Magnetic orientation steel fiber 3D printing concrete quick release slip form nozzle supporting manual feeding

Abstract

The invention discloses a magnetic orientation steel fiber 3D printing concrete quick release slip form nozzle supporting manual feeding, and belongs to the field of additive manufacturing. Comprising an anti-gravity printing module for controlling a spiral extrusion structure to rotate by utilizing a power output structure so as to convey concrete to a spray head at an outlet of a hopper in an anti-gravity manner; the magnetic orientation module is used for generating magnetic force along the axis direction of the spray head; and the sliding formwork module is used for providing temporary support for 3D printing concrete in the lining repairing process and restraining the concrete extruded by the spray head in a cavity formed between a sliding formwork and a lining. The anti-gravity printing module solves the problem that manual feeding is incompatible with a traditional concrete repairing lining method based on 3D printing, the magnetic orientation module avoids winding of steel fibers and achieves quick disassembly and quick change of a spray head, and the sliding formwork module provides temporary support; and the possibility of stripping and falling of the 3D printing concrete on the tunnel vault in the anti-gravity direction is reduced, and good application prospects are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of additive manufacturing, and in particular relates to a magnetically oriented steel fiber 3D printing concrete quick-release slipform nozzle that supports manual feeding. Background Art

[0002] During underground construction, the lining is a permanent support structure constructed of reinforced concrete and other materials along the perimeter of a tunnel to prevent deformation or collapse of the surrounding rock. The lining's structural stability and mechanical durability are prerequisites for the efficient construction of tunnels capable of withstanding long-term loads and external forces such as earthquakes. 3D-printed concrete, due to its efficiency and flexibility, is becoming a mainstream repair technology, enabling precise repairs through parameter control.

[0003] Currently, the application of 3D-printed concrete in lining repair requires not only a printing system, motion system, and control system, but also a complete set of supporting systems, including a mixing system and a conveying system. Mixing and conveying systems typically occupy a large amount of space, making them incompatible with small-diameter tunnel lining repair operations. For lining repair projects with limited budgets, mixing and conveying systems will incur significant economic costs. Manual feeding not only saves on the purchase of conveying systems but also allows for real-time adjustment of the amount of concrete delivered during lining repair operations based on actual conditions. After the lining repair operation is completed, construction workers do not need to clean the conveying system, reducing their workload. However, manual feeding currently only allows the printing system to 3D print concrete in the direction of gravity, and cannot achieve both manual feeding and 3D printing concrete against gravity.

[0004] Concrete is a brittle material, and using it alone for lining repairs is prone to cracking and lacks ductility. Although current projects have proposed the introduction of steel fibers to enhance the mechanical properties of lining repairs, the random orientation and distribution of steel fibers in concrete reduces these properties. The random orientation of steel fibers can also easily form overlapping networks within the nozzle, potentially clogging the nozzle and causing printing failures. Furthermore, nozzles of varying diameters are often required to address different tunnel lining damage conditions. However, the nozzle and hopper are currently typically connected using threads. Cement and fine sand particles in the concrete can easily penetrate into the thread gaps during the lining repair process, causing frictional self-locking and making nozzle replacement difficult. Furthermore, because 3D-printed concrete operates by rotating a spiral extruder driven by a motor to extrude concrete, unlike shotcreting, the concrete is subjected to less pressure during extrusion. 3D-printed concrete, applied against gravity, inevitably causes some concrete to peel and fall onto the tunnel vault, polluting the construction environment and increasing material costs. Summary of the Invention

[0005] In response to the above problems, the present invention proposes a magnetically oriented steel fiber 3D printing concrete quick-release slipform nozzle that supports manual feeding.

