Hydraulic pilot system and crane

Abstract

The application discloses a hydraulic pilot system and a crane, which comprises a main winding, a luffing, a secondary winding, a telescopic unit and a slewing unit. A shuttle valve is connected to each end of the main winding, the luffing and the slewing unit. Two oil inlets of each shuttle valve are respectively connected to an electric proportional pressure reducing valve and an operating handle. The secondary winding and the telescopic unit are connected in the same oil circuit. Two ends of the secondary winding unit are respectively connected to an oil outlet of a fourth directional valve and a fifth directional valve. Two ends of the telescopic unit are respectively connected to an oil outlet of the fourth directional valve and the fifth directional valve. An oil inlet of the fourth directional valve and an oil inlet of the fifth directional valve are respectively connected to an oil outlet of a fifth shuttle valve and an oil outlet of a sixth shuttle valve. Two oil inlets of the fifth shuttle valve and the sixth shuttle valve are respectively connected to an electric proportional pressure reducing valve and an operating handle. The crane comprises the hydraulic pilot system. The application provides a hydraulic pilot system and a crane, which have a small number of pipelines, a simple system structure and are suitable for hydraulic handle or remote control operation.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic systems, and in particular to a hydraulic pilot system and a crane. Background Art

[0002] Crane hydraulic systems often use hydraulic handle control or remote control operation. The handle control method uses the pilot pressure output by the hydraulic handle to achieve the reversing of the main valve, thereby realizing the operation of getting on the vehicle; remote control operation requires the addition of a remote control module assembly, which consists of multiple electric proportional pressure reducing valves and switching valves, so that the system can achieve movement in ten directions.

[0003] In the prior art, a tire crane controls the hydraulic system through a hydraulic control handle and a remote control switch, such as Figure 1 As shown, the auxiliary reeling and retracting operation begins with pilot oil output from the auxiliary reeling and retracting handle, or from the electric proportional pressure reducing valve in the remote control module assembly. This oil then flows through the two-position four-way valve, shuttle valve, and switching valve assembly to control the oil flow. The pilot oil then flows through the two-position four-way valve solenoid in the switching valve assembly, and then to the two-position three-way valve in the hydraulic proportional directional valve assembly to control the direction of the three-position four-way proportional valve, achieving auxiliary reeling or retracting. The entire system consists of eighteen solenoid valves, four electric proportional pressure reducing valves, six switching valves, and eight solenoid valves in the hydraulic proportional directional valve assembly, controlling ten directional movements. This results in a large number of pipelines, a complex hydraulic system structure, and high costs. Summary of the Invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a hydraulic pilot system and a crane with a small number of pipelines, a simple system structure, and suitable for hydraulic handle or remote control operation.

[0005] Technical solution: To achieve the above-mentioned purpose, the present invention provides a hydraulic pilot system comprising a main reeling unit, a luffing unit, a secondary reeling unit, a telescopic unit, and a rotary unit. The main reeling unit, the luffing unit, and the rotary unit are each connected to a shuttle valve at both ends of the oil circuit. The two oil inlets on each shuttle valve are respectively connected to an electric proportional pressure reducing valve and an operating handle. The system controls the main reeling unit, the luffing unit, and the rotary unit by outputting pilot oil through the corresponding shuttle valve through remote control of each electric proportional pressure reducing valve or by outputting pilot oil through each operating handle.

[0006] The auxiliary reel unit and the telescopic unit are connected in the same oil circuit, the two ends of the auxiliary reel unit are respectively connected to one of the oil outlets of the fourth reversing valve and the fifth reversing valve, the two ends of the telescopic unit are respectively connected to the other oil outlet of the fourth reversing valve and the fifth reversing valve, the oil inlets of the fourth reversing valve and the fifth reversing valve are respectively connected to the oil outlets of the fifth shuttle valve and the sixth shuttle valve, the two oil inlets of the fifth shuttle valve and the sixth shuttle valve are connected to an electric proportional pressure reducing valve and an operating handle, the system outputs pilot oil through the fifth shuttle valve or the sixth shuttle valve by remotely controlling the electric proportional pressure reducing valve or the operating handle connected to the fifth shuttle valve or the sixth shuttle valve, and at the same time switches the working state of the fourth reversing valve or the fifth reversing valve to control the auxiliary reel unit or the telescopic unit.

