阅读说明：本技术 一种四边形连杆机构 (Quadrilateral linkage mechanism ) 是由 杨翔 何清华 朱建新 曾素 于 2019-09-24 设计创作，主要内容包括：本发明公开了一种四边形连杆机构,包括依次首尾活动连接而形成四边形的第一连杆、上连杆、第二连杆和下连杆；上连杆和下连杆平行设置,第一连杆和第二连杆关于上连杆的中垂线呈对称分布；下连杆包括相连的第一平推缸和第二平推缸,第一平推缸和第二平推缸关于上连杆的中垂线呈对称分布；平推缸与相应的连杆活动连接；第一平推缸和第二平推缸均为双活塞杆压力缸,各平推缸的两活塞杆直径相同；第一平推缸和第二平推缸相对的活塞杆可相抵或分离。由此,可确保两个平推缸的活塞杆不管是伸出还是缩回其位移始终是相等的。通压力系统推动平推缸收缩或伸出,即可带动第一连杆和第二连杆无级同步等角度张开或者收拢。(The invention discloses a quadrilateral connecting rod mechanism, which comprises a first connecting rod, an upper connecting rod, a second connecting rod and a lower connecting rod which are sequentially movably connected end to form a quadrilateral; the upper connecting rod and the lower connecting rod are arranged in parallel, and the first connecting rod and the second connecting rod are symmetrically distributed relative to a perpendicular bisector of the upper connecting rod; the lower connecting rod comprises a first flat pushing cylinder and a second flat pushing cylinder which are connected, and the first flat pushing cylinder and the second flat pushing cylinder are symmetrically distributed around the perpendicular bisector of the upper connecting rod; the horizontal pushing cylinder is movably connected with the corresponding connecting rod; the first horizontal pushing cylinder and the second horizontal pushing cylinder are both double-piston-rod pressure cylinders, and the two piston rods of each horizontal pushing cylinder have the same diameter; the opposite piston rods of the first and second horizontal pushing cylinders can be pressed against or separated from each other. Thereby, it is ensured that the displacement of the piston rods of both thrust cylinders is always equal whether they are extended or retracted. The pressure system pushes the horizontal pushing cylinder to contract or extend out, and the first connecting rod and the second connecting rod can be driven to be synchronously opened or closed at equal angles in a stepless mode.)

1. A quadrilateral linkage mechanism comprises a first connecting rod (1), an upper connecting rod (4), a second connecting rod (9) and a lower connecting rod, wherein the first connecting rod (1), the upper connecting rod (4), the second connecting rod (9) and the lower connecting rod are sequentially and movably connected end to form a quadrilateral structure; the upper connecting rod (4) and the lower connecting rod are arranged in parallel, and the first connecting rod (1) and the second connecting rod (9) are symmetrically distributed relative to a perpendicular bisector of the upper connecting rod (4); it is characterized in that the preparation method is characterized in that,

the lower connecting rod comprises a first flat pushing cylinder (19) and a second flat pushing cylinder (11) which are connected, and the first flat pushing cylinder (19) and the second flat pushing cylinder (11) are symmetrically distributed around the perpendicular bisector of the upper connecting rod (4); the first horizontal pushing cylinder (19) is movably connected with the first connecting rod (1), and the second horizontal pushing cylinder (11) is movably connected with the second connecting rod (9); the first horizontal pushing cylinder (19) and the second horizontal pushing cylinder (11) are both double-piston-rod pressure cylinders, and the diameters of two piston rods of the horizontal pushing cylinders are the same; the opposite piston rods of the first flat pushing cylinder (19) and the second flat pushing cylinder (11) can be abutted or separated.

2. The quadrilateral linkage according to claim 1, characterized in that a first shape control cylinder (2) is movably connected between the first connecting rod (1) and the upper connecting rod (4), a second shape control cylinder (6) is movably connected between the second connecting rod (9) and the upper connecting rod (4), and the first shape control cylinder (2) and the second shape control cylinder (6) are symmetrically distributed about a perpendicular bisector of the upper connecting rod (4); the first shape control cylinder (2) and the second shape control cylinder (6) are both double-piston-rod pressure cylinders, and the two piston rods of each shape control cylinder have the same diameter.

3. The quadrilateral linkage according to claim 2, characterized in that the lower chamber of the first shape control cylinder (2) communicates with the upper chamber of the second shape control cylinder (6) through a first duct (20), the upper chamber of the first shape control cylinder (2) communicates with the lower chamber of the second shape control cylinder (6) through a second duct (21);

the cavity of the first flat pushing cylinder (19) far away from the second flat pushing cylinder (11) is an O1 cavity, and the cavity of the first flat pushing cylinder (19) near the second flat pushing cylinder (11) is an O2 cavity; the cavity of the second flat pushing cylinder (11) far away from the first flat pushing cylinder (19) is an O3 cavity, and the cavity of the second flat pushing cylinder (11) close to the first flat pushing cylinder (19) is an O4 cavity; the O1 cavity and the O4 cavity are respectively communicated with a pressure source, and the O2 cavity and the O3 cavity are communicated.

