Active sway reduction system and control method for container reach crane spreader

Abstract

The present invention discloses an active swing reduction system for a container front crane, comprising an oil source, an oil tank, a buffer oil cylinder, a first electric proportional throttle valve, a second electric proportional throttle valve and a pressure relief valve, and also comprising a first pressure sensor, a second pressure sensor and a third pressure sensor which are communicatively connected to a controller, wherein the first pressure sensor is used to detect the rodless chamber pressure of the buffer oil cylinder, the second pressure sensor is used to detect the pressure at the oil outlet of the pressure relief valve, and the third pressure sensor is used to detect the rod chamber pressure of the buffer oil cylinder, and the controller controls the opening of the first electric proportional throttle valve and the second electric proportional throttle valve according to the pressure detection result. Active adjustment is achieved when the swing amplitude is too large, the swing amplitude and the swing frequency are reduced, and the safety during operation and transportation is improved. The present invention also discloses a control method for applying the above-mentioned active swing reduction system for a container front crane.

Description

Technical Field

[0001] The present invention relates to the field of reach stackers, and in particular to an active sway reduction system for a container reach stacker. In addition, the present invention also relates to a control method using the active sway reduction system for a container reach stacker. Background Art

[0002] Reach-lift container crane is also called reach-lift, which is a special equipment mainly used for container handling. The spreader is the working device of the reach-lift. Before handling, the spreader is aligned with the container, and then the container is locked to ensure that the container does not fall during the handling process. When the spreader arrives at the designated location, it is unlocked and the container is lowered.

[0003] In order to ensure that the container can be lifted smoothly during transportation, a buffer cylinder needs to be installed between the boom and the spreader of the reach crane. At the same time, a certain amount of damping is added to the oil inlet and return pipelines of the buffer cylinder so that it can buffer the swing of the spreader.

[0004] However, during the boom pitching process, the spreader needs to rely on gravity to swing by itself to keep the spreader horizontal. Since this process is a follow-up process, and there is damping in the oil inlet and return lines of the buffer cylinder, the spreader still needs a certain amount of time to return to the horizontal position after the boom stops moving, affecting the working efficiency. Similarly, after the boom is quickly extended and retracted, the spreader also needs a certain amount of time to return to the horizontal position. In the actual handling process, the vehicle's driving speed varies and the weight of the container is also uncertain. Therefore, it is very easy to cause the spreader to swing violently during rapid acceleration or deceleration, affecting driving safety. Since the oil inlet and return lines of traditional spreaders only have fixed damping holes to slow down the swing speed of the spreader, the swing reduction effect is poor and it is difficult to adapt to complex and changeable vehicle usage scenarios.

[0005] Therefore, how to provide an active sway reduction system for container reach loaders that can adjust the damping size is a technical problem that technical personnel in this field currently need to solve. Summary of the invention

[0006] The purpose of the present invention is to provide an active sway reduction system for a container reach stacker, which can automatically adjust the damping in the buffer oil circuit according to the swing speed of the spreader during container handling, so as to achieve controllable swing speed of the spreader and improve the safety of the handling process. Another purpose of the present invention is to provide a control method using the above-mentioned active sway reduction system for a container reach stacker.

[0007] In order to solve the above technical problems, the present invention provides an active sway reduction system for a container front crane sling, comprising an oil source, an oil tank, a buffer oil cylinder, a first electric proportional throttle valve, a second electric proportional throttle valve and a pressure reducing relief valve, wherein the two ends of the buffer oil cylinder are respectively connected to the boom and the sling, the oil source is connected to the oil inlet of the pressure reducing relief valve, the oil drain port of the pressure reducing relief valve is connected to the oil tank, the oil outlet of the pressure reducing relief valve is simultaneously connected to a working port of the first electric proportional throttle valve and a working port of the second electric proportional throttle valve, and the other working port of the first electric proportional throttle valve is connected to the The rod chamber of the buffer cylinder, the other working port of the second electric proportional throttle valve is connected to the rodless chamber of the buffer cylinder, and also includes a first pressure sensor, a second pressure sensor and a third pressure sensor which are communicatively connected to the controller, the first pressure sensor is used to detect the rodless chamber pressure of the buffer cylinder, the second pressure sensor is used to detect the pressure at the oil outlet of the pressure reducing relief valve, the third pressure sensor is used to detect the rod chamber pressure of the buffer cylinder, and the controller controls the opening of the first electric proportional throttle valve and the second electric proportional throttle valve according to the pressure detection result.

[0008] Preferably, it also includes a first one-way valve and a second one-way valve, the first one-way valve is connected in parallel with the first electric proportional throttle valve, the inlet of the first one-way valve is connected to the oil outlet of the pressure reducing relief valve, the outlet of the first one-way valve is connected to the rod chamber of the buffer cylinder, the second one-way valve is connected in parallel with the second electric proportional throttle valve, the inlet of the second one-way valve is connected to the oil outlet of the pressure reducing relief valve, and the outlet of the second one-way valve is connected to the rodless chamber of the buffer cylinder.