[0007] Among them, the main roll unit includes a first reversing valve, and two valve stem control chambers are provided on the first reversing valve. The two valve stem control chambers are respectively connected to the oil outlet A of the first shuttle valve and the oil outlet A of the second shuttle valve. The oil inlet P of the first shuttle valve is connected to the oil outlet of the first electric proportional pressure reducing valve. The oil inlet P of the first shuttle valve is connected to the pressure reducing valve on the left side of the main roll operating handle, and the oil inlet P of the second shuttle valve is connected to the pressure reducing valve on the right side of the main roll operating handle. The oil inlet P of the second shuttle valve is connected to the oil outlet of the second electric proportional pressure reducing valve.

[0008] Among them, the amplitude variation unit includes a second reversing valve, and two valve stem control chambers are provided on the second reversing valve. The two valve stem control chambers are respectively connected to the oil outlet A of the third shuttle valve and the oil outlet A of the fourth shuttle valve. The oil inlet P of the third shuttle valve is connected to the oil outlet of the third electric proportional pressure reducing valve. The oil inlet P of the third shuttle valve is connected to the pressure reducing valve on the left side of the amplitude variation operating handle. The oil inlet P of the fourth shuttle valve is connected to the pressure reducing valve on the right side of the amplitude variation operating handle. The oil inlet P of the fourth shuttle valve is connected to the oil outlet of the fourth electric proportional pressure reducing valve.

[0009] Among them, the rotary unit includes a seventh reversing valve, which is provided with two valve stem control chambers. The two valve stem control chambers are respectively connected to the oil outlet A of the seventh shuttle valve and the oil outlet A of the eighth shuttle valve. The oil inlet P of the seventh shuttle valve is connected to the pressure reducing valve on the left side of the rotary operating handle, the oil inlet P of the seventh shuttle valve is connected to the oil outlet of the seventh electric proportional pressure reducing valve, the oil inlet P of the eighth shuttle valve is connected to the pressure reducing valve on the right side of the rotary operating handle, and the oil inlet P of the eighth shuttle valve is connected to the oil outlet of the eighth electric proportional pressure reducing valve.

[0010] Among them, the auxiliary reel unit includes a third reversing valve, and the telescopic unit includes a sixth reversing valve. The third and sixth reversing valves are both provided with two valve stem control chambers. The two valve stem control chambers of the third reversing valve are respectively connected to the A oil ports of the fourth and fifth reversing valves. The two valve stem control chambers of the sixth reversing valve are respectively connected to the B oil ports of the fourth and fifth reversing valves. The P oil port of the fourth reversing valve is connected to the A oil outlet of the fifth shuttle valve, and the P oil port of the fifth reversing valve is connected to the A oil outlet of the sixth shuttle valve.

[0011] The oil inlet P of the fifth shuttle valve is connected to the pressure reducing valve on the left side of the auxiliary reel telescopic operating handle, the oil inlet P of the fifth shuttle valve is connected to the oil outlet of the fifth electric proportional pressure reducing valve, the oil inlet P of the sixth shuttle valve is connected to the oil outlet of the sixth electric proportional pressure reducing valve, and the oil inlet P of the sixth shuttle valve is connected to the pressure reducing valve on the right side of the auxiliary reel telescopic operating handle.

[0012] Among them, the fourth reversing valve and the fifth reversing valve are two-position four-way valves.

[0013] Among them, the first reversing valve, the second reversing valve, the seventh reversing valve, the third reversing valve and the sixth reversing valve are three-position four-way valves.

