CN108252991B

CN108252991B - Foldable spherical structure

Info

Publication number: CN108252991B
Application number: CN201711459022.4A
Authority: CN
Inventors: 陈焱; 朱晒红; 吕玮琳; 王国慧; 张临风; 易波; 马家耀
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2017-12-28
Filing date: 2017-12-28
Publication date: 2021-09-07
Anticipated expiration: 2037-12-28
Also published as: CN108252991A

Abstract

The invention discloses a foldable spherical structure, which comprises six folding units and a first reference plane, wherein the six folding units are connected with connecting points on the six folding units through revolute pairs to form a hemispherical or spherical structure, the six folding units can be used for folding the foldable spherical structure from a space state to a plane state through relative movement between the six folding units, and the folding change of the six folding units is determined by the shape and the size of each folding unit and the axial direction of the revolute pairs. The invention can realize two stable states of folding and unfolding, has smaller volume when folded and is convenient for launching or transportation, and has larger working space when unfolded; the whole structure has only one degree of freedom, and the motion control is simple; the method has the advantages of simple production and processing, convenient motion control, high reliability and the like, and has important significance and wide application prospect in a plurality of fields such as aerospace and the like.

Description

Foldable spherical structure

Technical Field

The invention relates to a foldable spherical structure with single degree of freedom and a large folding-unfolding ratio, in particular to a structure which realizes the conversion between a plane and a spherical surface by single driving.

Background

The deployable structure is a unique engineering structure. The structure has two states of unfolding and folding, and the foldable structure is usually in the folding state for convenient storage and transportation; when the foldable structure is needed to be utilized, the foldable structure is unfolded to a working state, and a larger space can be covered. The expandable structure is widely applied to aerospace, building structures, artworks and daily life due to the advantages of easy production, convenient storage and transportation, high folding-unfolding ratio, convenient disassembly and the like.

The existing spherical expandable structure can be applied to the fields of aerospace, building and the like, and some structures are designed into toys, such as Hoberman Sphere designed by Chuck Hoberman, and the expanded state of the spherical expandable structure is a truncated icosahedron consisting of 6 rings. The existing spherical surface expandable structure has the defects of larger volume, more complex structure and the like after being folded.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a foldable spherical structure which can realize two states of folding and unfolding and has simple installation and operation processes, wherein the structure is an extensible structure which comprises a rigid over-constraint mechanism and has two states, the volume is small during folding and is convenient for launching or transporting, and a larger working space is provided during unfolding; the whole structure has only one degree of freedom, and the motion control is simple; the method has the advantages of simple production and processing, convenient motion control, high reliability and the like, and has important significance and wide application prospect in a plurality of fields such as aerospace and the like.

The technical scheme adopted by the invention is as follows: a foldable spherical structure comprising six folding units capable of folding the foldable spherical structure from a spatial state to a planar state by relative movement between each other, and a first reference plane; the sizes of the six folding units are sequentially increased in an increasing mode and respectively form a first folding unit, a second folding unit, a third folding unit, a fourth folding unit, a fifth folding unit and a sixth folding unit;

the first folding unit, the second folding unit, the fifth folding unit and the sixth folding unit are all provided with three connecting points at the same positions, namely a first connecting point, a second connecting point and a third connecting point; in any folding unit of the first folding unit, the second folding unit, the fifth folding unit and the sixth folding unit, the first connecting point, the second connecting point and the third connecting point are positioned on the same circle or two or three concentric circles, the first connecting point and the third connecting point are positioned on the same straight line passing through the circle center of the circle or the concentric circle, and the included angle between the first connecting point and the connecting line of the second connecting point and the circle center of the circle or the concentric circle is called as a first included angle;

the third folding unit and the fourth folding unit are respectively provided with four connecting points at the same positions, namely a first connecting point, a second connecting point, a third connecting point and a fourth connecting point; in any folding unit of the third folding unit and the fourth folding unit, the first connecting point, the second connecting point, the third connecting point and the fourth connecting point are positioned on the same circle or two or three or four concentric circles, the first connecting point and the fourth connecting point are positioned on the same straight line passing through the circle center of the circle or the concentric circle, and the included angles between the second connecting point and the circle center connecting line of the circle or the concentric circle are the same as the included angles between the third connecting point and the circle center connecting line of the circle or the concentric circle and the included angles between the fourth connecting point and the circle center connecting line of the circle or the concentric circle and the included angles are the same as the first included angles;

the first connecting point of the first folding unit is connected with the third connecting point of the second folding unit through a first revolute pair, the third connecting point of the first folding unit is connected with the first connecting point of the second folding unit through a second revolute pair, the first connecting point of the third folding unit is connected with the fourth connecting point of the fourth folding unit through a third revolute pair, the fourth connecting point of the third folding unit is connected with the first connecting point of the fourth folding unit through a fourth revolute pair, the first connecting point of the fifth folding unit is connected with the third connecting point of the sixth folding unit through a fifth revolute pair, and the third connecting point of the fifth folding unit is connected with the first connecting point of the sixth folding unit through a sixth revolute pair; the axes of the first rotating pair, the second rotating pair, the third rotating pair, the fourth rotating pair, the fifth rotating pair and the sixth rotating pair are all in the first reference plane and intersect at the same point, which is called a first intersection point;

the second connecting point of the first folding unit is connected with the third connecting point of the third folding unit through a seventh revolute pair, the second connecting point of the second folding unit is connected with the third connecting point of the fourth folding unit through an eighth revolute pair, the second connecting point of the third folding unit is connected with the second connecting point of the fifth folding unit through a ninth revolute pair, and the second connecting point of the fourth folding unit is connected with the second connecting point of the sixth folding unit through a tenth revolute pair; and the axes of the seventh revolute pair, the eighth revolute pair, the ninth revolute pair and the tenth revolute pair are intersected at the first intersection point.

