Method and device for detecting gas in small-section tunnel excavated by single-cantilever heading machine

Abstract

The invention discloses a gas detection method and device for a small-section tunnel excavated by a single-cantilever heading machine. According to the invention, the optical detection device is integrated on the single-cantilever heading machine, and dynamic multi-point scanning is adopted, so that comprehensive coverage monitoring of the gas concentration is realized. The method comprises the steps of tunneling sampling, air detection, detection result conversion and detection result visual display. By optimizing the anti-interference design of optical detection equipment, the reliability of the optical detection equipment in complex construction environments such as high dust concentration is enhanced; and meanwhile, a highly integrated design is adopted, so that the gas detection device can cooperatively operate with tunneling equipment. Compared with the prior art, the system has the advantages of being high in real-time performance, wide in coverage range, high in anti-interference capability and high in integration level, the problems that in the prior art, the detection range is limited in a complex environment, and the real-time performance is insufficient are effectively solved, and construction safety and efficiency are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of optical detection, and in particular to a gas detection method for a small-section tunnel excavated by a single-cantilever tunneling machine. Background Art

[0002] With the continuous expansion of underground engineering construction, the demand for operations in complex environments, including tunnel excavation, underground mining operations, and small-section tunnel excavation, has become increasingly demanding in terms of construction safety. Among them, the monitoring and analysis of gas concentration is a key link in the safety control of underground engineering. As a flammable and explosive gas, gas may cause major safety accidents such as fires and explosions when its concentration exceeds a certain threshold. Therefore, real-time, efficient, and accurate gas concentration monitoring technology is crucial to the safety of underground construction environments.

[0003] Traditional gas detection technologies are mostly based on chemical reaction sensors or electrochemical sensors. Although they are low-cost, they often show problems of insufficient sensitivity and greater interference in complex environments (small-section tunnels with high dust concentration and complex gas composition). In addition, such technologies often require close contact or pretreatment of gas samples, and cannot achieve non-contact, high-sensitivity monitoring of gas distribution over a large area;

[0004] In recent years, with the development of optical measurement technology, the method of gas detection using optical means has gradually attracted attention. Optical detection technology, with its high sensitivity and non-contact detection characteristics, overcomes many limitations of traditional detection methods and is particularly suitable for the field of gas detection.

[0005] As disclosed in the Chinese patent (publication number: CN205719964U), the handheld laser gas detection device comprises: a signal generating circuit configured to generate a measurement signal for driving a laser transmitter; the laser transmitter configured to emit a laser beam in response to the measurement signal; a reflected light receiver configured to receive a reflected laser beam; and a signal analyzing circuit configured to analyze the reflected laser beam to obtain a gas detection result;

[0006] However, in actual use, traditional optical detection technology still has certain limitations: such as limited detection range, insufficient real-time performance, insufficient anti-interference ability, and insufficient equipment integration. It is difficult to achieve centralized coordination between tunneling equipment and optical detection devices. For this reason, we propose a gas detection method and device for small-section tunnel excavation by a single-cantilever tunnel boring machine to solve the above problems. Summary of the invention

[0007] The purpose of the present invention is to provide a method and device for detecting gas in a small-section tunnel excavated by a single-cantilever tunnel boring machine, which has the advantages of optical detection with strong real-time performance, wide monitoring range and high integration of construction equipment, and solves the problems of existing gas detection technology in complex environments, such as limited detection range, insufficient real-time performance and difficulty in efficient cooperation with tunneling equipment.

[0008] To achieve the above object, the present invention provides the following technical solution: a method for detecting gas in a small-section tunnel excavated by a single-arm tunnel boring machine, comprising the following steps:

[0009] S1. Excavation sampling: As the rotating shaft carries the drill bit in the process of excavating a small section of the tunnel, the air in the tunnel during the excavation process is filtered and extracted through the sampling module;

[0010] Through the coordinated rotation of the rotating shaft and the cover, all-round extraction of tunnel air is achieved to avoid detection blind areas;

[0011] S2. Air detection: The air after filtering out the particle interference is optically detected in the detection tube;

[0012] S3, detection result conversion: the infrared sensor in the piston cylinder sends out a detection signal, and then the current transmitter converts the detection signal into an electrical signal output; the current transmitter is connected to the signal conditioning module, and the signal conditioning module conditions the electrical signal and transmits it to the signal conditioning circuit;

[0013] S4. Visual display of test results: The test results are judged by the brightness changes and flickering changes of the LED light board electrically connected to the conditioning circuit.

