A construction device and method for cantilever excavation of a tailrace tunnel of a pumped storage power station

Abstract

This invention discloses a cantilever tunneling device and its construction method for a pumped storage power station tailrace tunnel. The device includes a cutting head and a transfer chamber. The transfer chamber is located inside the cutting head, and multiple sets of cutting teeth protruding from the cutting head are arranged on the outside of the transfer chamber. Multiple sets of mounting holes for accommodating the cutting teeth are penetrated through the outside of the cutting head. Each cutting tooth includes a mounting cylinder that penetrates into the mounting hole. The mounting cylinder is interference-fitted with the mounting hole. A hollow cylindrical toothed rod coaxially penetrates the inside of the mounting cylinder, and the toothed rod is clearance-fitted with the mounting cylinder. One end of the toothed rod extends into the cutting head and into the inner side of the transfer chamber. The advantages are: by setting movable cutting teeth on the outside of the cutting head, this invention replaces the fixed cutting teeth of existing cantilever tunneling machines, ensuring that the cutting teeth automatically spray water to cool and assist excavation during the pressure cutting process of the soil layer at the tunnel face. This improves the waste problem caused by the continuous water spraying of existing cutting teeth, and is energy-saving and environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of cantilever tunneling technology for tailrace tunnels in hydropower projects, specifically relating to a cantilever tunneling construction device and its construction method for a pumped storage power station tailrace tunnel. Background Technology

[0002] Currently, with the rapid development of engineering construction in my country, the construction and structural requirements for underground cavern spaces are becoming increasingly stringent, and the span requirements are also increasing. However, the span of underground engineering projects in my country is generally small at present. In addition to meeting functional requirements, underground engineering projects must also place special emphasis on safety during construction and the long-term safety and stability of underground projects. The excavation method of underground caverns is related to the stability of the surrounding rock and the construction speed.

[0003] The construction of tailrace tunnels for pumped-storage power stations mainly includes two methods: blasting and tunneling with cantilever machines. Blasting has drawbacks such as uncontrolled dimensional deviations, construction hazards, and environmental damage. Blasting under residential areas carries high risks, and with increasingly stringent explosive control, it is costly and inefficient. Cantilever machine construction, on the other hand, is safer, more flexible, and more efficient. This comparison shows that as the advantages of cantilever machines become more apparent and their application scope expands, they will become one of the leading technologies for tailrace tunnel construction in China in the future. Summary of the Invention

[0004] The purpose of this invention is to provide a cantilever tunneling construction device and method for the tailrace tunnel of a pumped storage power station to solve the above-mentioned problems. By setting movable cutting teeth on the outside of the cutting head, replacing the fixed cutting teeth of the existing cantilever tunneling machine, it ensures that the cutting teeth automatically spray water to cool and assist excavation during the pressure cutting process of the soil layer at the tunnel face, thereby improving the waste problem caused by the continuous water spraying of the existing cutting teeth, and saving energy and protecting the environment. During the rotation of the cutting head, multiple sets of guide cylinders and scraper blades on the outside are kept rotating simultaneously to synchronously transport the debris generated by the cutting of the tailrace tunnel face, and assist the scraper claw of the cantilever tunneling machine in scraping and conveying the debris, ensuring that the debris generated by the tunnel excavation can be discharged to the outside of the tunnel in a timely manner, improving construction efficiency, as detailed below.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides a cantilever tunneling construction device for the tailrace tunnel of a pumped storage power station, comprising a cutting head and a transfer cavity. The transfer cavity is located inside the cutting head, and multiple sets of cutting teeth protruding from the cutting head are provided outside the transfer cavity.

