Construction device and method for rapid 3D printing of tunnel primary support

Abstract

The application discloses a kind of construction device and method of rapid 3D printing tunnel primary support, including turntable, big arm and tunnel contour alignment system, wherein: driven rod, it is set horizontally front and back, can reciprocate, its rear end is connected with spray head fixing frame;Tunnel contour alignment sleeve, coaxial sleeve is set on the rear end on driven rod, and can rotate on driven rod;Two hollow tubes extending towards distal end are spaced apart and set on the circumferential direction on the side wall of middle section, and spring is sleeved in each hollow tube;Tunnel contour alignment wheel, its roller is used to contact tunnel contour line at any time;Turntable, it is vertically arranged, and center axis is along front and back trend arrangement, can rotate around center axis;Big arm, for telescopic pipe body, its proximal end is connected with turntable along the diameter trend of turntable, and distal end is connected with tunnel contour alignment system.The construction device makes spray head keep equidistant and vertical with the surface of being sprayed in whole process, improves spray concrete quality, and reduces operating threshold and improves construction speed.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tunnel engineering construction, and particularly relates to a construction device and method for rapidly 3D printing a tunnel primary support. BACKGROUND

[0002] With the continuous development of the transportation industry, a large number of tunnels are built, and the application of the subsurface excavation method is very extensive in consideration of cost, stratum adaptability and the like. In the process of constructing a tunnel by the subsurface excavation method, in order to ensure safety, a primary support structure must be constructed in the first time after a certain length (0.5 m-2 m) is excavated, that is, an arch frame is erected, a steel mesh is laid, and concrete is sprayed to quickly form a support strength and limit the deformation of surrounding rock.

[0003] In order to ensure the quality of the primary support structure, according to the requirements of the specification, the concrete spraying operation needs to be carried out in blocks, the spraying nozzle is perpendicular to the sprayed surface, and according to the spraying speed and material characteristics, the spraying nozzle maintains a constant distance (0.5 m-1 m) from the sprayed surface to reduce rebound and form a primary support with uniform texture.

[0004] At present, the primary support of sprayed concrete is mainly constructed by manual handheld spraying and mechanical hand spraying. Among them, the handheld spraying has high labor intensity, high requirements for the skills and experience of workers, and quality fluctuations may occur due to replacement of workers. For high positions such as the tunnel vault, a frame needs to be erected or a excavation step needs to be reserved, and because the distance from the sprayed surface is too close, it also causes long-term harm to the health of workers. The mechanical hand spraying uses multiple mechanical arms and multiple joints to spray at a suitable spatial position through a console operation, which improves the working environment of workers and reduces the difficulty of high-altitude work. However, the operation difficulty is high, the equipment failure rate is high, and after the mechanical arm is positioned, the nozzle sprays in a swinging manner within a certain range, which is difficult to meet the requirements of "the spraying nozzle being perpendicular to the sprayed surface" and "the spraying nozzle maintaining a constant distance from the sprayed surface". If the spatial position of the mechanical arm is frequently changed, it is very time-consuming, and the work efficiency is less than that of manual handheld spraying. SUMMARY

[0005] The purpose of the present application is to provide a construction device and method for rapidly 3D printing a tunnel primary support, so that the nozzle maintains equal distance and perpendicularity with the sprayed surface throughout the process, improves the quality of sprayed concrete, reduces the operation threshold, improves the construction speed, and also has a good protective effect on the health of workers.

[0006] The present application adopts the following technical scheme: a construction device for rapidly 3D printing a tunnel primary support, comprising a turntable, a large arm and a tunnel contour alignment system, wherein:

[0007] The tunnel contour alignment system comprises a driven rod, a tunnel contour alignment sleeve and a tunnel contour alignment wheel, wherein:

[0008] The driven rod is a hexagonal prism, horizontally and front-to-back arranged, and can reciprocate front-to-back, with a nozzle fixing frame connected to the rear end thereof;

[0009] The tunnel contour alignment sleeve is a hollow cylinder with variable cross-section, with a thick middle section and thin ends, coaxially sleeved on the rear end of the driven rod to drive the driven rod to rotate; two hollow pipes extending towards the distal end are arranged on the side wall of the middle section in a circumferential direction, and each hollow pipe is sleeved with a spring in the same direction.

[0010] The tunnel contour alignment wheel is composed of a short rod and a roller, the short rod is coaxially sleeved in the hollow pipe, with the inner end connected to the spring and the outer end located outside the hollow pipe and connected to the roller, the roller is used to contact the tunnel contour line at all times, and the spring is used to provide power for the contact between the roller and the tunnel contour line.

[0011] The rotating disc is vertically arranged, with the central axis arranged in a front-to-back direction, and can rotate around the central axis;

[0012] The large arm is a telescopic pipe body, with the proximal end connected to the rotating disc along the diameter of the rotating disc and the distal end connected to the tunnel contour alignment system; the large arm can rotate with the rotating disc and drive the tunnel contour alignment system and the nozzle fixing frame to rotate around the inner wall of the tunnel.

[0013] Further, the distal end of the large arm is connected to the tunnel contour alignment system through a tunnel contour workbench, and the tunnel contour workbench comprises a double-triangle workbench, a roller shaft, a spoke wheel and a roller, wherein:

[0014] The double-triangle workbench is a double-layered triangle, with one vertex connected to the distal end of the large arm;

[0015] The roller is a hollow pipe body, horizontally and front-to-back arranged;

[0016] The roller shaft is a hollow pipe body, coaxially sleeved on the front end of the driven rod outside and the roller inside, with the front and rear ends penetrating through the roller, arranged on the outer side of the opposite side of the triangle workbench connected to the large arm, and penetrating through the steel plate base provided at the two ends of the triangle workbench and connected to the steel plate base through screw threads;

[0017] A plurality of spoke wheels are arranged on the roller shaft in an axial direction, with the outer side walls of the plurality of spoke wheels connected to the inner wall of the roller.

