Self-loading and unloading type double-layer safety protective fence for building construction

Abstract

The present application relates to the technical field of double-layer safety guardrails, in particular to a self-loading and unloading type building construction double-layer safety guardrail, which comprises a frame, a transport table and a lifting mechanism; the frame is provided with a first platform and a second platform, and the first platform and the second platform are both provided with an extension guide rail; the frame is provided with a work area, a loading and unloading area and a lifting area, and the extension guide rail is arranged in the loading and unloading area; the transport table is arranged in the lifting area of the frame in a liftable manner, and the transport table is provided with an electric guide rail, and the electric guide rail is movably provided with a support table; the lifting mechanism is used for driving the transport table to lift in the lifting area. The present application realizes the function of partition transfer of materials. The operator performs the transfer and storage work of materials in the work area, when the support table moves to the loading and unloading area, the operator transfers the materials to the support table, and then transfers the materials to the designated position through the electric guide rail and the lifting mechanism, thereby realizing the function of partition storage and designated transfer of materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of double-layer safety guardrails, in particular to a self-loading and unloading type double-layer safety guardrail for building construction. BACKGROUND

[0002] In high-altitude operations, in order to protect the safety of construction personnel, a liftable safety guardrail is usually used for personnel and material transportation. However, during high-altitude operations, back-and-forth material handling still has great hidden dangers, which not only increases the working intensity of construction personnel, but also reduces material transportation efficiency and working efficiency.

[0003] Therefore, a self-loading and unloading type double-layer safety guardrail for building construction and a using method thereof are disclosed in a Chinese patent with the authorization announcement number CN118289474B. The storage and conveying assembly is used to limit the material stably, and the control panel is used to start the push-down assembly and the limit-up assembly to stably move the storage and conveying assembly with the material to load and unload, thereby solving the problems of the existing safety guardrail, such as self-loading and unloading, low construction material transportation efficiency, high working intensity of construction personnel, and low safety guardrail use convenience and safety, and achieving the effect of self-loading and unloading.

[0004] However, the conventional equipment needs to use the storage and conveying assembly to convey the material when loading and unloading, and the storage and conveying assembly occupies a large amount of space. When the construction personnel needs to load and unload and classify the material on the safety guardrail, the storage and conveying assembly not only reduces the storage space, but also affects the normal activities of the construction personnel. SUMMARY

[0005] In view of the above problems, a self-loading and unloading type double-layer safety guardrail for building construction is provided, which solves the problem that the material moving facility of the conventional guardrail cannot work with the operator by using the frame, the transportation table, and the lifting mechanism.

[0006] To solve the problems in the prior art, the present application provides a self-loading and unloading type double-layer safety guardrail for building construction, which comprises a frame, a transportation table, and a lifting mechanism. The frame is provided with a first platform and a second platform distributed in a vertical direction from bottom to top. The first platform and the second platform are both provided with an extension guide rail. The frame is provided with a working area, a loading and unloading area, and a lifting area. The extension guide rail is arranged in the loading and unloading area. The transportation table is arranged in the lifting area of the frame in a liftable manner. The transportation table is provided with an electric guide rail. The electric guide rail is movably provided with a support table. The lifting mechanism is used to drive the transportation table to lift in the lifting area. In the working state, when the electric guide rail is connected with the extension guide rail, the electric guide rail controls the support table to move towards the loading and unloading area.

[0007] Preferably, the lifting mechanism comprises a screw rod, an extension shaft, a limiting component and a rotary driving component; the screw rod is rotationally arranged on the frame, and the screw rod is threadedly connected with the transport table; the extension shaft is rotationally arranged on the frame, and the extension shaft is coaxially connected with the screw rod; the rotary driving component is used for driving the extension shaft to rotate; in the working state, when the electric guide rail control support table moves to the extension guide rail, the limiting component limits the extension shaft from rotating.

[0008] Preferably, the limiting component comprises a connecting ring and a limiting ring; the connecting ring is sleeved on the extension shaft; the limiting ring is arranged on the extension shaft in a lifting manner, and the axis of the limiting ring is collinear with the axis of the extension shaft; the frame is provided with a control component used for controlling the limiting ring to lift; when the limiting ring abuts against the connecting ring, the limiting ring limits the connecting ring from rotating around the axis.