[0006] The technical solutions of the present invention are as follows:

[0007] A magnetically oriented steel fiber 3D printing concrete quick-release slipform nozzle that supports manual feeding, comprising:

[0008] The anti-gravity printing module is installed at the end of the robotic arm and includes a spiral extrusion structure, a power output structure, and a hopper. The spiral extrusion structure is installed in the hopper, the feed port of the hopper is tilted upward, and the material is stored at the bottom of the hopper. The power output structure is used to control the rotation of the spiral extrusion structure to transport concrete against gravity to the nozzle at the hopper outlet;

[0009] The magnetic orientation module includes a magnetic assembly and a nozzle. The nozzle is installed at the outlet of the hopper through the magnetic assembly, and the magnetic assembly generates a magnetic force along the axis of the nozzle.

[0010] The sliding formwork module includes a sliding formwork, an isolation belt and a demoulding vibrator. The sliding formwork is sleeved on the outer wall of the nozzle outlet, the isolation belt is bonded to the outer surface of the sliding formwork, and the demoulding vibrators are evenly arranged on the inner surface of the sliding formwork. The sliding formwork module is used to provide temporary support for 3D printed concrete during the lining repair process, and confine the concrete extruded by the nozzle to the cavity formed between the sliding formwork and the lining.

[0011] As a preferred embodiment of the present invention, the spiral extrusion structure includes a cylindrical anti-gravity conveying steel cylinder and a spiral extrusion rod coaxially installed inside the steel cylinder, and there is a radial gap between the two; the driving end of the spiral extrusion rod passes through the bottom of the hopper and is connected to the power output structure below the hopper, and the spiral extrusion rod is aligned with the top of the anti-gravity conveying steel cylinder and extends out of the top of the hopper.

[0012] As a preferred embodiment of the present invention, the hopper includes a cylindrical cavity at the top and an inverted conical cavity at the bottom, the feed port of the hopper is inclined upward and connected to the cylindrical cavity, and the conveying starting end of the spiral extrusion structure is close to the bottom of the inverted conical cavity.

[0013] As a preferred embodiment of the present invention, the power output structure includes a stepper motor, which is fixed below the hopper via a mounting base, and the output shaft of the stepper motor is connected to the driving end of the spiral extrusion rod via a coupling.

[0014] As a preferred embodiment of the present invention, the driving end of the spiral extrusion rod is transitionally matched with the through hole on the hopper when passing through the bottom of the hopper, and is provided with a leak-proof sealing ring.

[0015] As a preferred embodiment of the present invention, a hollow plate is provided on the top of the hopper, which is connected to the inside of the hopper to form a recovery trough; the steel cylinder for transporting against gravity is fixed by the hollow plate and its supporting auxiliary plate inside the hopper.

[0016] As a preferred embodiment of the present invention, the magnetic assembly in the magnetic orientation module includes a magnet bracket, a first annular permanent magnet and a second annular permanent magnet. The magnet bracket is mounted on the outer wall of the steel cylinder for transporting against gravity. The first annular permanent magnet is installed in an annular groove on the lower end face of the magnet bracket, and the second annular permanent magnet is installed in an annular groove on the upper end face of the nozzle. The two permanent magnets are axially magnetized and the end faces have opposite magnetic poles, and the nozzle is adsorbed on the magnet bracket by magnetic force.

[0017] As a preferred embodiment of the present invention, the sliding template is a curved plate, the surface area of ​​which is larger than the diameter of the nozzle and does not block the recovery tank.

[0018] As a preferred embodiment of the present invention, the sliding template is arranged on the outer wall of the nozzle outlet through a connecting ring, the upper end face and inner wall of the connecting ring are respectively bonded to the inner surface of the sliding template and the outer wall of the nozzle, and a through hole matching the nozzle is provided in the center of the sliding template.

[0019] The beneficial effects of the present invention are:

[0020] (1) The present invention adopts the collaborative design of the anti-gravity printing module and the magnetic orientation module. The independently driven anti-gravity printing module is used to achieve anti-gravity printing while retaining the flexibility of manual operation, solving the problem of incompatibility between manual feeding and traditional 3D printing-based concrete repair lining methods; the magnetic orientation module generates a controllable magnetic field to guide the steel fibers to align in a directional manner during the flow of concrete, eliminating the risk of nozzle blockage caused by fiber cross-entanglement and ensuring the continuity of nozzle printing; in addition, the magnetic nozzle interface replaces the traditional threaded connection, completely solving the friction self-locking problem caused by cement particles invading the thread gap, and supporting rapid switching of nozzles of different diameters.

