A regenerative adaptive balance valve device

Abstract

A regenerative self-adaptive balance valve device. It relates to the technical field of construction machinery, and particularly to a regenerative self-adaptive balance valve device for the boom luffing cylinder of a crane. A regenerative self-adaptive balance valve device is provided, which has a compact and reasonable structure and stable performance. When the crane boom is lowering, it can not only realize the regenerative utilization of the hydraulic oil flowing from the rodless cavity of the luffing cylinder back to the rod cavity, but also, when the gravity lowering torque is insufficient and the boom lowering speed is too slow, actively supply oil through the hydraulic system to achieve the powered lowering of the boom. It includes a raising oil circuit system and a lowering oil circuit system; the raising oil circuit system includes check valve D4 and check valve D5; the inlet of check valve D1 is connected to the fuel tank, and the outlet of check valve D1 is connected between check valve D2 and the luffing cylinder. The present invention eliminates the influence of the boom lowering and the pressure fluctuation in the small chamber of the luffing cylinder on the opening state of the moving balance valve core, and directly improves the motion smoothness of the boom lowering.

Description

Technical Field

[0001] The present invention relates to the technical field of construction machinery, and particularly to a regenerative adaptive balance valve device for a boom luffing oil cylinder of a crane. Background Art

[0002] Balance valve devices have been widely used in construction machinery such as cranes. It can prevent the vertical oil cylinder from falling at an excessive speed due to the self-weight of the vertically moving working components it drives, can achieve gravity balance and reliable motion locking for it, and has a pipe-breaking safety protection function. A crane is a gravity-operated construction machinery. When the boom falls, the load being lifted and the gravity of the boom participate in doing work.

[0003] Currently, there are two types of existing working modes for the boom falling of a crane: One is to supply oil to the small chamber of the boom luffing oil cylinder, use power drive, and the boom actively falls. Although the falling speed can be controlled, all the energy during the falling process of the heavy object is converted into heat, resulting in high energy consumption, high system oil temperature, and poor operating reliability of hydraulic components; The other is represented by the so-called "green valve" launched by Rexroth in 2010. It controls the opening of a motion balance valve by controlling the oil source and discharges oil from the large chamber of the crane luffing oil cylinder, and the boom realizes gravity falling under the action of its own weight. Since the control pressure required for the control port of the motion balance valve is very small, the energy consumption of the system during the boom falling is very small. However, in this boom falling working mode, when the elevation angle between the boom and the ground is large, the load is small, and the gravity moment during falling is small, the falling speed of the boom is very slow and uncontrollable.

[0004] Problems of the prior art also include that for construction machinery such as truck-mounted cranes, many do not have an independent hydraulic control oil source like a professional crane hydraulic system. When applying the boom self-weight falling technology, in the common balance valve installation method, the control port of the motion balance valve will be connected to the oil circuit of the rod chamber of the luffing oil cylinder. When the boom with a long arm or a heavy load falls, the pressure fluctuation in the rod chamber of the luffing oil cylinder will directly cause the opening of the motion balance valve core to jump violently, resulting in severe jitter during the boom falling process. At the same time, under the existing gravity falling condition, it is easy for the upper chamber of the luffing oil cylinder to suck air, and all the hydraulic oil in the lower chamber of the luffing oil cylinder flows through the multi-way valve core, causing excessive control force on the relevant multi-way valve core. And it also causes a certain amount of additional system heating. Summary of the Invention

[0005] In view of the above problems, the present invention provides a regenerative adaptive balance valve device that is compact and reasonable in structure, stable in performance. When the crane boom falls, it can not only realize the recycling of the hydraulic oil flowing back from the rodless chamber of the luffing oil cylinder to the rod chamber, but also actively supply oil through the hydraulic system to achieve the power falling of the boom when the gravity falling moment is insufficient and the boom falling speed is too slow.

