Counterweight lifting system of crawler crane

Abstract

The utility model discloses a counterweight lifting system of a crawler crane. The counterweight lifting system comprises an electromagnetic directional valve and a balance valve communicated with the electromagnetic directional valve, a lifting synchronous control valve used for controlling the flow of the balance valve flowing into the counterweight oil cylinder is further arranged between the electromagnetic directional valve and the balance valve. Oil outlets A and B of the lifting synchronous control valve are communicated with an oil inlet of the balance valve, an oil port LS is connected with an LS port of the hydraulic pump, and the displacement of the hydraulic pump is changed; and the oil inlets P1 and P2 are connected with an oil outlet of the electromagnetic directional valve. By arranging the lifting synchronous control valve, when the crawler crane is influenced by ground factors and the counterweight is inclined to a certain degree, the lifting synchronous control valve can control the flows flowing into the two oil cylinders to be the same and not to be influenced by loads, so that the two counterweight oil cylinders synchronously extend out, and the counterweight is synchronously lifted; the condition of frequent adjustment during counterweight mounting is avoided, so that the counterweight mounting of the crane is facilitated, and the working efficiency and the counterweight mounting safety are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of telescopic arm crawler cranes, in particular to a crawler crane counterweight lifting system. Background Art

[0002] Telescopic boom crawler cranes are equipped with a counterweight lifting system, which is an auxiliary system for getting on board. It mainly includes a hydraulic cylinder that can lift the counterweight, an electromagnetic reversing valve with a reversing function, a balancing valve that prevents the counterweight from falling due to its own weight, and a hydraulic control system. One end of the counterweight lifting cylinder is connected to the crane turntable, and the other end is connected to the counterweight through a chain.

[0003] At present, the conventional telescopic crane counterweight lifting system is equipped with a counterweight lifting cylinder, which controls the extension and retraction of the cylinder piston rod by changing the oil flow direction through the electromagnetic reversing valve, thereby realizing the counterweight lifting control. In actual work, due to the influence of ground factors (uneven ground), the counterweight has a certain degree of inclination, and the center of gravity of the counterweight is biased to one side of the cylinder. The two cylinders are subjected to different load forces, resulting in the lifting of the two cylinders being out of sync, requiring frequent adjustments, and inconvenient installation. Utility Model Content

[0004] Purpose of the utility model: The utility model aims to provide a crawler crane counterweight lifting system with high efficiency and good safety.

[0005] Technical solution: The crawler crane counterweight lifting system described in the utility model includes an electromagnetic reversing valve and a balancing valve connected thereto; a lifting synchronous control valve for controlling the flow of the balancing valve into the counterweight cylinder is also provided between the electromagnetic reversing valve and the balancing valve; the oil outlets A and B of the lifting synchronous control valve are connected to the oil inlet of the balancing valve, and the oil port LS is connected to the LS port of the hydraulic pump to change the displacement of the hydraulic pump; the oil inlets P1 and P2 are connected to the oil outlet of the electromagnetic reversing valve.

[0006] Wherein, the lifting synchronous control valve includes a switching valve, a one-way valve and a damper.

[0007] The oil inlet of the switching valve is connected to the control port K2, the oil port P1 and the oil port P2.

[0008] Wherein, the oil outlet of the one-way valve is connected to the oil port P1 and the oil port P2.

[0009] The oil inlet and outlet of the damper are respectively connected to the control port K1 and the oil outlet V2 of the switching valve; the oil ports A and B are connected to the oil inlet of the check valve and the oil outlet V1 of the switching valve.

[0010] Among them, the oil port LS of the lifting synchronous control valve is connected to the switching valve V2 port and the damper oil inlet.

[0011] The hydraulic pump and the electromagnetic reversing valve are also provided with a relief valve for limiting pressure.

[0012] Beneficial effect: Compared with the prior art, the utility model has the following advantages: the utility model sets a lifting synchronous control valve, when the crawler crane is affected by ground factors and the counterweight has a certain degree of inclination, the lifting synchronous control valve can control the flow rate flowing into the two cylinders to be the same and not be affected by the load, thereby ensuring that the two counterweight cylinders extend synchronously and the counterweight is lifted synchronously, avoiding frequent adjustments when installing the counterweight, thereby facilitating the installation of the crane's counterweight, improving work efficiency and the safety of counterweight installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the schematic diagram of the conventional counterweight lifting system;

[0014] Figure 2 This is the principle diagram of the counterweight lifting system of the utility model;

[0015] Figure 3 This is the schematic diagram of the rising synchronous control valve. DETAILED DESCRIPTION

