Concrete gradient spraying device and method for single-layer lining

Abstract

The invention discloses a concrete gradient spraying device and method for a single-layer lining, and relates to the field of underground engineering construction equipment.The concrete gradient spraying device comprises supporting frames, a spiral feeder fixedly installed on the tops of the supporting frames, a motor arranged at the end of the spiral feeder and a belt transmission assembly, and the three supporting frames form a three-channel spiral conveying system; the output end of the motor and belt transmission assembly is fixedly connected with a screw rod in the screw feeder, and the screw feeder is arranged in an inclined state. Through the collaborative design of the three-channel spiral conveying system and the mixing mechanism, a reliable structural foundation is provided for gradient spraying of concrete, the conveying amount of materials of the inner layer, the transition layer and the outer layer can be accurately adjusted through the three independently-controlled spiral feeders, linear gradual change of the material flow is achieved through control over the rotating speed of a motor, and the material mixing efficiency is improved. And it is ensured that all layers of materials are mixed according to the design proportion, and the problem that precise matching of gradient materials cannot be achieved through traditional single-channel conveying is solved.

Description

Technical Field

[0001] This invention relates to the field of underground engineering construction equipment technology, specifically to a concrete gradient spraying device and method for single-layer lining. Background Technology

[0002] In the construction of underground projects such as tunnels and underground utility tunnels, single-layer lining, as a structure that is in direct contact with the surrounding rock and bears the load, directly determines the safety and durability of the project.

[0003] For example, in the publication CN116335716A, "A Gradient Shotcrete Structure for Single-Layer Lining of Tunnels and Its Construction Method", the shotcrete structure uses the surrounding rock surface of the tunnel as the base. The concrete structure includes, in sequence, a mixed steel fiber shotcrete layer, a water-retaining shotcrete mortar layer, and a low-shrinkage shotcrete layer. The mixed steel fiber shotcrete layer includes cementitious materials, mixed fibers, liquid early-strength agent, liquid alkali-free quick-setting agent, aggregates, and water. The water-retaining shotcrete mortar layer includes ordinary silicate cement, silica fume, fine aggregates, heavy calcium carbonate powder, liquid water-reducing agent, water-retaining modifier, and liquid alkali-free quick-setting agent. The low-shrinkage shotcrete layer includes cementitious materials, shrinkage-reducing agent, liquid water-reducing agent, liquid alkali-free quick-setting agent, and aggregates.

[0004] However, in existing technologies, concrete spraying technology mostly uses single-performance concrete for spraying, which is difficult to meet the gradient performance requirements of lining in terms of impermeability, strength, and crack resistance. First, the single-channel material conveying system cannot accurately control the proportion of materials with different performance characteristics, resulting in uneven transition of gradient performance. Second, there is a lack of intelligent monitoring and dynamic control mechanisms, resulting in large deviations in spraying thickness, often exceeding 10mm. Third, the construction process requires material replacement midway, the single-cycle spraying time is long, the efficiency is low, and there is serious material waste, resulting in high overall project costs. Summary of the Invention

[0005] The purpose of this invention is to provide a concrete gradient spraying device and method for single-layer lining, so as to solve the problem of uneven gradient performance transition caused by the inability of single-channel material conveying system to accurately control the proportion of materials with different properties.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a concrete gradient spraying device for single-layer lining, comprising a support frame and a screw feeder fixedly installed on its top, a motor and belt drive assembly disposed at the end of the screw feeder, the three support frames forming a three-channel screw conveying system, the output end of the motor and belt drive assembly being fixedly connected to the screw rod inside the screw feeder, the screw feeder being arranged in an inclined state, the discharge end of the screw feeder being connected to a conveying pipe, and the end of the conveying pipe being connected to a mixing mechanism;

[0007] The mixing mechanism includes a base, a receiving cylinder, and a spray pipe. A connecting pipe is fixedly installed on the top of the base, and a feeding hopper is connected to the bottom of the receiving cylinder. The feeding hopper and the connecting pipe are connected through a gooseneck pipe. A servo motor is fixedly installed on the inner side of the base, and a mixing fan is fixedly connected to the output end of the servo motor. The mixing fan is located inside the connecting pipe, and a feeding groove is opened inside the connecting pipe. The spray pipe is connected to the feeding groove.