[0021] (2) The present invention adopts a linkage design of a recovery trough module and a sliding formwork module. The recovery trough collects concrete debris peeled off by gravity, and the collected debris enters the hopper for reuse, thereby reducing material waste and pollution to the construction environment; the sliding formwork module provides a continuous and smooth temporary support while repairing the lining based on 3D printed concrete, reducing the peeling and falling of 3D printed concrete on the tunnel vault in the direction against gravity. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a construction diagram of a magnetically oriented steel fiber 3D printing concrete quick-release slipform nozzle that supports manual feeding and is mounted on a six-degree-of-freedom robotic arm;

[0023] Figure 2 This is the overall structure diagram of the magnetically oriented steel fiber 3D printing concrete quick-release slipform nozzle that supports manual feeding;

[0024] Figure 3This is a cross-sectional view of a quick-release slipform nozzle for 3D printing concrete with magnetically oriented steel fibers that supports manual feeding.

[0025] Figure 4 This is an exploded view of the gravity-defying printing module;

[0026] Figure 5 This is an exploded view of the gravity-defying printing module from another perspective;

[0027] Figure 6 This is a cross-sectional view of the gravity-defying printing module;

[0028] Figure 7 This is an exploded view of the magnetic orientation module;

[0029] Figure 8 This is an exploded view of the magnetic orientation module from another perspective;

[0030] Figure 9 It is the structural diagram of the sliding template module;

[0031] Figure 10 This is the structural diagram of the sliding template module from another perspective;

[0032] Figure 11 is a schematic diagram of a filament obtained by printing in a specific implementation;

[0033] In the figure, 1-lining to be repaired, 2-six-degree-of-freedom robotic arm, 3-anti-gravity printing module, 4-magnetic orientation module, 5-connecting ring, 6-sliding template module, 301-stepping motor, 302-motor support seat, 303-rigid coupling, 304-screw extrusion rod, 305-fixed mounting frame, 306-leakage-proof sealing ring, 307-hopper, 308-feed port, 309-anti-gravity conveying steel cylinder, 310-support auxiliary plate, 311-recovery trough, 401-magnet bracket, 402-first annular permanent magnet, 403-second annular permanent magnet, 404-nozzle, 601-sliding template, 602-isolation belt, 603-demolding vibrator. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0035] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0036] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0037] The accompanying drawings show various structural schematic diagrams of the embodiments disclosed in the present invention. These drawings are not drawn to scale, and some details are exaggerated and may be omitted for the purpose of clarity.

