A protective fence for construction work

Abstract

This invention relates to the field of building construction, and particularly to a protective fence for building construction, comprising: two sets of support frames, and a telescopic fence installed between the two sets of support frames. The lower ends of both sets of support frames are fixedly connected to bases, and both sets of support frames are fitted with connecting mechanisms that limit the movement of the telescopic fence. Through the cooperation between the support frames, connecting mechanisms, and telescopic fence, the support frames conveniently support both ends of the telescopic fence, and the spacing between adjacent support frames can be easily adjusted according to the protection range. Simultaneously, the angle between the telescopic fence and the support frames can be adjusted according to the protection requirements of the construction site, thus facilitating the adjustment of the protection range based on the terrain of the construction site. Furthermore, the connecting mechanism further ensures the stability of the telescopic fence installation, improves the flexibility of construction site protection, and is convenient to use in construction sites with corners, thus improving ease of use.

Description

Technical Field

[0001] This invention belongs to the field of building construction technology, and specifically relates to a protective fence for building construction. Background Technology

[0002] Building construction refers to the production activities during the implementation phase of a project. It is the process of building various types of buildings. Specifically, it is the process of turning the lines on the design drawings into physical objects at designated locations. At the same time, it is also necessary to pay attention to construction safety and environmental protection issues, ensure safety and quality during the construction process, and minimize the impact of building construction on the environment.

[0003] During construction, it is usually necessary to enclose the construction area with protective fences. Construction protective fences, also known as site fencing, are used when earthwork excavation, equipment hoisting, or other construction operations are carried out. A protective fence needs to be set up around the work area to prevent unauthorized personnel from entering the work area and causing safety accidents.

[0004] However, common construction site safety fences are usually installed on the ground using anchor bolts, and then adjacent fences are connected and secured with bolts. But in actual use, multiple fences need to be arranged into various shapes according to the terrain of the construction site, and it is inconvenient to connect them at corners. In addition, the angle flexibility of bolt connections is low, which reduces the flexibility of corner connections. Therefore, we need to propose a construction site safety fence. Summary of the Invention

[0005] To address the above problems, the present invention provides a protective fence for construction sites, comprising: Two sets of support frames and a telescopic fence installed between the two sets of support frames. The lower ends of the two sets of support frames are fixedly connected to bases. The telescopic fence is connected to a limiting mechanism on the two sets of support frames. The telescopic fence can be rotated around the support frames as the axis. By installing the telescopic fence on the support frames, the telescopic fence can be adjusted to a certain angle.

[0006] Furthermore, the support frame includes a column, both sides of which are open. Reinforcing beams are welded to both sides of the inner cavity of the column. Two sets of support seats for supporting the telescopic fence are fixedly connected to the bottom of the inner cavity of the column, and pins for rotating the telescopic fence are welded to the support seats.

[0007] Furthermore, the connecting mechanism includes a vertical rod extending through the upper end of the column, a limiting plate fixedly connected to the lower end of the vertical rod, a pin fixedly connected to the lower surface of the limiting plate for insertion into the telescopic fence, and a spring sleeved on the outer side of the vertical rod on the upper surface of the limiting plate.

[0008] Furthermore, two sets of sliding rods are fixedly connected to the outer side of the limiting plate, and sliding grooves for sliding rods are opened at the upper ends of both sides of the inner cavity of the column. A pull ring is fixedly connected to the upper end of the column.

[0009] Furthermore, the telescopic fence includes an inner fence and an outer fence. Two sets of screws are welded on the inner fence, and each set of screws is threaded with a locking nut that abuts against the outer fence.

[0010] Furthermore, the inner fence includes a rectangular frame, within which multiple sets of railings are welded. Each set of railings has a warning reflective strip attached to its outer side. The upper and lower surfaces of the rectangular frame are provided with first insertion holes for the insertion of pins and bolts.

[0011] Furthermore, the outer fence includes a mounting frame and two sets of sliding frames. The two sets of sliding frames are respectively welded to both ends of the mounting frame, and multiple sets of railings are welded to the opposite side of each of the two sets of sliding frames. The two sets of sliding frames are respectively slidably mounted on the rectangular frame.