[0009] Preferably, it also includes a safety valve and two safety one-way valves, the rod chamber and the rodless chamber of the buffer cylinder are respectively connected to the inlets of the two safety one-way valves, and the outlets of the two safety one-way valves are connected to the oil tank through the safety valves.

[0010] Preferably, it comprises two buffer cylinders which are arranged in parallel and move synchronously, the rod chambers of the two buffer cylinders are connected to each other, and the rodless chambers of the two buffer cylinders are connected to each other.

[0011] Preferably, the detection port of the first pressure sensor is connected to the oil circuit between the two rodless cavities of the buffer cylinders, the detection port of the second pressure sensor is connected to the oil outlet of the pressure reducing relief valve, and the detection port of the third pressure sensor is connected to the oil circuit between the two rod cavities of the buffer cylinders.

[0012] The present invention provides a control method for an active sway reduction system for a container reach stacker, which is used to control any one of the above-mentioned active sway reduction systems for a container reach stacker, comprising the steps of:

[0013] Obtaining a first detection pressure at a rodless chamber of a buffer oil cylinder, a second detection pressure at an oil outlet of a pressure reducing relief valve, and a third detection pressure at a rod chamber of the buffer oil cylinder;

[0014] Comparing the first detection pressure with the third detection pressure, and determining the extension and retraction state of the buffer cylinder according to the comparison result;

[0015] If the first detection pressure is less than the third detection pressure, it is determined that the buffer cylinder is in an extended state, and a first pressure difference across the first electric proportional throttle valve is obtained, where the first pressure difference is a difference between the third detection pressure and the second detection pressure;

[0016] Comparing the first pressure difference with a first preset difference, if the first pressure difference is less than the first preset difference, not controlling the first electric proportional throttle valve, and if the first pressure difference is greater than or equal to the first preset difference, controlling the first electric proportional throttle valve to reduce the opening until the first pressure difference is less than the first preset difference;

[0017] If the first detection pressure is greater than the third detection pressure, it is determined that the buffer cylinder is in a retracted state, and a second pressure difference across the second electric proportional throttle valve is obtained, where the second pressure difference is a difference between the first detection pressure and the second detection pressure;

[0018] Compare the second pressure difference with the second preset difference. If the second pressure difference is less than the second preset difference, the second electric proportional throttle valve is not controlled. If the second pressure difference is greater than or equal to the second preset difference, the second electric proportional throttle valve is controlled to reduce the opening until the second pressure difference is less than the second preset difference.

[0019] Preferably, the controlling the first electric proportional throttle valve to reduce the opening and the controlling the second electric proportional throttle valve to reduce the opening include the steps of:

[0020] The controller adjusts the current intensity delivered to the first electric proportional throttle valve and the second electric proportional throttle valve.

[0021] Preferably, the method further comprises the steps of:

[0022] After the first pressure difference is less than the first preset difference for a preset time, and after the second pressure difference is less than the second preset difference for a preset time, the intensity of the delivered current gradually decreases to zero;

[0023] Preferably, when the current intensity supplied to the first electric proportional throttle valve and the second electric proportional throttle valve is adjusted to a maximum current value, the first electric proportional throttle valve and the second electric proportional throttle valve are both in an isolated state.

[0024] Preferably, the current intensity is calculated by a formula:

[0025] Q max -ΔQ=k·f(I)·ΔP m

[0026] Among them, Q max is the maximum flow rate through the first electric proportional throttle valve or the second electric proportional throttle valve at the maximum swing speed, ΔQ is a preset safety value, k is a flow coefficient, f(I) is a functional relationship between the opening area and the current value, ΔP is the first pressure difference or the second pressure difference, and m is a valve structural parameter and is used as an exponent of ΔP in the formula.

[0027] The present invention provides an active swing reduction system for a container front crane sling, comprising an oil source, an oil tank, a buffer oil cylinder, a first electric proportional throttle valve, a second electric proportional throttle valve and a pressure reducing relief valve, wherein two ends of the buffer oil cylinder are respectively connected to a boom and a sling, the oil source is connected to an oil inlet of the pressure reducing relief valve, an oil drain port of the pressure reducing relief valve is connected to the oil tank, an oil outlet of the pressure reducing relief valve is simultaneously connected to a working port of the first electric proportional throttle valve and a working port of the second electric proportional throttle valve, another working port of the first electric proportional throttle valve is connected to a rod cavity of the buffer oil cylinder, and another working port of the second electric proportional throttle valve is connected to a rodless cavity of the buffer oil cylinder, and further comprising a first pressure sensor, a second pressure sensor and a third pressure sensor which are communicatively connected to a controller, the first pressure sensor being used to detect the rodless cavity pressure of the buffer oil cylinder, the second pressure sensor being used to detect the pressure at the oil outlet of the pressure reducing relief valve, and the third pressure sensor being used to detect the rod cavity pressure of the buffer oil cylinder, and the controller controls the opening of the first electric proportional throttle valve and the second electric proportional throttle valve according to the pressure detection result.

