Multi-way valve and force limit integrated operation control system

Abstract

The present invention belongs to the field of hydraulic control, and specifically relates to a multi-way valve and a force limit integrated operation control system for a truck-mounted crane, wherein the multi-way valve comprises an oil inlet and return unloading link, an amplitude change control link, a winch control link, a telescopic control link and a slewing control link, wherein the oil inlet and return unloading link comprises a two-position two-way hydraulically controlled reversing valve connected between an oil inlet P of the multi-way valve and an oil return port T of the multi-way valve, wherein a spring chamber and a non-spring chamber of the two-position two-way hydraulically controlled reversing valve are both connected to the oil inlet P of the multi-way valve, and a main overflow valve and an electromagnetic switching valve are arranged in parallel between the spring chamber of the two-position two-way hydraulically controlled reversing valve and the oil return port T of the multi-way valve; displacement sensors are integrated for the valve core end positions of the telescopic reversing valve, the amplitude change reversing valve and the winch reversing valve that require force limit action to realize the torque limit function, thereby realizing a high degree of integration of functional modules.

Description

Technical Field

[0001] The invention belongs to the field of hydraulic control, and in particular relates to a multi-way valve and force limit integrated operation control system for a truck-mounted crane. Background Art

[0002] The straight-arm truck crane needs to repeatedly perform luffing and winching actions during the crane start-up and recovery phases to achieve the crane's deployment and retraction. This control method is time-consuming, labor-intensive and has poor economic efficiency. At the same time, in terms of crane safety, it is necessary to separately add an electromagnetic unloading valve and hydraulic pipeline to achieve the torque limiting function of the straight-arm truck crane. The integration and reliability of this separately added torque control system need to be optimized. Summary of the invention

[0003] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a multi-way valve for a truck-mounted crane, which realizes the torque limiting function by integrating a two-position two-way hydraulically controlled reversing valve, a main overflow valve and an electromagnetic switching valve, and providing displacement sensors at the valve core end connections of the variable amplitude reversing valve, the winch reversing valve and the telescopic reversing valve, thereby achieving a high degree of integration of functional modules.

[0004] The present invention is realized by the following technical scheme: a multi-way valve for a truck-mounted crane, the multi-way valve comprises an oil inlet and return unloading link, a boom control link, a winch control link, a telescopic control link and a slewing control link, the oil inlet and return unloading link comprises a two-position two-way hydraulically controlled reversing valve connected between an oil inlet P of the multi-way valve and an oil return port T of the multi-way valve, a spring chamber and a non-spring chamber of the two-position two-way hydraulically controlled reversing valve are both connected to the oil inlet P of the multi-way valve, a main overflow valve and an electromagnetic switching valve are arranged in parallel between the spring chamber of the two-position two-way hydraulically controlled reversing valve and the oil return port T of the multi-way valve;

[0005] The amplitude control unit includes an amplitude reversing valve, the oil inlet H1 of the amplitude reversing valve is connected to the oil inlet P of the multi-way valve, the oil return port H2 of the amplitude reversing valve is connected to the oil return port T of the multi-way valve, the working oil port H3 of the amplitude reversing valve is connected to the working oil port B2 of the multi-way valve, and the working oil port H4 of the amplitude reversing valve is connected to the working oil port A2 of the multi-way valve;

[0006] The winch control unit includes a winch reversing valve, the oil inlet I1 of the winch reversing valve is connected to the oil inlet P of the multi-way valve, the oil return port I2 of the winch reversing valve is connected to the oil return port T of the multi-way valve, the working oil port I3 of the winch reversing valve is connected to the working oil port B3 of the multi-way valve, and the working oil port I4 of the winch reversing valve is connected to the working oil port A3 of the multi-way valve;

[0007] The telescopic control link includes a telescopic reversing valve, the oil inlet J1 of the telescopic reversing valve is connected to the oil inlet P of the multi-way valve, the oil return port J2 of the telescopic reversing valve is connected to the oil return port T of the multi-way valve, the working oil port J3 of the telescopic reversing valve is connected to the working oil port B4 of the multi-way valve, and the working oil port J4 of the telescopic reversing valve is connected to the working oil port A4 of the multi-way valve;

[0008] The rotary control link includes a rotary switching valve, the oil inlet K1 of the rotary switching valve is connected to the oil inlet P of the multi-way valve, the oil return port K2 of the rotary switching valve is connected to the oil return port T of the multi-way valve, the working oil port K3 of the rotary switching valve is connected to the working oil port B5 of the multi-way valve, and the working oil port K4 of the rotary switching valve is connected to the working oil port A5 of the multi-way valve;

[0009] Displacement sensors are provided at the connection points of the valve core ends of the variable amplitude reversing valve, the hoisting reversing valve and the telescopic reversing valve.

[0010] Furthermore, damping holes are provided between the spring chamber of the two-position two-way hydraulically controlled reversing valve and the oil inlet P of the multi-way valve, and between the non-spring chamber of the two-position two-way hydraulically controlled reversing valve and the oil inlet P of the multi-way valve.

[0011] Furthermore, the multi-way valve also includes a compound control unit, which includes a compound reversing valve, the oil inlet G1 of the compound reversing valve is connected to the oil inlet P of the multi-way valve, the oil return port G2 of the compound reversing valve is connected to the oil return port T of the multi-way valve, the working oil port G3 of the compound reversing valve is connected to the working oil port B1 of the multi-way valve, and the working oil port G4 of the compound reversing valve is connected to the working oil port A1 of the multi-way valve.