[0014] A gas detection device for excavating a small-section tunnel with a single-arm tunnel boring machine, comprising a shell arranged on the main body of the single-arm tunnel boring machine and a rotating shaft rotating on a fixed axis in the shell, the rotating shaft having an end away from the shell being fixedly connected to a drill bit for excavating a small-section tunnel, characterized in that: a cover body is rotatably connected to the shell with a fixed axis and is coaxially connected to the rotating shaft, a gear 1 is fixedly sleeved on an arc-shaped contour of an end of the rotating shaft away from the drill bit, a gear ring is fixedly connected to the end of the shell facing the drill bit, a gear 2 is transmission-engaged between the gear 1 and the gear ring, a driven shaft is coaxially fixedly connected to the inner wall of the gear 2, the driven shaft passes through and is rotatably connected to a detection cylinder, and the driven shaft passes through the cover body and is rotatably connected to the cover body on a fixed axis.

[0015] Preferably, one end of the detection tube away from the shell is fixed on the cover body, and an infrared sensor for detecting gas components in the air is provided in the detection tube. The infrared sensor is electrically connected in sequence to the current transmitter, the signal conditioning module and the signal conditioning circuit.

[0016] Preferably, the cover body is also provided with a sampling module for extracting air from the excavation environment, the sampling module includes a piston cylinder, the piston cylinder passes through and is fixed on the cover body, the inner wall of the piston cylinder is axially limited and slidably connected with a piston plate, an L-shaped transmission rod is fixedly connected to the side of the piston plate away from the outer shell, an inclined annular groove is provided on the arc profile of the driven shaft, one end of the L-shaped transmission rod away from the piston plate extends into the inclined annular groove and is slidably connected to the inner wall of the inclined annular groove, an intake pipe and an exhaust pipe are passed through and fixedly connected on the arc profile of the piston cylinder, the intake pipe and the exhaust pipe are centrally symmetrical with respect to the central axis of the piston cylinder, one end of the exhaust pipe away from the piston cylinder passes through a detection cylinder and extends into the detection cylinder, a one-way intake valve is fixedly connected to each of the intake pipe and the exhaust pipe, and a filter screen for filtering the sampled air is fixedly connected to the inner wall of the intake pipe, and a through hole for discharging the detected air is provided on the end of the detection cylinder away from the L-shaped transmission rod.

[0017] Preferably, an LED light panel for displaying the detection results is provided on the arc-shaped contour of the shell.

[0018] Preferably, a connecting tube is fixedly connected to the arc-shaped contour of the cover body, the LED light board is fixedly connected to the surface of the connecting tube, the end of the connecting tube away from the outer shell is fixedly connected to an electromagnet assembly electrically connected to a conditioning circuit, two metal semi-cylinders that are magnetically matched with the electromagnet assembly are axially limited and slidably connected in the connecting tube, a locking rebound cylinder that is axially slidably connected in the connecting tube is provided on the side of the metal semi-cylinder away from the electromagnet assembly, a support rod is fixedly connected to the side of the locking rebound cylinder away from the metal semi-cylinder, a pressure-sensitive switch that electrically connects the conditioning circuit to the LED light board is fixedly connected to the end of the support rod away from the locking rebound cylinder, a bottom cylinder fixed to the inner wall of the connecting tube is movably connected to the side of the pressure-sensitive switch away from the support rod, and a locking assembly that keeps the locking rebound cylinder away from the bottom cylinder is provided on the metal semi-cylinder.

[0019] Preferably, a return spring is fixedly connected between the bottom cylinder and the locking rebound cylinder to keep the pressure-sensitive switch in continuous contact with the surface of the bottom cylinder.

[0020] Preferably, the locking assembly includes two locking arms which are rotatably connected between two metal semi-cylinders on a fixed axis, a locking head which is fixedly connected to the side of the locking rebound cylinder facing the metal semi-cylinder and is locked with the two locking arms at the same time, the opposite surfaces of the two locking arms are fixedly connected to pressure rods, the opposite ends of the two pressure rods are fixedly connected to pressure blocks, the opposite surfaces of the two pressure blocks are fixedly connected to the same compression spring in a compressed state, the ends of the two locking arms facing the locking heads are both arc-shaped surfaces which are adapted to the locking heads, and a guide hole is provided at the center of the circle of the electromagnet assembly to guide the deflection of the ends of the two locking arms away from the locking rebound cylinder.