[0028] When the reach stacker is moving containers, the spreader will swing back and forth. The pressure value of each node is obtained through each pressure sensor, and the pressure value is used to determine whether the spreader swings back and forth too fast. If it is too fast, the opening of the electric proportional throttle valve is adjusted, and then the damping size in the buffer oil circuit is adjusted. Active adjustment is achieved when the swing amplitude is too large, reducing the swing amplitude and frequency, and improving safety during operation and transportation.

[0029] The present invention also provides a control method for applying the above-mentioned active anti-sway system of the container front crane. Since the above-mentioned system has the above-mentioned technical effect, the above-mentioned control method should also have the same technical effect, which will not be introduced in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a hydraulic principle diagram of a specific embodiment of the active sway reduction system for container reach crane spreaders provided by the present invention;

[0031] FIG2 is a schematic structural diagram of a specific implementation of the active sway reduction system for container reach stacker provided by the present invention.

[0032] Among them, there are oil source 1, oil tank 2, buffer cylinder 3, first electric proportional throttle valve 4, second electric proportional throttle valve 5, pressure reducing relief valve 6, first pressure sensor 7, second pressure sensor 8, third pressure sensor 9, first check valve 10, second check valve 11, safety valve 12, safety check valve 13, boom 14, and hoist 15. DETAILED DESCRIPTION

[0033] The core of the present invention is to provide an active sway reduction system for a container reach stacker, which can automatically adjust the damping in the buffer oil circuit according to the swing speed of the spreader during container handling, so as to control the swing speed of the spreader and improve the safety of the handling process. Another core of the present invention is to provide a control method for applying the above-mentioned active sway reduction system for a container reach stacker.

[0034] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0035] Please refer to Figures 1 and 2. Figure 1 is a hydraulic principle diagram of a specific implementation of the active swing reduction system for a container reach crane spreader provided by the present invention; Figure 2 is a structural schematic diagram of a specific implementation of the active swing reduction system for a container reach crane spreader provided by the present invention.

[0036] A specific embodiment of the present invention provides an active sway reduction system for a container front crane sling, comprising an oil source 1, an oil tank 2, a buffer cylinder 3, a first electric proportional throttle valve 4, a second electric proportional throttle valve 5 and a pressure reducing relief valve 6. The oil source 1 provides high-pressure oil for the oil circuit, the oil tank 2 stores the hydraulic oil required by the system and receives the refluxed hydraulic oil, one end of the buffer cylinder 3 is connected to the boom 14, and the other end of the buffer cylinder 3 is connected to the sling 15. Among them, the oil source 1 is connected to the oil inlet of the pressure relief valve 6, the oil drain port of the pressure relief valve 6 is connected to the oil tank 2, and the oil outlet of the pressure relief valve 6 is simultaneously connected to the first working port of the first electric proportional throttle valve 4 and the first working port of the second electric proportional throttle valve 5. Furthermore, the second working port of the first electric proportional throttle valve 4 is connected to the rod chamber of the buffer cylinder 3, and the second working port of the second electric proportional throttle valve 5 is connected to the rodless chamber of the buffer cylinder 3, that is, the rod chamber of the buffer cylinder 3 is connected to the rodless chamber of the buffer cylinder 3 through the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5 connected in series in sequence, and the buffer cylinder 3 realizes the connection of the two end cavities through the two electric proportional throttle valves, and the oil outlet of the pressure relief valve 6 is connected to the oil path between the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5. Specifically, it includes two buffer cylinders 3 arranged in parallel and moving synchronously, the rod chambers of the two buffer cylinders 3 are connected to each other, and the rodless chambers of the two buffer cylinders 3 are connected to each other.

[0037] Furthermore, it also includes a controller and a first pressure sensor 7, a second pressure sensor 8 and a third pressure sensor 9. The three pressure sensors and the two electric proportional throttle valves are all connected to the controller in communication. Among them, the first pressure sensor 7 is used to detect the rodless chamber pressure of the buffer cylinder 3, the second pressure sensor 8 is used to detect the pressure at the oil outlet of the pressure reducing relief valve 6, and the third pressure sensor 9 is used to detect the rod chamber pressure of the buffer cylinder 3. The controller controls the opening of the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5 according to the pressure detection results.

[0038] Specifically, the oil inlet of the pressure reducing relief valve 6 is directly connected to the oil source 1, and the outlet pressure is set to a fixed value. When the outlet pressure is lower than the set value, the oil of the oil source 1 is reduced by the pressure reducing relief valve 6 to keep the outlet pressure at the set value. When the outlet pressure exceeds the outlet pressure set value, the outlet oil flows out through the oil drain port of the pressure reducing relief valve 6, so that the outlet pressure is reduced until it returns to the set value. One end of the first electric proportional throttle valve 4 is connected to the oil outlet of the pressure reducing relief valve 6, and the other end is connected to the rod cavity of the buffer oil cylinder 3. The size of its throttling area can be controlled by the size of the electrical signal to achieve damping adjustment. When the damping is maximum, the two ends of the first electric proportional throttle valve 4 are isolated.

