High-flow jacking system of tower crane and operation method of high-flow jacking system

Abstract

The invention discloses a tower crane high-flow jacking system and an operation method thereof, and belongs to the technical field of tower crane control. The system comprises an oil tank, a parallel type oil supply pump set, a reversing valve and a jacking oil cylinder, an oil inlet of the parallel type oil supply pump set is communicated with the oil tank, the reversing valve is connected with an oil outlet of the parallel type oil supply pump set through an oil inlet pipe and communicated with the oil tank through an oil return pipe, and the oil inlet pipe is communicated with the oil return pipe through a safety valve. A rod cavity of the jacking oil cylinder is connected with the reversing valve through a high-pressure oil pipe A, and a rodless cavity of the jacking oil cylinder is connected with the reversing valve through a high-pressure oil pipe B. A plurality of hydraulic pumps are connected in parallel to form the parallel type oil supply pump set so as to drive the jacking oil cylinder to work, the power requirement of the jacking system for a single motor and the hydraulic pump is remarkably reduced, the parallel type oil supply pump set adopting the domestic hydraulic pump can provide large-flow output larger than or equal to 30 L / min under the working condition of the high output pressure larger than or equal to 42 MPa, and the working efficiency of the jacking system is improved. And therefore, the requirement of the self-climbing tower crane on a matched jacking system is met.

Description

TECHNICAL FIELD

[0001] The present application relates to a tower crane large-flow jacking system and a running method thereof, and belongs to the technical field of tower crane control. BACKGROUND

[0002] A certain self-climbing tower crane requires a matched jacking system for controlling its lifting to provide a large-flow output of ≥30L / min under a high-output pressure condition of ≥42MPa.

[0003] However, the product of the output pressure p and the flow Q of a traditional single-motor-driven hydraulic pump station is limited to the rated power P of a single motor, that is, P=p×Q. When the jacking system needs to simultaneously achieve a very high output pressure p and a very large output flow Q, that is, the jacking system is used to jack a heavy tower crane and has certain requirements on the jacking speed, the power requirements of a single motor and a hydraulic pump are extremely high, and a domestic hydraulic pump cannot meet the demand for a large-flow output of ≥30L / min under the condition of an output pressure of ≥42MPa.

[0004] Therefore, how to make the jacking system provide a large-flow output of ≥30L / min under a high-output pressure condition of ≥42MPa is a technical problem to be solved by those skilled in the art. SUMMARY

[0005] To solve the above technical problems, the present application provides a tower crane large-flow jacking system and a running method thereof.

[0006] The present application is achieved by the following technical solutions: A tower crane large-flow jacking system comprises an oil tank, a parallel oil supply pump set, a reversing valve and a jacking oil cylinder. The oil inlet of the parallel oil supply pump set is communicated with the oil tank. The reversing valve is connected with the oil outlet of the parallel oil supply pump set through an oil inlet pipe and communicated with the oil tank through an oil return pipe. The oil inlet pipe is communicated with the oil return pipe through a safety valve. The rod cavity of the jacking oil cylinder is connected with the reversing valve through a high-pressure oil pipe A, and the rodless cavity is connected with the reversing valve through a high-pressure oil pipe B.

[0007] The parallel oil supply pump set comprises two parallel-connected hydraulic pumps. The oil inlets of the two hydraulic pumps are respectively communicated with the oil tank through coarse oil filters, and the oil outlets are respectively communicated with the oil inlet pipe through check valves. The two hydraulic pumps are respectively driven by electric motors.

[0008] The rated power of the electric motor is not less than 15kW, and the rated flow of the hydraulic pump is not less than 15L / min.

[0009] The effective volume of the oil tank is not less than 185L.

[0010] The reversing valve is a H-shaped three-position four-way manual reversing valve, the P port is communicated with the oil inlet pipe, the T port is connected with the oil return pipe, the A port is communicated with the high-pressure oil pipe A, and the B port is communicated with the high-pressure oil pipe B.

[0011] An oil return filter is installed on the oil return pipe close to the oil tank.

[0012] The oil inlet pipe is communicated with the oil return pipe through a lifting overflow valve.

