Hydraulic synchronous flow control system applied to multiple jacking mechanisms and jacking device
By using a hydraulic synchronous flow control system, which forms a hydraulic circuit with components such as relief valves and directional valves, the problem of synchronous movement of multiple lifting mechanisms in heavy industry is solved, achieving low-cost and highly reliable synchronous lifting effect, and ensuring load uniformity and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-23
- Publication Date
- 2026-03-31
AI Technical Summary
In the heavy industry sector, existing technologies struggle to achieve synchronized movement of multiple lifting mechanisms in high-cost and complex environments, leading to uneven load distribution and potential safety hazards.
A hydraulic synchronous flow control system is adopted, which forms a hydraulic circuit through components such as relief valves and directional valves to ensure consistent oil pressure in each lifting mechanism. The relief valve balances the oil pressure, the throttle valve controls the flow, and the mechanical limit switch achieves synchronous lifting.
It achieves synchronous lifting of multiple lifting mechanisms under low cost and high reliability conditions, avoiding structural deformation and safety accidents, and improving synchronization accuracy and reliability.
Smart Images
Figure CN224062369U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lifting mechanism technology, specifically to a hydraulic synchronous flow control system and lifting device applied to multiple lifting mechanisms. Background Technology
[0002] In heavy industries such as metallurgy, heavy equipment manufacturing, and the installation and maintenance of large structural components, it is often necessary to horizontally lift and precisely level large loads. Such operations typically rely on the coordinated work of multiple lifting mechanisms. However, if the lifting height of each support point is not consistent during the lifting process, it will lead to severely uneven stress on the load, which can easily cause structural deformation, equipment damage, or even overturning accidents. Therefore, achieving synchronous movement between multiple lifting platforms is a core requirement for ensuring operational safety and precision.
[0003] Currently, mainstream technologies and practices in the industry focus on high-precision synchronous control throughout the lifting process. The most representative solution is the closed-loop electro-hydraulic proportional / servo synchronous system. This system equips each lifting cylinder with a high-precision displacement sensor for real-time position feedback. A central controller (such as a PLC) calculates the synchronization based on a pre-defined algorithm (such as master-slave control) and drives high-performance electro-hydraulic proportional valves or servo valves to dynamically adjust the oil flow rate of each cylinder, thereby striving to maintain consistent height at each lifting point throughout the entire lifting stroke. While this technology can achieve high synchronization accuracy and dynamic performance in laboratory or ideal working conditions, its inherent shortcomings are fully exposed in complex heavy industrial environments: First, the system is extremely complex, involving numerous precision sensors, controllers, and high-response valves, resulting in exceptionally high costs. Second, the system is extremely sensitive to the working environment; the reliability of its precision components significantly decreases under common conditions such as dust, vibration, electromagnetic interference, and oil contamination, leading to high failure rates and difficult and costly maintenance. Large loads refer to large, easily deformable loads, such as steel plates.
[0004] Therefore, in cost-sensitive and environmentally harsh heavy industrial settings, the industry has long faced a dilemma: either bear the high costs and maintenance burdens of adopting high-precision electro-hydraulic synchronization systems, or find it difficult to reliably achieve safe leveling of large loads. Utility Model Content
[0005] This utility model addresses the leveling problem of large loads in existing heavy industrial scenarios by providing a hydraulic synchronous flow control system and a lifting device applicable to multiple lifting mechanisms. The specific technical solution is as follows:
[0006] A hydraulic synchronous flow control system for multiple lifting mechanisms includes an oil tank, characterized in that it further includes: several lifting branches connected to the oil tank, each lifting branch being a hydraulic circuit formed by a single directional valve, several synchronous motors, and several single-rod bidirectional cylinders, to drive several lifting mechanisms with identical structures to lift and lower; several return branches with oil inlets located between the oil tank and the directional valves, the oil outlets of the return branches being connected to the oil tank, and the return branches being hydraulic circuits formed by relief valves; when the internal oil pressure of the lifting branch applied to a single lifting mechanism is greater than a preset oil pressure, the return branch corresponding to the lifting mechanism is connected to balance the internal oil pressure of the lifting branch.