[0039] One end of the second electric proportional throttle valve 5 is connected to the oil outlet of the pressure reducing relief valve 6, and the other end is connected to the rodless chamber of the buffer cylinder 3. The size of its throttling area can be controlled by the size of the electrical signal to achieve damping adjustment. When the damping is maximum, the two ends of the second electric proportional throttle valve 5 are isolated.

[0040] During the swinging process of the sling 15, the buffer cylinder 3 is in two states: extended and retracted. When the buffer cylinder 3 is extended outward, the oil in the rod chamber of the buffer cylinder 3 flows to the rodless chamber of the buffer cylinder 3 through the first electric proportional throttle valve 4. Since there is an area difference between the rod chamber and the rodless chamber of the buffer cylinder 3, the oil flowing out of the rod chamber of the buffer cylinder 3 cannot fill the rodless chamber. At this time, the insufficient oil is replenished by the oil source 1 after being reduced in pressure through the pressure reducing relief valve 6. The extension speed of the buffer cylinder 3 is determined by the flow rate flowing through the first electric proportional throttle valve 4, so the extension speed of the buffer cylinder 3 can be adjusted by adjusting the first electric proportional throttle valve 4. When the buffer cylinder 3 retracts inward, the oil in the rodless chamber of the buffer cylinder 3 flows to the rod chamber of the buffer cylinder 3 through the second electric proportional throttle valve 5. Since there is an area difference between the rod chamber and the rodless chamber of the buffer cylinder 3, the oil flowing out of the rodless chamber of the buffer cylinder 3 is more than the oil required by the rod chamber. At this time, the excess flow overflows through the pressure reducing relief valve 6 and flows back to the oil tank 2. The retraction speed of the buffer cylinder 3 is determined by the flow through the second electric proportional throttle valve 5. Therefore, the retraction speed of the buffer cylinder 3 can be adjusted by adjusting the second electric proportional throttle valve 5.

[0041] During the pitching process of the front crane, the hoist needs to rely on gravity to keep itself relatively horizontal. In order to make it return to the horizontal position faster, the damping should be reduced as much as possible. At this time, the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5 shall not be energized to keep their opening area at the maximum, thereby improving working efficiency.

[0042] The specific working process is as follows: when the front crane is carrying a container, a certain electric signal is given to the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5, and the sling 15 will swing forward and backward, and the hydraulic oil circulates in the rod chamber and the rodless chamber of the buffer oil cylinder 3. Of course, the flow difference caused by the area difference is adjusted by the pressure reducing relief valve 6. During the swinging process of the sling 15, if the sling 15 swings forward too fast, the electric signal of the first electric proportional throttle valve 4 is adjusted to reduce the opening area of ​​the first electric proportional throttle valve 4, and the speed of the oil in the rod chamber of the buffer oil cylinder 3 flowing to the rodless chamber of the buffer oil cylinder 3 through the first electric proportional throttle valve 4 is reduced, so that the forward swing speed of the sling 15 can be reduced. If the sling 15 swings backward too fast, the electric signal of the second electric proportional throttle valve 5 is adjusted to reduce the opening area of ​​the second electric proportional throttle valve 5, and the speed of the oil in the rodless chamber of the buffer oil cylinder 3 flowing to the rod chamber of the buffer oil cylinder 3 through the second electric proportional throttle valve 5 is reduced, so that the backward swing speed of the sling 15 can be reduced. Whether the swing speed of the sling 15 meets the requirements is determined based on the detection results of the three pressure sensors. The detection results are accurate and the response is faster.

[0043] When the reach loader is transporting containers, the spreader 15 will swing back and forth. The pressure value of each node is obtained through each pressure sensor, and the pressure value is used to determine whether the spreader swings back and forth too fast. If it is too fast, the opening of the electric proportional throttle valve is adjusted, and then the damping size in the buffer oil circuit is adjusted, thereby realizing active adjustment when the swing amplitude is too large. Compared with the traditional fixed damping method, the adjustable damping can adapt to complex and changeable vehicle usage scenarios, respond more quickly, improve the efficiency of the lifting yard, reduce the swing amplitude and frequency, and improve the safety during operation and transportation.