[0016] like Figure 1 As shown, the existing crawler telescopic variable amplitude structure and principle are as follows Figure 1 As shown, when the crane is installing the counterweight, the hydraulic pump 01 outputs high-pressure oil to the electromagnetic reversing valve 03, and the relief valve 02 limits the pressure to provide pressure protection for the hydraulic system. The left side of the electromagnetic reversing valve is energized, the valve core is in the left position, and the oil flows into the rodless chamber of the cylinder 06 after passing through the balance valve 05. When the counterweight is tilted, the two cylinders are subjected to different load forces. Due to throttling speed regulation, the cylinder subjected to a small load extends first, and the cylinder subjected to a large load extends later, resulting in different extension speeds of the two cylinders. If the counterweight is to be kept in a horizontal state, the operator needs to control the energization of the electromagnetic reversing valve and change the working state of the electromagnetic reversing valve. The operator needs to observe the tilting state of the counterweight to adjust the working time of the two electromagnetic reversing valves multiple times to ensure that the counterweight cylinders extend synchronously, and the installation process is inconvenient.

[0017] like Figure 2 As shown in the figure, the principle diagram of the counterweight lifting system of the utility model is different from the principle of the counterweight lifting system of the existing telescopic boom crawler crane in that the system adds a lifting synchronous control valve 04 between the electromagnetic reversing valve 03 and the balance valve 05 to control the flow into the two counterweight cylinders 06. The specific working principle is as follows:

[0018] like Figure 3As shown, the A and B ports of the lifting synchronous control valve 04 are oil outlets, connected to the oil inlet of the balance valve; the oil port LS is connected to the LS port of the hydraulic pump to change the displacement of the hydraulic pump; the oil ports P1 and P2 are oil inlets, connected to the oil outlet of the electromagnetic reversing valve 03. The lifting synchronous control valve 04 includes a switching valve 1, a check valve 2 and a damper 3; the oil inlet of the switching valve is connected to the control port K2 and the oil port P1 (P2); the oil outlet of the check valve is connected to the oil port P1 (P2); the oil inlet and outlet of the damper are respectively connected to the control port K1 and the oil outlet V2 of the switching valve; the oil port A (B) is connected to the oil inlet of the check valve and the oil outlet V1 of the switching valve; the oil port LS is connected to the V2 port of the switching valve and the oil inlet of the damper.

[0019] When installing the counterweight on the telescopic boom crawler crane, the hydraulic pump 01 outputs high-pressure oil, the left side of the electromagnetic reversing valve 03 is energized, and the valve core is in the left position. If the counterweight tilts to the left, the load force on the left counterweight cylinder is larger, the left switching valve 1 in the lifting synchronous control valve 04 is in the right position (the valve core moves up to the top), and the right switching valve is in the middle position. At this time, the pressure difference before and after the two electromagnetic reversing valves is equal, the output flow is equal, and the two counterweight cylinders can be extended synchronously without being affected by the load. During the operation of the counterweight lifting system, the function of the lifting synchronous control valve is mainly to control the pressure difference before and after the two electromagnetic reversing valves, thereby ensuring that the output flow is equal, so that the two counterweight lifting cylinders are lifted synchronously and are not affected by load factors.

Claims

1. A crawler crane counterweight lifting system, comprising an electromagnetic reversing valve (03) and a balancing valve (05) connected thereto; characterized in that: A lifting synchronous control valve (04) for controlling the flow rate of the balancing valve (05) into the counterweight cylinder (06) is also provided between the electromagnetic reversing valve (03) and the balancing valve (05); the oil outlets A and B of the lifting synchronous control valve (04) are connected to the oil inlet of the balancing valve (05); the oil port LS is connected to the LS port of the hydraulic pump (01) to change the displacement of the hydraulic pump (01); and the oil inlets P1 and P2 are connected to the oil outlet of the electromagnetic reversing valve (03).

2. A crawler crane counterweight lifting system according to claim 1, characterized in that: The lifting synchronous control valve (04) comprises a switching valve (1), a one-way valve (2) and a damper (3).

3. A crawler crane counterweight lifting system according to claim 2, characterized in that: The oil inlet of the switching valve (1) is connected to the control port K2, the oil port P1 and the oil port P2.

4. A crawler crane counterweight lifting system according to claim 2, characterized in that: The oil outlet of the one-way valve (2) is connected to the oil port P1 and the oil port P2.

5. The crawler crane counterweight lifting system according to claim 2, characterized in that: The oil inlet and outlet of the damper (3) are respectively connected to the control port K1 and the oil outlet V2 of the switching valve (1); the oil ports A and B are connected to the oil inlet of the one-way valve (2) and the oil outlet V1 of the switching valve (1).

6. A crawler crane counterweight lifting system according to claim 5, characterized in that: The oil port LS of the lifting synchronous control valve (04) is connected to the V2 port of the switching valve (1) and the oil inlet of the damper (3).

7. The crawler crane counterweight lifting system according to claim 1, characterized in that: The hydraulic pump (01) and the electromagnetic reversing valve (03) are also provided with an overflow valve (02) for limiting pressure.

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