Wherein the first included angle is any angle greater than zero degrees and less than ninety degrees.

Wherein, the revolute pair is a hinge or a bearing.

Wherein the folding unit has a ring-shaped or semi-ring-shaped or curved or broken line profile.

The other technical scheme of the invention is as follows: a foldable spherical structure comprising six folding units capable of folding the foldable spherical structure from a spatial state to a planar state by relative movement between each other, and a second reference plane; the sizes of the six folding units are sequentially increased in an increasing mode and respectively form a first folding unit, a second folding unit, a third folding unit, a fourth folding unit, a fifth folding unit and a sixth folding unit;

the first folding unit, the second folding unit, the fifth folding unit and the sixth folding unit are all provided with four connecting points at the same positions, namely a first connecting point, a second connecting point, a third connecting point and a fourth connecting point; in any folding unit of the first folding unit, the second folding unit, the fifth folding unit and the sixth folding unit, the first connection point, the second connection point, the third connection point and the fourth connection point are located on the same circle or two or three or four concentric circles, the first connection point and the third connection point are on the same straight line passing through the circle center or the concentric circle center, the second connection point and the fourth connection point are on the same straight line passing through the circle center or the concentric circle center, and the included angle between the first connection point and the circle center or the concentric circle center is called as a second included angle;

the third folding unit and the fourth folding unit are respectively provided with six connecting points at the same positions, namely a first connecting point, a second connecting point, a third connecting point, a fourth connecting point, a fifth connecting point and a sixth connecting point; in any of the third folding unit and the fourth folding unit, the first connection point, the second connection point, the third connection point, the fourth connection point, the fifth connection point and the sixth connection point are located on the same circle or on two or three or four or five or six concentric circles, the first connecting point and the fourth connecting point are on the same straight line passing through the center of the circle or the concentric circle, the second connecting point and the fifth connecting point are on the same straight line passing through the center of the circle or the concentric circle, the third connecting point and the sixth connecting point are on the same straight line passing through the center of the circle or the concentric circles, the included angles of the second connecting point, the first connecting point and the connecting line of the circle center of the circle or the concentric circle are the same as the included angles of the third connecting point and the fourth connecting point and the connecting line of the circle center of the circle or the concentric circle, and the included angles are the same as the second included angle;

the first connecting point of the first folding unit is connected with the third connecting point of the second folding unit through a first revolute pair, the third connecting point of the first folding unit is connected with the first connecting point of the second folding unit through a second revolute pair, the first connecting point of the third folding unit is connected with the fourth connecting point of the fourth folding unit through a third revolute pair, the fourth connecting point of the third folding unit is connected with the first connecting point of the fourth folding unit through a fourth revolute pair, the first connecting point of the fifth folding unit is connected with the third connecting point of the sixth folding unit through a fifth revolute pair, and the third connecting point of the fifth folding unit is connected with the first connecting point of the sixth folding unit through a sixth revolute pair; the axes of the first rotating pair, the second rotating pair, the third rotating pair, the fourth rotating pair, the fifth rotating pair and the sixth rotating pair are all in the second reference plane and are intersected at the same point, and the second intersection point is called as a second intersection point;

the second connection point of the first folding unit is connected with the third connection point of the third folding unit through a seventh revolute pair, the fourth connection point of the first folding unit is connected with the sixth connection point of the third folding unit through an eighth revolute pair, the second connection point of the second folding unit is connected with the third connection point of the fourth folding unit through a ninth revolute pair, the fourth connection point of the second folding unit is connected with the sixth connection point of the fourth folding unit through a tenth revolute pair, the second connection point of the third folding unit is connected with the second connection point of the fifth folding unit through an eleventh revolute pair, the fifth connection point of the third folding unit is connected with the fourth connection point of the fifth folding unit through a twelfth revolute pair, and the second connection point of the fourth folding unit is connected with the second connection point of the sixth folding unit through a thirteenth revolute pair, a fifth connecting point of the fourth folding unit is connected with a fourth connecting point of the sixth folding unit through a fourteenth revolute pair; and the axes of the seventh revolute pair, the eighth revolute pair, the ninth revolute pair, the tenth revolute pair, the eleventh revolute pair, the twelfth revolute pair, the thirteenth revolute pair and the fourteenth revolute pair are intersected at the second intersection point.

Wherein the second included angle is any angle greater than zero degrees and less than ninety degrees.

Wherein, the revolute pair is a hinge or a bearing.

The invention has the beneficial effects that:

the invention is a foldable structure with single degree of freedom, can realize the folding and unfolding of the sphere through a drive, it is convenient to mount and use;

the folding table has a large folding and unfolding ratio, and can obtain a stable state with a small volume after being folded, so that the folding table is convenient to transport and store;

the shape and the size of the folding unit can be designed according to actual requirements;

and fourthly, the structure of the folding device is designed functionally, different appearance contours can be designed according to actual needs, and the size of each folding unit can be designed according to the requirements of actual application occasions.