[0008] Preferably, a vibrating motor is fixedly installed on the outer wall of the hopper, and positioning blocks are fixedly installed at the four equal division points of the edge of the hopper. A support seat corresponding to the position of the positioning block is fixedly installed on the upper surface of the base. A guide rod is inserted vertically inside the support seat and the guide rod is engaged with the inner side of the positioning block.

[0009] Preferably, the base has two opposite sides fixedly installed on its upper surface, and the end is fixedly installed. The edge of the connecting pipe is sleeved on the outer wall, and the edge of the connecting pipe is connected to a secondary pipe, which is located on the side of the mixing fan.

[0010] A method for using a concrete gradient spraying device for single-layer lining, in conjunction with a control system, is disclosed. This system includes a material supply module, a mix proportioning module, a spraying execution module, a parameter monitoring module, a control center module, and auxiliary function modules. The material supply module controls the support frame to provide stable and qualified substrate and admixtures for the entire spraying process. The mix proportioning module controls the mixing fan to mix concrete materials according to the designed ratio. The spraying execution module controls the spray pipe to spray qualified concrete to designated locations. The parameter monitoring module tracks key parameters during the spraying process in real time. The control center module coordinates the collaborative work of each module. The auxiliary function modules monitor the operating status of the device. The method of use includes the following steps:

[0011] Step 1: Cleaning and setting parameters of the surrounding rock surface: Remove scum, dust, loose rocks and other debris from the surface. After cleaning the surrounding rock surface, install thickness positioning guide lines on the surrounding rock surface according to the designed lining thickness requirements. The guide lines are made of nylon rope and are fixed to the surrounding rock with expansion bolts as a reference for subsequent spraying thickness.

[0012] The second step is to set the mix ratio and spraying process parameters of each layer of concrete through the control center module. Input the mix ratio parameters and spraying process parameters of each layer of concrete on the touch screen. In the initial stage of spraying, the inner layer material is sprayed first. The control center module gradually adjusts the flow rate of the transition layer material by linearly increasing the speed of the screw feeder and the frequency of the metering pump corresponding to the transition layer, while keeping the flow rate of the inner layer material stable. Then, the conveying of the outer layer material is started.

[0013] The third step involves the control center module using the screw feeder of the three-channel screw conveying system to transport the base material through the conveying pipe to the conveying and mixing mechanism. At the same time, the metering pump of the material supply module delivers the corresponding additives through the auxiliary pipe to the conveying and unloading hopper according to the set ratio. After the materials are combined in the unloading hopper, the servo motor drives the mixing fan to stir and mix them.

[0014] The fourth step is laser scanning monitoring and dynamic adjustment. The spray pipe is installed on the robotic arm, and a laser scanner is mounted on its pipe to acquire the three-dimensional contour data of the spray surface. The laser scanner transmits the scan data to the control center module.

[0015] Preferably, the material supply module includes a substrate storage submodule, an admixture storage submodule, and a conveying pipeline submodule. It consists of a three-channel spiral conveying system composed of three spiral feeders, forming three independent silos for the inner layer, transition layer, and outer layer materials. The admixture storage submodule is equipped with a dedicated storage tank for different admixtures, which is connected to the secondary pipe. The addition amount of the storage tank is controlled by a metering pump. The conveying pipeline submodule controls the spray pipe and the secondary pipe. Both the spray pipe and the secondary pipe are equipped with solenoid valves, pressure sensors, and flow guiding devices.

[0016] Preferably, the proportioning control module includes a proportioning calculation submodule, a precise metering submodule, and a mixing submodule. The proportioning calculation submodule has a built-in multi-layer proportioning database, receives real-time flow data from the material supply module, and calculates the adjustment amount of each material.

[0017] Preferably, the spraying execution module includes a spraying robotic arm submodule, a nozzle assembly submodule, and a layered spraying control submodule. The spraying robotic arm submodule adopts a 6-DOF robotic arm, equipped with a servo drive system, and has a rotary joint at the end to control the robotic arm. The nozzle assembly submodule is made of wear-resistant alloy material. The layered spraying control submodule combines a position sensor, a laser rangefinder, and real-time thickness monitoring based on laser scanning to form intelligent thickness control, monitoring the spraying position and thickness.