[0038] The proposed manual-feed, magnetically oriented steel fiber 3D-printed concrete quick-release slipform nozzle focuses on a key aspect of tunnel lining construction: lining repair. This invention aims to address the incompatibility between manual feeding and traditional 3D-printed concrete lining repair methods. It also aims to improve the printing performance of 3D-printed steel fiber concrete, enable quick-release and quick-change nozzles of varying diameters, and mitigate the potential for concrete peeling and falling during 3D printing on tunnel vaults. This manual-feed, magnetically oriented steel fiber 3D-printed concrete quick-release slipform nozzle offers several advantages: First, a gravity-resistant steel cylinder ensures the rigidity of the entire printing module during the repair process, successfully resolving the incompatibility issue between manual feeding and traditional 3D-printed concrete lining repair methods. It supports manual feeding while enabling gravity-resistant 3D printing of concrete for lining repair. Second, a recovery trough on the gravity-resistant printing module allows concrete that has peeled and fallen from the tunnel vault to be reclaimed by the gravity-resistant printing module, reducing material waste and environmental pollution. Third, the magnetic orientation module is used to prevent steel fibers from crossing or even entangled with each other inside the 3D printing concrete nozzle, thereby forming an overlapping mesh structure and causing printing failure, thereby greatly improving the printing performance of steel fiber concrete; fourth, the design of the magnetic orientation module abandons the design of threaded connection between the traditional nozzle and the hopper, eliminating the possibility of cement and fine sand particles in the concrete sneaking into the thread gap to form friction self-locking during the lining repair process, and realizing the quick disassembly and replacement of nozzles of different diameters; fifth, the setting of the sliding formwork module provides a continuous and smooth temporary support while repairing the lining based on 3D printing concrete. The extruded concrete will be constrained in the cavity formed between the sliding formwork and the lining, thereby reducing the possibility of 3D printed concrete peeling and falling in the tunnel vault against the direction of gravity. At the same time, the use of permanent magnets to achieve magnetic orientation of steel fibers in concrete solves the problems of uneven concrete coagulation and energy loss that can occur when conventional coils are heated by electromagnetic heating, improving the reliability of lining repairs while achieving energy savings. Furthermore, the present invention has good scalability, facilitating the use of newly developed composite nozzles for research on gravity-defying 3D-printed concrete lining repairs, and has promising application prospects in optimizing the stability of tunnel lining repairs and regulating mechanical properties. In summary, the present invention has great potential for simplifying the lining repair process and efficiently constructing long-term, stable tunnels.

[0039] like Figure 2-3 As shown in the figure, the present invention proposes a magnetically oriented steel fiber 3D printing concrete quick-release sliding formwork nozzle that supports manual feeding. It mainly consists of three parts: a gravity-resistant printing module, a magnetic orientation module, and a sliding formwork module. In actual use, it is mounted on a six-degree-of-freedom robotic arm. The construction diagram is shown in the figure. Figure 1As shown, the six-degree-of-freedom robotic arm 2 is positioned beneath the lining to be repaired 1. The anti-gravity printing module 3 is threadedly connected to the six-degree-of-freedom robotic arm 2 via circumferential threaded holes on the end flange. The magnetic orientation module 4 is directly welded to the anti-gravity printing module 3. Welding glue is applied to both connecting surfaces of the connecting ring 5: one connecting surface is connected to the magnetic orientation module 4, and the other connecting surface is connected to the sliding template module 6. The anti-gravity printing module 3, magnetic orientation module 4, and sliding template module 6 are arranged along their axes, which always coincide with the normal of the lining to be repaired 1.

[0040] Among them, the anti-gravity printing module is installed at the end of the robotic arm, and includes a spiral extrusion structure, a power output structure and a hopper 307. The spiral extrusion structure is installed in the hopper 307, the feed port 308 of the hopper 307 is tilted upward and the material is stored at the bottom of the hopper 307. The power output structure is used to control the rotation of the spiral extrusion structure to fight against gravity and transport concrete to the nozzle 404 at the outlet position of the hopper 307; it is mainly responsible for controlling the rotation of the spiral extrusion rod to fight against gravity and transport concrete to the nozzle.

[0041] The magnetic orientation module includes a magnetic component and a nozzle 404. The nozzle 404 is installed at the outlet of the hopper 307 through the magnetic component, and the magnetic component generates a magnetic force along the axis of the nozzle 404. It is mainly responsible for completing the magnetic orientation of steel fibers inside the 3D printing nozzle, while improving the printing performance of steel fiber concrete, and realizing the quick disassembly and replacement function of nozzles of different diameters.

[0042] The sliding formwork module includes a sliding formwork 601, an isolation belt 602, and a demolding vibrator 603. The sliding formwork 601 is mounted on the outer wall of the nozzle 404 outlet, the isolation belt 602 is bonded to the outer surface of the sliding formwork 601, and the demolding vibrators 603 are evenly distributed on the inner surface of the sliding formwork 601. The sliding formwork module is used to provide temporary support for the 3D-printed concrete during the lining repair process, confining the concrete extruded by the nozzle 404 in the cavity formed between the sliding formwork and the lining, thereby reducing the possibility of the 3D-printed concrete peeling and falling. In addition, the magnetically oriented steel fiber 3D-printed concrete quick-release sliding formwork nozzle, which supports manual feeding, is mounted on a six-degree-of-freedom robotic arm, whose movement is controlled by the robotic arm.

