Space stretching device based on cold welding technology

Abstract

The invention discloses a space stretching device based on a cold welding technology and belongs to the field of spaceflight. The problems that an inflatable mechanical arm is adopted in an existing large space unfolding mechanism, and an inflatable structure is low in rigidity, poor in bearing capacity and prone to deformation in the spacecraft operation process are solved. An existing large space unfolding mechanism is large in driving number and complex in structure, and the maintenance cost and the transportation weight are increased. The device comprises a stretching mechanism and a stretching driving mechanism, the stretching mechanism comprises a plurality of coiling connecting rods, and the coiling connecting rods are hinged in sequence, so that the stretching mechanism can be folded and stored; the stretching driving mechanism is connected to the stretching mechanism and can generate side pressure on the coiled connecting rod; when the stretching mechanism is in the folded state, the stretching driving mechanism drives the coiling connecting rods to turn over, and every two adjacent coiling connecting rods are straightened and make contact with each other, so that the end faces of every two adjacent coiling connecting rods are mutually extruded and cold welding occurs. The method is mainly used for executing space tasks.

Description

Technical Field

[0001] The invention belongs to the field of aerospace and relates to a space stretching device based on cold welding technology. Background Art

[0002] Space deployment mechanisms have found widespread application in large space telescopes, large-aperture antennas, and space robotic arms. With the continuous advancement of aerospace technology, space structures are becoming larger and more complex. However, the limited space within spacecraft makes it difficult to accommodate large space structures. Therefore, there is an urgent need to design space deployment mechanisms that can fold, store, and deploy. During launch and transportation, large space structures are folded together, maintaining a relatively small size. Once the spacecraft enters space and reaches its intended orbit, a series of control measures and mechanical design enable the mechanisms to be deployed and locked mid-air, ensuring the smooth execution of the mission.

[0003] my country has made significant progress in research on space deployment mechanisms, which have been successfully applied in numerous space missions. For example, the BeiDou-3 satellite is equipped with an antenna reflector with a deployment diameter of 5 meters. Zhangheng-1, the satellite with the most deployment mechanisms in China to date, has a deployment diameter of 5 meters and a palm-sized stowage. However, existing deployment mechanisms still have the following shortcomings: First, existing large deployment mechanisms have low structural rigidity and poor load-bearing capacity, making them prone to deformation during spacecraft operation. Second, the drive mechanisms of existing large deployment mechanisms are complex and heavy, increasing maintenance costs and shipping weight. Summary of the Invention

[0004] In view of this, the present invention provides a spatial extension device based on cold welding technology, which can utilize an extension drive mechanism to drive the extension mechanism to expand, so that two adjacent coiled connecting rods come into contact and are connected into one based on cold welding technology, and the extension mechanism changes from flexible to rigid.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A spatial stretching device based on cold welding technology includes a stretching mechanism and a stretching drive mechanism. The stretching mechanism includes multiple coiled links, which are hinged in sequence so that the stretching mechanism can be folded and stored; the stretching drive mechanism is connected to the stretching mechanism and can generate lateral pressure on the coiled links; when the stretching mechanism is in a folded state, the stretching drive mechanism drives the coiled links to flip, and two adjacent coiled links are straightened and contacted, so that the end faces between the two adjacent coiled links are squeezed against each other and cold welded.

[0007] Furthermore, the extension drive mechanism includes an expansion airbag and an inflation component. The expansion airbag is arranged along the length direction of the extension mechanism. The inflation component is connected to the expansion airbag and can inflate the expansion airbag.

[0008] Furthermore, the deployed airbag is curved and bends toward one side of the extension mechanism.

[0009] Furthermore, the inflatable component is a gas cylinder or a gas generator.

[0010] Furthermore, the coiled connecting rod is made of titanium or aluminum.

[0011] Furthermore, it also includes a climbing platform and a climbing drive mechanism. The stretching mechanism is provided with two, the climbing platform is slidably connected to the two stretching mechanisms, and the climbing drive mechanism can drive the climbing platform to move along the length direction of the stretching mechanism.