[0014] The system also includes a first unloading valve and a second unloading valve;

[0015] The first unloading valve oil port A is connected in parallel with one of the valve stem control chambers of the first reversing valve, the second reversing valve, the third reversing valve, and the sixth reversing valve;

[0016] The oil port A of the second unloading valve is respectively connected in parallel with the other valve stem control chamber of the first reversing valve, the second reversing valve, the third reversing valve and the sixth reversing valve;

[0017] By switching the working state of the unloading valve, the valve stems of the first reversing valve, the second reversing valve, the third reversing valve and the sixth reversing valve are controlled to control whether the oil returns to the chamber.

[0018] Among them, the first unloading valve and the second unloading valve are three-position four-way valves.

[0019] The present invention also provides a crane comprising the above hydraulic pilot system.

[0020] Beneficial effects: The present invention has the following advantages: 1. The present invention uses a hydraulic handle or remote control to control the electric proportional pressure reducing valve to output pilot oil, which passes through the shuttle valve to enable the system to perform main reeling, luffing, auxiliary reeling, telescopic, and rotation actions. Among them, the auxiliary reeling unit and the telescopic unit are connected in the same oil circuit. The auxiliary reeling or telescopic action is performed by switching the working states of the fourth reversing valve and the fifth reversing valve. The entire system has a simple structure and is easy to operate.

[0021] 2. Cranes are large-scale engineering machinery that work intermittently and are used in complex environments. By adopting a hydraulic pilot system with a simple structure and fewer pipes and valves, the system failure rate is reduced, the safety of equipment use is improved, and the production and assembly efficiency of the equipment is improved, which facilitates subsequent maintenance.

[0022] 3. The system achieves safety control by connecting two unloading valves in parallel to relieve pressure and protect the system in case of dangerous movements, thereby improving the safety of the system and crane. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is a schematic diagram of the hydraulic system of a tire crane in the prior art;

[0024] Figure 2 This is a schematic diagram of the hydraulic pilot system of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is described in detail below with reference to the embodiments and drawings.

[0026] like Figure 2 As shown, a hydraulic pilot system includes a main reel unit, a luffing unit, an auxiliary reel unit, a telescopic unit, and a rotary unit. The main reel unit, the luffing unit, and the rotary unit are connected to a shuttle valve at both ends of the oil circuit. The two oil inlets on each shuttle valve are connected to an electric proportional pressure reducing valve and an operating handle, respectively. The system controls the main reel unit, the luffing unit, and the rotary unit by outputting pilot oil through the corresponding shuttle valve by remotely controlling each electric proportional pressure reducing valve or by outputting pilot oil through each operating handle.

[0027] The auxiliary winding unit and the telescopic unit are connected in the same oil circuit. The two ends of the auxiliary winding unit are respectively connected to one of the oil outlets of the fourth reversing valve 13 and the fifth reversing valve 14, and the two ends of the telescopic unit are respectively connected to the other oil outlet of the fourth reversing valve 13 and the fifth reversing valve 14. The oil inlets of the fourth reversing valve 13 and the fifth reversing valve 14 are respectively connected to the oil outlets of the fifth shuttle valve 9 and the sixth shuttle valve 10. The two oil inlets of the fifth shuttle valve 9 and the sixth shuttle valve 10 are both connected to an electric proportional pressure reducing valve and an operating handle. The system outputs pilot oil through the fifth shuttle valve 9 or the sixth shuttle valve 10 by remotely controlling the electric proportional pressure reducing valve or the operating handle connected to the fifth shuttle valve 9 or the sixth shuttle valve 10, and at the same time switches the working state of the fourth reversing valve 13 or the fifth reversing valve 14 to control the auxiliary winding unit or the telescopic unit.

[0028] Among them, the main roll unit includes a first reversing valve, and two valve stem control chambers are provided on the first reversing valve. The two valve stem control chambers are respectively connected to the oil outlet A of the first shuttle valve 1 and the oil outlet A of the second shuttle valve 2. The oil inlet P1 of the first shuttle valve 1 is connected to the oil outlet of the first electric proportional pressure reducing valve 3, the oil inlet P2 of the first shuttle valve 1 is connected to the pressure reducing valve on the left side of the main roll operating handle, the oil inlet P1 of the second shuttle valve 2 is connected to the pressure reducing valve on the right side of the main roll operating handle, and the oil inlet P2 of the second shuttle valve 2 is connected to the oil outlet of the second electric proportional pressure reducing valve 4.