Drawings

FIG. 1 is a schematic structural diagram of a first embodiment of a foldable spherical structure provided by the present invention;

FIGS. 2-1 to 2-6 are schematic structural views of six folding units in FIG. 1;

FIGS. 3-1 to 3-7 are schematic views of two folding units respectively connected to each revolute pair in FIG. 1;

FIG. 4 is a schematic diagram illustrating a position relationship of a kinematic pair disposed in the foldable spherical structure shown in FIG. 1;

FIGS. 5-1 to 5-5 are schematic views illustrating the unfolding and folding processes of the foldable spherical structure shown in FIG. 1; wherein fig. 5-1 and 5-5 are schematic views of two fully folded states of the foldable spherical structure shown in fig. 1, respectively;

FIG. 6 is a schematic structural diagram of a second embodiment of a foldable spherical structure provided by the present invention;

FIGS. 7-1 to 7-6 are schematic structural views of six folding units of FIG. 6;

FIGS. 8-1 to 8-7 are schematic views of two folding units respectively connected to each revolute pair in FIG. 6;

FIG. 9 is a schematic diagram illustrating the position relationship of the kinematic pair disposed in the spherical foldable structure shown in FIG. 6;

FIGS. 10-1 to 10-5 are schematic views illustrating the unfolding and folding processes of the foldable spherical structure shown in FIG. 6; wherein fig. 10-1 and 10-5 are two schematic fully-folded views of the foldable spherical structure shown in fig. 6, respectively.

In the figure:

1I-the first reference plane in embodiment 1, α 1-the first included angle in embodiment 1, 1O-the first intersection point of the axes of the revolute pairs in embodiment 1, 1O 1-the center of the circle in the first folding unit in embodiment 1, 1O 2-the center of the circle in the second folding unit in embodiment 1, 1O 3-the center of the circle in the third folding unit in embodiment 1, 1O 4-the center of the circle in the fourth folding unit in embodiment 1, 1O 5-the center of the circle in the fifth folding unit in embodiment 1, 1O 6-the center of the circle in the sixth folding unit in embodiment 1;

1T 1-the first folding unit in example 1, 1T 2-the second folding unit in example 1; 1T 3-the third folded unit of example 1, 1T 4-the fourth folded unit of example 1, 1T 5-the fifth folded unit of example 1, 1T 6-the sixth folded unit of example 1;

1V 11-first folding unit first connection point in example 1, 1V 12-first folding unit second connection point in example 1, 1V 13-first folding unit third connection point in example 1, 1V 21-second folding unit first connection point in example 1, 1V 22-second folding unit second connection point in example 1, 1V 23-second folding unit third connection point in example 1, 1V 31-third folding unit first connection point in example 1, 1V 32-third folding unit second connection point in example 1, 1V 33-third folding unit third connection point in example 1, 1V 34-third folding unit fourth connection point in example 1, 1V 41-fourth folding unit first connection point in example 1, 1V 42-fourth folding unit second connection point in example 1, 1V 43-fourth folding unit third connection point in example 1, 1V 44-fourth folding unit fourth connection point in example 1, 1V 51-fifth folding unit first connection point in example 1, 1V 52-fifth folding unit second connection point in example 1, 1V 53-fifth folding unit third connection point in example 1, 1V 61-sixth folding unit first connection point in example 1, 1V 62-sixth folding unit second connection point in example 1, 1V 63-sixth folding unit third connection point in example 1;

1H 1-the first revolute pair of embodiment 1, 1H 2-the second revolute pair of embodiment 1, 1H 3-the third revolute pair of embodiment 1, 1H 4-the fourth revolute pair of embodiment 1, 1H 5-the fifth revolute pair of embodiment 1, 1H 6-the sixth revolute pair of embodiment 1, 1H 7-the seventh revolute pair of embodiment 1, 1H 8-the eighth revolute pair of embodiment 1, 1H 9-the ninth revolute pair of embodiment 1, 1H 10-the tenth revolute pair of embodiment 1,

2I-the second reference plane in example 2, α 2-the second included angle in example 2, 2O-the second intersection point of the axes of the rotation pairs in example 2, 2O 1-the center of the circle in the first folding unit in example 2, 2O 2-the center of the circle in the second folding unit in example 2, 2O 3-the center of the circle in the third folding unit in example 2, 2O 4-the center of the circle in the fourth folding unit in example 2, 2O 5-the center of the circle in the fifth folding unit in example 2, 2O 6-the center of the circle in the sixth folding unit in example 2;

2T 1-the first folding unit in example 2, 2T 2-the second folding unit in example 2; 2T 3-the third folded unit of example 2, 2T 4-the fourth folded unit of example 2, 2T 5-the fifth folded unit of example 2, 2T 6-the sixth folded unit of example 2;

