Crane power control system

Abstract

The invention discloses a crane power control system which comprises a reversing valve, a pressure oil outlet of the reversing valve is connected with a first pipeline and a second pipeline through a flow dividing and collecting valve, the first pipeline and the second pipeline are connected with operation oil supply cavities of two oil cylinders respectively, and a two-way overflow valve is arranged between the first pipeline and the second pipeline. A one-way valve is arranged at an inlet of the two-way overflow valve and controls pressure oil to enter the two-way overflow valve from the reversing one-way valve. In the invention, the one-way valve can reduce the impact on the overflow valve when the double-oil-cylinder system is started, prolong the service life of the overflow valve and improve the synchronization precision, and the oil cylinder on the other side can quickly move in place after the oil cylinder on one side is in place when asynchronization occurs.

Description

Technical Field

[0001] The invention relates to a hydraulic control device, in particular to a crane power control system. Background Art

[0002] For large-tonnage cranes, counterweights often require two cylinders to be installed. The installation process requires high synchronization of the cylinders. The existing dual-cylinder system often uses a diverter and collector valve for synchronization control. This system is simple in composition and low in cost, but the diverter and collector valve itself has poor accuracy. When the loads of the two cylinders are different, the asynchronous deviation of the cylinders increases, affecting the service life of the cylinders, and there is a risk of the counterweight block slipping.

[0003] The invention patent application with publication number CN103470560A discloses a crane and its power hydraulic system, in which a two-way overflow valve is arranged between a main oil inlet pipeline and a main oil return pipeline, and oil with a higher pressure in the main oil inlet pipeline and the main oil return pipeline flows to oil with a lower pressure to reduce the pressure difference between the two oil circuits. Since the crane counterweight system generally adopts a low-cost quantitative pump control, the control valve is also a switch valve. In the current solution, during the start-stop stage of the counterweight system, the diversion accuracy is poor and there is a greater impact on the overflow valve, which affects the service life of the overflow valve. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a crane power system to improve the diversion accuracy of the dual-cylinder system during the start-stop stage, while reducing the impact on the overflow valve during the start-stop stage and extending the life of the overflow valve.

[0005] Technical solution: A crane power control system described in the present invention includes a reversing valve, the pressure oil outlet of the reversing valve is connected to a first pipeline and a second pipeline through a dividing and collecting valve, the first pipeline and the second pipeline are respectively connected to the working oil supply chambers of two oil cylinders, a two-way overflow valve is arranged between the first pipeline and the second pipeline, a one-way valve is arranged at the inlet of the two-way overflow valve, and the one-way valve controls the pressure oil to enter the two-way overflow valve from the reversing one-way.

[0006] Preferably, the two-way overflow valve comprises a first overflow valve and a second overflow valve, the pressure oil of the first pipeline enters the second pipeline through the second overflow valve, and the pressure oil of the second pipeline enters the first pipeline through the first overflow valve.

[0007] Preferably, the two-way relief valve includes a first relief valve and a second relief valve connected in series, and the one-way valve includes a first one-way valve and a second one-way valve. The first relief valve and the second relief valve are in opposite directions. The first one-way valve is connected in parallel at both ends of the first relief valve, and the first one-way valve controls the one-way flow of oil into the second relief valve; the second one-way valve is connected in parallel at both ends of the second relief valve, and the second one-way valve controls the one-way entry of oil into the first relief valve.

[0008] Preferably, the oil return port inlet of the reversing valve is connected to a third pipeline and a fourth pipeline, the third pipeline and the fourth pipeline are respectively connected to the operating oil return chambers of the two oil cylinders, and the third pipeline and the fourth pipeline are respectively provided with a first hydraulic lock.

[0009] Preferably, the first hydraulic lock located in the third pipeline is unlocked by the pressure oil of the first pipeline, and the first hydraulic lock located in the fourth pipeline is unlocked by the pressure oil of the second pipeline.

[0010] Preferably, the first hydraulic lock comprises a balancing valve, a valve core control chamber of the balancing valve located in the third pipeline is connected to the first pipeline, and a valve core control chamber of the balancing valve located in the fourth pipeline is connected to the second pipeline.

[0011] Preferably, the first pipeline and the second pipeline are respectively provided with a second hydraulic lock.

[0012] Preferably, the control chamber of the second hydraulic lock located in the first pipeline is connected to the third pipeline and is unlocked by the pressure oil of the third pipeline, and the control chamber of the second hydraulic lock located in the second pipeline is connected to the fourth pipeline and is unlocked by the pressure oil of the fourth pipeline.

[0013] Preferably, a main oil return pipeline is provided at the oil return port outlet of the reversing valve, and a third overflow valve is provided between the pressure oil outlet of the reversing valve and the main oil return pipeline.