[0007] Furthermore, the overflow valve forms an oil inlet P2 connected to the oil tank and an oil outlet T2 connected to the oil tank.
[0008] The preset oil pressure corresponds to the internal spring pressure of the overflow valve. When the internal oil pressure of the lifting branch is greater than the internal spring pressure, the oil inlet P2 and the oil outlet T2 are connected.
[0009] Preferably, the reversing valve is a three-position four-way solenoid valve.
[0010] Preferably, the single-rod bidirectional hydraulic cylinder forms a rod-type cavity connected to the lifting mechanism and a rodless cavity away from the lifting mechanism;
[0011] The lifting circuit also includes a balance valve installed on the oil line connecting the synchronous motor and the single-rod double-acting cylinder;
[0012] The load port A3 of the balance valve is connected to the rodless chamber of the single-rod double-acting hydraulic cylinder, and the oil outlet B3 of the balance valve is connected to the oil tank.
[0013] Preferably, the lifting branch also includes two throttle valves;
[0014] Throttle valve 1's working port A4 is connected to the directional valve's working port A1. Throttle valve 1's working port A5 is also connected to the rod chamber of all single-rod bidirectional hydraulic cylinders. Throttle valve 2's working port A6 is connected to the directional valve's working port B1. Throttle valve 2's working port A7 is also connected to the working ports of all synchronous motors.
[0015] Preferably, it also includes a hydraulic pump connected to the oil tank, a motor driving the hydraulic pump, and a controller controlling the motor. The oil outlet of the hydraulic pump is connected to the oil inlet P1 of all directional valves, and the oil return port T1 of the directional valves is connected to the same oil tank.
[0016] Preferably, the lifting branch also includes:
[0017] A pressure gauge installed between the outlet of the hydraulic pump and the inlet P1 of the directional valve; and
[0018] The return oil filter is installed on the branch line between the return oil port T1 of the reversing valve and the oil tank.
[0019] Preferably, it also includes several adjustable height mechanical limiters, which form the highest point of the single lifting mechanism. When the lifting mechanism rises and contacts the mechanical limiters, the internal oil pressure of the lifting branch increases.
[0020] A lifting device includes a hydraulic synchronous flow control system, which is applied to several lifting mechanisms to unify the height of the highest lifting point of the lifting mechanisms.
[0021] As can be seen from the above technical solution, this utility model has the following beneficial effects:
[0022] This utility model uses a lifting branch to drive the lifting mechanism to raise and lower until the lifting mechanism rises and contacts the mechanical limit to fix the final raised position. At the same time, an overflow valve is set to reduce and keep the internal oil pressure of the lifting branch that is continuously increasing and too high, so as to ensure that the internal oil pressure of all lifting branches eventually tends to be consistent. This also makes the top of multiple lifting mechanisms form a horizontal surface for bearing, achieving low cost and high reliability of horizontal leveling. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of Embodiment 1 of the present utility model;
[0024] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present invention;
[0025] Figure 3 for Figure 2 Enlarged view of the structure at point C.
[0026] In the diagram: 101, oil tank; 102, motor; 103, hydraulic pump; 104, relief valve; 105, pressure gauge; 106, directional valve; 107, throttle valve; 108, balance valve; 109, synchronous motor; 110, single-rod double-acting hydraulic cylinder; 111, return oil filter; 112, controller; 113, mechanical limit switch; 200, lifting mechanism. Detailed Implementation
[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0028] In the description of the embodiments of this utility model, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0029] Example 1
[0030] like Figure 1 As shown, this embodiment is a hydraulic synchronous flow control system applied to multiple lifting mechanisms 200, including an oil tank 101, which further includes: several lifting branches connected to the oil tank 101, each lifting branch being a hydraulic oil circuit formed by a single reversing valve 106, several synchronous motors 109, and several single-rod double-acting cylinders 110, to drive several lifting mechanisms 200 with the same structure to lift and lower respectively; several return branches with oil inlets set between the oil tank 101 and the reversing valve 106, the oil outlets of the return branches being connected to the oil tank 101, and the return branches being a hydraulic circuit formed by an overflow valve 104; when the internal oil pressure of the lifting branch applied to a single lifting mechanism 200 is greater than the preset oil pressure, the return branch corresponding to the lifting mechanism 200 is connected to balance the internal oil pressure of the lifting branch.
