Large aperture rib-stiffened tensioned deployable antenna mechanism

Abstract

The application discloses a large-diameter rib-column tension type deployable antenna mechanism and relates to a deployable antenna, which is used for solving the problems of the current lack of large-scale deployment mechanism of the existing tension type antenna mechanism and the large mass and low rigidity of the large-diameter antenna deployment structure. The application comprises a telescopic column, a plurality of rib units and a motor screw rod control unit. The motor screw rod control unit is installed in the middle of the telescopic column. The plurality of rib units are arranged in the circumferential direction. The root of each rib unit is connected with the motor screw rod control unit. The application adopts the bifurcation design of the rib end, reduces the length of the outermost circle of the tension cable, reduces the rope suspension depth, can obtain the effective diameter of the large antenna with less rib number, and makes the structure mass lighter due to the less rib number. The three-circle cross tension cable between the adjacent ribs, the telescopic column in the center and the tension cable at the rib end are designed, so that the structure is tensioned into a whole, and the rigidity of the structure is improved. The application belongs to the technical field of aerospace engineering.

Description

TECHNICAL FIELD

[0001] The present application relates to a tension antenna, in particular to a large aperture rib column tension type deployable antenna mechanism, and belongs to the technical field of aerospace engineering. BACKGROUND

[0002] With the development of aerospace industry, higher requirements are put forward for the information communication distance and quality of the satellite-borne antenna and the resolution of the earth observation. Large aperture, lightweight, high storage ratio and other factors have become the development trend of space-borne antennas at home and abroad. Space folding mechanism has become the focus of application in aerospace engineering and has high application value. However, with the more urgent application demand of large aperture antenna, the mass and stiffness of the deployable mechanism become the factors restricting the development of large antenna mechanism.

[0003] In summary, the development of the antenna deployment mechanism has the following shortcomings:

[0004] There is a lack of large-size deployable mechanism, and lightweight design and structural stiffness optimization design are needed for large-aperture antenna deployment mechanism. SUMMARY

[0005] The present application is to solve the problem that the existing tension antenna mechanism currently lacks large-scale deployment mechanism, and the large-aperture antenna deployment structure has large mass and low stiffness, and further proposes a large-aperture rib column tension type deployable antenna mechanism.

[0006] The technical scheme adopted to solve the above problems is:

[0007] The present application comprises a telescopic stand, a plurality of rib units and a motor screw control unit, the motor screw control unit is installed in the middle of the telescopic stand, the plurality of rib units are arranged uniformly in the circumferential direction, and the root of each rib unit is connected with the motor screw control unit.

[0008] Further, each rib unit comprises four unit modules, namely a first unit module, a second unit module, a third unit module and a fourth unit module, one end of the second unit module is hinged with the first unit module through a first connecting piece, the other end of the second unit module is hinged with the third unit module and the fourth unit module through a second connecting piece, the third unit module and the fourth unit module are arranged in a V shape, and the opening faces outward.

[0009] Further, the first connecting piece comprises a first hinge joint, a first vertical rod, a second hinge joint, a first connecting rod and a first sliding block, the upper and lower ends of the first vertical rod are respectively provided with the first hinge joint and the second hinge joint, the first sliding block is sleeved on the first vertical rod, the two sides of the first sliding block are rotatably connected with two first connecting rods, and one end of each first connecting rod is rotatably connected with the first sliding block;

[0010] The second connecting piece comprises a third hinge joint, a second vertical rod, a fourth hinge joint, a second connecting rod and a second sliding block. The upper end of the second vertical rod is connected with the third hinge joint. The lower end of the second vertical rod is connected with the fourth hinge joint. The second sliding block is sleeved on the second vertical rod. The second sliding block is rotatably connected with three connecting rods.

[0011] Further, each unit module comprises two basic deployable units. The two basic deployable units are hingedly connected through a third connecting piece. The third connecting piece comprises a central rod, a sliding block, a spring, a fifth hinge joint and a sixth hinge joint. The sliding block and the spring are sequentially sleeved on the central rod from top to bottom. The upper end of the central rod is provided with the fifth hinge joint. The lower end of the central rod is provided with the sixth hinge joint.