[0012] Furthermore, each of the two sets of sliding frames has an adjustment groove on one side for the screw to slide, and each of the two ends of the mounting frame has a second insertion hole for the pin shaft and the plug to be inserted. The mounting frame is arranged in a U-shape.

[0013] Furthermore, the base includes an anti-slip base plate welded to the lower end of the column, and the anti-slip base plate has a guide groove and two sets of stepped grooves. An extension frame located in the two sets of stepped grooves is installed in the guide groove, and a gear that meshes with the two sets of extension frames is rotatably arranged in the guide groove.

[0014] Furthermore, the extension frame includes a support plate, a rack, and a guide rod. The rack and the guide rod are both welded to one side of the support plate. The rack is inserted into a guide groove, and the guide rod is inserted into a stepped groove. A magnet is fixedly connected to one end of the guide rod. Two sets of fixing ears are welded to the other side of the support plate.

[0015] The beneficial effects of this invention are: 1. This invention, through the cooperation of the support frame, connecting mechanism, and telescopic fence, allows for convenient support of both ends of the telescopic fence via the support frame, and facilitates adjustment of the spacing between adjacent support frames according to the protection range. Simultaneously, the telescopic fence can adjust its angle with the support frame according to the protection requirements of the construction site, thus allowing for convenient adjustment of the protection range based on the terrain. Furthermore, the connecting mechanism further ensures the stability of the telescopic fence installation, improving the flexibility of protection at the construction site. It is particularly convenient for use in construction sites with corners, enhancing ease of use. 2. The present invention utilizes the cooperation between the base and the support frame. The base provides a stable support foundation for the support frame, thereby ensuring the stability of the support frame when it is placed. At the same time, the base further increases the contact area with the ground by extending the extension frame, further improving the stability of the support and thus preventing the fence from tipping over after it is extended, thereby improving the protective stability of the protective fence for the construction site. 3. This invention utilizes the cooperation of the inner and outer fences of the telescopic fence. The outer fence can slide outside the inner fence, thereby adjusting the protection range according to the construction protection requirements. This makes it suitable for construction sites in different scenarios. Furthermore, the telescopic fence can be flipped on the support frame, making it easy to adjust the angle between adjacent sets of telescopic fences to suit corner scenarios on construction sites, thus improving its applicability.

[0016] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the overall unfolded structure according to an embodiment of the present invention is shown; Figure 2 A schematic diagram of a telescopic fence structure according to an embodiment of the present invention is shown; Figure 3 A schematic diagram of the inner fence structure according to an embodiment of the present invention is shown; Figure 4 A schematic diagram of the outer fence structure according to an embodiment of the present invention is shown; Figure 5 A schematic diagram of the base structure according to an embodiment of the present invention is shown; Figure 6 A schematic diagram of a support frame structure according to an embodiment of the present invention is shown; Figure 7 A schematic diagram of the connection mechanism structure according to an embodiment of the present invention is shown.

[0019] In the diagram: 1. Support frame; 11. Column; 12. Reinforcing beam; 13. Slide groove; 14. Support base; 15. Pin; 2. Base; 21. Anti-slip base plate; 22. Guide groove; 23. Step groove; 24. Gear; 25. Extension frame; 251. Support plate; 252. Rack; 253. Guide rod; 254. Fixing lug; 255. Magnet; 3. Connecting mechanism; 31. Upright; 32. Limiting plate; 33. Pin; 34. Slide rod; 35. Spring; 36. Pull ring; 4. Telescopic fence; 41. Inner fence; 411. Rectangular frame; 412. Railing; 413. First insertion hole; 42. Outer fence; 421. Mounting frame; 422. Second insertion hole; 423. Slide frame; 424. Balustrade; 425. Adjustment groove; 43. Screw; 44. Locking nut. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] As shown in Figures 1-7, this embodiment of the invention provides a protective fence for construction, including two sets of support frames 1 and a telescopic fence 4 installed between the two sets of support frames 1. The lower ends of the two sets of support frames 1 are fixedly connected to bases 2, and the two sets of support frames 1 are each connected to a connecting mechanism 3 that limits the telescopic fence 4. The telescopic fence 4 can be rotated around the support frames 1 as the axis. By installing the telescopic fence 4 on the support frames 1, the telescopic fence 4 can be adjusted at a certain angle.

