A root locking mechanism applied to a space stretching arm

Abstract

The application discloses a root locking mechanism applied to a space stretching arm, which is used for locking a supporting disc and a sleeve of the space stretching arm, and the supporting disc is perpendicular to the axial direction of the sleeve, and the root locking mechanism is characterized in that the root locking mechanism comprises a locking mechanism unit, an anti-overturning mechanism assembly and a structural locking groove on the inner wall of the sleeve, wherein the four anti-overturning mechanism assemblies are correspondingly installed on the four locking mechanism units, one end of each anti-overturning mechanism assembly is in contact with the inner wall of the sleeve, and the four anti-overturning mechanism assemblies provide a supporting action for the root locking mechanism; the bottom ends of the four locking mechanism units are correspondingly installed on four corners of the supporting disc; and the inner wall of the sleeve is uniformly provided with the four structural locking grooves which are respectively matched with the upper ends of the four locking mechanism units to be locked. The root locking mechanism has the advantages of compact structure, stable and reliable working process, high locking stiffness, convenient unlocking, reusability and the like.

Description

Technical Field

[0001] This invention relates to a root locking mechanism for a space extension arm, belonging to the field of space machinery technology. Background Technology

[0002] With the development of the aerospace industry, higher requirements have been placed on the reliability of the space extension arm system to meet the needs of various payload detection. The root locking mechanism is used to position and lock the root of the space extension arm after it is fully deployed, ensuring its structural rigidity and accuracy, and playing a crucial role in the reliable and stable operation of the space extension arm system.

[0003] Currently, the mainstream root locking method is the pin-type locking mechanism. The pin-type locking mechanism mainly utilizes the positional cooperation between the positioning pin and the positioning hole to achieve positioning and locking between the last deployable unit of the extendable arm and the drive mechanism, as seen in the publications such as "A Locking Mechanism for a Total Spaceborne Deployable Antenna Extendable Arm" (CN201410119950.6) by Xiao Meng of Xi'an University of Electronic Science and Technology and "Telescopic Link Locking Mechanism" (CN200810064202.7) by Deng Zongquan of Harbin Institute of Technology. The success of the pin-type locking mechanism is constrained by the positional relationship between the positioning pin and the positioning hole, and the locking force depends entirely on the preload of the compression spring. It is generally used in scenarios where high precision and rigidity requirements are not high. However, the root locking mechanism used in space extendable arms requires high rigidity, high precision, and high reliability, which the pin-type locking mechanism cannot meet. Summary of the Invention

[0004] The technical problem solved by the present invention is to overcome the shortcomings of the prior art and provide a root locking mechanism for a space extension arm, which has the advantages of compact structure, stable and reliable operation, high locking rigidity, convenient unlocking and reusability.

[0005] The technical solution of this invention is: a root locking mechanism for a space extension arm, used to lock the support plate and sleeve of the space extension arm, wherein the support plate is perpendicular to the axial direction of the sleeve; the root locking mechanism includes a locking mechanism unit, an anti-tipping mechanism assembly, and a structural locking groove on the inner wall of the sleeve, wherein:

[0006] The four anti-tipping mechanism components are installed one-to-one on the four locking mechanism units, with one end in contact with the inner wall of the sleeve to provide support for the root locking mechanism.

[0007] The bottom ends of the four locking mechanism units are installed one-to-one with the four corners of the support plate;

[0008] The inner wall of the sleeve has four structural locking grooves, which are respectively engaged with the upper ends of four locking mechanism units for locking.

[0009] Preferably, the root locking mechanism unit includes: a frame, a lifting handle, a locking spring cylinder, a spring cover, a locking spring, a return spring, a return spring cover, a slide rod, a short connecting rod, and a long connecting rod; wherein:

[0010] The frame is the housing of the root locking mechanism unit, and the bottom is connected to the support plate. A protruding structure is provided at one end of the upper part of the frame, and a hole is provided on it. The hole is used to connect one end of the short connecting rod to form a revolute joint connection. The other end of the short connecting rod is connected to one end of the long connecting rod, and the other end of the long connecting rod is connected to one end of the slide rod. The other end of the slide rod passes through the shaft hole in the middle of the frame to form a sliding joint. The slide rod, long connecting rod, short connecting rod and frame are combined to form a four-bar linkage mechanism.