2V 11-first folding unit first connection point in example 2, 2V 12-first folding unit second connection point in example 2, 2V 13-first folding unit third connection point in example 2, 2V 14-first folding unit fourth connection point in example 2, 2V 21-second folding unit first connection point in example 2, 2V 22-second folding unit second connection point in example 2, 2V 23-second folding unit third connection point in example 2, 2V 24-second folding unit fourth connection point in example 2, 2V 31-third folding unit first connection point in example 2, 2V 32-third folding unit second connection point in example 2, 2V 33-third folding unit third connection point in example 2, 2V 34-third folding unit third connection point in example 2, 2V 35-the fifth connection point of the third folding unit in example 2, 2V 36-the sixth connection point of the third folding unit in example 2, 2V 41-the first connection point of the fourth folding unit in example 2, 2V 42-the second connection point of the fourth folding unit in example 2, 2V 43-the third connection point of the fourth folding unit in example 2, 2V 44-the fourth connection point of the fourth folding unit in example 2, 2V 45-the fifth connection point of the fourth folding unit in example 2, 2V 46-the sixth connection point of the fourth folding unit in example 2, 2V 51-the first connection point of the fifth folding unit in example 2, 2V 52-the second connection point of the fifth folding unit in example 2, 2V 53-the third connection point of the fifth folding unit in example 2, 2V 54-the fourth connection point of the fifth folding unit in example 2, 2V 61-sixth folded cell first attachment point in example 2, 2V 62-sixth folded cell second attachment point in example 2, 2V 63-sixth folded cell third attachment point in example 2, 2V 64-sixth folded cell fourth attachment point in example;

2H 1-the first revolute pair in embodiment 2, 2H 2-the second revolute pair in embodiment 2, 2H 3-the third revolute pair in embodiment 2, 2H 4-the fourth revolute pair in embodiment 2, 2H 5-the fifth revolute pair in embodiment 2, 2H 6-the sixth revolute pair in embodiment 2, 2H 7-the seventh revolute pair in embodiment 2, 2H 8-the eighth revolute pair in embodiment 2, 2H 9-the ninth revolute pair in embodiment 2, 2H 10-the tenth revolute pair in embodiment 2, 2H 11-the eleventh revolute pair in embodiment 2, 2H 12-the twelfth revolute pair in embodiment 2, 2H 13-the thirteenth revolute pair in embodiment 2, and 2H 14-the fourteenth revolute pair in embodiment 2.

Detailed Description

In order to further understand the contents, features and effects of the present invention, the following embodiments are illustrated and described in detail with reference to the accompanying drawings:

example 1

As shown in fig. 1, the present embodiment provides a first embodiment of a foldable spherical structure, which includes six folding units and a first reference plane 1I. The six folding units can fold the foldable spherical structure from a space state to a plane state through relative movement among each other, and are respectively called a first folding unit 1T1, a second folding unit 1T2, a third folding unit 1T3, a fourth folding unit 1T4, a fifth folding unit 1T5 and a sixth folding unit 1T 6.

As shown in fig. 2-1 to 2-6, the six folding units are sequentially increasing in size and have a semi-circular profile. The first folding unit 1T1, the second folding unit 1T2, the fifth folding unit 1T5 and the sixth folding unit 1T6 are all provided with three connection points at the same positions, the first folding unit 1T1 is respectively provided with a first connection point 1V11, a second connection point 1V12 and a third connection point 1V13, the first connection point 1V11, the second connection point 1V12 and the third connection point 1V13 are located on the same circle, the first connection point 1V11 and the third connection point 1V13 are on the same straight line passing through the center of the circle, and an included angle between the second connection point 1V12 and the connection line between the first connection point 1V11 and the center of the circle is referred to as a first included angle α 1; the first connecting point 1V21, the second connecting point 1V22 and the third connecting point 1V23 are respectively arranged in the second folding unit 1T2, the first connecting point 1V21, the second connecting point 1V22 and the third connecting point 1V23 are located on the same circle, the first connecting point 1V21 and the third connecting point 1V23 are located on the same straight line passing through the center of the circle, and an included angle between the second connecting point 1V22, the first connecting point 1V21 and the connecting line of the center of the circle is called a first included angle α 1; the fifth folding unit 1T5 is provided with a first connection point 1V51, a second connection point 1V52 and a third connection point 1V53, the first connection point 1V51, the second connection point 1V52 and the third connection point 1V53 are located on the same circle, the first connection point 1V51 and the third connection point 1V53 are located on the same straight line passing through the center of the circle, and an included angle between the second connection point 1V52, the first connection point 1V51 and the center of the circle is called a first included angle α 1; be first tie point 1V61, second tie point 1V62 and third tie point 1V63 in the sixth folding unit 1T6 respectively, first tie point 1V61, second tie point 1V62 and third tie point 1V63 are located same circle, first tie point 1V61 and third tie point 1V63 are in same strip crossing on the straight line of circle centre, second tie point 1V62, first tie point 1V61 with the contained angle of circle centre line is called first contained angle alpha 1.

The third folding unit 1T3 and the fourth folding unit 1T4 are all provided with four connection points at the same position, the third folding unit 1T3 is respectively a first connection point 1V31, a second connection point 1V32, a third connection point 1V33 and a fourth connection point 1V34, the first connection point 1V31, the second connection point 1V32, the third connection point 1V33 and the fourth connection point 1V34 are located on the same circle, the first connection point 1V31 and the fourth connection point 1V34 are located on the same straight line passing through the circle center, and the included angles between the second connection point 1V32 and the first connection point 1V31 and the circle center are the same as the included angles between the third connection point 1V33 and the fourth connection point 1V34 and the circle center and are the same as the included angle between the first connection point α 1; be first tie point 1V41, second tie point 1V42, third tie point 1V43, fourth tie point 1V44 in the fourth folding unit 1T4 respectively, first tie point 1V41, second tie point 1V42, third tie point 1V43, fourth tie point 1V44 are located same circle, first tie point 1V41 and fourth tie point 1V44 are in the same strip on the straight line of circle centre of a circle, second tie point 1V42, first tie point 1V41 with the contained angle of circle centre of a circle line and third tie point 1V43, fourth tie point 1V44 with the contained angle of circle centre of a circle line is the same, and with first contained angle alpha 1 size is the same.

