Unbalance load controllable multi-point support system

Abstract

The unbalanced load controllable multi-point support system comprises a plurality of single-cylinder jacks, the single-cylinder jacks are sequentially communicated through branch oil pipes, and the single-cylinder jacks or the branch oil pipes are communicated with a main oil pipe; a bidirectional pressure difference control valve is arranged on the branch oil pipe between the two single-cylinder jacks which are communicated with each other; the two-way differential pressure control valve comprises three working modes: a complete open circuit mode, a complete closed circuit mode and a differential pressure control mode. According to the multi-point support system, the single-cylinder jacks are connected in series through the branch oil pipes to form a closed loop, the two-way pressure difference control valves are arranged on the branch oil pipes between the single-cylinder jacks, three working modes of the two-way pressure difference control valves can enable the single-cylinder jacks to provide three different supporting types, and the supporting requirement is met; especially in a complete open circuit mode and a differential pressure control mode, cooperative work of the single-cylinder jacks can be achieved, and safety risks caused by the fact that the pressure of one or some single-cylinder jacks is too large during unbalance loading are prevented.

Description

Technical Field

[0001] The invention relates to a multi-point support system with controllable eccentric load, belonging to the field of hydraulic cylinder control. Background Art

[0002] The jacking method is a commonly used construction method in the field of bridge construction. It can transform operations in the river channel into river bank operations, expand the working surface and reduce construction risks. The jacking construction method pre-erects temporary piers in the river channel and arranges crawlers on the top of the piers to complete the subsequent jacking and pushing steps. The temporary piers provide necessary support for the bridge under construction. Before the bridge system conversion is completed, the temporary piers bear the deadweight of the bridge and the construction load. Therefore, ensuring the safety of the temporary piers is the most important part of the construction process.

[0003] Conventional temporary piers are generally composed of multiple piers to form a lattice pier. Transfer beams are set up on the top of the piers along the longitudinal and transverse directions of the bridge. The deadweight of the bridge is transferred to the piers through multiple support points from the transfer beams. Due to the deadweight of the bridge and the subsequent construction loads, the bridge will inevitably deform during construction, resulting in uneven force on each pier in the support system. In the most unfavorable case, only a single pier in the pier system is stressed, and the rest of the supports are all lifted, and the piers are in danger of being overloaded and crushed. At present, the common practice to deal with bridge deformation is to manually pad and set flexible blocks to reduce the degree of eccentric loading of the piers to a certain extent. However, this practice is a pre-emptive prevention, and the actual pad thickness cannot be accurately calculated. Once the over-pad is completed, the eccentric loading in the subsequent construction will be uncontrollable and cannot be further adjusted. In addition, manual padding consumes a lot of manpower and time, and the construction efficiency is low. Summary of the invention

[0004] In view of the problem that there are safety risks due to eccentric loading of piers when the existing bridge construction adopts the jacking method, the present invention provides a multi-point support system method with controllable eccentric loading.

[0005] In order to solve the above technical problems, the present invention includes the following technical solutions:

[0006] A multi-point support system with controllable eccentric load includes a plurality of single-cylinder jacks, the single-cylinder jacks are connected in sequence through branch oil pipes, and the single-cylinder jacks or the branch oil pipes are connected to the main oil pipe; a two-way pressure difference control valve is arranged on the branch oil pipe between two interconnected single-cylinder jacks;

[0007] The bidirectional differential pressure control valve includes three working modes: fully open mode, fully closed mode and differential pressure control mode;

[0008] When all the two-way differential pressure control valves are in full open circuit mode, the branch oil pipes are connected, and all the single-cylinder jacks provide the same lifting force to achieve uniform loading and unloading;

[0009] When all the two-way differential pressure control valves are in full closed-circuit mode, the branch oil pipes are not connected, and each single-cylinder jack works independently;

[0010] When all the two-way pressure differential control valves are in the pressure differential control mode, if the pressure differential on both sides of the two-way pressure differential control valve exceeds the set pressure differential, the two-way pressure differential control valve opens to reduce the pressure differential on both sides, and the supporting force of each single-cylinder jack tends to be the same; if the pressure differential on both sides of the two-way pressure differential control valve is less than or equal to the set pressure differential, the two-way pressure differential control valve closes, and each single-cylinder jack works independently.

