Lifting appliance control hydraulic circuit, reach stacker hydraulic control system and reach stacker

Abstract

The invention discloses a lifting appliance control hydraulic circuit, a reach stacker hydraulic control system and a reach stacker, and belongs to the technical field of reach stackers. The lifting appliance control hydraulic loop comprises a leveling oil cylinder, a leveling valve group and an oil supply port P1; the leveling valve group comprises a first leveling valve, a second leveling valve and a reversing control valve; when the first leveling valve and the second leveling valve are switched on at the same time, the lifting appliance performs self-adaptive leveling under the action of gravity; the reversing control valve is provided with a first conduction mode and a second conduction mode; the first conduction mode and the second conduction mode are switched through the reversing control valve, and the inclination direction of the lifting appliance is switched. The lifting appliance can be leveled in a self-adaptive manner, the inclination direction of the lifting appliance is switched, and the lifting difficulty is reduced.

Description

Technical Field

[0001] The invention relates to a spreader control hydraulic circuit, a reach stacker hydraulic control system and a reach stacker, and belongs to the technical field of reach stackers. Background Art

[0002] With the vigorous development of the container industry, container reach stackers are increasingly widely used in container operations due to their flexibility, small footprint, high stacking layers, and suitability for cross-container operations. They are particularly suitable for loading and unloading containers at small and medium-sized ports, railway transfer stations, and highway transfer stations, and can also be used as auxiliary equipment at large container terminals.

[0003] The spreader of the reach stacker is adjusted according to the size of the container and can be rotated to pass through narrow passages. In order to facilitate the alignment of the container, the spreader can move left and right, and a leveling cylinder is installed on the spreader. The leveling cylinder gives the spreader a certain tilt angle, so that the operator can align the container smoothly. During the movement, the leveling cylinder also has a leveling effect on the swing of the spreader.

[0004] The control of the leveling cylinder in the prior art has the following disadvantages: the inclination angle α of the sling is not controlled, which affects the working efficiency. Figure 1 As shown in the figure, when the front crane is lifting, it can be seen from the movement trajectory of the spreader that as the boom amplitude angle β changes, the lever arm L of the leveling cylinder changes. Therefore, in order to maintain the tilt angle of the spreader, the thrust of the leveling cylinder must change accordingly. In the existing technical solution, since the pressure reducing valve is constant, the pressure input to the cylinder is also constant, and the thrust generated is constant. Therefore, as the boom amplitude angle β changes, the tilt angle α of the spreader will also change. If α changes to a very small value, it will interfere with the operator's box operation and affect the work efficiency. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a spreader control hydraulic circuit, a reach stacker hydraulic control system and a reach stacker, which can enable the spreader to perform adaptive leveling, control the forward and backward tilt of the spreader, and reduce the difficulty of lifting. To achieve the above purpose, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides a sling control hydraulic circuit, including a leveling cylinder, a leveling valve group, and an oil supply port P1; The leveling valve group includes a first leveling valve, a second leveling valve and a reversing control valve; The first leveling valve is used to connect the oil supply port P1 with the large chamber oil port of the leveling oil cylinder, and the second leveling valve is used to connect the oil supply port P1 with the small chamber oil port of the leveling oil cylinder; when the first leveling valve and the second leveling valve are turned on at the same time, the pressure of the large chamber of the leveling oil cylinder is equal to the pressure of the small chamber, the spreader is in a floating position, and the spreader is adaptively leveled under the action of gravity; The reversing control valve is provided with a first conduction mode and a second conduction mode; in the first conduction mode, the oil supply port P1 is connected with the large-chamber oil port of the leveling cylinder, and in the second conduction mode, the oil supply port P1 is connected with the small-chamber oil port of the leveling cylinder; the inclination direction of the sling is switched by switching the first conduction mode and the second conduction mode through the reversing control valve.

[0006] In combination with the first aspect, optionally, the spreader control hydraulic circuit further includes a return port T; The inlet of the first leveling valve is connected to the oil supply port P1, and the outlet is connected to the large chamber oil port of the leveling cylinder. When the electromagnet of the first leveling valve is energized, the oil supply port P1 is connected to the large chamber of the leveling cylinder, and the hydraulic oil flows from the large chamber through the small chamber and enters the return port T; The inlet of the second leveling valve is connected to the oil supply port P1, and the outlet is connected to the small chamber oil port of the leveling cylinder. When the electromagnet of the second leveling valve is energized, the oil supply port P1 is connected to the small chamber of the leveling cylinder, and the hydraulic oil flows from the small chamber through the large chamber and then enters the return port T; The electromagnet of the first leveling valve and the electromagnet of the second leveling valve are energized at the same time, the large and small chambers of the leveling cylinder are connected, and the sling is adaptively leveled vertically downward under the action of gravity.