[0012] Furthermore, the climbing drive mechanism includes a guide pulley, a climbing rope, a drive motor and a winding wheel. The drive motor is arranged at the end of the extension mechanism and is drive-connected to the winding wheel. There are two guide pulleys, and the two guide pulleys are respectively installed on the tips of the two extension mechanisms. There are two climbing ropes, and each climbing rope corresponds to a guide pulley. One end of each climbing rope is connected to the climbing platform, and the other end passes around the corresponding guide pulley and is wound onto the winding wheel.

[0013] Furthermore, it also includes a locking mechanism. The stretching mechanism is provided with two. When the two stretching mechanisms are straightened, the locking mechanism connects two laterally adjacent coiled connecting rods in the two stretching mechanisms to keep the relative positions of the two stretching mechanisms unchanged.

[0014] Furthermore, the locking mechanism includes two mortise and tenon blocks that cooperate with each other, and the two mortise and tenon blocks are respectively installed on the opposite surfaces of two laterally adjacent coiled connecting rods in the two extension mechanisms; when the two extension mechanisms are unfolded and straightened, the two mortise and tenon blocks are squeezed against each other and cold welded.

[0015] Furthermore, the opposing surfaces of the two mortise and tenon blocks are respectively provided with concave and convex surfaces that lock with each other.

[0016] The beneficial effects of the present invention compared with the prior art are:

[0017] 1. The present invention utilizes a multi-section coiled rod design to allow the extension mechanism to be coiled into a spiral shape, resulting in a compact overall size and convenient transport in space. When the extension mechanism needs to be deployed, the extension drive mechanism drives the spiral extension mechanism to unfold and straighten. The extension drive mechanism also exerts lateral pressure on the coiled connecting rods. Under this pressure, the principle of metal's propensity for cold welding in space environments is exploited to cause cold welding between adjacent coiled rods. This connects all coiled connecting rods of the extension mechanism into a single entity, forming a mechanical arm with a certain degree of rigidity, ensuring stability during subsequent operations.

[0018] 2. The expansion drive mechanism of the present invention utilizes an airbag. This allows it to be coiled into a spiral along with the expansion mechanism, minimizing space and volume, making it easier to transport. Furthermore, the deployment airbag serves as the power source for resetting all coiled links, providing a single drive mechanism. This simple structure and lightweight design reduce maintenance costs and shipping weight. Furthermore, the deployment airbag of the present invention is designed with a certain curvature, curving toward one side of the expansion mechanism. This creates an inward compressive force on the adjacent coiled links after the deployment airbag is fully inflated. This compressive force allows the contacting end surfaces of the two adjacent coiled links to quickly connect, accelerating the cold welding process between the two adjacent coiled links.

[0019] 3. The present invention also incorporates a locking mechanism between the two extension mechanisms to ensure that their relative positions remain fixed after extension, thereby ensuring the stability of the entire spatial extension device. The locking mechanism utilizes two cooperating mortise and tenon joints made of metals such as titanium or aluminum, which are susceptible to cold welding. The two mortise and tenon joints compress and cold weld against each other, thereby connecting the two laterally adjacent coiled connecting rods. This ensures that the relative positions of the two extension mechanisms remain unchanged after extension and extension, thereby ensuring the stability of the climbing platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are incorporated in and constitute a part of this application and are used to provide a further understanding of the present invention.

[0021] Figure 1 This is a structural schematic diagram of a space stretching device based on cold welding technology of the present invention.

[0022] Figure 2 This is an enlarged view of a space stretching device based on cold welding technology of the present invention.

[0023] Figure 3 for Figure 2 A partial enlarged view of point A in the middle.

[0024] Figure 4 Schematic diagram of the stretching mechanism coiled into a spiral shape.

[0025] Figure 5This is a schematic diagram of the assembly status between two laterally adjacent coiled connecting rods.

[0026] Figure 6 This is a schematic diagram of the state before assembly between two laterally adjacent coiled connecting rods.