[0021] Preferably, the opposite surfaces of the two metal semi-cylinders on the side away from the locking rebound cylinder are fixedly connected with the same insertion rod, the inner wall of the guide hole is fixedly connected with two symmetrical connecting strips, and the opposite surfaces of the two connecting strips are fixedly connected with a limiting ring which is axially penetrated by the insertion rod and slidably connected.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention realizes full coverage monitoring of gas concentration in the excavation area by setting up a dynamic multi-point scanning optical detection system, eliminating the monitoring blind spots that may exist in traditional optical detection devices in complex environments;

[0024] 2. By optimizing the anti-interference design of the optical detection device, the reliability of the device in complex construction environments such as high dust concentration and high humidity is significantly enhanced;

[0025] 3. The present invention integrates the gas detection device with the single-arm tunnel boring machine, which can run synchronously with the tunneling operation, thereby improving construction efficiency and safety assurance capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A three-dimensional diagram of the overall device of the present invention;

[0027] Figure 2 For the present invention Figure 1 A three-dimensional diagram of the structure inside the middle cover;

[0028] Figure 3 A three-dimensional diagram of the part where the detection tube of the present invention is located;

[0029] Figure 4 A three-dimensional diagram of the exhaust pipe of the present invention;

[0030] Figure 5 A three-dimensional diagram of the internal structure of the connecting pipe of the present invention;

[0031] Figure 6 A three-dimensional diagram of the location of the compression spring of the present invention;

[0032] Figure 7 The present invention discloses a flow chart of a method for detecting gas in a small-section tunnel excavated by a single-arm tunnel boring machine.

[0033] In the figure: 1. shell; 2. rotating shaft; 3. drill bit; 4. cover body; 5. gear 1; 6. gear ring; 7. gear 2; 8. driven shaft; 81. oblique annular groove; 9. detection cylinder; 10. piston cylinder; 101. piston plate; 11. L-shaped transmission rod; 111. LED light board; 12. intake pipe; 13. exhaust pipe; 14. connecting pipe; 15. electromagnet assembly; 16. metal semi-cylinder; 17. locking rebound cylinder; 18. support rod; 19. pressure sensitive switch; 20. bottom cylinder; 21. locking assembly; 22. reset spring; 23. locking arm; 24. locking head; 25. pressure rod; 26. pressure block; 27. compression spring; 28. guide hole; 29. ​​insertion rod; 30. connecting strip; 31. limit ring. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figures 1 to 7 The present invention provides a technical solution: a method for detecting gas in a small-section tunnel excavated by a single-arm tunnel boring machine, comprising the following steps:

[0036] S1. Excavation sampling: As the rotating shaft 2 carries the drill bit 3 to excavate a small section of the tunnel, the air in the tunnel during the excavation process is filtered and extracted through the sampling module;

[0037] Through the coordinated rotation of the rotating shaft 2 and the cover body 4, all-round extraction of tunnel air is achieved to avoid detection blind spots;

[0038] S2, air detection: optically detect the air after filtering out the particle interference in the detection tube 9;

[0039] S3, detection result conversion: the infrared sensor in the piston cylinder 10 sends out a detection signal, and then the current transmitter converts the detection signal into an electrical signal output; the current transmitter is connected to the signal conditioning module, and the signal conditioning module conditions the electrical signal and transmits it to the signal conditioning circuit;

[0040] S4. Visual display of test results: The test results are determined by the brightness change and flickering change of the LED light board 111 electrically connected to the conditioning circuit.

[0041] A gas detection device for excavating a small-section tunnel with a single-arm tunnel boring machine, comprising a shell 1 arranged on the main body of the single-arm tunnel boring machine and a rotating shaft 2 that rotates on a fixed axis in the shell 1, and a drill bit 3 for excavating a small-section tunnel is fixedly connected to the rotating shaft 2 at one end away from the shell 1, characterized in that: a cover body 4 that is coaxially connected to the rotating shaft 2 and is rotatably connected to the shell 1, a gear 1 5 is fixedly sleeved on the arc profile of the rotating shaft 2 at one end away from the drill bit 3, a ring gear 6 is fixedly connected to the end of the shell 1 facing the drill bit 3, a gear 2 7 is transmission-engaged between the gear 1 5 and the ring gear 6, a driven shaft 8 is coaxially fixedly connected to the inner wall of the gear 2 7, the driven shaft 8 passes through and is rotatably connected to a detection tube 9, and the driven shaft 8 passes through the cover body 4 and is rotatably connected to the cover body 4 on a fixed axis.