[0007] In combination with the first aspect, optionally, the spreader control hydraulic circuit further includes a return port T, the reversing control valve includes a first electromagnet and a second electromagnet, the spreader tilting direction includes a first direction and a second direction, and the first direction and the second direction are opposite directions; When the first electromagnet is energized, it is in the first conduction mode, the oil supply port P1 is connected to the small chamber oil port of the leveling cylinder through the reversing control valve, the hydraulic oil flows from the small chamber of the leveling cylinder through the large chamber and then enters the return port T, the piston rod of the leveling cylinder extends, and the sling is tilted in the first direction; When the second electromagnet is energized, it is in the second conduction mode, the oil supply port P1 is connected to the large chamber oil port of the leveling cylinder through the reversing control valve, the hydraulic oil flows from the large chamber of the leveling cylinder through the small chamber and then enters the return port T, the piston rod of the leveling cylinder retracts, and the sling tilts in the second direction.

[0008] In combination with the first aspect, optionally, the spreader control hydraulic circuit further includes an oil drain port D and a relief pressure reducing valve; The inlet of the relief pressure reducing valve is connected to the oil supply port P1, the outlet of the relief pressure reducing valve is connected to the inlet of the first leveling valve and the inlet of the second leveling valve, and the overflow port of the relief pressure reducing valve is connected to the oil drain port D on the valve body of the leveling valve.

[0009] In combination with the first aspect, optionally, the spreader control hydraulic circuit further comprises a damping regulating valve group for performing damping regulation on the spreader tilt, and the damping regulating valve group comprises a throttle hole with a large aperture and a throttle hole with a small aperture; The inlet of the damping regulating valve group is connected to the oil supply port P1, the hydraulic oil is connected to the large-cavity oil port of the leveling cylinder through the large-diameter throttle hole, and the hydraulic oil is connected to the small-cavity oil port of the leveling cylinder through the small-diameter throttle hole.

[0010] In a second aspect, the present invention provides a hydraulic control system for a reach stacker, comprising: a hydraulic pump and the spreader control hydraulic circuit described in the first aspect, wherein an outlet of the hydraulic pump is connected to an oil supply port P1 of the spreader control hydraulic circuit.

[0011] In combination with the second aspect, optionally, it further includes a boom working hydraulic circuit, the boom working hydraulic circuit includes a multi-way valve, an actuator cylinder and an oil supply port P2, the actuator cylinder includes a telescopic cylinder and a luffing cylinder; the oil supply port P2 is connected to the outlet of the hydraulic pump; When the multi-way valve connects the oil circuit between the oil supply port P2 and the telescopic cylinder, the piston rod of the telescopic cylinder extends or retracts to control the telescopic operation of the boom; When the multi-way valve connects the oil circuit between the oil supply port P2 and the luffing cylinder, the piston rod of the luffing cylinder extends or retracts to control the luffing operation of the boom.

[0012] In combination with the second aspect, optionally, the multi-way valve includes a telescopic cylinder solenoid valve, a telescopic cylinder pilot reversing valve, a luffing cylinder solenoid valve and a luffing cylinder pilot reversing valve, and the reach crane hydraulic control system further includes a pilot valve group; The inlet of the pilot valve group is connected to the outlet of the hydraulic pump, and the outlet of the pilot valve group is connected to the telescopic cylinder pilot reversing valve and the boom cylinder pilot reversing valve; the telescopic cylinder pilot reversing valve is used to push the valve core of the telescopic cylinder solenoid valve to switch the passage; the boom cylinder pilot reversing valve is used to push the valve core of the boom cylinder solenoid valve to switch the passage.

[0013] In combination with the second aspect, optionally, a logic valve is further included, wherein the logic valve is used to compare the oil pressures of the first input oil circuit and the second input oil circuit, determine the input oil circuit with greater oil pressure between the first input oil circuit and the second input oil circuit, output a pressure signal of the oil pressure of the input oil circuit with greater oil pressure to the hydraulic pump, and the hydraulic pump adjusts the pressure of the output hydraulic oil according to the pressure signal; The pilot valve group is provided with a pressure reducing valve and a filter. The high-pressure oil output by the hydraulic pump is converted into low-pressure oil after being reduced in pressure by the pressure reducing valve. The low-pressure oil is filtered by the filter and then input into the telescopic cylinder pilot reversing valve and the luffing cylinder pilot reversing valve. The low-pressure oil flowing out of the telescopic cylinder pilot reversing valve is input into the telescopic cylinder solenoid valve, and the low-pressure oil flowing out of the luffing cylinder pilot reversing valve is input into the luffing cylinder solenoid valve. The first input oil circuit is the oil circuit output by the telescopic oil cylinder, and the second input oil circuit is the oil circuit output by the luffing oil cylinder.

[0014] In a third aspect, the present invention provides a reach stacker, wherein the reach stacker is equipped with the reach stacker hydraulic control system described in the second aspect.