[0011] The outer diameter of the slide rod gradually decreases in a stepped manner from one end connecting the long connecting rod to the other end; the locking spring cylinder is located inside the frame and is sleeved on the larger diameter end of the slide rod; the spring cover is rigidly fixed in the middle position of the slide rod and moves with the slide rod during operation; the locking spring is sleeved on the slide rod and is located between the spring cover and the locking spring cylinder, and the spring cover and the locking spring cylinder work together to compress the locking spring; the return spring cover is located inside the frame and is sleeved on the smaller diameter end of the slide rod; the return spring is sleeved on the slide rod and is located between the spring cover and the return spring cover, and the spring cover and the return spring cover work together to compress the return spring;

[0012] The lifting handle is S-shaped and located on the upper part of the frame. One end of it is rigidly connected to the outside of the locking spring cylinder, and a secondary roller is installed on it. The other end rests on the upper end of the frame, and a main roller is installed on the lower surface of this end. The main roller and the secondary roller constrain the degree of freedom of the lifting handle, so that it can only perform linear motion.

[0013] Preferably, the anti-tipping mechanism assembly includes: an anti-tipping rod, a slider, a slider cover, a slider rod, an anti-tipping spring, an anti-tipping spring cover, and an anti-tipping spring sleeve; wherein:

[0014] One end of the anti-tipping rod is connected to the middle of the frame, and the upper part of the other end is equipped with an anti-tipping spring sleeve, while the lower part has a baffle structure integrally formed with the anti-tipping rod. The anti-tipping spring cover is located inside the anti-tipping spring sleeve, and the anti-tipping spring is located between the anti-tipping spring cover and the baffle structure of the anti-tipping rod. The lower end of the slider rod passes through the through hole on the upper end face of the anti-tipping spring sleeve, the corresponding through hole on the anti-tipping spring cover, the anti-tipping spring, and the corresponding through hole on the baffle structure of the anti-tipping rod. The slider cover is located at the upper end of the slider rod, and the slider and the slider cover are connected by a ball joint, which allows free rolling at the end of the slider rod.

[0015] Preferably, during operation, the anti-tipping mechanism component ensures that the sliding ball remains in contact with the inner cylindrical sidewall of the sleeve and rolls freely, providing support for the root locking mechanism.

[0016] Preferably, the inner wall of the sleeve is provided with a positioning structure that cooperates with the protrusion structure provided at one end of the upper part of the frame, and the corresponding structural locking groove is provided on a straight line parallel to the axial direction of the sleeve.

[0017] Preferably, when the structural locking groove engages with the upper end of the locking mechanism unit for locking:

[0018] An external pulling force F acts on the lifting handle, and the root locking mechanism moves in the direction of the pulling force F. When the protruding structure at one end of the upper part of the frame is completely in contact with the positioning structure on the inner wall of the sleeve, the root locking mechanism unit stops moving. The return spring and the locking spring are compressed in sequence, which drives the slide rod to move in the direction of the pulling force, and then drives the entire four-bar linkage to start moving. The short link gradually changes to a horizontal state, and the long link gradually changes to a vertical state. Finally, the upper end of the long link is in complete contact with the sleeve locking groove, and the locking is completed.

[0019] Preferably, the root locking mechanism unlocks automatically after the external pulling force is released, specifically as follows:

[0020] The return spring and locking spring are no longer compressed by the external pulling force and gradually return to their original length on their own; under the action of the elastic force, the slide bar moves in the opposite direction to the locking stage, thereby driving the entire four-bar linkage to begin unlocking, that is, the long link separates from the sleeve lock groove, and the unlocking is completed.

[0021] Preferably, the distance between the positioning structure on the inner wall of the sleeve and the corresponding structural locking groove is determined based on the dimensions of the four-bar linkage and the compression of the return spring and the locking spring.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) The present invention utilizes unidirectional preload to achieve axial, radial and circumferential full positioning and locking functions between the extension arm and the sleeve, and utilizes the anti-overturning component to provide elastic support for the mechanism to achieve automatic posture adjustment of the mechanism and achieve high-precision locking function.

[0024] (2) The present invention utilizes the lever effect of the four-bar linkage to amplify the locking force, thereby fulfilling the requirement of high-rigidity locking;

[0025] (3) The present invention utilizes a combination of multiple springs to simultaneously maintain the preload of the mechanism and self-reset the mechanism, thus enabling the mechanism to be reused.