[0012] Further, each basic deployable unit comprises a small support rod, an upper chord rod, a lower chord rod, a small inclined web rod and a large inclined web rod. One end of the upper chord rod is connected with the upper end of the third connecting piece central rod through the fifth hinge joint. One end of the lower chord rod is connected with the lower end of the third connecting piece central rod through the sixth hinge joint. One end of the small inclined web rod is connected with the fifth hinge joint. The other end of the small inclined web rod is connected with one end of the large inclined web rod. One end of the small support rod is connected with the sliding block in the third connecting piece. The other end of the small support rod is connected with the small inclined web rod.

[0013] Further, the motor screw control unit comprises a top plate, a bottom plate, a motor, a motor support, a third sliding block, a screw rod, a bearing and a connecting rod. The motor is fixedly connected with the bottom plate through the motor support. One end of the screw rod is connected with the motor output shaft. The other end of the screw rod is connected with the top plate through the bearing. The third sliding block is sleeved on the screw rod and is threadedly connected with the screw rod. The outer end of the third sliding block is provided with a plurality of connecting rods in the circumferential direction. The end of each connecting rod is rotatably connected with a connecting rod.

[0014] Further, the large-diameter rib-column tension type deployable antenna mechanism further comprises an inter-rib tension cable and a column tension cable. The inter-rib tension cable is connected with the rib unit. One end of the column tension cable is connected with the end of the rib unit. The other end of the column tension cable is connected with the upper and lower ends of the telescopic column.

[0015] Further, the telescopic column is two, which are respectively located on the upper and lower surfaces of the motor screw control unit. Each telescopic column comprises a fixed cylinder, a first moving cylinder and a second moving cylinder. The fixed cylinder, the first moving cylinder and the second moving cylinder are sequentially and slidably connected from outside to inside.

[0016] Further, the bottom end of each fixed cylinder is provided with a rope driving and folding device. The device comprises two rope wheels. Each rope wheel is provided with three rope winding grooves.

[0017] Further, the upper end of the fixed cylinder, the upper and lower ends of the first moving cylinder and the lower end of the second moving cylinder are all provided with a fixed pulley for winding the rope.

[0018] The beneficial effects of the present application are:

[0019] 1、 The present application is composed of a plurality of basic deployable units with the same parameters, and the number of rib units can be adjusted to adapt to different caliber sizes;

[0020] 2、 The present application has the same parameters of the basic deployable unit, and the adjacent units have connecting rods for synchronization, and the rest share a driving spring for synchronization. Each rib unit is controlled by a center screw-rod-connecting rod for synchronization, which is lighter in mass and has no complex rope structure compared with the commonly used motor rope speed control, avoiding the risk of entanglement;

[0021] 3、 The present application adopts the bifurcation design of the rib end, which reduces the length of the outermost circle of the tension cable, so that the rope suspension depth is reduced, and a larger effective caliber of the antenna can be obtained with fewer ribs, and fewer ribs also make the structure lighter in mass;

[0022] 4、 The three-circle cross rib tension cable between adjacent ribs and the telescopic column at the center and the column tension cable at the rib end are designed to make the structure tensioned as a whole, which can improve the stiffness of the structure. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic diagram of the deployed state structure of the present application;

[0024] Figure 2 is a schematic diagram of the structure of the present application in the folded state;

[0025] Figure 3 is a schematic diagram of the structure of the rib unit;

[0026] Figure 4 is a schematic diagram of the node position of a single rib;

[0027] Figure 5 is a schematic diagram of the structure of the first connecting piece;

[0028] Figure 6 is a schematic diagram of the structure of the second connecting piece;

[0029] Figure 7 is a schematic diagram of the structure of the third connecting piece.

[0030] Figure 8 is a schematic diagram of the structure of the basic deployable unit;

[0031] Figure 9 is a schematic diagram of the right-angle joint of the large diagonal web member;

[0032] Figure 10 is a schematic diagram of the structure of the rotating joint in the third connecting piece;

[0033] Figure 11is a structural schematic diagram of a motor screw control unit;

[0034] Figure 12 is a structural schematic diagram of a tension cable unit;

[0035] Figure 13 is a schematic diagram of the principle of the rope drive sleeve;

[0036] Figure 14 is a structural schematic diagram of a telescopic column;

[0037] Figure 15 is a structural schematic diagram of a rope pulley;

[0038] Figure 16 is a structural schematic diagram of a fixed pulley;

[0039] Figure 17 is a structural schematic diagram of a locking device between the sleeves in the telescopic column.