[0009] Preferably, the limiting ring is provided with a butt joint column and a first elastic piece, the butt joint column is slidingly installed on the limiting ring, and the two ends of the first elastic piece are connected with the butt joint column and the limiting ring respectively; the connecting ring is provided with the first elastic piece matched with the butt joint column.

[0010] Preferably, the control mechanism comprises a connecting frame, a first transmission component and a second transmission component; the connecting frame is movably arranged on the frame; the connecting frame is transmissionally connected with the support table through the first transmission component; the connecting frame is transmissionally connected with the limiting ring through the second transmission component; in the working state, when the support table moves towards the extension guide rail, the first transmission component is driven through the extrusion of the support table, the first transmission component drives the second transmission component through the transmission of the connecting frame, and the second transmission component controls the limiting ring to move towards the connecting ring.

[0011] Preferably, the first transmission component comprises a counterweight rod and a connecting block; the counterweight rod is arranged on the frame in a lifting manner, and two counterweight rods are arranged in each loading and unloading area; the connecting block is connected with the connecting frame; the top end of the counterweight rod is provided with a first inclined surface, the connecting block is provided with a second inclined surface, and the first inclined surface and the second inclined surface are slidingly matched; when the support table moves towards the loading and unloading area, the counterweight rod of the loading and unloading area is extruded, so that the counterweight rod is in an upward moving state.

[0012] Preferably, the bottom end of the counterweight rod is rotationally provided with a roller.

[0013] Preferably, the frame is provided with a support frame, the support frame is slidingly installed with a bracket, and the limiting ring is connected with the bracket; the bracket is provided with a second elastic piece, and the two ends of the second elastic piece are connected with the bracket and the support frame.

[0014] Preferably, the second transmission component comprises a connecting rod, the connecting rod is connected with the connecting frame; the connecting rod is provided with an oblique protrusion, and the oblique protrusion is slidingly matched with the bracket.

[0015] Preferably, the frame is provided with a protection frame used for protecting the screw rod.

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

[0017] 1. The frame, transport platform and lifting mechanism realize the function of transferring materials in different areas. In the working state, the operator transfers and stores materials in the working area, when the support table moves to the loading and unloading area, the operator transfers the materials to the support table, and then transfers the materials to the designated position through the electric guide rail and lifting mechanism, thereby realizing the function of storing and transferring materials in different areas.

[0018] 2. The screw, extension shaft, limiting assembly and rotary drive assembly realize the function of stabilizing the state of the transport platform during loading and unloading, avoiding the situation that the lifting mechanism controls the lifting of the transport platform when the support table moves to the extension guide rail, thereby improving the stability of the loading and unloading work of the protective fence. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a three-dimensional schematic view of a self-loading and unloading type building construction double-layer safety fence according to the present application.

[0020] Figure 2 is a three-dimensional exploded schematic view of a self-loading and unloading type building construction double-layer safety fence according to the present application.

[0021] Figure 3 is a three-dimensional schematic view of a self-loading and unloading type building construction double-layer safety fence according to the present application.

[0022] Figure 4 is a three-dimensional schematic view of a self-loading and unloading type building construction double-layer safety fence according to the present application.

[0023] Figure 5 is a three-dimensional schematic view of a self-loading and unloading type building construction double-layer safety fence according to the present application.

[0024] Figure 6 is a three-dimensional schematic view of a self-loading and unloading type building construction double-layer safety fence according to the present application.

[0025] Figure 7 is a three-dimensional exploded schematic view of a self-loading and unloading type building construction double-layer safety fence according to the present application.

[0026] Figure 8 is a three-dimensional schematic view of a self-loading and unloading type building construction double-layer safety fence according to the present application.

[0027] Figure 9 is a three-dimensional schematic view of a self-loading and unloading type building construction double-layer safety fence according to the present application. Figure 8 is a three-dimensional schematic view of a self-loading and unloading type building construction double-layer safety fence according to the present application.

