valve 50 is installed on the oil circuit between port B and T1 of the proportional directional valve 48. The first load-sensitive relief valve 47 and the second load-sensitive relief valve 52 are used to limit the maximum pressure at ports A and B. The first replenishing check valve 49 and the second replenishing check valve 50 are used to replenish oil to ports A and B from the return port in the reverse direction to prevent cavitation. The first shuttle valve 46 is used to transmit the higher working pressure at ports A and B to the spring chamber of the differential pressure compensator 45, so that the pressure difference between port P and port A or B of the proportional directional valve 48 is maintained at 2 MPa. The flow rate remains unchanged because the inlet flow rate of the proportional directional valve 48 is related to its inlet pressure differential and valve core opening. When the pressure differential remains unchanged, the flow rate is only related to the valve core opening, that is, only related to the control voltage, thereby achieving proportional speed regulation. When two or three control lines operate in conjunction, the shuttle valve 51 is used to transmit the highest working pressure of all control lines to the load sensitive port of the main pump 3, so that the outlet pressure of the main pump 3 is always 2 MPa higher than the highest working pressure. The valve port of the differential pressure compensator 45 of other control lines with load pressures other than the highest is closed, so that the inlet pressure differential of the proportional directional valve 48 is also maintained at 2 MPa.

[0079] Example 4:

[0080] Example 4 is basically the same as Example 3, except that:

[0081] A multi-degree-of-freedom active compensation hydraulic system for a crane includes a slewing balance valve group E comprising a slewing shuttle valve 9 and a hydraulically controlled directional valve 10. The T1 port of the proportional directional valve 48 is connected to ports A and B of the slewing shuttle valve 9, respectively. The C port of the slewing shuttle valve 9 is connected to the inlet of the hydraulically controlled directional valve 10. The outlet of the hydraulically controlled directional valve 10 is connected to a slewing brake 13 and an oil tank 1. The slewing brake 13 is mounted on a slewing motor 12. Port A of the slewing shuttle valve 9 is connected to port A of a slewing balance valve 11.1, and port B of the slewing balance valve 11.1 is connected to the slewing motor 12. Motor 12 is connected, and port B of rotary shuttle valve 9 is connected to port A of second rotary balance valve 11.2. Port B of second rotary balance valve 11.2 is connected to rotary motor 12. First rotary balance valve 11.1 and second rotary balance valve 11.2 are used to balance the rotary load. When rotating to the right, first rotary balance valve 11.1 works in the left position, and oil flows from port A to port B, which is equivalent to a check valve. Second rotary balance valve 11.2 works in the right position under the pressure of port A, and oil flows from port B to port A. The opening size of the balance valve is adjusted according to the load size and the pressure of port A. The working principle is the same when rotating to the left.

[0082] Example 5:

[0083] Example 5 is basically the same as Example 1, except that:

[0084] A multi-degree-of-freedom active compensation crane hydraulic system includes a main boom luffing balance valve group F comprising a main boom luffing balance valve 14 and a shut-off valve 15. The T1 port of the proportional directional valve 48 in the main boom load linkage C is connected to ports A and C of the main boom luffing balance valve 14. Port B of the main boom luffing balance valve 14 is connected to the rodless chamber of the main boom luffing hydraulic cylinder 18 via a main boom luffing explosion-proof valve 17. The rod chamber of the main boom luffing hydraulic cylinder 18 is connected to port B of the proportional directional valve 48 in the main boom load linkage C. A damping valve 16 and a shut-off valve 15 are installed in the oil circuit between port B of the main boom luffing balance valve 14, the main boom luffing explosion-proof valve 17, and the rod chamber of the main boom luffing hydraulic cylinder 18. The shut-off valve 15 and damping valve 16 are used to depressurize the rodless chamber of the main boom luffing hydraulic cylinder 18 when the system loses power, causing the piston rod to retract manually. The main boom luffing balance valve 14 is used to balance the load of the main boom luffing hydraulic cylinder. Hydraulic cylinder 18 is only subjected to pressure, so a balance valve only needs to be installed in the rodless chamber. When lifting the load, the main boom luffing balance valve 15 operates in the left position, and the oil flows from port A to port B, which is equivalent to a check valve. When lowering the load, the main boom luffing balance valve 15 operates in the right position under the pressure of port B of the luffing proportional directional valve, and the oil flows from port B to port A. The opening size of the balance valve is adjusted according to the load size and the pressure at port B. Since the main boom luffing balance valve assembly F is relatively large, while the main boom luffing hydraulic cylinder 18 is relatively small, the main boom luffing balance valve assembly F cannot be installed in the oil port of the main boom luffing hydraulic cylinder 18. The two can only be connected by a steel pipe. To prevent the steel pipe from bursting, a main boom luffing explosion-proof valve 17 is installed in the oil port of the rodless chamber of the main boom luffing hydraulic cylinder 18. If the pipe bursts, the pressure difference corresponding to the flow rate through the explosion-proof valve exceeds the spring setting value, and the explosion-proof valve automatically switches to the left position, locking the main boom luffing hydraulic cylinder 18 to prevent stalling.