[0011] Further, the bidirectional differential pressure control valve includes two Y-type oil circuit bifurcations arranged in opposite directions, the Y-type oil circuit bifurcations include two forks, the forks of the two Y-type oil circuit bifurcations are connected through one-way valves respectively, and the one-way valves on the two forks are arranged in opposite directions;

[0012] The one-way valve has three working modes: fully open mode, fully closed mode and pressure difference control mode.

[0013] Further, the one-way valve includes a valve housing, a pressure difference adjustment nut and a spring expansion and contraction adjustment assembly;

[0014] The valve housing includes a pipeline, a circular arc section facing the outside of the pipeline is arranged on the pipeline wall on one side of the center line of the pipeline, and a hollow threaded connector facing the outside of the pipeline and an L-shaped end plate facing the inside of the pipeline are arranged on the other side; the cantilever end of the L-shaped end plate faces the circular arc section of the pipeline, is flush with the pipeline wall at the end of the circular arc section of the pipeline and is arranged at intervals to form an internal port; the threaded connector is staggered with the circular arc section, and the hollow part of the threaded connector matches the position of the internal port;

[0015] The differential pressure regulating nut is threadedly connected to the threaded connector;

[0016] The spring expansion and contraction adjustment component is arranged in the hollow part of the threaded connector, one end of which is fixed to the pressure differential adjustment nut, and the other end faces the internal port and can seal the internal port; rotating the pressure differential adjustment nut outward can make the end of the spring expansion and contraction adjustment component completely separate from the internal port, and the one-way valve is in a fully open-circuit mode at this time; rotating the pressure differential adjustment nut inward can make the end of the spring expansion and contraction adjustment component tightly connected to the internal port, and when the force acting on the end of the spring expansion and contraction adjustment component is greater than the elastic force, it can push the spring expansion and contraction adjustment component to separate the end of the spring expansion and contraction adjustment component from the internal port, and the one-way valve is in a pressure differential control mode; rotating the pressure differential adjustment nut inward can make the end of the spring expansion and contraction adjustment component tightly connected to the internal port, and make the spring lose its expansion and contraction adjustment function, and the one-way valve is in a fully closed-circuit mode at this time.

[0017] Furthermore, the spring expansion and contraction adjustment assembly includes a buckle cap, a spring, a boss body and a sealing rubber ring;

[0018] The buckle cap is arranged in the pressure differential adjusting nut, one end of the buckle cap is fixed to the pressure differential adjusting nut, and the other end is provided with a T-slot, one end of the boss body is embedded in the T-slot, and can move axially along the T-slot in the T-slot; a sealing rubber ring is arranged at the other end of the boss body, and the sealing rubber ring can seal the internal port; a spring is arranged between the boss body and the buckle cap, and the spring elastic force has a tendency to make the boss body move toward the internal port.

[0019] Furthermore, the boss body includes a boss and a flat head nut, and the boss and the flat head nut are connected by threads.

[0020] Furthermore, the buckle cap includes two semicircular bodies which are spliced ​​and buckled, and the two semicircular bodies are tightened by bolts;

[0021] A T-shaped groove is arranged on the splicing end of the semicircular body, and the T-shaped grooves of the two semicircular bodies are spliced ​​to form a T-shaped groove.

[0022] Furthermore, a cushion block is arranged under the single-cylinder jack, and the size of the cushion block is larger than the end face size of the jack.

[0023] Furthermore, the single-cylinder jack includes an oil cylinder having three channels, and quick connectors are provided at the channels, two of which are respectively connected to branch oil pipes and serve as oil inlets and outlets respectively, and the quick connector of the third channel is closed or connected to the main oil pipe.

[0024] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: the multi-point support system with controllable eccentric load provided by the present invention forms a closed loop by connecting multiple single-cylinder jacks in series through branch oil pipes, and a two-way pressure differential control valve is arranged on the branch oil pipes between the single-cylinder jacks. The two-way pressure differential control valve includes three working modes: a fully open circuit mode, a fully closed circuit mode and a pressure differential control mode. The single-cylinder jacks can provide three different types of support to meet the support needs, especially in the fully open circuit mode and the pressure differential control mode. The single-cylinder jacks can work in coordination to prevent excessive pressure on one or some single-cylinder jacks when eccentric load occurs, causing safety risks. After the early debugging of the multi-point support system with controllable eccentric load provided by the present invention is completed, no power input is required in the later application process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of a multi-point support system in one embodiment of the present invention applied to bridge jacking construction;

[0026] Figure 2 It is a structural schematic diagram of a multi-point support system in one embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of a bidirectional differential pressure control valve in one embodiment of the present invention;

[0028] Figure 4 is a schematic diagram of a one-way valve in one embodiment of the present invention;

[0029] Figure 5 is a schematic diagram of a boss body in one embodiment of the present invention;

[0030] Figure 6 Schematic diagram of a buckle cap in one embodiment of the present invention.