The first included angle α 1 is any angle greater than zero degrees and less than ninety degrees.

As shown in fig. 3-1 to 3-7, the first connection point 1V11 of the first folding unit 1T1 and the third connection point 1V23 of the second folding unit 1T2 are connected by the first revolute pair 1H1, the third connection point 1V13 of the first folding unit 1T1 and the first connection point 1V21 of the second folding unit 1T2 are connected by the second revolute pair 1H2, the first connection point 1V2 of the third folding unit 1T2 and the fourth connection point 1V2 of the fourth folding unit 1T2 are connected by the third revolute pair 1H2, the fourth connection point 1V2 of the third folding unit 1T2 and the first connection point 1V2 of the fourth folding unit 1T2 are connected by the fourth revolute pair 1H2, the first connection point 1V2 of the fifth folding unit 1T2 and the third connection point 1V2 of the sixth folding unit 1T2 are connected by the fifth folding unit 1H2 and the first connection point 1V2 of the sixth folding unit 1T2 and the sixth folding unit 1H2 are connected by the first connection point 1H2, the second connection point 1V12 of the first folding unit 1T1 is connected with the third connection point 1V33 of the third folding unit 1T3 through a seventh revolute pair 1H7, the second connection point 1V22 of the second folding unit 1T2 is connected with the third connection point 1V43 of the fourth folding unit 1T4 through an eighth revolute pair 1H8, the second connection point 1V32 of the third folding unit 1T3 is connected with the second connection point 1V52 of the fifth folding unit 1T5 through a ninth revolute pair 1H9, and the second connection point 1V42 of the fourth folding unit 1T4 is connected with the second connection point 1V62 of the sixth folding unit through a tenth revolute pair 1H 10;

the above rotating pairs can be assembled by parts capable of providing rotating functions, such as hinges and bearings.

As shown in fig. 4, the axes of the first revolute pair 1H1, the second revolute pair 1H2, the third revolute pair 1H3, the fourth revolute pair 1H4, the fifth revolute pair 1H5, and the sixth revolute pair 1H6 are all located on the reference plane 1I and intersect at the same point, which is called a first intersection point 1O; axes of the seventh revolute pair 1H7, the eighth revolute pair 1H8, the ninth revolute pair 1H9 and the tenth revolute pair H10 intersect at a first intersection point 1O, that is, in all folding units, a center 1O1 of a circle in the first folding unit 1T1, a center 1O2 of a circle in the second folding unit 1T2, a center 1O3 of a circle in the third folding unit 1T3, a center 1O4 of a circle in the fourth folding unit 1T4, a center 1O5 of a circle in the fifth folding unit 1T5 and a center 1O6 of a circle in the sixth folding unit 1T6 coincide with the first intersection point 1O. The axes of all the revolute pairs are intersected at one point, and the foldable spherical structure is a grid formed by a common-sphere-center spherical 4R mechanism, wherein the grid comprises four spherical 4R mechanisms which are respectively formed by a first revolute pair 1H1, a fourth revolute pair 1H4, a seventh revolute pair 1H7, an eighth revolute pair 1H8, a second revolute pair 1H2, a third revolute pair 1H3, a seventh revolute pair 1H7, an eighth revolute pair 1H8, a fourth revolute pair 1H4, a sixth revolute pair 1H6, a ninth revolute pair 1H9, a tenth revolute pair 1H10, a third revolute pair 1H3, a fifth revolute pair 1H5, a ninth revolute pair 1H9 and a tenth revolute pair 1H 10.

As shown in fig. 5-1 to 5-5, the six folding units and the connection method provided in this embodiment can form a hemispherical structure, and the folding variation is determined by the shape, size and the axis orientation of the turning pair of each folding unit. Fig. 5-1 shows one folded state of the foldable spherical structure, which is a semi-circular structure. The foldable spherical structure in this embodiment is folded and unfolded by four spherical 4R mechanisms. Fig. 5-1 to 5-5 show the folding process of the foldable spherical structure, which finally reaches the other folding state in fig. 5-5, and is a circular ring structure, which has one degree of freedom, can realize a large ratio of folding and unfolding motion, and can be used as a skeleton structure of a satellite or a contour structure of a building, etc.

It can be seen that the foldable spherical structure can achieve the folding and unfolding effect required by the present invention as long as the above constraint conditions are met, and the structural form and folding and unfolding manner are not affected by the specific structure of the folding unit, so the structure of the folding unit is not limited to the semi-circular contour, and the shape (which may be a circular contour, or a non-circular contour such as a semi-circular contour, a curve, a broken line, etc.), the size, the dimension, the material, the form of the revolute pair, etc. can be arbitrarily changed according to the practical application requirements, as long as the six folding unit dimensions are sequentially increased, the first folding unit, the second folding unit, the fifth folding unit, and the sixth folding unit are all provided with three connection points at the same positions, which are the first connection point, the second connection point, and the third connection point, in any one of the first folding unit, the second folding unit, the fifth folding unit, and the sixth folding unit, the first connecting point, the second connecting point and the third connecting point are positioned on the same circle or two or three concentric circles, the first connecting point and the third connecting point are positioned on the same straight line passing through the circle center of the circle or the concentric circle, the included angle between the first connecting point and the connecting line of the circle center of the circle or the concentric circle is alpha 1, the third folding unit and the fourth folding unit are respectively provided with four connecting points at the same position, the four connecting points are respectively the first connecting point, the second connecting point, the third connecting point and the fourth connecting point, in any folding unit of the third folding unit and the fourth folding unit, the first connecting point, the second connecting point, the third connecting point and the fourth connecting point are positioned on the same circle or two or three or four concentric circles, and the first connecting point and the fourth connecting point are positioned on the same straight line passing through the circle center of the circle or the concentric circles, the included angles of the second connecting point, the first connecting point and the circle center connecting line of the circle or the concentric circle are the same as the included angles of the third connecting point and the fourth connecting point and the circle center connecting line of the circle or the concentric circle, and are all alpha 1.