[0031] Specifically, this embodiment includes an oil tank 101 and eight lifting mechanisms 200. The eight lifting mechanisms 200 have identical structures, and each is controlled independently by a separate lifting branch and a return branch, improving the independence of their lifting operations. Secondly, in each lifting branch, the reversing valve 106 simultaneously supplies oil to two synchronous motors 109. The two synchronous motors 109 then forcefully deliver the same volume of hydraulic oil to two single-rod double-acting cylinders 110, enabling the two cylinders to lift synchronously. This ensures that the top of each lifting mechanism 200 remains horizontal during lifting. This changes the existing method of synchronizing the two cylinders using a high-precision displacement sensor to synchronizing them by delivering the same volume of hydraulic oil, ensuring synchronization accuracy, reducing synchronization costs, and improving synchronization reliability.
[0032] Secondly, the single-group return branch includes an overflow valve 104. The oil inlet P2 of the overflow valve 104 is connected to the common oil tank 101 for oil intake, and the oil outlet T2 of the overflow valve 104 is also connected to the common oil tank 101 for oil return, forming a complete circuit. The main function of the overflow valve 104 is pressure limiting. It is determined by the oil pressure at the oil inlet P2 to open or close, so that excess hydraulic oil flows back to the oil tank 101 through the oil outlet T2, thereby limiting the maximum system pressure to the set value.
[0033] Secondly, the eight lifting mechanisms 200 rise simultaneously under the drive of the eight lifting branches, with different rising rates, so that they reach the preset endpoint at different times. When the moving end of a certain lifting mechanism 200 reaches the preset endpoint first and cannot continue to rise, the oil tank 101 continuously supplies oil to that lifting mechanism 200, increasing its internal oil pressure until it exceeds the set value of the overflow valve 104 applied to that lifting mechanism 200, connecting its internal oil inlet P2 and oil outlet T2. This allows the hydraulic oil supplied by the oil tank 101 to that lifting mechanism 200 to return to the oil tank 101 through the oil inlet P2 and oil outlet T2, keeping the internal oil pressure of that lifting branch constant. This continues until the internal oil pressure of all eight lifting branches is constant, and the moving ends of all eight lifting mechanisms 200 reach the preset endpoint position, placing their moving ends on the same horizontal plane, thus achieving a low-cost, highly reliable horizontal working surface.
[0034] Furthermore, the overflow valve 104 forms an oil inlet P2 connected to the oil tank 101 and an oil outlet T2 connected to the oil tank 101; the preset oil pressure corresponds to the internal spring pressure of the overflow valve 104, and when the internal oil pressure of the lifting branch is greater than the internal spring pressure, the oil inlet P2 and the oil outlet T2 are connected.
[0035] Specifically, the left end of the relief valve 104 forms an oil inlet P2, and the right end forms an oil outlet T2. It mainly includes a valve body, a valve core that is subjected to spring force within the valve body, and a handwheel or screw for adjusting the spring preload. The operator adjusts the spring preload according to the highest pressure that the lifting branch can stably withstand, so that when the internal oil pressure of the lifting branch reaches the highest pressure, it can just overcome the internal spring force of the relief valve 104. The highest pressure is the preset oil pressure of the relief valve 104. As a result, when the oil tank 101 continues to supply oil to the lifting branch, the internal oil pressure of the lifting branch exceeds the preset oil pressure of the relief valve 104, the valve core of the relief valve 104 moves, and the oil inlet P2 and the oil outlet T2 are connected, ensuring that the internal oil pressure of the lifting branch is always maintained at the preset oil pressure of the relief valve 104.