[0044] Preferably, it also includes a first one-way valve 10 and a second one-way valve 11. The first one-way valve 10 is connected in parallel with the first electric proportional throttle valve 4. The inlet of the first one-way valve 10 is connected to the oil outlet of the pressure reducing relief valve 6. The outlet of the first one-way valve 10 is connected to the rod chamber of the buffer cylinder 3. That is, in the oil circuit provided with the first one-way valve 10, only hydraulic oil is allowed to enter the rod chamber of the buffer cylinder 3, thereby ensuring smooth flow of oil from the oil outlet of the pressure reducing relief valve 6 to the rod chamber of the buffer cylinder 3, while prohibiting the buffer cylinder 3 from 3, the hydraulic oil in the rod chamber of the buffer cylinder 3 flows out, the second one-way valve 11 is connected in parallel with the second electric proportional throttle valve 5, the inlet of the second one-way valve 11 is connected to the oil outlet of the pressure reducing relief valve 6, and the outlet of the second one-way valve 11 is connected to the rodless chamber of the buffer cylinder 3, that is, in this oil circuit provided with the second one-way valve 11, only the hydraulic oil is allowed to enter the rodless chamber of the buffer cylinder 3, ensuring that the oil from the oil outlet of the pressure reducing relief valve 6 to the rodless chamber of the buffer cylinder 3 flows smoothly, while prohibiting the hydraulic oil in the rodless chamber of the buffer cylinder 3 from flowing out. The first one-way valve 10 and the second one-way valve 11 can ensure that the buffer cylinder 3 is always full of oil.

[0045] In order to improve safety, a safety valve 12 and two safety one-way valves 13 are also included. The rod chamber and the rodless chamber of the buffer oil cylinder 3 are respectively connected to the inlets of the two safety one-way valves 13, and the outlets of the two safety one-way valves 13 are connected to the oil tank 2 through the safety valves 12. If the pressure in the buffer oil cylinder 3 is too high during the tilting or swinging of the sling 15, the oil will flow back to the oil tank 2 through the two safety one-way valves 13 and the safety valve 12, which plays a protective role.

[0046] Specifically, the detection port of the first pressure sensor 7 is connected to the oil circuit between the rodless chambers of the two buffer oil cylinders 3, and the detected pressure of the rodless chamber of the buffer oil cylinder 3 is the pressure of the second electric proportional throttle valve 5 close to the buffer oil cylinder 3. The detection port of the third pressure sensor 9 is connected to the oil circuit between the rod chambers of the two buffer oil cylinders 3, and the detected pressure of the rod chamber of the buffer oil cylinder 3 is the pressure of the first electric proportional throttle valve 4 close to the buffer oil cylinder 3. The detection port of the second pressure sensor 8 is connected to the oil outlet of the pressure reducing relief valve 6, and the detected pressure of the oil outlet of the pressure reducing relief valve 6 is the pressure of the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5 away from the buffer oil cylinder 3, that is, the pressure between the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5. In the above manner, the pressure at both ends of the first electric proportional throttle valve 4 and the pressure at both ends of the second electric proportional throttle valve 5 can be obtained.

[0047] In the above specific embodiments, adjusting the number and grouping of each cylinder and adjusting the type and control method of each valve according to the situation are all within the protection scope of the present invention. The selection in the above embodiments is only a preferred solution, and other types can also be used.

[0048] A specific embodiment of the present invention provides a control method for an active sway reduction system for a container reach stacker, which is used to control the active sway reduction system for a container reach stacker provided in the above embodiment, comprising the steps of:

[0049] Obtain the first detection pressure P1 at the rodless chamber of the buffer cylinder 3, the second detection pressure P2 at the oil outlet of the pressure reducing relief valve 6 and the third detection pressure P3 at the rod chamber of the buffer cylinder 3. P1 and P2 are the pressures at both ends of the second electric proportional throttle valve 5, and P3 and P2 are the pressures at both ends of the first electric proportional throttle valve 4.

[0050] When the buffer cylinder 3 extends, the oil flows from the rod chamber of the buffer cylinder 3 to the rodless chamber. According to the characteristics of the oil flowing from high pressure to low pressure, P3>P2>P1 at this time. The extension speed of the buffer cylinder 3 is determined by the flow Q1 flowing through the first electric proportional throttle valve 4. Therefore, the extension speed can be controlled by controlling the size of Q1.

[0051] When the buffer cylinder 3 retracts, the oil flows from the rodless chamber of the buffer cylinder 3 to the rod chamber. According to the characteristics of oil flowing from high pressure to low pressure, P1>P2>P3 at this time. The extension speed of the buffer cylinder 3 is determined by the flow Q2 flowing through the second electric proportional throttle valve 5. Therefore, the retraction speed can be controlled by controlling the size of Q2. According to the relationship between the flow rate and the opening, the extension and retraction speeds can be controlled by adjusting the opening.

[0052] According to the above discussion, the first detection pressure and the third detection pressure are compared, and the extension and retraction state of the buffer cylinder 3 is determined according to the comparison result.

[0053] If the first detection pressure is less than the third detection pressure, that is, P3>P2>P1, it is determined that the buffer cylinder 3 is in the extended state. Further, the first pressure difference ΔP1 across the first electric proportional throttle valve 4 is obtained. The first pressure difference is the difference between the third detection pressure and the second detection pressure, that is, ΔP 1= P3-P2.

