阅读说明：本技术 用于3d打印相似物理模型的复合型喷嘴及其工作方法 (Composite nozzle for 3D printing of similar physical model and working method thereof ) 是由 冯晓巍 薛飞 杜高明 王德华 于 2021-06-28 设计创作，主要内容包括：一种用于3D打印相似物理模型的复合型喷嘴及其工作方法,喷嘴：锚杆植入模块和挤出喷嘴模块分别设置在衔接模块的两端；锚杆植入模块包括植入壳体、顶底锚杆输出装置和帮部锚杆输出装置,植入壳体上端的固接有锚杆贮存桶,其上端开设有锚杆贮存槽；顶底、帮部锚杆输出装置均设置在植入壳体中；顶底锚杆输出装置和帮部锚杆输出装置的结构相同,均由输出喷嘴、第一和第二咬合驱动轮组成；挤出喷嘴模块包括模块间衔接块、两个衔接块和两个喷嘴。方法：确定出合适的缩小比例和打印参数；调配水泥基材料,连接物料泵送管道；启动打印；同步输出锚杆；形成支护系统；测试及分析。本发明能在相似物理模型的3D打印过程中自动化地同步植入缩尺锚杆支护构件。(A composite nozzle for 3D printing of similar physical models and a working method thereof are disclosed, wherein the nozzle comprises the following components: the anchor rod implanting module and the extrusion nozzle module are respectively arranged at two ends of the connecting module; the anchor rod implantation module comprises an implantation shell, a top-bottom anchor rod output device and a side anchor rod output device, wherein an anchor rod storage barrel is fixedly connected to the upper end of the implantation shell, and an anchor rod storage groove is formed in the upper end of the implantation shell; the top bottom anchor rod output device and the upper anchor rod output device are both arranged in the implantation shell; the top-bottom anchor rod output device and the upper anchor rod output device have the same structure and are respectively composed of an output nozzle, a first occlusion driving wheel and a second occlusion driving wheel; the extrusion nozzle module comprises an inter-module connection block, two connection blocks and two nozzles. The method comprises the following steps: determining a proper reduction ratio and printing parameters; preparing a cement-based material, and connecting a material pumping pipeline; starting printing; synchronously outputting the anchor rods; forming a support system; and (6) testing and analyzing. The invention can automatically and synchronously implant the scale anchor bolt supporting component in the 3D printing process of the similar physical model.)

1. A composite nozzle for 3D printing of similar physical models comprises an extrusion nozzle module (3), and is characterized by further comprising a connection module (1) and an anchor rod implantation module (2);

the anchor rod implanting module (2) and the extruding nozzle module (3) are respectively arranged at the left end and the right end of the connecting module (1);

the anchor rod implantation module (2) comprises an implantation shell (2-8), a top anchor rod output device (2-5) and a bottom anchor rod output device (2-6), the right end of the implantation shell (2-8) is fixedly connected with the left end of the linking module (1), the left side in the implantation shell is provided with a vertical bearing cavity, a transverse bearing cavity is arranged at the right side in the implantation shell (2-8), an anchor rod storage barrel (2-3) is fixedly connected at the left part of the upper end of the implantation shell, the right part of the upper end of the vertical bearing cavity is provided with a transversely extending anchor rod storage tank (2-1), an anchor rod storage barrel (2-3) is positioned above the vertical bearing cavity, the bottom of the anchor rod storage tank is communicated with the upper end of the vertical bearing cavity through a vertical discharge channel, the anchor rod storage tank (2-1) is positioned above the transverse bearing cavity, and the bottom of the anchor rod storage tank is communicated with the upper part of the transverse bearing cavity through a transverse discharge channel; the left end of the implantation shell (2-8) is provided with a first strip-shaped through hole extending transversely, the right end of the first strip-shaped through hole is communicated with the left end of the transverse bearing cavity, the left end of the first strip-shaped through hole is communicated with the outside of the left end of the implantation shell (2-8), the lower end of the implantation shell (2-8) is provided with a second strip-shaped through hole extending longitudinally, the upper end of the second strip-shaped through hole is communicated with the lower end of the vertical bearing cavity, and the lower end of the second strip-shaped through hole is communicated with the outside of the lower end of the implantation shell (2-8);

the top and bottom anchor rod output devices (2-5) are vertically arranged in the vertical bearing cavity, and the upper anchor rod output devices (2-6) are transversely arranged in the transverse bearing cavity; the top and bottom anchor rod output devices (2-5) and the upper anchor rod output devices (2-6) are identical in structure and are respectively composed of an output nozzle (2-7), a first meshing driving wheel (5-1) and a second meshing driving wheel (5-2); the center of the output nozzle (2-7) is provided with an axial through hole which is used for implanting an anchor rod (2-2) through the upper part or implanting an anchor rod (2-4) through the top and the bottom in a penetrating manner along the length direction, the output nozzle (2-7) is arranged in a first strip-shaped through hole or a second strip-shaped through hole, a first occlusion driving wheel (5-1) and a second occlusion driving wheel (5-2) are oppositely arranged at two sides of a vertical bearing cavity or a transverse bearing cavity, the first occlusion driving wheel (5-1) is rotatably connected to the inside of an implantation shell (2-8) through two first driving wheel shafts (5-3) fixedly connected to two sides of the center of the first occlusion driving wheel (5-2), one first driving wheel shaft (5-3) is connected with an output shaft of a first servo motor, and the second occlusion driving wheel shaft (5-2) is rotatably connected to two second driving wheel shafts (5-4) fixedly connected to two sides of the center of the second occlusion driving wheel shaft (5-2) in a rotatable manner Is implanted in the shell (2-8), and one second driving wheel shaft (5-4) is connected with the output shaft of the second servo motor; the first meshing driving wheel (5-1) and the second meshing driving wheel (5-2) are in opposite rotating fit and are used for meshing the upper part implanted anchor rod (2-2) or the top and bottom implanted anchor rod (2-4) and conveying the upper part implanted anchor rod (2-2) or the top and bottom implanted anchor rod (2-4) to the outside;

the extrusion nozzle module (3) comprises inter-module connection blocks (3-8), a nozzle A connection block (3-6), a nozzle B connection block (3-7), a nozzle A (3-1), a nozzle B (3-2) and a material input pipeline (3-11); the left end of the inter-module connection block (3-8) is fixedly connected with the right end of the connection module (1); the nozzle A connection block (3-6) and the nozzle B connection block (3-7) are fixedly connected to the right end of the inter-module connection block (3-8) in a front-back parallel mode, and a vertically through discharge channel A and a vertically through discharge channel B are formed in the interior of the inter-module connection block; a nozzle A valve (3-4) and a nozzle B valve (3-5) which are used for controlling the opening and closing of the discharge channel A and the discharge channel B are respectively arranged on the nozzle A connecting block (3-6) and the nozzle B connecting block (3-7); the nozzle A (3-1) and the nozzle B (3-2) are respectively and fixedly connected to the lower ends of the nozzle A connecting block (3-6) and the nozzle B connecting block (3-7), a nozzle gap (3-3) is formed between the nozzle A (3-1) and the nozzle B (3-2), and the distance between the nozzle gap (3-3) in the front and rear direction is larger than the outer diameter of a side implanted anchor rod (2-2) to be implanted or a top and bottom implanted anchor rod (2-4); the feed ends of the nozzle A (3-1) and the nozzle B (3-2) are respectively communicated with the discharge end of the discharge channel A and the discharge end of the discharge channel B; the material input pipelines (3-11) are arranged at the tops of the nozzle A connecting block (3-6) and the nozzle B connecting block (3-7), and the discharge ends of the material input pipelines are respectively communicated with the feed end of the discharge channel A and the feed end of the discharge channel B.