[0026] (4) The present invention utilizes a purely mechanical method to realize the locking force self-amplification, full positioning locking, and mechanism self-reset functions of the locking mechanism, thereby enhancing its wide adaptability in the task of locking the space extension arm. Attached Figure Description

[0027] Figure 1 This is a connection diagram of the root locking mechanism unit and the anti-tipping mechanism assembly of the present invention;

[0028] Figure 2 Diagram showing the connection between the root locking mechanism unit and the support plate;

[0029] Figure 3 This is a diagram showing the connection between the sleeve and the locking groove of the present invention;

[0030] Figure 4 The diagram shows the root locking mechanism and sleeve fitting together according to the present invention; wherein, (a) is a front view of the root locking mechanism and sleeve fitting together, and (b) is a cross-sectional view of the root locking mechanism and sleeve fitting together.

[0031] Figure 5 This is a diagram showing the composition of the locking mechanism unit of the present invention;

[0032] Figure 6 This is a schematic diagram of the anti-tipping component of the present invention; wherein, (a) is a composition diagram of the anti-tipping component, and (b) is a diagram showing the contact relationship between the anti-tipping component and the sleeve;

[0033] Figure 7 This is a schematic diagram of the four working stages of the root locking mechanism of the present invention, wherein (a) is the initial stage, (b) is the positioning stage, (c) is the locking stage, and (d) is the unlocking stage. Detailed Implementation

[0034] This invention proposes a root locking mechanism based on a four-bar linkage. This mechanism has a compact structure, stable and reliable operation, high locking stiffness, convenient unlocking, and reusability. Furthermore, it features a locking force amplification function, making it widely adaptable to locking spatial extension arms. Specifically:

[0035] A root locking mechanism for a space extension arm is disclosed. The root locking mechanism locks the support plate 3 and sleeve 4 of the space extension arm. The support plate 3 is perpendicular to the axial direction of the sleeve 4. The root locking mechanism mainly consists of a locking mechanism unit 1, an anti-tipping mechanism assembly 2, and a structural locking groove 401 on the inner wall of the sleeve 4. The anti-tipping mechanism assembly 2 is fastened to the locking mechanism unit 1 with screws. Figure 1 As shown, four locking mechanism units 1 are evenly distributed and mounted on a support plate by bolts, forming a complete root locking mechanism, as shown. Figure 2 As shown. Four structural locking grooves 401 are evenly distributed on the sleeve 4. The structural locking grooves 401 are connected to the sleeve by screws, as shown. Figure 3 As shown. Ultimately, the root locking mechanism utilizes the engaging connection between the locking mechanism unit 1 and the structural locking groove 401, as... Figure 4 As shown in (a) and (b), the root locking mechanism is locked relative to the sleeve 4.

[0036] Each root locking mechanism unit 1 includes a frame 101, a lifting handle 102, a locking spring cylinder 103, a spring cover 104, a locking spring 105, a return spring 106, a return spring cover 107, a slide bar 108, a short connecting rod 109, and a long connecting rod 110, such as Figure 5 As shown. The frame 101 serves as the housing for the root locking mechanism unit 1, providing support and protection for the mechanism. The outer diameter of the slide rod 108 decreases progressively from one end to the other in a stepped manner. The slide rod 108 forms a sliding joint with the hole on the frame 101 through a shaft-hole fit. The large-diameter end of the slide rod 108, the long connecting rod 110, and the short connecting rod 109 are connected end-to-end through shaft-hole fits to form a rotating joint. A protruding structure with a hole is provided at one end of the upper part of the frame 101, and the other end of the short connecting rod 109 is connected to the hole on the frame 101 through a rotating joint. Finally, the slide rod 108, the long connecting rod 110, the short connecting rod 109, and the frame 101 combine to form a four-bar linkage.

[0037] The locking spring cylinder 103 is sleeved on the slide rod 108 and located in the middle of the frame of the machine frame 101. The spring cover 104 is rigidly fixed to the middle position of the slide rod 108 by means of a nut and moves with the slide rod during operation. The locking spring 105 is sleeved on the slide rod 108 and located between the spring cover 104 and the locking spring cylinder 103. The spring cover 104 and the locking spring cylinder 103 work together to compress the locking spring 105. The return spring 106 is also sleeved on the slide rod 108 and located between the spring cover 104 and the return spring cover 107. The spring cover 104 and the return spring cover 107 work together to compress the return spring 106.