[0014] Preferably, a fourth overflow valve is provided between the oil return port inlet of the reversing valve and the main oil return pipeline.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following advantages: 1. It reduces the impact on the overflow valve during the start-stop stage of the dual-cylinder system and extends the life of the overflow valve; 2. It improves the synchronization accuracy: when asynchronism occurs, after the cylinder on one side is in place, the cylinder on the other side can move quickly into place. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the crane power control system of the present invention;

[0017] Figure 2 for Figure 1 Enlarged view of the structure in the middle. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0019] like Figure 1 , Figure 2The crane power system of the present invention is mainly composed of a cylinder 4, a cylinder 5, and a power unit 1 for providing pressure oil to the cylinders 4 and 5. The control system includes a reversing valve 2. The oil inlet of the reversing valve 2 is connected to the P port of the power unit 1 through a main oil inlet pipeline, and the oil return port is connected to the T port of the power unit through a main oil return pipeline. The pressure oil outlet A of the reversing valve 2 is connected to the first pipeline 12 and the second pipeline 13 through a dividing and collecting valve 31. The first pipeline 12 and the second pipeline 13 are respectively connected to the working oil supply chambers (rodless chamber / large chamber) of the two cylinders 4 and 5. A two-way overflow valve is provided between the first pipeline 12 and the second pipeline 13. When a pressure difference occurs between the first pipeline 12 or the second pipeline 13, and the pressure difference exceeds the overflow pressure of the two-way overflow valve, the side with higher pressure inside the first pipeline 12 or the second pipeline 13 guides the pressure oil to the side with lower pressure through the two-way overflow valve. A one-way valve is provided at the inlet end of the two-way relief valve, and the one-way valve controls the pressure oil to enter the two-way relief valve from the reversing valve in one direction. Specifically, the two-way relief valve includes a first relief valve 4 and a second relief valve 5. The pressure oil in the first pipeline 12 enters the second pipeline 13 through the second relief valve 5, and the pressure oil in the second pipeline 13 enters the first pipeline 12 through the first relief valve 4.

[0020] The first relief valve 34 and the second relief valve 35 can be connected in series or in parallel and connected between the first pipeline 12 and the second pipeline 13. Taking the series connection as an example, Figure 1 The connection directions of the first relief valve 34 and the second relief valve 35 are opposite. The one-way valve includes a first one-way valve 32 and a second one-way valve 33. The first one-way valve 32 is connected in parallel at both ends of the first relief valve 34 to control the pressure oil to flow into the second relief valve 35 in one direction. The first one-way valve 32 matches the opening pressure of the second relief valve 35. Similarly, the second one-way valve 33 is connected in parallel at both ends of the second relief valve 35 to control the pressure oil to enter the first relief valve 34 in one direction.

[0021] like Figure 1The control system further includes a third pipeline 11 and a fourth pipeline 14, which are respectively connected to the working oil return chambers (rod chambers / small chambers) of the two oil cylinders, and the inlet of the oil return port B of the reversing valve 2 is connected to the third pipeline 11 and the fourth pipeline 14. The third pipeline 11 and the fourth pipeline 14 are respectively provided with hydraulic locks 8 and 9, wherein the hydraulic lock located in the third pipeline 11 is unlocked by the pressure oil of the first pipeline 12, and the hydraulic lock located in the fourth pipeline 14 is unlocked by the pressure oil of the second pipeline 13. Specifically, the balance located in the third pipeline 11 Taking the hydraulic lock 8 as an example, the hydraulic lock 8 includes a balancing valve, which has a first one-way position and a second one-way position. The first one-way position controls the one-way flow of the third pipeline 11 to the oil cylinder 4 (V2 to C2 in the figure), and the second one-way position controls the one-way flow of the oil cylinder 4 to the third pipeline 11 (C2 to V2 in the figure). The valve core control chamber of the second one-way position is connected to the first pipeline 12, and the second one-way position is unlocked by the pressure oil of the first pipeline 12. Similarly, the control chamber of the valve core of the balancing valve of the hydraulic lock located in the fourth pipeline 14 is connected to the second pipeline 13, and is unlocked by the pressure oil of the second pipeline 13. Like the hydraulic locks 8 and 9, hydraulic locks can also be respectively arranged on the first pipeline 12 and the second pipeline 13. The control chamber of the hydraulic lock located in the first pipeline 12 is connected to the third pipeline 11, and is unlocked by the pressure oil of the third pipeline 11. The control chamber of the second hydraulic lock located in the second pipeline 13 is connected to the fourth pipeline 14, and is unlocked by the pressure oil of the fourth pipeline 14.

[0022] A main return oil pipeline is provided at the return oil port outlet of the reversing valve 2, a third overflow valve is provided between the pressure oil outlet of the reversing valve 2 and the main return oil pipeline, and a fourth overflow valve is provided between the return oil port inlet of the reversing valve 2 and the main return oil pipeline, so that excess pressure oil of the system returns to the power unit.