[0085] Example 6:

[0086] Example 6 is basically the same as Example 1, except that:

[0087] A multi-degree-of-freedom active compensation hydraulic system for a crane includes a boom luffing balance valve group G comprising a boom luffing balance valve 19.1 and a second boom luffing balance valve 19.2. The T1 port of the proportional directional valve 48 in the boom luffing linkage D is connected to the A ports of both the first and second boom luffing balance valves 19.1 and 19.2, respectively. The B port of the first boom luffing balance valve 19.1 is connected to the rodless chamber of the boom luffing hydraulic cylinder 21 via a boom luffing explosion-proof valve 20.1. The B port of the double-arm luffing balance valve 19.2 is connected to the rod chamber of the double-arm luffing hydraulic cylinder 21 via the double-arm luffing explosion-proof valve 20.2. The A port of the first-arm luffing balance valve 19.1 is connected to the C port of the double-arm luffing balance valve 19.2, and the C port of the first-arm luffing balance valve 19.1 is connected to the A port of the double-arm luffing balance valve 19.2. The first-arm luffing balance valve 19.1 and the double-arm luffing balance valve 19.2 are used to balance the load of the double-arm luffing hydraulic cylinder 21. Due to the luffing arm... Hydraulic cylinder 21 may be subjected to thrust or pressure, therefore balance valves need to be installed in both the rodless and rod chambers. When lifting the load, the first boom luffing balance valve 19.1 operates in the left position, with oil flowing from port A to port B, equivalent to a check valve; the second boom luffing balance valve 19.2 operates in the right position under the pressure at port A, with oil flowing from port B to port A, and the valve opening size is adjusted according to the load size and the pressure at port A. The working principle is the same when lowering the load. Due to the larger size of the boom luffing balance valve assembly G, the operation is different. Since the boom luffing hydraulic cylinder 21 is relatively small, the boom luffing balance valve group G cannot be installed at the oil port of the boom luffing hydraulic cylinder 21. The two can only be connected by a steel pipe. To prevent the steel pipe from bursting, a boom luffing explosion-proof valve 20.1 and a boom luffing explosion-proof valve 20.2 are installed at the rodless chamber oil port of the boom luffing hydraulic cylinder 21. If the pipe bursts, the pressure difference corresponding to the flow through the explosion-proof valve exceeds the spring setting value, and the explosion-proof valve automatically switches to the left position, locking the boom luffing hydraulic cylinder 21 to prevent stalling.

[0088] Example 7:

[0089] Example 7 is basically the same as Example 1, except that:

[0090] A multi-degree-of-freedom active compensation crane hydraulic system includes an electromagnetic on / off valve group H comprising a solenoid ball valve 22.1, a second solenoid ball valve 22.2, a third solenoid ball valve 22.3, and a fourth solenoid ball valve 22.4. The outlet of the two main pumps 4 is connected via an accumulator 7 through port P1 to the inlet of the first solenoid ball valve 22.1, the second solenoid ball valve 22.2, the third solenoid ball valve 22.3, and the fourth solenoid ball valve 22.4. The accumulator 7 stores the pressure oil from the two main pumps 4 and acts as an auxiliary oil source when the instantaneous system flow demand exceeds the flow rate of the two main pumps 4. The outlet of the first solenoid ball valve 22.1 is connected via port P2 to port P1 of the horizontal servo valve group I, and the outlet of the second solenoid ball valve 22.2 is connected via port P3 to port P1 of the swing servo valve group J. The third solenoid ball valve 22.1... The oil outlet of .3 is connected to the P1 port of the first-stage vertical telescopic servo valve group K via port P4. The oil outlet of the four solenoid ball valves 22.4 is connected to the P1 port of the second-stage vertical telescopic servo valve group L via port P5. The solenoid on / off valve group H is used to control whether the two main pumps 4 supply oil to each servo valve. When the servo valve is in the neutral position and the two main pumps 4 supply it with pressure oil, due to a certain leakage in the neutral position of the servo valve, the oil will return to the oil tank 1 from port P through the throttling effect of port T. In order to reduce the system heat generation, the solenoid on / off valve group H is opened only before the servo valve starts to work to supply oil to the servo valve. In addition, when the system suddenly loses power, the solenoid ball valve automatically and quickly resets under the action of the spring, cutting off the connection oil circuit between the two main pumps 4 and the servo valve, preventing the pressure oil from entering the servo cylinder and causing the cylinder to malfunction.

[0091] Example 8:

[0092] Example 8 is basically the same as Example 1, except that:

[0093] A multi-degree-of-freedom active compensation crane hydraulic system includes a horizontal servo valve group I comprising a horizontal servo valve 23 and a horizontal solenoid directional valve 24. A solenoid ball valve 22.1 is connected to the P port of the horizontal servo valve 23 via port P2. Port A of the horizontal servo valve 23 is connected to port A of a horizontal locking valve 25.1. Port B of the horizontal locking valve 25.1 is connected to the rodless chamber of a horizontal telescopic hydraulic cylinder 26. Port T of the horizontal servo valve 23 is connected to an oil tank 1 via a cooler 39 and a filter 40. Port B of the horizontal servo valve 23 is connected to port A of two horizontal locking valves 25.2. Port B of the two horizontal locking valves 25.2 is connected to the rod chamber of the horizontal telescopic hydraulic cylinder 26. A displacement sensor 53 is installed on the horizontal telescopic hydraulic cylinder 26 and is signal-connected to the horizontal servo valve 23. Port A of the horizontal solenoid directional valve 24 is connected to a control pump 5, and port B of the horizontal solenoid directional valve 24 is connected to the oil tank 1. The T port of the horizontal solenoid directional valve 24 is connected to the X port of a horizontal locking valve 25.1 and the X port of a horizontal locking valve 25.2, respectively. The B port of the horizontal solenoid directional valve 24 is connected to the Y port of a horizontal locking valve 25.1 and the Y port of a horizontal locking valve 25.2, respectively. An overflow valve 6, a cooler 39, and a filter are provided between the T1 port of the horizontal servo valve group I and the oil circuit of the oil tank 1, and between the T1 port of the first-stage vertical telescopic servo valve group K and the oil circuit of the oil tank 1. Device 40, when the control voltage is 0~10V, operates in the right position, with the valve core function being P→A, B→T, corresponding to the extension of the hydraulic cylinder piston rod; when the control voltage is 0~-10V, it operates in the left position, with the valve core function being P→B, A→T, corresponding to the retraction of the hydraulic cylinder piston rod. A horizontal locking valve 25.1 is an externally controlled, externally vented type, with port X being the external control port and port Y being the external venting port, and a control ratio of 3:1, meaning that when the pressure in the rodless chamber of the horizontal servo cylinder 26 is 30MPa... When the horizontal servo valve 23 is not working, the horizontal solenoid directional valve 24 on the control oil circuit is de-energized, and the first horizontal locking valve 25.1 is closed to lock the horizontal telescopic hydraulic cylinder 26. When the horizontal servo valve 23 is working, the horizontal solenoid directional valve 24 on the control oil circuit is energized, and the control oil enters the external control port of the second horizontal locking valve 25.2 to open it, so that the oil in the rodless chamber and the rod chamber of the horizontal telescopic hydraulic cylinder 26 can flow out freely.