[0006] The cutting head has multiple sets of mounting holes for accommodating cutting teeth. Each cutting tooth includes a mounting cylinder that passes through the inner side of the mounting hole. The mounting cylinder is interference-fitted with the mounting hole. A hollow cylindrical toothed rod passes coaxially through the inside of the mounting cylinder. The toothed rod is clearance-fitted with the mounting cylinder. One end of the toothed rod extends into the cutting head and passes through the inner side of the transfer cavity. The toothed rod is clearance-fitted with the transfer cavity. An end cap that fits against the inner wall of the transfer cavity is fixed to the end of the toothed rod extending into the transfer cavity. A connecting hole passes through the middle of the toothed rod outside the end cap. A retaining ring is fixed to the outside of the toothed rod between the cutting head and the transfer cavity. A push-pull retaining ring is sleeved on the outside of the toothed rod between the cutting head and the transfer cavity to keep the end cap pressed against the inner wall of the transfer cavity.

[0007] Preferably, a movable ring is fitted around the outside of the mounting cylinder on the outer side of the cutting head. The movable ring rotates with the mounting cylinder, and multiple sets of wave-shaped breaking teeth are arranged around the outside of the movable ring.

[0008] Preferably, the inner side of the cutting head is provided with multiple sets of fixing frames supporting the transfer cavity, and the end of the cutting head has a transverse through-hole, and the outer circumference of the cutting head on the outer side of the end hole is provided with multiple sets of bolt holes.

[0009] Preferably, the cutting head end inside the end hole is provided with a drilling part, the drilling part including a constraint plate extending into the end hole, a drill bit extending out of the end hole of the cutting head is fixed outside the constraint plate, and a plurality of fixing bolts with through bolt holes are arranged around the outside of the constraint plate, the constraint plate and the fixing bolts are threadedly engaged to fix the constraint plate and the cutting head.

[0010] Preferably, the cutting head is provided with multiple sets of spirally extending guide grooves on its outer side, and multiple sets of cutting teeth are correspondingly arranged on the inner side of the guide grooves. The cutting head includes a conical part that accommodates the transfer cavity. The larger side of the conical part is connected to a cylindrical part, and a support box is provided on the outer side of the cylindrical part.

[0011] Preferably, the support box is a cylindrical structure, and a transmission component for driving the cutting head to rotate is provided inside the support box. Multiple sets of auxiliary components are arranged around the outside of the cylindrical part, and multiple sets of receiving holes for accommodating the auxiliary components are evenly distributed on the outer circumference of the cylindrical part.

[0012] Preferably, the support box has an inner ring fixed on the inner side of the end away from the cutting head, and multiple sets of transversely through pre-drilled holes are arranged around the inner ring. The support box has a rotating frame that supports the transmission assembly. The transmission assembly includes a cutting shaft that transversely passes through the rotating frame. The cutting shaft and the rotating frame are rotatably engaged by a thrust bearing. A transmission gear is fixed at one end of the cutting shaft that extends into the cutting head. An internal gear ring is fixed on the inner side of the end of the cutting head, and the internal gear ring meshes with the transmission gear.

[0013] Preferably, a linkage cylinder is provided below the cutting shaft and is coaxially distributed with the cutting head. A positioning frame that supports the rotation of the linkage cylinder is fixed inside the cutting head. The linkage cylinder and the cutting shaft are connected by a belt pulley transmission mechanism. A synchronous gear is fixed outside the linkage cylinder.

[0014] Preferably, the auxiliary component includes a feed shaft laterally disposed within the receiving hole, a guide cylinder extending out of the receiving hole fixed to the outside of the feed shaft, a spirally extending scraper blade disposed on the outside of the guide cylinder, and an auxiliary gear meshing with a synchronous gear fixed to the outside of the feed shaft, a supply pipe extending out of the linkage cylinder passing through the end of the transfer cavity, and the supply pipe and the linkage cylinder being clearance-fitted, the connection between the supply pipe and the transfer cavity being rotatably fitted by a sealed bearing, and a flange fixed to the outer end of the supply pipe.