4. The quadrilateral linkage according to claim 3, wherein the O1 chamber and the O4 chamber are communicated with a pressure source through a first directional valve (151), the P port and the T port of the first directional valve (151) are respectively connected with the pressure source, the A port of the first directional valve (151) is communicated with an O1 chamber, and the B port of the first directional valve (151) is communicated with an O4 chamber.

5. The four-sided link mechanism of claim 4, wherein the port A of the first direction valve (151) communicates with a chamber O3, and a first cut-off valve (12) is provided on a pipe communicating the port A of the first direction valve (151) with a chamber O3;

a port B of the first reversing valve (151) is communicated with an O2 cavity, and a second stop valve (13) is arranged on a pipeline for communicating the port B of the first reversing valve (151) with an O2 cavity;

and a third stop valve (10) is arranged on a pipeline for communicating the O2 cavity with the O3 cavity.

6. The quadrilateral linkage according to claim 4 or 5, characterized in that the first duct (20) and the second duct (21) are in communication with a pressure source through a second directional valve (152), the P and T ports of the second directional valve (152) being respectively connected to the pressure source, the A port of the second directional valve (152) being in communication with the first duct (20), the B port of the second directional valve (152) being in communication with the second duct (21).

7. The quadrilateral linkage according to claim 6, characterized in that the upper and lower chambers of the first shape control cylinder (2) and the upper and lower chambers of the second shape control cylinder (6) are both in communication with a pressure source.

8. The quadrilateral linkage according to claim 7, wherein a first one-way valve (5) is arranged on the pipeline of the upper chamber of the first shape control cylinder (2) communicating with the pressure source, and a second one-way valve (3) is arranged on the pipeline of the lower chamber of the first shape control cylinder (2) communicating with the pressure source; and a third one-way valve (7) is arranged on a pipeline for communicating the upper cavity of the second shape control cylinder (6) with the pressure source, and a fourth one-way valve (8) is arranged on a pipeline for communicating the lower cavity of the second shape control cylinder (6) with the pressure source.

9. The quadrilateral linkage according to claim 8, characterized in that the first (5), second (3), third (7) and fourth (8) one-way valves are all in communication with a pressure source through a third duct (22); a shuttle valve group (17) is arranged on the third pipeline (22), the shuttle valve group (17) comprises a first shuttle valve (171), a second shuttle valve (172) and a third shuttle valve (173), an A port of the first shuttle valve (171) is communicated with the third pipeline (22), a P1 port of the first shuttle valve (171) is communicated with an A port of the second shuttle valve (172), and a P2 port of the first shuttle valve (171) is communicated with an A port of the third shuttle valve (173); the port P1 of the second shuttle valve (172) is communicated with the port A of the second reversing valve (152), and the port P2 of the second shuttle valve (172) is communicated with the port B of the second reversing valve (152); the port P1 of the third shuttle valve (173) is communicated with the port A of the first reversing valve (151), and the port P2 of the third shuttle valve (173) is communicated with the port B of the first reversing valve (151).

10. The quadrilateral linkage according to claim 6, characterized in that ports A and B of the first directional valve (151) are commonly connected to a first hydraulic lock (14) and ports A and B of the second directional valve (152) are commonly connected to a second hydraulic lock (16).

Technical Field

The invention relates to the technical field of link mechanisms, in particular to a quadrilateral link mechanism.

Background

In practical engineering practice, a four-bar linkage is often needed, which can be adjusted at equal angles to change the shape of a quadrangle, and can maintain the specific shape under a stressed state after being adjusted to a specific quadrangle shape. The existing scheme generally adopts pure mechanism connection, and as shown in fig. 1, the existing four-bar linkage mechanism is movably connected by a first connecting rod 1.1, an upper platform 1.3, a right connecting rod 1.5 and a bottom screw rod assembly 1.6 to form a quadrilateral structure. A left inclined strut screw component 1.2 is movably connected between the first connecting rod 1.1 and the upper platform 1.3, and a right inclined strut screw component 1.4 is movably connected between the right connecting rod 1.5 and the upper platform 1.3. The first connecting rod 1.1 and the right connecting rod 1.5 are required to be unfolded or folded at equal angles by adjusting the left inclined strut screw component 1.2, the right inclined strut screw component 1.4 and the bottom screw component 1.6 so as to adjust the shape of the required four connecting rods. This structure has the following disadvantages:

1) the lead screw is adjusted manually, so that the labor intensity is high and the efficiency is low.