[0029] The main roll unit action includes main roll falling and main roll rising. Among them, the main roll falling:

[0030] Handle operation: The pressure reducing valve on the left side of the main reeling handle is actuated to output pilot oil, which passes through the first shuttle valve 1 and the first reversing valve in sequence. After the first reversing valve switches to the working position, the oil is output from the P1 port of the first reversing valve to the A1 port, opening the winch balance valve and driving the winch motor to realize the main reeling;

[0031] Remote control operation: Control the first electric proportional pressure reducing valve 3 to output pilot oil, which passes through the first shuttle valve 1 and the first reversing valve in sequence. After the first reversing valve switches to the working position, the oil is output from the P1 port of the first reversing valve to the A1 port, opening the winch balance valve and driving the winch motor to realize the main winch lowering.

[0032] Among them, the main volume rises:

[0033] Handle operation: The pressure reducing valve on the right side of the main reel operating handle is actuated to output pilot oil, which passes through the second shuttle valve 2 and the first reversing valve in sequence. After the first reversing valve switches to the working position, the oil is output from the P1 port of the first reversing valve to the B1 port, turning on the drive winch motor to realize the main reel lifting;

[0034] Remote control operation: Control the second electric proportional pressure reducing valve 4 to output pilot oil, which passes through the second shuttle valve 2 and the first reversing valve in sequence. After the first reversing valve switches to the working position, the oil is output from the P1 port of the first reversing valve to the B1 port, turning on the drive winch motor to realize the main hoisting.

[0035] Among them, the amplitude variation unit includes a second reversing valve, and two valve stem control chambers are provided on the second reversing valve. The two valve stem control chambers are respectively connected to the oil outlet A of the third shuttle valve 5 and the oil outlet A of the fourth shuttle valve 6. The oil inlet P1 of the third shuttle valve 5 is connected to the oil outlet of the third electric proportional pressure reducing valve 7, the oil inlet P2 of the third shuttle valve 5 is connected to the pressure reducing valve on the left side of the amplitude variation operating handle, the oil inlet P1 of the fourth shuttle valve 6 is connected to the pressure reducing valve on the right side of the amplitude variation operating handle, and the oil inlet P2 of the fourth shuttle valve 6 is connected to the oil outlet of the fourth electric proportional pressure reducing valve 8.

[0036] The luffing unit actions include luffing down and luffing up, among which, luffing down:

[0037] Handle operation: The pressure reducing valve on the left side of the luffing operating handle is actuated to output pilot oil, which passes through the third shuttle valve 5 and the second reversing valve in sequence. After the second reversing valve switches to the working position, the oil is output from the P1 port of the second reversing valve to the A2 port, opening the luffing balancing valve and driving the luffing cylinder to realize the luffing.

[0038] Remote control operation: control the third electric proportional pressure reducing valve 7 to output pilot oil, which passes through the third shuttle valve 5 and the second reversing valve in sequence. After the second reversing valve switches to the working position, the oil is output from the P1 port of the second reversing valve to the A2 port, opening the luffing balancing valve and driving the luffing cylinder to realize the luffing drop.

[0039] Among them, the amplitude is:

[0040] Handle operation: The pressure reducing valve on the right side of the luffing operating handle is actuated to output pilot oil, which passes through the fourth shuttle valve 6 and the second reversing valve in sequence. After the second reversing valve switches to the working position, the oil is output from the P1 port of the second reversing valve to the B2 port, driving the luffing cylinder to operate and realize luffing;

[0041] Remote control operation: control the fourth electric proportional pressure reducing valve 8 to output pilot oil, which passes through the fourth shuttle valve 6 and the second reversing valve in sequence. After the second reversing valve switches to the working position, the oil is output from the P1 port of the second reversing valve to the B2 port, driving the luffing cylinder to move and realize luffing.