[0006] The technical solution of the present invention is as follows: It includes a lifting oil circuit system and a lowering oil circuit system;

[0007] The lifting oil circuit system includes check valve D4 and check valve D5;

[0008] The inlet of check valve D4 is connected to an oil pump through a multi-way valve, and the outlet of check valve D4 is connected to the large chamber Q1 of the luffing cylinder;

[0009] The inlet of check valve D5 is connected to the rod chamber Q2 of the luffing cylinder, and the outlet of check valve D5 is connected to a fuel tank through a multi-way valve;

[0010] The lowering oil circuit system includes a direct-acting sequence valve SX, a damper Z, a moving balance valve PH, and a check valve D3;

[0011] One end of the one-way sequence valve is connected to an oil pump through a multi-way valve, and the other end is connected to the rod chamber Q2 of the luffing cylinder;

[0012] The outlet of check valve D3 is connected to a fuel tank through a multi-way valve;

[0013] One end of the moving balance valve PH is connected to the inlet of check valve D3, and the other end is connected to the large chamber Q1 of the luffing cylinder;

[0014] The control oil port 5 of the moving balance valve PH is connected to the inlet of the direct-acting sequence valve SX through the damper Z.

[0015] The lowering oil circuit system further includes a check valve D2;

[0016] The inlet of check valve D2 is connected between check valve D3 and the moving balance valve PH, and the outlet of the check valve is connected to the rod chamber Q2 of the luffing cylinder.

[0017] The lowering oil circuit system further includes a check valve D1;

[0018] The inlet of check valve D1 is connected to a fuel tank, and the outlet of check valve D1 is connected between check valve D2 and the luffing cylinder.

[0019] The lowering oil circuit system further includes a safety valve AQ;

[0020] One end of the safety valve AQ is connected between the rodless chamber of the luffing cylinder and the moving balance valve PH, and the other end is connected to the inlet of check valve D1 and directly communicates with the fuel tank.

[0021] The present invention relates to a flow regeneration balance valve device for a crane luffing oil cylinder, which can achieve power lowering and gravity lowering, and adaptively switch between the two lowering modes. The regenerative adaptive balance valve device mainly includes: a moving balance valve PH, a direct-acting sequence valve SX, a safety valve AQ, a damper Z, and five one-way valves D1 to D5; the V2, V1, and T oil ports are respectively the balance valve oil inlet for supplying oil to the large chamber and small chamber of the oil cylinder and the oil return port communicating with the oil tank; the C2 and C1 oil ports are the oil outlets of the balance valve directly connected to the large and small chambers of the oil cylinder. Through the application of the device in this case to a luffing oil cylinder such as a crane boom, when the hydraulic oil in the large chamber of the crane luffing oil cylinder returns during lowering, part of the hydraulic oil can fully flow back to the small chamber of the luffing oil cylinder for recycling, avoiding the air suction phenomenon in the upper chamber of the luffing oil cylinder during lowering, and also reducing the problems of excessive flow rate borne by the multi-way valve core and large spool control hydraulic force during boom lowering; at the same time, when the gravity lowering torque of the boom is insufficient, power supply for active lowering, and when the gravity lowering torque of the crane boom is sufficient, the boom self-weight lowering, the two boom lowering working modes can be adaptively switched. It can fully avoid the technical problems of high energy consumption in the single power supply lowering mode of the crane boom and uncontrollable speed in the single boom self-weight lowering mode; on the boom lowering control oil circuit, a direct-acting sequence valve is used to separate the control ports of the moving balance valves of the small chamber and large chamber of the luffing oil cylinder, eliminating the influence of boom lowering and pressure fluctuations in the small chamber of the luffing oil cylinder on the opening state of the moving balance valve core, and directly improving the movement smoothness of boom lowering. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the present invention,

[0023] Figure 2 is a hydraulic schematic diagram of the application and implementation of the present invention on a crane,