[0012] Furthermore, one-way valves are provided at the oil inlet G1 of the composite reversing valve, the oil inlet H1 of the variable amplitude reversing valve, the oil inlet I1 of the hoisting reversing valve, the oil inlet J1 of the telescopic reversing valve and the oil inlet K1 of the swing reversing valve.

[0013] The present invention also provides a force limit integrated operation control system using the above-mentioned multi-way valve, wherein the oil inlet P of the multi-way valve is connected to the oil tank through a hydraulic pump, and the oil return port T of the multi-way valve is connected to the oil tank; the working oil port A2 of the multi-way valve is connected to the rod chamber of the boom cylinder, and the working oil port B2 of the multi-way valve is connected to the rodless chamber of the boom cylinder; the working oil port A3 of the multi-way valve is connected to the falling chamber of the winch mechanism, and the working oil port B3 of the multi-way valve is connected to the lifting chamber of the winch mechanism; the working oil port A4 of the multi-way valve is connected to the rod chamber of the telescopic cylinder, and the working oil port B4 of the multi-way valve is connected to the rodless chamber of the telescopic cylinder; the working oil port A5 of the multi-way valve is connected to the forward rotation chamber of the rotary mechanism, and the working oil port B5 of the multi-way valve is connected to the reverse rotation chamber of the rotary mechanism.

[0014] Furthermore, balancing valves are provided between the rod chamber and the rodless chamber of the boom cylinder, between the lifting chamber and the lowering chamber of the hoisting mechanism, and between the rod chamber and the rodless chamber of the telescopic cylinder.

[0015] Furthermore, a second secondary overflow valve is provided between the working oil port I3 of the winch reversing valve and the return oil port T of the multi-way valve, as well as between the working oil port I4 of the winch reversing valve and the return oil port T of the multi-way valve; a third secondary overflow valve is provided between the working oil port K3 of the return reversing valve and the return oil port T of the multi-way valve, as well as between the working oil port K4 of the return reversing valve and the return oil port T of the multi-way valve.

[0016] Furthermore, the multi-way valve also includes a compound control link, which includes a compound reversing valve, the oil inlet G1 of the compound reversing valve is connected to the oil inlet P of the multi-way valve, the oil return port G2 of the compound reversing valve is connected to the oil return port T of the multi-way valve, the working oil port G3 of the compound reversing valve is connected to the working oil port B1 of the multi-way valve, and the working oil port G4 of the compound reversing valve is connected to the working oil port A1 of the multi-way valve; the working oil port A1 of the multi-way valve is connected to the oil port C1 of the three-position six-way hydraulic control reversing valve, and the working oil port B1 of the multi-way valve is connected to the oil port The oil port C2 is connected; the oil port C1 of the three-position six-way hydraulically controlled reversing valve is also connected to the left spring chamber of the three-position six-way hydraulically controlled reversing valve, and the oil port C2 of the three-position six-way hydraulically controlled reversing valve is also connected to the right spring chamber of the three-position six-way hydraulically controlled reversing valve; the oil port C3 of the three-position six-way hydraulically controlled reversing valve is connected to the rod chamber of the boom cylinder, the oil port C4 of the three-position six-way hydraulically controlled reversing valve is connected to the lifting chamber of the winch mechanism, the oil port C5 of the three-position six-way hydraulically controlled reversing valve is connected to the rodless chamber of the boom cylinder, and the oil port C6 of the three-position six-way hydraulically controlled reversing valve is connected to the falling chamber of the winch mechanism.

[0017] Furthermore, a first secondary relief valve is provided between the working oil port G4 of the composite reversing valve and the oil return port T of the multi-way valve.

[0018] Furthermore, the three-position six-way hydraulically controlled directional control valve is integrated into the composite control link of the multi-way valve.

[0019] The valve core end position of the telescopic reversing valve, the valve core end position of the variable amplitude reversing valve and the valve core end position of the winch reversing valve are integrated with displacement sensors to monitor the three force limit amplification directions of variable amplitude drop, winch rise and telescopic extension. When the valve core is in these three action directions, if the electrical system detects that the torque limit state is required, a signal is given to the electromagnetic switching valve to make it lose power and unload at low pressure. When the valve core remains in the force limit amplification direction, the displacement sensor will always give the electromagnetic switching valve feedback signal in the force limit unloading state, and there is no action in the force limit direction. When the valve core is pushed in the direction of force limit reduction, the displacement sensor will give the electromagnetic switching valve feedback signal to restore the electromagnetic switching valve to the power-on state, so that it can act in the reverse direction. The multi-way valve is integrated with unloading function and displacement monitoring function to realize integrated control of force limit.

[0020] The beneficial effect of the present invention is that the torque limiting function is realized by integrating the electromagnetic switching valve on the main overflow valve side of the multi-way valve and the valve core end position of the telescopic reversing valve that requires force limiting action, the valve core end position of the variable amplitude reversing valve and the valve core end position of the winch reversing valve, thereby realizing a high degree of integration of functional modules.