[0094] When the horizontal solenoid directional valve 24 is de-energized, it operates in the right position, and the first horizontal locking valve 25.1 closes, locking the horizontal telescopic hydraulic cylinder 26. When the horizontal solenoid directional valve 24 is de-energized, it operates in the left position, and control oil enters the X port of the second horizontal locking valve 25.2. The second horizontal locking valve 25.2 X opens, and the piston rod of the horizontal telescopic hydraulic cylinder 26 is controlled to extend and retract through the horizontal servo valve 23.

[0095] The horizontal telescopic hydraulic cylinder 26 is used to achieve active compensation in the Y direction. Compared with ordinary hydraulic cylinders, its piston rod moves faster, has less friction, lower minimum stable movement speed, and lower minimum stable movement pressure. A displacement sensor 53 is installed on the piston rod to detect the piston rod displacement in real time and transmit the displacement signal to the controller integrated in the horizontal servo valve 23 to achieve servo control in the Y direction and follow the target to move quickly.

[0096] Example 9:

[0097] Example 9 is basically the same as Example 1, except that:

[0098] A multi-degree-of-freedom active compensation crane hydraulic system includes a first-stage vertical telescopic servo valve group K comprising a first-stage vertical servo valve 31 and a first-stage vertical solenoid directional valve 32. A three-electromagnetic ball valve 22.3 is connected to the P port of the first-stage vertical servo valve 31 via port P4. The A port of the first-stage vertical servo valve 31 is connected to the rodless chamber of the first-stage vertical telescopic hydraulic cylinder 34. The T port of the first-stage vertical servo valve 31 is connected to the oil tank 1 via a cooler 39 and a filter 40. The B port of the first-stage vertical servo valve 31 is connected to the A port of the first-stage vertical locking valve 33. The B port of the first-stage vertical locking valve 33 is connected to the rod chamber of the first-stage vertical telescopic hydraulic cylinder 34. Two displacement sensors 54 are installed on the first-stage vertical telescopic hydraulic cylinder 34, and the signals from the two displacement sensors 54 are connected to the first-stage vertical servo valve 31. The A port of the first-stage vertical solenoid directional valve 32 is connected to a control pump 5. An overflow valve 6 is installed on the oil line between port A of the direct solenoid directional valve 32 and the control pump 5. Port B of the first-stage vertical solenoid directional valve 32 is connected to the oil tank 1. Port T of the first-stage vertical solenoid directional valve 32 is connected to port X of the first-stage vertical locking valve 33. Port B of the first-stage vertical solenoid directional valve 32 is connected to port Y of the first-stage vertical locking valve 33. The first-stage vertical servo valve 31, the first-stage vertical solenoid directional valve 32, the first-stage vertical locking valve 33, and the first-stage vertical telescopic hydraulic cylinder 34 are used to realize active compensation in the Z direction. Since the load of the first-stage vertical telescopic hydraulic cylinder 34 is always downward and the rod chamber is always a high-pressure chamber, a locking valve is only installed in the rod chamber. The combined telescopic movement of the first-stage vertical telescopic hydraulic cylinder 34 and the second-stage vertical telescopic hydraulic cylinder 38 can not only significantly reduce the volume, but also double the active compensation speed in the Z direction, and is not limited by the fastest speed of the piston rod of a single hydraulic cylinder.