[0022] In this embodiment, the support frame 1 includes a column 11, both sides of the column 11 are open, and both sides of the inner cavity of the column 11 are welded with reinforcing beams 12. Two sets of support seats 14 for supporting the telescopic fence 4 are fixedly connected to the bottom of the inner cavity of the column 11, and pins 15 for the telescopic fence 4 to rotate are welded on the support seats 14. The openings on both sides of the post 11 facilitate the assembly and disassembly of the telescopic fence 4, thereby making the assembly and disassembly of the protective fence easier and improving the convenience of assembly and disassembly. The reinforcing beam 12 inside the post 11 can improve the overall structural strength of the post 11, thereby avoiding deformation caused by collisions during construction and improving its service life. The support base 14 and the pin 15 can provide a stable rotation fulcrum for the telescopic fence 4, thereby ensuring that the telescopic fence 4 can smoothly achieve angle flipping adjustment. The telescopic fence 4 can be flipped from -45 degrees to 45 degrees with the pin 15 to suit different construction scenarios. Both the column 11 and the reinforcing beam 12 are made of hot-rolled steel plates, and the column 11 is 1.2-1.5m high and has a rectangular cross-section when viewed from above.

[0023] Furthermore, the connecting mechanism 3 includes a pole 31 that passes through the upper end of the column 11, a limiting plate 32 that is fixedly connected to the lower end of the pole 31, a pin 33 that is fixedly connected to the lower surface of the limiting plate 32 and inserted into the telescopic fence 4, and a spring 35 that is sleeved on the outside of the pole 31 on the upper surface of the limiting plate 32. The cooperation of the upright post 31, the limiting plate 32 and the pin 33 enables the telescopic fence 4 to be quickly inserted and limited to the support frame 1, preventing the telescopic fence 4 from detaching during use. The spring 35 can generate a continuous downward force on the limiting plate 32, ensuring that the pin 33 is tightly inserted into the telescopic fence 4 and is not easy to fall off. At the same time, it is easy to pull the upright post 31 to release the pin 33, making it convenient to disassemble the telescopic fence 4 and improving the flexibility of the fence. The outer diameters of the pin 33 and the pin 15 are both smaller than the outer diameter of the first insertion hole 413, while the outer diameters of the limiting plate 32 and the support base 14 are both larger than the outer diameter of the first insertion hole 413. This facilitates the installation of the telescopic fence 4 while restricting its position, thus improving the stability of the telescopic fence 4 installation. Both the ends of the pin 33 and the pin shaft 15 are rounded to facilitate insertion into the first insertion hole 413. Meanwhile, the spring 35 is a cylindrical helical compression spring 35 with a wire diameter of 2-3mm, an inner diameter of 12-14mm, and a free length of 30-40mm. The upper end of the spring 35 abuts against the top of the inner cavity of the column 11 to ensure that the spring 35 can stably provide elastic force.

[0024] Secondly, two sets of sliding rods 34 are fixedly connected to the outer side of the limiting plate 32. The upper ends of both sides of the inner cavity of the column 11 are provided with sliding grooves 13 for the sliding rods 34 to slide. The upper end of the column 31 is fixedly connected with a pull ring 36. The extension direction of the sliding groove 13 is parallel to the axis of the column 11. The two ends of the sliding groove 13 are provided with arc chamfers to prevent the sliding rods 34 from getting stuck when sliding. The sliding rod 34 and the sliding groove 13 guide the up and down sliding of the limiting plate 32, preventing the limiting plate 32 from rotating during the sliding process, ensuring that the pin 33 can be accurately aligned with the insertion hole of the telescopic fence 4, and improving the smooth operation of the connecting mechanism 3. The pull ring 36 provides a convenient force point for pulling the upright 31. Without the need for additional tools, the upright 31 can be easily pulled to disengage the pin 33, further improving the ease of operation of the fence. At the same time, the pull ring 36 can also serve as an auxiliary hanging point, making it convenient to hang warning signs, safety slogans, etc.

