A single degree of freedom three-spherical four-bar link mechanism

Abstract

The application relates to a single-degree-of-freedom three-spherical-surface four-bar ring mechanism, which comprises three spherical-surface four-bar units, namely a first spherical-surface four-bar unit, a second spherical-surface four-bar unit and a third spherical-surface four-bar unit; each spherical-surface four-bar unit comprises four rods which are sequentially connected in a head-to-tail mode and are rotationally connected at the connecting positions; a connecting joint is arranged in the middle of two adjacent rods; the first spherical-surface four-bar unit is rotationally connected with one connecting joint of the second spherical-surface four-bar unit and the third spherical-surface four-bar unit through two connecting joints of the first spherical-surface four-bar unit, and the other connecting joint of the second spherical-surface four-bar unit is rotationally connected with the other connecting joint of the third spherical-surface four-bar unit. The single-degree-of-freedom three-spherical-surface four-bar ring mechanism has the characteristics of single degree of freedom, one plane, one umbrella-shaped bundle, reciprocating folding and unfolding and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of space folding, aviation, aerospace, folding tent, etc., and particularly relates to a single-degree-of-freedom three-spherical-surface four-bar link mechanism. BACKGROUND

[0002] Linkage structures are often used in aviation, aerospace, outdoor devices, etc., such as the folding and unfolding of solar panels and the folding and building of tents. A single-degree-of-freedom spherical surface turnover mechanism is disclosed in Chinese patent application No. CN202210364243.8. The mechanism can realize turnover motion at multiple angles in space while ensuring that it has one degree of freedom. However, the motion mode of the mechanism is relatively single, it cannot be folded into a bundle, it occupies a large space when stored, and it cannot be unfolded into a plane. SUMMARY

[0003] In order to overcome the problems existing in the prior art, the application provides a single-degree-of-freedom three-spherical-surface four-bar link mechanism, which has the characteristics of single degree of freedom, can be unfolded into a plane, folded into a bundle like an umbrella, and has reciprocating folding motion, while maintaining the advantages of folding.

[0004] The technical scheme for solving the above problems is as follows: a single-degree-of-freedom three-spherical-surface four-bar link mechanism, characterized by:

[0005] The mechanism comprises three spherical surface four-bar units: a first spherical surface four-bar unit, a second spherical surface four-bar unit, and a third spherical surface four-bar unit.

[0006] Each spherical surface four-bar unit comprises four rods, which are connected end to end in sequence and are rotationally connected at the connection points; and a connection joint is arranged at the middle of two adjacent rods.

[0007] The first spherical surface four-bar unit is connected to one connection joint of the second spherical surface four-bar unit and the third spherical surface four-bar unit through its two connection joints and realizes rotational connection, and the other connection joint of the second spherical surface four-bar unit and the other connection joint of the third spherical surface four-bar unit are connected and realize rotational connection.

[0008] Further, the first spherical surface four-bar unit, the second spherical surface four-bar unit, and the third spherical surface four-bar unit are the same in structure.

[0009] Further, the first spherical surface four-bar unit comprises four rods of the same length: a first rod, a second rod, a third rod, and a fourth rod; each rod is provided with a hole for connection at each end, and the axes of the two holes intersect at a point; adjacent two rods are rotationally connected by inserting a pin shaft through the corresponding holes.

[0010] Furthermore, the two connecting joints of the aforementioned first spherical four-bar unit are the first connecting joint and the second connecting joint, which are respectively located in the middle of the first bar and the fourth bar.

[0011] Furthermore, both the first and second connecting joints are circular tubes, and the axis of the hole inside the circular tube is parallel to the length direction of the rod in which it is located.

[0012] Furthermore, the distances from the upper bottom surface of the first connecting joint to the holes at both ends of the first rod are equal.

[0013] Furthermore, the distances from the bottom surface of the second connecting joint to the holes at both ends of the fourth member are equal.

[0014] Furthermore, the two joints mentioned above are connected by a pin.

[0015] Advantages of this invention:

[0016] This invention proposes a single-degree-of-freedom three-spherical four-bar linkage mechanism, which not only possesses the characteristics of a single degree of freedom, but also features the ability to unfold into a plane, fold into an umbrella-shaped bundle, and exhibit reciprocating unfolding motion. This mechanism connects three spherical four-bar units in a loop, and only includes revolute joints, making the structure relatively simple and easy to process and manufacture. Based on the unfolding characteristics of this mechanism, it can be further applied to unfolding tents or aerospace fields, etc. Attached Figure Description

[0017] Figure 1 This is a three-dimensional view of the single-degree-of-freedom three-spherical four-bar linkage proposed in this invention.