[0031] The numbers in the figure are as follows:

[0032] 1- pier; 2- first transfer beam; 3- second transfer beam; 4- push bridge;

[0033] 10-multi-point support system; 11-jack; 12-branch oil pipe; 13-main oil pipe; 14-bidirectional differential pressure control valve; 15-pad;

[0034] 20-Y-type oil circuit splitter; 21-main circuit; 22-fork circuit; 23-quick connector;

[0035] 30- one-way valve; 31- valve housing; 311- pipe; 312- arc segment; 313- threaded connector; 314- L-shaped end plate; 315- internal port; 32- differential pressure adjustment nut; 33- spring expansion adjustment assembly; 331- buckle cap; 332- boss body; 3321- boss; 3322- T-nut; 333- spring; 334- sealing rubber ring. DETAILED DESCRIPTION

[0036] The following is a further detailed description of a multi-point support system with controllable eccentric load provided by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer in conjunction with the following description. It should be noted that the accompanying drawings are in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0037] This embodiment takes the bridge jacking construction as an example to introduce the multi-point support system with controllable eccentric load. Of course, the controllable multi-point support system in this embodiment can also be used in other situations where it is necessary to provide familiar support and there may be uneven loads to eliminate the influence of uneven loads. Figure 1As shown, the piers in the bridge jacking construction include a plurality of temporary column piers 1, and the column piers 1 are connected to each other by horizontal connecting members, thereby forming an integral lattice pier system, and the horizontal connecting members include a first transfer beam 2 directly in contact with the pier and a second transfer beam 3 placed on the first transfer beam 2. The first transfer beam and the second transfer beam are generally double-piece I-beam steel, the first transfer beam is reliably connected to the column pier, and the second transfer beam is fastened to the first transfer beam by high-strength bolts. The multi-point support system 10 with controllable eccentric load provided in this embodiment is arranged between the second transfer beam 3 and the jacking bridge 4, and the load of the jacking bridge 4 is transferred to the second transfer beam 3.

[0038] Combination Figure 1 and Figure 2 As shown, the multi-point support system 10 with controllable eccentric load includes a plurality of single-cylinder jacks 11, which are connected in sequence through branch oil pipes 12. An interface is provided on the single-cylinder jack 11 or the branch oil pipe 12, which is connected to the main oil pipe 13 through the interface. A two-way pressure differential control valve 14 is provided on the branch oil pipe 12 between two interconnected single-cylinder jacks 11. The two-way pressure differential control valve includes three working modes: a fully open mode, a fully closed mode and a pressure differential control mode. When all the two-way pressure differential control valves are in the fully open mode, the branch oil pipes are connected, and all the single-cylinder jacks provide the same lifting force to achieve uniform loading and unloading. When all the two-way pressure differential control valves are in the fully closed mode, the branch oil pipes are not connected, and each single-cylinder jack works independently. When all the two-way pressure differential control valves are in the pressure differential control mode, if the pressure differential on both sides of the two-way pressure differential control valve exceeds the set pressure differential, the two-way pressure differential control valve opens to reduce the pressure differential on both sides, and the supporting force of each single-cylinder jack tends to be the same; if the pressure differential on both sides of the two-way pressure differential control valve is less than or equal to the set pressure differential, the two-way pressure differential control valve closes, and each single-cylinder jack works independently.