[0040] In the figure: 1-telescopic column; 1-1-fixed cylinder, 1-2-first moving cylinder; 1-3 second moving cylinder; 2-rib unit; 3-inter-rib tension cable; 4-motor screw control unit; 5-first connecting piece; 5-1-first hinge joint; 5-2-first vertical rod; 5-3-second hinge joint; 5-4-first connecting rod; 5-5-first sliding block; 6-second connecting piece; 6-1-third hinge joint; 6-2-second vertical rod; 6-3-fourth hinge joint; 6-4 second connecting rod; 6-5-second sliding block; 7-third connecting piece hinge; 7-1-center rod; 7-2-sliding block; 7-3-spring; 7-4-fifth hinge joint; 7-5-sixth hinge joint; 8-basic deployable unit; 8-1-small support rod; 8-2-upper chord rod; 8-3-lower chord rod; 8-4-small diagonal web rod; 8-5-large diagonal web rod; 9-top plate; 10-bottom plate; 11-motor; 12-motor support; 13-third sliding block; 14-screw rod; 15-bearing; 16-connecting rod; 17-rope pulley; 18-pivot; 19-brass sleeve; 20-split pin; 21-A hinge; 22-spring; 23-locking pin; 24-B hinge; 25-locking hole; 26-unlocking screw; 27-locking hole; 28-threaded fixing hole; 29-inner guide rail; 30-column tension cable. DETAILED DESCRIPTION

[0041] The large-diameter rib column tension type deployable antenna mechanism described in the embodiment increases the rib nodes on the outermost circle through the split structure design at the end of the rib unit, reduces the overhang depth, and improves the effective aperture of the rib antenna.

[0042] As Figure 1 and Figure 2As shown, the present embodiment includes a telescopic column 1, a plurality of rib units 2, an intercostal tension cable 3, a column tension cable 30 and a motor screw control unit 4,

[0043] As shown in Figure 3 , Figure 4 , each rib unit 2 is in a "Y" shape structure, each rib unit 2 includes four unit modules, which are first unit module A, second unit module B, third unit module C and fourth unit module D, respectively, one end of the second unit module B is hinged to the first unit module A through a first connecting piece 5, the other end of the second unit module B is hinged to the third unit module C and the fourth unit module D through a second connecting piece 6, the third unit module C and the fourth unit module D are designed in a "V" shape bifurcation, and the opening is directed outward. The included angle between the third unit module C and the fourth unit module D is 45°.

[0044] As shown in Figure 5 , the first connecting piece 5 includes a first hinge joint 5-1, a first vertical rod 5-2, a second hinge joint 5-3, a first connecting rod 5-4 and a first sliding block 5-5, the upper and lower ends of the first vertical rod 5-2 are respectively provided with the first hinge joint 5-1 and the second hinge joint 5-3, the first sliding block 5-5 is sleeved on the first vertical rod 5-2, and the two first connecting rods 5-4 are rotatably connected to the two sides of the first sliding block 5-5, one end of each first connecting rod 5-4 is rotatably connected to the first sliding block 5-5, and the other end is rotatably connected to the upper chord of the adjacent left and right units; the effect of the connecting rod makes the two upper chords keep the same opening angle.

[0045] As shown in Figure 6 , the second connecting piece 6 includes a third hinge joint 6-1, a second vertical rod 6-2, a fourth hinge joint 6-3, a second connecting rod 6-4, and a second sliding block 6-5; the upper end of the second vertical rod 6-2 is connected with the third hinge joint 6-1; the lower end of the second vertical rod 6-2 is connected with the fourth hinge joint 6-3, the second sliding block 6-5 is sleeved on the second vertical rod 6-2, and three second connecting rods 6-4 are rotatably connected to the second sliding block, the three connecting rods 6-4 are rotatably connected to the upper chords of the adjacent left and right units, and the upper and lower hinge joints of the second vertical rod 6-2 are also designed in a bifurcated form, the included angle of the bifurcation is 45 degrees, and three connecting rods and a bifurcated sliding block are designed.