[0027] Description of reference numerals:

[0028] Extension mechanism 1, coiled connecting rod 11, slide 111, hinge 12;

[0029] Extending the driving mechanism 2 and deploying the airbag 21;

[0030] Climbing platform 3;

[0031] Climbing drive mechanism 4, guide pulley 41, drive motor 42;

[0032] Locking mechanism 5, mortise and tenon block 51, first locking groove 511, first locking block 512, second locking groove 513, second locking block 514. DETAILED DESCRIPTION

[0033] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Figure 1 FIG. 1 shows a schematic structural diagram of a space stretching device based on cold welding technology in this embodiment. Figure 1 In this embodiment, a space stretching device based on cold welding technology includes a stretching mechanism 1 and a stretching driving mechanism 2. The stretching mechanism 1 includes multiple coiled connecting rods 11 and multiple hinges 12. The multiple coiled connecting rods 11 are arranged in sequence, and two adjacent coiled connecting rods 11 are connected via a hinge 12. The coiled rods are made of metal materials such as titanium or aluminum that are prone to cold welding. Figure 4 , the stretching mechanism 1 can be wound into a spiral shape. Figure 5 The hinge 12 is preferably a hinge, which is arranged at the outer end surfaces of the two adjacent coiled links 11. In this way, when the two adjacent coiled links 11 are in a bent state, the opposite end surfaces therebetween are in a separated state, avoiding premature cold welding between the two; when the two adjacent coiled links 11 are straightened, the end surfaces of the two adjacent coiled links 11 can be completely in contact, increasing the cold welding area.

[0035] Combine Figure 1 and Figure 2The extension drive mechanism 2 is arranged on the outside of the extension mechanism 1 and can drive the spiral extension mechanism 1 to unfold and straighten. Before the space extension device is launched by the rocket, the multiple coiled links 11 are bent in sequence to make the extension mechanism 1 coiled into a spiral shape, reducing the transportation volume and size. After the space extension device is transported to the target position by the rocket, the extension drive mechanism 2 drives the coiled links 11 to flip and reset, and the two adjacent coiled links 11 gradually become collinear from the bent state, and the end faces of the two adjacent coiled links 11 are squeezed against each other by the drive of the extension drive mechanism 2, thereby cold welding occurs, thereby achieving a fixed connection between the two adjacent coiled links 11. At this time, the extension mechanism 1 is transformed from a flexible, bendable link to an irreversible rigid link.

[0036] As can be seen, the multi-section coiled rod design of this embodiment allows the extension mechanism 1 to be coiled into a spiral shape, resulting in a smaller overall size and facilitating space transport. When the extension mechanism 1 needs to be deployed, the extension drive mechanism 2 drives the spiral extension mechanism 1 to unfold and straighten. The extension drive mechanism 2 also exerts lateral pressure on the coiled connecting rod 11. Under this pressure, the principle that metals are prone to cold welding in the space environment (the combined effects of ultra-high vacuum, high-energy radiation, extreme temperatures, microgravity, and the lack of contamination on metal surfaces eliminate the obstacles that prevent natural adhesion / cold welding of metal surfaces in terrestrial environments) is exploited to cause cold welding between adjacent coiled rods. This connects all coiled connecting rods 11 of the extension mechanism 1 into a single unit, forming a connecting rod with a certain degree of rigidity, ensuring stability during subsequent operations. It should be noted that in space, cold welding poses a hazard to spacecraft and may cause active mechanisms (such as antenna deployment mechanisms, solar panel hinges, scanning mechanisms, valves, relay contacts, etc.) to become stuck, stick, or experience abnormally increased friction, resulting in mission failure. Therefore, preventing cold welding is an important consideration in spacecraft design. This embodiment transforms this unfavorable condition into a technical means of fixing multiple coiled connecting rods 11 together, increasing the stiffness of the extension mechanism 1 after deployment and straightening, and overcoming people's prejudice against cold welding technology.