[0015] The construction method of the cantilever tunneling construction device for the tailrace tunnel of the pumped storage power station includes the following steps: a. Drilling and blasting methods are prohibited when the tailrace tunnel passes under a residential area. When cantilever tunneling is required, the cantilever tunneling machine should be positioned and the support box and the telescopic part of the tunneling machine should be installed and fixed. The cutting motor of the cantilever tunneling machine drives the cutting reducer to rotate. The cutting reducer drives the cutting shaft to rotate the transmission gear. The meshing of the transmission gear and the internal gear ring drives the cutting head to rotate inside the support box. The high-speed rotating cutting head and its multiple sets of cutting teeth move and excavate the tunnel face.

[0016] b. During the high-speed rotation of the cutting head and supporting cutting teeth, ensure that the flange of the supply pipe on the outside of the transfer chamber is connected to the water supply system, and keep the transfer chamber fully filled with water. When the cutting head drives the cutting teeth to rotate and cut the soil layer of the working face, several sets of cutting teeth in contact with the working face are subjected to cutting pressure. At this time, the tooth bar of the cutting tooth is compressed and retracts into the mounting cylinder. At the same time, the spring is compressed. During the movement of the tooth bar, the connecting hole at its end is synchronously drawn into the transfer chamber, thereby realizing the connection between the set of compressed tooth bars and the transfer chamber. At this time, the water in the transfer chamber enters the inner side of the tooth bar along the connecting hole and sprays outward, realizing the process of spraying water to cool the cutting teeth and spraying water to soften the soil layer of the working face in the contact area.

[0017] c. When the transmission gear drives the internal gear ring to support the cutting head in a rotating state, the cutting shaft drives the linkage cylinder and synchronous gear to rotate through the belt transmission mechanism. The cutting shaft, cutting head and linkage cylinder all rotate in the same direction. The synchronous gear on the outside of the linkage cylinder meshes with the auxiliary gear, thereby synchronously driving the auxiliary components to rotate during the rotation of the cutting head. This keeps the guide cylinder and scraper blades in a state of opposite rotation to the cutting head under the support of the feed shaft. In this way, multiple sets of scraper blades distributed around the cutting head will be used to roll and transport the soil layer cut and scraped by the cutting head outward.

[0018] The beneficial effects are: This invention replaces the fixed cutting teeth of existing cantilever tunneling machines by setting movable cutting teeth on the outside of the cutting head. This ensures that the cutting teeth automatically spray water to cool and assist excavation during the pressure cutting process of the soil layer at the tunnel face, thus improving the waste problem caused by the continuous water spraying of existing cutting teeth and saving energy and protecting the environment.

[0019] During the rotation of the cutting head, multiple sets of guide cylinders and scraper blades on the outside are rotated simultaneously to transport the debris generated by the cutting of the tailrace tunnel face in a synchronous manner. This assists the scraper claw of the cantilever tunneling machine in scraping and conveying the debris, ensuring that the debris generated by tunnel excavation can be discharged to the tunnel entrance in a timely manner, thereby improving construction efficiency. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a front view structural diagram of the present invention; Figure 2 This is a three-dimensional structural schematic diagram of the present invention; Figure 3 This is a partial structural breakdown diagram of the present invention; Figure 4 This is a three-dimensional structural breakdown diagram of the present invention; Figure 5 This is a three-dimensional structural schematic diagram of the cutting tooth of the present invention; Figure 6 This is a three-dimensional structural diagram of the transfer cavity in this invention; Figure 7 This is a front sectional view of the present invention; Figure 8 yes Figure 7 Enlarged view of the structure at point A; Figure 9 This is a three-dimensional structural schematic diagram of another aspect of the present invention; Figure 10 This is a partial structural breakdown diagram of another aspect of the present invention.