[0046] As shown in Figure 7As shown, each unit module includes two basic deployable units 8, which are hinged by a third connecting piece 7. The third connecting piece 7 includes a center rod 7-1, a slider 7-2, a spring 7-3, a fifth hinge joint 7-4 and a sixth hinge joint 7-5; the slider 7-2 and the spring 7-3 are sequentially sleeved on the center rod 7-1 from top to bottom, the upper end of the center rod 7-1 is provided with the fifth hinge joint 7-4, and the lower end of the center rod 7-1 is provided with the sixth hinge joint 7-5.

[0047] That is, there are eight basic deployable units on each rib, wherein each bifurcated structure (i.e., the third unit module C and the fourth unit module D) has two basic deployable units, so that the bifurcated structure has four basic deployable units, the more the number of units on the bifurcation, that is, the closer the bifurcation position to the center connecting plate, the more the number of deployable units on each rib, and the greater the mass; when the number of units on the bifurcation is small, the bifurcation is too short, and it cannot be ensured that the end nodes of the bifurcation are uniformly distributed on the outermost envelope circle. The size of the bifurcation angle is related to the length of the bifurcation and the distribution position of the end nodes of the bifurcation, and the bifurcation position and the number of units on the bifurcation should be determined by ensuring that the number of units on the rib is small (light mass) and the end nodes are uniformly distributed.

[0048] As shown in Figure 8 each basic deployable unit 8 includes a small support rod 8-1, an upper chord rod 8-2, a lower chord rod 8-3, a small diagonal web rod 8-4 and a large diagonal web rod 8-5, one end of the upper chord rod is connected with the upper end of the center rod of the third connecting piece through the fifth hinge joint, one end of the lower chord rod is connected with the lower end of the center rod of the third connecting piece through the sixth hinge joint, one end of the small diagonal web rod is connected with the fifth hinge joint, and the other end is connected with one end of the large diagonal web rod 8-5, one end of the small support rod is connected with the slider in the third connecting piece, and the other end is connected with the small diagonal web rod.

[0049] The joint of the large diagonal web rod 8-5 is designed as a right-angle joint connected with the joint of the lower chord rod connected with the vertical rod, which is designed to ensure that the large diagonal web rod 8-5 is parallel to the lower chord rod when the unit is folded, so as to avoid occupying too much internal space formed by the upper rod and the lower rod when folded due to the certain angle between the large diagonal web rod 8-5 and the lower chord rod, as shown in Figure 9 the diagonal rod is parallel to the lower rod, and the occupied internal space is the smallest, which avoids structural interference and reduces the volume envelope when folded.

[0050] As shown in Figure 10As shown, the shaft design at the rotating joint in the third connecting member 7 is shown in the figure. There is a pin 18, two copper sleeves 19 and an end-fixed cotter pin 20 at the joint. The copper sleeve 19 is located between the pin 18 and the A hinge 21, which reduces the friction at the rotating joint and improves the rotation accuracy. The locking principle is to use the spring 22 to push the locking pin 23 into the locking hole 25 on the B hinge 24 to form a joint lock. When the mechanism is deployed in place, the locking holes 25 on the A hinge 21 and the B hinge 24 are concentric, so the locking pin 23 is inserted into the hole under the elastic force of the spring 22. During the ground experiment, it is necessary to repeatedly lock, unlock, expand and contract. Just push the unlocking screw 26 along the slot to drive the locking pin 23 to move inward to achieve unlocking.

[0051] like Figure 11 As shown, the motor screw control unit 4 includes a top plate 9, a bottom plate 10, a motor 11, a motor bracket 12, a third slider 13, a screw 14, a bearing 15 and a connecting rod 16. The motor 11 is fixedly connected to the bottom plate 10 through the motor bracket 12. One end of the screw 14 is connected to the motor output shaft, and the other end is connected to the top plate 9 through the bearing 15. The third slider 13 is sleeved on the screw 14 and is threadedly connected to the screw 14. The outer end of the third slider 13 is provided with a plurality of connecting rods along the circumferential direction, and the end of each connecting rod is rotatably connected to a connecting rod 16.