[0018] Further, a rubber roller is coaxially sleeved outside the roller, with the outer side wall of the rubber roller used to adhere to the tunnel contour line.

[0019] Further, a reciprocating system is sleeved in the roller shaft, comprising a reciprocating power rod and a linear motor, the rear end of the reciprocating power rod is sleeved in the roller shaft, and the front end of the driven rod is connected to the reciprocating power rod, the reciprocating power rod can reciprocate front-to-back along the roller shaft, and drives the driven rod to reciprocate front-to-back.

[0020] The linear motor is arranged on the reciprocating power rod to provide power for the reciprocating movement of the reciprocating power rod.

[0021] Further, the reciprocating power rod and the driven rod are connected through a rod shaft connecting sleeve, which comprises a sleeve bottom, a sleeve cover and a sleeve core, wherein the sleeve bottom is a hollow cylinder with one end closed and one end open; the outer diameter of the sleeve bottom matches the inner diameter of the drum shaft, and the sleeve bottom is coaxially arranged in the drum shaft; the closed end of the sleeve bottom is connected with the reciprocating power rod;

[0022] The sleeve cover is a cylindrical shell with an open front end and a semi-closed rear end; the front end of the sleeve cover is threadedly connected with the rear end of the sleeve bottom;

[0023] The sleeve core is two cylinders with different outer diameters connected in the axial direction, the thin end of the sleeve core is coaxially inserted through the rear end of the sleeve cover and connected with the front end of the driven rod; the sleeve core can rotate in the sleeve cover; the rear end of the sleeve core is located in the space surrounded by the sleeve bottom and the sleeve cover.

[0024] Further, the turntable comprises a fixed base disc, a main shaft and a rotatable cover disc, wherein:

[0025] The fixed base disc is vertically arranged, and the central axis is horizontally arranged from front to back; the main shaft is coaxially arranged in the center of the fixed base disc; a recessed annular gear is formed on the rear end side wall of the fixed base disc near the edge, and the fixed base disc can rotate around the main shaft;

[0026] The rotatable cover disc is a cylindrical disc body with an open front end and a closed rear end, which is coaxially buckled on the fixed base disc and passes through the main shaft at the rear end; an opening for the extension of the large arm is formed on the edge of the rotatable cover disc;

[0027] On the rotatable cover disc, and at the opposite end of the diameter where the opening is located, a special-shaped through hole is formed, and a counterweight lead block with the same shape as the special-shaped through hole is arranged in each special-shaped through hole.

[0028] Further, the large arm comprises a planetary gear and a telescopic large arm body, and the telescopic large arm body is composed of a plurality of rectangular hollow tubes with different widths nested together in sequence, wherein a circular hole is formed on the proximal end bottom plate of the rectangular hollow tube with the largest width, and the circular hole is sleeved on the rear end of the main shaft; a small motor and a speed reducer are arranged in the proximal end groove of the telescopic large arm body, and the speed reducer is located at the end of the proximal end and connected with the planetary gear, and the planetary gear is located on the annular gear and rotates around the annular gear.

[0029] Further, the turntable is arranged at the rear end of the chassis system, and the chassis system comprises a control console, a heavy support and a hydraulic leg; the control console and the heavy support are arranged front to back and at the rear end of the chassis, and the rear end of the heavy support is connected with the main shaft; the control console is connected with the linear motor and the small motor;

[0030] The hydraulic supporting legs are three, two of which are installed on the left and right sides of the bottom of the base plate and are located in the area where the rear heavy support is placed, and the other is sleeved on the rear end of the main shaft.

[0031] Further, the linear motor is arranged in the motor compartment, which is a shell structure and is sleeved on the reciprocating power rod, both ends of the motor compartment are buckled with motor compartment covers, and the motor compartment covers are provided with through holes for the reciprocating power rod to pass through.

[0032] The rod sleeve is connected to the motor compartment cover at the front end, the connection end of the rod sleeve to the motor compartment cover is open, and is in communication with the through hole, and the end away from the motor compartment cover is closed; the rod sleeve serves as a track for the reciprocating movement of the reciprocating power rod and a protective sleeve.

[0033] The application also discloses a construction method of the construction device for quickly 3D printing a tunnel primary support.

[0034] Step S1, positioning of the construction device:

[0035] Determine the tunnel center line, determine the projection line of the cross section of the constructed primary support structure on the ground, and retreat along the tunnel center line away from the excavation surface, the retreat distance satisfying the following conditions: after the extension of the large arm, the rubber roller and the tunnel contour alignment wheel are in contact with the completed primary support structure; the hydraulic supporting leg of the main shaft is located on the tunnel center line.

[0036] Step S2, determination of the construction area:

[0037] The device starts the small motor through the control console, rotates the large arm to the horizontal position, extends the telescopic large arm body, and until the rubber roller and the tunnel contour alignment wheel are in contact with the completed tunnel primary support, and the pressure feedback by the pressure sensor reaches the rated pressure P.

[0038] Through the control console, the linear motor is started, the reciprocating power rod is driven, the driving force is sequentially transmitted to the driving shaft rod connecting sleeve, the driven rod and the nozzle fixing frame, the nozzles on the nozzle fixing frame are aligned with the position of the contour edge on the other side of the axis of the completed tunnel primary support, and the linear motor is closed, and the control console records the position as A; the linear motor is driven again, the nozzles in the nozzle fixing frame are aligned with the position of the contour edge on the other side of the tunnel primary support to be constructed, and the linear motor is closed, and the control console records the position as B; the starting points of the construction reciprocating movement are set as A and B.

[0039] Through the control console, the small motor is started, the telescopic large arm body is driven to rotate from one side wall of the tunnel, and until the tunnel contour workbench runs to the bottom of the other side wall of the tunnel, which is the starting position of the large arm.