Example 2

As shown in fig. 6, the present embodiment provides a second embodiment of the foldable spherical structure, which includes six folding units and one second reference plane 2I. The six folding units can fold the foldable spherical structure from a space state to a plane state through relative movement among each other, and are respectively called a first folding unit 2T1, a second folding unit 2T2, a third folding unit 2T3, a fourth folding unit 2T4, a fifth folding unit 2T5 and a sixth folding unit 2T 6.

As shown in fig. 7-1 through 7-6, the six folding units are sequentially increasing in size and have a circular ring-shaped profile, the first folding unit 2T1, the second folding unit 2T2, the fifth folding unit 2T5 and the sixth folding unit 2T6 are all provided with four connection points at the same positions, in the first folding unit 2T1, the first connection point 2V11, the second connection point 2V12, the third connection point 2V13 and the fourth connection point 2V14 are respectively located on the same circle, the first connection point 2V11, the second connection point 2V12, the third connection point 2V13 and the fourth connection point 2V14 are located on the same circle, the first connection point 2V11 and the third connection point 2V13 are on the same straight line passing through the center of the circle, the second connection point 2V12 and the fourth connection point 2V14 are on the same straight line passing through the center of the circle, the included angle between the first connection point 2V11 and the second connection point 2V12 and the connection line of the circle center is called as a second included angle alpha 2; in the second folding unit 2T2, there are a first connection point 2V21, a second connection point 2V22, a third connection point 2V23 and a fourth connection point 2V24, respectively, where the first connection point 2V21, the second connection point 2V22, the third connection point 2V23 and the fourth connection point 2V24 are located on the same circle, the first connection point 2V21 and the third connection point 2V23 are on the same straight line passing through the center of the circle, the second connection point 2V22 and the fourth connection point 2V24 are on the same straight line passing through the center of the circle, and the included angles between the first connection point 2V21, the second connection point 2V22 and the center of the circle are referred to as a second included angle α 2; in the fifth folding unit 2T5, there are a first connection point 2V51, a second connection point 2V52, a third connection point 2V53 and a fourth connection point 2V54, respectively, where the first connection point 2V51, the second connection point 2V52, the third connection point 2V53 and the fourth connection point 2V54 are located on the same circle, the first connection point 2V51 and the third connection point 2V53 are on the same straight line passing through the center of the circle, the second connection point 2V52 and the fourth connection point 2V54 are on the same straight line passing through the center of the circle, and the included angles between the first connection point 2V51, the second connection point 2V52 and the center of the circle are referred to as a second included angle α 2; in the sixth folding unit 2T6, there are a first connection point 2V61, a second connection point 2V62, a third connection point 2V63 and a fourth connection point 2V64, respectively, where the first connection point 2V61, the second connection point 2V62, the third connection point 2V63 and the fourth connection point 2V64 are located on the same circle, the first connection point 2V61 and the third connection point 2V63 are on the same straight line passing through the center of the circle, the second connection point 2V62 and the fourth connection point 2V64 are on the same straight line passing through the center of the circle, and the included angles between the first connection point 2V61, the second connection point 2V62 and the center of the circle are referred to as a second included angle α 2.

The third folding unit 2T3 and the fourth folding unit 2T4 are all provided with six connection points at the same position, the first connection point 2V31, the second connection point 2V32, the third connection point 2V33, the fourth connection point 2V34, the fifth connection point 2V35 and the sixth connection point 2V36 are respectively arranged in the third folding unit 2T3, the first connection point 2V31, the second connection point 2V32, the third connection point 2V33, the fourth connection point 2V34, the fifth connection point 2V35 and the sixth connection point 2V 6384 are located on the same circle, the first connection point 2V31 and the fourth connection point 2V34 are located on the same straight line passing through the circle center, the second connection point 2V32 and the fifth connection point 2V35 are located on the same straight line passing through the circle center, the third connection point 2V 585 and the sixth connection point 2V36 are located on the same straight line 24 passing through the circle center, and the second connection point 582V 33 and the sixth connection point 2V36 are located on the same straight line passing through the circle center 24, The included angle between the first connecting point 2V31 and the connecting line of the circle center is the same as the included angle between the third connecting point 2V33 and the connecting line of the fourth connecting point 2V34 and the circle center, and the included angle is the same as the second included angle alpha 2; in the fourth folding unit 2T4, there are a first connection point 2V41, a second connection point 2V42, a third connection point 2V43, a fourth connection point 2V44, a fifth connection point 2V45 and a sixth connection point 2V46, respectively, the first connection point 2V41, the second connection point 2V42, the third connection point 2V43, the fourth connection point 2V44, the fifth connection point 2V45 and the sixth connection point 2V46 are located on the same circle, the first connection point 2V41 and the fourth connection point 2V44 are on the same straight line passing through the center of the circle, the second connection point 2V42 and the fifth connection point 2V45 are on the same straight line passing through the center of the circle, the third connection point 2V43 and the sixth connection point 2V46 are on the same straight line passing through the center of the circle, and included angles between the second connection point 2V42, the first connection point 2V41 and the circle, the third connection point 2V44 and the fourth connection point 43 are the same as the straight line passing through the center of the circle, and the size of the second included angle alpha 2 is the same as that of the first included angle alpha;

the second included angle α 2 is any angle greater than zero and less than ninety degrees.