[0013] A pressure gauge is installed on the oil inlet pipe.

[0014] The high-pressure oil pipe A is communicated with the oil return pipe through a descending overflow valve.

[0015] A running method of a tower crane large-flow lifting system, comprising the following running modes: The lifting oil cylinder piston rod lifting mode: the reversing valve is manually operated to the left working position, two electric motors are started to drive two hydraulic pumps to run, the hydraulic oil output by the two hydraulic pumps is combined after flowing through the one-way valves and then flows into the oil inlet pipe, part of the hydraulic oil in the oil inlet pipe enters the oil return pipe through the lifting overflow valve and then flows back to the oil tank, so that the smoothness and stability of the lifting oil cylinder piston rod lifting process are improved, and the other part of the hydraulic oil enters the rodless cavity of the lifting oil cylinder through the B port of the reversing valve P port and the high-pressure oil pipe B, at the same time, the hydraulic oil in the rod cavity of the lifting oil cylinder flows into the oil tank through the high-pressure oil pipe A, the A port, the T port and the oil return pipe in turn, and the lifting oil cylinder piston rod lifting is realized. The lifting oil cylinder piston rod descending mode: the reversing valve is manually operated to the right working position, two electric motors are started to drive two hydraulic pumps to run, the hydraulic oil output by the two hydraulic pumps is combined after flowing through the one-way valves and then flows into the oil inlet pipe, and then flows into the high-pressure oil pipe A through the P port and the A port in turn, part of the hydraulic oil in the high-pressure oil pipe A flows to the oil tank through the descending overflow valve and the oil return pipe, so that the hydraulic oil flow entering the rod cavity of the lifting oil cylinder is reduced, the descending speed of the lifting oil cylinder piston rod is reduced, stable descending is realized, and the other part of the hydraulic oil enters the rod cavity of the lifting oil cylinder, at the same time, the hydraulic oil in the rodless cavity of the lifting oil cylinder flows into the oil tank through the high-pressure oil pipe B, the B port, the T port and the oil return pipe in turn, and the lifting oil cylinder piston rod descending is realized. The unloading mode: the reversing valve is manually operated to the middle working position, two electric motors are started to drive two hydraulic pumps to run, the hydraulic oil output by the two hydraulic pumps is combined after flowing through the one-way valves and then flows into the oil inlet pipe, and then flows into the oil tank through the P port, the T port and the oil return pipe in turn.

[0016] The beneficial effects of the present application are: 1. By connecting multiple hydraulic pumps in parallel to form a parallel oil supply pump group to drive the lifting cylinder, the power requirements of the lifting system on a single motor and hydraulic pump are significantly reduced. This allows the parallel oil supply pump group using domestically produced hydraulic pumps to provide a large flow rate of ≥30L / min under high output pressure conditions of ≥42MPa, thereby meeting the requirements of self-climbing tower cranes for their supporting lifting systems.

[0017] 2. Two independent electric motors are used to drive two hydraulic pumps of the same displacement. The hydraulic oil output from the two hydraulic pumps flows through check valves and then merges to form the total output port of the parallel oil supply pump group, which can provide a large flow rate of 30L / min under a high output pressure of 42MPa.

[0018] 3. The parallel oil supply pump set includes two hydraulic pumps connected in parallel, which gives the parallel oil supply pump set redundancy. When one of the motors or hydraulic pumps fails, the other hydraulic pump can still operate normally, allowing the tower crane to continue to perform lifting and lowering functions, thus improving the safety of tower crane operation.

[0019] 4. A one-way valve is installed between each hydraulic pump and the oil inlet pipe to prevent high-pressure hydraulic oil from backflowing and damaging the hydraulic pump, or to prevent the hydraulic oil output from one hydraulic pump from interfering with the normal operation of another hydraulic pump.

[0020] 5. The oil inlet pipe is connected to the return oil pipe through the lifting relief valve. When the piston rod of the lifting cylinder is in the lifting mode, a portion of the hydraulic oil in the oil inlet pipe enters the return oil pipe through the lifting relief valve and then flows back to the oil tank. The lifting relief valve plays a role in smoothing the oil pressure in the oil inlet pipe, which can improve the smoothness and stability of the lifting process of the piston rod of the lifting cylinder.