[0023] The working principle of this control system is as follows: when the V port of valve 3 is connected to oil, the hydraulic oil passes through the diverter and collector valve 31, and the oil is evenly distributed to the oil outlets V1 and V2. When the load difference between the V1 port and the V2 port is large, the oil distribution amount of the V1 port and the V2 port will be different, resulting in an asynchronous phenomenon. For example, when the pressure of V1 is greater than the pressure of the V2 port, since the one-way valves 32, 33 and the overflow valves 34, 35 are set between the first pipeline 12 and the second pipeline 13, the high-pressure V1 port oil will pass through the one-way valve 32, flow to the overflow valve 35 on the right, and reach the V2 port. The pressure difference between the V1 port and the V2 port is reduced, so that the diverting accuracy of the diverter and collector valve 31 is increased, thereby improving the diverting accuracy of the system.

[0024] When the load difference between port V1 and port V2 is large, and the stroke of the cylinders on both sides is long, the cylinders on both sides will be out of sync. For example, when the cylinder connected to port V1 is in place first, port V1 will no longer have outflow. Due to the characteristics of the flow divider and collector valve 31, the flow of port V2 is also very small or even nonexistent at this time. Then the speed of the cylinder connected to port V2 is very slow or even nonexistent. The flow of port V1 can pass through the one-way valve 32, flow to the overflow valve 35 on the right, and reach port V2, so that port V2 can still maintain a large flow output, and the cylinder on the other side can also be in place quickly.

Claims

1. A crane power control system, characterized in that: The invention comprises a reversing valve (2), wherein the pressure oil outlet of the reversing valve (2) is connected to a first pipeline (12) and a second pipeline (13) via a flow dividing and collecting valve (31), the first pipeline (12) and the second pipeline (13) are respectively connected to the working oil supply chambers of two oil cylinders, a two-way overflow valve is arranged between the first pipeline (12) and the second pipeline (13), and a one-way valve is arranged at the inlet of the two-way overflow valve, and the one-way valve controls the pressure oil to enter the two-way overflow valve from the reversing valve (2) in one direction.

2. The crane power control system according to claim 1, characterized in that: The two-way overflow valve comprises a first overflow valve (34) and a second overflow valve (35); the pressure oil in the first pipeline (12) enters the second pipeline (13) through the second overflow valve (35); and the pressure oil in the second pipeline (13) enters the first pipeline (12) through the first overflow valve (4).

3. The crane power control system according to claim 1 or 2, characterized in that: The two-way overflow valve comprises a first overflow valve (34) and a second overflow valve (35) connected in series, and the one-way valve comprises a first one-way valve (32) and a second one-way valve (33). The first overflow valve (34) and the second overflow valve (35) are in opposite directions. The first one-way valve (32) is connected in parallel at both ends of the first overflow valve (4), and the first one-way valve (32) controls the oil to flow into the second overflow valve (35) in one direction; the second one-way valve (33) is connected in parallel at both ends of the second overflow valve (35), and the second one-way valve (33) controls the oil to enter the first overflow valve (4) in one direction.

4. The crane power control system according to claim 1, characterized in that: The oil return port inlet of the reversing valve (2) is connected to a third pipeline (11) and a fourth pipeline (14); the third pipeline (11) and the fourth pipeline (14) are respectively connected to the operating oil return chambers of the two oil cylinders; and the third pipeline (11) and the fourth pipeline (14) are respectively provided with a first hydraulic lock.

5. The crane power control system according to claim 1, characterized in that: The first hydraulic lock located in the third pipeline (11) is unlocked by the pressure oil in the first pipeline (12), and the first hydraulic lock located in the fourth pipeline (14) is unlocked by the pressure oil in the second pipeline (13).

6. The crane power control system according to claim 1, characterized in that: The first hydraulic lock comprises a balancing valve, wherein the valve core control chamber of the balancing valve located in the third pipeline (11) is connected to the first pipeline (12), and the valve core control chamber of the balancing valve located in the fourth pipeline (14) is connected to the second pipeline (13).

7. The crane power control system according to claim 1, characterized in that: The first pipeline (12) and the second pipeline (13) are respectively provided with a second hydraulic lock.

8. The crane power control system according to claim 1, characterized in that: The control chamber of the second hydraulic lock located in the first pipeline (12) is connected to the third pipeline (11) and is unlocked by the pressure oil of the third pipeline (11); the control chamber of the second hydraulic lock located in the second pipeline (13) is connected to the fourth pipeline (14) and is unlocked by the pressure oil of the fourth pipeline (14).

9. The crane power control system according to claim 1, characterized in that: The oil return port outlet of the reversing valve (2) is provided with a main oil return pipeline, and a third overflow valve is provided between the pressure oil outlet of the reversing valve (2) and the main oil return pipeline.

10. The crane power control system according to claim 9, characterized in that: A fourth overflow valve is provided between the oil return port inlet of the reversing valve (2) and the main oil return pipeline.

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