[0015] Compared with the prior art, the beneficial effects achieved by the spreader control hydraulic circuit, reach stacker hydraulic control system and reach stacker provided by the embodiments of the present invention include: The present invention provides a hydraulic circuit for controlling a spreader, comprising a leveling oil cylinder, a leveling valve group and an oil supply port P1; the leveling valve group comprises a first leveling valve, a second leveling valve and a reversing control valve; the first leveling valve is used to connect the oil supply port P1 with the large-cavity oil port of the leveling oil cylinder, and the second leveling valve is used to connect the oil supply port P1 with the small-cavity oil port of the leveling oil cylinder; when the first leveling valve and the second leveling valve are turned on at the same time, the pressure of the large cavity of the leveling oil cylinder is equal to the pressure of the small cavity, the spreader is in a floating position, and the spreader is adaptively leveled under the action of gravity; the present invention can make the spreader adaptively leveled when the front crane performs an arm raising action or an arm lowering action; The reversing control valve of the present invention is provided with a first conduction mode and a second conduction mode; in the first conduction mode, the oil supply port P1 is connected with the large-chamber oil port of the leveling oil cylinder, and in the second conduction mode, the oil supply port P1 is connected with the small-chamber oil port of the leveling oil cylinder; the inclination direction of the spreader is switched by switching the first conduction mode and the second conduction mode of the reversing control valve; the present invention can switch the inclination direction of the spreader by the operator according to the operator's personal operating habits or ground conditions, so as to meet the working conditions when the ground is at an angle, and facilitate accurate box operation; The present invention can enable the sling to perform adaptive leveling and switch the inclination direction of the sling, thereby reducing the difficulty of hoisting and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the inclination angle α of the sling in the background technology of the present invention; Figure 2 is a schematic diagram of a sling control hydraulic circuit in Example 1 of the present invention; Figure 3 It is a schematic diagram of a hydraulic control system of a reach stacker in Example 2 of the present invention.

[0017] In the figure: 1. Leveling valve group; 102. Check valve; 103. Overflow valve; 104. Overflow pressure reducing valve; 105. First leveling valve; 1051. Electromagnet of first leveling valve; 106. Second leveling valve; 1061. Electromagnet of second leveling valve; 107. Damping regulating valve group; 108. Reversing control valve; 1081. First electromagnet of reversing control valve; 1082. Second electromagnet of reversing control valve; 2. Left leveling cylinder; 3. Right leveling cylinder; 4. Hydraulic pump; 5. Pilot valve group; 501. Pressure reducing valve; 502. First filter; 503. Accumulator; 6. Multi-way valve; 601. Telescopic cylinder solenoid valve; 602. Luffing cylinder solenoid valve; 603. Telescopic cylinder pilot reversing valve; 6031. The first electromagnet of the telescopic cylinder pilot reversing valve; 6032. The second electromagnet of the telescopic cylinder pilot reversing valve; 604. Luffing cylinder pilot reversing valve; 6041. The first electromagnet of the luffing cylinder pilot reversing valve; 6042. The second electromagnet of the luffing cylinder pilot reversing valve; 605. Overload oil replenishing valve; 606. LS unloading valve; 7. Telescopic cylinder; 8. Left luffing cylinder; 9. Right luffing cylinder; 10. Radiator; 11. Second filter; 12. Logic valve; 13. Spreader valve; 14. Boom; 15. Lifting equipment. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. The embodiments of the present invention and the technical features in the embodiments may be combined with each other unless there is a conflict.

[0019] Example 1

[0020] like Figure 2 As shown, this embodiment provides a sling control hydraulic circuit, including: a leveling cylinder, a leveling valve group 1 and an oil supply port P1.

[0021] like Figure 2As shown, in this embodiment, the leveling cylinder includes a left leveling cylinder 2 and a right leveling cylinder 3 respectively arranged on both sides of the spreader in the front and rear directions. The large chambers and small chambers of the left leveling cylinder and the right leveling cylinder are respectively connected to each other so that they can be extended or retracted at the same time to provide sufficient torque for the spreader to tilt forward or backward.

[0022] This embodiment takes the case where one end of the leveling cylinder is installed at the rear of the sling 15 as an example to describe the relationship between the extension and retraction of the leveling cylinder and the tilt direction of the sling.

[0023] like Figure 1 As shown, one end of the leveling cylinder is connected to the boom 14, and the other end is connected to the rear of the sling 15. Figure 1 The middle spreader is in a forward tilted state, in which the piston rod of the leveling cylinder is in an extended state.

[0024] like Figure 2 As shown, the leveling valve group includes a reversing control valve, and a first leveling valve 105 and a second leveling valve 106 that can be turned on at the same time. It also includes a relief pressure reducing valve 104, a relief valve 103, a damping regulating valve group 107 and a plurality of one-way valves 102.

[0025] exist Figure 2 In the figure, for the convenience of display, the corresponding oil inlets of the left leveling cylinder and the right leveling cylinder are named after the pressure measuring ports of the cylinders, including port C-left connected to the large-cavity oil port of the left leveling cylinder, port C+left connected to the small-cavity oil port of the left leveling cylinder, port C-right connected to the large-cavity oil port of the right leveling cylinder, and port C+right connected to the large-cavity oil port of the right leveling cylinder.

[0026] In this embodiment, the oil supply port P1 is connected to the hydraulic pump, the oil drain port D is connected to the oil drain tank storing the drain oil, the oil return port T is connected to the hydraulic oil tank storing the hydraulic oil, and the hydraulic pump pumps the hydraulic oil in the hydraulic oil tank into the oil supply port P.