[0040] Step S3, 3D printing construction:

[0041] Step S3-1, communicate the concrete, start the linear motor through the control console, make the spray head on the spray head fixed frame reciprocate along AB two points to spray the concrete;

[0042] After the tunnel primary support in the spray head coverage area reaches the design thickness, the linear motor is turned off through the control console, and the concrete is cut off;

[0043] Step S3-2, start the small motor, drive the telescopic large arm body to rotate, and the telescopic large arm body automatically telescopes, keep the tunnel contour workbench closely attached to the completed tunnel primary support, and the tunnel contour alignment system twists the driven rod and the spray head fixed frame 7, so that the spray head is perpendicular to the sprayed surface;

[0044] Step S3-3, repeat step S3-1 and step S3-2 until the construction of all primary supports in the current cycle is completed.

[0045] The beneficial effects of the application are: 1. By setting the tunnel contour alignment system, the spray head is always kept equidistant and perpendicular to the sprayed surface during the whole concrete spraying operation, improving the quality of the sprayed concrete. 2. The large arm has telescopic function and can rotate with the turntable, keeping the tunnel contour workbench closely attached to the tunnel contour, and setting the specified pressure to ensure the consistency of the attachment during the whole spraying process. 3. During the spraying process, the personnel only need to control one parameter, i.e. the rotation of the large arm, so the spraying technical requirements for the construction personnel are low, and the dependence on the construction personnel is reduced. 4. The reciprocating power rod and the driven rod cooperate to drive the spray head to reciprocate in front of and behind the tunnel operation surface, and under the drive of the turntable, the spray head rotates around the tunnel operation surface, realizing the full-face multi-spray head operation, and the whole process is uninterrupted and adjusted, and the construction speed is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 It is a schematic view of the main structure of a rapid 3D printing tunnel primary support construction device;

[0047] Figure 2 It is a schematic view of the tunnel contour alignment system of a rapid 3D printing tunnel primary support construction device;

[0048] Figure 3 It is a schematic view of the tunnel contour workbench of a rapid 3D printing tunnel primary support construction device;

[0049] Figure 4 It is a schematic view of the large arm of a rapid 3D printing tunnel primary support construction device;

[0050] Figure 5 It is a schematic view of the turntable of a rapid 3D printing tunnel primary support construction device Figure 1 ;

[0051] Figure 6It is a construction device turntable schematic diagram of a kind of fast 3D printing tunnel primary support Figure 2 ;

[0052] Figure 7 It is a construction device reciprocating system schematic diagram of a kind of fast 3D printing tunnel primary support;

[0053] Figure 8 It is a fixed frame amplification schematic diagram of a kind of fast 3D printing tunnel primary support construction device;

[0054] Figure 9 It is a chassis system schematic diagram of a kind of fast 3D printing tunnel primary support construction device;

[0055] Figure 10 It is the working schematic of a kind of fast 3D printing tunnel primary support construction device tunnel contour alignment system Figure 1 ;

[0056] Figure 11 It is the working schematic of a kind of fast 3D printing tunnel primary support construction device tunnel contour alignment system Figure 2 ;

[0057] Figure 12 It is the working schematic of a kind of fast 3D printing tunnel primary support construction device tunnel contour alignment system Figure 3 ;

[0058] Figure 13 It is the schematic diagram of a kind of fast 3D printing tunnel primary support construction device rod shaft connecting sleeve;

[0059] Figure 14 It is the construction drawing of a kind of fast 3D printing tunnel primary support construction device;

[0060] Figure 15 It is the construction process diagram of a kind of fast 3D printing tunnel primary support construction device;

[0061] Wherein: 1. chassis system;11. bottom plate;12. wheel;13. control console;14. heavy support;15. hydraulic outrigger;

[0062] 2. Turntable;21. fixed base disk;22. main shaft;23. rotatable cover disk;24. counterweight lead block;

[0063] 3. Large arm;31. planetary gear;32. speed reducer;33. small motor;34. pressure sensor;35. hydraulic telescopic oil cylinder;36. telescopic large arm body;

[0064] 4. Tunnel contour workbench;41. double tripod workbench;42. roller shaft;43. spoke wheel;44. roller;45. rubber roller;46. side cover plate;

[0065] 5. Reciprocating system; 51. Motor compartment; 52. Linear motor; 53. Motor compartment cover; 54. Rod sleeve; 55. Reciprocating power rod;

[0066] 6. Tunnel profile alignment system; 61. Follower rod; 62. Tunnel profile alignment sleeve; 63. Light tripod; 64. Spring; 65. Tunnel profile alignment wheel; 66. Auxiliary bracket;

[0067] 7. Nozzle fixing bracket; 71. Mountain bracket; 72. Pipe clamp;

[0068] 8. Rod-shaft connecting sleeve; 81. Sleeve bottom; 82. Sleeve cover; 83. Sleeve core. DETAILED DESCRIPTION

[0069] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0070] The present invention provides a construction device for rapid 3D printing of tunnel primary support, such as Figure 1 As shown, it includes: chassis system 1, turntable 2, boom 3, tunnel contour workbench 4, reciprocating system 5, tunnel contour alignment system 6, nozzle fixing frame 7 and rod shaft connecting sleeve 8, wherein:

[0071] like Figure 2 As shown, the tunnel profile alignment system 6 includes: a driven rod 61, a tunnel profile alignment sleeve 62, a light tripod 63, a spring 64, a tunnel profile alignment wheel 65 and an auxiliary bracket 66, wherein:

[0072] The auxiliary bracket 66 is a long steel plate with a Z-shaped cross section. One end of the vertical plate is fixed to the rear end steel plate of the double tripod workbench 41 by bolts. The other end of the vertical plate has a hole through which a steel pipe is welded. The steel pipe has the same size as the roller shaft 42.