[0022] The annotations in the attached figures are explained as follows: 1. Cutting head; 101. Mounting hole; 102. Fixing bracket; 103. End hole; 104. Bolt hole; 105. Guide groove; 106. Receiving hole; 107. Internal gear ring; 108. Positioning bracket; 2. Cutting tooth; 201. Tooth bar; 201a. Connecting hole; 202. Mounting cylinder; 203. Retaining ring; 204. End cap; 205. Spring; 206. Moving ring; 206a. Crushing tooth; 3. Transfer chamber; 301. Supply pipe; 3 01a, Flange; 302, Sealed Bearing; 4, Support Box; 401, Reserved Hole; 402, Rotating Frame; 5, Drilling Section; 501, Drill Bit; 502, Constraint Disc; 503, Fixing Bolt; 6, Transmission Assembly; 601, Cutting Shaft; 602, Transmission Gear; 603, Linkage Cylinder; 604, Synchronization Gear; 7, Auxiliary Assembly; 701, Feed Shaft; 702, Guide Cylinder; 702a, Scraper Blade; 703, Auxiliary Gear. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0024] See Figures 1-10 As shown, the present invention provides a cantilever tunneling construction device for the tailrace tunnel of a pumped storage power station, including a cutting head 1 and a transfer chamber 3. The transfer chamber 3 is located inside the cutting head 1, and multiple sets of cutting teeth 2 protruding from the cutting head 1 are provided on the outside of the transfer chamber 3. The cutting teeth 2 are used to rotate under the support of the cutting head 1 to realize the cutting and tunneling of the tailrace tunnel face.

[0025] The cutting head 1 has multiple sets of mounting holes 101 through its exterior to accommodate cutting teeth 2. Each cutting tooth 2 includes a mounting cylinder 202 that penetrates the inner side of the mounting hole 101. The mounting cylinder 202 is interference-fitted with the mounting hole 101 to ensure a secure connection between the mounting cylinder 202 and the cutting head 1. A hollow cylindrical toothed rod 201 coaxially penetrates the interior of the mounting cylinder 202. The toothed rod 201 is clearance-fitted with the mounting cylinder 202 to ensure that when the toothed rod 201 presses against the soil layer at the external working face, it can... Under pressure, the toothed rod 201 retracts into the mounting cylinder 202, and one end of the toothed rod 201 extends into the inner side of the transfer cavity 3, with a clearance fit between the toothed rod 201 and the transfer cavity 3. An end cap 204, which fits against the inner wall of the transfer cavity 3, is fixed to the end of the toothed rod 201 extending into the transfer cavity 3, ensuring that the end cap 204 is tightly pressed against the inner wall of the transfer cavity 3 to maintain the seal at the point where the toothed rod 201 penetrates the transfer cavity 3. A connecting hole 201a passes through the middle of the toothed rod 201 outside the end cap 204. A retaining ring 203 is fixed to the outside of the toothed rod 201 between the cutting head 1 and the transfer chamber 3. A push-pull retaining ring 203 is sleeved on the outside of the toothed rod 201 between the cutting head 1 and the transfer chamber 3 to keep the end cover 204 pressed against the inner wall of the transfer chamber 3. When the outer end of the toothed rod 201 presses against the soil layer of the tunnel face that needs to be cut, the outer end of the toothed rod 201 is compressed and retracts into the mounting cylinder 202. At the same time, the spring 205 is compressed and the connecting hole 201a at the end of the toothed rod 201 moves into the transfer chamber 3. The transfer chamber 3 is pre-connected to the external water supply channel. At this time, the water in the transfer chamber 3 is sprayed outward along the connected sets of toothed rods 201 to cool down the sets of cutting teeth 2 that are actually cutting. The water sprayed from the end of the toothed rod 201 is used to spray water on the tunnel face at the cutting position of the cutting teeth 2 to loosen the soil layer, improve cutting efficiency, and reduce dust pollution.

[0026] As an optional implementation, a movable ring 206 is sleeved on the outside of the mounting cylinder 202 on the outer side of the cutting head 1. The movable ring 206 rotates with the mounting cylinder 202. Multiple sets of wave-shaped breaking teeth 206a are arranged around the outside of the movable ring 206. By setting rotatable breaking teeth 206a on the outside of the mounting cylinder 202 of the cutting teeth 2, the cutting contact area of ​​the cutting head 1 on the outer soil layer during rotation is increased, thereby further increasing the cutting and tunneling efficiency.