[0042] refer to Figure 1 , Figure 2 and Figure 3 , the extracted air is optically analyzed and detected in the detection tube 9, the housing 1 is arranged on the main body of the single-arm tunnel boring machine to provide support for the rotating shaft 2 and the rotating shaft 2 during rotation, and the rotating shaft 2 drives the rotation of the drill bit 3, and the drill bit 3 performs a small-section excavation operation in the tunnel;

[0043] By setting the cover 4, the mechanical structure inside the cover 4 is protected to prevent the gravel dust generated during the excavation process from entering therein and interfering with the stable operation of the structure;

[0044] The rotating shaft 2 drives the gear 1 5 to rotate synchronously. With the rotation of the rotating shaft 2, the cover 4 on it rotates accordingly, and the gear 2 7 between the gear 1 5 and the ring gear 6 rotates accordingly, and the detection cylinder 9 in the gear 2 7 rotates on the cover 4 accordingly. At the same time, the cover 4 rotates with the rotating shaft 2 and assists the driven shaft 8 and the gear 2 7 to revolve around the central axis of the rotating shaft 2 as the rotation center.

[0045] The extracted air changes at any time with the rotation position of the cover 4, so as to realize comprehensive sampling of air in all directions in the tunnel;

[0046] Furthermore, one end of the detection tube 9 away from the shell 1 is fixed on the cover body 4, and an infrared sensor for detecting gas components in the air is provided in the detection tube 9. The infrared sensor is electrically connected in sequence to the current transmitter, the signal conditioning module and the signal conditioning circuit.

[0047] Infrared sensor: Infrared sensor is the core device used to detect gas components in the air. Through the infrared absorption method, the sensor uses the absorption characteristics of gas molecules to infrared radiation of specific wavelengths to detect the concentration of gas.

[0048] Detection principle: When infrared light passes through an air sample containing gas, different gas molecules absorb infrared light of different wavelengths, causing the light intensity to change. The infrared sensor converts the change in absorbed light intensity into an electrical signal, which is positively correlated with the gas concentration.

[0049] The sensor has the characteristics of high sensitivity, high stability and non-contact measurement, and can sense changes in gas concentration in the air in real time.

[0050] Current transmitter: The current transmitter is responsible for converting the original detection signal output by the infrared sensor into a standardized current signal output.

[0051] The signal output by the infrared sensor is amplified and standardized, and the signal conversion is realized through the circuit. The standard current signal of 4-20mA is output to ensure that the signal can meet the input requirements of the industrial control system and maintain stability and anti-interference ability during long-distance transmission. The converted current signal has strong anti-interference ability, which is especially suitable for scenes with complex environments such as mines and tunnels. It supports long-distance transmission, which facilitates data transmission to remote signal conditioning modules and monitoring equipment.

[0052] Signal conditioning module: The signal conditioning module further processes the standard electrical signal output by the current transmitter, mainly including signal filtering, amplification, linearization and digitization to ensure that the signal can be correctly identified by the downstream signal conditioning circuit or control system.

[0053] Filtering: Eliminate interference signals or high-frequency noise that may occur during transmission to ensure signal stability and reliability. Amplification: If the signal amplitude is low, the signal is appropriately enhanced through the amplification circuit to improve the sensitivity and resolution of the detection system. Linearization: Ensure that the relationship between the signal and the gas concentration remains linear to facilitate subsequent data analysis and processing. Digitization: In some designs, the signal conditioning module includes an analog-to-digital conversion ADC function to convert analog signals into digital signals for communication with digital systems.

[0054] Signal conditioning circuit: The signal conditioning circuit is one of the core modules of the system, which receives the conditioned electrical signal and further uses it for processing control logic or other feedback systems.