[0036] Furthermore, the directional valve 106 is a three-position four-way solenoid valve. Specifically, the directional valve 106 forms an inlet port P1 connected to the oil tank 101, a return port T1 connected to the oil tank 101, a working port A1 connected to the rod chamber of the single-rod double-acting cylinder 110, and a working port B1 connected to the rodless chamber of the single-rod double-acting cylinder 110. When the directional valve 106 is in the neutral position, the inlet port P1 is not connected to the working ports A1 and B1, and the return port T1 is connected to the working ports A1 and B1, and the moving end of the lifting mechanism 200 is in a no-load floating state; when the directional valve 106 is switched to the upper position by the internal electromagnetic drive mechanism, the inlet port P1 is connected to the working port A1, and the return port T1 is connected to the working port B1, so that the hydraulic oil passes sequentially through the inlet port P1 and the working port A1 to the rod chamber of the single-rod double-acting cylinder 110, and the hydraulic oil... The hydraulic oil flows sequentially through the rodless chamber of the single-rod double-acting cylinder 110, through the working port B1, to the return port T1, and the lifting mechanism 200 is in a descending state. When the reversing valve 106 switches to the lower position, the inlet port P1 is connected to the working port B1, and the return port T1 is connected to the working port A1, so that the hydraulic oil flows sequentially through the inlet port P1, the working port B1 to the rodless chamber of the single-rod double-acting cylinder 110, and sequentially through the rod chamber of the single-rod double-acting cylinder 110, through the working port A1, to the return port T1, and the lifting mechanism 200 is in an ascending state.
[0037] Furthermore, the single-rod bidirectional hydraulic cylinder 110 forms a rod chamber connected to the lifting mechanism 200 and a rodless chamber away from the lifting mechanism 200; the lifting branch also includes a balance valve 108 disposed between the synchronous motor 109 and the oil circuit connecting the single-rod bidirectional hydraulic cylinder 110; the load port A3 of the balance valve 108 is connected to the rodless chamber of the single-rod bidirectional hydraulic cylinder 110, and the oil outlet B3 of the balance valve 108 is connected to the oil tank 101.
[0038] Specifically, the upper part of the single-rod double-acting hydraulic cylinder 110 is the rod chamber, and the lower part is the rodless chamber. The rod chamber is connected to the moving end of the lifting mechanism 200, driving it to rise and fall. The rodless chamber cooperates with the rod chamber to stabilize the rising and falling of the moving end of the lifting mechanism 200. Secondly, a single balance valve 108 is set in the oil circuit between the single single-rod double-acting hydraulic cylinder 110 and the single synchronous motor 109. In the figure, the balance valve 108 is a balance circuit composed of a sequence valve with an external vent T3 and a check valve connected in parallel. The sequence valve usually includes a main valve core, a control piston, and a pressure regulating spring (the balance valve 108 is a conventional product, and its internal structure is not shown in the figure). At the same time, the black solid triangle at the bottom of the valve core is the external vent T3, which is connected to the outside. The specific process of applying the balance valve 108 to the single-rod double-acting cylinder 110 is as follows: When in a static state, the directional valve 106 and the oil tank 101 do not supply oil. Under the action of gravity, the load presses down on the rod chamber of the single-rod double-acting cylinder 110, causing the oil pressure in its rodless chamber to rise, that is, the pressure at the load port A3 to rise. At this time, the sequence valve is in the normally closed position under the action of the pressure regulating spring, and the check valve below is also in the cut-off state due to the reverse connection. The oil is trapped in the rodless chamber, and the moving end of the lifting mechanism 200 and the load cannot fall. When the directional valve 106 supplies oil to the rod chamber through A1, causing it to continue to descend, the pressure at the load port A3... Force is applied to the valve core of the sequence valve through the internal pilot line (the dotted line above the box in the figure). When the pressure at the load port A3 rises and exceeds the set value of the pressure regulating spring at the bottom of the sequence valve, the valve core is pushed open, and its internal flow channel is connected, so that the load port A3 and the return port B3 are connected. The sequence valve only allows oil to flow from the load port A3 to the return port B3 and the oil tank 101 with a certain resistance. This resistance (back pressure) is the same as the load weight, so that the two cancel each other out. This allows the single-rod double-acting cylinder 110 to descend smoothly and at a constant speed under the drive of the oil supply from the lifting branch, ensuring the stable descent of the moving end of the lifting mechanism 200.