2. A compound nozzle for 3D printing of similar physical models according to claim 1, characterized in that the material inlet pipe (3-11) has fixedly connected to its outer part a flange (3-10) and fixedly connected to its inner part a changeover valve (3-9).

3. A compound nozzle for 3D printing of similar physical models according to claim 1, wherein the top-bottom anchor output device (2-5) and the upper anchor output device (2-6) further comprise two swing shafts (5-8), a first tension spring (5-5), a second tension spring (5-7), a lifting chute, a driving ejector rod (5-6), a first lifting gear (5-9), a second lifting gear (5-10) and a universal shaft (5-13);

the aperture of the first strip-shaped through hole and the aperture of the second strip-shaped through hole are larger than the size of the outer diameter of the output nozzle (2-7); one ends of the two swing shafts (5-8) are symmetrically and fixedly connected to two sides of the middle part of the output nozzle (2-7), and the other ends of the two swing shafts are rotatably connected to the inner side walls of two opposite sides of the first strip-shaped through hole or the second strip-shaped through hole, so that the output nozzle (2-7) can be arranged in the first strip-shaped through hole or the second strip-shaped through hole in a swing manner;

one end of a first tension spring (5-5) and one end of a second tension spring (5-7) are respectively connected to the outer side walls of the two opposite sides of the swing range center of the output nozzle (2-7) and are positioned on one side of the middle part of the output nozzle (2-7), the other end of the first tension spring (5-5) and the other end of the second tension spring (5-7) are respectively connected with the inner side walls of the two opposite sides of the first strip-shaped through hole and the second strip-shaped through hole, and the first tension spring (5-5) and the second tension spring (5-7) are used for providing opposite balance tension to enable the output nozzle (2-7) to be reset to a horizontal or vertical state;

the jacking chute is arranged in the implantation shell (2-8) and arranged at one side of the outer part of the inner end of the output nozzle (2-7), the length direction of the jacking chute is vertical to the output nozzle (2-7) reaching the horizontal or vertical state, and the jacking chute is communicated with the first strip-shaped through hole or the second strip-shaped through hole; the driving ejector rod (5-6) is arranged in the jacking chute in a sliding manner;

the first lifting gears (5-9) and the second lifting gears (5-10) are oppositely arranged at two sides of the driving mandril (5-6), the first lifting gears (5-9) are rotatably connected inside the implantation shell (2-8) through two first gear shafts (5-11) fixedly connected at two sides of the center of the first lifting gears, one first gear shaft (5-11) is connected with an output shaft of a first driving motor, the second lifting gears (5-10) are rotatably connected inside the implantation shell (2-8) through two second gear shafts (5-12) fixedly connected at two sides of the center of the second lifting gears, and one second gear shaft (5-12) is connected with an output shaft of a second driving motor; the first lifting gear (5-9) and the second lifting gear (5-10) are in opposite rotation fit and are used for meshing the driving ejector rod (5-6) and driving the driving ejector rod (5-6) to slide in a reciprocating manner along the length direction of the jacking chute;

the universal shafts (5-13) are arranged in the jacking sliding grooves, one ends of the universal shafts are hinged with the inner ends of the output nozzles (2-7), and the other ends of the universal shafts are hinged with one ends of the driving ejector rods (5-6).

4. The compound nozzle for 3D printing of similar physical models is characterized in that the front end of the connection module (1) is provided with a female connection groove (1-1) which is concave inwards, the rear end of the connection module is fixedly connected with a male connection head (1-2) which protrudes outwards, and the male connection head (1-2) and the connection module (1) are mutually matched in an inserted manner and used for being connected adjacently.

5. A compound nozzle for 3D printing of similar physical models according to claim 1, characterized in that the outer shell a is cube-shaped; the cross sections of the nozzle A (3-1) and the nozzle B (3-2) are in inverted trapezoidal structures with large upper parts and small lower parts.

6. A working method of a composite nozzle for 3D printing of similar physical models is characterized by comprising the following steps:

the method comprises the following steps: based on the real geological model, determining a proper reduction ratio, and further determining the sizes of the upper part implanted anchor rod (2-2) and the top and bottom implanted anchor rod (2-4); establishing a digital model of a similar physical model through a computer, splitting the model according to the model and the roadway condition, cutting and printing the left upper and the right upper of the roadway by taking a selected vertical line as a reference, and reasonably determining the printing sequence of each printing unit;

step two: exporting each printing unit into an stl format file, importing the stl format file into a 3D printer for slicing, and determining printing parameters;

step three: reasonably allocating cement-based materials according to the occurrence condition of an original model rock stratum, determining the number of required composite nozzles according to the thickness of the model and the row spacing between supports, connecting adjacent composite nozzles through mutual splicing of a connecting male head (1-2) and a linking module (1), and ensuring stable and reliable connection; a material pumping pipeline is connected through the switching valve (3-9) and the flange (3-10); further determining whether to open the valve (3-4) of the nozzle A and the valve (3-5) of the nozzle B according to the thickness of the model;

step four: respectively placing top and bottom implanted anchor rods (2-4) and side implanted anchor rods (2-2) with the sizes reduced in proportion into an anchor rod storage barrel (2-3) and an anchor rod storage groove (2-1), respectively placing first anchor rods in the anchor rod storage barrel (2-3) and the anchor rod storage groove (2-1) into output nozzles (2-7) of a top and bottom anchor rod output device (2-5) and a side anchor rod output device (2-6), starting a system, and operating the top and bottom anchor rod output device (2-5) and the side anchor rod output device (2-6) to enable the exposed lengths of the anchor rods to be in right contact with the upper surface of a printed layer, namely the upper surface of the previous printed layer (4-3);

step five: starting a 3D printer, printing a similar physical model (4) in a layer-by-layer accumulation mode, and distinguishing layers by an interlayer spacing line (4-1); sequentially forming the current printing layer (4-2) along with the forward movement of the composite nozzles, simultaneously, separating printing units formed by the single composite nozzles A (3-1) and the nozzles B (3-2) by using a gap separating trace (4-5), and separating adjacent composite nozzles by using a unit separating trace (4-6);

in the printing process, the first servo motor and the second servo motor are controlled to be started in real time according to the printing parameters set in the step two at the forming position of the roadway, so that the first meshing driving wheel (5-1) and the second meshing driving wheel (5-2) are driven to rotate oppositely, the anchor rod is inserted into the previous printing layer (4-3) by the top-bottom anchor rod output device (2-5) and the upper anchor rod output device (2-6), the inserting depth is in direct proportion to the number of rotation turns of the servo motors, the operation of the first servo motor and the operation of the second servo motor are repellent to the forward movement of the composite nozzle, the former operates, and the latter waits until the previous layer of implanted anchor rod (4-7) is formed; after the first servo motor and the second servo motor are stopped, the composite nozzle is controlled to move forwards continuously, the inserted previous layer of implanted anchor rod (4-7) passes through the nozzle gap (3-3) and is covered by materials extruded by the nozzle A (3-1) and the nozzle B (3-2) to form the current layer of implanted anchor rod (4-4);

step six: after all the units are printed, maintaining for 10 days, assembling all the units similar to the physical model (4) to form a complete model, then installing a ladder beam and a steel belt with reduced sizes in a specific supporting area according to engineering situations, enabling holes of the ladder beam and the steel belt to correspond to the positions of anchor rods, and then installing a tray; finally, selecting nuts with specific labels according to the parameters of the size-reduced anchor rods, and screwing the nuts to form an integral supporting system;

step seven: and continuing maintaining the completed 3D printing similar physical model, and carrying out subsequent test analysis work.