[0039] When the multi-point bearing system with controllable eccentric load is applied to bridge jacking construction, after the jacking is completed and the bridge deck construction phase begins, the bridge may be deformed due to the construction load, causing eccentric load on the piers. To avoid this unfavorable situation, all the two-way differential pressure control valves can be in a completely open-circuit mode, and the forces of each jack are the same. At this time, multiple piers are approximately evenly loaded, and the bearing system has no rotational constraints on the bridge. After the jacking is completed and the elevation adjustment is completed, in order to fix the linearity of the bridge, all the two-way differential pressure control valves can be in a completely closed-circuit state, and each jack works independently, which can achieve the same effect as the traditional pier system. If the fully open circuit mode is adopted, the load change of the jacking bridge will cause the load of the single-cylinder jack to be readjusted. Too frequent adjustment of the single-cylinder jack is not conducive to the stability of the jacking bridge. When the fully open circuit mode is adopted, excessive eccentric load may affect the construction safety. When it is necessary to comprehensively consider the stability of the jacking bridge and the safety of large eccentric load, all the two-way pressure differential control valves can be put into the pressure differential control mode. Each jack can withstand a certain eccentric load effect. When the eccentric load effect is not large, the support system realizes the characteristics of a nearly rigid support. When the eccentric load effect is large, the two-way pressure differential control valve is opened, and the internal force of the support system is redistributed to reduce the eccentric load effect.

[0040] In a specific embodiment, in combination Figures 1 to 3 As shown, the bidirectional differential pressure control valve 14 includes two Y-type oil circuit bifurcations 20 arranged in opposite directions, the Y-type oil circuit bifurcations 20 includes a main circuit 21 and two bifurcations 22, and the bifurcations 22 of the two Y-type oil circuit bifurcations 20 are respectively connected through a one-way valve 30. The one-way valve 30 has three working modes, namely: a fully open circuit mode, a fully closed circuit mode and a differential pressure control mode. When the one-way valve is in the fully open circuit mode, the one-way valve is conductive; when the one-way valve is in the fully closed circuit mode, the one-way valve is not conductive; when the one-way valve is in the differential pressure control mode, when the differential pressure on both sides of the one-way valve exceeds the set differential pressure, the one-way valve is conductive to reduce the differential pressure on both sides of the one-way valve; when the differential pressure on both sides of the one-way valve is less than or equal to the set differential pressure, the one-way valve is closed and the one-way valve is not conductive. When the two check valves of the bidirectional differential pressure control valve are in the full open mode, full closed mode and differential pressure control mode at the same time, they correspond to the full open mode, full closed mode and differential pressure control mode of the bidirectional differential pressure control valve respectively. A quick connector 23 is provided at the end of the main circuit of the Y-type oil circuit splitter 20 to facilitate the quick connection of the bidirectional differential pressure control valve 14 with the branch oil pipe 12.

[0041] In a specific embodiment, in combination Figures 1 to 4As shown, the one-way valve 30 includes an integrated valve housing 31, a pressure difference adjustment nut 32 and a spring expansion and contraction adjustment assembly 33. The integrated valve housing 31 includes a pipe 311, and a circular arc section 312 facing the outside of the pipe is arranged on the pipe wall on one side of the center line of the pipe 311, and a hollow threaded connector 313 facing the outside of the pipe and an L-shaped end plate 314 facing the inside of the pipe are arranged on the other side. The threaded connector 313 is staggered with the circular arc section 312. One end of the L-shaped end plate 314 is vertically arranged with the inner wall of the pipe and flush with the inner wall of the threaded connector 313; the other end of the L-shaped end plate is used as a cantilever end, facing the circular arc section 312 of the pipe, and is flush with the inner wall of the pipe at the end of the circular arc section of the pipe and is arranged at intervals to form an internal port 315. The pressure differential adjustment nut 32 is threadedly connected to the threaded connector 313. The spring expansion and contraction adjustment assembly 33 is arranged in the hollow part of the threaded connector 313. One end is fixed to the pressure differential adjustment nut 32, and the other end faces the internal port 315 and can seal the internal port 315. By rotating the pressure differential adjustment nut 32, the distance between the spring expansion and contraction adjustment assembly 33 and the internal port 315 can be adjusted. Rotating the pressure differential adjusting nut outward can completely separate the end of the spring expansion and contraction adjusting assembly from the internal port, so that the one-way valve is in a fully open-circuit mode; rotating the pressure differential adjusting nut inward can make the end of the spring expansion and contraction adjusting assembly tightly connected to the internal port, and when the force of the hydraulic oil applied to the end of the spring expansion and contraction adjusting assembly is greater than the elastic force, the spring expansion and contraction adjusting assembly can be pushed to contract, so that the end of the spring expansion and contraction adjusting assembly is separated from the internal port. When the force of the hydraulic oil is less than the spring elastic force, the spring elastic force pushes the spring expansion and contraction adjusting assembly to be tightly connected to the internal port. In this state, the one-way valve is in a pressure differential control mode; continuing to rotate the pressure differential adjusting nut inward can make the end of the spring expansion and contraction adjusting assembly tightly connected to the internal port, and the spring of the spring expansion and contraction adjusting assembly loses its expansion and contraction adjustment function, and the one-way valve is in a fully closed-circuit mode.