[0025] Specifically, the telescopic fence 4 includes an inner fence 41 and an outer fence 42. Two sets of screws 43 are welded on the inner fence 41, and both sets of screws 43 are threaded with locking nuts 44 that abut against the outer fence 42. The telescopic structure of the inner fence 41 and the outer fence 42, through the cooperation of the screw 43 and the locking nut 44, can flexibly adjust the overall length of the telescopic fence 4 to adapt to construction areas of different widths, thereby improving the versatility of the fence. The locking nut 44 can lock and fix the inner fence 41 and the outer fence 42 to ensure that the structure is stable after the telescopic fence 4 is adjusted to the correct position, and avoid the fence from loosening due to collisions, wind, or other factors during construction. At the same time, it is convenient to make secondary adjustments according to changes in the size of the construction area, thereby reducing construction costs. The locking nut 44 is a hexagonal nut that matches the screw 43. It is made of Q235 steel and has a galvanized surface. A rubber gasket (2-3mm thick) is provided at the contact point between the locking nut 44 and the outer fence 42 to enhance the locking effect and prevent wear on the surface of the outer fence 42. The part of the screw 43 located in the adjustment groove 425 has a smooth surface to prevent the screw threads from damaging the adjustment groove 425.

[0026] Preferably, the inner fence 41 includes a rectangular frame 411, and multiple sets of railings 412 are welded inside the rectangular frame 411. Warning reflective strips are attached to the outer side of each set of railings 412. The upper and lower surfaces of the rectangular frame 411 are provided with first insertion holes 413 for the insertion of pin shaft 15 and pin 33. The rectangular frame 411 provides a stable installation base for the railing 412. Multiple railings 412 are evenly distributed to enhance the protective strength of the inner fence 41, effectively blocking personnel from passing through and ensuring construction safety. The reflective strips reflect light in low light conditions (such as nighttime construction or cloudy days), providing a clear warning and reminding passersby to avoid the area, thus reducing the accident rate. The first insertion hole 413 ensures that the inner fence 41 can accurately engage with the pin 15 of the support frame 1 and the pin 33 of the connecting mechanism 3, enabling rapid installation and positioning. The railing 412 is set in 6-8 groups, evenly distributed, with a spacing of 150-200mm and a diameter of 18-20mm. The railing 412 is connected to the rectangular frame 411 by welding. The weld is treated with anti-rust treatment. The warning reflective strip is made of high-brightness reflective film with a thickness of 0.1-0.2mm. It is pasted on the outside of the railing 412 and is glued with strong waterproof adhesive to ensure that it is not easy to fall off. The diameter of the first insertion hole 413 is adapted to the pin 15 and the pin 33, with a gap of 0.5-1mm. The edge of the first insertion hole 413 is chamfered to facilitate insertion.

[0027] Secondly, the outer fence 42 includes a mounting frame 421 and two sets of sliding frames 423. The two sets of sliding frames 423 are welded to both ends of the mounting frame 421, and multiple sets of guardrails 424 are welded to the opposite side of the two sets of sliding frames 423. The two sets of sliding frames 423 are slidably mounted on the rectangular frame 411. The sliding cooperation between the sliding frame 423 and the rectangular frame 411 enables smooth extension and retraction of the inner fence 41 and the outer fence 42, ensuring no jamming during the extension and retraction adjustment. The setting of multiple sets of guardrails 424 further enhances the protective performance of the outer fence 42, fills the gap between the guardrails 412, and enhances the overall rigidity of the fence. The sliding frame 423 is welded to both ends of the mounting frame 421 to ensure the structural stability of the outer fence 42, prevent deformation and loosening during the extension and retraction process, and extend the service life of the fence.

[0028] Specifically, each of the two sets of sliding frames 423 has an adjustment groove 425 on one side for the screw 43 to slide, and each of the two ends of the mounting frame 421 has a second insertion hole 422 for the pin shaft 15 and the pin 33 to be inserted. The mounting frame 421 is arranged in a U-shape. The adjustment groove 425 provides sliding space for the screw 43, ensuring that the screw 43 does not affect the telescopic operation when the outer fence 42 is telescopically adjusted, and also serves as a limit for the screw 43. The second insertion hole 422 ensures that the outer fence 42 can cooperate with the pin 15 and the pin 33. When the telescopic fence 4 is adjusted to its maximum length, the outer fence 42 can be fixed to the support frame 1 through the pin 33, further improving the overall stability of the fence. The design of the C-shaped mounting frame 421 facilitates the installation of the sliding frame 423 and the guardrail 424, while reducing the overall weight of the outer fence 42, making it easier to transport and install.