[0021] The multi-way valve realizes the compound action of hoisting and luffing by adding a compound control link and cooperating with the configured three-position six-way hydraulically controlled reversing valve, so that the crane can be quickly deployed and retracted, thus optimizing the crane operation control method. The compound action of any two actions can also be defined according to customer needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the multi-way valve of the present invention;

[0023] Figure 2 It is a hydraulic principle diagram of the multi-way valve of the present invention;

[0024] Figure 3 The invention adopts a force-limited integrated operation control system of a multi-way valve;

[0025] In the figure, 1, oil inlet and return unloading link, 11, two-position two-way hydraulic control reversing valve, 12, main relief valve, 13, electromagnetic switching valve, 14, damping hole I, 15, damping hole II, 2, compound control link, 21, compound reversing valve, 22, check valve I, 23, first secondary relief valve, 3, variable amplitude control link, 31, variable amplitude reversing valve, 32, check valve II, 33, variable amplitude link displacement sensor, 4, winch control link, 41, winch reversing valve, 42, check valve III, 43, winch link displacement sensor, 44, second secondary Overflow valve I, 45, second secondary overflow valve II, 5, telescopic control link, 51, telescopic reversing valve, 52, one-way valve IV, 53, telescopic link displacement sensor, 6, rotary control link, 61, rotary reversing valve, 62, one-way valve V, 63, third secondary overflow valve I, 64, third secondary overflow valve II, 7, three-position six-way hydraulically controlled reversing valve, 71, damping hole III, 72, damping hole IV, 101, hydraulic pump, 102, boom cylinder, 103, winch mechanism, 104, telescopic cylinder, 105, rotary mechanism. DETAILED DESCRIPTION

[0026] The present invention is further described below with reference to the accompanying drawings and embodiments.

[0027] like Figure 1 and Figure 2 As shown, a multi-way valve for a truck-mounted crane comprises an oil inlet and return unloading link 1, a boom control link 3, a winch control link 4, a telescopic control link 5 and a slewing control link 6.

[0028] The oil inlet and return unloading link 1 includes a two-position two-way hydraulically controlled reversing valve 11 connected between the oil inlet P of the multi-way valve and the oil return port T of the multi-way valve. The oil port P1 of the two-position two-way hydraulically controlled reversing valve 11 is connected to the oil inlet P of the multi-way valve. The oil port P1 of the two-position two-way hydraulically controlled reversing valve 11 is also connected to the spring chamber P3 of the two-position two-way hydraulically controlled reversing valve 11 and the non-spring chamber P2 of the two-position two-way hydraulically controlled reversing valve 11. A damping hole I14 is provided on the oil path from the oil port P1 of the two-position two-way hydraulically controlled reversing valve 11 to the non-spring chamber P2 of the two-position two-way hydraulically controlled reversing valve 11. A damping hole II15 is provided on the oil path from the oil port P1 of the two-position two-way hydraulically controlled reversing valve 11 to the spring chamber P3 of the two-position two-way hydraulically controlled reversing valve 11.

[0029] The oil inlet and return unloading link 1 also includes a main relief valve 12 and an electromagnetic switching valve 13. The oil port P4 of the main relief valve 12 is connected to the spring chamber P3 of the two-position two-way hydraulic control reversing valve 11, and the oil port T1 of the main relief valve 12 is connected to the oil return port T of the multi-way valve. The oil port P5 of the electromagnetic switching valve 13 is connected to the spring chamber P3 of the two-position two-way hydraulic control reversing valve 11, and the oil port T2 of the electromagnetic switching valve 13 is connected to the oil return port T of the multi-way valve.

[0030] The amplitude control link 3 includes an amplitude reversing valve 31 and a check valve II 32. The oil inlet H1 of the amplitude reversing valve 31 is connected to the oil inlet P of the multi-way valve, the oil return port H2 of the amplitude reversing valve 31 is connected to the oil return port T of the multi-way valve, the working oil port H3 of the amplitude reversing valve 31 is connected to the working oil port B2 of the multi-way valve, and the working oil port H4 of the amplitude reversing valve 31 is connected to the working oil port A2 of the multi-way valve. The check valve II 32 is arranged at the oil inlet H1 of the amplitude reversing valve 31, so that the hydraulic oil can only flow from the oil inlet P of the multi-way valve to the oil inlet H1 of the amplitude reversing valve 31 in one direction. The end connection of the valve core of the amplitude reversing valve 31 is provided with an amplitude link displacement sensor 33.

[0031] The hoist control link 4 includes a hoist reversing valve 41 and a one-way valve III 42. The oil inlet I1 of the hoist reversing valve 41 is connected to the oil inlet P of the multi-way valve, the oil return port I2 of the hoist reversing valve 41 is connected to the oil return port T of the multi-way valve, the working oil port I3 of the hoist reversing valve 41 is connected to the working oil port B3 of the multi-way valve, and the working oil port I4 of the hoist reversing valve 41 is connected to the working oil port A3 of the multi-way valve. The one-way valve III 42 is arranged at the oil inlet I1 of the hoist reversing valve 41, so that the hydraulic oil can only flow from the oil inlet P of the multi-way valve to the oil inlet I1 of the hoist reversing valve 41 in one direction. A hoist link displacement sensor 43 is arranged at the connection of the valve core end of the hoist reversing valve 41.

[0032] The telescopic control link 5 includes a telescopic reversing valve 51 and a one-way valve IV52. The oil inlet J1 of the telescopic reversing valve 51 is connected to the oil inlet P of the multi-way valve, the oil return port J2 of the telescopic reversing valve 51 is connected to the oil return port T of the multi-way valve, the working oil port J3 of the telescopic reversing valve 51 is connected to the working oil port B4 of the multi-way valve, and the working oil port J4 of the telescopic reversing valve 51 is connected to the working oil port A4 of the multi-way valve. The one-way valve IV52 is arranged at the oil inlet J1 of the telescopic reversing valve 51, so that the hydraulic oil can only flow from the oil inlet P of the multi-way valve to the oil inlet J1 of the telescopic reversing valve 51 in one direction. A telescopic link displacement sensor 53 is arranged at the connection of the valve core end of the telescopic reversing valve 51.