[0099] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A multi-degree of freedom actively compensated crane hydraulic system, characterized by The multi-degree-of-freedom active compensation crane hydraulic system comprises an oil tank (1), a main pump assembly (A), a rotating joint (B), a rotating balance valve group (E), a main arm luffing balance valve group (F), a folding arm luffing balance valve group (G) and an oil inlet joint (M); The oil outlet end of the oil tank (1) is communicated with the oil inlet end of the main pump assembly (A), the motor (2) is connected with the main pump assembly (A), the main pump assembly (A) comprises a main pump (3), a second main pump (4) and a control pump (5), the oil outlet end of the oil tank (1) is respectively communicated with the oil inlet end of the main pump (3), the oil inlet end of the second main pump (4) and the oil inlet end of the control pump (5), and the oil outlet end of the main pump (3) is sequentially communicated with the oil inlet end of the oil inlet joint (M), the oil inlet end of the rotating joint (B), the oil inlet end of the main arm load joint (C) and the oil inlet end of the folding arm luffing joint (D). The A1 port of the rotating joint (B) is communicated with the E2 port of the rotating balance valve group (E), the B1 port of the rotating joint (B) is communicated with the E3 port of the rotating balance valve group (E), the E5 port of the rotating balance valve group (E) is communicated with the rotating motor (12), the E4 port of the rotating balance valve group (E) is communicated with the rotating motor (12), and the E1 port of the rotating balance valve group (E) is communicated with the oil tank (1). The A2 port of the main arm load joint (C) is communicated with the F1 port of the main arm luffing balance valve group (F), the B2 port of the main arm load joint (C) is communicated with the F2 port of the main arm luffing balance valve group (F), the F4 port of the main arm luffing balance valve group (F) is communicated with the rodless cavity of the main arm luffing hydraulic cylinder (18), and the F3 port of the main arm luffing balance valve group (F) is communicated with the rod cavity of the main arm luffing hydraulic cylinder (18). The A3 port of the folding arm luffing joint (D) is communicated with the G1 port of the folding arm luffing balance valve group (G), the B3 port of the folding arm luffing joint (D) is communicated with the G2 port of the folding arm luffing balance valve group (G), the G4 port of the folding arm luffing balance valve group (G) is communicated with the rodless cavity of the folding arm luffing hydraulic cylinder (21), and the G3 port of the folding arm luffing balance valve group (G) is communicated with the rod cavity of the folding arm luffing hydraulic cylinder (21). The T port of the oil inlet joint (M) is communicated with the oil tank (1), the T port of the rotating joint (B) is communicated with the oil tank (1), the T port of the main arm load joint (C) is communicated with the oil tank (1), the T port of the folding arm luffing joint (D) is communicated with the oil tank (1), and the oil paths between the T port of the oil inlet joint (M) and the oil tank (1), the T port of the rotating joint (B) and the oil tank (1), the T port of the main arm load joint (C) and the oil tank (1), and the T port of the folding arm luffing joint (D) and the oil tank (1) are all provided with coolers (39) and filters (40). The second main pump (4) is communicated with the P1 port of the electromagnetic on-off valve group (H), the P2 port of the electromagnetic on-off valve group (H) is communicated with the P1 port of the horizontal servo valve group (I), the P3 port of the electromagnetic on-off valve group (H) is communicated with the P1 port of the swing servo valve group (J), the P4 port of the electromagnetic on-off valve group (H) is communicated with the P1 port of the first-stage vertical telescopic servo valve group (K), and the P5 port of the electromagnetic on-off valve group (H) is communicated with the P1 port of the second-stage vertical telescopic servo valve group (L). The horizontal servo valve group (I) and the swing servo valve group (J) are the same structure, the T1 port of the horizontal servo valve group (I) is communicated with the oil tank (1); The first level vertical telescopic servo valve group (K) and the second level vertical telescopic servo valve group (L) are the same structure, the T1 port of the first level vertical telescopic servo valve group (K) is communicated with the oil tank (1); The T1 port of the horizontal servo valve group (I) and the oil tank (1) are provided with a cooler (39) and a filter (40) between the oil circuit; The A1 port of the horizontal servo valve group (I) is communicated with the rodless cavity of the horizontal telescopic hydraulic cylinder (26), the B1 port of the horizontal servo valve group (I) is communicated with the rod cavity of the horizontal telescopic hydraulic cylinder (26), the A1 port of the first level vertical telescopic servo valve group (K) is communicated with the rodless cavity of the first level vertical telescopic hydraulic cylinder (34), the B1 port of the first level vertical telescopic servo valve group (K) is communicated with the rod cavity of the first level vertical telescopic hydraulic cylinder (34); The R1 port of the horizontal servo valve group (I) is communicated with the control pump (5), the R1 port of the first level vertical telescopic servo valve group (K) is communicated with the control pump (5), the L1 port of the horizontal servo valve group (I) is communicated with the oil tank (1), and the L1 port of the first level vertical telescopic servo valve group (K) is communicated with the oil tank (1).

2. A multi-degree of freedom active compensation crane hydraulic system according to claim 1, characterized in that: The oil inlet association (M) includes a main overflow valve (41), a sequence valve (42), a control oil pressure reducing valve (43), and a control oil overflow valve (44), which are communicated between them, and the control oil overflow valve (44) is communicated with the rotary association (B).