[0042] In a specific embodiment, in combination Figures 1 to 4 As shown, the spring expansion and contraction adjustment assembly 33 includes a buckle cap 331, a boss body 332, a spring 333 and a sealing rubber ring 334. The buckle cap 331 is arranged in the differential pressure adjustment nut 32, one end of the buckle cap 331 is fixed to the differential pressure adjustment nut 32, and the other end is provided with a T-slot, one end of the boss body extends into the T-slot, the groove depth of the T-slot along the axial direction is greater than the thickness of the embedded end of the boss body, and the boss body can move in the T-slot along the axial direction of the T-slot; the other end of the boss body 332 is provided with a sealing rubber ring 334, and the sealing rubber ring 334 can seal the internal port 315; the boss body 332 and the buckle cap 32 are provided with a spring 333, and the spring elastic force has a tendency to move the boss body toward the internal port.

[0043] In a specific embodiment, in combination Figures 1 to 5As shown, the boss body 332 includes a boss 3321 and a flat nut 3322, and the boss and the flat nut are connected by threads. When assembling, the spring 333 is first sleeved on the boss 3321, and then the flat nut 3322 is tightened.

[0044] In a specific embodiment, in combination Figures 1 to 6 As shown, the buckle cap 331 includes two semicircular bodies 3311 that are spliced ​​and buckled. For example, the semicircular body 3311 can be tightened by pulling two bolts 3312. Of course, it can also be fixed by other forms such as clamps, mortise and tenon joints. A T-shaped groove is provided on the spliced ​​end of the semicircular body, and the T-shaped grooves of the two semicircular bodies are spliced ​​to form a T-shaped groove. A threaded hole 3313 can be provided at one end of the semicircular body facing the pressure differential adjustment nut, and the pressure differential adjustment nut 32 is bolted. The T-shaped groove includes an internal notch 3314 and a notch 3315 at the end, and the diameter of the notch 3314 is larger than the diameter of the notch 3315. When the two semicircular bodies 3311 are buckled, the grooves match the groove positions, the notches match the notch positions, the T-shaped groove accommodates the end of the boss body, and the notch accommodates the smaller diameter middle part of the boss body adjacent to the end. Specifically, the end of the flat head nut 3322 is located in the T-slot, the thickness of the end of the flat head nut 3322 is smaller than the depth of the T-slot, and the end of the flat head nut 3322 can move in the T-slot along the direction of the T-slot axis.

[0045] In a specific embodiment, in combination Figure 1 and Figure 2 As shown, a pad 15 is provided under the single-cylinder jack 11. The pad 15 can be made of a steel plate. The size of the pad is larger than the end face size of the jack, which can better transmit the force of the jack to the lower structure, and the pad can be more conveniently fixedly connected to the lower structure by bolts.

[0046] In a specific embodiment, the single-cylinder jack includes an oil cylinder, which has three channels, and quick connectors are provided at the channels, wherein two quick connectors are respectively connected to branch oil pipes, serving as oil inlets and oil outlets, respectively, and the quick connector of the third channel is closed or connected to the main oil pipe. When the quick connector of the third channel is connected to the main oil pipe, the hydraulic oil in the main oil pipe enters the hydraulic jack through the channel, and can enter the branch oil pipe through the other two quick connectors, so that the oil circuit is closed.

[0047] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A multi-point support system with controllable eccentric load, characterized in that: It includes a plurality of single-cylinder jacks, which are connected in sequence through branch oil pipes, and the single-cylinder jacks or the branch oil pipes are connected to the main oil pipe; a two-way pressure difference control valve is arranged on the branch oil pipe between two interconnected single-cylinder jacks; The bidirectional differential pressure control valve includes three working modes: fully open mode, fully closed mode and differential pressure control mode; When all the two-way differential pressure control valves are in full open circuit mode, the branch oil pipes are connected, and all the single-cylinder jacks provide the same lifting force to achieve uniform loading and unloading; When all the two-way differential pressure control valves are in full closed-circuit mode, the branch oil pipes are not connected, and each single-cylinder jack works independently; When all the two-way pressure differential control valves are in the pressure differential control mode, if the pressure differential on both sides of the two-way pressure differential control valve exceeds the set pressure differential, the two-way pressure differential control valve opens to reduce the pressure differential on both sides, and the supporting force of each single-cylinder jack tends to be the same; if the pressure differential on both sides of the two-way pressure differential control valve is less than or equal to the set pressure differential, the two-way pressure differential control valve closes, and each single-cylinder jack works independently.