[0033] The rotary control link 6 includes a rotary switching valve 61 and a check valve V62. The oil inlet K1 of the rotary switching valve 61 is connected to the oil inlet P of the multi-way valve, the oil return port K2 of the rotary switching valve 61 is connected to the oil return port T of the multi-way valve, the working oil port K3 of the rotary switching valve 61 is connected to the working oil port B5 of the multi-way valve, and the working oil port K4 of the rotary switching valve 61 is connected to the working oil port A5 of the multi-way valve. The check valve V62 is arranged at the oil inlet K1 of the rotary switching valve 61, so that the hydraulic oil can only flow from the oil inlet P of the multi-way valve to the oil inlet K1 of the rotary switching valve 61 in one direction.

[0034] When the system does not reach the rated pressure, the oil port P4 of the main relief valve 12 is disconnected from the oil port T1 of the main relief valve 12, the solenoid switching valve 13 is in the energized state, the oil port P5 of the solenoid switching valve 13 is disconnected from the oil port T2 of the solenoid switching valve 13, the two-position two-way hydraulically controlled reversing valve 11 is in the right position, and the hydraulic oil can normally provide oil pressure to the boom control link 3, the winch control link 4, the telescopic control link 5 and the slewing control link 6 from the oil inlet P of the multi-way valve.

[0035] When the system reaches the rated pressure, the main relief valve 12 acts as a safety valve, the oil port P4 of the main relief valve 12 to the oil port T1 of the main relief valve 12 is opened, the solenoid switching valve 13 is in an energized state, and the oil port P5 of the solenoid switching valve 13 to the oil port T2 of the solenoid switching valve 13 is disconnected. The spring chamber P3 of the two-position two-way hydraulically controlled reversing valve 11 returns oil at high pressure through the oil port P4 of the main relief valve 12, and the oil port P1 of the two-position two-way hydraulically controlled reversing valve 11 circulates through the damping hole Ⅱ15. The pressure at the oil port P1 of the two-position two-way hydraulically controlled reversing valve 11 is higher than the pressure at the spring chamber P3 of the two-position two-way hydraulically controlled reversing valve 11, and the pressure at the oil port P1 of the two-position two-way hydraulically controlled reversing valve 11 acts on the non-spring chamber P2 of the two-position two-way hydraulically controlled reversing valve 11 through the damping hole Ⅰ14. The pressure at the oil port P1 of the two-position two-way hydraulically controlled reversing valve 11 is equal to the pressure at the non-spring chamber P2 of the two-position two-way hydraulically controlled reversing valve 11. At this time, the oil at the non-spring chamber P2 of the two-position two-way hydraulically controlled reversing valve 11 is higher than the sum of the pressure at the spring chamber P3 of the two-position two-way hydraulically controlled reversing valve 11 and the smaller spring force. The system is in a rated pressure unloading state, and the protection system is in the rated pressure range.

[0036] When the system reaches the force limit state, the main relief valve 12 does not reach the set pressure, the oil port P4 of the main relief valve 12 is disconnected from the oil port T1 of the main relief valve 12, the solenoid switching valve 13 is in a power-off state, the solenoid switching valve 13 is switched to the left position, the oil port P5 of the solenoid switching valve 13 is connected to T2 of the solenoid switching valve 13, and the spring chamber P3 of the two-position two-way hydraulic control reversing valve 11 directly returns oil. Without considering the back pressure of the return oil pipeline, the pressure is zero. At this time, the two-position two-way hydraulic control reversing valve 11 returns oil directly to the spring chamber P3 of the two-position two-way hydraulic control reversing valve 11. The pressure at the non-spring chamber P2 of the two-position two-way hydraulically controlled directional valve 11 connected to the oil port P1 of the directional valve 11 is also zero. The oil pressure at the oil inlet P of the multi-way valve only needs to overcome the smaller spring force of the spring chamber of the two-position two-way hydraulically controlled directional valve 11. The two-position two-way hydraulically controlled directional valve 11 is switched to the left position to achieve low-pressure oil leakage. The system cannot build up a large pressure to provide oil pressure to the boom control link 3, the winch control link 4, the telescopic control link 5 and the slewing control link 6, thereby realizing the torque limiting function.

[0037] As an improvement of this embodiment, the multi-way valve further includes a compound control link 2 and a one-way valve I22. The compound control link 2 includes a compound reversing valve 21. The oil inlet G1 of the compound reversing valve 21 is connected to the oil inlet P of the multi-way valve, the oil return port G2 of the compound reversing valve 21 is connected to the oil return port T of the multi-way valve, the working oil port G3 of the compound reversing valve 21 is connected to the working oil port B1 of the multi-way valve, and the working oil port G4 of the compound reversing valve 21 is connected to the working oil port A1 of the multi-way valve. The one-way valve I22 is arranged at the oil inlet G1 of the compound reversing valve 21, so that the hydraulic oil can only flow from the oil inlet P of the multi-way valve to the oil inlet G1 of the compound reversing valve 21 in one direction. The compound control link 2 can be used to cooperate with the three-position six-way hydraulic control reversing valve to realize the compound action of the variable-length oil cylinder and the hoisting mechanism.