[0052] The edges of the top plate 9 and bottom plate 10 are provided with multiple connection holes along the circumference for connecting to the base of the rib unit. The outer edge connection holes of the top plate 9 are connected to the hinge joints of the upper chord rod 8-2 at the base of the rib unit, and the outer edge connection holes of the bottom plate 10 are connected to the hinge joints of the lower chord rod 8-3 at the base of the rib unit. When the motor 11 drives the screw rod 14 to rotate, the third slider 13 can reciprocate up and down in the vertical direction. The outer end of the third slider 13 is provided with multiple connecting rods along the circumference. One end of the connecting rod 16 is rotatably connected to the connecting rod of the third slider 13, and the other end is rotatably connected to the upper chord rod 8-2. The deployment angle of the upper chord rod is controlled by the motor.

[0053] The large-diameter rib column tensioned deployable antenna mechanism further includes an inter-rib tensioning cable 3 and a column tensioning cable 30. The inter-rib tensioning cable 3 is arranged at a position as shown in FIG. Figure 12 As shown, a total of three loops of cables are designed. The interrib tensioning cables 3 are laid on the two connected rib units 2 and between the bifurcations on the rib units. The interrib tensioning cables 3 are cross-arranged and connected to the upper and lower hinged joints of the vertical rod respectively; the column tensioning cable 30 is spindle-shaped, one end of the column tensioning cable 30 is connected to the end of the rib unit 2, and the other end of the column tensioning cable 30 is connected to the upper and lower ends of the retractable column 1.

[0054] In order to improve the overall stiffness of the deployment mechanism, referring to the design of the ring-rib type deployment antenna structure, the upper and lower extendable telescopic columns 1 are designed, and the column tension cable 30 is connected from the end of the column to the end of the rib unit 2. Analysis of the structure shows that the arc-shaped rib will deform under the tension of the three-loop rib inter-tension cable 3, and the arc-shaped rib structure has a tendency to shrink inward. Adding the upper and lower column tension cable 30 can effectively reduce the deformation.

[0055] The telescopic column 1 is two, and the two telescopic columns are independently operated and located on the upper and lower surfaces of the motor screw control unit 4. Each telescopic column 1 includes a fixed cylinder 1-1, a first moving cylinder 1-2 and a second moving cylinder 1-3, which are sequentially connected by sliding from the outside to the inside.

[0056] As shown in Figures 13-14 , the two moving cylinders are retracted in the fixed cylinder 1-1, and the entire mechanism is in a retracted state. The inner surface of the fixed

[0057] cylinder 1-1, the inner and outer surfaces of the first moving cylinder 1-2, and the inner surface of the second moving cylinder 1-3 are each uniformly distributed with three straight line guides 1-4. The lower end of the first moving cylinder 1-2 is provided with three pulleys that cooperate with the straight line guides on the inner surface of the fixed cylinder for sliding; the upper end of the first moving cylinder 1-2 is provided with three pulleys that cooperate with the three straight line guides of the second moving cylinder for sliding; the lower end of the second moving cylinder 1-3 is provided with three pulleys that cooperate with the three straight line guides of the first moving cylinder for sliding. The straight line motion precision of the moving cylinder during deployment is ensured. The fixed cylinder 1-1 is the largest diameter sleeve type extension mechanism cylinder, which provides storage and movement space for the inner cylinder. The first moving cylinder 1-2 is located inside the fixed cylinder 1-1, and the outer diameter of the first moving cylinder 1-2 is reduced by 20mm relative to the outer diameter of the fixed cylinder 1-1. The second moving cylinder 1-3 is also relative to the first moving cylinder 1-2. Adjacent two cylinders are connected by sliding cooperation of pulleys and guides. The lower pulley on the lower joint of the first moving cylinder 1-2 slides with the inner guide of the fixed cylinder 1-1. Locking mechanisms are provided between each sleeve, and the locking pin moves along the inner guide 29 during the deployment of the column, until it is inserted into the locking hole 27 to achieve locking in place under the action of the spring thrust after moving to the position of the locking hole 27. As shown in Figure 17 .