[0042] Among them, the auxiliary rewinding unit includes a third reversing valve, and the telescopic unit includes a sixth reversing valve. The third and sixth reversing valves are both provided with two valve stem control chambers. The two valve stem control chambers of the third reversing valve are respectively connected to the A oil ports of the fourth reversing valve 13 and the fifth reversing valve 14. The two valve stem control chambers of the sixth reversing valve are respectively connected to the B oil ports of the fourth reversing valve 13 and the fifth reversing valve 14. The P oil port of the fourth reversing valve 13 is connected to the A oil outlet of the fifth shuttle valve 9, and the P oil port of the fifth reversing valve 14 is connected to the A oil outlet of the sixth shuttle valve 10A.

[0043] The oil inlet P1 of the fifth shuttle valve 9 is connected to the pressure reducing valve on the left side of the auxiliary reel telescopic operating handle, the oil inlet P2 of the fifth shuttle valve 9 is connected to the oil outlet of the fifth electric proportional pressure reducing valve 11, the oil inlet P1 of the sixth shuttle valve 10 is connected to the oil outlet of the sixth electric proportional pressure reducing valve 12, and the oil inlet P2 of the sixth shuttle valve 10 is connected to the pressure reducing valve on the right side of the auxiliary reel telescopic operating handle.

[0044] The fourth reversing valve 13 and the fifth reversing valve 14 are two-position four-way valves.

[0045] The actions of the auxiliary roll unit and the telescopic unit include auxiliary roll falling, auxiliary roll rising, extending and retracting. Among them, the auxiliary roll falling:

[0046] Handle operation: The pressure reducing valve on the left side of the auxiliary reel extension and retraction operating handle is actuated to output pilot oil, which passes through the fifth shuttle valve 9 and the fourth reversing valve 13 in sequence. When the fourth reversing valve 13 is energized, the oil circuit goes to the third reversing valve. After the third reversing valve switches to the working position, the oil is output from the P1 port of the third reversing valve to the A3 port of the third reversing valve, and then the auxiliary reel balance valve is opened, driving the auxiliary reel motor to operate, realizing the auxiliary reeling;

[0047] Remote control operation: control the fifth electric proportional pressure reducing valve 11 to output pilot oil, which passes through the fifth shuttle valve 9 and the fourth reversing valve 13 in sequence. When the fourth reversing valve 13 is energized, the oil circuit goes to the third reversing valve. After the third reversing valve switches to the working position, the oil is output from the P1 port of the third reversing valve to the A3 port of the third reversing valve, and then the auxiliary roll balancing valve is opened to drive the auxiliary roll motor to operate, thereby realizing the auxiliary roll drop.

[0048] Among them, the secondary volume is:

[0049] Handle operation: The pressure reducing valve on the right side of the auxiliary reel telescopic handle is actuated to output pilot oil, which passes through the sixth shuttle valve 10 and the fifth reversing valve 14 in sequence. When the fifth reversing valve 14 is energized, the oil path flows to the third reversing valve. After the third reversing valve switches to the working position, the oil is output from the P1 port of the third reversing valve to the B3 port, turning on the auxiliary reel motor to achieve auxiliary reel lifting.

[0050] Remote control operation: Control the sixth electric proportional pressure reducing valve 12 to output pilot oil, which passes through the sixth shuttle valve 10 and the fifth reversing valve 14 in sequence. When the fifth reversing valve 14 is energized, the oil circuit goes to the third reversing valve. After the third reversing valve switches the working position, the oil is output from the P1 port of the third reversing valve to the B3 port, turning on the auxiliary reel motor to realize the auxiliary reel lifting.

[0051] Among them, stretch:

[0052] Handle operation: The pressure reducing valve on the left side of the auxiliary reel telescopic operating handle is actuated to output pilot oil, which passes through the fifth shuttle valve 9 and the fourth reversing valve 13 in sequence. When the fourth reversing valve 13 is de-energized, the oil circuit flows to the sixth reversing valve. After the sixth reversing valve switches to the working position, the oil is output from the P1 port of the sixth reversing valve to the A4 port of the sixth reversing valve, driving the telescopic cylinder to operate and realize the extension of the boom;

[0053] Remote control operation: Control the fifth electric proportional pressure reducing valve 11 to output pilot oil, which passes through the fifth shuttle valve 9 and the fourth reversing valve 13 in sequence. When the fourth reversing valve 13 is de-energized, the oil circuit goes to the sixth reversing valve. After the sixth reversing valve switches its working position, the oil is output from the P1 port of the sixth reversing valve to the A4 port of the sixth reversing valve, driving the telescopic cylinder to move and realize the extension of the boom.