[0038] like Figures 1 to 3 As shown, the present invention also provides a force-limited integrated operation control system using the above-mentioned multi-way valve, wherein the oil inlet P of the multi-way valve is connected to the oil tank through the hydraulic pump 101, and the oil return port T of the multi-way valve is connected to the oil tank through the oil filter. The working oil port A2 of the multi-way valve is connected to the rod chamber of the variable-length oil cylinder 102, and the working oil port B2 of the multi-way valve is connected to the rodless chamber of the variable-length oil cylinder 102; the working oil port A3 of the multi-way valve is connected to the falling chamber of the hoisting mechanism 103, and the working oil port B3 of the multi-way valve is connected to the lifting chamber of the hoisting mechanism 103; the working oil port A4 of the multi-way valve is connected to the rod chamber of the telescopic oil cylinder 104, and the working oil port B4 of the multi-way valve is connected to the rodless chamber of the telescopic oil cylinder 102; the working oil port A5 of the multi-way valve is connected to the forward rotation chamber of the rotary mechanism 105, and the working oil port B5 of the multi-way valve is connected to the reverse rotation chamber of the rotary mechanism 105.

[0039] When the crane is in action for luffing and lifting weights, operate the luffing control link 3 to push the luffing reversing valve 31 to the lower position, and the oil at the oil inlet P of the multi-way valve flows through the one-way valve II 32 to the oil inlet H1 of the luffing reversing valve 31, and then connects the working oil port H4 of the luffing reversing valve 31 and the working oil port A2 of the multi-way valve to the rod chamber of the luffing cylinder 102. At this time, the torque gradually increases during the luffing and lifting operation. When the electrical control system detects that it is in a state where torque limitation is required, it sends a signal to the solenoid switching valve 13 to de-energize it, and the oil port P5 of the solenoid switching valve 13 is connected to the oil port T2 of the solenoid switching valve 13, so that the crane achieves low-pressure oil leakage. At this time, the luffing reversing valve 31 is kept in the lower position, the crane cannot build up a large pressure, and the luffing and lifting operation does not occur. Afterwards, the amplitude-changing reversing valve 31 moves back to the neutral position, and the electrical control system monitors that the amplitude-changing displacement sensor 33 is no longer in the direction of increasing torque. At the same time, a signal is fed back to the solenoid switching valve 13 to energize it, and the oil port P5 of the solenoid switching valve 13 is disconnected from the oil port T2 of the solenoid switching valve 13. The two-position two-way hydraulically controlled reversing valve 11 is in the right position, and the oil can normally provide oil pressure to the crane operation from the oil inlet P of the multi-way valve.

[0040] When the crane is in operation to hoist and lift weights, operate the hoist control link 4 to push the hoist reversing valve 41 to the upper position, and the oil at the oil inlet P of the multi-way valve passes through the one-way valve III 42 to the oil inlet I1 of the hoist reversing valve 41, and then passes through the working oil port I3 of the hoist reversing valve 41 and the working oil port B3 of the multi-way valve to the lifting chamber of the hoisting mechanism 103. At this time, the torque gradually increases during the hoisting and lifting operation. When the electrical control system detects that it is in a state requiring torque limitation, it sends a signal to the solenoid switching valve 13 to make it lose power, and the oil port P5 of the solenoid switching valve 13 is connected to the oil port T2 of the solenoid switching valve 13, and the crane achieves low-pressure oil leakage. At this time, the hoist reversing valve 41 is kept in the upper position, the crane cannot build up a large pressure, and the hoisting does not move. Afterwards, the winch reversing valve 41 moves back to the neutral position, and the electrical control system monitors that the winch joint displacement sensor 43 is no longer in the direction of increasing torque. At the same time, it feeds back a signal to the solenoid switching valve 13 to energize it, and the oil port P5 of the solenoid switching valve 13 is disconnected from the oil port T2 of the solenoid switching valve 13. The two-position two-way hydraulically controlled reversing valve 11 is in the right position, and the oil can normally provide oil pressure to the crane operation from the oil inlet P of the multi-way valve.

[0041] When the crane moves to extend its arm and lift heavy objects, operate the telescopic control link 5 to push the telescopic reversing valve 51 to the upper position, and the oil at the oil inlet P of the multi-way valve passes through the one-way valve IV52 to the oil inlet J1 of the telescopic reversing valve 51, and then passes through the working oil port J3 of the telescopic reversing valve 51 and the working oil port B4 of the multi-way valve to the rodless chamber of the telescopic cylinder 104. At this time, the torque gradually increases during the arm extension and lifting operation. When the electrical control system detects that it is in a state requiring torque limitation, it sends a signal to the solenoid switching valve 13 to make it lose power, and the oil port P5 of the solenoid switching valve 13 is connected to the oil port T2 of the solenoid switching valve 13, so that the crane achieves low-pressure oil leakage. At this time, the telescopic reversing valve 51 is kept in the upper position, the crane cannot build up a large pressure, and the arm extension has no action. Afterwards, the telescopic reversing valve 51 moves back to the middle position, and the electrical control system monitors that the telescopic joint displacement sensor 53 is no longer in the direction of increasing torque. At the same time, it feeds back a signal to the solenoid switching valve 13 to energize it, and the oil port P5 of the solenoid switching valve 13 is disconnected from the oil port T2 of the solenoid switching valve 13. The two-position two-way hydraulically controlled reversing valve 11 is in the right position, and the oil can normally provide oil pressure to the crane operation from the oil inlet P of the multi-way valve.