[0021] 6. High-pressure oil pipe A is connected to the return oil pipe through a descent relief valve. When the piston rod of the lifting cylinder is in the descent mode, a portion of the hydraulic oil in high-pressure oil pipe A flows to the oil tank through the descent relief valve and the return oil pipe to reduce the flow of hydraulic oil entering the rod chamber of the lifting cylinder, reduce the descent speed of the piston rod of the lifting cylinder, avoid the piston rod from falling sharply, and thus achieve a smooth descent. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention.

[0023] In the diagram: 1-oil tank, 2-coarse oil filter, 3-hydraulic pump, 4-motor, 5-check valve, 6-oil inlet pipe, 7-pressure gauge, 8-lowering relief valve, 9-high pressure oil pipe A, 10-lifting cylinder, 11-high pressure oil pipe B, 12-directional valve, 13-return oil pipe, 14-lifting relief valve, 15-safety valve, 16-return oil filter. Detailed Implementation

[0024] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0025] like Figure 1 As shown, the tower crane high-flow jacking system of the present invention includes an oil tank 1, a parallel oil supply pump group, a reversing valve 12, and a jacking cylinder 10. The oil inlet of the parallel oil supply pump group is connected to the oil tank 1. The reversing valve 12 is connected to the oil outlet of the parallel oil supply pump group through an oil inlet pipe 6 and is connected to the oil tank 1 through a return oil pipe 13. The oil inlet pipe 6 is connected to the return oil pipe 13 through a safety valve 15. The rod chamber of the jacking cylinder 10 is connected to the reversing valve 12 through a high-pressure oil pipe A9, and the rodless chamber is connected to the reversing valve 12 through a high-pressure oil pipe B11.

[0026] Specifically, multiple hydraulic pumps 3 are connected in parallel to form a parallel oil supply pump group to drive the lifting cylinder 10 to work. This significantly reduces the power requirements of the lifting system on a single electric motor 4 and hydraulic pump 3, enabling the parallel oil supply pump group using domestically produced hydraulic pumps 3 to provide a large flow output of ≥30L / min under high output pressure conditions of ≥42MPa, thereby meeting the requirements of self-climbing tower cranes for their supporting lifting systems.

[0027] The rated pressure of safety valve 15 is 45 MPa.

[0028] The parallel oil supply pump group includes two hydraulic pumps 3 connected in parallel. The oil inlets of the two hydraulic pumps 3 are connected to the oil tank 1 through the coarse oil filter 2, and the oil outlets are connected to the oil inlet pipe 6 through the check valve 5. The two hydraulic pumps 3 are driven by electric motors 4.

[0029] Specifically, two independent electric motors 4 (rated power of 15kW) are used to drive two hydraulic pumps 3 with the same displacement (rated flow rate of 15L / min). The hydraulic oil output from the two hydraulic pumps 3 flows through the check valve 5 and then merges to form the total output port of the parallel oil supply pump group, which can provide a large flow rate of 30L / min under the high output pressure of 42MPa.

[0030] The parallel oil supply pump set includes two hydraulic pumps 3 connected in parallel, which gives the parallel oil supply pump set redundancy. When one of the motors 4 or hydraulic pumps 3 fails, the other hydraulic pump 3 can still operate normally, so that the tower crane can continue to perform lifting and lowering functions, thus improving the safety of tower crane operation.

[0031] A one-way valve 5 is installed between each hydraulic pump 3 and the oil inlet pipe 6 to prevent high-pressure hydraulic oil from backflowing and damaging the hydraulic pump 3, or to prevent the hydraulic oil output by one hydraulic pump 3 from interfering with the normal operation of another hydraulic pump 3.

[0032] The rated power of the electric motor 4 is not less than 15kW, and the rated flow rate of the hydraulic pump 3 is not less than 15L / min.

[0033] The effective volume of the oil tank 1 is not less than 185L. The hydraulic oil in the oil tank 1 is anti-wear hydraulic oil.