[0039] Furthermore, the lifting branch also includes two throttle valves 107; the working port A4 of throttle valve 107-1 is connected to the working port A1 of the directional valve 106, the working port A5 of throttle valve 107-1 is simultaneously connected to the rod chamber of all single-rod bidirectional cylinders 110, the working port A6 of throttle valve 107-2 is connected to the working port B1 of the directional valve 106, and the working port A7 of throttle valve 107-2 is simultaneously connected to the working ports of all synchronous motors 109.
[0040] Specifically, the throttle valve 107 includes a left-side throttle valve 107-1 and a right-side throttle valve 107-2. Throttle valve 107-1 and check valve 1, and throttle valve 107-2 and check valve 2 are connected in parallel to form a throttle circuit. Secondly, when the directional valve 106 is in the upper position, the inlet port P1 is connected to the working port A1. Working port A1 flows to the working port A6 of throttle valve 107-2 and check valve 2. Because check valve 2 is in the connected state, there is flow resistance in throttle valve 107-2, causing hydraulic oil to flow through check valve 2 into the two rod chambers, pushing the two single-rod bidirectional cylinders 110 downwards. When the directional valve 106 is in the lower position, the inlet port P1 is connected to the working port B1. Working port B1 flows to the working port A4 of throttle valve 107-1 and check valve 1. Because check valve 107-1 is in the connected state, there is flow resistance in throttle valve 107-2, causing hydraulic oil to flow through check valve 107-2 into the two rod chambers, pushing the two single-rod bidirectional cylinders 110 downwards. In the connected state, the throttle valve 107-1 has flow resistance, causing hydraulic oil to flow into the rodless chamber through the check valve 1, pushing the single-rod double-acting cylinder 110 upward. At the same time, the hydraulic oil in both rod chambers converges and flows towards the working port A7 of the throttle valve 107-2 and the check valve 2. Since the check valve 2 is in the cut-off state, the hydraulic oil flows from the working port A7 and working port A4 of the throttle valve 107-2 to the working port A1, resulting in adjustable resistance during the hydraulic oil return process, thereby controlling the stable rise of the single-rod double-acting cylinder 110 and the adjustable rise speed.
[0041] Furthermore, this embodiment also includes a hydraulic pump 103 connected to the oil tank 101, a motor 102 driving the hydraulic pump 103, and a controller 112 controlling the motor 102. The oil outlet of the hydraulic pump 103 is connected to the oil inlet P1 of all the directional valves 106, and the oil return port T1 of the directional valves 106 is connected to the oil tank 101.
[0042] Specifically, the controller 112 controls the motor 102 to rotate, and the motor 102 drives the hydraulic pump 103 to draw hydraulic oil from the oil tank 101 and send it to the eight directional valves 106 along the lifting branch. Furthermore, the oil inlet P1 of each of the eight directional valves 106 is connected to the oil outlet of the hydraulic pump 103, and the oil return port T1 of each of the eight directional valves 106 is connected to the oil tank 101, so that all directional valves 106 are simultaneously filled with oil and simultaneously returned with oil, allowing the eight lifting mechanisms 200 to rise or fall simultaneously, improving their synchronization.