[0018] Preferably, the parameter monitoring module includes a pressure monitoring submodule, a speed monitoring submodule, a time monitoring submodule, and a quality detection submodule, which respectively monitor the pressure, speed, concrete setting time, and spraying quality during the spraying process. The control center module includes a central control submodule, a human-machine interaction submodule, and a data management submodule. The central control submodule uses a PLC to achieve automatic control and fault self-diagnosis. The human-machine interaction submodule is equipped with a touch screen to support parameter setting and status viewing.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. In this invention, the collaborative design of a three-channel spiral conveying system and a mixing mechanism provides a reliable structural foundation for gradient concrete spraying. The three independently controlled spiral feeders can precisely adjust the conveying volume of the inner, transition, and outer layers of materials. The linear gradual change of material flow rate is achieved through motor speed control, ensuring that the materials of each layer are mixed according to the design ratio. This solves the problem that traditional single-channel conveying cannot achieve precise proportioning of gradient materials. In the mixing mechanism, the cooperation between the vibrating motor, positioning block, and guide rod effectively avoids material blockage and equipment deviation. The flexible connection design of the gooseneck pipe reduces the impact during material conveying. The structural layout of the mixing fan and connecting pipe ensures the uniformity of material mixing. The design of the auxiliary pipe for connecting admixtures further enhances the flexibility of concrete performance adjustment. In addition, the sleeve structure of the connecting pipe and related components of the base enhances the stability of equipment operation. The overall structural design makes the material transition of gradient spraying smoother, providing a uniform and continuous performance gradient for single-layer lining, and significantly improving the integrity and reliability of the lining structure.

[0021] 2. In this invention, the multi-module control system of the device realizes intelligent control of the entire spraying process, which greatly improves construction efficiency and quality. The material supply module ensures a stable supply of base material and admixtures in proportion through precise metering and independent silo design. The proportion control module dynamically adjusts the material proportion according to environmental factors by means of proportion calculation and real-time correction function. The 6-DOF robotic arm and laser scanning monitoring system of the spraying execution module can compare the design contour in real time and dynamically adjust the nozzle trajectory and spraying parameters. The human-machine interaction and data management functions of the control center module realize the visualization setting of parameters and the traceability of data throughout the process. Combined with the safety protection and environmental adaptability of the auxiliary function module, the stable operation of the equipment under complex working conditions is guaranteed.

[0022] 3. In this invention, the performance advantages of gradient materials are fully utilized through a layered spraying and dynamic control strategy. In the initial stage of construction, the inner layer material is sprayed first to form a bonding layer, and then the transition layer and the outer layer material are smoothly connected through gradual flow control. With the help of a laser scanner for real-time adjustment, the lining is ensured to exhibit a gradient in compressive strength and impermeability grade in the thickness direction. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a concrete gradient spraying device for single-layer lining according to the present invention.

[0024] Figure 2 This is a schematic diagram of the connection and structure of the conveying pipeline and mixing mechanism of a concrete gradient spraying device for single-layer lining according to the present invention.

[0025] Figure 3 This is a three-dimensional structural diagram of the mixing mechanism of a concrete gradient spraying device for single-layer lining according to the present invention.

[0026] Figure 4 This is a schematic diagram of the internal structure of the connecting pipe of a concrete gradient spraying device for single-layer lining according to the present invention.

[0027] Figure 5 This is a block diagram of the control system in a concrete gradient spraying device for single-layer lining according to the present invention.