[0037] like Figure 1As shown, the expansion drive mechanism 2 of this embodiment includes a deployment airbag 21 and an inflatable component 22. The deployment airbag 21 is an elongated, closed-end structure with a gas injection port at the other end. The deployment airbag 21 is fixedly connected to each coiled connecting rod 11 along the length of the expansion mechanism 1, specifically by gluing. When the expansion mechanism 1 is coiled into a spiral, the deployment airbag 21 is in an uninflated state and can be spiraled along with the coiled connecting rod 11, without increasing the overall volume of the space expansion device. The inflatable component 22 is disposed at the end of the expansion mechanism 1 and communicates with the gas injection port of the deployment airbag 21. The inflatable component 22 can be a gas cylinder or a gas generator. The gas cylinder compresses high-pressure gas. When the deployment airbag 21 is deployed, the gas cylinder is deflated to inflate the deployment airbag 21. The deployment speed of the deployment airbag 21 can be controlled by adjusting the opening of the gas valve. The overall structure is simple and the solution is mature. The gas generator inflates the airbag using gases generated by a chemical reaction. Because the reaction materials are mostly solid, they occupy a small volume and are lightweight. By using different reaction materials, the deployment rate can be adjusted. When the space deployment device is transported to the target location, the inflatable component 22 inflates the deployment airbag 21, causing the deployment airbag 21 to gradually expand and straighten. Simultaneously, the deployment airbag 21 exerts a squeezing force on the coiled connecting rods 11 connected to it, causing the coiled connecting rods 11 to flip inward until the two adjacent coiled connecting rods 11 are collinear, meaning that the two adjacent coiled connecting rods 11 gradually change from a bent state to a straight state. In other words, as the deployment airbag 21 expands and straightens, the extension mechanism 1 can straighten along with the deployment airbag 21, thereby achieving deployment of the extension mechanism 1. The extension drive mechanism 2 of this embodiment is in the form of an airbag. On the one hand, it can be coiled into a spiral shape together with the extension mechanism 1, which does not take up too much space and volume, making it easy to transport; on the other hand, the unfolded airbag 21 serves as the power source for resetting all the coiled connecting rods 11, has a single drive, a simple structure, and a light weight, which reduces maintenance costs and transportation weight.

[0038] In order to speed up the cold welding speed between the two adjacent coiled links 11, the deployment airbag 21 of this embodiment is bent toward one side of the extension mechanism 1, that is, the deployment airbag 21 is designed to have a certain curvature, so that after the deployment airbag 21 is fully expanded, it can generate an inward extrusion force on the two adjacent coiled links 11, and the end surfaces of the two adjacent coiled links 11 in contact can be quickly connected together under this extrusion pressure.

[0039] like Figure 2 and Figure 3As shown, the present embodiment has two extension mechanisms 1, which are symmetrically arranged. When the two extension mechanisms 1 are in a spiral shape, a state similar to insect antennae is formed between the two, that is, the two extension mechanisms 1 are coiled outward and there is a certain distance between them. When the two extension mechanisms 1 are fully extended, they are in a horizontal side-by-side state. Figure 5 Each winding link 11 has a sliding groove 111 running through both ends in the length direction. When the stretching mechanism 1 is straightened, the sliding grooves 111 on all the winding links 11 are connected to form a through vertical slideway. In this way, two stretching mechanisms 1 arranged side by side form two side-by-side slideways. Figure 2 and Figure 3 The space extension device of this embodiment also includes a climbing platform 3 and a climbing drive mechanism 4. One end of the climbing platform 3 is provided with two side-by-side sliders, which correspond to two slideways respectively, and each slider is slidably connected to the corresponding slideway. Figure 2 The climbing drive mechanism 4 is disposed at the end of the extension mechanism 1 and is drivably connected to the climbing platform 3. The climbing drive mechanism 4 is capable of driving the climbing platform 3 along the length of the extension mechanism 1 to facilitate the transport of task devices (such as sensors). It should be noted that when the two extension mechanisms 1 are in a spiral configuration, the climbing platform 3 is located within the slide groove 111 of the coiled connecting rod 11 at the end of the two extension mechanisms 1. This does not affect the coiling of the two extension mechanisms 1 nor does it become detached from the slides. When the two extension mechanisms 1 are straightened, the climbing drive mechanism 4 can directly drive the climbing platform 3 to slide along the two slides without requiring reassembly of the climbing platform 3 and the slides. It should also be noted that the climbing platform 3 and the sliders on the climbing platform 3 are made of materials that are not susceptible to cold welding, such as polyester fiber or aluminum-based ceramic composite materials. A gap exists between the sliders and the slides, making cold welding less likely even in the absence of pressure.