[0042] As an improvement of this embodiment, a balancing valve is provided between the rod chamber of the luffing cylinder 102 and the rodless chamber of the luffing cylinder 102, between the lifting chamber of the hoisting mechanism 103 and the lowering chamber of the hoisting mechanism 103, and between the rod chamber of the telescopic cylinder 104 and the rodless chamber of the telescopic cylinder 104. The above-mentioned balancing valves are provided to prevent slippage when the crane is statically loaded and play a role in load retention. Figure 3As shown, a shuttle valve is built into the balance valve between the lifting chamber of the hoisting mechanism 103 and the falling chamber of the hoisting mechanism 103, and the hoisting mechanism 103 is connected to the built-in shuttle valve. When the hoisting is in motion, the hoisting brake is opened through the shuttle valve to make the hoisting move, and when the hoisting stops, the hoisting brake oil pressure is unloaded through the shuttle valve to stop the hoisting.

[0043] like Figure 2 and Figure 3 As shown, a second secondary relief valve I44 is provided between the working oil port I3 of the hoisting reversing valve 41 and the oil return port T of the multi-way valve, and a second secondary relief valve II45 is provided between the working oil port I4 of the hoisting reversing valve 41 and the oil return port T of the multi-way valve. The second secondary relief valve I44 and the second secondary relief valve II45 can independently adjust the system rated working pressure of the hoisting control link 3 according to actual working conditions.

[0044] like Figure 2 and Figure 3 As shown, a third secondary relief valve II 64 is provided between the working oil port K3 of the swing switching valve 61 and the oil return port T of the multi-way valve, and a third secondary relief valve I 63 is provided between the working oil port K4 of the swing switching valve 61 and the oil return port T of the multi-way valve. The third secondary relief valve I 63 and the third secondary relief valve II 64 can adjust the system rated working pressure of the swing control link 3 separately according to the actual working conditions.

[0045] Based on the aforementioned force-limited integrated operation control system, Figure 2 and Figure 3 As shown, the multi-way valve also includes a compound control link 2, which includes a compound reversing valve 21. The oil inlet G1 of the compound reversing valve 21 is connected to the oil inlet P of the multi-way valve, the oil return port G2 of the compound reversing valve 21 is connected to the oil return port T of the multi-way valve, the working oil port G3 of the compound reversing valve 21 is connected to the working oil port B1 of the multi-way valve, and the working oil port G4 of the compound reversing valve 21 is connected to the working oil port A1 of the multi-way valve; the working oil port A1 of the multi-way valve is connected to the oil port C1 of the three-position six-way hydraulically controlled reversing valve 7, and the working oil port B1 of the multi-way valve is connected to the oil port C2 of the three-position six-way hydraulically controlled reversing valve 7; the oil port C1 of the three-position six-way hydraulically controlled reversing valve 7 is also connected to the left spring chamber C11 of the three-position six-way hydraulically controlled reversing valve 7, and the oil port C2 of the three-position six-way hydraulically controlled reversing valve 7 is also connected to the right spring chamber C21 of the three-position six-way hydraulically controlled reversing valve 7. The oil port C3 of the three-position six-way hydraulically controlled reversing valve 7 is connected to the rod chamber of the boom cylinder 102, the oil port C4 of the three-position six-way hydraulically controlled reversing valve 7 is connected to the lifting chamber of the winch mechanism 103, the oil port C5 of the three-position six-way hydraulically controlled reversing valve 7 is connected to the rodless chamber of the boom cylinder 102, and the oil port C6 of the three-position six-way hydraulically controlled reversing valve 7 is connected to the falling chamber of the winch mechanism 103.

[0046] At the beginning of the crane no-load operation phase, operate the compound control link 2 to push the compound reversing valve 21 to the upper position, and the oil at the oil inlet P of the multi-way valve flows through the one-way valve Ⅰ22 to the oil inlet G1 of the compound reversing valve 21, and then enters the oil port C2 of the three-position six-way hydraulically controlled reversing valve 7 through the working oil port G3 of the compound reversing valve 21 and the working oil port B1 of the multi-way valve. Because the middle position of the three-position six-way hydraulically controlled reversing valve 7 is in the cut-off state, part of the oil flows through the pilot oil circuit through the damping hole Ⅳ72 to the right spring chamber C21 of the three-position six-way hydraulically controlled reversing valve 7, thereby pushing the three-position six-way hydraulically controlled reversing valve 7 to the right position, and the oil port C2 of the three-position six-way hydraulically controlled reversing valve 7 is connected to the oil port C2 of the three-position six-way hydraulically controlled reversing valve 7. The oil port C6 and the oil port C5 of the three-position six-way hydraulically controlled reversing valve 7 allow the oil pressure to act on the rodless chamber of the boom cylinder 102 and the falling chamber of the hoisting mechanism 103, while the rod chamber of the boom cylinder 102 and the lifting chamber of the hoisting mechanism 103 are respectively merged into the oil port C1 of the three-position six-way hydraulically controlled reversing valve 7 through the oil port C3 of the three-position six-way hydraulically controlled reversing valve 7 and the oil port C4 of the three-position six-way hydraulically controlled reversing valve 7, and then through the working oil port A1 of the multi-way valve and the working oil port G4 of the compound reversing valve 21 to the return oil port G2 of the compound reversing valve 21, and the return oil is sent to the oil tank through the return oil port T of the multi-way valve, thereby realizing the compound action of boom lifting and hoisting falling, and realizing the commonly used unfolding operation of the crane.