7. The working method of the compound nozzle for 3D printing of the similar physical model is characterized in that in the second step, the printing parameters comprise information of layer height, printing speed, anchor rod installation position and anchor rod installation waiting time.

8. A working method of a compound nozzle for 3D printing of similar physical models according to claim 7 is characterized in that in the third step, the nozzle A valve (3-4) and the nozzle B valve (3-5) are opened, so that the nozzle A (3-1) and the nozzle B (3-2) extrude at least materials with the height of not less than 20cm for fluency test.

9. The working method of the composite nozzle for 3D printing of the similar physical model is characterized in that in the fifth step, in anchor bolt support of a roadway side part, at a specific supporting position, the nozzle A (3-1) and the nozzle B (3-2) are respectively controlled to stop extruding materials by controlling the nozzle A valve (3-4) and the nozzle B valve (3-5), the integral composite nozzle is controlled to be lifted upwards by 15mm, then the integral composite nozzle runs to the far end of the model in an empty mode and rotates 180 degrees, an anchor bolt (2-2) to be implanted on the side part and an anchor bolt (2-4) to be implanted on the top and the bottom are opposite to the side part, then the composite nozzle is descended to the height required to be subjected to anchor bolt support, and finally the composite nozzle returns to the supporting position; starting a first servo motor and a second servo motor to drive a first meshing driving wheel (5-1) and a second meshing driving wheel (5-2) to rotate, and inserting the anchor rod into the printed layer through a top anchor rod output device (2-5) and a bottom anchor rod output device (2-6); after the steps, the integral composite nozzle is idle to the far end of the model, rotates 180 degrees, then raises the composite nozzle to the printing height of the current layer, returns to the extrusion stopping position, and starts the subsequent printing process.

10. The working method of the compound nozzle for 3D printing of the similar physical model according to claim 9, wherein in the fifth step, when the inclined anchor rod needs to be implanted in the printing process, the nozzle A (3-1) and the nozzle B (3-2) are controlled to stop extruding the material at the position where the inclined anchor rod needs to be implanted, then the first driving motor and the second driving motor are started according to the inclination angle requirement to synchronously drive the first lifting gear (5-9) and the second lifting gear (5-10) so as to drive the driving ejector rod (5-6) to ascend or descend for the set height, and further drive the output nozzle (2-7) to ascend and descend around the swinging shaft (5-8) through the universal shaft (5-13), wherein the set angle is in direct proportion to the number of rotation turns of the first driving motor and the second driving motor, then, the first servo motor and the second servo motor are controlled to be started so as to push out the anchor rod through the first meshing driving wheel (5-1) and the second meshing driving wheel (5-2), and the anchor rod is inserted into a corresponding position and a corresponding depth; when the implantation of the inclined anchor rod is completed, the first driving motor and the second driving motor drive the first lifting gear (5-9) and the second lifting gear (5-10) to drive the driving ejector rod (5-6) to restore to the original position, and the output nozzle (2-7) is restored to the horizontal or vertical state under the combined action of the first tension spring (5-5) and the second tension spring (5-7).

Technical Field

The invention belongs to the technical field of concrete 3D printing in the field of mine rock soil, and particularly relates to a composite nozzle for 3D printing of similar physical models and a working method thereof.

Background

The method is generally carried out in a laboratory, and through constructing a scale model and simulating real geological conditions and excavation steps, the characteristics of a rock-soil body in the deformation failure process, such as a displacement field, a stress field, roadway deformation and the like, can be obtained in a loading mode. The method is greatly applied to related research fields due to low economic cost, relatively simple operation process and relatively visual and clear result, and is one of the indispensable methods for researching the deformation of the rock and soil mass in the laboratory at present.

At present, materials for similar physical simulation are mainly traditional materials such as yellow sand, cement, mica sheets and the like, proper aggregates are selected after calculation according to a specific similarity ratio, then stacking is carried out layer by layer in a manual mode, and after stacking of each layer is completed, manual tamping is carried out, so that the whole model is finally formed. In the prior art, the similar model constructed and formed based on the method has the following defects: the interlayer strength is difficult to control, the thickness of the rock stratum is difficult to maintain uniform, the rock stratum strength cannot be matched with a target rock stratum, the manual operation amount is large, the maintenance of the test piece is long, the influence of environmental factors is large, and the like. Therefore, most of the traditional similar physical simulation results are difficult to obtain according with real situations, the subjective influence of operators is large, and rock stratum bridging is difficult to occur frequently. How to effectively solve the problems of obvious distortion phenomenon, low result accuracy and the like in the current similar physical simulation test is not only relatively important to the research of the mining field, but also has certain reference significance to the related research of the adjacent engineering field.

3D printing has been a new technology and has been developed rapidly in recent years, and as an additive manufacturing technology, it has advantages that the traditional casting technology does not have, and can form complex components, so that the manufacturing process of the parts which are difficult to machine and form in the past becomes simple, economical and reliable, and at the same time, the strength of the finished product can be effectively guaranteed. At present, there are many kinds of materials for 3D printing, such as polylactic acid materials, photosensitive resin materials, metal powder materials, concrete materials, and the like. In recent years, the concrete 3D printing technology has been rapidly developed in the construction field, and has the advantages of low material consumption, less personnel involvement, high automation degree, simple and easy molding of complex target components, and the like. The advantages of 3D concrete printing are effectively combined, a similar physical model of a mine can be constructed, the model is constructed through a computer, high accuracy can be guaranteed, printing of a simulated rock stratum is high in autonomy, and certain complex coal rock strata can be copied. However, in the construction of a similar physical model of a mine, it is also necessary to implant anchors simultaneously in order to simulate real geological conditions more effectively. In the prior art, the 3D concrete printing nozzle with the synchronous anchor rod implanting function is not provided, so that the printing efficiency of similar physical models is reduced, and meanwhile, the anchor rod is also required to be implanted manually and synchronously, so that the labor intensity of operators is increased.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the composite nozzle for 3D printing of the similar physical model and the working method thereof, the nozzle can be automatically and synchronously implanted into the reduced-size anchor bolt supporting member in the 3D printing process of the similar physical model, the implantation difficulty of the supporting member can be reduced, and the labor intensity of operators can be effectively reduced; the method has simple steps, can quickly and accurately construct a similar physical model of the ore removal mountain by combining the advantages of 3D concrete printing, can effectively reduce the number and cost of participators, and can effectively duplicate a complex coal rock stratum structure.