[0073] The driven rod 61 is a steel rod with a regular hexagonal cross section, i.e., a hexagonal prism, which is coaxially connected to the rear end of the reciprocating power rod 55 through the rod-shaft connecting sleeve 8 and performs synchronous reciprocating motion therewith;

[0074] The tunnel profile alignment sleeve 62 is a three-section hollow cylinder with a variable cross-section, thicker in the middle and thinner at both ends. The outer diameters of the two end cylinders match the inner diameter of the roller shaft 42 and are coaxially mounted on the driven rod 61 to drive the driven rod 61 to rotate. A lightweight tripod 63 is welded to the middle section of the tunnel profile alignment sleeve 62 and along the same cross-section. The lightweight tripod 63 comprises two hollow steel pipes welded to the middle section of the tunnel profile alignment sleeve 62, with the extension lines of the two hollow steel pipes perpendicular to each other, and a third rod connected between the two hollow steel pipes. Each hollow steel pipe has a built-in spring 64 aligned with its direction, and a tunnel profile alignment wheel 65 is provided on the open end of the spring 64 near the hollow steel pipe.

[0075] Tunnel contour alignment wheel 65 is composed of a short rod and a small roller, the outer dimension of the short rod matches the inner diameter of the hollow steel pipe, it is coaxially inserted into the hollow steel pipe and connected with the spring 64 inside the pipe, the short rod can freely stretch in the hollow steel pipe, under the action of the spring 64, the roller is always in contact with the tunnel contour line; as shown in Figure 10 、 11 and 12.

[0076] After installing the auxiliary support 66, the tunnel contour alignment sleeve 62 is clamped between the auxiliary support 66 and the roller shaft 42 and can freely rotate.

[0077] As shown in Figure 3 , the tunnel contour workbench 4 includes a double tripod workbench 41, a roller shaft 42, a spoke wheel 43, a roller 44, a rubber roller 45 and a side cover plate 46, wherein:

[0078] The double tripod workbench 41 is a steel integral welded structure with a double-layer structure, each layer is an isosceles triangle, and the two isosceles intersecting top ends are provided with a connecting sleeve connected with the telescopic large arm body 36; a steel plate base perpendicular to the third side and extending towards the distal end is connected at both ends of the third side, threaded holes are formed on each steel plate base, and two insertion holes are on the same straight line; a roller shaft 42 parallel to the third side is arranged on the outer side of the third side, the roller shaft 42 is a hollow steel pipe with open ends, the two ends are inserted into the threaded holes and are threadedly connected with the threaded holes, and can rotate in the threaded holes.

[0079] The spoke wheel 43 is at least three, coaxially sleeved on the roller shaft 42, and spaced along the length direction of the roller shaft 42, and can freely rotate around the roller shaft 42 to provide sufficient support force for the roller 44; the roller 44 is a steel thin-walled cylinder, coaxially sleeved outside the plurality of spoke wheels 43 and welded with each spoke wheel 43 as a whole;

[0080] The rubber roller 45 is made of hard and wear-resistant rubber material, the rubber thickness is not less than 2 cm, matched with the roller 44, coaxially sleeved outside the roller 44, to avoid high-pressure hard contact with the initial support of the tunnel (set pressure P) and damage the initial support; the side cover plate 46 is an annular plate matched with the roller shaft 42 and the roller 44, buckled at both ends of the roller 44, used to close the roller 44 to avoid dust intrusion during the shotcreting operation and affect the operation of the component.

[0081] As shown in Figure 7 , the reciprocating system 5 includes a motor compartment 51, a linear motor 52, a motor compartment cover 53, a rod sleeve 54 and a reciprocating power rod 55, wherein:

[0082] The reciprocating power rod 55 is a rectangular section stainless steel rod body, the rear end of which is connected with the front end of the drum shaft 42 in the axial direction, a linear motor 52 is sleeved on the reciprocating power rod 55, the linear motor 52 is covered with a motor bin 51, a motor bin cover 53 is buckled at the front end of the motor bin 51, and the motor bin cover 53 is sleeved on the reciprocating power rod 55, an axial rod sleeve 54 is connected with the reciprocating power rod 55 in the same straight line through bolt connection on the outer wall of the front end of the motor bin cover 53; the openings of the motor bin 51 and the motor bin cover 53 match the size of the reciprocating power rod 55.

[0083] The rod sleeve 54 is made of PVC plastic material, the outer section is a rounded rectangle, the inner section is a hollow rectangle, the inner section size matches the reciprocating power rod 55, and the rod sleeve 54 serves as a track and protective sleeve for the reciprocating motion of the reciprocating power rod 55, the connecting end opening of the rod sleeve 54 is connected with the motor bin cover 53, and the distal end is closed;

[0084] The linear motor 52 generates a moving magnetic field after being connected to alternating current, drives the reciprocating power rod 55 to move linearly through the Faraday effect, and can change the moving direction and moving distance of the magnetic field through a control circuit, so as to realize the reciprocating motion of the reciprocating power rod 55 and set the start and stop positions of the reciprocating motion, and the working principle has been maturely applied to products such as electric control machine tool cutter head motion and printer nozzle motion.