[0024] Figure 3 is a schematic diagram of the state of boom power lowering,

[0025] Figure 4 is a schematic diagram of the pressure difference curve generated on the direct-acting balance valve when the multi-way valve supplies oil to the rod chamber of the boom luffing oil cylinder. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention is as Figures 1-4 shown, and includes a hoisting oil circuit system and a lowering oil circuit system;

[0027] The hoisting oil circuit system includes a one-way valve D4 and a one-way valve D5;

[0028] The inlet of the one-way valve D4 is connected to an oil pump through a multi-way valve (the model of the multi-way valve in this case is PVG32 - 5PVEA), and the outlet of the one-way valve D4 is connected to the large chamber Q1 of the luffing oil cylinder;

[0029] The inlet of the one-way valve D5 is connected to the rod chamber Q2 of the luffing cylinder, and the outlet of the one-way valve D5 is connected to the fuel tank through the multi-way valve;

[0030] As Figure 1 , Figure 2 shown, when the crane boom luffing cylinder performs a lifting operation, the multi-way valve directly supplies oil to the large chamber Q1 of the luffing cylinder YG through the oil inlet V2, one-way valve D4 and oil port C2 in the regenerative adaptive balance valve device; at this time, the hydraulic oil in the rod chamber Q2 of the luffing cylinder YG flows back to the fuel tank through the oil port C1, one-way valve D5, and oil port V1 and through the multi-way valve. Driven by the luffing cylinder YG, the crane boom performs a lifting and luffing movement.

[0031] The lowering luffing oil circuit system includes a direct-acting sequence valve SX, a damper Z, a moving balance valve PH, and a one-way valve D3;

[0032] One end of the direct-acting sequence valve SX is connected to the oil pump through the multi-way valve, and the other end is connected to the rod chamber Q2 of the luffing cylinder;

[0033] The outlet of the one-way valve D3 is connected to the fuel tank through the multi-way valve;

[0034] One end of the moving balance valve PH is connected to the inlet of the one-way valve D3, and the other end is connected to the large chamber Q1 of the luffing cylinder;

[0035] The control oil port 5 of the moving balance valve PH is connected to the inlet of the direct-acting sequence valve SX through the damper Z.

[0036] The direct-acting sequence valve SX adopted in this case has a pressure difference curve at both ends of the valve generated by the flow rate passing through it as Figure 4 shown (in the figure, the horizontal axis represents: the flow rate Q (L / min) of the valve, the vertical axis represents: the corresponding pressure difference P (bar) at both ends of the valve port, and the curve represents: the curve of the corresponding pressure difference P at both ends of the valve port under different flow rates Q). When the boom luffing cylinder falls due to gravity and the pressure in its upper chamber appears low, at the position of the control oil port 5 of the moving balance valve core PH, there can be sufficient pressure (0 - 15 bar) to completely control the opening of the balance valve core, and the size of its opening can change with the size of the opening of the multi-way valve. Therefore, even when the boom falls due to gravity, the falling speed of the boom can be well controlled by the opening of the multi-way valve handle.

[0037] As Figure 2 , Figure 3 shown, in the figure, G is the weight of the suspended load, GG is the self-weight of the boom, L is the length of the boom, OG is the fixed hinge point of the luffing cylinder, OB is the fixed hinge point of the boom, and OZ is the connecting hinge point of the luffing cylinder and the boom. When the crane boom needs to perform a lowering operation, such as the angle θ between the boom and the ground, that is, the boom elevation angle as shown in the appendixFigure 3 As shown, it is very large, and the suspended load is light or unloaded. The combined gravity moment of the boom and the suspended load for the crane boom to lower its amplitude is very small. At this time, if only relying on the gravity of the boom to lower its amplitude, its speed will be very slow or it will be difficult to lower the amplitude at all.