2) Because the shape of the four connecting rods is manually adjusted, the operation error is large, and the left connecting rod or the right connecting rod is difficult to be opened or closed at equal angles strictly.

3) When the shape of the four-bar linkage is adjusted, the adjustment must be carried out in a no-load state;

4) due to the fact that errors exist in the length of the screw rod adjustment, and experience of people is different when the screw rod is screwed up manually, after the screw rod is adjusted, stress matching of structural parts is uneven.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a quadrilateral linkage mechanism which realizes automatic synchronous stable opening or closing of a left connecting rod and a right connecting rod under the working condition of mechanism load.

In order to solve the technical problems, the invention adopts the following technical scheme:

a quadrilateral linkage mechanism comprises a first connecting rod, an upper connecting rod, a second connecting rod and a lower connecting rod, wherein the first connecting rod, the upper connecting rod, the second connecting rod and the lower connecting rod are sequentially and movably connected end to form a quadrilateral; the upper connecting rod and the lower connecting rod are arranged in parallel, and the first connecting rod and the second connecting rod are symmetrically distributed around a perpendicular bisector of the upper connecting rod;

the lower connecting rod comprises a first flat pushing cylinder and a second flat pushing cylinder which are connected, and the first flat pushing cylinder and the second flat pushing cylinder are symmetrically distributed around the perpendicular bisector of the upper connecting rod; the first horizontal pushing cylinder is movably connected with the first connecting rod, and the second horizontal pushing cylinder is movably connected with the second connecting rod; the first horizontal pushing cylinder and the second horizontal pushing cylinder are both double-piston-rod pressure cylinders, and the two piston rods of each horizontal pushing cylinder have the same diameter; and the opposite piston rods of the first and second horizontal pushing cylinders can be abutted or separated.

Because the first horizontal pushing cylinder and the second horizontal pushing cylinder are double-acting oil cylinders, the cylinder diameter and the rod diameter of the first horizontal pushing cylinder and the rod diameter of the second horizontal pushing cylinder are equal, and the first horizontal pushing cylinder and the second horizontal pushing cylinder are connected in series, the displacement of the piston rods of the two horizontal pushing cylinders is always equal regardless of the extension or retraction of the piston rods of the two horizontal pushing cylinders. Thereby ensuring that the first connecting rod and the second connecting rod are synchronously and equiangularly adjusted to form the four-connecting-rod shape all the time.

The first horizontal pushing cylinder and the second horizontal pushing cylinder are pushed to contract or extend through a hydraulic system or a pneumatic system, and the first connecting rod and the second connecting rod can be driven to open or close at equal angles, so that the shape of the quadrilateral linkage mechanism can be adjusted in a stepless synchronous equal-angle loading mode. The screw rod support does not need to be adjusted manually in the adjusting process, the adjusting efficiency is greatly improved, and the labor intensity is reduced; and can be carried and adjusted, the adjustment precision is high.

As a further improvement of the above technical solution:

a first shape control cylinder is movably connected between the first connecting rod and the upper connecting rod, a second shape control cylinder is movably connected between the second connecting rod and the upper connecting rod, and the first shape control cylinder and the second shape control cylinder are symmetrically distributed around a perpendicular bisector of the upper connecting rod; the first shape control cylinder and the second shape control cylinder are both double-piston-rod pressure cylinders, and the two piston rods of each shape control cylinder are the same in diameter.

When the whole four-bar mechanism does not move and is in a static state, the first shape control cylinder and the second shape control cylinder are equivalent to two pure structure rod pieces to support the whole mechanism, and the strength and the bearing capacity of the mechanism are greatly improved.

When the four-bar mechanism is opened or closed, the first shape control cylinder and the second shape control cylinder can be controlled to synchronously act with the first pushing cylinder and the second pushing cylinder through the control of a hydraulic system or a pneumatic system, so that the opening or closing stability of the four-bar mechanism is improved. In addition, the first shape control cylinder and the second shape control cylinder are double-acting oil cylinders, and the cylinder diameter and the rod diameter of the first shape control cylinder and the second shape control cylinder are equal, so that the situation that the mechanism cannot move due to the pressure building of the shape control cylinders cannot exist in the process of adjusting the shape of the four-bar linkage.

For automatically controlling the first connecting rod and the second connecting rod to fold synchronously at equal angles:

the lower cavity of the first shape control cylinder is communicated with the upper cavity of the second shape control cylinder through a first pipeline, and the upper cavity of the first shape control cylinder is communicated with the lower cavity of the second shape control cylinder through a second pipeline;

a cavity of the first flat pushing cylinder, which is far away from the second flat pushing cylinder, is an O1 cavity, and a cavity of the first flat pushing cylinder, which is close to the second flat pushing cylinder, is an O2 cavity; a cavity of the second pushing cylinder, which is far away from the first pushing cylinder, is an O3 cavity, and a cavity of the second pushing cylinder, which is close to the first pushing cylinder, is an O4 cavity; the O1 cavity and the O4 cavity are respectively communicated with a pressure source, and the O2 cavity and the O3 cavity are communicated.