[0034] The reversing valve 12 is an H-type three-position four-way manual reversing valve. Its P port is connected to the oil inlet pipe 6, its T port is connected to the oil return pipe 13, its A port is connected to the high-pressure oil pipe A9, and its B port is connected to the high-pressure oil pipe B11.

[0035] An oil return filter 16 is installed on the oil return pipe 13 near the oil tank 1.

[0036] The oil inlet pipe 6 is connected to the oil return pipe 13 via the lifting overflow valve 14.

[0037] A pressure gauge 7 is installed on the oil inlet pipe 6.

[0038] The high-pressure oil pipe A9 is connected to the return oil pipe 13 through the lowering relief valve 8.

[0039] An operating method for a tower crane high-flow-rate jacking system includes the following operating modes: Lifting cylinder 10 piston rod lifting mode: Manually operate the reversing valve 12 to the left working position to start two electric motors 4 to drive two hydraulic pumps 3. The hydraulic oil output from the two hydraulic pumps 3 flows through the check valves 5 and then merges into the inlet pipe 6. A portion of the hydraulic oil in the inlet pipe 6 enters the return pipe 13 through the lifting relief valve 14 and then flows back to the oil tank 1 to improve the smoothness and stability of the lifting process of the piston rod of the lifting cylinder 10. The other portion of the hydraulic oil enters the B port through the P port of the reversing valve 12, and then enters the rodless chamber of the lifting cylinder 10 through the high-pressure oil pipe B11. At the same time, the hydraulic oil in the rod chamber of the lifting cylinder 10 flows sequentially through the high-pressure oil pipe A9, port A, port T and the return pipe 13 before entering the oil tank 1, realizing the lifting of the piston rod of the lifting cylinder 10. The maximum working pressure in the lifting mode is 42MPa.

[0040] The piston rod of the lifting cylinder 10 descends in the following mode: Manually operate the directional valve 12 to the right working position to start two electric motors 4, driving two hydraulic pumps 3. The hydraulic oil output from the two pumps 3 flows through check valves 5 and then merges into the inlet pipe 6. It then flows sequentially through port P and port A before entering the high-pressure oil pipe A9. A portion of the hydraulic oil in high-pressure oil pipe A9 flows through the descending relief valve 8 and the return pipe 13 to the oil tank 1, reducing the flow of hydraulic oil into the rod chamber of the lifting cylinder 10 and lowering the piston rod's descent speed for a smooth descent. The remaining hydraulic oil enters the rod chamber of the lifting cylinder 10. Simultaneously, the hydraulic oil in the rodless chamber of the lifting cylinder 10 flows sequentially through high-pressure oil pipe B11, port B, port T, and the return pipe 13 before entering the oil tank 1, thus lowering the piston rod of the lifting cylinder 10. The maximum working pressure in the descent mode is 9 MPa.

[0041] Unloading mode: Manually operate the directional valve 12 to the middle working position, start the two motors 4 to drive the two hydraulic pumps 3 to run. The hydraulic oil output by the two hydraulic pumps 3 flows through the check valve 5 and then merges into the oil inlet pipe 6. Then it flows through the P port, T port and return oil pipe 13 in sequence and enters the oil tank 1.

Claims

1. A high-flow-rate tower crane jacking system, characterized in that: The system includes an oil tank (1), a parallel oil supply pump group, a reversing valve (12), and a lifting cylinder (10). The oil inlet of the parallel oil supply pump group is connected to the oil tank (1). The reversing valve (12) is connected to the oil outlet of the parallel oil supply pump group through the oil inlet pipe (6) and is connected to the oil tank (1) through the oil return pipe (13). The oil inlet pipe (6) is connected to the oil return pipe (13) through the safety valve (15). The rod chamber of the lifting cylinder (10) is connected to the reversing valve (12) through the high-pressure oil pipe A (9), and the rodless chamber is connected to the reversing valve (12) through the high-pressure oil pipe B (11).

2. The tower crane high-flow-rate jacking system as described in claim 1, characterized in that: The parallel oil supply pump group includes two hydraulic pumps (3) connected in parallel. The oil inlets of the two hydraulic pumps (3) are connected to the oil tank (1) through the coarse oil filter (2), and the oil outlets are connected to the oil inlet pipe (6) through the check valve (5). The two hydraulic pumps (3) are driven by electric motors (4).