[0038] In this situation, the hydraulic system supplies oil to the rod chamber Q2 of the luffing cylinder YG through the multi-way valve, oil port V1, direct-acting sequence valve SX, and oil port C1. The supplied hydraulic oil flows through the direct-acting sequence valve SX, generating a small but stable pressure difference (0 - 15 bar). Through the damper Z, it enters the control oil port 5 of the moving balance valve PH. Since PH is a moving balance valve, this small pressure difference is sufficient to control and fully open the balance valve core opening of the moving balance valve PH. At the same time, the hydraulic oil in the rodless chamber Q2 of the luffing cylinder YG returns to the hydraulic oil tank through oil port C2, the valve core opening of the moving balance valve PH, check valve D3, oil port V2, and the multi-way valve core.

[0039] The amplitude-lowering oil circuit system further includes a check valve D2;

[0040] The inlet of the check valve D2 is connected between the check valve D3 and the moving balance valve PH, and the outlet of the check valve is communicated with the rod chamber Q2 of the luffing cylinder. The crane boom makes a power amplitude-lowering movement under the action of the pressure oil in the rod chamber Q2 of the luffing cylinder. During the power amplitude-lowering process, since the pressure in the rod chamber Q2 must be greater than the pressure in the large chamber Q1, the check valve D2 is in a closed state.

[0041] The amplitude-lowering oil circuit system further includes a check valve D1;

[0042] The inlet of the check valve D1 is communicated with the oil tank, and the outlet of the check valve D1 is connected between the check valve D2 and the luffing cylinder. The regenerative adaptive balance valve device is also provided with a check valve D1 and an oil tank return pipe. The purpose is to provide an oil suction channel for the rod chamber Q2 of the luffing cylinder YG in case of a failure of the check valve D2 or other failures.

[0043] As attached Figure 3, when the crane boom is in the power lowering amplitude state, the elevation angle θ between the boom and the ground decreases from large to small, and the gravity lowering moment of the boom will increase from small to large. When the elevation angle θ decreases to a certain range, the gravity lowering of the boom will dominate the lowering process of the boom. At this time, the hydraulic system still supplies oil to the rod chamber Q2 of the luffing cylinder YG through the multi-way valve, oil port V1, one-way sequence valve SX and oil port C1. On the one hand, the hydraulic oil supplied to the rod chamber Q2 of the luffing cylinder YG flows through the direct-acting sequence valve SX, and there will still be a small pressure difference (0 - 15 bar) at both ends of the inlet and outlet of the direct-acting sequence valve. Through the damper Z, it enters the control oil port 5 of the moving balance valve PH, which can completely control the opening of the PH balance valve core. On the other hand, since a direct-acting sequence valve SX is isolated in the oil circuit between the rod chamber Q2 of the luffing cylinder YG and the control oil port 5 of the moving balance valve PH, the pressure fluctuation caused by the gravity lowering of the boom in the rod chamber Q2 of the luffing cylinder YG will no longer affect the control pressure at the control oil port 5 of the moving balance valve PH. The moving balance valve PH works stably and the boom lowering movement is smooth. However, when the boom is lowering under the action of the gravity moment, the oil supplied by the system to the rod chamber Q2 of the luffing cylinder YG will not be sufficient to reach the required oil supply for the gravity lowering speed, and a negative pressure phenomenon will occur in the rod chamber Q2 of the luffing cylinder YG, and the check valve D2 will open to suck oil. A large amount of hydraulic oil in the large chamber Q1 of the luffing cylinder YG that needs to return to the fuel tank will enter the oil port 3 of the moving balance valve PH through the moving balance valve PH. A part of the hydraulic oil will directly flow back to the rod chamber Q2 of the luffing cylinder YG through the check valve D2 opened by the negative pressure for recycling. Only the other excess part of the hydraulic oil flows back to the hydraulic fuel tank through the check valve D3, oil port V2 and the multi-way valve core. Objectively, this reduces the instantaneous flow rate of the hydraulic oil of the multi-way valve core, reduces the risk of excessive hydraulic force generated by the large flow rate of the multi-way valve core, and makes it more difficult to control the multi-way valve.