[0085] As shown in Figure 13 The rod shaft connecting sleeve 8 comprises a sleeve bottom 81, a sleeve cover 82 and a sleeve core 83, wherein:

[0086] The sleeve bottom 81 is a steel hollow cylinder, the outer diameter of which matches the inner diameter of the drum shaft 42, and the sleeve bottom 81 is coaxially sleeved in the drum shaft 42; one end of the sleeve bottom 81 is closed, and the other end is open, an inner thread is arranged on the inner wall of the open end, and two steel plates are arranged on the outer side of the closed end for clamping the reciprocating power rod 55 and fixedly connecting the reciprocating power rod 55 through bolts;

[0087] The sleeve cover 82 is a steel cylindrical shell, the outer diameter of which matches the inner diameter of the drum shaft 42, and the sleeve cover 82 is coaxially sleeved in the drum shaft 42; one end of the sleeve cover 82 is open, and the other end is semi-closed, an outer thread is arranged on the open end, and the semi-closed end is provided with a circular hole structure in the center;

[0088] The sleeve core 83 is made of steel, and the sleeve core 83 is a two-section cylinder with different outer diameters in the axial direction, the outer diameter of the thick end matches the inner diameter of the sleeve cover 82, and the outer diameter of the thin end matches the inner diameter of the opening of the sleeve cover 82; after the sleeve core 83 is inserted into the sleeve cover 82, the sleeve core 83 can rotate freely, the thin end of the sleeve core 83 penetrates out of the sleeve cover 82 and is inserted into the circular hole at the end of the driven rod 61, and the sleeve core 83 is connected with the driven rod 61 as a whole through a pin rod;

[0089] The main function of the rod shaft connecting sleeve 8 is to transmit the reciprocating motion of the reciprocating power rod 55 to the driven rod 61, and the driven rod 61 can be additionally axially freely rotated, at the same time, the outer diameter of the rod shaft connecting sleeve 8 matches the inner diameter of the drum shaft, which is equivalent to a piston device, which can help to position the end axis of the reciprocating power rod 55 and the driven rod 61, and further isolate the dust that may spread from the inside of the drum shaft 42 on the side of the driven rod 61, thereby enhancing the sealing and dustproof performance of the reciprocating power rod 55 in the moving bin.

[0090] As shown in Figure 9 , the chassis system 1 comprises a base plate 11, wheels 12, a control console 13, a heavy support 14 and hydraulic legs 15, wherein:

[0091] The base plate 11 is a flat steel plate, and the wheels 12 are arranged on both sides of the base plate 11. The radius of the wheels 12 is greater than 0.6 m, so that the surface of the base plate 11 is higher than 0.8 m from the ground, thereby providing sufficient working space for the rotating disc 2 at the tail end.

[0092] The control console 13 is fixed to the base plate 11. The heavy support 14 is a block-shaped body located at the rear end of the base plate 11.

[0093] The hydraulic legs 15 are three in total, two of which are installed on the lower wall of the base plate 11 and located in the area where the heavy support 14 is placed, and the other one is sleeved on the main shaft 22 to provide sufficient supporting force.

[0094] As shown in Figure 5 and 6 , the rotating disc 2 comprises a fixed base disc 21, a main shaft 22, a rotatable cover disc 23 and a lead weight 24, wherein:

[0095] The fixed base disc 21 is a steel disc with a diameter of 2 m and a thickness of not less than 2 cm. It is vertically arranged, and one side wall thereof faces the heavy support 14 and is fixed to the tail end surface of the heavy support 14 by welding or mechanical connection. The fixed base disc 21 is provided with a circular hole in the center, and the main shaft 22 is coaxially arranged in the circular hole. An annular tooth recessed with the center as the center is formed on the other side wall thereof as a movement track of the planetary gear 31. The annular tooth is located near the distal edge of the fixed base disc 21. The main shaft 22 is a stainless steel cylindrical shaft which passes through the circular hole in the center of the fixed base disc 21 and is inserted into the heavy support 14 to improve the stability thereof.

[0096] The rotatable cover disc 23 is a steel cylindrical cover disc which is provided with an axially through circular hole in the center and matches with the main shaft 22 to be sleeved on the main shaft 22.

[0097] As shown in Figure 4 , the large arm 3 comprises a planetary gear 31, a speed reducer 32, a small motor 33, a pressure sensor 34, a hydraulic telescopic oil cylinder 35 and a telescopic large arm body 36, as shown in Figure 5 , wherein:

[0098] The telescopic arm body 36 is composed of multiple sections of rectangular hollow tubes with different widths, and the multiple sections of rectangular hollow tubes are nested together in sequence. A circular hole is formed in the proximal end plate of the rectangular hollow tube with the largest width, and the hole is used to pass through the main shaft 22. One end of the telescopic arm body 36 located in the region above the main shaft 22 is the distal end, which extends upward and beyond the edge of the fixed base plate 21. The other end of the telescopic arm body 36 located in the region below the main shaft 22 is the proximal end. A small motor 33 and a speed reducer 32 are arranged in the proximal end slot of the telescopic arm body 36. The speed reducer 32 is located at the end of the proximal end of the telescopic arm body 36. The output shaft of the speed reducer 32 is directed towards the end of the telescopic arm body 36 and is connected to the planetary gear 31, which is located on the annular gear. The small motor 33 is connected to the control console 13, and the rotation direction of the small motor 33 is controlled by the control console 13. Through the speed reduction of the speed reducer 32, the rotation speed of the planetary gear 31 is reduced, and the torque is increased. The planetary gear 31 rotates around the annular gear, thereby rotating the telescopic arm body 36 around the main shaft 22. In the region above the main shaft 22, the pressure sensor 34 and the hydraulic telescopic cylinder 35 are arranged in the slot of the telescopic arm body 36 from bottom to top. The lower end of the hydraulic telescopic cylinder 35 is connected to the pressure sensor 34, and the upper end is connected to the upper end of the uppermost rectangular hollow tube. The hydraulic telescopic cylinder 35 pushes the uppermost rectangular hollow tube to extend the telescopic arm body 36, pushes the tunnel contour workbench 4 to tightly fit the tunnel contour, and generates pressure, which is monitored by the pressure sensor 34. Through the control program built in the control console 13, the set pressure value P is set, and the automatic telescoping is realized during the rotation of the arm 3, thereby maintaining the close state of the tunnel contour workbench 4 and the tunnel contour.