[0027] The inner side of the cutting head 1 is provided with multiple sets of fixed brackets 102 supporting the transfer cavity 3, and the end of the cutting head 1 has a transverse through-hole 103. The outer circumference of the cutting head 1 on the outer side of the end hole 103 is provided with multiple sets of bolt holes 104. The end of the cutting head 1 inside the end hole 103 is provided with a drilling part 5. The drilling part 5 includes a constraint plate 502 extending into the end hole 103. A drill bit 501 extending out of the end hole 103 of the cutting head 1 is fixed outside the constraint plate 502. Multiple sets of fixing bolts 503 passing through the bolt holes 104 are provided around the outer side of the constraint plate 502. The constraint plate 502 and the fixing bolts 503 are threadedly engaged to fix the constraint plate 502 and the cutting head 1.

[0028] The cutting head 1 has multiple sets of spirally extending guide grooves 105 on its outer side, and multiple sets of cutting teeth 2 are correspondingly arranged inside the guide grooves 105. The multiple sets of cutting teeth 2 are distributed along the spiral-shaped guide grooves 105 to ensure that the machine has better digging ability. The cutting head 1 includes a conical part that accommodates the transfer cavity 3. The larger side of the conical part is connected to a cylindrical part. A support box 4 is arranged on the outer side of the cylindrical part. The support box 4 is a cylindrical structure. The transmission component 6 that drives the cutting head 1 to rotate is arranged inside the support box 4. Multiple sets of auxiliary components 7 are arranged around the outer side of the cylindrical part, and multiple sets of receiving holes 106 for accommodating the auxiliary components 7 are evenly distributed on the outer circumference of the cylindrical part. The auxiliary components 7 are used to assist the cutting head 1 in discharging the debris generated by digging outward.

[0029] An inner ring is fixed to the inner side of the support box 4 away from the cutting head 1. Multiple sets of transverse through-holes 401 are arranged around the inner ring to facilitate fixing the support box 4 to the telescopic part of the cantilever tunneling machine through the through-holes 401. The support box 4 is provided with a rotating frame 402 that supports the transmission assembly 6. The transmission assembly 6 includes a cutting shaft 601 that transversely passes through the rotating frame 402. The cutting shaft 601 and the rotating frame 402 are rotatably engaged by a thrust bearing. A transmission gear 602 is fixed to one end of the cutting shaft 601 that extends into the cutting head 1. An internal gear ring 107 is fixed to the inner side of the end of the cutting head 1. The internal gear ring 107 meshes with the transmission gear 602.

[0030] Below the cutting shaft 601, there is a linkage cylinder 603 coaxially distributed with the cutting head 1. Inside the cutting head 1, there is a positioning frame 108 that supports the rotation of the linkage cylinder 603. The linkage cylinder 603 and the cutting shaft 601 are connected by a belt pulley transmission mechanism. A synchronous gear 604 is fixed outside the linkage cylinder 603. The synchronous gear 604 is used to synchronously drive multiple sets of auxiliary components 7 to rotate.

[0031] The auxiliary component 7 includes a feed shaft 701 horizontally disposed within the receiving hole 106. A guide cylinder 702 extending out of the receiving hole 106 is fixed to the outside of the feed shaft 701. A spirally extending scraper blade 702a is disposed on the outside of the guide cylinder 702. An auxiliary gear 703 meshing with a synchronous gear 604 is fixed to the outside of the feed shaft 701. A supply pipe 301 extending out of the linkage cylinder 603 passes through the end of the transfer chamber 3. The supply pipe 301 and the linkage cylinder 603 are clearance-fitted. The connection between the supply pipe 301 and the transfer chamber 3 is rotatably engaged by a sealed bearing 302 to ensure that the transfer chamber 3 can rotate synchronously with the cutting head 1. A flange 301a is fixed to the outer end of the supply pipe 301. The supply pipe 301 is connected to the external water supply system through the flange 301a, thereby ensuring that the transfer chamber 3 is always full of water during the tunneling process.