[0054] Among them, the contraction:

[0055] Handle operation: The pressure reducing valve on the right side of the auxiliary reel telescopic operating handle is actuated to output pilot oil, which passes through the sixth shuttle valve 10 and the fifth reversing valve 14 in sequence. When the fifth reversing valve 14 is de-energized, the oil circuit flows to the sixth reversing valve. After the sixth reversing valve switches to its working position, the oil is output from the P1 port of the sixth reversing valve to the B4 port of the sixth reversing valve, opening the telescopic balancing valve and driving the telescopic cylinder to retract the boom.

[0056] Remote control operation: Control the sixth electric proportional pressure reducing valve 12 to output pilot oil, which passes through the sixth shuttle valve 10 and the fifth reversing valve 14 in sequence. When the fifth reversing valve 14 is de-energized, the oil circuit goes to the sixth reversing valve. After the sixth reversing valve switches its working position, the oil is output from the P1 port of the sixth reversing valve to the B4 port of the sixth reversing valve, opening the telescopic balancing valve and driving the telescopic cylinder to retract the boom.

[0057] Among them, the rotary unit includes a seventh reversing valve, which is provided with two valve stem control chambers. The two valve stem control chambers are respectively connected to the oil outlet A of the seventh shuttle valve 15 and the oil outlet A of the eighth shuttle valve 16. The oil inlet P1 of the seventh shuttle valve 15 is connected to the pressure reducing valve on the left side of the rotary operating handle, the oil inlet P2 of the seventh shuttle valve 15 is connected to the oil outlet of the seventh electric proportional pressure reducing valve 17, the oil inlet P1 of the eighth shuttle valve 16 is connected to the pressure reducing valve on the right side of the rotary operating handle, and the oil inlet P2 of the eighth shuttle valve 16 is connected to the oil outlet of the eighth electric proportional pressure reducing valve 18.

[0058] The rotation action includes left rotation and right rotation, among which the left rotation:

[0059] Handle operation: The pressure reducing valve on the left side of the rotary operating handle is actuated to output pilot oil, which passes through the seventh shuttle valve 15 and the seventh reversing valve in sequence. After the seventh reversing valve switches to the working position, the oil is output from the P port of the seventh reversing valve to the A5 port of the seventh reversing valve, driving the rotary motor to operate and realize left rotation;

[0060] Remote control operation: Control the seventh electric proportional pressure reducing valve 17 to output pilot oil, which passes through the seventh shuttle valve 15 and the seventh reversing valve in sequence. After the seventh reversing valve switches to the working position, the oil is output from the P port of the seventh reversing valve to the A5 port of the seventh reversing valve, driving the rotary motor to move and realize left rotation.

[0061] Among them, right turn:

[0062] Handle operation: The pressure reducing valve on the right side of the rotary operating handle is actuated to output pilot oil, which passes through the eighth shuttle valve 16 and the seventh reversing valve in sequence. After the seventh reversing valve switches to the working position, the oil is output from the P port of the seventh reversing valve to the B5 port of the seventh reversing valve, driving the rotary motor to operate and realize right rotation;

[0063] Remote control operation: Control the eighth electric proportional pressure reducing valve 18 to output pilot oil, which passes through the eighth shuttle valve 16 and the seventh reversing valve in sequence. After the seventh reversing valve switches to the working position, the oil is output from the P port of the seventh reversing valve to the B5 port of the seventh reversing valve, driving the rotary motor to move and realize right rotation.

[0064] The first reversing valve, the second reversing valve, the third reversing valve, the sixth reversing valve and the seventh reversing valve are three-position four-way valves.