[0055] The infrared sensor first detects the change in gas concentration in the air and converts it into an electrical signal;

[0056] The current transmitter standardizes the detection signal and converts it into a standard current signal of 4-20mA to meet the requirements of industrial signal transmission;

[0057] The signal conditioning module processes, removes noise, amplifies and linearizes the standard current signal to ensure the accuracy of signal transmission;

[0058] The signal conditioning circuit receives the processed signal, performs logic judgment and control, and triggers the brightness and flashing effect of the LED light board 111 structure subsequently connected in series in this solution, so as to facilitate the operator's intuitive visual judgment.

[0059] Embodiment 2 is basically the same as Embodiment 1, and furthermore, a sampling module for extracting air from the excavation environment is further provided on the cover body 4, and the sampling module includes a piston cylinder 10, and the piston cylinder 10 passes through and is fixed on the cover body 4, and the inner wall of the piston cylinder 10 is axially limited and slidably connected with a piston plate 101, and an L-shaped transmission rod 11 is fixedly connected to the side of the piston plate 101 away from the shell 1, and an inclined annular groove 81 is opened on the arc profile of the driven shaft 8, and the end of the L-shaped transmission rod 11 away from the piston plate 101 extends into the inclined annular groove 81 and is aligned with the inclined annular groove The inner wall of the piston cylinder 81 is slidably connected, and an intake pipe 12 and an exhaust pipe 13 are penetrated and fixedly connected on the arc profile of the piston cylinder 10, and the intake pipe 12 and the exhaust pipe 13 are centrally symmetrical with the central axis of the piston cylinder 10, and the end of the exhaust pipe 13 away from the piston cylinder 10 penetrates the detection cylinder 9 and extends into the detection cylinder 9, and a one-way intake valve is fixedly connected in the intake pipe 12 and the exhaust pipe 13, and a filter screen for filtering the sampled air is fixedly connected to the inner wall of the intake pipe 12, and a through hole for discharging the detected air is opened on the end of the detection cylinder 9 away from the L-shaped transmission rod 11;

[0060] refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 ;

[0061] The sampling module transfers the extracted air sample to the detection tube 9, and performs corresponding optical detection in the detection tube 9;

[0062] First, the piston plate 101 can only perform axial reciprocating movement in the piston cylinder 10, so that the movement trajectory of the L-shaped transmission rod 11 is limited, and a relative movement is generated between the L-shaped transmission rod 11 and the driven shaft 8 after rotation, and under the guidance of the oblique annular groove 81 on the driven shaft 8, the L-shaped transmission rod 11 brings the piston plate 101 to perform axial reciprocating movement in the piston cylinder 10;

[0063] As a result, the volume inside the piston cylinder 10 increases or decreases due to the influence of the piston plate 101, so that the air pressure inside the piston cylinder 10 increases or decreases accordingly.

[0064] When the air pressure in the piston cylinder 10 decreases, external air will enter the piston cylinder 10 through the air inlet pipe 12 and the one-way valve in the air inlet pipe 12. At this time, the air added into the piston cylinder 10 will be filtered through the filter in the air inlet pipe 12 to prevent debris particles generated during the excavation process from entering and affecting the accuracy of subsequent optical detection results.

[0065] On the contrary, when the internal air pressure of the piston cylinder 10 increases, the high-pressure gas will enter the detection cylinder 9 through the exhaust pipe 13 and the one-way valve in the exhaust pipe 13. Finally, the filtered air is finally transferred to the detection cylinder 9, and the corresponding optical detection is performed in the detection cylinder 9.

[0066] Finally, the air collected in the detection cylinder 9 is transferred and discharged through the through holes thereon.

[0067] An LED light board 111 for displaying the detection results is provided on the arc-shaped contour of the shell 1, wherein the LED light board 111 is slidably connected to the shell 1, wherein the brightness of the LED light board 111 is positively correlated with the gas content in the air, and when the shell 1 flashes, it means that the gas content in the air has reached the designed threshold, and it is necessary to stop construction and carry out corresponding gas treatment.