[0018] Figure 2 for Figure 1 3D diagram of a mid-spherical four-bar element;

[0019] Figure 3 for Figure 1 Three-dimensional end members of the mid-spherical four-bar unit Figure 1 ;

[0020] Figure 4 for Figure 1 Three-dimensional end members of the mid-spherical four-bar unit Figure 2 ;

[0021] Figure 5 for Figure 1 Three-dimensional connection of the mid-spherical four-bar unit Figure 1 ;

[0022] Figure 6 for Figure 1 Three-dimensional connection of the mid-spherical four-bar unit Figure 2 ;

[0023] Figure 7 A schematic diagram of the reciprocating folding and unfolding motion of the single degree of freedom three spherical surface four-bar loop mechanism proposed in the present application.

[0024] Reference Signs:

[0025] First spherical surface four-bar unit A, second spherical surface four-bar unit B, third spherical surface four-bar unit C,

[0026] First link A-1, second link A-2, third link A-3, fourth link A-4, fifth link B-1, sixth link B-2, seventh link B-3, eighth link B-4, ninth link C-1, tenth link C-2, eleventh link C-3, twelfth link C-4,

[0027] First hole A-1-1, second hole A-1-2, third hole A-2-1, fourth hole A-2-2, fifth hole A-3-1, sixth hole A-3-2, seventh hole A-4-1, eighth hole A-4-2,

[0028] First connecting joint A-1-3, second connecting joint A-4-3, third connecting joint B-1-3, fourth connecting joint B-4-3, fifth connecting joint C-1-3, sixth connecting joint C-4-3. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application.

[0030] Reference Figure 1 The present application proposes a single degree of freedom three spherical surface four-bar loop mechanism, which comprises a first spherical surface four-bar unit A, a second spherical surface four-bar unit B and a third spherical surface four-bar unit C which are of the same structure.

[0031] Reference Figure 1 and Figure 2, the first spherical four-bar unit A includes a first bar A-1, a second bar A-2, a third bar A-3 and a fourth bar A-4; the second spherical four-bar unit B includes a fifth bar B-1, a sixth bar B-2, a seventh bar B-3 and an eighth bar B-4; the third spherical four-bar unit C includes a ninth bar C-1, a tenth bar C-2, an eleventh bar C-3 and a twelfth bar C-4, and the lengths and thicknesses of the bars are all the same.

[0032] The four bars of each spherical four-bar unit are sequentially connected end to end, and the connection positions are rotationally connected; and a connecting joint is arranged at the middle of two adjacent bars. The first spherical four-bar unit A is rotationally connected with one connecting joint of the second spherical four-bar unit B and the third spherical four-bar unit C through two connecting joints of the first spherical four-bar unit A, and the other connecting joint of the second spherical four-bar unit B is rotationally connected with the other connecting joint of the third spherical four-bar unit C. The single-degree-of-freedom three-spherical four-bar loop mechanism can be unfolded into a plane, folded into an umbrella-shaped bundle, and has the characteristics of reciprocating folding and unfolding.

[0033] The first spherical four-bar unit A, the second spherical four-bar unit B and the third spherical four-bar unit C all have the same structure, and the first spherical four-bar unit A is taken as an example for detailed description:

[0034] Referring to Figure 1 , in the first spherical four-bar unit A, the middle of the first bar A-1 is provided with a first connecting joint A-1-3, the middle of the fourth bar A-4 is provided with a second connecting joint A-4-3, the fifth bar B-1 is provided with a third connecting joint B-1-3, the eighth bar B-4 is provided with a fourth connecting joint B-4-3, the ninth bar C-1 is provided with a fifth connecting joint C-1-3, and the twelfth bar C-4 is provided with a sixth connecting joint C-4-3. The first spherical four-bar unit A is rotationally connected with the second spherical four-bar unit B through the second connecting joint A-4-3 of the fourth bar A-4 and the third connecting joint B-1-3 of the fifth bar B-1, the second spherical four-bar unit B is rotationally connected with the third spherical four-bar unit C through the fourth connecting joint B-4-3 of the eighth bar B-4 and the fifth connecting joint C-1-3 of the ninth bar C-1, and the third spherical four-bar unit C is rotationally connected with the first spherical four-bar unit A through the sixth connecting joint C-4-3 of the twelfth bar C-4 and the first connecting joint A-1-3 of the first bar A-1. The two connected joints are rotationally connected through a pin shaft.

[0035] As Figure 2As shown, the first rod A-1 of the first spherical four-bar unit A is rotatably connected with the second rod A-2 and the fourth rod A-4, the second rod A-2 is rotatably connected with the third rod A-3, and the third rod A-3 is rotatably connected with the fourth rod A-4. The first hole A-1-1 of the first rod A-1 is rotatably connected with the eighth hole A-4-2 of the fourth rod A-4 by inserting a pin, the second hole A-1-2 of the first rod A-1 is rotatably connected with the third hole A-2-1 of the second rod A-2 by inserting a pin, the fourth hole A-2-2 of the second rod A-2 is rotatably connected with the fifth hole A-3-1 of the third rod A-3 by inserting a pin, and the sixth hole A-3-2 of the third rod A-3 is rotatably connected with the seventh hole A-4-1 of the fourth rod A-4 by inserting a pin. The axes of all the holes of the first rod A-1, the second rod A-2, the third rod A-3, and the fourth rod A-4 intersect at a point in space, forming a spherical four-bar mechanism.