[0032] The construction method for the cantilever excavation construction device of the tailrace tunnel of a pumped storage power station includes the following steps: a. Drilling and blasting is prohibited when the tailrace tunnel passes under a residential area. When cantilever tunneling is required, the cantilever tunneling machine should be in place, and the support box 4 should be fixed to the telescopic part of the tunneling machine. The cutting motor of the cantilever tunneling machine drives the cutting reducer to rotate. The cutting reducer drives the cutting shaft 601 to drive the transmission gear 602 to rotate. The meshing action of the transmission gear 602 and the internal gear ring 107 drives the cutting head 1 to rotate inside the support box 4. The high-speed rotating cutting head 1 and its multiple sets of cutting teeth 2 move and excavate the tunnel face.

[0033] b. During the high-speed rotation of the cutting head 1 supporting the cutting teeth 2, ensure that the flange 301a of the supply pipe 301 on the outside of the transfer chamber 3 is connected to the water supply system, and keep the transfer chamber 3 in a fully loaded state. During the process of the cutting head 1 driving the cutting teeth 2 to rotate and cut the soil layer of the working face, several sets of cutting teeth 2 in contact with the working face are subjected to cutting pressure. At this time, the tooth bar 201 of the cutting teeth 2 is compressed and retracts into the mounting cylinder 202. At the same time, the spring 205 is compressed. During the movement of the tooth bar 201, the connecting hole 201a at its end is simultaneously drawn into the transfer chamber 3, thereby realizing the connection between the set of compressed tooth bars 201 and the transfer chamber 3. At this time, the water in the transfer chamber 3 enters the inner side of the tooth bar 201 along the connecting hole 201a and sprays outward, realizing the process of spraying water to cool the cutting teeth 2 and spraying water to soften the soil layer of the working face in the contact area and reduce dust.

[0034] c. When the transmission gear 602 drives the internal gear ring 107 to support the cutting head 1 in a rotating state, the cutting shaft 601 drives the linkage cylinder 603 and the synchronous gear 604 to rotate through the belt transmission mechanism. The cutting shaft 601, the cutting head 1 and the linkage cylinder 603 all rotate in the same direction. The synchronous gear 604 on the outside of the linkage cylinder 603 meshes with the auxiliary gear 703, thereby synchronously driving the auxiliary component 7 to rotate during the rotation of the cutting head 1. This keeps the guide cylinder 702 and the scraper blade 702a in a state of opposite rotation to the cutting head 1 under the support of the feed shaft 701. Thus, the soil layer cut and scraped by the cutting head 1 is rolled and transported outward by multiple sets of scraper blades 702a distributed around the cutting head 1.

[0035] By setting movable cutting teeth 2 on the outside of the cutting head 1 to replace the fixed cutting teeth 2 of the existing cantilever tunneling machine, it is ensured that the cutting teeth 2 automatically spray water to cool down and assist excavation during the pressure cutting process of the soil layer at the tunnel face, thereby improving the waste problem caused by the continuous water spraying of the existing cutting teeth 2, and saving energy and protecting the environment.

[0036] During the rotation of the cutting head 1, multiple sets of guide cylinders 702 and scraper blades 702a on the outside are rotated simultaneously to transport the debris generated by the cutting of the tailrace tunnel face in a synchronous manner, and assist the scraper claw of the cantilever tunneling machine in scraping and feeding the debris, so as to ensure that the debris generated by the tunnel excavation can be discharged to the outside of the tunnel in a timely manner, thereby improving construction efficiency.