[0058] A fixed pulley for winding a rope is provided at the upper end of the fixed cylinder 1-1, the upper and lower ends of the first moving cylinder 1-2, and the lower end of the second moving cylinder 1-3. The fixed pulley is Figure 15The winch mechanism works, the first movement cylinder 1-2 is lifted by the fixed pulley to realize the unfolding, and the second movement cylinder 1-3 and the fixed cylinder 1-1 are connected by the fixed length rope, so that the second movement cylinder 1-3 is necessarily moved outward with the extension of the first movement cylinder 1-2, thereby realizing the synchronous unfolding of the mechanism. Then, the locking mechanism works to realize the locking of the mechanism. When the mechanism needs to be folded, the motor is reversely rotated to drive the reverse arrangement of the rope wheel driving system, so that the synchronous folding of the mechanism can be realized. The rope driving sleeve type scheme principle diagram is as shown in Figure 13

[0059] As shown in Figure 15 Each fixed cylinder is provided with a rope driving and folding device at the bottom end; the device comprises a motor, a gear set and two rope wheels 17, each rope wheel 17 is provided with three rope winding grooves, one of the rope wheels 17 is wound with three unfolding ropes, and the other rope wheel 17 is wound with three folding ropes. The two rope wheels 17 are driven by the motor through the gear transmission, and the parameters of the two gears are the same, because the movement length ratio of the recovery and release ropes is 1:1. The output shaft of the motor is connected with one rope wheel through the driving gear, the driven gear is engaged with the driving gear and connected with the other rope wheel, and the rotating directions of the two rope wheels are opposite, so that when the winding directions of the unfolding ropes and the folding ropes are the same, when the motor drives the rope pulley to rotate, one realizes the folding winding of the unfolding rope, and the other realizes the release of the folding rope.

[0060] Working process:

[0061] The antenna mechanism unfolding steps are as follows: after the mechanism is unlocked, the rib upper basic unfolding units are gradually unfolded under the elastic pushing of the driving spring 7-3, and the unfolding is carried out at the same time, and the unfolding angle of each unit module is the same under the action of the sliding block 5-5 and the connecting rod 5-4, the control unit of the motor lead screw in the center position controls the unfolding speed, the motor 11 drives the lead screw 14 to rotate, and the sliding block 13 sleeved on the lead screw 14 moves upward, and the unfolding angle of the upper rod in the control unit is controlled through the connecting rod 16, when all the rib units are unfolded to the locking position, the telescopic column 1 starts to unfold, the motor in the rope driving and folding device starts to work, drives the unfolding rope to wind on the rope wheel, and the folding rope is released, and each sleeve is unfolded to the locking position.

[0062] The above is only a preferred embodiment of the present application, and does not limit the present application in any form, although the present application has been disclosed as above, however, it is not intended to limit the present application, any person skilled in the art, without departing from the technical solution of the present application, can make some changes or modifications to the above disclosed technical content to make equivalent embodiments, but as long as it does not deviate from the technical solution of the present application, according to the technical essence of the present application, within the spirit and principle of the present application, any simple modification, equivalent replacement and improvement of the above embodiments are still within the protection scope of the technical solution of the present application.​

Claims

1. A large-diameter rib-tensioned deployable antenna mechanism, characterized by: The large-caliber rib column tensioned deployable antenna mechanism comprises a telescopic column (1), a plurality of rib units (2) and a motor screw control unit (4), wherein the motor screw control unit (4) is mounted in the middle of the telescopic column (1), the plurality of rib units (2) are evenly distributed along the circumferential direction, and the root of each rib unit (2) is connected to the motor screw control unit (4); Each rib unit (2) includes four unit modules, namely a first unit module (A), a second unit module (B), a third unit module (C) and a fourth unit module (D); one end of the second unit module (B) is hinged to the first unit module (A) via a first connecting member (5); the other end of the second unit module (B) is hinged to the third unit module (C) and the fourth unit module (D) via a second connecting member (6); the third unit module (C) and the fourth unit module (D) are arranged in a V shape with their openings facing outwards; The large-caliber rib-column tensioned deployable antenna mechanism further comprises an inter-rib tensioning cable (3) and a column tensioning cable (30), wherein the inter-rib tensioning cable (3) is connected to the rib unit (2), one end of the column tensioning cable (30) is connected to the end of the rib unit (2), and the other end of the column tensioning cable (30) is connected to the upper and lower ends of the telescopic column (1).