[0040] like Figure 2As shown, the climbing drive mechanism 4 of this embodiment includes a guide pulley 41, a climbing rope (not shown), a drive motor 42, and a winding reel (not shown). The drive motor 42 is located at the end of the extension mechanism 1 and is drivably connected to the winding reel. Two guide pulleys 41 are provided, one mounted at the tip of each extension mechanism 1. Two climbing ropes are provided, one for each guide pulley 41. One end of each climbing rope is connected to the climbing platform 3, and the other end passes around its respective guide pulley 41 and extends downward along the length of the extension mechanism 1, where it is wound onto the winding reel. When the two extension mechanisms 1 are deployed and straightened, the drive motor 42 drives the winding reel to reel in the climbing ropes, generating an upward pulling force on the climbing platform 3, thereby enabling the climbing platform 3 to move upward. The working device of the climbing platform 3 can be adjusted according to actual conditions. To prevent cold welding between the climbing ropes and the extension mechanism 1, the climbing ropes are made of a material that is not prone to cold welding, such as nylon. In addition, the climbing drive mechanism 4 adopts a rope drive mode because the climbing rope is flexible and can be coiled together with the stretching mechanism 1; and the climbing rope is light in weight and simple in structure, and will not increase the transportation space and weight.

[0041] like Figure 2 and Figure 5 As shown, in order to ensure that the relative position of the two stretching mechanisms 1 does not change after being stretched, that is, the stability of the entire space stretching device. The space stretching device of this embodiment also includes a locking mechanism 5, which is used to lock the two stretching mechanisms 1 after being stretched. Specifically, combined with Figure 5 The locking mechanism 5 includes a plurality of pairs of mortise and tenon blocks 51, each pair of mortise and tenon blocks 51 corresponds to a group of coiled links 11, wherein two laterally adjacent coiled links 11 in the two extension mechanisms 1 form a group. Each pair of mortise and tenon blocks 51 includes two mutually cooperating mortise and tenon blocks 51, and the two mortise and tenon blocks 51 are respectively installed on the opposite surfaces of the two coiled links 11 in each group. The mortise and tenon blocks 51 are made of metal materials such as titanium or aluminum that are prone to cold welding. In this way, during the unfolding and straightening process of the two extension mechanisms 1, the two mortise and tenon blocks 51 gradually approach each other until the two mortise and tenon blocks 51 are squeezed against each other and cold welded, at which point the two mortise and tenon blocks 51 are connected as one. The two laterally adjacent coiled links 11 are connected as one via the two mortise and tenon blocks 51, ensuring that the relative positions of the two extension mechanisms 1 will not change after unfolding and straightening. This ensures the climbing stability of the climbing platform 3.

[0042] In order to speed up the connection of the two mortise and tenon blocks 51 and ensure the stability of the connection. Figure 5The two mortise and tenon blocks 51 have mating concave and convex surfaces on their opposing surfaces. Specifically, the lower surface of the mortise and tenon block 51 on the left coiled link 11 is provided with a first locking groove 511 and a first locking block 512, while the upper surface of the mortise and tenon block 51 on the right coiled link 11 is provided with a second locking groove 513 and a second locking block 514. The first locking block 512 and the second locking block 514 are both triangular protrusions, while the first locking groove 511 and the second locking groove 513 are both triangular grooves. During the unfolding and straightening process of the two extension mechanisms 1, the two laterally adjacent coiled connecting rods 11 flip toward each other, and the oblique guide surface of the first locking block 512 of the left mortise and tenon block 51 abuts the oblique guide surface of the second locking block 514 of the right mortise and tenon block 51 and slides along the guide surface until the first locking block 512 is inserted into the second locking groove 513 of the right mortise and tenon block 51, and the second locking block 514 of the right mortise and tenon block 51 is inserted into the first locking groove 511 of the left mortise and tenon block 51. The two extension mechanisms 1 are mutually locked via the two mortise and tenon blocks 51. In addition, the concave and convex surface design of the mortise and tenon blocks 51 increases the cold welding area, speeding up the cold welding speed and enhancing the locking effect of the two extension mechanisms 1.

[0043] The following combination Figures 1 to 5 The working principle and workflow of a space stretching device based on cold welding technology of the present invention are described in detail.