[0043] In one embodiment of the present invention, the anti-gravity printing module 3 is shown in an exploded view. Figure 4 As shown, another exploded view is as follows Figure 5 As shown, the cross-sectional view is Figure 6As shown, the anti-gravity printing module 3 primarily comprises a stepper motor 301, a motor support 302, a rigid coupling 303, a screw extrusion rod 304, a fixed mounting bracket 305, a leak-proof seal 306, a hopper 307, a feed port 308, an anti-gravity conveying steel cylinder 309, a supporting auxiliary plate 310, and a recovery trough 311. The main structure, the hopper 307, comprises a cylindrical cavity at the top and an inverted conical cavity at the bottom. The feed port of the hopper 307 is angled upward and connected to the cylindrical cavity. The starting point of the screw extrusion structure is located near the bottom of the inverted conical cavity. The cylindrical anti-gravity conveying steel cylinder 309 and the screw extrusion rod 304, which is coaxially mounted within the cylinder, are coaxially fixed within the hopper 307. The stepper motor 301 is threadedly connected to the motor support 302. Its output shaft is connected to the screw extrusion rod 304 via a rigid coupling 303. A small hole is provided in the hopper 307 for the polished rod at the end of the screw extrusion rod 304 to pass through. The diameter of this hole is designed to form a transitional fit with the designed diameter of the polished rod at the end of the screw extrusion rod 304. To prevent concrete from leaking through the gap between the hopper 307 and the screw extrusion rod 304 during actual use of the gravity-defying printing module, affecting the normal operation of the stepper motor 301, a leak-proof sealing ring 306 is installed on the polished rod at the end of the screw extrusion rod 304. The motor support 302, the fixed mounting bracket 305, and the hopper 307 are connected by bolts and nuts. A hollow plate is also provided on the top of the hopper 307, communicating with the interior of the hopper 307 to form a recovery trough 311. The anti-gravity conveying steel cylinder 309 is fixed by the hollow plate and its supporting auxiliary plate inside the hopper 307. The anti-gravity conveying steel cylinder 309 is arranged outside the screw extrusion rod 304, with their axes coinciding with each other. A certain distance exists between the inner diameter of the anti-gravity conveying steel cylinder 309 and the outer diameter of the screw extrusion rod 304 blades to prevent the screw extrusion rod 304 blades from scraping the inner wall of the anti-gravity conveying steel cylinder 309 during lining repair. To prevent the anti-gravity conveying steel cylinder 309 from forming a "cantilever beam" structure due to lack of support at the end during actual construction, supporting auxiliary plates 310 are arranged at equal angles along the circumference of the outer wall of the anti-gravity conveying steel cylinder 309. One end of the supporting auxiliary plate 310 is welded to the inner wall of the hopper 307, and the other end is welded to the outer wall of the anti-gravity conveying steel cylinder 309. Recovery grooves 311 are provided at equal angles in the circumferential direction on the upper end surface of the hopper 307 , which can recycle the concrete peeled off and dropped from the tunnel vault into the hopper 307 , thus reducing material waste and pollution to the construction environment.

[0044] The exploded view of the magnetic orientation module 4 is as follows Figure 7 As shown, another exploded view is as follows Figure 8As shown. The magnetic orientation module 4 mainly includes a magnet holder 401, a first annular permanent magnet 402, a second annular permanent magnet 403, and a nozzle 404. The magnet holder 401 is directly sleeved on the outer wall of the anti-gravity conveying steel cylinder 309 of the anti-gravity printing module 3, and is directly connected to the anti-gravity conveying steel cylinder 309 by welding. An annular groove is provided on the end face of the magnet holder 401, and the first annular permanent magnet 402 is bonded to the annular groove on the magnet holder 401 by quick-drying glue. An annular groove is provided on the end face of the nozzle 404, and the second annular permanent magnet 403 is bonded to the annular groove on the nozzle 404 by quick-drying glue. The first annular permanent magnet 402 and the second annular permanent magnet 403 are axially magnetized before installation, and the end faces have opposite magnetic poles to realize the quick release and quick replacement function of the nozzle.