The invention provides a composite nozzle for 3D printing of similar physical models, which comprises an extrusion nozzle module, a connection module and an anchor rod implantation module;

the anchor rod implanting module and the extrusion nozzle module are respectively arranged at the left end and the right end of the connecting module;

the anchor rod implanting module comprises an implanting shell, a top-bottom anchor rod output device and a side anchor rod output device, the right end of the implanting shell is fixedly connected to the left end of the connecting module, a vertical bearing cavity is formed in the left side of the implanting shell, a transverse bearing cavity is formed in the right side of the implanting shell, an anchor rod storage barrel is fixedly connected to the left portion of the upper end of the implanting shell, a transversely extending anchor rod storage groove is formed in the right portion of the upper end of the implanting shell, the anchor rod storage barrel is located above the vertical bearing cavity, the bottom of the anchor rod storage barrel is communicated with the upper end of the vertical bearing cavity through a vertical discharging channel, the anchor rod storage groove is located above the transverse bearing cavity, and the bottom of the anchor rod storage groove is communicated with the upper portion of the transverse bearing cavity through a transverse discharging channel; the left end of the implantation shell is provided with a first strip-shaped through hole extending transversely, the right end of the first strip-shaped through hole is communicated with the left end of the transverse bearing cavity, the left end of the first strip-shaped through hole is communicated with the outside of the left end of the implantation shell, the lower end of the implantation shell is provided with a second strip-shaped through hole extending longitudinally, the upper end of the second strip-shaped through hole is communicated with the lower end of the vertical bearing cavity, and the lower end of the second strip-shaped through hole is communicated with the outside of the lower end of the implantation shell;

the top and bottom anchor rod output device is vertically arranged in the vertical bearing cavity, and the upper anchor rod output device is transversely arranged in the transverse bearing cavity; the top and bottom anchor rod output device and the upper anchor rod output device are identical in structure and are composed of an output nozzle, a first meshing driving wheel and a second meshing driving wheel; the center of the output nozzle is provided with an axial through hole which is used for implanting an anchor rod through the upper part or implanting the anchor rod through the top and the bottom in a penetrating manner along the length direction, the output nozzle is arranged in the first strip-shaped through hole or the second strip-shaped through hole, the first occlusion driving wheel and the second occlusion driving wheel are oppositely arranged at two sides of the vertical bearing cavity or the transverse bearing cavity, the first occlusion driving wheel is rotatably connected into the implantation shell through two first driving wheel shafts which are fixedly connected at two sides of the center of the first occlusion driving wheel, one first driving wheel shaft is connected with the output shaft of the first servo motor, the second occlusion driving wheel is rotatably connected into the implantation shell through two second driving wheel shafts which are fixedly connected at two sides of the center of the second occlusion driving wheel shaft, and one second driving wheel shaft is connected with the output shaft of the second servo motor; the first meshing driving wheel and the second meshing driving wheel are in opposite rotating fit and are used for meshing the side part implanted anchor rod or the top and bottom implanted anchor rod and conveying the side part implanted anchor rod or the top and bottom implanted anchor rod to the outside;

the extrusion nozzle module comprises an inter-module connection block, a nozzle A connection block, a nozzle B connection block, a nozzle A, a nozzle B and a material input pipeline; the left end of the inter-module connection block is fixedly connected with the right end of the connection module; the nozzle A connecting block and the nozzle B connecting block are fixedly connected to the right end of the inter-module connecting block in a front-back parallel mode, and a vertically through discharge channel A and a vertically through discharge channel B are formed in the nozzle A connecting block and the nozzle B connecting block respectively; a nozzle A valve and a nozzle B valve for controlling the opening and closing of the discharge channel A and the discharge channel B are respectively arranged on the nozzle A connecting block and the nozzle B connecting block; the nozzle A and the nozzle B are respectively and fixedly connected to the lower ends of the nozzle A connection block and the nozzle B connection block, a nozzle gap is formed between the nozzle A and the nozzle B, and the distance of the nozzle gap in the front-back direction is larger than the outer diameter of a side implanted anchor rod to be implanted or a top-bottom implanted anchor rod to be implanted; the feed ends of the nozzle A and the nozzle B are respectively communicated with the discharge end of the discharge channel A and the discharge end of the discharge channel B; the material input pipeline is arranged at the tops of the nozzle A connection block and the nozzle B connection block, and the discharge end of the material input pipeline is communicated with the feed end of the discharge channel A and the feed end of the discharge channel B respectively.

Furthermore, in order to conveniently connect a feeding pipeline or material output equipment, the outer part of the feeding end of the material input pipeline is fixedly connected with a flange, and a switching valve is fixedly connected in the feeding end.

Furthermore, in order to realize the automatic adjustment of the inclination angle of the output anchor rod and improve the application range of the nozzle, the top-bottom anchor rod output device and the upper anchor rod output device further comprise two swinging shafts, a first tension spring, a second tension spring, a jacking chute, a driving ejector rod, a first lifting gear, a second lifting gear and a universal shaft;

the aperture of the first strip-shaped through hole and the aperture of the second strip-shaped through hole are larger than the size of the outer diameter of the output nozzle; one ends of the two swing shafts are symmetrically and fixedly connected to two sides of the middle part of the output nozzle, and the other ends of the two swing shafts are rotatably connected to the inner side walls of two opposite sides of the first strip-shaped through hole or the second strip-shaped through hole, so that the output nozzle can be arranged in the first strip-shaped through hole or the second strip-shaped through hole in a swinging manner;

one end of a first tension spring and one end of a second tension spring are respectively connected to the outer side walls of the two opposite sides of the swing range center of the output nozzle and are positioned on one side of the middle part of the output nozzle, the other end of the first tension spring and the other end of the second tension spring are respectively connected with the inner side walls of the two opposite sides of the first strip-shaped through hole and the second strip-shaped through hole, and the first tension spring and the second tension spring are used for providing opposite balance tension to enable the output nozzle to be reset to a horizontal or vertical state;

the jacking chute is arranged in the implantation shell and arranged on one side of the outer part of the inner end of the output nozzle, the length direction of the jacking chute is vertical to the output nozzle reaching a horizontal or vertical state, and the jacking chute is communicated with the first strip-shaped through hole or the second strip-shaped through hole; the driving ejector rod is arranged in the jacking chute in a sliding manner;

the first lifting gear and the second lifting gear are oppositely arranged on two sides of the driving ejector rod, the first lifting gear is rotatably connected into the implantation shell through two first gear shafts fixedly connected to two sides of the center of the first lifting gear, one first gear shaft is connected with an output shaft of the first driving motor, the second lifting gear is rotatably connected into the implantation shell through two second gear shafts fixedly connected to two sides of the center of the second lifting gear, and one second gear shaft is connected with an output shaft of the second driving motor; the first lifting gear and the second lifting gear are in opposite rotating fit and are used for meshing the driving ejector rod and driving the driving ejector rod to slide in a reciprocating manner along the length direction of the jacking chute;

the universal shaft is arranged in the jacking sliding groove, one end of the universal shaft is hinged with the inner end of the output nozzle, and the other end of the universal shaft is hinged with one end of the driving ejector rod.

Furthermore, in order to conveniently cascade a plurality of compound nozzles, the front end of the linking module is provided with a female connecting groove which is concave towards the inside, the rear end of the linking module is fixedly connected with a male connecting head which protrudes towards the outside, and the male connecting head and the linking module are mutually spliced and matched for being connected adjacently.

Preferably, the outer shell A is cubic; the cross sections of the nozzle A and the nozzle B are of inverted trapezoidal structures with large upper parts and small lower parts.