3. The tower crane high-flow-rate jacking system as described in claim 2, characterized in that: The rated power of the electric motor (4) is not less than 15kW, and the rated flow rate of the hydraulic pump (3) is not less than 15L / min.

4. The tower crane high-flow-rate jacking system as described in claim 3, characterized in that: The effective volume of the oil tank (1) is not less than 185L.

5. The tower crane high-flow-rate jacking system as described in claim 1, characterized in that: The reversing valve (12) is an H-type three-position four-way manual reversing valve. Its P port is connected to the oil inlet pipe (6), its T port is connected to the oil return pipe (13), its A port is connected to the high-pressure oil pipe A (9), and its B port is connected to the high-pressure oil pipe B (11).

6. The tower crane high-flow-rate jacking system as described in claim 1, characterized in that: A return oil filter (16) is installed on the return oil pipe (13) near the oil tank (1).

7. The tower crane high-flow-rate jacking system as described in claim 1, characterized in that: The oil inlet pipe (6) is connected to the oil return pipe (13) through the lifting overflow valve (14).

8. The tower crane high-flow-rate jacking system as described in claim 1, characterized in that: A pressure gauge (7) is installed on the oil inlet pipe (6).

9. The tower crane high-flow-rate jacking system as described in claim 1, characterized in that: The high-pressure oil pipe A (9) is connected to the return oil pipe (13) through the downflow relief valve (8).

10. A method for operating a high-flow-rate tower crane jacking system, characterized in that: Including the following operating modes: Lifting cylinder (10) piston rod lifting mode: Manually operate the reversing valve (12) to the left working position, start two motors (4) to drive two hydraulic pumps (3) to run, the hydraulic oil output by the two hydraulic pumps (3) flows through the check valve (5) and then merges into the oil inlet pipe (6). Part of the hydraulic oil in the oil inlet pipe (6) enters the return oil pipe (13) through the lifting overflow valve (14) and then flows back to the oil tank (1) to improve the smoothness and stability of the lifting process of the piston rod of the lifting cylinder (10). Another part of the hydraulic oil enters the B port through the P port of the reversing valve (12) and then enters the rodless chamber of the lifting cylinder (10) through the high pressure oil pipe B (11). At the same time, the hydraulic oil in the rod chamber of the lifting cylinder (10) flows through the high pressure oil pipe A (9), port A, port T and return oil pipe (13) in sequence and then enters the oil tank (1) to realize the lifting of the piston rod of the lifting cylinder (10). The piston rod of the lifting cylinder (10) descends in the following mode: The directional valve (12) is manually operated to the right working position, and the two motors (4) are started to drive the two hydraulic pumps (3) to run. The hydraulic oil output by the two hydraulic pumps (3) flows through the check valve (5) and then merges into the oil inlet pipe (6). Then it flows through the P port and the A port in sequence and enters the high pressure oil pipe A (9). A part of the hydraulic oil in the high pressure oil pipe A (9) flows to the oil tank (1) through the descending overflow valve (8) and the return oil pipe (13) to reduce the flow of hydraulic oil entering the rod chamber of the lifting cylinder (10), reduce the descending speed of the piston rod of the lifting cylinder (10), and achieve a smooth descent. The other part of the hydraulic oil enters the rod chamber of the lifting cylinder (10). At the same time, the hydraulic oil in the rodless chamber of the lifting cylinder (10) flows through the high pressure oil pipe B (11), the B port, the T port and the return oil pipe (13) in sequence and enters the oil tank (1) to achieve the descent of the piston rod of the lifting cylinder (10). Unloading mode: Manually operate the reversing valve (12) to the middle working position, start the two motors (4) to drive the two hydraulic pumps (3) to run. The hydraulic oil output by the two hydraulic pumps (3) flows through the check valve (5) and then merges into the oil inlet pipe (6). Then it flows through the P port, T port and return oil pipe (13) in sequence and enters the oil tank (1).

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