[0027] The first leveling valve is used to connect the oil supply port P1 with the large oil port of the leveling cylinder, and the second leveling valve is used to connect the oil supply port P1 with the small oil port of the leveling cylinder. When the first leveling valve and the second leveling valve are turned on at the same time, the pressure of the large chamber of the leveling cylinder is equal to the pressure of the small chamber, the spreader is in a floating position, and the spreader is adaptively leveled under the action of gravity.

[0028] The inlet of the first leveling valve is connected to the oil supply port P1, and the outlet is connected to the large chamber oil port of the leveling cylinder. When the electromagnet 1051 of the first leveling valve is energized, the oil supply port P1 is connected to the large chamber of the leveling cylinder, and the hydraulic oil flows from the large chamber through the small chamber and enters the reflux port T.

[0029] The inlet of the second leveling valve is connected to the oil supply port P1, and the outlet is connected to the small chamber oil port of the leveling cylinder. When the electromagnet 1052 of the second leveling valve is energized, the oil supply port P1 is connected to the small chamber of the leveling cylinder, and the hydraulic oil flows from the small chamber through the large chamber and enters the reflux port T.

[0030] The electromagnet 1051 of the first leveling valve and the electromagnet 1052 of the second leveling valve are energized at the same time, the large and small chambers of the leveling cylinder are connected, and the sling is adaptively leveled vertically downward under the action of gravity.

[0031] In this embodiment, if Figure 2 As shown, the oil supply port P1 is connected with the large cavity of the leveling oil cylinder, that is, the oil supply port P1 is connected with the large cavity of the left leveling oil cylinder and the large cavity of the right leveling oil cylinder.

[0032] In this embodiment, if Figure 2 As shown, the oil supply port P1 is connected with the small cavity of the leveling oil cylinder, that is, the oil supply port P1 is connected with the small cavity of the left leveling oil cylinder and the small cavity of the right leveling oil cylinder.

[0033] In this embodiment, if Figure 2 As shown, the first leveling valve and the second leveling valve are both two-position two-way electromagnetic reversing valves.

[0034] The reversing control valve is provided with a first conduction mode and a second conduction mode. In the first conduction mode, the oil supply port P1 is connected to the large chamber oil port of the leveling oil cylinder, and in the second conduction mode, the oil supply port P1 is connected to the small chamber oil port of the leveling oil cylinder. The tilting direction of the spreader is switched by switching the first conduction mode and the second conduction mode of the reversing control valve. The tilting direction of the spreader includes a first direction and a second direction, and the first direction and the second direction are opposite directions.

[0035] like Figure 2 As shown, the reversing control valve includes a first electromagnet 1081 of the reversing control valve and a second electromagnet 1082 of the reversing control valve.

[0036] When the first electromagnet 1081 of the reversing control valve is energized, it is in the first conduction mode, and the oil supply port P1 is connected to the small chamber oil port of the leveling cylinder through the reversing control valve. The hydraulic oil flows from the small chamber of the leveling cylinder through the large chamber and then enters the return port T. The piston rod of the leveling cylinder extends out, and the sling tilts in the first direction.

[0037] In this embodiment, the first direction is the front. Figure 1 , the piston rod of the leveling cylinder extends and the spreader tilts forward.

[0038] When the second electromagnet 1082 of the reversing control valve is energized, it is in the second conduction mode, and the oil supply port P1 is connected to the large chamber oil port of the leveling cylinder through the reversing control valve. The hydraulic oil flows from the large chamber of the leveling cylinder through the small chamber and then enters the return port T. The piston rod of the leveling cylinder retracts, and the sling tilts in the second direction.

[0039] In this embodiment, the second direction is the rear direction. Figure 1 By analogy, when the piston rod of the leveling cylinder retracts, the spreader tilts backward.

[0040] In this embodiment, if Figure 2 As shown, the directional control valve is a three-position four-way solenoid directional valve.

[0041] In this embodiment, the operator can operate the spreader to actively tilt forward or backward according to the operator's personal operating habits or ground conditions to meet the working conditions when the ground is at an angle, thereby facilitating precise box operation.

[0042] The inlet of the relief pressure reducing valve is connected to the oil supply port P1, the outlet of the relief pressure reducing valve is connected to the inlet of the first leveling valve and the inlet of the second leveling valve, and the overflow port of the relief pressure reducing valve is connected to the oil drain port D on the leveling valve body.

[0043] In this embodiment, the overflow pressure reducing valve is a pressure-adjustable overflow pressure reducing valve.

[0044] like Figure 2 As shown, a one-way valve is provided between the overflow port and the oil drain port D of the overflow pressure reducing valve to prevent the overflowing oil in the oil drain cylinder from interfering with the overflow pressure reducing valve.

[0045] The inlet of the damping regulating valve group is connected to the oil supply port P1, and the outlet is connected to the oil port C-left, the oil port C+left, the oil port C-right, and the oil port C+right.

[0046] The damping regulating valve group is used to adjust the forward and backward tilt of the spreader. The damping regulating valve group can slow down the forward and backward tilting movements.

[0047] Specifically, the damping regulating valve group includes a throttle hole with a large aperture and a throttle hole with a small aperture.