[0028] Figure 10 Figure is a self-loading and unloading type of building construction double-layer safety fence second transmission assembly of the application is a three-dimensional schematic view.

[0029] The figure mark is: 1, frame; 11, first platform; 12, second platform; 13, extension rail; 14, guard plate; 141, outer guard plate; 142, inner guard plate; 15, support; 151, bracket; 152, second elastic member; 16, guard frame; 2, transport table; 21, electric guide rail; 22, support table; 3, lifting mechanism; 31, screw; 32, extension shaft; 33, limiting assembly; 331, connecting ring; 3311, butt joint groove; 332, limiting ring; 3321, butt joint column; 3322, first elastic member; 34, rotary drive assembly; 341, rotary driver; 342, worm; 343, worm gear; 4, control mechanism; 41, connecting frame; 42, first transmission assembly; 421, counterweight rod; 4211, roller; 422, connecting block; 43, second transmission assembly; 431, connecting rod; 4311, oblique protrusion. DETAILED DESCRIPTION

[0030] In order to further understand the features, technical means and specific purposes and functions achieved by the application, the application will be described in further detail below with reference to the drawings and specific embodiments.

[0031] Reference Figures 1-3 A self-loading and unloading type of building construction double-layer safety fence, comprising a frame 1, a transport table 2 and a lifting mechanism 3; the frame 1 is provided with a first platform 11 and a second platform 12 distributed in the vertical direction from bottom to top, the first platform 11 and the second platform 12 are both provided with an extension rail 13, the frame 1 is provided with a working area, a loading and unloading area and a lifting area, and the extension rail 13 is arranged in the loading and unloading area; the transport table 2 is arranged in the lifting area of the frame 1 in a lifting manner, the transport table 2 is provided with an electric guide rail 21, and the electric guide rail 21 is movably provided with a support table 22; the lifting mechanism 3 is used to drive the transport table 2 to lift in the lifting area; in the working state, when the electric guide rail 21 is connected with the extension rail 13, the electric guide rail 21 controls the support table 22 to move towards the loading and unloading area.

[0032] The application realizes the function of partition transfer of materials through the frame 1, the transport table 2 and the lifting mechanism 3. In the working state, the operator carries out the transfer and storage work of materials in the working area, when the support table 22 moves to the loading and unloading area, the operator transfers the materials to the support table 22, and then transfers the materials to the designated position through the electric guide rail 21 and the lifting mechanism 3, thereby realizing the function of partition storage and designated transfer of materials. The problem that the material transfer facility of the traditional protective fence cannot work with the operator is solved. The frame 1 is provided with a controller for human-computer interaction, and the lifting mechanism 3 is electrically connected with the controller. In order to improve the storage capacity of the frame 1, two working areas and two loading and unloading areas are arranged on the first platform 11 and the second platform 12, and the lifting area is arranged between the two loading and unloading areas, and the working area is arranged on the side away from the lifting area of the loading and unloading area, so that the support table 22 can be moved to any one of the loading and unloading areas through the transport table 2 in the lifting area. The electric guide rail 21 is preferably a ball screw type electric guide rail 21, the ball screw and the nut are in rolling friction through the ball, the friction is small, and the support table 22 can be controlled with high precision. The frame 1 is provided with double protective plates 14, the protective plates 14 are outer protective plates 141 and inner protective plates 142 respectively, the outer protective plates 141 are preferably metal fences, and the inner protective plates 142 are preferably tempered glass, and the protective effect is achieved through the cooperation of the outer protective plates 141 and the inner protective plates 142.

[0033] When storing materials, the operator can classify and store materials in the working area. When the support table 22 moves to the loading and unloading area, the operator in the working area adjacent to the loading and unloading area can transfer the materials between the working area and the loading and unloading area. When transferring materials by using the transport table 2, the operator first transfers the materials to the support table 22 in the loading and unloading area, and then controls the support table 22 to reset through the electric guide rail 21. When the support table 22 completely moves to the lifting area, the transport table 2 is lifted in the lifting area through the lifting mechanism 3, and the transfer work of the materials is carried out.