[0045] The structure diagram of sliding template module 6 is as follows Figure 9 As shown, another perspective structure diagram is as follows Figure 10 As shown. The sliding template module 6 mainly includes a sliding template 601, an isolation belt 602, and a demoulding vibrator 603. The sliding template 601 is sleeved on the outer wall of the nozzle 404 outlet, and is connected to the nozzle 404 by applying welding glue on the two connecting surfaces of the connecting ring 5. The isolation belt 602 is bonded to the outer surface of the sliding template 601 by quick-drying glue, so that wear occurs between the concrete and the isolation belt 602, preventing direct damage to the sliding template 601 itself. The demoulding vibrator 603 is evenly arranged in the grooves opened on the inner surface of the sliding template 601, and is connected to the sliding template 601 by bolts. The demoulding vibrator 603 helps to demould the sliding template module 6 from the 3D printed concrete.

[0046] The printing process of the above-mentioned magnetically oriented steel fiber 3D printing concrete quick-release slipform nozzle with manual feeding is as follows:

[0047] A six-degree-of-freedom robotic arm 2 drives a magnetically oriented steel fiber 3D printing concrete quick-release slipform nozzle, which supports manual feeding, to the bottom of the lining 1 to be repaired. Steel fiber concrete material is manually added through the feed port 308 and deposited into the conical cylinder below the hopper 307. A spiral extrusion rod 304 rotates, driven by a stepper motor 301. Its rotational speed is controlled by a signal input from the control system to the stepper motor 301. Under the extrusion action of the spiral extrusion rod 304, the steel fiber concrete material is fed into a gravity-resistant conveying cylinder 309. There, it is conveyed to the nozzle 404 under the restraint of the gravity-resistant conveying cylinder 309. At the nozzle 404, the steel fibers are magnetically oriented by the first and second annular permanent magnets 402 and 403, aligning them along the magnetic flux lines of the permanent magnets, thus preventing the steel fibers from crossing or even becoming entangled within the nozzle 404. As the spiral extrusion rod 304 rotates, concrete mixed with magnetically oriented steel fibers is extruded from the nozzle 404 onto the lining 1 to be repaired. The sliding template 601 provides a continuous and smooth temporary support at this time. The extruded steel fiber concrete will be constrained in the chamber formed between the sliding template 601 and the lining 1 to be repaired, thereby reducing the possibility of the 3D printed concrete peeling off and falling against the direction of gravity in the tunnel vault. As the six-degree-of-freedom robotic arm 2 drives the magnetically oriented steel fiber 3D printed concrete quick-release sliding template nozzle that supports manual feeding to form printed filaments, the demoulding vibrator 603 vibrates to achieve demoulding between the sliding template module and the 3D printed concrete. The shape of the printed filament in this embodiment is as follows: Figure 11 shown.

[0048] When it is necessary to replace a nozzle 404 of a different diameter for lining repair work, since the nozzle 404 is fixed to the nozzle bracket 401 by the magnetic attraction between the first annular permanent magnet 402 and the second annular permanent magnet 403, and the first annular permanent magnet 402 and the second annular permanent magnet 403 are small in size and have low magnetic permeability, the magnetic attraction between the two is relatively weak, so the nozzle can be easily removed, realizing quick disassembly and replacement of nozzles 404 of different diameters.