[0036] As shown in Figure 3 and Figure 4 As shown, the second rod A-2 and the third rod A-3 are identical, and each includes the third hole A-2-1, the fourth hole A-2-2, the fifth hole A-3-1, and the sixth hole A-3-2. The angle between the third hole A-2-1 and the fourth hole A-2-2 is equal to the angle between the fifth hole A-3-1 and the sixth hole A-3-2, and the offset of the holes is greater than or equal to the radius of the holes.

[0037] As shown in Figure 5 As shown, the first rod A-1 includes the first hole A-1-1, the second hole A-1-2, and the first connecting joint A-1-3. The axes of the first hole A-1-1 and the second hole A-1-2 intersect at a point, the first connecting joint is a circular tube, the axis of the first connecting joint A-1-3 is parallel to the plane in which the joint is located, and the distance from the upper bottom surface of the first connecting joint A-1-3 to the first hole A-1-1 and the second hole A-1-2 is equal.

[0038] As shown in Figure 6 As shown, the fourth rod A-4 includes the seventh hole A-4-1, the eighth hole A-4-2, and the second connecting joint A-4-3. The axes of the seventh hole A-4-1 and the eighth hole A-4-2 intersect at a point, the second connecting joint is a circular tube, the axis of the second connecting joint A-4-3 is parallel to the plane in which the joint is located, and the distance from the lower bottom surface of the second connecting joint A-4-3 to the seventh hole A-4-1 and the eighth hole A-4-2 is equal. The angle between the axes of the first hole A-1-1 and the second hole A-1-2 of the first rod A-1 is equal to the angle between the axes of the seventh hole A-4-1 and the eighth hole A-4-2 of the fourth rod A-4.

[0039] The second spherical four-bar unit B, the third spherical four-bar unit C and the first spherical four-bar unit A are identical in shape, mechanical structure and assembly mode, and details are not repeated here.

[0040] Through the above connection, the assembly of the first to third spherical four-bar units is completed.

[0041] As shown in Figure 7 The single-degree-of-freedom three-spherical four-bar ring mechanism has the characteristics of single degree of freedom, unfolding into a plane, folding into a bundle, reciprocating folding and unfolding movement, and simple structure. The single-degree-of-freedom three-spherical four-bar ring mechanism only has rotary pairs, has the characteristics of single degree of freedom, unfolds into a plane, folds into a bundle, has up-and-down surging movement, and has a simple structure. The single-degree-of-freedom three-spherical four-bar ring mechanism connects three spherical four-bar units in a ring, only contains rotary pairs, and has a relatively simple structure, easy processing and manufacturing. Based on the folding and unfolding characteristics of the mechanism, the mechanism can be further applied to folding and unfolding tents or aerospace and aviation fields.

[0042] The above description is only an embodiment of the present application, and does not limit the protection scope of the present application. Any equivalent structure or equivalent flow transformation based on the content of the specification and drawings, or direct or indirect application in other related system fields, is also included in the protection scope of the present application.

Claims

1. A single-degree-of-freedom three-spherical four-bar linkage, characterized in that: It includes three spherical four-bar units: the first spherical four-bar unit, the second spherical four-bar unit, and the third spherical four-bar unit; the first spherical four-bar unit, the second spherical four-bar unit, and the third spherical four-bar unit have the same structure; Each spherical four-bar unit consists of four bars, which are connected end to end in sequence, and the connection is a rotatable joint; a connecting joint is provided in the middle of two adjacent bars; The first spherical four-bar unit is connected to one of the connecting joints of the second and third spherical four-bar units through its two connecting joints, and the two connecting joints of the second and third spherical four-bar units are connected to each other ... The first spherical four-bar unit includes four bars of the same length: a first bar, a second bar, a third bar, and a fourth bar; each bar has a hole at both ends for connection, and the axes of the two holes intersect at a point; adjacent bars are rotatably connected by inserting a pin through their corresponding holes.

2. The single-degree-of-freedom three-spherical four-bar linkage according to claim 1, characterized in that: The first spherical four-bar unit has two connecting joints: a first connecting joint and a second connecting joint, which are respectively located in the middle of the first bar and the fourth bar.

3. The single-degree-of-freedom three-spherical four-bar linkage according to claim 2, characterized in that: Both the first and second connecting joints are circular tubes, and the axis of the hole inside the circular tube is parallel to the length direction of the rod in which it is located.

4. The single-degree-of-freedom three-spherical four-bar linkage according to claim 3, characterized in that: The distances from the top surface of the first connecting joint to the holes at both ends of the first rod are equal.

5. A single-degree-of-freedom three-spherical four-bar linkage mechanism according to claim 4, characterized in that: The distances from the bottom surface of the second connecting joint to the holes at both ends of the fourth member are equal.

6. A single-degree-of-freedom three-spherical four-bar linkage mechanism according to claim 5, characterized in that: The two joints are connected by a pin.

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