The O1 chamber and the O4 chamber are communicated with a pressure source through a first reversing valve, a P port and a T port of the first reversing valve are respectively connected with the pressure source, an A port of the first reversing valve is communicated with an O1 chamber, and a B port of the first reversing valve is communicated with an O4 chamber.

The working principle of the structure for synchronously folding or unfolding the first connecting rod and the second connecting rod at equal angles is as follows:

the pressure medium flows into the O1 chamber of the first thrust cylinder, pushing the piston rod of the first thrust cylinder towards the second thrust cylinder. The first connecting rod corresponding to the first horizontal pushing cylinder is drawn in under the driving of the piston rod of the first horizontal pushing cylinder, the piston rod of the first shape control cylinder corresponding to the first horizontal pushing cylinder is retracted under the driving of the first connecting rod, the volume of the upper cavity of the first shape control cylinder is reduced, and a pressure medium flows out through the first pipeline and finally flows into the lower cavity of the second shape control cylinder; the volume of the lower cavity of the second shape control cylinder is increased. When the piston rod of the first thrust cylinder moves towards the second thrust cylinder, the pressure medium in the cavity O2 of the first thrust cylinder can flow into the cavity O3 of the second thrust cylinder, and the piston rod of the second thrust cylinder is pushed to move towards the first thrust cylinder. The second connecting rod is synchronously folded under the driving of a piston rod of the second horizontal pushing cylinder; a piston rod of the second shape control cylinder retracts under the driving of the second connecting rod, the volume of an upper cavity of the second shape control cylinder is reduced, and pressure medium flows out through a second pipeline and finally flows into a lower cavity of the first shape control cylinder; the volume of the lower cavity of the second shape control cylinder is increased. The pressure medium in the cavity of the second flat pushing cylinder O4 flows out and flows back to the pressure source under the pushing of the piston rod. When the first connecting rod and the second connecting rod need to be unfolded synchronously at equal angles, the movement process is opposite to that described above.

Because the upper cavities and the lower cavities of the first shape control cylinder and the second shape control cylinder are mutually crossed and connected to form pressure interlocking, the whole mechanism can not incline and topple even if the cavities of the shape control cylinders are opened in the process of adjusting the shape of the four-bar linkage. The interlocking principle is as follows: assuming that the whole mechanism has a tendency of inclining towards the first shape control cylinder, the two mounting hinge points of the first shape control cylinder are shortened, namely the piston rod needs to retract, and the two mounting hinge points of the second shape control cylinder are lengthened, namely the piston rod needs to extend. The pressure medium in the upper cavity of the first shape control cylinder must flow to the lower cavity of the second shape control cylinder, and the pressure medium in the lower cavity of the second shape control cylinder must also flow to the upper cavity of the first shape control cylinder. When the whole mechanism has the tendency of inclining towards the direction of the second shape control cylinder, the working principle of inclining and inclining prevention is the same.

The first and second horizontal pushing cylinders are debugged and maintained, and the air in the first and second horizontal pushing cylinders and the pipeline is removed in the installation, debugging and maintenance processes of the mechanism:

the port A of the first reversing valve is communicated with the O3 cavity, and a first stop valve is arranged on a pipeline for communicating the port A of the first reversing valve with the O3 cavity;

a port B of the first reversing valve is communicated with an O2 cavity, and a second stop valve is arranged on a pipeline for communicating the port B of the first reversing valve with an O2 cavity;

and a third stop valve is arranged on a pipeline for communicating the O2 cavity with the O3 cavity.

The working principle of the first horizontal pushing cylinder and the second horizontal pushing cylinder which are debugged by the structure is as follows: the first reversing valve and the second stop valve work to control the piston rod of the first thrust cylinder to independently extend or retract; the first reversing valve and the first stop valve are electrified, and the piston rod of the second translation cylinder can be controlled to independently extend or retract; the first reversing valve, the first stop valve, the second stop valve and the third stop valve are all powered on, and pressure media can be controlled to flow through the first reversing valve, the first stop valve, the second stop valve, the third stop valve, the first thrust cylinder and the second thrust cylinder through pipelines; after the repeated movement of the flat push cylinder and the pressure medium flows through each pressure element, air in the flat push cylinder and the pipeline can be exhausted.