In the technical scheme, the anchor rod implanting module and the extrusion nozzle module are respectively arranged on the left side and the right side of the connecting module, and the top bottom anchor rod output device and the upper part anchor rod output device are arranged in the anchor rod implanting module, so that the top bottom anchor rod and the upper part anchor rod can be effectively implanted in a 3D printing process synchronously, and the problems of obvious distortion phenomenon and low result accuracy in a similar physical simulation test in the prior art can be effectively solved. Through the cooperation setting that makes first interlock drive wheel and second interlock drive wheel, can be convenient pass through output nozzle with the stock and export to outside to be convenient for automatic completion anchor rod's the insertion process. Two swing shafts are fixedly connected to two opposite sides of the output nozzle, so that the output nozzle can have a certain swing amplitude in the first strip-shaped through hole or the second strip-shaped through hole. Through the relative cooperation setting of first lifting gear and second lifting gear, the reciprocating motion through the drive ejector pin that can be convenient drives the swing range of delivery nozzle one end to change delivery nozzle's that can be automatic inclination can realize the synchronous implantation of specific inclination stock. The nozzle can automatically and synchronously implant the scaled anchor bolt supporting member in the 3D printing process of similar physical models, can reduce the implantation difficulty of the supporting member, and can effectively reduce the labor intensity of operators.

The invention also provides a working method of the composite nozzle for 3D printing of the similar physical model, which comprises the following steps:

the method comprises the following steps: determining a proper reduction ratio based on the real geological model, and further determining the sizes of the upper part implanted anchor rod and the top and bottom implanted anchor rod; establishing a digital model of a similar physical model through a computer, splitting the model according to the model and the roadway condition, cutting and printing the left upper and the right upper of the roadway by taking a selected vertical line as a reference, and reasonably determining the printing sequence of each printing unit;

step two: exporting each printing unit into an stl format file, importing the stl format file into a 3D printer for slicing, and determining printing parameters;

step three: reasonably allocating cement-based materials according to the occurrence condition of an original model rock stratum, and determining the number of required composite nozzles according to the thickness of the model and the row spacing between supports, so that adjacent composite nozzles are connected by mutual insertion of a connecting male head and a linking module, and stable and reliable connection is ensured; the material pumping pipeline is connected with the flange through the switching valve; further determining whether to open a nozzle A valve and a nozzle B valve according to the thickness of the model;

step four: respectively placing the top-bottom implanted anchor rod and the upper implanted anchor rod with the sizes reduced in proportion into an anchor rod storage barrel and an anchor rod storage groove, respectively placing a first anchor rod in the anchor rod storage barrel and the anchor rod storage groove into output nozzles of a top-bottom anchor rod output device and an upper anchor rod output device, starting a system and operating the top-bottom anchor rod output device and the upper anchor rod output device to enable the exposed length of the anchor rod to be just contacted with the upper surface of a printed layer, namely the upper surface of the previous printed layer;

step five: starting a 3D printer, printing similar physical models in a layer-by-layer accumulation mode, and distinguishing layers by using interlayer spacing lines; the current printing layer is sequentially molded along with the forward movement of the composite nozzles, meanwhile, the printing units respectively molded by the single composite nozzles A and the nozzles B are distinguished by gap-reserved separating traces, and the adjacent composite nozzles are distinguished by unit separating traces;

in the printing process, the first servo motor and the second servo motor are controlled to start in real time according to the printing parameters set in the step two at the forming position of the roadway, so that the first meshing driving wheel and the second meshing driving wheel are driven to rotate oppositely, the anchor rod is inserted into the previous printing layer by the top-bottom anchor rod output device and the upper-part anchor rod output device, the inserting depth is in direct proportion to the number of rotation turns of the servo motors, the operation of the first servo motor and the operation of the second servo motor are repellent to the forward movement of the composite nozzle, the former operates, and the latter waits until the previous layer of implanted anchor rod is formed; after the first servo motor and the second servo motor stop, the composite nozzle is controlled to move forwards continuously, the inserted previous layer of the implanted anchor rod passes through a nozzle gap and is covered by materials extruded by the nozzle A and the nozzle B, and the current layer of the implanted anchor rod is formed;

step six: after all the units are printed, maintaining for 10 days, assembling all the units similar to the physical model to form a complete model, then installing a ladder beam and a steel belt with reduced sizes in a specific supporting area according to engineering conditions, enabling holes of the ladder beam and the steel belt to correspond to anchor rod positions, and then installing a tray; finally, selecting nuts with specific labels according to the parameters of the size-reduced anchor rods, and screwing the nuts to form an integral supporting system;

step seven: and continuing maintaining the completed 3D printing similar physical model, and carrying out subsequent test analysis work.

Preferably, in the second step, the printing parameters include information of a layer height, a printing speed, a bolting position and a bolting waiting time.

Preferably, in the third step, the valve of the nozzle A and the valve of the nozzle B are opened, so that the nozzle A and the nozzle B extrude at least materials with the height of not less than 20cm for the fluency test.

Further, in order to improve the general range and print out similar physical models better, in the fifth step, in anchor bolt support of the roadway side part, at a specific supporting position needing to be supported, the nozzle A and the nozzle B are controlled by controlling the valve of the nozzle A and the valve of the nozzle B to stop extruding materials respectively, the integral composite nozzle is controlled to lift upwards by 15mm, then the composite nozzle is idle to the far end of the model and rotates 180 degrees, an anchor bolt to be implanted into the side part is directly opposite to the side part with the anchor bolt implanted into the top and the bottom, then the composite nozzle is descended to the height needing to be supported by the anchor bolt, and finally the composite nozzle returns to the supporting position needing to be supported; starting a first servo motor and a second servo motor to drive a first meshing driving wheel and a second meshing driving wheel to rotate, and inserting the anchor rod into the printed layer through a top-bottom anchor rod output device and a side anchor rod output device; after the steps, the integral composite nozzle is idle to the far end of the model, rotates 180 degrees, then raises the composite nozzle to the printing height of the current layer, returns to the extrusion stopping position, and starts the subsequent printing process.

Furthermore, in order to realize the synchronous insertion of the inclined anchor rod and improve the universality of the inclined anchor rod, in the fifth step, when the inclined anchor rod needs to be implanted in the printing process, firstly controlling the nozzle A and the nozzle B to stop extruding materials at a position where the inclined anchor rod needs to be implanted, then starting the first driving motor and the second driving motor according to the requirement of the inclined angle to synchronously drive the first lifting gear and the second lifting gear so as to drive the driving ejector rod to ascend or descend for setting the height, further driving the output nozzle to ascend and descend around the swinging shaft by the universal shaft for setting an angle, wherein the angle is in direct proportion to the number of rotation turns of the first driving motor and the second driving motor, and then controlling the first servo motor and the second servo motor to start so as to push out the anchor rod through the first meshing driving wheel and the second meshing driving wheel and insert the anchor rod to a corresponding position and a corresponding depth; when the implantation of the inclined anchor rod is completed, the first driving motor and the second driving motor drive the first lifting gear and the second lifting gear to drive the driving ejector rod to recover to the original position, and the output nozzle is reset to be in a horizontal or vertical state under the combined action of the first tension spring and the second tension spring.

The method has simple steps and low implementation cost, can quickly and accurately realize the 3D printing construction of the similar physical model, and can synchronously implant the anchor bolt supporting member in the 3D printing process of the similar physical model, so that the implantation difficulty of the supporting member is greatly reduced, and the automation degree is improved. The method can also realize the implantation of the inclined anchor rod, is favorable for realizing the accurate reduction of the real model, and thus can provide a brand new means for the similar physical simulation technology of the mine.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic diagram of a composite nozzle printing process according to the present invention;

fig. 3 is a schematic structural view of the top-bottom anchor output device or the upper anchor output device in the invention.