As shown in fig. 8-1 to 8-7, the first connection point 2V11 of the first folding unit 2T1 and the third connection point 2V23 of the second folding unit 2T2 are connected by the first revolute pair 2H1, the third connection point 2V13 of the first folding unit 2T1 and the first connection point 2V21 of the second folding unit 2T2 are connected by the second revolute pair 2H2, the first connection point 2V2 of the third folding unit 2T2 and the fourth connection point 2V2 of the fourth folding unit 2T2 are connected by the third revolute pair 2H2, the fourth connection point 2V2 of the third folding unit 2T2 and the first connection point 2V2 of the fourth folding unit 2T2 are connected by the fourth revolute pair 2H2, the first connection point 2V2 of the fifth folding unit 2T2 and the third connection point 2V2 of the sixth folding unit 2T2 are connected by the fifth connection point 2H2 and the sixth connection point 2V2 of the fifth folding unit 2T2 and the sixth folding unit 2T2 are connected by the first connection point 2H2 and the sixth folding unit 2H 2; the second connection point 2V12 of the first folding unit 2T1 is connected with the third connection point 2V33 of the third folding unit 2T3 by a seventh revolute pair 2H7, the fourth connection point 2V14 of the first folding unit 2T1 is connected with the sixth connection point 2V36 of the third folding unit 2T3 by an eighth revolute pair 2H8, the second connection point 2V 8 of the second folding unit 2T 8 is connected with the third connection point 2V 8 of the fourth folding unit 2T 8 by a ninth revolute pair 2H8, the fourth connection point 2V 8 of the second folding unit 2T 8 is connected with the sixth connection point 2V 8 of the fourth folding unit 2T 8 by a tenth revolute pair 2H8, the second connection point 2V 8 of the third folding unit 2T 8 is connected with the second connection point 2V 8 of the fifth folding unit 2T 8 by an eleventh revolute pair 2H8, the fifth connection point 2V 8 of the third folding unit 2T 8 is connected with the fifth folding unit 2T 8 by a twelfth connection point 2H8, the second connection point 2V42 of the fourth folding unit 2T4 is connected to the second connection point 2V62 of the sixth folding unit 2T6 via a thirteenth revolute pair 2H13, and the fifth connection point 2V45 of the fourth folding unit 2T4 is connected to the fourth connection point 2V64 of the sixth folding unit 2T6 via a fourteenth revolute pair 2H 14.

As shown in fig. 9, the axes of the first revolute pair 2H1, the second revolute pair 2H2, the third revolute pair 2H3, the fourth revolute pair 2H4, the fifth revolute pair 2H5, and the sixth revolute pair 2H6 are all located on the second reference plane 2I and intersect at the same point, which is called a second intersection point 2O; the axes of the seventh revolute pair 2H7, the eighth revolute pair 2H8, the ninth revolute pair 2H9, the tenth revolute pair 2H10, the eleventh revolute pair 2H11, the twelfth revolute pair 2H12, the thirteenth revolute pair 2H13 and the fourteenth revolute pair 2H14 intersect at a second intersection point 2O, that is, in all folding units, the center 2O1 of a circle in the first folding unit 2T1, the center 2O2 of a circle in the second folding unit 2T2, the center 2O3 of a circle in the third folding unit 2T3, the center 2O4 of a circle in the fourth folding unit 2T4, the center 2O5 of a circle in the fifth folding unit 2T5 and the center 2O6 of a circle in the sixth folding unit 2T6 coincide with the second intersection point 2O. The axes of all the revolute pairs intersect at a point, the folding spherical structure is a grid formed by a concentric spherical 4R mechanism, the grid comprises 8 spherical 4R mechanisms, and the grid comprises a first revolute pair H1, a fourth revolute pair H4, a seventh revolute pair H7, a ninth revolute pair H9, a first revolute pair H1, a fourth revolute pair H4, an eighth revolute pair H8, a tenth revolute pair H10, a second revolute pair H2, a third revolute pair H3, a seventh revolute pair H7, a ninth revolute pair H9, a second revolute pair H2, a third revolute pair H2, an eighth revolute pair H2, a tenth revolute pair H2, a fourth revolute pair H2, a sixth revolute pair H2, an eleventh revolute pair H2, a thirteenth revolute pair H2, a fourth revolute pair H2, a sixth revolute pair H2, a fourteenth H2, a fourteenth H2 and a fourteenth H2, A fifth revolute pair H5, a twelfth revolute pair H12 and a fourteenth revolute pair H14.

As shown in fig. 10-1 to 10-5, the six folding units provided in this embodiment and the connection manner provided can form a spherical structure, and the folding variation is determined by the shape, size and the axis orientation of the revolute pair of each folding unit. Fig. 10-1 shows one folded state of the foldable spherical structure, which is a circular ring structure. The foldable spherical structure in this embodiment is folded and unfolded by eight spherical 4R mechanisms. Fig. 10-1 to 10-5 show the folding process of the foldable spherical structure, which finally reaches the other folded state of fig. 10-5, and is a circular ring structure having one degree of freedom, capable of realizing a large ratio of folding and unfolding motion, and can be used as a skeleton structure of a satellite or a building outline structure, etc.