[0037] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cantilever tunneling construction device for the tailrace tunnel of a pumped storage power station, characterized in that: It includes a cutting head (1) and a transfer cavity (3). The transfer cavity (3) is located inside the cutting head (1), and multiple sets of cutting teeth (2) protruding from the cutting head (1) are provided on the outside of the transfer cavity (3). The cutting head (1) has multiple sets of mounting holes (101) for accommodating cutting teeth (2) through its exterior. Each cutting tooth (2) includes a mounting cylinder (202) that penetrates the inside of the mounting hole (101). The mounting cylinder (202) is interference-fitted with the mounting hole (101). A hollow cylindrical toothed rod (201) coaxially penetrates the inside of the mounting cylinder (202). The toothed rod (201) is clearance-fitted with the mounting cylinder (202). One end of the toothed rod (201) extends into the cutting head (1) and penetrates the inside of the transfer cavity (3). The toothed rod (201) and the transfer cavity (3) are interlocked. The toothed rod (201) extends into the transfer cavity (3) and is fixed with an end cap (204) that fits against the inner wall of the transfer cavity (3). A through hole (201a) is passed through the middle of the toothed rod (201) on the outside of the end cap (204). A retaining ring (203) is fixed on the outside of the toothed rod (201) between the cutting head (1) and the transfer cavity (3). A push-stop retaining ring (203) is sleeved on the outside of the toothed rod (201) between the cutting head (1) and the transfer cavity (3) to keep the end cap (204) pressed against the inner wall of the transfer cavity (3) by a spring (205). The cutting head (1) is provided with multiple sets of spirally extending guide grooves (105) on the outside, and multiple sets of cutting teeth (2) are correspondingly provided on the inside of the guide grooves (105). The cutting head (1) includes a conical part that accommodates the transfer cavity (3). The larger side of the conical part is connected to a cylindrical part. A support box (4) is provided on the outside of the cylindrical part. The support box (4) is a cylindrical structure. Inside the support box (4) is a transmission assembly (6) that drives the cutting head (1) to rotate. Multiple sets of auxiliary components (7) are arranged around the outside of the cylindrical part, and multiple sets of receiving holes (106) for receiving auxiliary components (7) are evenly distributed on the outer circumference of the cylindrical part. The support box (4) has an inner ring fixed on the inner side of the end away from the cutting head (1). The inner ring is surrounded by a number of transverse through-holes (401). The support box (4) has a rotating frame (402) for supporting the transmission assembly (6). The transmission assembly (6) includes a cutting shaft (601) that transversely passes through the rotating frame (402). The cutting shaft (601) and the rotating frame (402) are rotatably engaged by a thrust bearing. The cutting shaft (601) extends into the cutting head (1) and has a transmission gear (602) fixed at one end. The cutting head (1) has an internal gear ring (107) fixed on the inner side of the end of the cutting head (1). The internal gear ring (107) meshes with the transmission gear (602). Below the cutting shaft (601), there is a linkage cylinder (603) coaxially distributed with the cutting head (1). Inside the cutting head (1), there is a positioning frame (108) that supports the rotation of the linkage cylinder (603). The linkage cylinder (603) and the cutting shaft (601) are connected by a belt pulley transmission mechanism. A synchronous gear (604) is fixed outside the linkage cylinder (603). The auxiliary component (7) includes a feed shaft (701) arranged laterally in the receiving hole (106). A guide cylinder (702) extending out of the receiving hole (106) is fixed to the outside of the feed shaft (701). A spirally extending scraper (702a) is provided on the outside of the guide cylinder (702). An auxiliary gear (703) meshing with a synchronous gear (604) is fixed to the outside of the feed shaft (701). A supply pipe (301) extending out of the linkage cylinder (603) passes through the end of the transfer cavity (3). The supply pipe (301) is clearance-fitted with the linkage cylinder (603). The connection between the supply pipe (301) and the transfer cavity (3) is rotatably fitted by a sealed bearing (302). A flange (301a) is fixed to the outer end of the supply pipe (301).