In the figure: 1. a linking module 2, an anchor rod implanting module 3, an extrusion nozzle module 4 and a similar physical model;

1-1, connecting a female groove and 1-2, and connecting a male head;

2-1, an anchor rod storage groove, 2-2, a side implanted anchor rod, 2-3, an anchor rod storage barrel, 2-4, a top and bottom implanted anchor rod, 2-5, a top and bottom anchor rod output device, 2-6, a side anchor rod output device, 2-7, an output nozzle, 2-8 and an implanted shell;

3-1 parts of nozzles A, 3-2 parts of nozzles B, 3-3 parts of nozzle gaps, 3-4 parts of nozzle A valves, 3-5 parts of nozzle B valves, 3-6 parts of nozzle A connecting blocks, 3-7 parts of nozzle B connecting blocks, 3-8 parts of inter-module connecting blocks, 3-9 parts of switching valves, 3-10 parts of flanges, 3-11 parts of material input pipelines;

4-1, an interlayer spacing line, 4-2, a current printing layer, 4-3, a previous printing layer, 4-4, implanting an anchor rod into the current layer, 4-5, a gap spacing trace line, 4-6, a unit spacing trace line, 4-7 and implanting an anchor rod into the previous layer;

5-1 parts of a first meshing driving wheel, 5-2 parts of a second meshing driving wheel, 5-3 parts of a first driving wheel shaft, 5-4 parts of a second driving wheel shaft, 5-5 parts of a first tension spring, 5-6 parts of a driving ejector rod, 5-7 parts of a second tension spring, 5-8 parts of a swinging shaft, 5-9 parts of a first lifting gear, 5-10 parts of a second lifting gear, 5-11 parts of a first gear shaft, 5-12 parts of a second gear shaft, 5-13 parts of a universal shaft.

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 1 to 3, the present invention provides a composite nozzle for 3D printing of similar physical models, which includes an extrusion nozzle module 3, a joining module 1 and an anchor rod implanting module 2;

the anchor rod implanting module 2 and the extrusion nozzle module 3 are respectively arranged at the left end and the right end of the connecting module 1;

the anchor rod implanting module 2 comprises an implanting shell 2-8, a top-bottom anchor rod output device 2-5 and a side anchor rod output device 2-6, the right end of the implanting shell 2-8 is fixedly connected with the left end of the connecting module 1, a vertical bearing cavity is arranged on the left side inside the implanting shell, a transverse bearing cavity is arranged on the right side inside the implanting shell, an anchor rod storage barrel 2-3 is fixedly connected with the left part of the upper end of the implanting shell 2-8, a transversely extending anchor rod storage groove 2-1 is arranged on the right part of the upper end of the implanting shell, the anchor rod storage barrel 2-3 is used for bearing a top-bottom implanting anchor rod 2-4 with a proportionally reduced size, and the anchor rod storage groove 2-1 is used for bearing the side implanting anchor rod 2-2 with the proportionally reduced size;

the anchor rod storage barrel 2-3 is positioned above the vertical bearing cavity, the bottom of the anchor rod storage barrel is communicated with the upper end of the vertical bearing cavity through a vertical discharge channel, the anchor rod storage tank 2-1 is positioned above the transverse bearing cavity, and the bottom of the anchor rod storage tank is communicated with the upper part of the transverse bearing cavity through a transverse discharge channel; the left end of the implantation shell 2-8 is provided with a first strip-shaped through hole extending transversely, the right end of the first strip-shaped through hole is communicated with the left end of the transverse bearing cavity, the left end of the first strip-shaped through hole is communicated with the outside of the left end of the implantation shell 2-8, the lower end of the implantation shell 2-8 is provided with a second strip-shaped through hole extending longitudinally, the upper end of the second strip-shaped through hole is communicated with the lower end of the vertical bearing cavity, and the lower end of the second strip-shaped through hole is communicated with the outside of the lower end of the implantation shell 2-8;

the top and bottom anchor rod output devices 2-5 are vertically arranged in the vertical bearing cavity, and the upper anchor rod output devices 2-6 are transversely arranged in the transverse bearing cavity; the top and bottom anchor rod output device 2-5 and the upper anchor rod output device 2-6 are identical in structure and are composed of an output nozzle 2-7, a first meshing driving wheel 5-1 and a second meshing driving wheel 5-2; the center of the output nozzle 2-7 is provided with an axial through hole which is used for implanting the anchor rod 2-2 through the upper part or implanting the anchor rod 2-4 through the top and the bottom in a penetrating way along the length direction, the output nozzle 2-7 is arranged in the first strip-shaped through hole or the second strip-shaped through hole, the first meshed driving wheel 5-1 and the second meshed driving wheel 5-2 are oppositely arranged at two sides of the vertical bearing cavity or the transverse bearing cavity, a conveying channel for conveying the anchor rod is formed between the first meshed driving wheel 5-1 and the second meshed driving wheel 5-2, the feeding end of the conveying channel corresponds to the vertical discharging channel or the transverse discharging channel, the discharge end of the device corresponds to a pore channel in the output nozzle 2-7, wherein in the top-bottom anchor rod output device 2-5, the first meshing driving wheel 5-1 and the second meshing driving wheel 5-2 are oppositely arranged at the upper side and the lower side of the discharge end of the transverse discharge channel; in the upper anchor rod output device 2-6, a first meshing driving wheel 5-1 and a second meshing driving wheel 5-2 are oppositely arranged at the left side and the right side of the discharge end of the vertical discharge channel;

the first meshing driving wheel 5-1 is rotatably connected inside the implantation shell 2-8 through two first driving wheel shafts 5-3 fixedly connected to two sides of the center of the first meshing driving wheel and is rotatably arranged in the transverse bearing cavity or the vertical bearing cavity; one first driving wheel shaft 5-3 is connected with an output shaft of the first servo motor, and the second meshing driving wheel 5-2 is rotatably connected inside the implanting shell 2-8 through two second driving wheel shafts 5-4 fixedly connected to the two sides of the center of the second meshing driving wheel shaft and is rotatably arranged in the transverse bearing cavity or the vertical bearing cavity; one second driving wheel shaft 5-4 is connected with an output shaft of the second servo motor; the first meshing driving wheel 5-1 and the second meshing driving wheel 5-2 are in opposite rotation fit and are used for meshing the upper part implanted anchor rod 2-2 or the top and bottom implanted anchor rod 2-4 and conveying the upper part implanted anchor rod 2-2 or the top and bottom implanted anchor rod 2-4 to the outside;

preferably, the vertical discharge channel is just suitable for a top-bottom implanted anchor rod 2-4 to pass through, so that the top-bottom implanted anchor rod 2-4 passing through the vertical discharge channel can smoothly enter the conveying channel formed between the first meshing driving wheel 5-1 and the second meshing driving wheel 5-2, and further can conveniently enter the second strip-shaped channel and enter the output nozzle 2-7;

preferably, the transverse discharge channel is just suitable for the upper part implanted anchor rod 2-2 to pass through, so that the upper part implanted anchor rod 2-2 passing through the transverse discharge channel can smoothly enter the conveying channel formed between the first meshing driving wheel 5-1 and the second meshing driving wheel 5-2, and further can conveniently enter the second strip-shaped channel and enter the output nozzle 2-7; preferably, the transverse discharge channel is a parallelogram discharge channel which is inclined from low left to high right, so that the left end of the anchor rod 2-2 implanted through the lowermost one of the upper parts can automatically enter the transverse bearing cavity and the conveying channel formed between the first meshing driving wheel 5-1 and the second meshing driving wheel 5-2;