[0048] The outlet of the large-diameter throttle hole is connected to the oil port C-left and the oil port C-right, and the hydraulic oil is connected to the large-cavity oil port of the leveling cylinder through the large-diameter throttle hole. A one-way valve is connected in parallel with the large-diameter throttle hole, and the allowed flow direction is from the outlet of the large-diameter throttle hole to the inlet, which is used to ensure that the hydraulic oil flows through the large-diameter throttle hole.

[0049] The outlet of the small-diameter throttle hole is connected to the oil port C+left and the oil port C+right, and the hydraulic oil is connected to the cavity oil port of the leveling cylinder through the small-diameter throttle hole. A one-way valve is connected in parallel with the small-diameter throttle hole, and the allowed flow direction is from the outlet of the small-diameter throttle hole to the inlet, which is used to ensure that the hydraulic oil flows through the small-diameter throttle hole.

[0050] In this embodiment, if Figure 2As shown, the leveling valve body is provided with a pressure measuring port MP-, which is used to measure the pressure of the large chamber of the left leveling oil cylinder and the right leveling oil cylinder. The leveling valve body is provided with a pressure measuring port MP+, which is used to measure the pressure of the small chamber of the left leveling oil cylinder and the right leveling oil cylinder.

[0051] The spreader control hydraulic circuit provided in this embodiment can enable the spreader to perform adaptive leveling, and control the forward and backward tilt of the spreader, thereby reducing the difficulty of lifting and improving work efficiency.

[0052] Example 2

[0053] like Figure 3 As shown, this embodiment provides a hydraulic control system for a reach stacker, comprising: a hydraulic pump 4 and a spreader control hydraulic circuit provided in Embodiment 1. The outlet of the hydraulic pump is connected to the oil supply port P1 of the spreader control hydraulic circuit.

[0054] In this embodiment, a hydraulic control system for a reach stacker is configured with a drain oil tank for storing drain oil and a hydraulic oil tank for storing hydraulic oil, the drain oil tank is connected to a drain oil port D of a hydraulic circuit for controlling a spreader, and the hydraulic oil tank is connected to an oil return port T of a hydraulic circuit for controlling a spreader. The hydraulic pump pumps the hydraulic oil in the hydraulic oil tank into the oil supply port P1.

[0055] A front crane hydraulic control system also includes a boom working hydraulic circuit.

[0056] The boom working hydraulic circuit includes a pilot valve group 5, a multi-way valve 6, an actuator cylinder and an oil supply port P2. The oil supply port P2 is connected to the outlet of the hydraulic pump.

[0057] like Figure 3 As shown, the executing cylinder includes a telescopic cylinder 7 and a luffing cylinder.

[0058] When the multi-way valve connects the oil circuit between the oil supply port P2 and the telescopic cylinder, the piston rod of the telescopic cylinder extends or retracts to control the telescopic operation of the boom.

[0059] When the multi-way valve connects the oil circuit between the oil supply port P2 and the luffing cylinder, the piston rod of the luffing cylinder extends or retracts to control the luffing operation of the boom.

[0060] In this embodiment, the luffing cylinders include a left luffing cylinder 8 and a right luffing cylinder 9, and the two luffing cylinders perform the same operation at the same time. The two luffing cylinders are provided to meet the flow required for the luffing work and to improve the balance of the left and right sides of the spreader during adjustment.

[0061] The multi-way valve includes an oil drain port D, an oil return port T, a pilot control oil port Ps, a feedback control oil port Ls, and oil ports A1 and A1' for connecting the large chamber of the telescopic cylinder, oil ports B1 and B1' for connecting the small chamber of the telescopic cylinder, oil port A2 for connecting the large chamber of the left boom cylinder, oil port B2 for connecting the small chamber of the left boom cylinder, oil port A2' for connecting the large chamber of the right boom cylinder, and oil port B2' for connecting the small chamber of the left boom cylinder.

[0062] The multi-way valve includes a telescopic cylinder solenoid valve 601, a telescopic cylinder pilot reversing valve 603, a variable amplitude cylinder solenoid valve 602 and a variable amplitude cylinder pilot reversing valve 604. The telescopic cylinder pilot reversing valve is used to push the valve core of the telescopic cylinder solenoid valve to switch the passage. The variable amplitude cylinder pilot reversing valve is used to push the valve core of the variable amplitude cylinder solenoid valve to switch the passage.

[0063] In this embodiment, the telescopic cylinder solenoid valve and the variable-length cylinder solenoid valve are both three-position seven-way solenoid valves. The telescopic cylinder pilot reversing valve includes a first electromagnet 6031 of the telescopic cylinder pilot reversing valve and a second electromagnet 6032 of the telescopic cylinder pilot reversing valve, and the variable-length cylinder pilot reversing valve includes a first electromagnet 6041 of the variable-length cylinder pilot reversing valve and a second electromagnet 6042 of the variable-length cylinder pilot reversing valve.