[0049] This invention utilizes a gravity-defying printing module to simultaneously support manual feeding and implement gravity-defying 3D printing of concrete for lining repair, resolving the incompatibility between manual feeding and traditional 3D-printed concrete lining repair methods. The gravity-defying printing module replaces the conveying system required by traditional 3D-printed concrete lining repair methods, saving the cost of purchasing the conveying system and eliminating the need for post-line repair cleaning, thus reducing the workload for construction personnel. The recycling trough design of this invention allows concrete that has fallen off the tunnel vault to be recycled, reducing material waste and environmental pollution. The magnetic orientation module prevents steel fibers from crossing or even entangled within the 3D-printed concrete nozzle, potentially forming an overlapping mesh structure and leading to printing failure, significantly improving the printing performance of steel fiber concrete. The magnetic orientation module also replaces the traditional threaded design between the nozzle and hopper, eliminating the possibility of cement and fine sand particles in the concrete penetrating the thread gaps and causing frictional self-locking during the lining repair process, while also enabling quick disassembly and replacement of nozzles of different diameters. Furthermore, the present invention utilizes sliding formwork modules to provide a continuous, smooth temporary support while simultaneously repairing the lining with 3D-printed concrete, reducing the likelihood of 3D-printed concrete peeling and falling against gravity in the tunnel vault. Furthermore, this invention provides excellent expansion opportunities for the performance verification of novel composite 3D printing nozzles, significantly aiding efficient and safe lining repair operations in practical engineering applications.

[0050] The above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples, and many variations are possible. All variations that can be directly derived or imagined by a person skilled in the art from the disclosure of the present invention should be considered to be within the scope of protection of the present invention.

Claims

1. A magnetically oriented steel fiber 3D printing concrete quick-release slipform nozzle that supports manual feeding, characterized in that: include: The anti-gravity printing module is installed at the end of the robot arm and includes a spiral extrusion structure, a power output structure and a hopper (307). The spiral extrusion structure is installed in the hopper (307). The feed port (308) of the hopper (307) is tilted upward and the bottom of the hopper (307) stores material. The power output structure is used to control the rotation of the spiral extrusion structure to transport concrete to the nozzle (404) at the outlet position of the hopper (307) against gravity. A magnetic orientation module comprises a magnetic assembly and a nozzle (404), wherein the nozzle (404) is installed at the outlet of the hopper (307) through the magnetic assembly, and the magnetic assembly generates a magnetic force along the axis direction of the nozzle (404); The sliding template module comprises a sliding template (601), an isolation belt (602) and a demoulding vibrator (603), wherein the sliding template (601) is sleeved on the outer wall of the nozzle (404) outlet, the isolation belt (602) is bonded to the outer surface of the sliding template (601), and the demoulding vibrator (603) is evenly arranged on the inner surface of the sliding template (601); the sliding template module is used to provide temporary support for 3D printed concrete during the lining repair process, and to constrain the concrete extruded by the nozzle (404) in the chamber formed between the sliding template and the lining.

2. The magnetically oriented steel fiber 3D printing concrete quick-release sliding form nozzle supporting manual feeding according to claim 1 is characterized in that: The spiral extrusion structure includes a cylindrical anti-gravity conveying steel cylinder (309) and a spiral extrusion rod (304) coaxially installed inside the steel cylinder, with a radial gap between the two; the driving end of the spiral extrusion rod (304) passes through the bottom of the hopper (307) and is connected to the power output structure below the hopper (307); the spiral extrusion rod (304) is aligned with the top of the anti-gravity conveying steel cylinder (309) and extends out of the top of the hopper (307).

3. The magnetically oriented steel fiber 3D printing concrete quick-release sliding form nozzle supporting manual feeding according to claim 2 is characterized in that: The hopper (307) includes a cylindrical cavity at the top and an inverted conical cavity at the bottom. The feed port of the hopper (307) is inclined upward and connected to the cylindrical cavity. The conveying starting end of the spiral extrusion structure is close to the bottom of the inverted conical cavity.