[0038] The lifting handle 102 is S-shaped and located on the upper part of the frame 101. One end of the lifting handle 102 is rigidly connected to the outside of the locking spring cylinder 103 by screws, and the upper and lower surfaces of the other end are provided with main roller 111 and auxiliary roller 112 to constrain its degree of freedom, so that the lifting handle 102 can only perform linear motion.

[0039] The anti-tipping mechanism assembly 2 includes an anti-tipping rod 201, a slider 202, a slider cover 203, a slider rod 204, an anti-tipping spring 205, an anti-tipping spring cover 206, and an anti-tipping spring sleeve 207. One end of the anti-tipping rod 201 is connected to the middle of the frame 101, such as... Figure 6As shown in (a). An anti-tipping spring sleeve 207 is installed on the upper part of the other end of the anti-tipping rod 201. The anti-tipping spring cover 206 is located inside the anti-tipping spring sleeve 207, and the anti-tipping spring 205 is located between the anti-tipping spring cover 206 and the anti-tipping rod 201 itself. The lower end of the slider 204 passes through the through hole on the upper end face of the anti-tipping spring sleeve 207, the corresponding through hole on the anti-tipping spring cover 206, the anti-tipping spring 205, and the corresponding through hole on the anti-tipping rod 201 itself in sequence; the slider cover 203 is located at the upper end of the slider 204, and the slider 202 and the slider cover 203 are connected by a ball joint, which can realize free rolling at the end of the slider. During the operation of the anti-tipping mechanism component 2, the slider 202 is always in contact with the inner cylindrical side wall of the sleeve 4 and rolls freely, providing support for the root locking mechanism, such as Figure 6 As shown in (b).

[0040] The inner wall of the sleeve 4 is provided with a positioning structure that cooperates with the protrusion structure provided at one end of the upper part of the frame 101, and the corresponding structural locking groove 401 is provided on a straight line parallel to the axial direction of the sleeve 4.

[0041] The distance between the positioning structure on the inner wall of the sleeve 4 and the corresponding structural locking groove 401 is determined based on the dimensions of the four-bar linkage and the compression of the return spring 106 and the locking spring 105.

[0042] The following is combined with Figure 7 The present invention will be further described below.

[0043] (1) In the initial stage of the root locking mechanism's operation, such as Figure 7 As shown in (a): An external pulling force F acts on the lifting handle 102. The lifting handle 102 pulls up the locking spring cylinder 103, further transmitting the external force to the locking spring 105, spring cap 104, and return spring 106, ultimately transmitting the force to the frame 101. However, since there is a gap between the root locking mechanism and the sleeve 4 in the initial state (i.e., the gap L≥0), the root locking mechanism will move in the direction of the pulling force F during this stage until L=0.

[0044] (2) During the positioning stage of the root locking mechanism, such as Figure 7(b) shows that the root locking mechanism is fully engaged with the sleeve 4, i.e., the gap L = 0. The external pulling force F continues to act on the lifting handle 102, transmitting the force to the frame 101 in the same way as in the initial stage. However, since the frame 101 of the root locking mechanism is fully engaged with the sleeve 4, the frame 101 of the root locking mechanism will no longer move, and the locking spring 105 and the return spring 106 begin to be compressed. Since the preload of the return spring 106 in the mechanism is less than the preload of the locking spring 105, in this stage, as the external pulling force F acts, the return spring 106 is compressed first, and the spring cover 104 can then move in the direction of the pulling force. At the same time, since the spring cover 104 and the slide rod 108 are rigidly connected, in this stage, the slide rod 108 finally moves in the direction of the pulling force, thereby driving the entire four-bar linkage to start moving. The short connecting rod 109 gradually changes to a horizontal state, and the long connecting rod 110 gradually changes to a vertical state until the long connecting rod 110 contacts the sleeve locking groove 401 and begins to lock.

[0045] (3) During the locking phase of the root locking mechanism, such as Figure 7 As shown in (c): The external pulling force F continues to pull the lifting handle 102, and in the same force transmission method as in the positioning stage, it continues to compress the return spring 106. However, since the upper end of the long connecting rod 110 in the root locking mechanism is in complete contact with the sleeve locking groove 401, the four-bar linkage is locked, causing the slide rod 108 of the root locking mechanism and the spring cover 104 rigidly connected to it to stop moving. At this time, the return spring 106 stops being compressed, and the locking spring 105 begins to be compressed until the locking spring 105 reaches the maximum compression position, completing the locking process.