[0029] It is worth noting that the base 2 includes an anti-slip base plate 21 welded to the lower end of the column 11, and the anti-slip base plate 21 is provided with a guide groove 22 and two sets of stepped grooves 23. An extension frame 25 located in the two sets of stepped grooves 23 is installed in the guide groove 22, and a gear 24 that meshes with the two sets of extension frames 25 is rotatably arranged in the guide groove 22. The base 2 adopts an anti-slip base plate 21 design, which increases the contact area with the ground and improves the anti-slip performance of the fence. This prevents the fence from sliding or tipping over due to factors such as smooth ground or collisions during construction. The guide groove 22, the stepped groove 23, the extension frame 25, and the gear 24 work together to achieve synchronous extension and retraction of the extension frame 25. By adjusting the extension length of the extension frame 25, the support area of ​​the base 2 is further increased, which improves the stability of the fence in windy environments. The extension frame 25 is hidden in the stepped groove 23 and does not occupy extra space when not in use, making it convenient for the fence to be moved and stored.

[0030] In addition, the extension frame 25 includes a support plate 251, a rack 252 and a guide rod 253. The rack 252 and the guide rod 253 are both welded to one side of the support plate 251. The rack 252 is inserted into the guide groove 22, and the guide rod 253 is inserted into the stepped groove 23. A magnet 255 is fixedly connected to one end of the guide rod 253. Two sets of fixing ears 254 are welded to the other side of the support plate 251. The support plate 251 increases the contact area between the extension frame 25 and the ground, further improving the support stability. The rack 252 cooperates with the gear 24 to realize the synchronous extension and retraction of the extension frame 25, which is convenient to operate. The guide rod 253 cooperates with the stepped groove 23 to guide the extension and retraction of the extension frame 25, preventing the extension frame 25 from shifting or getting stuck during extension and retraction. The magnet 255 can make the extension frame 25 adhere and fix it to the anti-slip base plate 21 after retraction, preventing the extension frame 25 from accidentally extending during transportation and handling. The setting of the fixing ear 254 makes it easy to fix the extension frame 25 to the ground with bolts, which is suitable for construction scenarios with soft ground, further improving the stability of the fence.

[0031] In use, first place the two sets of support frames 1 in the predetermined position in the construction area through the base 2. Depending on the ground conditions, pull the handle on the support plate 251 to drive the two sets of extension frames 25 to extend synchronously, increasing the support area of ​​the base 2. If the ground is soft, the base 2 can be fixed to the ground with bolts through the fixing ears 254 on the extension frame 25. If the ground is flat, the anti-slip texture of the anti-slip base plate 21 can be used directly to achieve anti-slip positioning, ensuring that the support frame 1 is stable and upright. Then adjust the length of the telescopic fence 4. Adjust the inner fence 41 and outer fence 42 of the telescopic fence 4 according to the width of the construction area. Push the outer fence 42 to slide along the rectangular frame 411 of the inner fence 41. After the telescopic fence 4 reaches the required length, tighten the locking nut 44 on the screw 43 to lock the inner fence 41 and outer fence 42. Then pull the pull ring 36 on the support frame 1 to drive the upright 31 to move upward. The upright 31 drives the limit plate 32 to compress the spring 35, so that the pin 33 is lifted upward. First, install the first insertion hole 413 of the telescopic fence 4 with a set of pins 33 and pins 15. Then align the second insertion hole 422 with another set of pins 15 and pins 33 to complete the connection and limit of the telescopic fence 4 and the support frame 1. When the protective angle needs to be adjusted, the installation position of the post 11 is adjusted. That is, the telescopic fence 4 can be flipped to the required angle with the pin 15 as the axis to adapt to the corner scene of the construction area.