[0064] When the first electromagnet 6031 of the telescopic cylinder pilot reversing valve is energized and the second electromagnet 6032 of the telescopic cylinder pilot reversing valve is not energized, Figure 3 The valve core of the solenoid valve of the middle telescopic cylinder moves downward, the oil supply port P2 is connected with the oil port B1 and the oil port B1' of the small cavity of the telescopic cylinder, the oil supply port P2 is connected with the small cavity of the telescopic cylinder, the hydraulic oil flows from the small cavity into the large cavity, the piston rod of the telescopic cylinder extends, and the hydraulic oil enters the reflux port T through the solenoid valve of the telescopic cylinder.

[0065] When the first electromagnet 6031 of the telescopic cylinder pilot reversing valve is not energized and the second electromagnet 6032 of the telescopic cylinder pilot reversing valve is energized, Figure 3 The valve core of the solenoid valve of the middle telescopic cylinder moves upward, the oil supply port P2 is connected with the oil port A1 and oil port A1' of the large cavity of the telescopic cylinder, the oil supply port P2 is connected with the large cavity of the telescopic cylinder, the hydraulic oil flows from the large cavity into the large cavity, the piston rod of the telescopic cylinder retracts, and the hydraulic oil enters the reflux port T through the solenoid valve of the telescopic cylinder.

[0066] When the first electromagnet 6041 of the pilot reversing valve of the luffing cylinder is energized and the second electromagnet 6042 of the pilot reversing valve of the luffing cylinder is not energized, Figure 3 The valve core of the solenoid valve of the middle luffing cylinder moves downward, the oil supply port P2 is connected with the oil port B2 and the oil port B2' of the small cavity of the luffing cylinder, the oil supply port P2 is connected with the small cavity of the luffing cylinder, the hydraulic oil flows from the small cavity into the large cavity, the piston rod of the luffing cylinder extends, and the hydraulic oil enters the reflux port T through the solenoid valve of the luffing cylinder.

[0067] When the first electromagnet 6041 of the pilot reversing valve of the variable-luffing oil cylinder is not energized and the second electromagnet 6042 of the pilot reversing valve of the variable-luffing oil cylinder is energized, Figure 3 The valve core of the solenoid valve of the middle luffing cylinder moves upward, the oil supply port P2 is connected with the oil port A2 and the oil port A2' of the large cavity of the luffing cylinder, the oil supply port P2 is connected with the large cavity of the luffing cylinder, the hydraulic oil flows from the large cavity into the large cavity, the piston rod of the luffing cylinder retracts, and the hydraulic oil enters the reflux port T through the solenoid valve of the luffing cylinder.

[0068] The multi-way valve also includes an overload oil replenishment valve 605 and an LS unloading valve 606. The overload oil replenishment valve is used to prevent the cylinder from being overloaded and to prevent the cylinder from sucking in the hole when the cylinder is quickly started, and to replenish the cylinder with oil. The LS unloading valve is used to discharge the excess LS oil into the return port T when the cylinder is not performing an action.

[0069] In this embodiment, a radiator 10 for cooling the hydraulic oil and a second filter 11 for ensuring the cleanliness of the hydraulic oil are arranged between the oil return port T of the multi-way valve and the hydraulic oil tank.

[0070] The hydraulic control system of the front crane also includes a pilot valve group 5. The inlet of the pilot valve group is connected to the outlet of the hydraulic pump, and the outlet of the pilot valve group is connected to the pilot reversing valve of the telescopic cylinder and the pilot reversing valve of the variable amplitude cylinder. The pilot valve group is used to process the hydraulic oil and then input it into the control oil circuit of the multi-way valve.

[0071] Specifically, the pilot valve group is provided with a pressure reducing valve 501 and a first filter 502. The high-pressure oil output by the hydraulic pump is reduced in pressure by the pressure reducing valve and converted into low-pressure oil required by the control oil circuit. The low-pressure oil is filtered by the filter and input into the telescopic cylinder pilot reversing valve and the luffing cylinder pilot reversing valve from the pilot control oil port Ps. The low-pressure oil flowing out of the telescopic cylinder pilot reversing valve is input into the telescopic cylinder solenoid valve, and the low-pressure oil flowing out of the luffing cylinder pilot reversing valve is input into the luffing cylinder solenoid valve.

[0072] The boom working hydraulic circuit also includes a logic valve 12. The logic valve is used to compare the oil pressures of the first input oil circuit and the second input oil circuit, determine the input oil circuit with greater oil pressure between the first input oil circuit and the second input oil circuit, and output the pressure signal of the oil pressure of the input oil circuit with greater oil pressure to the hydraulic pump. The hydraulic pump adjusts the pressure of the output hydraulic oil according to the pressure signal.

[0073] Specifically, the logic valve outputs a pressure signal from the feedback control oil port Ls to the hydraulic pump, and the low-pressure oil discharged from the logic valve enters the return port T.

[0074] Among them, the first input oil circuit is the oil circuit output by the telescopic oil cylinder, and the second input oil circuit is the oil circuit output by the amplitude-changing oil cylinder.

[0075] In this embodiment, an accumulator 503 and a relief valve are further provided in the pilot valve group after the pressure reducing valve. The accumulator is used to store hydraulic oil for the control oil circuit. In this embodiment, the relief valve is a 40 bar relief valve, which is used to overflow the excess hydraulic oil when the accumulator pressure reaches 40 bar.