[0028] In the diagram: 1. Support frame; 2. Screw feeder; 3. Motor and belt drive assembly; 4. Conveying pipe; 5. Mixing mechanism; 51. Base; 52. Receiving cylinder; 53. Spraying pipe; 54. Discharge hopper; 55. Connecting pipe; 56. Vibrating motor; 57. Positioning block; 58. Support seat; 59. Guide rod; 510. Mixing fan; 511. Discharge chute; 512. Secondary pipe; 513. Limiting rod; 514. Baffle plate. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1: Refer to Figure 1 , Figure 2 , Figure 3 and Figure 4As shown: A concrete gradient spraying device for single-layer lining includes a support frame 1 and a screw feeder 2 fixedly installed on its top, a motor and belt drive assembly 3 located at the end of the screw feeder 2. The three support frames 1 form a three-channel screw conveying system. The output end of the motor and belt drive assembly 3 is fixedly connected to the screw rod inside the screw feeder 2. The screw feeder 2 is arranged in an inclined state. The discharge end of the screw feeder 2 is connected to a conveying pipe 4. The end of the conveying pipe 4 is connected to a mixing mechanism 5. The mixing mechanism 5 includes a base 51, a receiving cylinder 52, and a spraying pipe 53. A connecting pipe 55 is fixedly installed on the top of the base 51. A discharge hopper 54 is connected to the bottom of the receiving cylinder 52. The discharge hopper 54 and the connecting pipe 55 are connected through a gooseneck pipe. A servo motor is fixedly installed on the inner side of the base 51. The output end of the servo motor is fixedly connected to the mixing mechanism 53. The material fan 510 and mixing fan 510 are located inside the connecting pipe 55. The connecting pipe 55 has a discharge trough 511 inside. The spray pipe 53 is connected to the discharge trough 511. A vibration motor 56 is fixedly installed on the outer wall of the discharge hopper 54. A positioning block 57 is fixedly installed at the four equal division points at the edge of the discharge hopper 54. A support seat 58 corresponding to the position of the positioning block 57 is fixedly installed on the upper surface of the base 51. A guide rod 59 is inserted vertically inside the support seat 58. The guide rod 59 is snapped into the inner side of the positioning block 57. A baffle plate 514 is fixedly installed on both opposite sides of the upper surface of the base 51. A limit rod 513 is fixedly installed at the end of the baffle plate 514. The edge of the connecting pipe 55 is sleeved on the outer wall of the limit rod 513. A secondary pipe 512 is connected to the edge of the connecting pipe 55. The secondary pipe 512 is located on the side of the mixing fan 510.

[0031] In this embodiment, the three-channel spiral conveying system composed of three support frames 1 is the core of material conveying. The motor and belt drive assembly 3 provides power to the spiral feeder 2, and its output end is fixedly connected to the spiral rod inside the spiral feeder 2. When the motor starts, the spiral rod rotates accordingly, pushing the concrete materials in different hoppers corresponding to the inner layer, transition layer, and outer layer gradient materials along the inclined spiral feeder 2 to the discharge end. Since the three spiral feeders 2 are independently controlled, the conveying amount of different materials can be precisely controlled by adjusting the speed of their respective motors, so as to achieve gradient spraying. Laying the foundation, the discharge end of the screw feeder 2 conveys the material to the mixing mechanism 5 through the conveying pipe 4. In the mixing mechanism 5, the receiving cylinder 52 receives the conveyed material, which falls through the bottom-connected hopper 54. When the vibrating motor 56 on the outer wall of the hopper 54 is working, it generates vibration, which can effectively prevent the material from clogging during the falling process and ensure smooth discharge. The positioning block 57 on the edge of the hopper 54 cooperates with the guide rod 59 in the support seat 58 on the upper surface of the base 51. The guide rod 59 is engaged inside the positioning block 57. When the vibrating motor 56 is working, it facilitates the discharge of the hopper 54. 4. Provides stable support and vibration guidance to prevent the hopper 54 from shifting due to vibration. The hopper 54 conveys the material to the connecting pipe 55 at the top of the base 51 through the gooseneck tube. The servo motor inside the base 51 drives the mixing fan 510 to rotate. The mixing fan 510 is located inside the connecting pipe 55. When the material enters the connecting pipe 55, the mixing fan 510 stirs and mixes it. The discharge trough 511 inside the connecting pipe 55 provides a conveying channel for the mixed material. Finally, the material is sprayed out through the spray pipe 53 connected to the discharge trough 511, completing the spraying operation. In addition, the connecting pipe 510... The secondary pipe 512 at the edge of the connecting pipe 55 is located on the side of the mixing fan 510. It can be connected to admixtures or other auxiliary materials. Under the stirring action of the mixing fan 510, it is fully mixed with the main material to further adjust the concrete performance and meet the differentiated requirements of gradient spraying for material performance. At the same time, the edge of the connecting pipe 55 is sleeved on the outer wall of the relevant components on the base 51, which ensures the stability of the connecting pipe 55 during operation and ensures the smooth progress of material mixing and conveying. When used in conjunction with the baffle plate 514 and the limiting rod 513, the stability of the connecting pipe 55 can be guaranteed.