2. The multi-point support system with controllable eccentric load as claimed in claim 1, characterized in that: The bidirectional differential pressure control valve comprises two Y-type oil circuit bifurcations arranged in opposite directions, the Y-type oil circuit bifurcations comprise two forks, the forks of the two Y-type oil circuit bifurcations are respectively connected through a one-way valve, and the one-way valves on the two forks are arranged in opposite directions; The one-way valve has three working modes: fully open mode, fully closed mode and pressure difference control mode.

3. The multi-point support system with controllable eccentric load as claimed in claim 1, characterized in that: The one-way valve includes a valve housing, a pressure difference adjustment nut and a spring expansion and contraction adjustment assembly; The valve housing includes a pipeline, a circular arc section facing the outside of the pipeline is arranged on the pipeline wall on one side of the center line of the pipeline, and a hollow threaded connector facing the outside of the pipeline and an L-shaped end plate facing the inside of the pipeline are arranged on the other side; the cantilever end of the L-shaped end plate faces the circular arc section of the pipeline, is flush with the pipeline wall at the end of the circular arc section of the pipeline and is arranged at intervals to form an internal port; the threaded connector is staggered with the circular arc section, and the hollow part of the threaded connector matches the position of the internal port; The differential pressure regulating nut is threadedly connected to the threaded connector; The spring expansion and contraction adjustment component is arranged in the hollow part of the threaded connector, one end of which is fixed to the pressure differential adjustment nut, and the other end faces the internal port and can seal the internal port; rotating the pressure differential adjustment nut outward can make the end of the spring expansion and contraction adjustment component completely separate from the internal port, and the one-way valve is in a fully open-circuit mode at this time; rotating the pressure differential adjustment nut inward can make the end of the spring expansion and contraction adjustment component tightly connected to the internal port, and when the force acting on the end of the spring expansion and contraction adjustment component is greater than the elastic force, it can push the spring expansion and contraction adjustment component to separate the end of the spring expansion and contraction adjustment component from the internal port, and the one-way valve is in a pressure differential control mode; rotating the pressure differential adjustment nut inward can make the end of the spring expansion and contraction adjustment component tightly connected to the internal port, and make the spring lose its expansion and contraction adjustment function, and the one-way valve is in a fully closed-circuit mode at this time.

4. The multi-point support system with controllable eccentric load as claimed in claim 3, characterized in that: The spring expansion and contraction adjustment assembly comprises a buckle cap, a spring, a boss body and a sealing rubber ring; The buckle cap is arranged in the pressure differential adjusting nut, one end of the buckle cap is fixed to the pressure differential adjusting nut, and the other end is provided with a T-slot, one end of the boss body is embedded in the T-slot, and can move axially along the T-slot in the T-slot; a sealing rubber ring is arranged at the other end of the boss body, and the sealing rubber ring can seal the internal port; a spring is arranged between the boss body and the buckle cap, and the spring elastic force has a tendency to make the boss body move toward the internal port.

5. The multi-point support system with controllable eccentric load as claimed in claim 4, characterized in that: The boss body comprises a boss and a flat head nut, and the boss and the flat head nut are connected through threads.

6. The multi-point support system with controllable eccentric load as claimed in claim 4, characterized in that: The buckle cap comprises two semicircular bodies which are spliced ​​and buckled, and the two semicircular bodies are tightened by bolts; A T-shaped groove is arranged on the splicing end of the semicircular body, and the T-shaped grooves of the two semicircular bodies are spliced ​​to form a T-shaped groove.

7. The multi-point support system with controllable eccentric load as claimed in claim 1, characterized in that: A cushion block is arranged under the single-cylinder jack, and the size of the cushion block is larger than the end face size of the jack.

8. The multi-point support system with controllable eccentric load as claimed in claim 1, characterized in that: The single-cylinder jack includes an oil cylinder with three channels. Quick connectors are provided at the channels, two of which are connected to branch oil pipes respectively and serve as oil inlet and outlet respectively. The quick connector of the third channel is closed or connected to the main oil pipe.

Images