4. The magnetically oriented steel fiber 3D printing concrete quick-release sliding form nozzle supporting manual feeding according to claim 2, characterized in that: The power output structure includes a stepper motor (301), which is fixed below the hopper (307) via a mounting base, and an output shaft of the stepper motor (301) is connected to a driving end of a spiral extrusion rod (304) via a coupling.

5. The magnetically oriented steel fiber 3D printing concrete quick-release sliding form nozzle supporting manual feeding according to claim 4 is characterized in that: The driving end of the spiral extrusion rod (304) penetrates the bottom of the hopper (307) and is transitionally matched with the through hole on the hopper (307) and is provided with a leak-proof sealing ring.

6. The magnetically oriented steel fiber 3D printing concrete quick-release sliding form nozzle supporting manual feeding according to claim 2, characterized in that: A hollow plate is provided on the top of the hopper (307) and is communicated with the interior of the hopper (307) to form a recovery trough; the steel cylinder (309) transported against gravity is fixed by the hollow plate and its supporting auxiliary plate inside the hopper (307).

7. The magnetically oriented steel fiber 3D printing concrete quick-release sliding form nozzle supporting manual feeding according to claim 2, characterized in that: The magnetic assembly in the magnetic orientation module includes a magnet support (401), a first annular permanent magnet (402) and a second annular permanent magnet (403); the magnet support (401) is sleeved on the outer wall of the anti-gravity conveying steel cylinder (309); the first annular permanent magnet (402) is installed in an annular groove on the lower end face of the magnet support (401); the second annular permanent magnet (403) is installed in an annular groove on the upper end face of the nozzle (404); the two permanent magnets are axially magnetized and the end faces have opposite magnetic poles; the nozzle (404) is adsorbed on the magnet support (401) by magnetic force.

8. The magnetically oriented steel fiber 3D printing concrete quick-release sliding form nozzle supporting manual feeding according to claim 6, characterized in that: The sliding template (601) is a curved plate, the surface area of ​​which is larger than the diameter of the nozzle and does not block the recovery tank.

9. The magnetically oriented steel fiber 3D printing concrete quick-release sliding form nozzle supporting manual feeding according to claim 1, characterized in that: The sliding template (601) is sleeved on the outer wall of the nozzle (404) outlet through a connecting ring. The upper end surface and inner wall of the connecting ring are respectively bonded to the inner surface of the sliding template (601) and the outer wall of the nozzle. A through hole matching the nozzle is provided in the center of the sliding template (601).

10. A printing method for a magnetically oriented steel fiber 3D printing concrete quick-release sliding form nozzle supporting manual feeding according to claim 2, characterized in that: include: The mechanical arm drives the magnetically oriented steel fiber 3D printing concrete quick-release sliding form nozzle to move to the bottom of the lining to be repaired (1), and the steel fiber concrete material is manually fed from the feed port (308), and the steel fiber concrete material is deposited at the bottom of the inverted cone cavity below the hopper (307); The spiral extrusion rod (304) rotates under the drive of the power output structure, and its rotation speed is adjustable. The steel fiber concrete material is sent into the anti-gravity conveying steel cylinder (309) under the extrusion action of the spiral extrusion rod (304), and is transported to the nozzle (404) under the constraint of the anti-gravity conveying steel cylinder (309); The steel fibers are subjected to the magnetic orientation effect of the magnetic assembly at the nozzle (404) and are arranged along the axis close to the nozzle (404), thereby preventing the steel fibers from crossing or even entangled with each other inside the nozzle (404); as the spiral extrusion rod (304) rotates, concrete mixed with the magnetically oriented steel fibers is extruded from the nozzle (404) onto the lining (1) to be repaired; The sliding formwork (601) provides a continuous and smooth temporary support, and the extruded steel fiber concrete is constrained in the cavity formed between the sliding formwork (601) and the lining to be repaired (1), reducing the possibility of the 3D printed concrete peeling off and falling in the tunnel vault against the direction of gravity; the demoulding vibrator (603) vibrates to achieve demoulding between the sliding formwork module and the 3D printed concrete.

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