[0054] Compare the first pressure difference ΔP1 with the first preset difference ΔP 1max , if the first pressure difference is less than the first preset difference, that is, ΔP1<ΔP 1max , indicating that the swing speed is not large, allowing the hanger 15 to swing freely without control.

[0055] Compare the first pressure difference ΔP1 with the first preset difference ΔP 1max , if the first pressure difference ΔP1 is greater than or equal to the first preset difference ΔP 1max , that is, ΔP1≥ΔP 1max , indicating that the swing speed is too large, the first electric proportional throttle valve 4 is controlled to reduce the opening until the first pressure difference ΔP1 is less than the first preset difference ΔP 1max .

[0056] If the first detection pressure is greater than the third detection pressure, that is, P1>P2>P3, it is determined that the buffer cylinder 3 is in the retracted state. Further, the second pressure difference ΔP2 at both ends of the second electric proportional throttle valve 5 is obtained. The second pressure difference is the difference between the first detection pressure and the second detection pressure, that is, ΔP 2= P1-P2.

[0057] Compare the second pressure difference ΔP2 with the second preset difference ΔP 2max , if the second pressure difference is less than the second preset difference, that is, ΔP2<ΔP 2max , indicating that the swing speed is not large, allowing the hanger 15 to swing freely without control.

[0058] Compare the second pressure difference ΔP2 with the second preset difference ΔP 2max If the second pressure difference ΔP2 is greater than or equal to the second preset difference ΔP 2max , that is, ΔP2≥ΔP 2max , indicating that the swing speed is too large, the second electric proportional throttle valve 5 is controlled to reduce the opening until the first pressure difference ΔP2 is less than the first preset difference ΔP 2max .

[0059] Preferably, controlling the first electric proportional throttle valve 4 to reduce its opening and controlling the second electric proportional throttle valve 5 to reduce its opening can be carried out in a variety of ways, such as the controller adjusting the current intensity delivered to the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5. Of course, other signal types can also be used, all within the protection scope of the present invention.

[0060] In order to improve control stability, after the first pressure difference is less than the first preset difference for a preset time, and after the second pressure difference is less than the second preset difference for a preset time, the delivered current intensity gradually decreases to zero, that is, the throttling effect is maintained for a sufficient time to ensure the deceleration effect.

[0061] Furthermore, when the current intensity delivered to the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5 is adjusted to the maximum current value, the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5 are both in an isolated state, so that the two ends of the throttle valve are blocked, thereby preventing the sling 15 from swinging.

[0062] Based on the control methods provided in the above specific implementations, the current intensity is calculated by the formula:

[0063] Q max -ΔQ=k·f(I)·ΔP m

[0064] Among them, Q max is the maximum flow rate through the first electric proportional throttle valve 4 or the second electric proportional throttle valve 5 at the maximum swing speed, ΔQ is the preset safety value, k is the flow coefficient, f (I) is the functional relationship between the opening area and the current value, ΔP is the first pressure difference or the second pressure difference, m is the valve structure parameter, and is used as the exponent of ΔP in the formula.

[0065] The specific derivation process is: the control of the swing speed of the hanger 15 can be converted into the control of the size of Q1 and Q2. The flow formula flowing through the throttle hole can generally be expressed as:

[0066] Q = k·A·ΔP m

[0067] Among them, Q is the flow rate, k is the flow coefficient, A is the unthrottled area of ​​the throttle hole, which is equivalent to the opening of the throttle valve, ΔP is the pressure difference across the throttle valve, and m is the valve structure parameter, which is determined by the structure of the throttle hole and is used as an exponent of ΔP in the formula.

[0068] Assume that A1 is the unthrottled area of ​​the first electric proportional throttle valve 4, A2 is the unthrottled valve area of ​​the second electric proportional throttle valve 5, and the first pressure difference ΔP1 across the first electric proportional throttle valve 4 is the difference between the third detection pressure and the second detection pressure, that is, ΔP 1= P3-P2, the second pressure difference ΔP2 at both ends of the second electric proportional throttle valve 5, the second pressure difference is the difference between the first detection pressure and the second detection pressure, that is, ΔP 2= P1-P2.

[0069] Due to the existence of the throttle valve, the speed of the sling 15 is relatively stable when it swings. In addition, due to the existence of the pressure relief valve 6, the values ​​of ΔP1 and ΔP2 will not be very large during actual operation, and the fluctuations of Q1 and Q2 are also relatively stable. Therefore, the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5 are less affected by the hydraulic force. Therefore, the size of A1 and A2 can be regarded as being determined only by its control electrical signals I1 and I2. In the electric proportional throttle valve, A and I form a functional relationship, then

[0070] A = f(I)

[0071] Substituting into the above formula we get

[0072] Q = k·f(I)·ΔP m

[0073] In order to ensure effective swing reduction, a preset safety value ΔQ is set. In the actual operation process, the sling 15 is allowed to swing freely at a certain swing speed. Assume that at the maximum swing speed, the flow rate Q flowing through the electric proportional throttle valve is Q max , and we get the formula