[0044] Before the space extension device is launched by a rocket, multiple coiled links 11 are bent sequentially to form the extension mechanism 1 into a spiral. After the space extension device is transported by the rocket to the target location, the inflatable component 22 inflates the deployment airbag 21, which gradually expands and straightens. The deployment airbag 21 exerts a squeezing force on the coiled links 11 connected to it, causing the coiled links 11 to flip inward until two adjacent coiled links 11 are collinear. The end faces of the two adjacent coiled links 11 are squeezed together by the squeezing force of the deployment airbag 21, forming a cold weld, thus achieving a fixed connection between the two longitudinally adjacent coiled links 11. At the same time, as the two extension mechanisms 1 unfold and straighten, the two laterally adjacent coiled connecting rods 11 flip toward each other, and the oblique guide surface of the first locking block 512 of the left mortise and tenon block 51 abuts against the oblique guide surface of the second locking block 514 of the right mortise and tenon block 51, sliding along the guide surface until the first locking block 512 is inserted into the second locking groove 513 of the right mortise and tenon block 51, and the second locking block 514 of the right mortise and tenon block 51 is inserted into the first locking groove 511 of the left mortise and tenon block 51. The two extension mechanisms 1 are mutually locked via the two mortise and tenon blocks 51. At this time, the extension mechanism 1 changes from a flexible, bendable connecting rod to an irreversible rigid connecting rod. The drive motor 42 drives the winding wheel to collect the rope, and the climbing rope generates an upward driving force on the climbing platform 3. The upward movement of the climbing platform 3 realizes the transportation of the task device.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A space stretching device based on cold welding technology, characterized in that: include: An extension mechanism includes a plurality of coiled connecting rods, the plurality of coiled connecting rods being hingedly connected in sequence so that the extension mechanism can be folded and stored; an extension drive mechanism connected to the extension mechanism and capable of generating lateral pressure on the coiled connecting rod; When the extension mechanism is in the folded state, the extension drive mechanism drives the coiled connecting rod to flip, and two adjacent coiled connecting rods are straightened and contacted, so that the end surfaces between the two adjacent coiled connecting rods are pressed against each other and cold welded.

2. A space stretching device based on cold welding technology according to claim 1, characterized in that: The stretching drive mechanism includes a deployment airbag and an inflation component. The deployment airbag is arranged along the length direction of the stretching mechanism. The inflation component is connected to the deployment airbag and can inflate the deployment airbag.

3. The space stretching device based on cold welding technology according to claim 2, characterized in that: The deployed airbag is curved and bends toward one side of the extension mechanism.

4. The space stretching device based on cold welding technology according to claim 3, characterized in that: The inflatable component is a gas cylinder or a gas generator.

5. The space stretching device based on cold welding technology according to claim 1, characterized in that: The material of the coiled connecting rod is titanium or aluminum.

6. The space stretching device based on cold welding technology according to claim 1, characterized in that: It also includes a climbing platform and a climbing drive mechanism. The stretching mechanism is provided with two, the climbing platform is slidably connected to the two stretching mechanisms, and the climbing drive mechanism can drive the climbing platform to move along the length direction of the stretching mechanism.

7. The space stretching device based on cold welding technology according to claim 6, characterized in that: The climbing drive mechanism includes a guide pulley, a climbing rope, a drive motor and a winding wheel. The drive motor is arranged at the end of the extension mechanism and is drive-connected to the winding wheel. There are two guide pulleys, which are respectively installed on the tips of the two extension mechanisms. There are two climbing ropes, each climbing rope corresponds to a guide pulley. One end of each climbing rope is connected to the climbing platform, and the other end passes around the corresponding guide pulley and is wound onto the winding wheel.

8. The space stretching device based on cold welding technology according to claim 1, characterized in that: It also includes a locking mechanism. There are two stretching mechanisms. When the two stretching mechanisms are straightened, the locking mechanism connects two laterally adjacent coiled connecting rods in the two stretching mechanisms to keep the relative positions of the two stretching mechanisms unchanged.

9. The space stretching device based on cold welding technology according to claim 8, characterized in that: The locking mechanism includes two mutually cooperating mortise and tenon blocks, which are respectively installed on the opposite surfaces of two laterally adjacent coiled connecting rods in the two extension mechanisms; when the two extension mechanisms are unfolded and straightened, the two mortise and tenon blocks are squeezed against each other and cold welded.

10. The space stretching device based on cold welding technology according to claim 9, characterized in that: The opposite surfaces of the two mortise and tenon blocks are respectively provided with concave and convex surfaces that lock with each other.

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