the extrusion nozzle module 3 comprises inter-module connection blocks 3-8, a nozzle A connection block 3-6, a nozzle B connection block 3-7, a nozzle A3-1, a nozzle B3-2 and a material input pipeline 3-11; the left ends of the inter-module connection blocks 3-8 are fixedly connected to the right end of the connection module 1; the nozzle A connecting block 3-6 and the nozzle B connecting block 3-7 are fixedly connected to the right end of the inter-module connecting block 3-8 in a front-back side-by-side mode, and a vertically through discharge channel A and a vertically through discharge channel B are formed in the interior of the inter-module connecting block; the nozzle A connecting block 3-6 and the nozzle B connecting block 3-7 are respectively provided with a nozzle A valve 3-4 and a nozzle B valve 3-5 which are used for controlling the opening and closing of the discharge channel A and the discharge channel B; the nozzle A3-1 and the nozzle B3-2 are fixedly connected to the lower ends of the nozzle A connecting block 3-6 and the nozzle B connecting block 3-7 respectively, a nozzle gap 3-3 is formed between the nozzle A3-1 and the nozzle B3-2, and the distance between the nozzle gap 3-3 in the front-back direction is larger than the outer diameter of the side part implanted anchor rod 2-2 or the top-bottom implanted anchor rod 2-4 to be implanted; the feed ends of nozzle A3-1 and nozzle B3-2 are in communication with the discharge end of discharge channel A and the discharge end of discharge channel B, respectively; the material input pipelines 3-11 are arranged at the tops of the nozzle A connecting block 3-6 and the nozzle B connecting block 3-7, and the discharge ends of the material input pipelines are respectively communicated with the feed end of the discharge channel A and the feed end of the discharge channel B.

In order to facilitate connection of a feeding pipeline or material output equipment, the outer part of the feeding end of the material input pipeline 3-11 is fixedly connected with a flange 3-10, and the middle part of the feeding end is fixedly connected with a changeover valve 3-9.

In order to realize the automatic adjustment of the inclination angle of the output anchor rod and improve the application range of the nozzle, the top-bottom anchor rod output device 2-5 and the upper anchor rod output device 2-6 also comprise two swinging shafts 5-8, a first tension spring 5-5, a second tension spring 5-7, a jacking chute, a driving ejector rod 5-6, a first lifting gear 5-9, a second lifting gear 5-10 and a universal shaft 5-13;

the aperture of the first strip-shaped through hole and the aperture of the second strip-shaped through hole are larger than the size of the outer diameter of the output nozzle 2-7; one ends of the two swing shafts 5-8 are symmetrically and fixedly connected to two sides of the middle part of the output nozzle 2-7, and the other ends of the two swing shafts are rotatably connected to the inner side walls of two opposite sides of the first strip-shaped through hole or the second strip-shaped through hole, so that the output nozzle 2-7 can be arranged in the first strip-shaped through hole or the second strip-shaped through hole in a swing manner;

one end of a first tension spring 5-5 and one end of a second tension spring 5-7 are respectively connected to the outer side walls of the two opposite sides of the swing range center of the output nozzle 2-7 and are positioned at one side of the middle part of the output nozzle 2-7, the other end of the first tension spring 5-5 and the other end of the second tension spring 5-7 are respectively connected with the inner side walls of the two opposite sides of the first strip-shaped through hole and the second strip-shaped through hole, and the first tension spring 5-5 and the second tension spring 5-7 are used for providing opposite balance tension to enable the output nozzle 2-7 to be reset to a horizontal or vertical state;

in the top-bottom anchor rod output device 2-5, a first tension spring 5-5 and a second tension spring 5-7 are used for providing opposite balance tension to enable an output nozzle 2-7 to be reset to a vertical state; in the upper anchor rod output device 2-6, a first tension spring 5-5 and a second tension spring 5-7 are used for providing opposite balance tension to enable the output nozzle 2-7 to be reset to a horizontal state;

the jacking chute is arranged in the implantation shell 2-8 and at one side of the outer part of the inner end of the output nozzle 2-7, the length direction of the jacking chute is vertical to the output nozzle 2-7 reaching a horizontal or vertical state, and the jacking chute is communicated with the first strip-shaped through hole or the second strip-shaped through hole; in the top-bottom anchor rod output device 2-5, the length direction of the jacking chute is vertical to the output nozzle 2-7 which reaches a vertical state; in the upper anchor rod output device 2-6, the length direction of the jacking chute is vertical to the output nozzle 2-7 reaching the horizontal state; the driving ejector rod 5-6 is slidably arranged in the jacking chute;

the first lifting gears 5-9 and the second lifting gears 5-10 are oppositely arranged at two sides of the driving mandril 5-6, the first lifting gears 5-9 are rotatably connected inside the implantation shell 2-8 through two first gear shafts 5-11 fixedly connected at two sides of the center of the first lifting gears 5-9, one first gear shaft 5-11 is connected with an output shaft of the first driving motor, the second lifting gears 5-10 are rotatably connected inside the implantation shell 2-8 through two second gear shafts 5-12 fixedly connected at two sides of the center of the second lifting gears 5-10, and one second gear shaft 5-12 is connected with an output shaft of the second driving motor; the first lifting gear 5-9 and the second lifting gear 5-10 are in opposite rotating fit and are used for meshing the driving ejector rod 5-6 and driving the driving ejector rod 5-6 to slide in a reciprocating manner along the length direction of the jacking chute;

the universal shafts 5-13 are arranged in the jacking sliding grooves, one ends of the universal shafts are hinged with the inner ends of the output nozzles 2-7, and the other ends of the universal shafts are hinged with one ends of the driving ejector rods 5-6.

In order to facilitate the cascade connection of a plurality of compound nozzles, the front end of the linking module 1 is provided with a female connecting groove 1-1 which is concave inwards, the rear end of the linking module is fixedly connected with a male connecting head 1-2 which protrudes outwards, and the male connecting head 1-2 and the linking module 1 are mutually spliced and matched for connection and adjacency.

Preferably, the outer shell A is cubic; the cross section of the nozzle A3-1 and the cross section of the nozzle B3-2 are both in inverted trapezoidal structures with large upper parts and small lower parts.

Preferably, the automatic printing machine further comprises a PLC controller, wherein the PLC controller is respectively connected with the first servo motor, the second servo motor, the first driving motor, the second driving motor, the nozzle A valve 3-4, the nozzle B valve 3-5 and the switching valve 3-9, so that 3D printing and synchronous anchor rod inserting operation can be conveniently and automatically realized.

The anchor rod implanting module and the extrusion nozzle module are respectively arranged on the left side and the right side of the linking module, and the anchor rod implanting module is internally provided with the top bottom anchor rod output device and the side part anchor rod output device, so that the top bottom anchor rod and the side part anchor rod can be effectively implanted in the 3D printing process in a synchronous mode, and the problems of obvious distortion phenomenon and low result accuracy in a similar physical simulation test in the prior art can be effectively solved. Through the cooperation setting that makes first interlock drive wheel and second interlock drive wheel, can be convenient pass through output nozzle with the stock and export to outside to be convenient for automatic completion anchor rod's the insertion process. Two swing shafts are fixedly connected to two opposite sides of the output nozzle, so that the output nozzle can have a certain swing amplitude in the first strip-shaped through hole or the second strip-shaped through hole. Through the relative cooperation setting of first lifting gear and second lifting gear, the reciprocating motion through the drive ejector pin that can be convenient drives the swing range of delivery nozzle one end to change delivery nozzle's that can be automatic inclination can realize the synchronous implantation of specific inclination stock. The nozzle can automatically and synchronously implant the scaled anchor bolt supporting member in the 3D printing process of similar physical models, can reduce the implantation difficulty of the supporting member, and can effectively reduce the labor intensity of operators.