[0043] Furthermore, the lifting branch also includes: a pressure gauge 105 installed between the oil outlet of the hydraulic pump 103 and the oil inlet P1 of the reversing valve 106; and a return oil filter 111 installed on the branch between the return oil port T1 of the reversing valve 106 and the oil tank 101.
[0044] Specifically, the oil outlet of the hydraulic pump 103 and the oil inlet P1 of the reversing valve 106 are connected through a lifting branch. A branch is led out between them, which connects the pressure gauge 105, the buffer tube, and the bidirectional self-sealing quick connector in series. The buffer tube is a serpentine bend in the middle, which absorbs pressure pulses and impacts in the lifting branch, preventing instantaneous high pressure from directly impacting the spring tube inside the pressure gauge 105, thereby extending the service life of the pressure gauge 105 and improving the stability of the reading. Secondly, the bidirectional self-sealing quick connector includes two one-way check valves and a detachable connector, which allows the buffer tube to be quickly connected to or disconnected from the lifting branch without tools. When the connector is disconnected, the valve cores of the two one-way check valves automatically close under the action of the spring, preventing hydraulic oil from leaking out of the lifting branch and preventing external air from entering the system. Secondly, the return oil filter 111 is directly installed on the cover plate of the oil tank 101. Before the oil flowing out of the return oil port T1 of the reversing valve 106 returns to the oil tank 101, the return oil filter 111 filters out contaminants such as metal particles generated by component wear, keeps the hydraulic oil and the oil tank 101 clean, avoids contamination circulation, and improves system reliability.
[0045] like Figure 3 As shown, it also includes several adjustable height mechanical limiters 113. The mechanical limiters 113 form the highest point of the single lifting mechanism 200. When the lifting mechanism 200 rises and contacts the mechanical limiters 113, the internal oil pressure of the lifting branch rises.
[0046] Specifically, the mechanical limit 113 can be a limit structure that is fixed by bolts and whose height is adjusted by bolts and nuts, or it can be a limit structure that is fixed by a slide rail and whose height is adjusted along the slide rail. In this embodiment, the mechanical limit 113 is preferably formed into a long groove plate to limit the vertical travel of the middle structure of the lifting mechanism 200, thereby adapting to various lifting heights of the lifting mechanism 200 in production. Secondly, the moving end of the lifting mechanism 200 moves upward under the push of the lifting branch until the lifting mechanism 200 is fixed at the highest point of the mechanical limit 113, so that the eight lifting mechanisms 200 rise independently to the eight mechanical limit 113s respectively. The height of the eight mechanical limit 113s is the same, so that the top of the eight lifting mechanisms 200s is finally at the same height, forming a horizontal plane. The oil tank 101 continuously injects oil into all rodless chambers to increase their internal oil pressure, so that the oil pressure index of the pressure gauge 105 of each lifting branch rises one after another. The oil inlet P2 and the oil return T2 of the overflow valve 104 are connected until the oil inlet P2 and the oil return T2 of all overflow valves 104 are connected.
[0047] Example 2
[0048] like Figure 2As shown, this embodiment 2 is a lifting device, which includes: the hydraulic synchronous flow control system of embodiment 1. The hydraulic synchronous flow control system is applied to several lifting mechanisms 200 to unify the height of the highest lifting point of the lifting mechanism 200.
[0049] Specifically, the hydraulic synchronous flow control system simultaneously injects hydraulic oil into eight lifting mechanisms 200 and simultaneously changes eight directional valves 106 to enable all eight lifting mechanisms 200 to begin rising or falling simultaneously. Secondly, during the rising process, each lifting mechanism 200 contacts the mechanical limit switch 113, achieving a consistent final height. Furthermore, the lifting device can incorporate multiple lifting structures of the same structure, along with corresponding lifting and return branches, thereby enabling more lifting mechanisms 200 to achieve a consistent final height. This ensures low-cost and highly reliable lifting performance while increasing its load capacity.