[0068] Furthermore, a connecting tube 14 is fixedly connected to the arc-shaped contour of the cover body 4, the LED lamp board 111 is fixedly connected to the surface of the connecting tube 14, the end of the connecting tube 14 away from the housing 1 is fixedly connected to an electromagnet assembly 15 electrically connected to the conditioning circuit, and two metal semi-cylinders 16 that are magnetically matched with the electromagnet assembly 15 are axially limited and slidably connected in the connecting tube 14, and a locking device axially slidably connected in the connecting tube 14 is provided on the side of the metal semi-cylinder 16 away from the electromagnet assembly 15. The rebound cylinder 17, the side of the locking rebound cylinder 17 away from the metal semi-cylinder 16 is fixedly connected with a support rod 18, the end of the support rod 18 away from the locking rebound cylinder 17 is fixedly connected with a pressure-sensitive switch 19 that electrically connects the conditioning circuit with the LED light board 111, the side of the pressure-sensitive switch 19 away from the support rod 18 is movably connected with a bottom cylinder 20 fixed to the inner wall of the connecting tube 14, and the metal semi-cylinder 16 is provided with a locking component 21 that keeps the locking rebound cylinder 17 away from the bottom cylinder 20.

[0069] refer to Figure 5 When the pressure-sensitive switch 19 is released from the bottom cylinder 20, the LED light board 111 is in a circuit-connected state. In the absence of gas, the brightness of the LED light board 111 is the lowest at this time;

[0070] Among them, after the infrared sensor detects the gas concentration, it will convert the detection results into electrical signals.

[0071] The current transmitter further converts these signals into standardized current signals in the range of 4 to 20 mA, which are industrial standard signals and represent the corresponding detection range of 0% to 100% of the gas concentration.

[0072] The signal conditioning module and conditioning circuit filter, amplify, calibrate and process the signal. The final output current signal will have a linear functional relationship with the change of gas concentration.

[0073] High gas concentration: When the infrared sensor detects a higher gas concentration, the output signal is stronger, and after passing through the conditioning circuit, the output current will also increase.

[0074] Low gas concentration: When the infrared sensor detects low concentration or no gas, the output signal is weak and the current output by the conditioning circuit will also decrease.

[0075] Linear relationship: In this solution, the conditioning circuit will maintain a linear relationship between the output current and the gas concentration. The details are as follows:

[0076] The gas concentration is 0%, and the corresponding output current is 4mA (minimum current).

[0077] The gas concentration is 100%, and the corresponding output current is 20mA.

[0078] When the output current reaches the maximum, the magnetic attraction of the electromagnet assembly 15 also reaches the maximum, and the metal semi-cylinder 16 is moved as a whole. Figure 5 The metal semi-cylinder 16 is attracted and moved in the direction indicated by the arrow A, and the locking component 21 on the metal semi-cylinder 16 moves synchronously with the locking rebound cylinder 17, and finally the support rod 18 and the pressure-sensitive switch 19 move synchronously and break away from the contact with the bottom cylinder 20, so that the LED light board 111 suddenly flashes out after the brightness reaches the highest level;

[0079] Furthermore, a return spring 22 is fixedly connected between the bottom cylinder 20 and the locking rebound cylinder 17 to keep the pressure-sensitive switch 19 in continuous contact with the surface of the bottom cylinder 20 .

[0080] By setting the reset spring 22, when the detected gas concentration continues to increase and the corresponding output current increases, the pressure-sensitive switch 19 can still maintain contact with the bottom cylinder 20, and the position of the corresponding LED light board 111 can roughly indicate the direction of high gas concentration, which is convenient for manual further investigation; in this solution, the number of LED light boards 111 and gear 2 7 corresponds to 4;

[0081] Furthermore, the locking assembly 21 includes two locking arms 23 which are rotatably connected between two metal semi-cylinders 16 on a fixed axis, and a locking head 24 which is locked and matched with the two locking arms 23 at the same time is fixedly connected to the side of the locking rebound cylinder 17 facing the metal semi-cylinder 16, and the opposite surfaces of the two locking arms 23 are fixedly connected with a pressure rod 25, and the opposite ends of the two pressure rods 25 are fixedly connected with a pressure block 26, and the opposite surfaces of the two pressure blocks 26 are fixedly connected with the same compression spring 27 in a compressed state, and the ends of the two locking arms 23 facing the locking head 24 are both arc-shaped surfaces adapted to the locking head 24, and a guide hole 28 is provided at the center of the electromagnet assembly 15 to guide the deflection of the ends of the two locking arms 23 away from the locking rebound cylinder 17.

[0082] refer to Figure 5 and Figure 6 ;

[0083] When the two locking arms 23 in the locking assembly 21 are in accordance with Figure 5 When the guide hole 28 is moved in the direction of the middle arrow A, the guide hole 28 restricts the movement and the guide hole 28 causes the two locking arms 23 to rotate synchronously and release the contact and locking of the locking head 24 .