[0032] Example 2: A method of using a concrete gradient spraying device for single-layer lining, also using a control system. This system includes a material supply module, a mix proportioning module, a spraying execution module, a parameter monitoring module, a control center module, and auxiliary function modules. The material supply module controls the support frame 1 to provide stable and qualified substrate and admixtures for the entire spraying process. The mix proportioning module controls the mixing fan 510 to mix concrete materials according to the design ratio. The spraying execution module controls the spray pipe 53 to spray qualified concrete to the designated location. The parameter monitoring module tracks key parameters during the spraying process in real time. The control center module coordinates the collaborative work of each module. The auxiliary function modules detect the operating status of the device. The method of use includes the following steps:

[0033] Step 1: Cleaning and setting parameters of the surrounding rock surface: Remove scum, dust, loose rocks and other debris from the surface. After cleaning the surrounding rock surface, install thickness positioning guide lines on the surrounding rock surface according to the designed lining thickness requirements. The guide lines are made of nylon rope and are fixed to the surrounding rock with expansion bolts as a reference for subsequent spraying thickness.

[0034] The second step involves setting the mix proportions and spraying process parameters for each concrete layer via the control center module. The mix proportions and spraying process parameters for each layer are input on the touchscreen. In the initial spraying stage, the inner layer material is sprayed first, with an initial flow rate set to 8–10 m³ / h to ensure rapid coverage of the surrounding rock surface and formation of an initial bonding layer. As the inner layer material reaches 30%–40% of the designed thickness, the control center module gradually adjusts the flow rate of the transition layer material. This is achieved by linearly increasing the rotational speed of the screw conveyor 2 and the frequency of the metering pump corresponding to the transition layer, gradually increasing the flow rate from 0 m³ / h to 6–8 m³ / h while maintaining a stable flow rate for the inner layer material. When the inner layer material reaches 70%–80% of the designed thickness, the outer layer material is started, following the same control logic as the transition layer, gradually increasing the flow rate from 0 m³ / h to 4–6 m³ / h.

[0035] The third step is that the control center module uses the screw feeder 2 of the three-channel screw conveying system to transport the base material through the conveying pipe 4 to the conveying and mixing mechanism 5. At the same time, the metering pump of the material supply module delivers the corresponding additives through the auxiliary pipe 512 to the conveying and unloading hopper 54 according to the set ratio. After the materials are combined in the unloading hopper 54, the servo motor drives the mixing fan 510 to stir and mix.

[0036] Step 4: Laser scanning monitoring and dynamic adjustment. The spray pipe 53 is mounted on the robotic arm, and a laser scanner is also mounted on its pipe. The scanning frequency is 10-15 times / second to acquire the three-dimensional contour data of the spray surface. The laser scanner transmits the scanned data to the control center module. The control center module compares this data with the preset design contour and calculates the deviation between the actual spray surface and the design contour. After calculating the deviation, if the actual spray thickness is less than the design thickness, the pressure monitoring submodule of the central control submodule of the control center module increases the spray pressure while reducing the moving speed of the spray robotic arm submodule to increase the amount of material sprayed per unit area. When the actual spray thickness is greater than the design thickness, the spray pressure is reduced and the robotic arm moving speed is increased to reduce the amount of material sprayed. After scanning and discovering a positional deviation between the spray position and the design contour, the central control submodule instructs the spraying robotic arm submodule to adjust its motion trajectory. By controlling the rotation angle of each joint of the robotic arm submodule, the spraying center of the nozzle assembly submodule is aligned with the design trajectory. Based on the thickness deviation, the central control submodule instructs the proportioning calculation submodule of the proportioning control module to recalculate the material proportions. The recalculation of the material proportions by the proportioning control module includes the following steps: when a local area needs to increase strength, the proportion of cement and high-efficiency water-reducing agent in the corresponding outer layer material is increased; when it is necessary to improve impermeability, the proportion of waterproofing agent in the inner layer material is increased. The proportioning calculation submodule transmits the new proportioning parameters to the precision metering submodule, which adjusts the speed of the screw conveyor and the frequency of the metering pump in the corresponding silo.

[0037] Example 3: Refer to Figure 5 As shown, a control system includes a material supply module comprising a substrate storage submodule, an admixture storage submodule, and a conveying pipeline submodule. It consists of a three-channel screw conveying system composed of three screw feeders 2. The substrate storage submodule is a support frame 1 with multiple independent sealed silos storing cement, coarse aggregates of different particle sizes, and medium sand, respectively. These are three independent silos for the inner layer, transition layer, and outer layer materials. The admixture storage submodule has dedicated storage tanks for different admixtures, connected to a secondary pipe 512. The conveying pipeline submodule uses wear-resistant and corrosion-resistant pipelines. The storage tanks are corrosion-resistant and equipped with level gauges and temperature sensors. The addition amount is controlled by a metering pump. The conveying pipeline submodule controls the spray pipe 53 and the secondary pipe 512, using independent wear-resistant and corrosion-resistant pipelines to convey the substrate and admixtures. Both the spray pipe 53 and the secondary pipe 512 are equipped with solenoid valves, pressure sensors, and flow guiding devices.