For debugging and maintaining the first shape control cylinder and the second shape control cylinder, the air in the first shape control cylinder, the second shape control cylinder and each pipeline is ensured to be removed in the installation, debugging and maintenance processes of the mechanism:

the first pipeline and the second pipeline are communicated with a pressure source through a second reversing valve, a port P and a port T of the second reversing valve are respectively connected with the pressure source, a port A of the second reversing valve is communicated with the first pipeline, and a port B of the second reversing valve is communicated with the second pipeline.

The working principle of debugging the first shape control cylinder and the second shape control cylinder by the structure is as follows: under the control of the second reversing valve, the whole four-bar linkage mechanism can incline towards the direction of the first shape control cylinder or incline towards the direction of the second shape control cylinder, and air in the pipeline and the shape control cylinder can be exhausted after repeated movement. When the shape control cylinder is maintained and replaced, the piston rod of the shape control cylinder can extend out and retract under the control of the second reversing valve, so that the shape control cylinder can be conveniently installed, and air in the shape control cylinder and a pipeline can be conveniently exhausted.

The upper cavity and the lower cavity of the first shape control cylinder and the upper cavity and the lower cavity of the second shape control cylinder are communicated with a pressure source, so that initial pressure media can be provided for the first shape control cylinder and the second shape control cylinder or the pressure media in the first shape control cylinder and the second shape control cylinder can be discharged during maintenance.

A first check valve is arranged on a pipeline for communicating the upper cavity of the first shape control cylinder with the pressure source, and a second check valve is arranged on a pipeline for communicating the lower cavity of the first shape control cylinder with the pressure source; and a third one-way valve is arranged on a pipeline for communicating the upper cavity of the second shape control cylinder with the pressure source, and a fourth one-way valve is arranged on a pipeline for communicating the lower cavity of the second shape control cylinder with the pressure source.

The first one-way valve, the second one-way valve, the third one-way valve and the fourth one-way valve are all communicated with a pressure source through a third pipeline; a shuttle valve group is arranged on the third pipeline and comprises a first shuttle valve, a second shuttle valve and a third shuttle valve, an A port of the first shuttle valve is communicated with the third pipeline, a P1 port of the first shuttle valve is communicated with an A port of the second shuttle valve, and a P2 port of the first shuttle valve is communicated with an A port of the third shuttle valve; the port P1 of the second shuttle valve is communicated with the port A of the second reversing valve, and the port P2 of the second shuttle valve is communicated with the port B of the second reversing valve; the P1 port of the third shuttle valve is communicated with the A port of the first reversing valve, and the P2 port of the third shuttle valve is communicated with the B port of the first reversing valve.

By designing the shuttle valve group, the pipeline of the reversing valve with higher pressure in the shuttle valve group can be taken to open each one-way valve, so that the pressure medium can flow into each cavity of the first shape control cylinder and the second shape control cylinder.

The pressure source mentioned in this application may be a hydraulic power system, and accordingly the pressure medium is preferably hydraulic oil. The pressure source may also be a pneumatic system.

When the pressure source is a hydraulic power system, the port A and the port B of the first reversing valve are connected with the first hydraulic lock together, and the port A and the port B of the second reversing valve are connected with the second hydraulic lock together.

Compared with the prior art, the invention has the advantages that:

the quadrilateral linkage mechanism can adjust the shape of the quadrilateral linkage mechanism in a stepless synchronous equal-angle loading manner through the hydraulic system, does not need to manually adjust the screw rod support in the adjusting process, can adjust in a loading manner, has high adjusting precision and simple structure, reduces the labor intensity, improves the labor efficiency, improves the shape precision of the four-linkage mechanism, and can enable all parts of the four-linkage mechanism to be stressed more uniformly.

Drawings

Fig. 1 is a schematic structural view of a prior art quadrilateral linkage mechanism.

Fig. 2 is a schematic structural view of the quadrilateral linkage mechanism of the invention.

Illustration of the drawings: 1. a first link; 2. a first shape control cylinder; 3. a second one-way valve; 4. an upper connecting rod; 5. a first check valve; 6. a second shape control cylinder; 7. a third check valve; 8. a fourth check valve; 9. a second link; 10. a third stop valve; 11. a second thrust cylinder; 12. a first shut-off valve; 13. a second stop valve; 14. a first hydraulic lock; 151. a first direction changing valve; 152. A second directional control valve; 16. a second hydraulic lock; 17. a shuttle valve group; 171. a first shuttle valve; 172. a second shuttle valve; 173. a third shuttle valve; 18. a coupling sleeve; 19. a first flat push cylinder; 20. A first conduit; 21. a second conduit; 22. A third conduit.

Detailed Description

The invention is further described below with reference to specific preferred embodiments, without thereby limiting the scope of protection of the invention.