[0044] The lowering amplitude oil circuit system further includes a safety valve AQ;

[0045] One end of the safety valve AQ is connected between the luffing cylinder and the moving balance valve PH, and the other end is connected to the inlet of the check valve D1 and directly communicates with the fuel tank.

[0046] The safety valve AQ in the regenerative adaptive balance valve device is set because the moving balance valve PH is not an ordinary pressure type balance valve, and it is impossible to open the balance valve PH through the high pressure at its oil port 4. To avoid the large chamber Q1 of the luffing cylinder from having ultra-high pressure due to excessive boom load, the safety valve AQ is specially set to protect the boom and the luffing cylinder YG.

[0047] The control pressure range of the moving balance valve core PH of the balance valve device of the present invention is: 1.6~13 bar. Therefore, when the boom oil supply power drops, the system pressure can be set very low, generally set to 30~40 bar. In this way, even when the boom oil supply power drops, since the pressure of the entire hydraulic system is very low, the energy consumed is also very small.

Claims

1. A regenerative adaptive balance valve device, characterized in that, It includes a lifting oil circuit system and a lowering oil circuit system; The lifting oil circuit system includes check valve D4 and check valve D5; The inlet of the check valve D4 is connected to the oil pump through a multi-way valve, and the outlet of the check valve D4 is connected to the large chamber Q1 of the boom cylinder; The inlet of the check valve D5 is connected to the rod chamber Q2 of the boom cylinder, and the outlet of the check valve D5 is connected to the fuel tank through a multi-way valve; The lowering oil circuit system includes a direct-acting sequence valve SX, a damper Z, a moving-type balance valve PH, and a check valve D3; One end of the direct-acting sequence valve is connected to the oil pump through a multi-way valve, and the other end is connected to the rod chamber Q2 of the boom cylinder; The outlet of the check valve D3 is connected to the fuel tank through a multi-way valve; One end of the moving-type balance valve PH is connected to the inlet of the check valve D2, and the other end is connected to the large chamber Q1 of the boom cylinder; The control oil port (5) of the moving-type balance valve PH is connected to the inlet of the direct-acting sequence valve SX through the damper Z; Among them, during the power lowering process, A large amount of hydraulic oil in the large chamber Q1 of the boom cylinder that needs to return to the fuel tank enters the oil port of the moving-type balance valve PH through the moving-type balance valve PH. A part of the hydraulic oil will directly flow back to the rod chamber Q2 of the boom cylinder YG through the check valve D2 opened by negative pressure for recycling. The other redundant part of the hydraulic oil flows back to the hydraulic fuel tank through the check valve D3, the oil port V2, and the multi-way valve spool, reducing the instantaneous flow rate of the hydraulic oil in the multi-way valve spool, reducing the risk of excessive hydraulic force generated by the large flow rate in the multi-way valve spool and making it difficult to control the multi-way valve, and realizing the recycling of the oil fluid.

2. The regenerative self-adaptive balance valve device according to claim 1, characterized in that, The lowering oil circuit system further includes a check valve D2; The inlet of the check valve D2 is connected between the check valve D3 and the moving-type balance valve PH, and the outlet of the check valve is connected to the rod chamber Q2 of the boom cylinder.

3. The regenerative adaptive balance valve device according to claim 1, characterized in that The lowering oil circuit system further includes a check valve D1; The inlet of the check valve D1 is connected to the fuel tank, and the outlet of the check valve D1 is connected between the check valve D2 and the rod chamber Q2 of the boom cylinder.

4. A regenerative adaptive balance valve device according to claim 1, wherein The lowering oil circuit system further includes a safety valve AQ; One end of the safety valve AQ is connected between the boom cylinder and the moving-type balance valve PH, and the other end is connected to the inlet of the check valve D1 and directly leads to the fuel tank.

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