[0034] Reference Figure 3 and Figure 4 : The lifting mechanism 3 comprises a screw rod 31, an extension shaft 32, a limiting assembly 33 and a rotary driving assembly 34; the screw rod 31 is rotationally arranged on the frame 1, and the screw rod 31 is threadedly connected with the transport table 2; the extension shaft 32 is rotationally arranged on the frame 1, and the extension shaft 32 is coaxially connected with the screw rod 31; the rotary driving assembly 34 is used for driving the extension shaft 32 to rotate; in the working state, when the electric guide rail 21 controls the support table 22 to move to the extension guide rail 13, the limiting assembly 33 limits the rotation of the extension shaft 32.

[0035] The application realizes the function of stabilizing the state of the transport platform 2 during loading and unloading by the screw rod 31, the extension shaft 32, the limiting assembly 33 and the rotary driving assembly 34, avoids the situation that the support platform 22 is derailed when the lifting mechanism 3 controls the lifting of the transport platform 2 when the support platform 22 moves to the extension guide rail 13, and further improves the stability of the loading and unloading work of the guardrail. The rotary driving assembly 34 comprises a rotary driver 341, a worm 342 and a worm wheel 343, the rotary driver 341 is arranged at the top end of the frame 1, the worm 342 is rotationally arranged on the frame 1, the worm wheel 343 is sleeved on the extension shaft 32, and the worm 342 is in meshing connection with the worm wheel 343. The rotary driver 341 is preferably a servo motor, and the rotary driver 341 is electrically connected with the controller. When the material is transferred, the operator first sends a signal to the rotary driver 341 through the controller, the rotary driver 341 drives the extension shaft 32 and the screw rod 31 to rotate after receiving the signal, and the screw rod 31 drives the transport platform 2 in threaded connection to lift in the lifting area. After the transport platform 2 moves to the first platform 11 or the second platform 12, when the electric guide rail 21 is in communication with the extension guide rail 13, the electric guide rail 21 controls the support platform 22 to slide towards the extension guide rail 13, and the support platform 22 is completely moved to the loading and unloading area. The operator transfers the material, and after the support platform 22 moves away from the lifting area, the limiting assembly 33 limits the rotation of the extension shaft 32, so that the operator is prevented from causing the lifting mechanism 3 to control the lifting of the transport platform 2 due to misoperation during the loading and unloading process.

[0036] With reference to Figure 4 And Figure 6 The limiting assembly 33 comprises a connecting ring 331 and a limiting ring 332, the connecting ring 331 is sleeved on the extension shaft 32, the limiting ring 332 is arranged on the extension shaft 32 in a lifting manner, the axis line of the limiting ring 332 is collinear with the axis line of the extension shaft 32, and the frame 1 is provided with a control assembly for controlling the lifting of the limiting ring 332, and when the limiting ring 332 abuts against the connecting ring 331, the limiting ring 332 limits the rotation of the connecting ring 331 around the axis line.

[0037] As the first embodiment of the limiting assembly 33, the application realizes the function of limiting the rotation of the extension shaft 32 by the connecting ring 331, the limiting ring 332 and the control mechanism 4. The limiting ring 332 is in sliding fit with the extension shaft 32. When the connecting ring 331 abuts against the limiting ring 332, in order to improve the friction between the limiting ring 332 and the connecting ring 331, anti-skid lines are arranged on the contact surface of the connecting ring 331 and the limiting ring 332, which are not shown in the figure. When the limiting ring 332 is separated from the extension shaft 32, the rotary driving assembly 34 can drive the extension shaft 32 to rotate, and the limiting ring 332 is in a static state. When the limiting ring 332 abuts against the connecting ring 331, the rotation of the extension shaft 32 and the connecting ring 331 is hindered by the static friction between the limiting ring 332 and the connecting ring 331.

[0038] With reference toFigure 4 、 Figure 6 and Figure 7 : The limiting ring 332 is provided with a docking column 3321 and a first elastic member 3322, the docking column 3321 is slidingly installed on the limiting ring 332, and the two ends of the first elastic member 3322 are respectively connected with the docking column 3321 and the limiting ring 332; the connecting ring 331 is provided with the first elastic member 3322 matched with the docking column 3321.