The invention also provides a working method of the composite nozzle for 3D printing of the similar physical model, which comprises the following steps:

the method comprises the following steps: determining a proper reduction ratio based on the real geological model, and further determining the sizes of the upper implanted anchor rod 2-2 and the top and bottom implanted anchor rod 2-4; establishing a digital model of a similar physical model through a computer, splitting the model according to the model and the roadway condition, cutting and printing the left upper and the right upper of the roadway by taking a selected vertical line as a reference, and reasonably determining the printing sequence of each printing unit;

step two: exporting each printing unit into an stl format file, importing the stl format file into a 3D printer for slicing, and determining printing parameters;

step three: reasonably allocating cement-based materials according to the occurrence condition of an original model rock stratum, and determining the number of required composite nozzles according to the thickness of the model and the row spacing between supports, so that adjacent composite nozzles are connected by mutual insertion of the connecting male heads 1-2 and the linking module 1, and stable and reliable connection is ensured; a material pumping pipeline is connected through the changeover valve 3-9 and the flange 3-10; further determining whether to open the valve 3-4 of the nozzle A and the valve 3-5 of the nozzle B according to the thickness of the model;

step four: respectively placing top and bottom implanted anchor rods 2-4 and side implanted anchor rods 2-2 with the sizes reduced in proportion into an anchor rod storage barrel 2-3 and an anchor rod storage groove 2-1, respectively placing a first anchor rod in the anchor rod storage barrel 2-3 and the anchor rod storage groove 2-1 into output nozzles 2-7 of a top and bottom anchor rod output device 2-5 and a side anchor rod output device 2-6, starting a system and operating the top and bottom anchor rod output device 2-5 and the side anchor rod output device 2-6 to enable the exposed length of the anchor rod to be just contacted with the upper surface of the set printed layer, namely the upper surface of the previous printed layer 4-3; preferably, when the bolt discharging operation cannot be automatically performed, auxiliary adjustment can be performed manually so that the bolts in the bolt storage barrels 2-3 and the bolt storage grooves 2-1 can be smoothly loaded into the discharge nozzles 2-7 of the top-bottom bolt discharging device 2-5 and the upper bolt discharging device 2-6, respectively.

Step five: starting a 3D printer, printing a similar physical model 4 in a layer-by-layer accumulation mode, and distinguishing layers by an interlayer spacing line 4-1; sequentially forming the current printing layer 4-2 along with the forward movement of the composite nozzles, wherein printing units respectively formed by the single composite nozzle A3-1 and the nozzle B3-2 are distinguished by a gap separation trace 4-5, and adjacent composite nozzles are distinguished by a unit separation trace 4-6;

in the printing process, the first servo motor and the second servo motor are controlled to be started in real time according to the printing parameters set in the step two at the forming position of the roadway, so that the first meshing driving wheel 5-1 and the second meshing driving wheel 5-2 are driven to rotate oppositely, the anchor rod is inserted into the previous printing layer 4-3 by the top-bottom anchor rod output device 2-5 and the upper anchor rod output device 2-6, the inserting depth is in direct proportion to the number of rotation turns of the servo motors, the operation of the first servo motor and the operation of the second servo motor are repellent to the forward movement of the composite nozzle, the former operates, and the latter waits until the previous layer of implanted anchor rod 4-7 is formed; after the first servo motor and the second servo motor are stopped, the composite nozzle is controlled to move forwards continuously, the inserted previous layer of implanted anchor rod 4-7 passes through the nozzle gap 3-3 and is covered by materials extruded by the nozzle A3-1 and the nozzle B3-2, and the current layer of implanted anchor rod 4-4 is formed;

step six: after all the units are printed, maintaining for 10 days, assembling all the units similar to the physical model 4 to form a complete model, then installing a ladder beam and a steel belt with reduced sizes in a specific supporting area according to engineering conditions, enabling holes of the ladder beam and the steel belt to correspond to anchor rod positions, and then installing a tray; finally, selecting nuts with specific labels according to the parameters of the size-reduced anchor rods, and screwing the nuts to form an integral supporting system;

step seven: and continuing maintaining the completed 3D printing similar physical model, and carrying out subsequent test analysis work.

Preferably, in the second step, the printing parameters include information of a layer height, a printing speed, a bolting position and a bolting waiting time.

Preferably, in the third step, the valve 3-4 of the nozzle A and the valve 3-5 of the nozzle B are opened, so that the nozzle A3-1 and the nozzle B3-2 extrude at least materials with the height of not less than 20cm for the fluency test.

In order to improve the general range and print out similar physical models better, in the fifth step, in the anchor bolt support of the roadway side part, at a specific supporting position needing to be supported, controlling a nozzle A3-1 and a nozzle B3-2 to stop extruding materials by controlling a nozzle A valve 3-4 and a nozzle B valve 3-5 respectively, controlling an integral composite nozzle to lift upwards for 15mm, then idling to the far end of the model and rotating for 180 degrees, implanting an anchor bolt 2-2 to be implanted in the side part and a top-bottom implanted anchor bolt 2-4 to the side part, then descending the composite nozzle to the height needing to be supported by the anchor bolt, and finally returning to the supporting position needing to be supported; starting a first servo motor and a second servo motor to drive a first meshing driving wheel 5-1 and a second meshing driving wheel 5-2 to rotate, and inserting the anchor rod into the printed layer through a top anchor rod output device 2-5 and a bottom anchor rod output device 2-6; after the steps, the integral composite nozzle is idle to the far end of the model, rotates 180 degrees, then raises the composite nozzle to the printing height of the current layer, returns to the extrusion stopping position, and starts the subsequent printing process.

In order to realize the synchronous insertion of the inclined anchor rod and improve the universality, in the fifth step, when the inclined anchor rod needs to be implanted in the printing process, firstly, the injection position is controlled to control the nozzle A3-1 and the nozzle B3-2 to stop extruding materials, then, the first driving motor and the second driving motor are started according to the requirement of the inclined angle to synchronously drive the first lifting gear 5-9 and the second lifting gear 5-10 so as to drive the driving ejector rod 5-6 to ascend or descend for a set height, further, the universal shaft 5-13 drives the output nozzle 2-7 to ascend and descend around the swinging shaft 5-8 for a set angle which is in direct proportion to the number of rotation turns of the first driving motor and the second driving motor, and then, the first servo motor and the second servo motor are controlled to be started so as to push out the anchor rod through the first meshing driving wheel 5-1 and the second meshing driving wheel 5-2, inserting the anchor rod into a corresponding position and a corresponding depth; when the implantation of the inclined anchor rod is finished, the first driving motor and the second driving motor drive the first lifting gear 5-9 and the second lifting gear 5-10 to drive the driving ejector rod 5-6 to return to the original position, and the output nozzle 2-7 is reset to be in a horizontal or vertical state under the combined action of the first tension spring 5-5 and the second tension spring 5-7.

The method has simple steps and low implementation cost, can quickly and accurately realize the 3D printing construction of the similar physical model, and can synchronously implant the anchor bolt supporting member in the 3D printing process of the similar physical model, so that the implantation difficulty of the supporting member is greatly reduced, and the automation degree is improved. The method can also realize the implantation of the inclined anchor rod, is favorable for realizing the accurate reduction of the real model, and thus can provide a brand new means for the similar physical simulation technology of the mine.