[0099] Since the device is arranged on the tunnel floor, and the tunnel contour shape is different, the distance between the rotating disc 2 and the tunnel contour line at different positions is different, and the required arm length is different. During the rotation of the arm 3, when the length of the arm 3 gradually becomes insufficient, the tunnel contour workbench 4 and the tunnel contour tend to move away, the monitoring data of the pressure sensor 34 decreases, and the feedback is sent to the control console 13. The control program is started, hydraulic oil is injected into the hydraulic telescopic cylinder 35, the telescopic arm body 36 is extended, the pressure P is restored, and the oil injection is stopped. Similarly, when the length of the arm 3 gradually becomes excessive, the tunnel contour workbench 4 and the tunnel contour tend to be further pressed, the monitoring data of the pressure sensor 34 increases, the feedback is sent to the control console 13, the control program is started, the hydraulic oil in the hydraulic telescopic cylinder 35 is pumped out, the telescopic arm body 36 is shortened, the pressure P is restored, and the oil pumping is stopped.

[0100] The rated pressure P value is: when the boom 3 is vertical, it is twice the total weight of the boom 3, the tunnel contour workbench 4, the reciprocating system 5, the tunnel contour alignment system 6 and the nozzle fixing frame 7. Therefore, during the entire operation of the equipment, the tunnel contour workbench 4 can overcome the weight of the equipment while offsetting the recoil force of the nozzle when spraying concrete, so that the tunnel contour workbench 4 always fits closely to the tunnel contour.

[0101] The nozzle fixing frame 7 includes: a mountain frame 71 and a pipe hoop 72, such as Figure 8 As shown, where:

[0102] The crossbar 71 is made of hollow steel. The open end of the crossbar 71 is located at the rear end, and its front end is fixedly connected to the rear end of the driven rod 61. Specifically, a regular hexagonal hoop is provided at the rear end, which is fixedly connected to the driven rod 61 via a pin. A pipe hoop 72 is welded to the end of each of the three short rods. Each pipe hoop 72 is used to clamp the concrete spraying head. Among them, the crossbar 71 can be provided with three short rods. On the one hand, the amount of concrete sprayed per unit time can be increased, speeding up the construction speed. On the other hand, the bifurcation of the edge can expand the concrete spraying range, covering the possible spraying blind spots at the starting and ending points of the tunnel contour workbench 4.

[0103] The chassis system 1 is a base that serves as a load-bearing structure and facilitates the movement and operation of the construction device for rapid 3D printing of tunnel primary supports. After the chassis system 1 is fixed in a set position, the turntable 2 provides rotational power for the boom 3. At the same time, the boom 3 has an automatic telescopic function. The two work together to ensure that the tunnel contour workbench 4 connected to the end of the boom 3 is tightly attached to the primary support structure of the tunnel contour and moves along the tunnel contour line within the same tunnel section.

[0104] In the above process, the reciprocating system 5 provides axial reciprocating power, and the tunnel profile alignment system 6 rotates along the reciprocating axis. The two work together to make the spraying machine nozzle on the nozzle fixing frame 7 continuously reciprocate, and the nozzle is always perpendicular to the sprayed surface.

[0105] The present invention also discloses a construction method of a rapid 3D printing tunnel primary support construction device, such as Figure 14 and 15 As shown, the construction method is as follows:

[0106] Step S1: Positioning of construction device:

[0107] Determine the tunnel centerline and the projection line of the cross section of the constructed primary support structure on the ground. At the intersection of these two lines, retreat 0.5m or more along the tunnel centerline away from the excavation face. The retreat distance satisfies the following requirements: after the boom 3 is extended, the rubber roller 45 and the tunnel contour alignment wheel 65 are both in contact with the completed primary support structure; and the hydraulic support legs 15 of the main shaft 22 are located on the tunnel centerline.

[0108] Further, the height of the three hydraulic legs 15 is adjusted by using a leveling rod, so that the base plate 11 is leveled, and thus the turntable 2 is parallel to the tunnel cross section, that is, the large arm 3 is always in the same tunnel cross section when it rotates.

[0109] Step S2, construction area determination:

[0110] The device starts the small motor 33 through the console 13 to rotate the large arm 3 to the horizontal position, extends the telescopic large arm body 36 until the rubber roller 45 and the contour alignment wheel 65 are in close contact with the completed tunnel primary support, and the pressure sensor 34 feedbacks the pressure reaching the rated pressure P;

[0111] The linear motor 52 is turned on through the console 13 to drive the reciprocating power rod 55, and the driving force is sequentially transmitted to the driven shaft rod connecting sleeve 8, the driven rod 61 and the nozzle fixing frame 7, so that the nozzles on the nozzle fixing frame 7 are aligned with the position of the contour edge on the side of the completed tunnel primary support in the axial direction, and the linear motor 52 is turned off. The console 13 records the position at this time as A; the linear motor 52 is driven again to make the nozzles in the nozzle fixing frame 7 align with the position of the contour edge on the other side of the tunnel primary support to be constructed, and the linear motor 52 is turned off. The console 13 records the position at this time as B; and the starting points of the construction reciprocating motion are set as A and B.

[0112] The small motor 33 is turned on through the console 13 to drive the telescopic large arm body 36 to rotate from one side wall of the tunnel until the tunnel contour workbench 4 runs to the bottom of the other side wall of the tunnel, which is the starting position of the large arm 36.

[0113] After the concrete material to be sprayed is brought in, the pipelines of the three concrete spraying machines are installed and connected, and the three nozzles of the spraying machines are installed on the nozzle fixing frame 7.