[0084] In the locked state, the compression spring 27 is in a compressed state, which squeezes the compression block 26 and the compression rod 25 at both ends, thereby completing the buckling and locking of the locking head 24;

[0085] With the release of the lock, the pressure-sensitive switch 19 will contact the bottom cylinder 20 again under the elastic force of the reset spring 22, and the contact process is repeated and eventually tends to be continuous. During this process, the LED light board 111 will flash repeatedly and eventually tend to be constantly on, thereby obtaining an obvious visual change effect, which is convenient for manual detection in time.

[0086] Furthermore, the opposite surfaces of the two metal semi-cylinders 16 on the side away from the locking rebound cylinder 17 are fixedly connected with the same insert rod 29, and the inner wall of the guide hole 28 is fixedly connected with two symmetrical connecting strips 30, and the opposite surfaces of the two connecting strips 30 are fixedly connected with a limiting ring 31 axially penetrated by the insert rod 29 and slidably connected.

[0087] The two metal semi-cylinders 16 are further connected by the arrangement of the insertion rod 29, and the limiting ring 31 is supported by the arrangement of the two connecting strips 30. The movement trajectory of the insertion rod 29 is further limited by the limiting ring 31 to ensure the stability of the structural operation.

[0088] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for detecting gas in a small-section tunnel excavated by a single-arm tunnel boring machine, characterized in that: The following steps are involved: S1. Excavation sampling: During the process of excavating a small section of the tunnel with the rotating shaft (2) and the drill bit (3), the air in the tunnel is filtered and extracted through the sampling module; Through the coordinated rotation of the rotating shaft (2) and the cover body (4), all-round extraction of tunnel air is achieved, thereby avoiding detection blind areas; S2, air detection: the air after filtering out the particle interference is optically detected in the detection tube (9); S3, detection result conversion: the infrared sensor in the piston cylinder (10) sends out a detection signal, and then the current transmitter converts the detection signal into an electrical signal output; the current transmitter is connected to the signal conditioning module, and the signal conditioning module conditions the electrical signal and transmits it to the signal conditioning circuit; S4. Visual display of the detection results: the detection results are judged by the brightness change and flickering change of the LED light board (111) electrically connected to the conditioning circuit.

2. A gas detection device for a small-section tunnel excavated by a single-arm tunnel boring machine, applied to a gas detection method for a small-section tunnel excavated by a single-arm tunnel boring machine as claimed in the claim, comprising a housing (1) arranged on a main body of the single-arm tunnel boring machine and a rotating shaft (2) rotating about a fixed axis in the housing (1), a drill bit (3) for excavating a small-section tunnel being fixedly connected to one end of the rotating shaft (2) away from the housing (1), characterized in that: The housing (1) is rotatably connected to a cover body (4) coaxially connected to the rotating shaft (2); a gear 1 (5) is fixedly sleeved on an arc-shaped contour at one end of the rotating shaft (2) away from the drill bit (3); a gear ring (6) is fixedly connected to the end of the housing (1) facing the drill bit (3); a gear 2 (7) is meshed with the gear 1 (5) and the gear ring (6); a driven shaft (8) is coaxially fixedly connected to the inner wall of the gear 2 (7); the driven shaft (8) passes through and is rotatably connected to a detection cylinder (9); the driven shaft (8) passes through the cover body (4) and is rotatably connected to the cover body (4) on a fixed axis.

3. A gas detection device for excavating a small-section tunnel using a single-arm tunnel boring machine according to claim 2, characterized in that: The end of the detection tube (9) away from the housing (1) is fixed on the cover body (4). The detection tube (9) is provided with an infrared sensor for detecting gas components in the air. The infrared sensor is electrically connected in sequence to the current transmitter, the signal conditioning module and the signal conditioning circuit.