2. The cantilever tunneling construction device for the tailrace tunnel of a pumped storage power station according to claim 1, characterized in that: A movable ring (206) is sleeved on the outside of the mounting cylinder (202) on the outside of the cutting head (1). The movable ring (206) rotates with the mounting cylinder (202). Multiple sets of wave-shaped breaking teeth (206a) are arranged around the outside of the movable ring (206).

3. The cantilever tunneling construction device for the tailrace tunnel of a pumped storage power station according to claim 1, characterized in that: The inner side of the cutting head (1) is provided with a number of fixed frames (102) supporting the transfer cavity (3), and the end of the cutting head (1) is transversely perforated by an end hole (103). The outer circumference of the cutting head (1) on the outer side of the end hole (103) is provided with a number of bolt holes (104).

4. The cantilever tunneling construction device for the tailrace tunnel of a pumped storage power station according to claim 3, characterized in that: A drilling section (5) is provided at the end of the cutting head (1) inside the end hole (103). The drilling section (5) includes a constraint plate (502) extending into the end hole (103). A drill bit (501) extending out of the end hole (103) of the cutting head (1) is fixed outside the constraint plate (502). Multiple sets of fixing bolts (503) with through bolt holes (104) are arranged around the outside of the constraint plate (502). The constraint plate (502) and the fixing bolts (503) are threadedly engaged to fix the constraint plate (502) and the cutting head (1).

5. The construction method of the cantilever tunneling construction device for the tailrace tunnel of a pumped storage power station according to any one of claims 1-4, characterized in that, Includes the following steps: a. Drilling and blasting is prohibited when the tailrace tunnel passes under a residential area. When cantilever tunneling is required, the cantilever tunneling machine is in place and the support box (4) is installed and fixed with the extension part of the tunneling machine. The cutting motor of the cantilever tunneling machine drives the cutting reducer to rotate. The cutting reducer drives the cutting shaft (601) to drive the transmission gear (602) to rotate. The meshing action of the transmission gear (602) and the internal gear ring (107) drives the cutting head (1) to rotate inside the support box (4). The high-speed rotating cutting head (1) and its multiple sets of cutting teeth (2) move and excavate the tunnel face. b. During the high-speed rotation of the cutting head (1) supporting the cutting teeth (2), ensure that the flange (301a) of the supply pipe (301) outside the transfer chamber (3) is connected to the water supply system, and keep the transfer chamber (3) fully loaded with water. During the process of the cutting head (1) driving the cutting teeth (2) to rotate and cut the soil layer of the tunnel face, several sets of cutting teeth (2) in contact with the tunnel face are subjected to cutting pressure. At this time, the tooth bar (201) of the cutting teeth (2) is pressed into the mounting cylinder (202). As the spring (205) compresses during the contraction, the connecting hole (201a) at the end of the toothed rod (201) is simultaneously drawn into the transfer chamber (3) during the movement of the toothed rod (201), thereby realizing the connection between the compressed toothed rod (201) and the transfer chamber (3). At this time, the water in the transfer chamber (3) enters the inner side of the toothed rod (201) along the connecting hole (201a) and sprays outward, realizing the process of spraying water to cool the cutting tooth (2) and spraying water to soften the soil layer of the contact area and reduce dust. c. When the transmission gear (602) drives the internal gear ring (107) to support the cutting head (1) in a rotating state, the cutting shaft (601) drives the linkage cylinder (603) and the synchronous gear (604) to rotate through the belt transmission mechanism. The cutting shaft (601), the cutting head (1) and the linkage cylinder (603) all rotate in the same direction. The synchronous gear (604) on the outside of the linkage cylinder (603) meshes with the auxiliary gear (703), thereby synchronously driving the auxiliary component (7) to rotate during the rotation of the cutting head (1). The guide cylinder (702) and the scraper blade (702a) are in the opposite rotation state to the cutting head (1) under the support of the feed shaft (701). Thus, the soil layer cut and scraped by the cutting head (1) is rolled and transported outward by multiple sets of scraper blades (702a) distributed around the cutting head (1).

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