[0038] The proportioning control module includes a proportioning calculation submodule, a precision metering submodule, and a mixing submodule. The proportioning calculation submodule has a built-in multi-layer proportioning database, receives real-time flow data from the material supply module and calculates the adjustment amount of each material, and automatically corrects the proportioning parameters according to the ambient temperature and humidity. The precision metering submodule installs high-precision flow meters on the conveying pipe 4 and the auxiliary pipe 512, and adjusts the speed of the screw feeder 2 and the frequency of the metering pump. The mixing submodule controls the screw feeder 2, which is equipped with a humidity sensor and a uniformity detector.

[0039] The spraying execution module includes a spraying robotic arm submodule, a nozzle assembly submodule, and a layered spraying control submodule. The spraying robotic arm submodule uses a 6-DOF robotic arm equipped with a servo drive system, and a rotary joint is installed at the end to control the robotic arm. The nozzle assembly submodule is made of wear-resistant alloy material, with an adjustable outlet diameter. It has a guide plate and a built-in material mixer to achieve gradient transition, and connects to compressed air pipes and water pipes and is controlled by a proportional valve. The layered spraying control submodule combines a position sensor, a laser rangefinder, and real-time thickness monitoring based on laser scanning to form intelligent thickness control. It monitors the spraying position and thickness, provides feedback to adjust the spraying pressure and the robotic arm's movement speed, and controls the spraying switching.

[0040] The parameter monitoring module includes a pressure monitoring submodule, a speed monitoring submodule, a time monitoring submodule, and a quality inspection submodule, which respectively monitor the pressure, speed, concrete setting time, and spraying quality during the spraying process. The control center module includes a central control submodule, a human-machine interface submodule, and a data management submodule. The central control submodule uses a PLC to achieve automatic control and fault self-diagnosis; the human-machine interface submodule is equipped with a touch screen to support parameter setting and status viewing; and the data management submodule stores spraying data and enables remote transmission.

[0041] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A concrete gradient spraying device for single-layer lining, characterized in that: The system includes a support frame (1) and a screw feeder (2) fixedly installed on its top, and a motor and belt drive assembly (3) set at the end of the screw feeder (2). The three support frames (1) form a three-channel screw conveying system. The output end of the motor and belt drive assembly (3) is fixedly connected to the screw rod inside the screw feeder (2). The screw feeder (2) is arranged in an inclined state. The discharge end of the screw feeder (2) is connected to a conveying pipe (4). The end of the conveying pipe (4) is connected to a mixing mechanism (5). The mixing mechanism (5) includes a base (51), a receiving cylinder (52), and a spray pipe (53). A connecting pipe (55) is fixedly installed on the top of the base (51). A feeding hopper (54) is connected to the bottom of the receiving cylinder (52). The feeding hopper (54) and the connecting pipe (55) are connected through a gooseneck pipe. A servo motor is fixedly installed on the inner side of the base (51). A mixing fan (510) is fixedly connected to the output end of the servo motor. The mixing fan (510) is located inside the connecting pipe (55). A feeding groove (511) is opened inside the connecting pipe (55). The spray pipe (53) is connected to the feeding groove (511).

2. The concrete gradient spraying device for single-layer lining according to claim 1, characterized in that: A vibration motor (56) is fixedly installed on the outer wall of the hopper (54). A positioning block (57) is fixedly installed at the four equal division points at the edge of the hopper (54). A support seat (58) corresponding to the position of the positioning block (57) is fixedly installed on the upper surface of the base (51). A guide rod (59) is inserted vertically inside the support seat (58). The guide rod (59) is snapped into the inner side of the positioning block (57).

3. A concrete gradient spraying device for single-layer lining according to claim 2, characterized in that: A baffle plate (514) is fixedly installed on both opposite sides of the upper surface of the base (51). A limit rod (513) is fixedly installed at the end of the baffle plate (514). The edge of the connecting pipe (55) is sleeved on the outer wall of the limit rod (513). A secondary pipe (512) is connected to the edge of the connecting pipe (55). The secondary pipe (512) is located on the side of the mixing fan (510).