[0074] Q max -ΔQ=k·f(I)·ΔP m

[0075] According to the difference in parameters between the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5, substituting into the above formula, we can get

[0076] A1= f1(I1)

[0077] A2 = f2 (I2)

[0078] It is concluded that

[0079] Q1 = k·f1(I1)·ΔP1 m1

[0080] Q2 = k·f2(I2)·ΔP2 m2

[0081] Finally, it is concluded

[0082] Q 1max -ΔQ1=k·f1(I1)·ΔP1 m1

[0083] Q 2max -ΔQ2=k·f2(I2)·ΔP2 m2

[0084] From the above analysis, it can be concluded that the swing speed can be controlled by controlling the control electrical signals of the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5. When the first electric proportional throttle valve 4 and the second electric proportional throttle valve 5 do not participate in the control, the magnitudes of A1 and A2 are fixed, so the swing speed is only related to the magnitudes of ΔP1 and ΔP2.

[0085] In the actual operation process, the sling 15 is allowed to swing freely at a certain swing speed. Assuming that at the maximum swing speed, the flow rate Q1 flowing through the first electric proportional throttle valve 4 is Q 1max , the first pressure difference across the first electric proportional throttle valve 4 is ΔP1=ΔP 1max , the flow rate Q2=Q flowing through the second electric proportional throttle valve 5 2max , the second pressure difference across the second electric proportional throttle valve 5 is ΔP2=ΔP 2max .

[0086] When P3>P2>P1, it can be determined that the buffer cylinder 3 is in the extended state;

[0087] If ΔP1<ΔP 1max This indicates that the swing speed is not large, and the sling 15 is allowed to swing freely without control, that is, I1=0.

[0088] If ΔP1≥ΔP 1max It indicates that the swing speed is too large, and I1 satisfies the following formula:

[0089] Q 1max -ΔQ1=k·f1(I1)·ΔP1 m1

[0090] Among them, ΔQ1 is a preset safety value, which is set independently according to needs to control the anti-swing strength. Through the above formula, the current obtained can make the flow rate passing through the first electric proportional throttle valve 4 less than the maximum flow rate Q at the maximum swing speed. 1max , to achieve deceleration buffer.

[0091] Until ΔP1<ΔP 1max , after a predetermined time, if the above relationship still holds, I1 is gradually reduced to 0, otherwise it remains at the value calculated by the formula.

[0092] When P1>P2>P3, it can be determined that the buffer cylinder 3 is in the retracted state;

[0093] If ΔP2<ΔP 2max This indicates that the swing speed is not large, and the sling 15 is allowed to swing freely without control, that is, I2=0.

[0094] If ΔP2 ≥ ΔP 2max It indicates that the swing speed is too large, and I2 satisfies the following formula:

[0095] Q 2max -ΔQ2=k·f2(I2)·ΔP2 m2

[0096] Among them, ΔQ2 is a preset safety value, which is set independently according to needs and plays a role in controlling the anti-swing strength. Through the above formula, the current obtained can make the flow rate passing through the second electric proportional throttle valve 5 less than the maximum flow rate Q at the maximum swing speed. 2max , to achieve deceleration buffer.

[0097] Until ΔP2<ΔP 2max , after a predetermined time, if the above relationship still holds, I2 is gradually reduced to 0, otherwise it remains at the value calculated by the formula.

[0098] The above is a detailed introduction to the active anti-sway system and control method for the container reach loader provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A control method for an active sway reduction system of a container reach stacker, used for controlling the active sway reduction system of a container reach stacker, characterized in that: The active sway reduction system for a container front crane comprises an oil source (1), an oil tank (2), a buffer oil cylinder (3), a first electric proportional throttle valve (4), a second electric proportional throttle valve (5) and a pressure relief valve (6); the two ends of the buffer oil cylinder (3) are respectively connected to a boom (14) and a crane (15); the oil source (1) is connected to an oil inlet of the pressure relief valve (6); the oil drain port of the pressure relief valve (6) is connected to the oil tank (2); the oil outlet of the pressure relief valve (6) is simultaneously connected to a working port of the first electric proportional throttle valve (4) and a working port of the second electric proportional throttle valve (5); the other working port of the first electric proportional throttle valve (4) is connected to the buffer oil cylinder (3); The rod chamber of the oil cylinder (3), the other working port of the second electric proportional throttle valve (5) is connected to the rodless chamber of the buffer oil cylinder (3), and also includes a first pressure sensor (7), a second pressure sensor (8) and a third pressure sensor (9) which are communicatively connected to the controller, the first pressure sensor (7) being used to detect the pressure of the rodless chamber of the buffer oil cylinder (3), the second pressure sensor (8) being used to detect the pressure at the oil outlet of the pressure reducing relief valve (6), and the third pressure sensor (9) being used to detect the pressure of the rod chamber of the buffer oil cylinder (3), and the controller controlling the opening of the first electric proportional throttle valve (4) and the second electric proportional throttle valve (5) according to the pressure detection result; Includes steps: Obtaining a first detection pressure at a rodless chamber of the buffer oil cylinder (3), a second detection pressure at an oil outlet of a pressure reducing relief valve (6), and a third detection pressure at a rod chamber of the buffer oil cylinder (3); Comparing the first detection pressure with the third detection pressure, and judging the extension and retraction state of the buffer oil cylinder (3) according to the comparison result; If the first detection pressure is less than the third detection pressure, it is determined that the buffer cylinder (3) is in an extended state, and a first pressure difference across the first electric proportional throttle valve (4) is obtained, the first pressure difference being the difference between the third detection pressure and the second detection pressure; comparing the first pressure difference with a first preset difference, if the first pressure difference is less than the first preset difference, not controlling the first electric proportional throttle valve (4), and if the first pressure difference is greater than or equal to the first preset difference, controlling the first electric proportional throttle valve (4) to reduce the opening until the first pressure difference is less than the first preset difference; If the first detection pressure is greater than the third detection pressure, it is determined that the buffer cylinder (3) is in a retracted state, and a second pressure difference across the second electric proportional throttle valve (5) is obtained, the second pressure difference being the difference between the first detection pressure and the second detection pressure; The second pressure difference is compared with a second preset difference. If the second pressure difference is less than the second preset difference, the second electric proportional throttle valve (5) is not controlled. If the second pressure difference is greater than or equal to the second preset difference, the second electric proportional throttle valve (5) is controlled to reduce its opening until the second pressure difference is less than the second preset difference.