[0046] Once the root locking mechanism has locked in place, it amplifies the external pulling force, specifically:

[0047] In the four-bar linkage formed by the slide bar 108, long connecting rod 110, short connecting rod 109, and frame 101, short connecting rod 109 serves as the fulcrum. The elastic force acting on the slide bar 108 is amplified by the lever action of short connecting rod 109 and long connecting rod 110, achieving high preload locking between the end of long connecting rod 110 and sleeve locking groove 401, thus completing the locking process.

[0048] (4) During the unlocking phase of the root locking mechanism, such as Figure 7As shown in (d): After locking is completed, the root locking mechanism begins to unlock autonomously after the external pulling force is released. The return spring 106 and the locking spring 105 are no longer compressed by the external pulling force and gradually return to their original length autonomously. The spring cap 104 of the root locking mechanism and the slide rod 108 rigidly connected to it move in the opposite direction to the locking stage under the action of the elastic force, thereby driving the entire four-bar linkage to begin unlocking, that is, the long connecting rod 110 separates from the sleeve locking groove 401, completing the unlocking.

[0049] Example:

[0050] The root locking mechanism weighs 2.5 kg, the anti-tipping spring has a supporting force of 104 N, the short connecting rod is 17 mm long, the long connecting rod is 60 mm long, and the locking force is magnified by a factor of 4 compared to the preload force. Locking is achieved within a 1200 mm extension arm sleeve. In the locked state, the locking spring has a locking force of 1890 N, and the return spring has a return force of 157 N.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Any modifications or equivalent substitutions to the solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and should be included within the claims of the present invention.

[0052] The root locking mechanism of this invention utilizes the elastic potential energy generated by the different deformations of two springs to achieve the locking and resetting functions of the mechanism. In the locked state, the locking spring deforms and stores elastic potential energy, which is used to provide the preload force in the locked state. The preload force generated by the locking spring is amplified by the four-bar linkage and applied to the locking groove assembly. In the resetting state, the elastic potential energy stored in the resetting spring in the locked state is released, providing the resetting force required for the resetting operation, so that the mechanism self-resets to the initial position without external force, ready to repeat the locking action. During the movement of the root locking mechanism with the extension arm, the rolling metal ball and compression spring in the anti-tipping assembly provide elastic support for the root locking mechanism, dynamically adjusting the position of the root locking mechanism within the extension arm sleeve to ensure a smooth and stable working process.

[0053] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A root locking mechanism for a space extension arm, used to lock a support plate (3) and a sleeve (4) of the space extension arm, wherein the support plate (3) is perpendicular to the axial direction of the sleeve (4), characterized in that: The root locking mechanism includes: a locking mechanism unit (1), an anti-tipping mechanism assembly (2), and a structural locking groove (401) on the inner wall of the sleeve (4), wherein: Four anti-tipping mechanism components (2) are installed one-to-one on four locking mechanism units (1), with one end in contact with the inner wall of the sleeve (4) to provide support for the root locking mechanism; The bottom ends of the four locking mechanism units (1) are installed one-to-one with the four corners of the support plate (3); The inner wall of the sleeve (4) is evenly distributed with four structural locking grooves (401), which respectively cooperate with the upper end of the four locking mechanism units (1) to lock; The root locking mechanism unit (1) includes: a frame (101), a lifting handle (102), a locking spring cylinder (103), a spring cover (104), a locking spring (105), a return spring (106), a return spring cover (107), a slide bar (108), a short connecting rod (109), and a long connecting rod (110); wherein: The frame (101) is the housing of the root locking mechanism unit (1), and the bottom is connected to the support plate (3); a protruding structure is provided at one end of the upper part of the frame (101), and a hole is provided on it. The hole is used to connect one end of the short connecting rod (109) to form a rotating joint connection. The other end of the short connecting rod (109) is connected to one end of the long connecting rod (110), and the other end of the long connecting rod (110) is connected to one end of the slide rod (108); the other end of the slide rod (108) passes through the shaft hole in the middle of the frame of the frame (101) to form a sliding joint; the slide rod (108), the long connecting rod (110), the short connecting rod (109) and the frame (101) are combined to form a four-bar linkage mechanism; The outer diameter of the slide rod (108) decreases stepwise from one end of the connecting rod (110) to the other end; the locking spring cylinder (103) is located inside the frame (101) and is sleeved on the larger diameter end of the slide rod (108); the spring cap (104) is rigidly fixed in the middle position of the slide rod (108) and moves with the slide rod during operation; the locking spring (105) is sleeved on the slide rod (108) and is located between the spring cap (104) and the locking spring cylinder (103). Between them, the spring cover (104) and the locking spring cylinder (103) work together to compress the locking spring (105); the return spring cover (107) is located inside the frame (101) and is sleeved on the smaller diameter end of the slide rod (108); the return spring (106) is sleeved on the slide rod (108) and is located between the spring cover (104) and the return spring cover (107); the spring cover (104) and the return spring cover (107) work together to compress the return spring (106). The lifting handle (102) is S-shaped and located on the upper part of the frame (101). One end of it is rigidly connected to the outside of the locking spring cylinder (103), and a secondary roller (112) is provided on it. The other end rests on the upper end of the frame (101), and a main roller (111) is provided on the lower surface of this end. The main roller (111) and the secondary roller (112) constrain the degree of freedom of the lifting handle (102), so that it can only perform linear motion.