[0047] During the final recovery operation of the crane without load, operate the compound control link 2 to push the compound reversing valve 21 to the lower position, and the oil at the oil inlet P of the multi-way valve flows through the one-way valve Ⅰ22 to the oil inlet G1 of the compound reversing valve 21, and then enters the oil port C1 of the three-position six-way hydraulically controlled reversing valve 7 through the working oil port G4 of the compound reversing valve 21 and the working oil port A1 of the multi-way valve. Because the middle position of the three-position six-way hydraulically controlled reversing valve 7 is in the cut-off state, part of the oil flows through the pilot oil circuit through the damping hole Ⅲ71 to the left spring chamber C11 of the three-position six-way hydraulically controlled reversing valve 7, thereby pushing the three-position six-way hydraulically controlled reversing valve 7 to the left position, and the oil port C1 of the three-position six-way hydraulically controlled reversing valve 7 is connected to the three-position six-way hydraulically controlled reversing valve 7. The oil port C4 and the oil port C3 of the three-position six-way hydraulically controlled reversing valve 7 make the oil pressure act on the rod chamber of the boom cylinder 102 and the rising chamber of the hoisting mechanism 103, while the rodless chamber of the boom cylinder 102 and the falling chamber of the hoisting mechanism 103 are respectively merged into the oil port C2 of the three-position six-way hydraulically controlled reversing valve 7 through the oil port C5 of the three-position six-way hydraulically controlled reversing valve 7 and the oil port C6 of the three-position six-way hydraulically controlled reversing valve 7, and then reach the oil return port G2 of the compound reversing valve 21 through the working oil port B1 of the multi-way valve and the working oil port G3 of the compound reversing valve 21, and the return oil reaches the oil tank through the oil return port T of the multi-way valve, thereby realizing the compound action of boom dropping and hoisting rising, and realizing the commonly used recovery operation of the crane.

[0048] As a preferred embodiment of the present invention, a first secondary relief valve 23 is provided between the working oil port G4 of the compound reversing valve 21 and the return oil port T of the multi-way valve. The first secondary relief valve 23 can independently adjust the system rated working pressure of the compound control link 2 according to actual working conditions.

[0049] The three-position six-way hydraulically controlled directional control valve 7 can be integrated into the composite control link 2 of the multi-way valve; the three-position six-way hydraulically controlled directional control valve 7 can also be changed into an electromagnetic switching valve for control.

Claims

1. A multi-way valve for a truck-mounted crane, characterized in that: The multi-way valve comprises an oil inlet and return unloading link (1), a boom control link (3), a winch control link (4), a telescopic control link (5) and a slewing control link (6); the oil inlet and return unloading link (1) comprises a two-position two-way hydraulically controlled reversing valve (11) connected between an oil inlet port P of the multi-way valve and an oil return port T of the multi-way valve; a spring chamber and a non-spring chamber of the two-position two-way hydraulically controlled reversing valve (11) are both connected to the oil inlet port P of the multi-way valve; a main overflow valve (12) and an electromagnetic switching valve (13) are arranged in parallel between the spring chamber of the two-position two-way hydraulically controlled reversing valve (11) and the oil return port T of the multi-way valve; The amplitude control link (3) comprises an amplitude reversing valve (31), an oil inlet H1 of the amplitude reversing valve (31) being connected to an oil inlet P of the multi-way valve, an oil return port H2 of the amplitude reversing valve (31) being connected to an oil return port T of the multi-way valve, a working oil port H3 of the amplitude reversing valve (31) being connected to a working oil port B2 of the multi-way valve, and a working oil port H4 of the amplitude reversing valve (31) being connected to a working oil port A2 of the multi-way valve; The winch control unit (4) comprises a winch reversing valve (41), an oil inlet I1 of the winch reversing valve (41) being connected to an oil inlet P of the multi-way valve, an oil return port I2 of the winch reversing valve (41) being connected to an oil return port T of the multi-way valve, a working oil port I3 of the winch reversing valve (41) being connected to a working oil port B3 of the multi-way valve, and a working oil port I4 of the winch reversing valve (41) being connected to a working oil port A3 of the multi-way valve; The telescopic control link (5) comprises a telescopic reversing valve (51), an oil inlet J1 of the telescopic reversing valve (51) being connected to an oil inlet P of the multi-way valve, an oil return port J2 of the telescopic reversing valve (51) being connected to an oil return port T of the multi-way valve, a working oil port J3 of the telescopic reversing valve (51) being connected to a working oil port B4 of the multi-way valve, and a working oil port J4 of the telescopic reversing valve (51) being connected to a working oil port A4 of the multi-way valve; The rotary control link (6) comprises a rotary reversing valve (61), an oil inlet K1 of the rotary reversing valve (61) being connected to an oil inlet P of the multi-way valve, an oil return port K2 of the rotary reversing valve (61) being connected to an oil return port T of the multi-way valve, a working oil port K3 of the rotary reversing valve (61) being connected to a working oil port B5 of the multi-way valve, and a working oil port K4 of the rotary reversing valve (61) being connected to a working oil port A5 of the multi-way valve; Displacement sensors are provided at the connection points of the valve core ends of the variable amplitude reversing valve (31), the hoisting reversing valve (41) and the telescopic reversing valve (51); The oil port of the two-position two-way hydraulically controlled reversing valve (11) is connected to the oil inlet P of the multi-way valve, and the oil port of the two-position two-way hydraulically controlled reversing valve (11) is also connected to the spring chamber of the two-position two-way hydraulically controlled reversing valve (11) and the non-spring chamber of the two-position two-way hydraulically controlled reversing valve (11); a damping hole I (14) is provided on the oil path from the oil port of the two-position two-way hydraulically controlled reversing valve (11) to the non-spring chamber of the two-position two-way hydraulically controlled reversing valve (11); a damping hole II (15) is provided on the oil path from the oil port of the two-position two-way hydraulically controlled reversing valve (11) to the spring chamber of the two-position two-way hydraulically controlled reversing valve (11); The oil port of the main overflow valve (12) is in communication with the spring chamber of the two-position two-way hydraulically controlled reversing valve (11), and the oil port T1 of the main overflow valve (12) is in communication with the oil return port T of the multi-way valve; the oil port of the electromagnetic switching valve (13) is in communication with the spring chamber of the two-position two-way hydraulically controlled reversing valve (11), and the oil port T2 of the electromagnetic switching valve (13) is in communication with the oil return port T of the multi-way valve.