[0032] After construction is completed, pull the ring 36 to release the pin 33 limit, remove the telescopic fence 4 from the support frame 1, loosen the locking nut 44, retract the outer fence 42 into the inner fence 41 to reduce the size of the fence, and at the same time rotate the gear 24 to retract the extension frame 25 into the stepped groove 23. Then, the support frame 1 and the telescopic fence 4 are transported separately for easy storage and reuse.

[0033] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protective fence for construction work, characterized in that, include: Two sets of support frames (1) and a telescopic fence (4) installed between the two sets of support frames (1). The lower ends of the two sets of support frames (1) are fixedly connected to bases (2). The two sets of support frames (1) are each connected to a connecting mechanism (3) that limits the telescopic fence (4). The telescopic fence (4) can be rotated with the support frame (1) as the axis. By installing the telescopic fence (4) on the support frame (1), the telescopic fence (4) can be adjusted at a certain angle.

2. The protective fence for construction work according to claim 1, characterized in that: The support frame (1) includes a column (11), both sides of which are open. Both sides of the inner cavity of the column (11) are welded with reinforcing beams (12). Two sets of support seats (14) for supporting the telescopic fence (4) are fixedly connected to the bottom of the inner cavity of the column (11), and pins (15) for the telescopic fence (4) to rotate are welded on the support seats (14).

3. A protective fence for construction work according to claim 2, characterized in that: The connecting mechanism (3) includes a pole (31) that passes through the upper end of the column (11). The lower end of the pole (31) is fixedly connected to a limiting plate (32). The lower surface of the limiting plate (32) is fixedly connected to a pin (33) that is inserted into the telescopic fence (4). The upper surface of the limiting plate (32) is provided with a spring (35) sleeved on the outside of the pole (31).

4. A protective fence for construction work according to claim 3, characterized in that: Two sets of sliding rods (34) are fixedly connected to the outer side of the limiting plate (32). The upper ends of both sides of the inner cavity of the column (11) are provided with sliding grooves (13) for sliding rods (34) to slide. The upper end of the column (31) is fixedly connected with a pull ring (36).

5. A protective fence for construction work according to claim 4, characterized in that: The telescopic fence (4) includes an inner fence (41) and an outer fence (42). Two sets of screws (43) are welded on the inner fence (41), and both sets of screws (43) are threaded with locking nuts (44) that abut against the outer fence (42).

6. A protective fence for construction work according to claim 5, characterized in that: The inner fence (41) includes a rectangular frame (411), and multiple sets of railings (412) are welded inside the rectangular frame (411). Warning reflective strips are attached to the outer side of each set of railings (412). The upper and lower surfaces of the rectangular frame (411) are provided with first insertion holes (413) for the insertion of pin shafts (15) and pins (33).

7. A protective fence for construction work according to claim 6, characterized in that: The outer fence (42) includes an installation frame (421) and two sets of sliding frames (423). The two sets of sliding frames (423) are respectively welded to both ends of the installation frame (421), and multiple sets of railings (424) are welded to the opposite side of the two sets of sliding frames (423). The two sets of sliding frames (423) are respectively slidably set on the rectangular frame (411).

8. A protective fence for construction work according to claim 7, characterized in that: Both sets of sliding frames (423) have an adjustment groove (425) on one side for the screw (43) to slide, and both ends of the mounting frame (421) have a second insertion hole (422) for the pin shaft (15) and the pin (33) to be inserted. The mounting frame (421) is arranged in a U-shape.

9. A protective fence for construction work according to claim 8, characterized in that: The base (2) includes an anti-slip base plate (21) welded to the lower end of the column (11), and the anti-slip base plate (21) is provided with a guide groove (22) and two sets of stepped grooves (23). An extension frame (25) located in the two sets of stepped grooves (23) is installed in the guide groove (22), and a gear (24) that meshes with the two sets of extension frames (25) is rotatably provided in the guide groove (22).

10. A protective fence for construction work according to claim 9, characterized in that: The extension frame (25) includes a support plate (251), a rack (252), and a guide rod (253). The rack (252) and the guide rod (253) are both welded to one side of the support plate (251). The rack (252) is inserted into the guide groove (22), and the guide rod (253) is inserted into the stepped groove (23). A magnet (255) is fixedly connected to one end of the guide rod (253). Two sets of fixing ears (254) are welded to the other side of the support plate (251).

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