[0050] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
[0051] The technologies, shapes, and structures not described in detail in this utility model are all known technologies.
Claims
1. A hydraulic synchronization flow control system applied to a multi-jacking mechanism, comprising an oil tank (101), characterized in that, Also comprising: a plurality of lifting branches in communication with the oil tank (101), the lifting branch being a hydraulic oil circuit formed by a single reversing valve (106), a plurality of synchronous motors (109) and a plurality of single-rod double-action oil cylinders (110) to respectively drive a plurality of structurally identical lifting mechanisms (200) to lift; a plurality of oil inlet ports arranged in a return branch between the oil tank (101) and the reversing valve (106), the oil outlet port of the return branch being in communication with the oil tank (101), the return branch being a hydraulic circuit formed by an overflow valve (104); When the internal oil pressure of the lifting branch applied to a single lifting mechanism (200) is greater than a preset oil pressure, the return branch of the corresponding lifting mechanism (200) is connected to balance the internal oil pressure of the lifting branch.
2. The hydraulic synchronous flow control system of claim 1, wherein: The overflow valve (104) forms an oil inlet port P2 in communication with the oil tank (101) and an oil outlet port T2 in communication with the oil tank (101); The preset oil pressure corresponds to the internal spring pressure of the overflow valve (104), and when the internal oil pressure of the lifting branch is greater than the internal spring pressure, the oil inlet port P2 and the oil outlet port T2 are connected.
3. The hydraulic synchronous flow control system of claim 1, wherein: The reversing valve (106) is a three-position four-way electromagnetic valve.
4. The hydraulic synchronous flow control system of claim 1, wherein: The single-rod double-action oil cylinder (110) forms a rod cavity connected to the lifting mechanism (200) and a rodless cavity away from the lifting mechanism (200); The lifting branch further comprises a balance valve (108) arranged in the communication oil circuit between the synchronous motor (109) and the single-rod double-action oil cylinder (110); The load port A3 of the balance valve (108) is in communication with the rodless cavity of the single-rod double-action oil cylinder (110), and the oil outlet port B3 of the balance valve (108) is in communication with the oil tank (101).
5. The hydraulic synchronous flow control system of claim 4, wherein: The lifting branch further comprises two throttle valves (107); The working oil port A4 of the throttle valve (107) is connected to the working oil port A1 of the reversing valve (106), the working oil port A5 of the throttle valve (107) is connected to the rod cavity of all single-rod double-action oil cylinders (110), the working oil port A6 of the throttle valve (107) is connected to the working oil port B1 of the reversing valve (106), and the working oil port A7 of the throttle valve (107) is connected to the working oil port of all synchronous motors (109).
6. The hydraulic synchronous flow control system of claim 1, wherein, Also comprising a hydraulic pump (103) in communication with the oil tank (101), a motor (102) driving the hydraulic pump (103) and a controller (112) controlling the motor (102), the oil outlet port of the hydraulic pump (103) is connected to the oil inlet port P1 of all reversing valves (106), and the oil return port T1 of the reversing valve (106) is connected to the same oil tank (101).
7. The hydraulic synchronous flow control system of claim 6, wherein: The lifting branch further comprises: a pressure gauge (105) mounted between the oil outlet port of the hydraulic pump (103) and the oil inlet port P1 of the reversing valve (106); and an oil return filter (111) mounted on the branch between the oil return port T1 of the reversing valve (106) and the oil tank (101).
8. The hydraulic synchronous flow control system of claim 1, wherein, Also included are several height-adjustable mechanical stops (113) that form the uppermost point of ascent of a single set of the jacking mechanisms (200), and the internal hydraulic pressure of the lifting branch rises when the jacking mechanisms (200) ascend to contact the mechanical stops (113).
9. A jacking device, characterized in that Comprise: The hydraulic synchronous flow control system as claimed in any one of claims 1 to 8 is applied to several of the jacking mechanisms (200) to unify the height of the uppermost point of ascent of the jacking mechanisms (200).