[0076] like Figure 3 As shown, in this embodiment, a spreader valve 13 is also provided, and the spreader valve includes a relief pressure reducing valve, a relief valve and a reversing valve. When the spreader control hydraulic circuit performs adaptive leveling control, spreader forward tilt control or spreader backward tilt control, the electromagnet of the reversing valve is energized, and the pressure signal is output from the feedback control oil port Ls to the hydraulic pump. The hydraulic pump outputs hydraulic oil to the oil supply port P of the leveling valve body. The relief pressure reducing valve is used to reduce the high-pressure hydraulic oil output by the hydraulic pump to the pressure required by the leveling cylinder. The relief valve is used to prevent the leveling cylinder from overloading.

[0077] In this embodiment, if Figure 3 As shown in the figure, the hydraulic pumps are two hydraulic pumps connected in parallel. The hydraulic pumps are variable displacement pumps.

[0078] like Figure 3 As shown, a hydraulic pump controller is connected to the hydraulic pump, and the hydraulic pump controller is used to adjust the pressure of the hydraulic oil output by the hydraulic pump according to the pressure signal output by the feedback control oil port Ls. A pump outlet check valve group is provided at the hydraulic pump outlet to prevent the hydraulic oil from flowing back.

[0079] Furthermore, a front loaders hydraulic control system is also provided with a load-carrying equipment operating cylinder connected to the load-carrying equipment. This configuration is similar to the existing setting and will not be discussed in detail in this embodiment.

[0080] This embodiment is combined with a spreader control hydraulic circuit provided in Embodiment 1 to describe the adaptive leveling of the spreader when the reach crane performs an arm raising or arm lowering action.

[0081] When the front crane is lifting its arm, the hydraulic pump supplies oil, the pilot reversing valve of the luffing cylinder is started, pushing the valve core of the luffing cylinder solenoid valve, and the hydraulic oil enters the small chamber of the luffing cylinder after oil supply adjustment by the multi-way valve. The piston rod of the luffing cylinder extends, lifting the front crane's arm and raising the spreader. At this time, the controller detects that the multi-way valve is energized, and at the same time, the first leveling valve and the second leveling valve in the spreader control hydraulic circuit are energized. The large and small chambers of the leveling cylinder are connected, and the spreader is in a floating position, moving vertically downward under the action of gravity, realizing the adaptive leveling control of the spreader during the lifting action.

[0082] When the front crane lowers its arm, the hydraulic pump supplies oil, the pilot reversing valve of the luffing cylinder starts, pushing the valve core of the luffing cylinder solenoid valve. After the hydraulic oil is regulated by the multi-way valve, it enters the large chamber of the luffing cylinder, the piston rod of the luffing cylinder retracts, the front crane's arm falls, and the spreader falls. At this time, the controller detects that the multi-way valve is energized, and at the same time, the first leveling valve and the second leveling valve in the spreader control hydraulic circuit are energized. The large and small chambers of the leveling cylinder are connected, and the spreader is in a floating position, and moves vertically downward under the action of gravity, realizing the adaptive leveling control of the spreader when the arm is lowered.

[0083] Example 3

[0084] This embodiment provides a reach stacker, which is equipped with the reach stacker hydraulic control system described in Example 2.

[0085] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A spreader control hydraulic circuit, characterized in that: It includes a leveling cylinder, a leveling valve group and an oil supply port P1; The leveling valve group includes a first leveling valve, a second leveling valve and a reversing control valve; The first leveling valve is used to connect the oil supply port P1 with the large chamber oil port of the leveling oil cylinder, and the second leveling valve is used to connect the oil supply port P1 with the small chamber oil port of the leveling oil cylinder; when the first leveling valve and the second leveling valve are turned on at the same time, the pressure of the large chamber of the leveling oil cylinder is equal to the pressure of the small chamber, the spreader is in a floating position, and the spreader is adaptively leveled under the action of gravity; The reversing control valve is provided with a first conduction mode and a second conduction mode; in the first conduction mode, the oil supply port P1 is connected with the large-chamber oil port of the leveling cylinder, and in the second conduction mode, the oil supply port P1 is connected with the small-chamber oil port of the leveling cylinder; the inclination direction of the sling is switched by switching the first conduction mode and the second conduction mode through the reversing control valve.

2. The spreader control hydraulic circuit according to claim 1, characterized in that: The spreader control hydraulic circuit also includes a return port T; The inlet of the first leveling valve is connected to the oil supply port P1, and the outlet is connected to the large chamber oil port of the leveling cylinder. When the electromagnet of the first leveling valve is energized, the oil supply port P1 is connected to the large chamber of the leveling cylinder, and the hydraulic oil flows from the large chamber through the small chamber and enters the return port T; The inlet of the second leveling valve is connected to the oil supply port P1, and the outlet is connected to the small chamber oil port of the leveling cylinder. When the electromagnet of the second leveling valve is energized, the oil supply port P1 is connected to the small chamber of the leveling cylinder, and the hydraulic oil flows from the small chamber through the large chamber and then enters the return port T; The electromagnet of the first leveling valve and the electromagnet of the second leveling valve are energized at the same time, the large and small chambers of the leveling cylinder are connected, and the sling is adaptively leveled vertically downward under the action of gravity.