2. The root locking mechanism for a spatial extension arm according to claim 1, characterized in that: The anti-rollover mechanism assembly (2) includes: an anti-rollover rod (201), a slider (202), a slider cover (203), a slider rod (204), an anti-rollover spring (205), an anti-rollover spring cover (206), and an anti-rollover spring sleeve (207); wherein: One end of the anti-tipping bar (201) is connected to the middle of the frame (101), and the upper part of the other end is equipped with an anti-tipping spring sleeve (207), while the lower part has a baffle structure integrally formed with the anti-tipping bar (201); the anti-tipping spring cover (206) is located inside the anti-tipping spring sleeve (207), and the anti-tipping spring (205) is located between the anti-tipping spring cover (206) and the baffle structure of the anti-tipping bar (201); the sliding ball The lower end of the rod (204) passes through the through hole on the upper end face of the anti-tipping spring sleeve (207), the corresponding through hole on the anti-tipping spring cover (206), the anti-tipping spring (205), and the corresponding through hole on the baffle structure of the anti-tipping rod (201); the ball cover (203) is located at the upper end of the ball rod (204), and the ball (202) and the ball cover (203) are connected by a ball pair, which can realize free rolling at the end of the ball rod.

3. The root locking mechanism for a spatial extension arm according to claim 2, characterized in that: During operation, the anti-tipping mechanism component (2) has a sliding ball (202) that is always in contact with the inner cylindrical side wall of the sleeve (4) and rolls freely, providing support for the root locking mechanism.

4. The root locking mechanism for a spatial extension arm according to claim 1, characterized in that: The inner wall of the sleeve (4) is provided with a positioning structure that cooperates with the protrusion structure provided at one end of the upper part of the frame (101), and the corresponding structural locking groove (401) is set on a straight line parallel to the axial direction of the sleeve (4).

5. The root locking mechanism for a spatial extension arm according to claim 4, characterized in that: When the structural locking groove (401) engages with the upper end of the locking mechanism unit (1) for locking: An external pulling force F acts on the lifting handle (102), and the root locking mechanism moves in the direction of the pulling force F. When the protruding structure at one end of the upper part of the frame (101) is completely in contact with the positioning structure on the inner wall of the sleeve (4), and the root locking mechanism unit (1) stops moving, the return spring (106) and the locking spring (105) are compressed in sequence, which drives the slide bar (108) to move in the direction of the pulling force, and then drives the entire four-bar linkage to start moving. The short link (109) gradually changes to a horizontal state, and the long link (110) gradually changes to a vertical state. Finally, the upper end of the long link (110) is in complete contact with the structural locking groove (401) to complete the locking.

6. The root locking mechanism for a spatial extension arm according to claim 5, characterized in that: When the external tension is released, the root locking mechanism unlocks automatically, specifically as follows: The return spring (106) and the locking spring (105) are no longer compressed by the external lifting force and gradually return to their original length on their own. Under the action of the elastic force, the slide bar (108) moves in the opposite direction to the locking stage, thereby driving the entire four-bar linkage to begin unlocking, that is, the long link (110) separates from the structural locking groove (401) and completes the unlocking.

7. The root locking mechanism for a spatial extension arm according to claim 4, characterized in that: The distance between the positioning structure on the inner wall of the sleeve (4) and the corresponding structural locking groove (401) is determined based on the dimensions of the four-bar linkage and the compression of the return spring (106) and the locking spring (105).

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