[0065] The system also includes a first unloading valve 19 and a second unloading valve 20. The oil port A of the first unloading valve 19 is connected in parallel with one of the valve stem control chambers of the first, second, third, and sixth reversing valves, respectively. The oil port A of the second unloading valve 20 is connected in parallel with another valve stem control chamber of each of the first, second, third, and sixth reversing valves. By switching the operating states of the first unloading valve 19 and the second unloading valve 20, the oil return to the valve stem control chambers of the first, second, third, and sixth reversing valves is controlled. This can promptly shut off dangerous movements, prevent incomplete unloading, and improve system reliability. The first unloading valve 19 and the second unloading valve 20 are three-position, four-way valves.

[0066] The crane described in the present invention includes the hydraulic pilot system described above. The pilot pressure is output through a hydraulic handle pressure reducing valve or through remote control of eight electric proportional pressure reducing valves to control the switching of the working positions of the first reversing valve, the second reversing valve, the third reversing valve, the sixth reversing valve, and the seventh reversing valve, thereby realizing the ten-directional movements of the five units of main winding, boom length adjustment, auxiliary winding, telescopic, and rotation. The system also adds two two-position four-way valves to connect the auxiliary winding unit and the telescopic unit in the same oil circuit. Auxiliary winding or telescopic movement is performed by switching the working states of the two two-position four-way valves. The entire system has a simple structure and is easy to operate.

[0067] Cranes are large-scale engineering machinery that work intermittently and are used in a complex environment. In order to improve the safety and life of the equipment, the hydraulic pilot system used should have a simple structure, fewer pipes and valves, thereby reducing the system failure rate. At the same time, it also improves the equipment production and assembly efficiency and facilitates subsequent maintenance.

Claims

1. A hydraulic pilot system, comprising a main reel unit, a luffing unit, an auxiliary reel unit, a telescopic unit, and a rotary unit, characterized in that: Both ends of the main reel unit, luffing unit, and slewing unit are connected to a shuttle valve through the oil circuit. The two oil inlets on each shuttle valve are connected to an electric proportional pressure reducing valve and an operating handle respectively. The system controls the main reel unit, luffing unit, and slewing unit by remotely controlling the output of pilot oil from each electric proportional pressure reducing valve, or by outputting pilot oil from each operating handle through the corresponding shuttle valve. The auxiliary roll unit and the telescopic unit are connected in the same oil circuit. The auxiliary roll unit includes a third reversing valve, and the telescopic unit includes a sixth reversing valve. The third reversing valve and the sixth reversing valve are both provided with two valve stem control chambers. The two valve stem control chambers of the third reversing valve are respectively connected to the A oil ports of the fourth reversing valve (13) and the fifth reversing valve (14). The two valve stem control chambers of the sixth reversing valve are respectively connected to the B oil ports of the fourth reversing valve (13) and the fifth reversing valve (14). The oil ports are respectively connected to the oil outlets of the fifth shuttle valve (9) and the sixth shuttle valve (10). The two oil inlets of the fifth shuttle valve (9) and the sixth shuttle valve (10) are both connected to an electric proportional pressure reducing valve and an operating handle. The system outputs pilot oil through the fifth shuttle valve (9) or the sixth shuttle valve (10) by remotely controlling the electric proportional pressure reducing valve or the operating handle connected to the fifth shuttle valve (9) or the sixth shuttle valve (10), and simultaneously switches the working state of the fourth reversing valve (13) or the fifth reversing valve (14), thereby controlling the auxiliary winding unit or the telescopic unit.

2. The hydraulic pilot system according to claim 1, characterized in that: The main reel unit comprises a first reversing valve, and two valve stem control chambers are provided on the first reversing valve. The two valve stem control chambers are respectively connected to the oil outlet A of the first shuttle valve (1) and the oil outlet A of the second shuttle valve (2). The oil inlet P1 of the first shuttle valve (1) is connected to the oil outlet of the first electric proportional pressure reducing valve (3). The oil inlet P2 of the first shuttle valve (1) is connected to the pressure reducing valve on the left side of the main reel operating handle. The oil inlet P1 of the second shuttle valve (2) is connected to the pressure reducing valve on the right side of the main reel operating handle. The oil inlet P2 of the second shuttle valve (2) is connected to the oil outlet of the second electric proportional pressure reducing valve (4).