[0039] As the second embodiment of the limiting assembly 33, the present application realizes the function of limiting the rotation of the extension shaft 32 when the connecting ring 331 and the limiting ring 332 abut by means of the docking column 3321, the first elastic member 3322 and the docking groove 3311. When the control mechanism 4 controls the connecting ring 331 to abut against the limiting ring 332, if the docking column 3321 is misaligned with the docking groove 3311, the docking column 3321 is subjected to the pressure of the connecting ring 331, and the first elastic member 3322 is contracted under the action of the pressure, and the docking column 3321 is also relatively contracted. After the rotary driving assembly 34 drives the extension shaft 32 to rotate, the extension shaft 32 drives the connecting ring 331 to rotate, and when the docking groove 3311 is aligned with the docking column 3321, the docking column 3321 is inserted and matched with the docking groove 3311 under the elastic force of the first elastic member 3322, and then the connecting ring 331 is limited to rotate through the limiting ring 332 which is limited to rotate. In order to improve the response speed of the limiting assembly 33, a plurality of docking grooves 3311 are arranged on the connecting ring 331, thereby improving the efficiency of aligning the docking column 3321 with the docking groove 3311.

[0040] Referring to Figure 3 and Figure 5 : The control mechanism 4 comprises a connecting frame 41, a first transmission assembly 42 and a second transmission assembly 43; the connecting frame 41 is movably arranged on the frame 1; the connecting frame 41 is in transmission connection with the support table 22 through the first transmission assembly 42; the connecting frame 41 is in transmission connection with the limiting ring 332 through the second transmission assembly 43; in the working state, when the support table 22 moves towards the extension guide rail 13, the first transmission assembly 42 is driven by the extrusion of the support table 22, and the second transmission assembly 43 is driven by the transmission of the connecting frame 41, and the second transmission assembly 43 controls the limiting ring 332 to move towards the connecting ring 331.

[0041] The application realizes the function of controlling the movement of the limiting ring 332 when the support table 22 moves horizontally through the connecting frame 41, the first transmission assembly 42 and the second transmission assembly 43. When the electric guide rail 21 controls the support table 22 to move towards the extension guide rail 13, the support table 22 drives the first transmission assembly 42 through extrusion, the first transmission assembly 42 transmits the pressure to the second transmission assembly 43 through the connecting frame 41, the second transmission assembly 43 controls the limiting ring 332 to move towards the connecting ring 331, so that the connecting ring 331 abuts against the limiting ring 332, and the limiting assembly 33 limits the rotation of the extension shaft 32.

[0042] With reference to Figure 3 And Figure 8 The first transmission assembly 42 comprises the counterweight rod 421 and the connecting block 422; the counterweight rod 421 is arranged on the frame 1 in a lifting manner, and two counterweight rods 421 are arranged in each loading and unloading area; the connecting block 422 is connected with the connecting frame 41; the top end of the counterweight rod 421 is provided with a first inclined surface, and the connecting block 422 is provided with a second inclined surface, and the first inclined surface and the second inclined surface are in sliding fit; when the support table 22 moves towards the loading and unloading area, the counterweight rod 421 of the loading and unloading area is extruded, so that the counterweight rod 421 is in an upward movement state.

[0043] The application realizes the function of controlling the movement of the connecting frame 41 through the movement of the support table 22 through the counterweight rod 421 and the connecting block 422. In the working state, when the electric guide rail 21 controls the support table 22 to move towards the extension guide rail 13, the support table 22 extrudes the bottom end of the counterweight rod 421, and then pushes the counterweight rod 421 to move upwards, when the counterweight rod 421 moves upwards, the second inclined surface of the connecting block 422 is extruded, and then the connecting frame 41 is pushed to move, and the connecting frame 41 drives the limiting ring 332 to move towards the connecting ring 331 through the second transmission assembly 43. In order to stably drive the counterweight rod 421 to move upwards when the support table 22 abuts against the counterweight rod 421, the two sides of the support table 22 close to the loading and unloading area are provided with third inclined surfaces.

[0044] With reference to Figure 8 The bottom end of the counterweight rod 421 is rotatably provided with a roller 4211.