3. The spreader control hydraulic circuit according to claim 1, characterized in that: The spreader control hydraulic circuit further includes a return port T, the reversing control valve includes a first electromagnet and a second electromagnet, the spreader tilting direction includes a first direction and a second direction, and the first direction and the second direction are opposite directions; When the first electromagnet is energized, it is in the first conduction mode, the oil supply port P1 is connected to the small chamber oil port of the leveling cylinder through the reversing control valve, the hydraulic oil flows from the small chamber of the leveling cylinder through the large chamber and then enters the return port T, the piston rod of the leveling cylinder extends, and the sling is tilted in the first direction; When the second electromagnet is energized, it is in the second conduction mode, the oil supply port P1 is connected to the large chamber oil port of the leveling cylinder through the reversing control valve, the hydraulic oil flows from the large chamber of the leveling cylinder through the small chamber and then enters the return port T, the piston rod of the leveling cylinder retracts, and the sling tilts in the second direction.

4. The spreader control hydraulic circuit according to claim 1, characterized in that: The sling control hydraulic circuit also includes an oil drain port D and a relief pressure reducing valve; The inlet of the relief pressure reducing valve is connected to the oil supply port P1, the outlet of the relief pressure reducing valve is connected to the inlet of the first leveling valve and the inlet of the second leveling valve, and the overflow port of the relief pressure reducing valve is connected to the oil drain port D on the valve body of the leveling valve.

5. The spreader control hydraulic circuit according to claim 1, characterized in that: The spreader control hydraulic circuit also includes a damping regulating valve group for damping the spreader tilt, and the damping regulating valve group includes a large-aperture throttle hole and a small-aperture throttle hole; The inlet of the damping regulating valve group is connected to the oil supply port P1, the hydraulic oil is connected to the large-cavity oil port of the leveling cylinder through the large-diameter throttle hole, and the hydraulic oil is connected to the small-cavity oil port of the leveling cylinder through the small-diameter throttle hole.

6. A hydraulic control system for a front loaders, characterized in that: include: A hydraulic pump and a spreader control hydraulic circuit as claimed in any one of claims 1 to 5, wherein the outlet of the hydraulic pump is connected to the oil supply port P1 of the spreader control hydraulic circuit.

7. The hydraulic control system of a reach stacker according to claim 6, characterized in that: It also includes a boom working hydraulic circuit, which includes a multi-way valve, an actuator cylinder and an oil supply port P2, and the actuator cylinder includes a telescopic cylinder and a luffing cylinder; the oil supply port P2 is connected to the outlet of the hydraulic pump; When the multi-way valve connects the oil circuit between the oil supply port P2 and the telescopic cylinder, the piston rod of the telescopic cylinder extends or retracts to control the telescopic operation of the boom; When the multi-way valve connects the oil circuit between the oil supply port P2 and the luffing cylinder, the piston rod of the luffing cylinder extends or retracts to control the luffing operation of the boom.

8. The hydraulic control system for a reach stacker according to claim 7, characterized in that: The multi-way valve includes a telescopic cylinder solenoid valve, a telescopic cylinder pilot reversing valve, a luffing cylinder solenoid valve and a luffing cylinder pilot reversing valve, and the front crane hydraulic control system also includes a pilot valve group; The inlet of the pilot valve group is connected to the outlet of the hydraulic pump, and the outlet of the pilot valve group is connected to the telescopic cylinder pilot reversing valve and the boom cylinder pilot reversing valve; the telescopic cylinder pilot reversing valve is used to push the valve core of the telescopic cylinder solenoid valve to switch the passage; the boom cylinder pilot reversing valve is used to push the valve core of the boom cylinder solenoid valve to switch the passage.

9. The hydraulic control system for a reach stacker according to claim 8, characterized in that: It also includes a logic valve, the logic valve is used to compare the oil pressures of the first input oil circuit and the second input oil circuit, determine the input oil circuit with greater oil pressure between the first input oil circuit and the second input oil circuit, output a pressure signal of the oil pressure of the input oil circuit with greater oil pressure to the hydraulic pump, and the hydraulic pump adjusts the pressure of the output hydraulic oil according to the pressure signal; The pilot valve group is provided with a pressure reducing valve and a filter. The high-pressure oil output by the hydraulic pump is converted into low-pressure oil after being reduced in pressure by the pressure reducing valve. The low-pressure oil is filtered by the filter and then input into the telescopic cylinder pilot reversing valve and the luffing cylinder pilot reversing valve. The low-pressure oil flowing out of the telescopic cylinder pilot reversing valve is input into the telescopic cylinder solenoid valve, and the low-pressure oil flowing out of the luffing cylinder pilot reversing valve is input into the luffing cylinder solenoid valve. The first input oil circuit is the oil circuit output by the telescopic oil cylinder, and the second input oil circuit is the oil circuit output by the luffing oil cylinder.

10. A reach stacker, characterized in that: The reach stacker is equipped with a reach stacker hydraulic control system as described in any one of claims 5-9.

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