2. The control method of the active sway reduction system of the container reach stacker according to claim 1 is characterized in that: The controlling the first electric proportional throttle valve (4) to reduce the opening degree and the controlling the second electric proportional throttle valve (5) to reduce the opening degree comprise the steps of: The controller adjusts the intensity of the current supplied to the first electric proportional throttle valve (4) and the second electric proportional throttle valve (5).

3. The control method of the active anti-sway system of the container reach crane according to claim 2 is characterized in that: Also includes the steps: After the first pressure difference is smaller than the first preset difference for a preset time, and after the second pressure difference is smaller than the second preset difference for a preset time, the intensity of the delivered current gradually decreases to zero.

4. The control method of the active anti-sway system of the container reach stacker according to claim 3 is characterized in that: When the current intensity supplied to the first electric proportional throttle valve (4) and the second electric proportional throttle valve (5) is adjusted to a maximum current value, the first electric proportional throttle valve (4) and the second electric proportional throttle valve (5) are both in an isolated state.

5. The control method of the active sway reduction system of the container reach stacker according to any one of claims 2 to 4, characterized in that: The current intensity is calculated by the formula: Q max -ΔQ=k·f(I)·ΔP m Among them, Q max is the maximum flow rate flowing through the first electric proportional throttle valve (4) or the second electric proportional throttle valve (5) at the maximum swing speed, ΔQ is a preset safety value, k is a flow coefficient, f(I) is a functional relationship between the opening area and the current value, ΔP is the first pressure difference or the second pressure difference, and m is a valve structural parameter and is used as an exponent of ΔP in the formula.

6. The control method of the active sway reduction system of the container reach crane according to claim 1, characterized in that: The invention also comprises a first one-way valve (10) and a second one-way valve (11), wherein the first one-way valve (10) is connected in parallel with the first electric proportional throttle valve (4), the inlet of the first one-way valve (10) is connected to the oil outlet of the pressure reducing relief valve (6), and the outlet of the first one-way valve (10) is connected to the rod chamber of the buffer cylinder (3), and the second one-way valve (11) is connected in parallel with the second electric proportional throttle valve (5), the inlet of the second one-way valve (11) is connected to the oil outlet of the pressure reducing relief valve (6), and the outlet of the second one-way valve (11) is connected to the rodless chamber of the buffer cylinder (3).

7. The control method of the active anti-sway system of the container reach stacker according to claim 6, characterized in that: It also includes a safety valve (12) and two safety one-way valves (13); the rod chamber and the rodless chamber of the buffer oil cylinder (3) are respectively connected to the inlets of the two safety one-way valves (13); and the outlets of the two safety one-way valves (13) are connected to the oil tank (2) through the safety valve (12).

8. The control method of the active sway reduction system of the container reach stacker according to claim 1, characterized in that: It comprises two buffer oil cylinders (3) arranged in parallel and moving synchronously, the rod chambers of the two buffer oil cylinders (3) being connected to each other, and the rodless chambers of the two buffer oil cylinders (3) being connected to each other.

9. The control method of the active sway reduction system of the container reach stacker according to claim 8, characterized in that: The detection port of the first pressure sensor (7) is connected to the oil circuit between the rodless chambers of the two buffer cylinders (3), the detection port of the second pressure sensor (8) is connected to the oil outlet of the pressure reducing relief valve (6), and the detection port of the third pressure sensor (9) is connected to the oil circuit between the rod chambers of the two buffer cylinders (3).

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