Example 1:

as shown in fig. 2, the quadrilateral linkage mechanism of the present embodiment includes a first link 1, an upper link 4, a second link 9, a lower link, a first shape control cylinder 2, a second shape control cylinder 6, and a hydraulic control system. The first connecting rod 1, the upper connecting rod 4, the second connecting rod 9 and the lower connecting rod are sequentially movably connected end to form a quadrangle; the upper connecting rod 4 and the lower connecting rod are arranged in parallel, and the first connecting rod 1 and the second connecting rod 9 are symmetrically distributed about a perpendicular bisector of the upper connecting rod 4.

The lower connecting rod comprises a first flat pushing cylinder 19 and a second flat pushing cylinder 11 which are connected through a connecting sleeve 18, and the first flat pushing cylinder 19 and the second flat pushing cylinder 11 are symmetrically distributed around the perpendicular bisector of the upper connecting rod 4; the first horizontal pushing cylinder 19 is movably connected with the first connecting rod 1, and the second horizontal pushing cylinder 11 is movably connected with the second connecting rod 9; the first horizontal pushing cylinder 19 and the second horizontal pushing cylinder 11 are both double-piston-rod pressure cylinders, and the two piston rods of each horizontal pushing cylinder have the same diameter; the opposite piston rods of the first and second thrust cylinders 19 and 11 can be abutted or separated.

The first shape control cylinder 2 is movably connected between the first connecting rod 1 and the upper connecting rod 4, the second shape control cylinder 6 is movably connected between the second connecting rod 9 and the upper connecting rod 4, and the first shape control cylinder 2 and the second shape control cylinder 6 are symmetrically distributed about a perpendicular bisector of the upper connecting rod 4; the first shape control cylinder 2 and the second shape control cylinder 6 are both double-piston-rod pressure cylinders, and the two piston rods of each shape control cylinder have the same diameter.

The hydraulic control system comprises a hydraulic source, a first reversing valve 151, a second reversing valve 152, a first check valve 5, a second check valve 3, a third check valve 7, a fourth check valve 8, a shuttle valve group 17 and connecting pipelines between the hydraulic source and each cylinder.

The lower cavity of the first shape control cylinder 2 is communicated with the upper cavity of the second shape control cylinder 6 through a first pipeline 20, and the upper cavity of the first shape control cylinder 2 is communicated with the lower cavity of the second shape control cylinder 6 through a second pipeline 21.

A cavity of the first flat push cylinder 19 far away from the second flat push cylinder 11 is an O1 cavity, and a cavity of the first flat push cylinder 19 near the second flat push cylinder 11 is an O2 cavity; a cavity of the second pushing cylinder 11 far away from the first pushing cylinder 19 is an O3 cavity, and a cavity of the second pushing cylinder 11 near the first pushing cylinder 19 is an O4 cavity; the O1 cavity and the O4 cavity are respectively communicated with a hydraulic pressure source, and the O2 cavity and the O3 cavity are respectively communicated. The O1 chamber and the O4 chamber are communicated with a hydraulic source through the first direction valve 151, the P port and the T port of the first direction valve 151 are respectively connected with the hydraulic source, the a port of the first direction valve 151 is communicated with the O1 chamber, and the B port of the first direction valve 151 is communicated with the O4 chamber.

In this embodiment, the port a of the first direction valve 151 is communicated with the O3 cavity, and the first stop valve 12 is arranged on the pipeline communicating the port a of the first direction valve 151 with the O3 cavity; a port B of the first reversing valve 151 is communicated with an O2 cavity, and a second stop valve 13 is arranged on a pipeline for communicating the port B of the first reversing valve 151 with an O2 cavity; and a third stop valve 10 is arranged on a pipeline for communicating the O2 cavity with the O3 cavity.

The first pipeline 20 and the second pipeline 21 are communicated with a hydraulic source through a second direction changing valve 152, a port P and a port T of the second direction changing valve 152 are respectively connected with the hydraulic source, a port A of the second direction changing valve 152 is communicated with the first pipeline 20, and a port B of the second direction changing valve 152 is communicated with the second pipeline 21.

In this embodiment, the upper chamber and the lower chamber of the first shape control cylinder 2 and the upper chamber and the lower chamber of the second shape control cylinder 6 are both communicated with a hydraulic source.

A first check valve 5 is arranged on a pipeline for communicating the upper cavity of the first shape control cylinder 2 with a hydraulic source, and a second check valve 3 is arranged on a pipeline for communicating the lower cavity of the first shape control cylinder 2 with the hydraulic source; a third one-way valve 7 is arranged on a pipeline for communicating the upper cavity of the second shape control cylinder 6 with the hydraulic source, and a fourth one-way valve 8 is arranged on a pipeline for communicating the lower cavity of the second shape control cylinder 6 with the hydraulic source.