[0114] Step S3, 3D printing construction:

[0115] Step S3-1, connecting concrete, the linear motor 52 is started through the console 13 to start the concrete spraying machine, so that the nozzles on the nozzle fixing frame 7 make reciprocating motion forward and backward along the two points A and B to spray concrete;

[0116] After the tunnel primary support in the nozzle coverage area reaches the designed thickness, the linear motor 52 is turned off through the console 13 to cut off the concrete;

[0117] Step S3-2, the small motor 33 is turned on to drive the telescopic large arm body 36 to rotate, and the telescopic large arm body 36 automatically extends and retracts to keep the tunnel contour workbench 4 closely in contact with the completed tunnel primary support, and the tunnel contour alignment system 6 twists the driven rod 61 and the nozzle fixing frame 7 to make the nozzles perpendicular to the sprayed surface;

[0118] Step S3-3, repeat step S3-1 and step S3-2 until the construction of all primary supports of this cycle is completed.

Claims

1. A construction device for rapid 3D printing of a tunnel primary support, characterized in that, The device comprises a rotating disc (2), a large arm (3) and a tunnel contour alignment system (6), wherein: The tunnel contour alignment system (6) comprises a driven rod (61), a tunnel contour alignment sleeve (62) and a tunnel contour alignment wheel (65), wherein: The driven rod (61) is a hexagonal prism, horizontally arranged from front to back, and can move back and forth, with a nozzle fixing frame (7) connected to the rear end; The tunnel contour alignment sleeve (62) is a hollow cylinder with variable cross-section, with a thick middle section and thin ends, coaxially sleeved on the rear end of the driven rod (61) to drive the driven rod (61) to rotate; two hollow pipes extending towards the distal end are arranged on the side wall of the middle section, with a spring (64) coaxially sleeved in each hollow pipe; and the extension lines of the two hollow steel pipes are perpendicular; The tunnel contour alignment wheel (65) is composed of a short rod and a roller, the short rod is coaxially sleeved in the hollow pipe, the inner end is connected with the spring (64), and the outer end is located outside the hollow pipe and connected with the roller, the roller is used to contact the tunnel contour line at all times, and the spring (64) is used to provide the power for the contact between the roller and the tunnel contour line; The rotating disc (2) is vertically arranged, with the central axis arranged along the front-to-back direction, and can rotate around the central axis; The large arm (3) is a telescopic pipe body, with the proximal end connected with the rotating disc (2) along the diameter of the rotating disc (2), and the distal end connected with the tunnel contour alignment system (6); it can rotate with the rotating disc (2) and drive the tunnel contour alignment system (6) and the nozzle fixing frame (7) to rotate around the inner wall of the tunnel.

2. The device for quickly constructing a 3D printed tunnel primary support according to claim 1, wherein: The distal end of the large arm (3) is connected with the tunnel contour alignment system (6) through a tunnel contour workbench (4), and the tunnel contour workbench (4) comprises a double tripod workbench (41), a roller shaft (42), a spoke wheel (43) and a roller (44), wherein: The double tripod workbench (41) is a double-layered triangular shape, with one vertex connected with the distal end of the large arm (3); The roller (44) is a hollow pipe body, horizontally arranged from front to back; The roller shaft (42) is a hollow pipe body, coaxially sleeved on the front end outside the driven rod (61) and the roller (44), with the front and rear ends penetrating through the roller (44) and arranged on the outer side of the opposite side of the double tripod workbench (41) connected with the large arm (3), and penetrating through the steel plate bases arranged at the two ends of the double tripod workbench (41) and threadedly connected with the steel plate bases; A plurality of spoke wheels (43) are arranged on the roller shaft (42) and spaced along the axial direction, and the outer side walls of the plurality of spoke wheels (43) are connected with the inner wall of the roller (44).

3. The construction device for rapid 3D printing of tunnel primary support according to claim 1 or 2, characterized in that, A rubber roller (45) is coaxially sleeved outside the roller (44), and the outer side wall of the rubber roller (45) is used to adhere to the tunnel contour line.

4. The construction device for rapid 3D printing of tunnel primary support according to claim 3, characterized in that, A reciprocating system (5) is sleeved in the drum shaft (42), the reciprocating system (5) comprises a reciprocating power rod (55) and a linear motor (52), the rear end of the reciprocating power rod (55) is sleeved in the drum shaft (42), and the front end of the driven rod (61) is connected with the reciprocating power rod (55); the reciprocating power rod (55) can reciprocate along the drum shaft (42) and drive the driven rod (61) to reciprocate; The linear motor (52) is arranged on the reciprocating power rod (55) and is used for providing power for the reciprocating motion of the reciprocating power rod (55).

5. The construction device for rapid 3D printing of tunnel primary support according to claim 4, characterized in that, The reciprocating power rod (55) and the driven rod (61) are connected through a rod shaft connecting sleeve (8), the rod shaft connecting sleeve (8) comprises a sleeve bottom (81), a sleeve cover (82) and a sleeve core (83), wherein the sleeve bottom (81) is a hollow cylinder, one end of which is closed and the other end is open; the outer diameter of the sleeve bottom (81) matches the inner diameter of the drum shaft (42), and the sleeve bottom (81) is coaxially sleeved in the drum shaft (42); the closed end of the sleeve bottom (81) is connected with the reciprocating power rod (55); The sleeve cover (82) is a cylindrical shell, the front end of the sleeve cover (82) is open, and the rear end of the sleeve cover (82) is semi-closed; the front end of the sleeve cover (82) is threadedly connected with the rear end of the sleeve bottom (81); The sleeve core (83) is two cylinders with different outer diameters connected in the axial direction, the thin end of the sleeve core (83) is coaxially connected with the rear end of the sleeve cover (82) and connected with the front end of the driven rod (61); the sleeve core (83) can rotate in the sleeve cover (82); the rear end of the sleeve core (83) is located in the space surrounded by the sleeve bottom (81) and the sleeve cover (82).