4. A method for detecting gas in a small-section tunnel excavated by a single-arm tunnel boring machine according to claim 3, characterized in that: The cover body (4) is also provided with a sampling module for extracting air from the excavation environment, the sampling module comprising a piston cylinder (10), the piston cylinder (10) passes through and is fixed on the cover body (4), the inner wall of the piston cylinder (10) is axially limited and slidably connected with a piston plate (101), the side of the piston plate (101) away from the housing (1) is fixedly connected with an L-shaped transmission rod (11), the arc-shaped profile of the driven shaft (8) is provided with an inclined annular groove (81), the end of the L-shaped transmission rod (11) away from the piston plate (101) extends into the inclined annular groove (81) and is slidably connected to the inner wall of the inclined annular groove (81), An air intake pipe (12) and an air exhaust pipe (13) are penetrated and fixedly connected to the arcuate contour of the piston cylinder (10); the air intake pipe (12) and the air exhaust pipe (13) are centrally symmetrical with respect to the central axis of the piston cylinder (10); the end of the air exhaust pipe (13) away from the piston cylinder (10) penetrates the detection cylinder (9) and extends into the detection cylinder (9); one-way air intake valves are fixedly connected to the inside of the air intake pipe (12) and the exhaust pipe (13); a filter screen for filtering sampled air is fixedly connected to the inner wall of the air intake pipe (12); and a through hole for discharging detected air is provided at the end of the detection cylinder (9) away from the L-shaped transmission rod (11).

5. The method for detecting gas in a small-section tunnel excavated by a single-arm tunnel boring machine according to claim 4, characterized in that: An LED light panel (111) for displaying the detection result is provided on the arc-shaped profile of the housing (1).

6. A method for detecting gas in a small-section tunnel excavated by a single-arm tunnel boring machine according to claim 5, characterized in that: A connecting tube (14) is fixedly connected to the arc-shaped contour of the cover body (4); the LED lamp panel (111) is fixedly connected to the surface of the connecting tube (14); an end of the connecting tube (14) away from the housing (1) is fixedly connected to an electromagnet assembly (15) electrically connected to the conditioning circuit; two metal semi-cylinders (16) that are magnetically matched with the electromagnet assembly (15) are axially limited and slidably connected in the connecting tube (14); a locking rebound cylinder (16) that is axially slidably connected in the connecting tube (14) is provided on one side of the metal semi-cylinder (16) away from the electromagnet assembly (15). 17), a side of the locking rebound cylinder (17) away from the metal semi-cylinder (16) is fixedly connected to a support rod (18), an end of the support rod (18) away from the locking rebound cylinder (17) is fixedly connected to a pressure-sensitive switch (19) electrically connecting the conditioning circuit to the LED light board (111), a side of the pressure-sensitive switch (19) away from the support rod (18) is movably connected to a bottom cylinder (20) fixed to the inner wall of the connecting tube (14), and a locking component (21) is provided on the metal semi-cylinder (16) for keeping the locking rebound cylinder (17) away from the bottom cylinder (20).

7. A method for detecting gas in a small-section tunnel excavated by a single-arm tunnel boring machine according to claim 6, characterized in that: A return spring (22) is fixedly connected between the bottom cylinder (20) and the locking rebound cylinder (17) to keep the pressure-sensitive switch (19) in continuous contact with the surface of the bottom cylinder (20).

8. A method for detecting gas in a small-section tunnel excavated by a single-arm tunnel boring machine according to claim 7, characterized in that: The locking assembly (21) comprises two locking arms (23) which are rotatably connected between two metal semi-cylinders (16) with a fixed axis; a locking head (24) which is locked and matched with the two locking arms (23) is fixedly connected to one side of the locking rebound cylinder (17) facing the metal semi-cylinder (16); a pressure rod (25) is fixedly connected to the opposite surfaces of the two locking arms (23); a pressure block (26) is fixedly connected to the opposite ends of the two pressure rods (25); a compression spring (27) which is in a compressed state is fixedly connected to the opposite surfaces of the two pressure blocks (26); the ends of the two locking arms (23) facing the locking heads (24) are arc-shaped surfaces which are matched with the locking heads (24); and a guide hole (28) is provided at the center of the circle of the electromagnet assembly (15) for guiding the deflection of the ends of the two locking arms (23) away from the locking rebound cylinder (17).

9. A method for detecting gas in a small-section tunnel excavated by a single-arm tunnel boring machine according to claim 8, characterized in that: The opposite surfaces of the two metal semi-cylinders (16) on the side away from the locking rebound cylinder (17) are fixedly connected with a same insertion rod (29), the inner wall of the guide hole (28) is fixedly connected with two symmetrical connecting strips (30), and the opposite surfaces of the two connecting strips (30) are fixedly connected with a limiting ring (31) axially penetrated by the insertion rod (29) and slidably connected.

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