[0045] The application reduces the abrasion between the support table 22 and the counterweight rod 421 by arranging the roller 4211 at the bottom end of the counterweight rod 421, and improves the extrusion stability of the support wheel to the counterweight rod 421. After the support table 22 lifts the counterweight rod 421, it will continue to slide along the extension guide rail 13, so that the support table 22 and the counterweight rod 421 will have a long time of continuous friction. Therefore, the roller 4211 is arranged at the bottom of the counterweight rod 421, and the rolling friction between the roller 4211 and the support table 22 is used to replace the sliding friction, so as to reduce the abrasion of the support table 22 and the counterweight rod 421, and improve the service life of the parts.

[0046] With reference to Figure 6The frame 1 is provided with a support 15, the support 15 is slidably provided with a bracket 151, and the limiting ring 332 is connected with the bracket 151; the bracket 151 is provided with a second elastic element 152, and two ends of the second elastic element 152 are connected with the support 15 and the bracket 151.

[0047] The support 15, the bracket 151 and the second elastic element 152 are used to support the limiting ring 332, and the elastic force of the second elastic element 152 is used to reset the limiting ring 332. In the working state, when the connecting frame 41 moves under the driving of the first transmission assembly 42, the connecting frame 41 drives the limiting ring 332 to move towards the connecting ring 331 through the second transmission assembly 43, and the second elastic element 152 is elongated under the pressure. After the electric guide rail 21 controls the support table 22 to reset, the counterweight rod 421 is reset under the action of gravity, and the bracket 151 and the limiting ring 332 are reset under the action of the elastic force of the second elastic element 152.

[0048] With reference to Figures 8-10 The second transmission assembly 43 comprises a connecting rod 431, and the connecting rod 431 is connected with the connecting frame 41; the connecting rod 431 is provided with an inclined protrusion 4311, and the inclined protrusion 4311 is slidably connected with the bracket 151.

[0049] The connecting rod 431 and the inclined protrusion 4311 are used to push the limiting ring 332 to move through the movement of the connecting frame 41. The connecting rods 431 on the connecting frames 41 on the two sides of the frame 1 are distributed in a staggered manner. When the connecting rod on one side moves away from the bracket 151, the inclined protrusion 4311 on the connecting rod 431 extrudes the bracket 151, and then pushes the bracket 151 to move upwards, so that the limiting ring 332 on the bracket 151 abuts against the connecting ring 331.

[0050] With reference to Figure 4 And Figure 5 The frame 1 is provided with a protection frame 16 for protecting the screw rod 31.

[0051] The protection frame 16 is used to protect the screw rod 31, so that the screw rod 31 is prevented from being abraded by contacting other objects, and the service life of the screw rod 31 is prolonged. The frame 1 is provided with a guide rod for guiding the movement of the transportation table 2, the guide rod is slidably connected with the transportation table 2, the protection frame 16 comprises a plurality of protection frames 16, and the plurality of protection frames 16 are arranged at intervals. The guide rod and the screw rod 31 are protected by the plurality of protection frames 16. In addition, the protection frame 16 is vertically arranged, the first platform 11 and the second platform 12 are connected through the protection frame 16, and the overall strength of the frame 1 can be further improved.