The first check valve 5, the second check valve 3, the third check valve 7 and the fourth check valve 8 are all communicated with a hydraulic source through a third pipeline 22; a shuttle valve group 17 is arranged on the third pipeline 22, the shuttle valve group 17 comprises a first shuttle valve 171, a second shuttle valve 172 and a third shuttle valve 173, a port A of the first shuttle valve 171 is communicated with the third pipeline 22, a port P1 of the first shuttle valve 171 is communicated with a port A of the second shuttle valve 172, and a port P2 of the first shuttle valve 171 is communicated with a port A of the third shuttle valve 173; the port P1 of the second shuttle valve 172 communicates with the port A of the second direction valve 152, and the port P2 of the second shuttle valve 172 communicates with the port B of the second direction valve 152; the port P1 of the third shuttle valve 173 communicates with the port a of the first direction valve 151, and the port P2 of the third shuttle valve 173 communicates with the port B of the first direction valve 151.

The ports a and B of the first switching valve 151 are commonly connected to the first hydraulic lock 14, and the ports a and B of the second switching valve 152 are commonly connected to the second hydraulic lock 16.

In this embodiment, the first direction valve 151 and the second direction valve 152 are both electromagnetic direction valves, and the first stop valve 12, the second stop valve 13, and the third stop valve 10 are all electromagnetic stop valves. In other schemes, the electromagnetic directional valve and the electromagnetic valve can be replaced by a hydraulic control valve, a manual or pneumatic directional valve and a pneumatic control valve.

The working principle of the equiangular synchronous folding or unfolding of the first connecting rod and the second connecting rod in the embodiment is as follows: when the first connecting rod 1 and the second connecting rod 9 need to be synchronously folded at equal angles, the first reversing valve 151 is controlled to be reversed to the lower position, and the electromagnetic stop valve 10 is controlled to be reversed to the upper position. The pressure oil entering from the port P flows into the left chamber (i.e., the O1 chamber) of the first thrust cylinder 19 via the first direction switching valve 151, and pushes the piston rod of the first thrust cylinder 19 to move rightward. Meanwhile, the pressure oil flows through the shuttle valve group 17 and then reaches the hydraulic control ports of the hydraulic control one-way valve 3, the hydraulic control one-way valve 5, the hydraulic control one-way valve 7 and the hydraulic control one-way valve 8, and the four hydraulic control one-way valves are opened, so that the hydraulic oil in the upper cavity of the first shape control cylinder 2 can flow out through the hydraulic control one-way valve 5. The first connecting rod 1 is folded under the drive of the piston rod of the first pushing cylinder 19, the piston rod of the first shape control cylinder 2 is retracted under the drive of the first connecting rod 1, the volume of the upper cavity of the first shape control cylinder 2 is reduced, hydraulic oil flows out through the hydraulic control one-way valve 5 and finally flows into the lower cavity of the second shape control cylinder 6; the volume of the lower cavity of the first shape control cylinder 2 is increased. When the piston rod of the first horizontal pushing cylinder 19 moves rightwards, because the electromagnetic stop valve 10 is switched to an upper position, the hydraulic oil in the right cavity of the first horizontal pushing cylinder 19 can flow into the second horizontal pushing cylinder 11 through the electromagnetic stop valve 10 to push the piston rod of the second horizontal pushing cylinder 11 to move leftwards. The second connecting rod 9 is synchronously folded under the driving of the piston rod of the second horizontal pushing cylinder 11; the piston rod of the second shape control cylinder 6 retracts under the driving of the second connecting rod 9, the volume of the upper cavity of the second shape control cylinder 6 is reduced, and hydraulic oil flows out through the hydraulic control one-way valve 7 and finally flows into the lower cavity of the first shape control cylinder 2; the volume of the lower chamber of the second form controlling cylinder 6 increases. The hydraulic oil in the left chamber of the second horizontal pushing cylinder 11 flows out under the pushing of the piston rod, flows through the first hydraulic lock 14 and the first reversing valve 151, reaches the T port, and flows back to the oil tank. When the first connecting rod 1 and the second connecting rod 9 need to be unfolded synchronously at equal angles, the movement process is opposite to the above process.

Because the first and second thrust cylinders 19 and 11 are double-acting cylinders, and the cylinder diameters and rod diameters thereof are equal, and the hydraulic connection is a series connection mode, the displacements of the piston rods of the two cylinders are always equal regardless of the extension or retraction. This finally ensures that the first connecting rod 1 and the second connecting rod 9 are synchronously and equiangularly adjusted to the shape of the four-connecting rod.