2. The multi-way valve for a truck mounted crane according to claim 1, characterized in that: The multi-way valve further comprises a compound control unit (2), the compound control unit (2) comprising a compound reversing valve (21), an oil inlet G1 of the compound reversing valve (21) being connected to an oil inlet P of the multi-way valve, an oil return port G2 of the compound reversing valve (21) being connected to an oil return port T of the multi-way valve, a working oil port G3 of the compound reversing valve (21) being connected to a working oil port B1 of the multi-way valve, and a working oil port G4 of the compound reversing valve (21) being connected to a working oil port A1 of the multi-way valve.

3. The multi-way valve for a truck mounted crane according to claim 2, characterized in that: One-way valves are provided at the oil inlet G1 of the composite reversing valve (21), the oil inlet H1 of the variable amplitude reversing valve (31), the oil inlet I1 of the hoisting reversing valve (41), the oil inlet J1 of the telescopic reversing valve (51), and the oil inlet K1 of the swing reversing valve (61).

4. A force-limited integrated operation control system using the multi-way valve according to claim 1, characterized in that: The oil inlet P of the multi-way valve is connected to the oil tank through the hydraulic pump (101), and the oil return port T of the multi-way valve is connected to the oil tank; the working oil port A2 of the multi-way valve is connected to the rod chamber of the boom cylinder (102), and the working oil port B2 of the multi-way valve is connected to the rodless chamber of the boom cylinder (102); the working oil port A3 of the multi-way valve is connected to the lowering chamber of the hoisting mechanism (103), and the working oil port B3 of the multi-way valve is connected to the lifting chamber of the hoisting mechanism (103); the working oil port A4 of the multi-way valve is connected to the rod chamber of the telescopic cylinder (104), and the working oil port B4 of the multi-way valve is connected to the rodless chamber of the telescopic cylinder (104); the working oil port A5 of the multi-way valve is connected to the forward rotation chamber of the slewing mechanism (105), and the working oil port B5 of the multi-way valve is connected to the reverse rotation chamber of the slewing mechanism (105).

5. The force-limited integrated operation control system according to claim 4 is characterized in that: Balance valves are provided between the rod chamber of the luffing cylinder (102) and the rodless chamber of the luffing cylinder (102), between the lifting chamber of the hoisting mechanism (103) and the lowering chamber of the hoisting mechanism (103), and between the rod chamber of the telescopic cylinder (104) and the rodless chamber of the telescopic cylinder (104).

6. The force-limited integrated operation control system according to claim 4, characterized in that: A second secondary relief valve is provided between the working oil port I3 of the hoisting reversing valve (41) and the oil return port T of the multi-way valve, as well as between the working oil port I4 of the hoisting reversing valve (41) and the oil return port T of the multi-way valve; a third secondary relief valve is provided between the working oil port K3 of the return reversing valve (61) and the oil return port T of the multi-way valve, as well as between the working oil port K4 of the return reversing valve (61) and the oil return port T of the multi-way valve.

7. The force-limited integrated operation control system according to claim 4 is characterized in that: The multi-way valve further comprises a compound control unit (2), the compound control unit (2) comprising a compound reversing valve (21), an oil inlet G1 of the compound reversing valve (21) being connected to an oil inlet P of the multi-way valve, an oil return port G2 of the compound reversing valve (21) being connected to an oil return port T of the multi-way valve, a working oil port G3 of the compound reversing valve (21) being connected to a working oil port B1 of the multi-way valve, a working oil port G4 of the compound reversing valve (21) being connected to a working oil port A1 of the multi-way valve; the working oil port A1 of the multi-way valve being connected to an oil port C1 of a three-position six-way hydraulically controlled reversing valve (7), and the working oil port B1 of the multi-way valve being connected to an oil port C2 of a three-position six-way hydraulically controlled reversing valve (7); The oil port C1 of the three-position six-way hydraulically controlled reversing valve (7) is also in communication with the left spring chamber of the three-position six-way hydraulically controlled reversing valve (7), and the oil port C2 of the three-position six-way hydraulically controlled reversing valve (7) is also in communication with the right spring chamber of the three-position six-way hydraulically controlled reversing valve (7); the oil port C3 of the three-position six-way hydraulically controlled reversing valve (7) is in communication with the rod chamber of the variable-length oil cylinder (102), the oil port C4 of the three-position six-way hydraulically controlled reversing valve (7) is in communication with the lifting chamber of the hoisting mechanism (103), the oil port C5 of the three-position six-way hydraulically controlled reversing valve (7) is in communication with the rodless chamber of the variable-length oil cylinder (102), and the oil port C6 of the three-position six-way hydraulically controlled reversing valve (7) is in communication with the lowering chamber of the hoisting mechanism (103).

8. The force-limited integrated operation control system according to claim 7, characterized in that: A first secondary relief valve is provided between the working oil port G4 of the composite reversing valve (21) and the oil return port T of the multi-way valve.

9. The force-limited integrated operation control system according to claim 7, characterized in that: The three-position six-way hydraulically controlled directional control valve (7) is integrated on the composite control link (2) of the multi-way valve.

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