3. A multi-degree of freedom active compensation crane hydraulic system according to claim 2, characterized in that: The rotary association (B), the main arm load association (C), and the folding arm amplitude association (D) are the same structure, the rotary association (B) includes a shuttle valve (46), a proportional directional valve (48), and a two shuttle valve (51), the P port of the main pump (3) is communicated with the proportional directional valve (48), the T1 port of the proportional directional valve (48) is communicated with the oil tank (1), the B port of the proportional directional valve (48) is communicated with the B port of the two shuttle valve (51), the A port of the proportional directional valve (48) is communicated with the A port of the two shuttle valve (51), the C port of the two shuttle valve (51) is communicated with the A port of the one shuttle valve (46), the C port of the one shuttle valve (46) is communicated with the LS port of the main pump (3), the B port of the one shuttle valve (46) is communicated with the main arm load association (C), and the T1 port of the proportional directional valve (48) is respectively communicated with the E2 port of the rotary balance valve group (E) and the E3 port of the rotary balance valve group (E).

4. A multi-degree of freedom active compensation crane hydraulic system according to claim 3, characterized in that: A load sensitive overflow valve (47) and a two load sensitive overflow valve (52) are arranged between the oil circuit of the one shuttle valve (46) and the two shuttle valve (51), the A port of the one shuttle valve (46) is communicated with the P port of the proportional directional valve (48) through a differential pressure compensator (45), a supplementary oil check valve (49) is arranged on the oil circuit between the A port and the T1 port of the proportional directional valve (48), and a two supplementary oil check valve (50) is arranged on the oil circuit between the B port and T1 of the proportional directional valve (48).

5. A multi-degree of freedom active compensation crane hydraulic system according to claim 4, characterized in that: The rotary balance valve group (E) includes rotary shuttle valve (9) and hydraulic control reversing valve (10), T1 port of proportional directional valve (48) is communicated with A port and B port of rotary shuttle valve (9) respectively, C port of rotary shuttle valve (9) is communicated with oil inlet end of hydraulic control reversing valve (10), oil outlet end of hydraulic control reversing valve (10) is communicated with rotary brake (13), oil outlet end of hydraulic control reversing valve (10) is communicated with oil tank (1), rotary brake (13) is arranged on rotary motor (12), A port of rotary shuttle valve (9) is communicated with A port of rotary balance valve (11.1), B port of rotary balance valve (11.1) is communicated with rotary motor (12), B port of rotary shuttle valve (9) is communicated with A port of rotary balance valve (11.2), B port of rotary balance valve (11.2) is communicated with rotary motor (12).

6. A multi-degree of freedom active compensation crane hydraulic system according to claim 3, characterized in that: The main arm amplitude balance valve group (F) includes main arm amplitude balance valve (14) and stop valve (15), T1 port of proportional directional valve (48) in main arm load union (C) is communicated with A port and C port of main arm amplitude balance valve (14) respectively, B port of main arm amplitude balance valve (14) is communicated with rodless cavity of main arm amplitude hydraulic cylinder (18) through main arm amplitude explosion-proof valve (17), rod cavity of main arm amplitude hydraulic cylinder (18) is communicated with B port of proportional directional valve (48) in main arm load union (C), B port of main arm amplitude balance valve (14) is provided with damper (16) and stop valve (15) between oil circuit of main arm amplitude explosion-proof valve (17) and rod cavity of main arm amplitude hydraulic cylinder (18).

7. A multi-degree of freedom active compensation crane hydraulic system according to claim 3, characterized in that: The folding arm amplitude balance valve group (G) includes a folding arm amplitude balance valve (19.1) and a folding arm amplitude balance valve (19.2), T1 port of proportional directional valve (48) in folding arm amplitude union (D) is communicated with A port of a folding arm amplitude balance valve (19.1) and A port of a folding arm amplitude balance valve (19.2) respectively, B port of a folding arm amplitude balance valve (19.1) is communicated with rodless cavity of folding arm amplitude hydraulic cylinder (21) through a folding arm amplitude explosion-proof valve (20.1), B port of a folding arm amplitude balance valve (19.2) is communicated with rod cavity of folding arm amplitude hydraulic cylinder (21) through a folding arm amplitude explosion-proof valve (20.2), A port of a folding arm amplitude balance valve (19.1) is communicated with C port of a folding arm amplitude balance valve (19.2), C port of a folding arm amplitude balance valve (19.1) is communicated with A port of a folding arm amplitude balance valve (19.2).