The first shape control cylinder 2 and the second shape control cylinder 6 are also double-acting oil cylinders, and the cylinder diameter and the rod diameter of the double-acting oil cylinders are equal. The upper cavity and the lower cavity of the first shape control cylinder 2 and the second shape control cylinder 6 are mutually connected in a cross way, when the piston rods of the first shape control cylinder 2 and the second shape control cylinder 6 extend out or retract simultaneously, hydraulic oil in the cavity at one side with the reduced volume due to extrusion in the oil cylinder flows to the cavity at one side with the increased volume of the oil cylinder at the opposite side. Because the first shape control cylinder 2 and the second shape control cylinder 6 are double-acting oil cylinders and the cylinder diameters and the rod diameters of the double-acting oil cylinders are equal, the condition that the mechanism cannot move due to the fact that the shape control cylinders are subjected to pressure holding in the process of adjusting the shape of the four-bar linkage is avoided.

Because the upper cavity and the lower cavity of the first shape control cylinder 2 and the second shape control cylinder 6 are mutually crossed and connected to form hydraulic interlocking, the whole mechanism can not incline and topple even if the hydraulic control one-way valve 3, the hydraulic control one-way valve 5, the hydraulic control one-way valve 7 and the hydraulic control one-way valve 8 are opened in the process of adjusting the shape of the four-bar linkage. The interlocking principle is as follows: assuming that the whole mechanism has a tendency of inclining towards the left, the two mounting hinge points of the first shape control cylinder 2 are shortened, namely, the piston rod needs to retract, and the two mounting hinge points of the right shape control cylinder 2 are lengthened, namely, the piston rod needs to extend. The result is that the hydraulic oil in the upper cavity of the first shape control cylinder 2 must flow to the lower cavity of the second shape control cylinder 6, and the hydraulic oil in the lower cavity of the second shape control cylinder 6 must also flow to the upper cavity of the first shape control cylinder 2, and because the hydraulic oil is incompressible, the hydraulic oil is always trapped in the cavity and the pipeline which are connected in a cross way, so that the first shape control cylinder 2 and the second shape control cylinder 6 together form a hydraulic support, and the whole mechanism is ensured not to incline and topple to the left. When the whole mechanism has the tendency of inclining towards the right, the working principle of preventing the inclining and the inclining is the same.

When the whole four-bar mechanism does not move and is in a static state, the hydraulic control one-way valve 3, the hydraulic control one-way valve 5, the hydraulic control one-way valve 7 and the hydraulic control one-way valve 8 are not opened, the first shape control cylinder 2 and the second shape control cylinder 6 are equivalent to two pure structure rod pieces for supporting the whole mechanism, and the strength and the bearing capacity of the mechanism are greatly improved.

The second reversing valve 152 and the second hydraulic lock 16 are connected with the first shape control cylinder 2 and the second shape control cylinder 6 through pipelines to form a debugging and maintaining system of the left and right shape control cylinders. The function of the device is mainly to remove air in the oil cylinders of the first shape control cylinder 2 and the second shape control cylinder 6 and the pipeline in the installation, debugging and maintenance processes of the mechanism. The working principle is as follows: under the control of the second direction changing valve 152, the whole four-bar linkage mechanism can incline to the left or the right, and air in the pipeline and the oil cylinder can be exhausted after repeated movement. When the oil cylinder is maintained and replaced, the piston rod of the shape control cylinder can extend and retract under the control of the second reversing valve 152, so that the oil cylinder is conveniently installed and air in the oil cylinder and a pipeline is conveniently exhausted.

The first reversing valve 151, the first hydraulic lock 14, the second stop valve 13, the first stop valve 12, the first thrust cylinder 19 and the second thrust cylinder 11 are connected through pipelines to form a debugging and maintenance system of the first thrust cylinder and the second thrust cylinder. The function of the device is mainly to remove air in the first and second thrust cylinders 19 and 11 and the pipeline in the process of installation, debugging and maintenance of the mechanism. The working principle is as follows: the first reversing valve 151 and the second stop valve 13 are electrified, and the piston rod of the first thrust cylinder 19 can be controlled to extend or retract independently; the first reversing valve 151 and the first stop valve 12 are electrified, and the piston rod of the second thrust cylinder 11 can be controlled to independently extend or retract; the first reversing valve 151, the second stop valve 13, the first stop valve 12 and the third stop valve 10 are all powered on, and hydraulic oil can be controlled to flow through the hydraulic elements of the horizontal pushing systems of the first reversing valve 151, the second stop valve 13, the first stop valve 12, the third stop valve 10, the first horizontal pushing cylinder 19 and the second horizontal pushing cylinder 11 through pipelines; after the repeated movement of the horizontal pushing oil cylinder and the hydraulic oil flows through each hydraulic element, air in the horizontal pushing oil cylinder and the pipeline can be removed.

The above description is only for the preferred embodiment of the present application and should not be taken as limiting the present application in any way, and although the present application has been disclosed in the preferred embodiment, it is not intended to limit the present application, and those skilled in the art should understand that they can make various changes and modifications within the technical scope of the present application without departing from the scope of the present application, and therefore all the changes and modifications can be made within the technical scope of the present application.