3. The hydraulic pilot system according to claim 1, characterized in that: The amplitude variation unit includes a second reversing valve. The second reversing valve is provided with two valve stem control chambers. The two valve stem control chambers are respectively connected to the oil outlet A of the third shuttle valve (5) and the oil outlet A of the fourth shuttle valve (6). The oil inlet P1 of the third shuttle valve (5) is connected to the oil outlet of the third electric proportional pressure reducing valve (7). The oil inlet P2 of the third shuttle valve (5) is connected to the pressure reducing valve on the left side of the amplitude variation operating handle. The oil inlet P1 of the fourth shuttle valve (6) is connected to the pressure reducing valve on the right side of the amplitude variation operating handle. The oil inlet P2 of the fourth shuttle valve (6) is connected to the oil outlet of the fourth electric proportional pressure reducing valve (8).

4. The hydraulic pilot system according to claim 1, characterized in that: The rotary unit includes a seventh reversing valve. The seventh reversing valve is provided with two valve stem control chambers. The two valve stem control chambers are respectively connected to the oil outlet A of the seventh shuttle valve (15) and the oil outlet A of the eighth shuttle valve (16). The oil inlet P1 of the seventh shuttle valve (15) is connected to the pressure reducing valve on the left side of the rotary operating handle. The oil inlet P2 of the seventh shuttle valve (15) is connected to the oil outlet of the seventh electric proportional pressure reducing valve (17). The oil inlet P1 of the eighth shuttle valve (16) is connected to the pressure reducing valve on the right side of the rotary operating handle. The oil inlet P2 of the eighth shuttle valve (16) is connected to the oil outlet of the eighth electric proportional pressure reducing valve (18).

5. The hydraulic pilot system according to claim 1, characterized in that: The oil port P of the fourth reversing valve (13) is connected to the oil outlet A of the fifth shuttle valve (9), and the oil port P of the fifth reversing valve (14) is connected to the oil outlet A of the sixth shuttle valve (10); The oil inlet P1 of the fifth shuttle valve (9) is connected to the pressure reducing valve on the left side of the auxiliary reel telescopic operating handle, the oil inlet P2 of the fifth shuttle valve (9) is connected to the oil outlet of the fifth electric proportional pressure reducing valve (11), the oil inlet P1 of the sixth shuttle valve (10) is connected to the oil outlet of the sixth electric proportional pressure reducing valve (12), and the oil inlet P2 of the sixth shuttle valve (10) is connected to the pressure reducing valve on the right side of the auxiliary reel telescopic operating handle.

6. The hydraulic pilot system according to claim 1 or 5, characterized in that: The fourth reversing valve (13) and the fifth reversing valve (14) are two-position four-way valves.

7. The hydraulic pilot system according to any one of claims 2 to 5, characterized in that: The first reversing valve, the second reversing valve, the seventh reversing valve, the third reversing valve and the sixth reversing valve are three-position four-way valves.

8. The hydraulic pilot system according to any one of claims 1 to 3 or 5, characterized in that: The system further includes a first unloading valve (19) and a second unloading valve (20); The oil port A of the first unloading valve (19) is connected in parallel to one of the valve stem control chambers of the first reversing valve, the second reversing valve, the third reversing valve, and the sixth reversing valve; The oil port A of the second unloading valve (20) is connected in parallel with the other valve stem control chamber of the first reversing valve, the second reversing valve, the third reversing valve, and the sixth reversing valve respectively; By switching the working state of the unloading valve, the valve stems of the first reversing valve, the second reversing valve, the third reversing valve and the sixth reversing valve are controlled to control whether the oil returns to the chamber.

9. The hydraulic pilot system according to claim 8, characterized in that: The first unloading valve (19) and the second unloading valve (20) are two-position four-way valves.

10. A crane, characterized in that: A hydraulic pilot system comprising any one of claims 1 to 5 or 9.

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