2. The large-diameter rib-tensioned deployable antenna mechanism according to claim 1, characterized in that: The first connecting member (5) comprises a first hinge joint (5-1), a first vertical rod (5-2), a second hinge joint (5-3), a first connecting rod (5-4) and a first slider (5-5); the first hinge joint (5-1) and the second hinge joint (5-3) are respectively provided at the upper and lower ends of the first vertical rod (5-2); the first slider (5-5) is sleeved on the first vertical rod (5-2); the two sides of the first slider (5-5) are rotatably connected to the two first connecting rods (5-4); and one end of each first connecting rod (5-4) is rotatably connected to the first slider (5-5); The second connecting member (6) comprises a third hinge joint (6-1), a second vertical rod (6-2), a fourth hinge joint (6-3), a second connecting rod (6-4), and a second slider (6-5); the upper end of the second vertical rod (6-2) is connected to the third hinge joint (6-1); the lower end of the second vertical rod (6-2) is connected to the fourth hinge joint (6-3); the second slider (6-5) is sleeved on the second vertical rod (6-2); and the second slider (6-5) is rotatably connected to three second connecting rods (6-4).

3. The large-diameter rib-tensioned deployable antenna mechanism according to claim 1, characterized in that: Each unit module comprises two basic expandable units (8), the two basic expandable units (8) are hinged via a third connecting member (7), the third connecting member (7) comprising a central rod (7-1), a slider (7-2), a spring (7-3), a fifth hinge joint (7-4) and a sixth hinge joint (7-5); the central rod (7-1) is sequentially provided with a slider (7-2) and a spring (7-3) from top to bottom, the upper end of the central rod (7-1) is provided with a fifth hinge joint (7-4), and the lower end of the central rod (7-1) is provided with a sixth hinge joint (7-5).

4. The large-diameter rib-tensioned deployable antenna mechanism according to claim 3, characterized in that: Each basic expandable unit (8) comprises a small support rod (8-1), an upper chord rod (8-2), a lower chord rod (8-3), a small diagonal web rod (8-4) and a large diagonal web rod (8-5), one end of the upper chord rod (8-2) is connected to the upper end of the central rod (7-1) of the third connecting member (7) through a fifth hinge joint (7-4), one end of the lower chord rod (8-3) is connected to the lower end of the central rod (7-1) of the third connecting member (7) through a sixth hinge joint (7-5), one end of the small diagonal web rod (8-4) is connected to the fifth hinge joint (7-4), and the other end is connected to one end of the large diagonal web rod (8-5), one end of the small support rod (8-1) is connected to the slider (7-2) in the third connecting member (7), and the other end is connected to the small diagonal web rod (8-4).

5. The large-diameter rib-tensioned deployable antenna mechanism according to claim 1, characterized in that: The motor screw control unit (4) comprises a top plate (9), a bottom plate (10), a motor (11), a motor bracket (12), a third slider (13), a screw (14), a bearing (15) and a connecting rod (16), wherein the motor (11) is fixedly connected to the bottom plate (10) via the motor bracket (12), one end of the screw (14) is connected to the output shaft of the motor (11), and the other end is connected to the top plate (9) via the bearing (15), the third slider (13) is sleeved on the screw (14) and is threadedly connected to the screw (14), and a plurality of connecting rods are provided at the outer end of the third slider (13) along the circumferential direction, and the end of each connecting rod is rotatably connected to a connecting rod (16).

6. The large-diameter rib-tensioned deployable antenna mechanism according to claim 1, characterized in that: There are two retractable columns (1), which are respectively located on the upper and lower surfaces of the motor screw control unit (4). Each retractable column (1) comprises a fixed cylinder (1-1), a first moving cylinder (1-2) and a second moving cylinder (1-3). The fixed cylinder (1-1), the first moving cylinder (1-2) and the second moving cylinder (1-3) are slidably connected in sequence from the outside to the inside.

7. The large-diameter rib-tensioned deployable antenna mechanism according to claim 6, characterized in that: The bottom end of each fixed cylinder (1-1) is provided with a rope driving and retracting device; the device comprises two rope wheels (17), and each rope wheel (17) is provided with three rope winding grooves.

8. The large-diameter rib-tensioned deployable antenna mechanism according to claim 7, characterized in that: The upper end of the fixed cylinder (1-1), the upper and lower ends of the first moving cylinder (1-2), and the lower end of the second moving cylinder (1-3) are all provided with fixed pulleys for winding ropes.

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