4. A method of using a concrete gradient spraying device for single-layer lining, characterized in that, A concrete gradient spraying device for single-layer lining as described in any one of claims 1-3 is used, and a control system is also used. This system includes a material supply module, a proportioning control module, a spraying execution module, a parameter monitoring module, a control center module, and an auxiliary function module. The material supply module controls the support frame (1) to provide stable and qualified substrate and admixtures for the entire spraying process. The proportioning control module controls the mixing fan (510) to mix concrete materials according to the design ratio. The spraying execution module controls the spray pipe (53) to spray qualified concrete to a designated location. The parameter monitoring module tracks key parameters during the spraying process in real time. The control center module coordinates the collaborative work of each module. The auxiliary function module detects the operating status of the device. The method of use includes the following steps: S1. Cleaning and parameter setting of surrounding rock surface: Remove scum, dust, loose rocks and other debris from the surface. After cleaning the surrounding rock surface, install thickness positioning guide lines on the surrounding rock surface according to the designed lining thickness requirements. The guide lines are made of nylon rope and are fixed to the surrounding rock with expansion bolts as a reference for subsequent spraying thickness. S2. Set the mix ratio and spraying process parameters of each layer of concrete through the control center module. Input the mix ratio parameters and spraying process parameters of each layer of concrete on the touch screen. In the initial stage of spraying, prioritize spraying the inner layer material. The control center module gradually adjusts the flow rate of the transition layer material by linearly increasing the speed of the screw feeder (2) and the frequency of the metering pump corresponding to the transition layer, while keeping the flow rate of the inner layer material stable. Then start the conveying of the outer layer material. S3. The control center module uses the screw feeder (2) of the three-channel screw conveying system to transport the base material through the conveying pipe (4) to the conveying and mixing mechanism (5). At the same time, the metering pump of the material supply module delivers the corresponding additives through the auxiliary pipe (512) to the conveying and unloading hopper (54) according to the set ratio. After the materials are combined in the unloading hopper (54), the servo motor drives the mixing fan (510) to stir and mix. S4. Laser scanning monitoring and dynamic adjustment: The spray pipe (53) is installed on the robotic arm, and a laser scanner is mounted on its pipe to obtain the three-dimensional contour data of the spray surface. The laser scanner transmits the scan data to the control center module.

5. The method of using a concrete gradient spraying device for single-layer lining according to claim 4, characterized in that: The material supply module includes a substrate storage submodule, an admixture storage submodule, and a conveying pipeline submodule. It consists of a three-channel spiral conveying system composed of three spiral feeders (2), which are three independent silos for the inner layer, transition layer, and outer layer materials. The admixture storage submodule is equipped with a dedicated storage tank for different admixtures, which is connected to the secondary pipe (512). The storage tank is controlled by a metering pump to control the addition amount. The conveying pipeline submodule controls the spray pipe (53) and the secondary pipe (512). Both the spray pipe (53) and the secondary pipe (512) are equipped with solenoid valves, pressure sensors, and flow guiding devices.

6. The method of using a concrete gradient spraying device for single-layer lining according to claim 5, characterized in that: The proportioning control module includes a proportioning calculation submodule, a precise metering submodule, and a mixing submodule. The proportioning calculation submodule has a built-in multi-layer proportioning database, receives real-time flow data from the material supply module, and calculates the adjustment amount of each material.

7. The method of using a concrete gradient spraying device for single-layer lining according to claim 6, characterized in that: The spraying execution module includes a spraying robotic arm submodule, a nozzle assembly submodule, and a layered spraying control submodule. The spraying robotic arm submodule adopts a 6-DOF robotic arm equipped with a servo drive system and a rotary joint at the end to control the robotic arm. The nozzle assembly submodule is made of wear-resistant alloy material. The layered spraying control submodule combines a position sensor, a laser rangefinder, and real-time thickness monitoring based on laser scanning to form intelligent thickness control, monitoring the spraying position and thickness.

8. The method of using a concrete gradient spraying device for single-layer lining according to claim 7, characterized in that: The parameter monitoring module includes a pressure monitoring submodule, a speed monitoring submodule, a time monitoring submodule, and a quality detection submodule, which respectively monitor the pressure, speed, concrete setting time, and spraying quality during the spraying process. The control center module includes a central control submodule, a human-machine interaction submodule, and a data management submodule. The central control submodule uses a PLC to achieve automatic control and fault self-diagnosis. The human-machine interaction submodule is equipped with a touch screen.

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