6. The construction device for rapid 3D printing of tunnel primary support according to claim 5, characterized in that, The rotating disc (2) comprises a fixed base disc (21), a main shaft (22) and a rotatable cover disc (23), wherein: The fixed base disc (21) is vertically arranged, and the central axis is horizontally arranged along the front and back directions; the main shaft (22) is coaxially arranged in the center of the fixed base disc (21); a recessed annular gear is arranged on the rear end side wall of the fixed base disc (21) and close to the edge; the fixed base disc (21) can rotate around the main shaft (22); The rotatable cover disc (23) is a columnar disc body, the front end of the rotatable cover disc (23) is open, and the rear end of the rotatable cover disc (23) is closed; the rotatable cover disc (23) is coaxially buckled on the fixed base disc (21) and passes through the main shaft (22); an opening is arranged on the edge shell of the rotatable cover disc (23) for the large arm (3) to extend out; A special-shaped through hole is arranged on the rotatable cover disc (23) and located at the opposite end of the diameter of the opening; a counterweight lead block (24) with the same shape is arranged in each special-shaped through hole.

7. The construction device for rapid 3D printing of tunnel primary support according to claim 6, characterized in that, The large arm (3) comprises a planetary gear (31) and a telescopic large arm body (36) which is composed of a plurality of rectangular hollow tubes with different widths nested together in sequence, wherein a circular hole is formed on the proximal end base of the rectangular hollow tube with the largest width, and the circular hole is sleeved on the rear end of the main shaft (22); a small motor (33) and a speed reducer (32) are arranged in the proximal end groove of the telescopic large arm body (36) and connected, and the speed reducer (32) is located at the distal end of the proximal end and connected with the planetary gear (31), and the planetary gear (31) is located on the annular gear and rotates around the annular gear.

8. The construction device for rapid 3D printing of tunnel primary support according to claim 7, characterized in that, The turntable (2) is arranged at the rear end of the chassis system (1), the chassis system (1) comprises a console (13), a heavy support (14) and a hydraulic leg (15), the console (13) and the heavy support (14) are arranged in front of and behind each other and arranged at the rear end of the bottom plate (11), and the rear end of the heavy support (14) is connected with the main shaft (22); the console (13) is connected with the linear motor (52) and the small motor (33); The hydraulic leg (15) is three, two of which are arranged on the left and right sides of the bottom of the bottom plate (11) and located in the area where the rear heavy support (14) is placed; the other is sleeved on the rear end of the main shaft (22).

9. The construction device for rapid 3D printing of tunnel primary support according to claim 8, characterized in that, The linear motor (52) is arranged in the motor compartment (51), the motor compartment (51) is a shell structure, is sleeved on the reciprocating power rod (55), and the motor compartment cover (53) is buckled on the front and rear ends of the reciprocating power rod (55), and the motor compartment cover (53) is provided with a through hole for the reciprocating power rod (55) to pass through; The motor compartment cover (53) is connected with the rod sleeve (54), the connection end of the rod sleeve (54) with the motor compartment cover (53) is open, and communicates with the through hole, and the end away from the motor compartment cover (53) is closed; the rod sleeve (54) is used as the track and protection sleeve of the reciprocating motion of the reciprocating power rod (55).

10. The construction method of a construction device for rapid 3D printing of a tunnel primary support according to any one of claims 1-9, characterized in that, The construction method is as follows: Step S1, positioning of the construction device: Determine the tunnel center line, determine the projection line of the cross section of the constructed primary support structure on the ground, retreat along the tunnel center line away from the excavation surface at the intersection of the two lines, and the retreat distance satisfies the following conditions: after the large arm (3) is elongated, the rubber roller (45) and the tunnel contour alignment wheel (65) are all in contact with the completed primary support structure; the hydraulic leg (15) of the main shaft (22) is located on the tunnel center line; Step S2, construction area determination: The device starts the small motor (33) through the console (13), rotates the large arm (3) to the horizontal position, elongates the telescopic large arm body (36), and until the rubber roller 45 and the tunnel contour alignment wheel (65) are in contact with the completed tunnel primary support, and the pressure feedback by the pressure sensor (34) reaches the quota pressure P; Through the console (13), the linear motor (52) is started, the reciprocating power rod (55) is driven, and the driving force is sequentially transmitted to the driven shaft rod connecting sleeve (8), the driven rod (61) and the nozzle fixed frame (7), so that the nozzles on the nozzle fixed frame (7) are aligned with the position of the profile edge on one side of the axial direction of the completed tunnel primary support, and the linear motor (52) is closed. The console (13) records the position at this time as A; the linear motor (52) is driven again, so that the nozzles in the nozzle fixed frame (7) are aligned with the position of the profile edge on the other side of the tunnel primary support to be constructed, and the linear motor (52) is closed. The console (13) records the position at this time as B; the starting point of the construction reciprocating motion is set as A and B; Through the console (13), the small motor (33) is started, and the telescopic large arm body (36) is rotated from one side wall of the tunnel until the tunnel profile workbench (4) runs to the bottom of the other side wall of the tunnel, which is the starting position of the large arm (36); Step S3, 3D printing construction: Step S3-1, connect the concrete, start the linear motor (52) through the console (13), and make the nozzles on the nozzle fixed frame (7) reciprocate along AB two points to spray concrete; After the tunnel primary support covered by the nozzles reaches the designed thickness, the linear motor (52) is closed through the console (13), and the concrete is cut off; Step S3-2, start the small motor (33) to drive the telescopic large arm body (36) to rotate, and the telescopic large arm body (36) automatically telescopes to keep the tunnel profile workbench (4) closely attached to the completed tunnel primary support, while the tunnel profile alignment system (6) twists the driven rod (61) and the nozzle fixed frame 7 to make the nozzles perpendicular to the sprayed surface; Step S3-3, repeat steps S3-1 and S3-2 until the construction of all primary supports in this cycle is completed.

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