8. A multi-degree of freedom active compensation crane hydraulic system according to claim 1, characterized in that: The electromagnetic on-off valve group (H) includes an electromagnetic ball valve (22.1), two electromagnetic ball valves (22.2), three electromagnetic ball valves (22.3) and four electromagnetic ball valves (22.4), the two main pumps (4) are communicated with the electromagnetic ball valve (22.1), the electromagnetic ball valve (22.2), the electromagnetic ball valve (22.3) and the electromagnetic ball valve (22.4) in sequence through the P1 port, the electromagnetic ball valve (22.1) is communicated with the P1 port of the horizontal servo valve group (I) through the P2 port, the electromagnetic ball valve (22.2) is communicated with the P1 port of the swing servo valve group (J) through the P3 port, the electromagnetic ball valve (22.3) is communicated with the P1 port of the first-stage vertical telescopic servo valve group (K) through the P4 port, and the electromagnetic ball valve (22.4) is communicated with the P1 port of the second-stage vertical telescopic servo valve group (L) through the P5 port.

9. The multi-degree-of-freedom active compensation crane hydraulic system according to claim 8, characterized in that: The horizontal servo valve group (I) includes a horizontal servo valve (23) and a horizontal electromagnetic reversing valve (24), the electromagnetic ball valve (22.1) is communicated with the P port of the horizontal servo valve (23) through the P2 port, the A port of the horizontal servo valve (23) is communicated with the A port of a horizontal lock valve (25.1), the B port of the horizontal lock valve (25.1) is communicated with the rodless cavity of the horizontal telescopic hydraulic cylinder (26), the T port of the horizontal servo valve (23) is communicated with the cooler (39), the filter (40) and the oil tank (1), the B port of the horizontal servo valve (23) is communicated with the A port of a second horizontal lock valve (25.2), the B port of the second horizontal lock valve (25.2) is communicated with the rod cavity of the horizontal telescopic hydraulic cylinder (26), a displacement sensor (53) is arranged on the horizontal telescopic hydraulic cylinder (26), and the displacement sensor (53) is signal connected with the horizontal servo valve (23); The A port of the horizontal electromagnetic reversing valve (24) is communicated with the control pump (5), the B port of the horizontal electromagnetic reversing valve (24) is communicated with the oil tank (1), the T port of the horizontal electromagnetic reversing valve (24) is respectively communicated with the X port of the horizontal lock valve (25.1) and the X port of the second horizontal lock valve (25.2), and the B port of the horizontal electromagnetic reversing valve (24) is respectively communicated with the Y port of the horizontal lock valve (25.1) and the Y port of the second horizontal lock valve (25.2).

10. The multi-degree-of-freedom active compensation crane hydraulic system according to claim 8, characterized in that: The primary vertical telescopic servo valve group (K) comprises a primary vertical servo valve (31) and a primary vertical electromagnetic reversing valve (32), the three electromagnetic ball valves (22.3) are communicated with the P port of the primary vertical servo valve (31) through the P4 port, the A port of the primary vertical servo valve (31) is communicated with the rodless cavity of the primary vertical telescopic hydraulic cylinder (34), the T port of the primary vertical servo valve (31) is communicated with the oil tank (1) through the cooler (39) and the filter (40), the B port of the primary vertical servo valve (31) is communicated with the A port of the primary vertical lock valve (33), the B port of the primary vertical lock valve (33) is communicated with the rod cavity of the primary vertical telescopic hydraulic cylinder (34), a two displacement sensor (54) is arranged on the primary vertical telescopic hydraulic cylinder (34), and the signal of the two displacement sensor (54) is connected with the primary vertical servo valve (31). The A port of the primary vertical electromagnetic reversing valve (32) is communicated with the control pump (5), the B port of the primary vertical electromagnetic reversing valve (32) is communicated with the oil tank (1), the T port of the primary vertical electromagnetic reversing valve (32) is communicated with the X port of the primary vertical lock valve (33), and the B port of the primary vertical electromagnetic reversing valve (32) is communicated with the Y port of the primary vertical lock valve (33).

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