It can be seen that the foldable spherical structure can achieve the folding and unfolding effect required by the present invention as long as the above constraint conditions are met, and the structural form and folding and unfolding manner are not affected by the specific structure of the folding unit, so the structure of the folding unit is not limited to the circular ring profile, and the shape (which may be a circular profile, or a non-circular profile such as a semi-circular profile, a curve, a broken line, etc.), size, dimension, material, and revolute pair form can be arbitrarily changed according to the practical application requirements, as long as the six folding unit dimensions are sequentially increased, the first folding unit, the second folding unit, the fifth folding unit, and the sixth folding unit are all provided with four connection points at the same positions, which are the first connection point, the second connection point, the third connection point, and the fourth connection point, and the first folding unit, the second folding unit, the fifth folding unit, and the fourth connection point are provided, In any folding unit of the sixth folding unit, the first connection point, the second connection point, the third connection point and the fourth connection point are located on the same circle or two or three or four concentric circles, the first connection point and the third connection point are located on the same straight line passing through the center of the circle or the concentric circle, the second connection point and the fourth connection point are located on the same straight line passing through the center of the circle or the concentric circle, and the included angle between the first connection point and the connecting line of the center of the circle or the concentric circle is alpha 2; the third folding unit and the fourth folding unit are respectively provided with six connecting points at the same positions, namely a first connecting point, a second connecting point, a third connecting point, a fourth connecting point, a fifth connecting point and a sixth connecting point, in any folding unit of the third folding unit and the fourth folding unit, the first connecting point, the second connecting point, the third connecting point, the fourth connecting point, the fifth connecting point and the sixth connecting point are positioned on the same circle or two or three or four or five or six concentric circles, the first connecting point and the fourth connecting point are positioned on the same straight line passing through the circle center or the concentric circle center, the second connecting point and the fifth connecting point are positioned on the same straight line passing through the circle or the concentric circle center, and the third connecting point and the sixth connecting point are positioned on the same straight line passing through the circle center or the concentric circle center, the included angles of the second connecting point, the first connecting point and the circle center connecting line of the circle or the concentric circle are the same as the included angles of the third connecting point and the fourth connecting point and the circle center connecting line of the circle or the concentric circle, and are all alpha 2.

In conclusion, the foldable spherical structure provided by the invention has a single degree of freedom and a large folding and unfolding ratio, so that the foldable spherical structure has the advantages of simplicity in installation, convenience in operation, easiness in transportation and the like, and is particularly suitable for application in the fields of aerospace and the like.

Although the preferred embodiments of the present invention have been described with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and those skilled in the art can make various changes and modifications within the spirit and scope of the present invention without departing from the spirit and scope of the appended claims.

Claims

1. A foldable spherical structure, comprising six folding units capable of folding the foldable spherical structure from a spatial state into a planar state by relative movement between each other, and a first reference plane; the sizes of the six folding units are sequentially increased in an increasing mode and respectively form a first folding unit, a second folding unit, a third folding unit, a fourth folding unit, a fifth folding unit and a sixth folding unit;

the first folding unit, the second folding unit, the fifth folding unit and the sixth folding unit are all provided with three connecting points at the same positions, namely a first connecting point, a second connecting point and a third connecting point; in any folding unit of the first folding unit, the second folding unit, the fifth folding unit and the sixth folding unit, the first connection point, the second connection point and the third connection point are located on the same circle or two or three concentric circles, the first connection point and the third connection point are located on the same straight line passing through the circle center or the concentric circle center, an included angle between the first connection point and the circle center or the concentric circle center is called as a first included angle, and the first included angle is any angle larger than zero degrees and smaller than ninety degrees;

2. The spherical collapsible structure as recited in claim 1 wherein said revolute pair is a hinge or a bearing.

3. A spherical collapsible structure according to claim 1, characterised in that the folding unit has a circular or semi-circular or curved or broken line profile.

4. A foldable spherical structure, comprising six folding units capable of folding the foldable spherical structure from a spatial state into a planar state by relative movement between each other, and a second reference plane; the sizes of the six folding units are sequentially increased in an increasing mode and respectively form a first folding unit, a second folding unit, a third folding unit, a fourth folding unit, a fifth folding unit and a sixth folding unit;

the first folding unit, the second folding unit, the fifth folding unit and the sixth folding unit are all provided with four connecting points at the same positions, namely a first connecting point, a second connecting point, a third connecting point and a fourth connecting point; in any folding unit of the first folding unit, the second folding unit, the fifth folding unit and the sixth folding unit, the first connection point, the second connection point, the third connection point and the fourth connection point are located on the same circle or two or three or four concentric circles, the first connection point and the third connection point are on the same straight line passing through the circle center or the concentric circle center, the second connection point and the fourth connection point are on the same straight line passing through the circle center or the concentric circle center, the included angle between the first connection point and the circle center or the concentric circle center is called as a second included angle, and the second included angle is any angle larger than zero degree and smaller than ninety degrees;

5. A spherical collapsible structure according to claim 4, characterised in that the revolute pair is a hinge or a bearing.

6. A spherical collapsible structure according to claim 4, characterised in that the folding units have a circular or semi-circular or curved or broken line profile.