[0052] The above embodiments only express one or several embodiments of the present application, the description is more specific and detailed, but it cannot be understood as the limitation of the scope of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A self-loading and unloading type double-layer safety construction fence, characterized in that, Frame (1), transport platform (2) and lifting mechanism (3) are included. The first platform (11) and the second platform (12) are arranged on the frame (1) in the vertical direction from bottom to top, and the first platform (11) and the second platform (12) are provided with an extension guide rail (13), and the frame (1) is provided with a working area, a loading and unloading area and a lifting area, and the extension guide rail (13) is arranged in the loading and unloading area. The transport platform (2) is arranged in the lifting area of the frame (1) and can be lifted, and the transport platform (2) is provided with an electric guide rail (21), and the electric guide rail (21) is movably provided with a support platform (22). The lifting mechanism (3) is used for driving the transport platform (2) to lift in the lifting area. In the working state, when the electric guide rail (21) is connected with the extension guide rail (13), the electric guide rail (21) controls the support platform (22) to move towards the loading and unloading area. The lifting mechanism (3) includes a screw rod (31), an extension shaft (32), a limiting assembly (33) and a rotary driving assembly (34). The screw rod (31) is rotatably arranged on the frame (1), and the screw rod (31) is threadedly connected with the transport platform (2). The extension shaft (32) is rotatably arranged on the frame (1), and the extension shaft (32) is coaxially connected with the screw rod (31). The rotary driving assembly (34) is used for driving the extension shaft (32) to rotate. In the working state, when the electric guide rail (21) controls the support platform (22) to move to the extension guide rail (13), the limiting assembly (33) limits the rotation of the extension shaft (32). The limiting assembly (33) includes a connecting ring (331) and a limiting ring (332). The connecting ring (331) is sleeved on the extension shaft (32). The limiting ring (332) is arranged on the extension shaft (32) and can be lifted, and the axis of the limiting ring (332) is collinear with the axis of the extension shaft (32). The frame (1) is provided with a control assembly for controlling the lifting of the limiting ring (332), and when the limiting ring (332) abuts against the connecting ring (331), the limiting ring (332) limits the rotation of the connecting ring (331) around the axis. The limiting ring (332) is provided with a butt joint column (3321) and a first elastic element (3322), the butt joint column (3321) is slidably mounted on the limiting ring (332), and the two ends of the first elastic element (3322) are connected with the butt joint column (3321) and the limiting ring (332) respectively. The connecting ring (331) is provided with a first elastic element (3322) matched with the butt joint column (3321).

2. The self-loading and unloading type construction double safety protective fence according to claim 1, characterized in that, The control mechanism (4) includes a connecting frame (41), a first transmission assembly (42) and a second transmission assembly (43). The connecting frame (41) is movably arranged on the frame (1). The connecting frame (41) is in transmission connection with the support platform (22) through the first transmission assembly (42). The connecting frame (41) is in transmission connection with the limiting ring (332) through the second transmission assembly (43). In the working state, when the support table (22) moves towards the extension guide rail (13), the first transmission assembly (42) is driven by the extrusion of the support table (22), and the first transmission assembly (42) drives the second transmission assembly (43) through the transmission of the connecting frame (41), and the second transmission assembly (43) controls the limiting ring (332) to move towards the connecting ring (331).

3. The self-loading and unloading type construction double safety protective fence according to claim 2, characterized in that, The first transmission assembly (42) comprises a counterweight rod (421) and a connecting block (422). The counterweight rod (421) is arranged on the frame (1) in a lifting manner, and two counterweight rods (421) are arranged in each loading and unloading area. The connecting block (422) is connected with the connecting frame (41). The top end of the counterweight rod (421) is provided with a first inclined surface, and the connecting block (422) is provided with a second inclined surface, and the first inclined surface and the second inclined surface are in sliding fit. When the support table (22) moves towards the loading and unloading area, the counterweight rod (421) of the loading and unloading area is extruded, so that the counterweight rod (421) is in the upward moving state.

4. The self-loading and unloading type construction double-layer safety protective fence according to claim 3, characterized in that, The bottom end of the counterweight rod (421) is rotatably provided with a roller (4211).

5. The self-loading and unloading type construction double-layer safety protective fence according to claim 4, characterized in that, The frame (1) is provided with a support (15), the support is slidably provided with a bracket (151), and the limiting ring (332) is connected with the bracket (151). The bracket (151) is provided with a second elastic element (152), and the two ends of the second elastic element (152) are connected with the support (15) and the bracket (151).

6. The self-loading and unloading type construction double-layer safety protective fence according to claim 5, characterized in that, The second transmission assembly (43) comprises a connecting rod (431), and the connecting rod (431) is connected with the connecting frame (41). The connecting rod (431) is provided with an inclined protrusion (4311), and the inclined protrusion (4311) is in sliding fit with the bracket (151).

7. The self-loading and unloading type construction double-layer safety protective fence according to claim 6, characterized in that, The frame (1) is provided with a protection frame (16) for protecting the screw rod (31).

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