A hollow pipe jacking machine for trenchless municipal pipeline expansion and a construction method

Abstract

The application discloses a hollow jacking pipe machine for non-excavation capacity expansion of municipal pipelines, which comprises an inner pipe body and an outer pipe body arranged coaxially, wherein the old pipeline passes through the inner pipe body during construction; a transmission bearing is arranged in the cavity between the inner pipe body and the outer pipe body, the transmission bearing divides the cavity into a first cavity and a second cavity which are not communicated with each other, and the rear end of the second cavity is closed; a plurality of cutting cutter heads are arranged on the front end of the first cavity in a circumferential interval, and the inner end of the cutting cutter head is fixed to the outer wall of the inner pipe body; a water distribution chamber and a slurry chamber are further arranged in the first cavity; a transmission mechanism is arranged in the second cavity, and the transmission mechanism drives the inner pipe body to rotate, and the cutting cutter head fixed to the outer wall of the inner pipe body rotates with the inner pipe body. The hollow jacking pipe machine has the beneficial effects that the main components of the hollow jacking pipe machine are arranged between the inner pipe body and the outer pipe body and are fixed to the outer wall of the inner pipe body, the pipe diameter of the outer pipe body is not limited, can be adjusted according to the required capacity expansion pipe diameter, the capacity expansion multiple is not limited, and the existing pipeline can be expanded and upgraded under the non-excavation condition.

Description

Technical Field

[0001] This invention relates to the field of trenchless construction technology for municipal drainage pipelines, specifically to a hollow pipe jacking machine and construction method for trenchless expansion of municipal pipelines. Background Technology

[0002] Currently, urban drainage pipelines are becoming increasingly sophisticated. However, after a certain number of years of use, most pipelines are unable to meet the growing demand for flow. Therefore, it is necessary to expand and upgrade the municipal drainage pipelines.

[0003] Trenchless technology, as a construction method with good socio-economic benefits, is increasingly used in municipal pipeline construction. The main method for trenchless capacity expansion is the pipe-breaking method. This method involves breaking up existing old pipelines and replacing them with new pipelines of the same or larger diameter. However, this method has drawbacks, including limited pipe diameter expansion range, easy road bulging during construction, and potential compression of adjacent pipelines. It is also unsuitable for situations where the old pipe is reinforced concrete, and the new pipe's outer wall is prone to scratches during construction. Therefore, there is an urgent need for new trenchless capacity expansion machinery for municipal pipelines and its application method to solve these problems. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a hollow pipe jacking machine and construction method for trenchless expansion of municipal pipelines with unlimited pipe diameter.

[0005] The technical solution adopted in this invention is as follows: A hollow pipe jacking machine for trenchless expansion of municipal pipelines includes an inner pipe and an outer pipe arranged coaxially. During construction, the old pipeline passes through the inner pipe. A transmission bearing is installed in the cavity between the inner and outer pipes, which divides the cavity into a first cavity and a second cavity that are not interconnected. The rear end of the second cavity is closed. The front end of the first cavity is provided with several circumferentially spaced cutting discs, the inner end of which is fixed to the outer wall of the inner pipe. The first cavity is also provided with a water distribution chamber and a mud-water chamber. The water distribution chamber is connected to one end of the water inlet pipe, and the mud-water chamber is connected to the mud-water pipe. The other ends of the water inlet pipe and the mud-water pipe pass through the transmission bearing and the second cavity and are led out to be connected to an external mud-water circulation system. The second cavity is provided with a transmission mechanism. The output end of the transmission mechanism is connected to the outer wall of the inner pipe. The transmission mechanism drives the inner pipe to rotate, and the cutting discs fixed to the outer wall of the inner pipe rotate accordingly to cut the soil.

[0006] According to the above scheme, the transmission bearing is located between the inner and outer tubes. The transmission bearing includes a convex inner ring, a concave outer ring, and balls A. The convex inner ring is connected to the inner tube; the concave outer ring is adapted to the outer tube; the concave outer ring has a groove, and the convex inner ring is inserted into the groove of the concave outer ring. Multiple rows of balls A are installed on the three sides of the convex inner ring and the concave outer ring that are in contact. Both the convex inner ring and the concave outer ring have concave guide rails for the balls A to roll, and each row of balls A is embedded in the concave guide rail.

[0007] According to the above scheme, the cutting disc is fan-shaped, and the cutting disc is provided with cutting blades and hobs. The cutting blades are spaced apart on both sides of the cutting disc, and the hobs are spaced apart in the middle of the cutting disc.

[0008] According to the above scheme, the water distribution chamber is an annular cavity structure with a conical cross-section, formed by a conical water distribution hopper fixed to the inner wall of the outer pipe; a gap is left between the outer wall of the water distribution hopper and the outer wall of the inner pipe to form a channel for mud to enter the mud-water chamber;

[0009] The water distribution hopper has evenly distributed circular water distribution holes, which are located on the 35-degree side of the outer wall of the water distribution hopper. A water inlet pipe is connected to the rear wall of the water distribution hopper, extending to the tail end of the hollow pipe jacking machine to circulate with the external mud and water.

[0010] The ring equipment is connected to the water inlet pipe.

[0011] According to the above scheme, the mud-water chamber is located at the rear of the water distribution chamber and is enclosed by the rear wall of the water distribution chamber, the outer wall of the inner pipe, the inner wall of the outer pipe, and the front side of the transmission bearing; an agitator is installed in the mud-water chamber to further mix the mud entering the mud-water chamber, so as to facilitate the transportation of the mud; the agitator is evenly distributed along the circumference.

[0012] 40. According to the above scheme, both the inner tube and the outer tube are split structures, and the inner tube is composed of a front section and a rear section connected together.

[0013] The two sections are connected, forming a turning gap; the outer tube is composed of a front section and a rear section, with a turning gap at their connection, and the two turning gaps are positioned correspondingly; the cutting disc, transmission bearing, and transmission mechanism are all located within the cavity between the front sections of the inner and outer tubes; a correction mechanism is provided within the cavity between the two turning gaps; a laser emitter is located at the end of the cavity.

[0014] The device, a laser emitter, works in conjunction with an external laser receiver. The laser emitter emits laser light parallel to the axes of the inner and outer tubes. 45. According to the above scheme, the correction mechanism includes several circumferentially spaced correction units, each correction unit comprising correction...

[0015] The hydraulic cylinder and two support plates arranged along the axial direction are provided. The two ends of the hydraulic cylinder are connected to the two support plates respectively. The two ends of one support plate are connected to the outer wall of the front section of the inner tube and the inner wall of the front section of the outer tube respectively. The two ends of the other support plate are connected to the outer wall of the rear section of the inner tube and the inner wall of the rear section of the outer tube respectively.

[0016] According to the above scheme, the second cavity is provided with an annular thixotropic mud pipe. The thixotropic mud pipe includes a thixotropic mud ring pipe, a 50 thixotropic mud main pipe, and a thixotropic mud short pipe. The thixotropic mud ring pipe is installed on the outer wall of the inner pipe body and connected to one end of the thixotropic mud ring pipe. The other end of the thixotropic mud ring pipe extends axially out of the end of the second cavity and is connected to the external thixotropic mud circulation system.

[0017] According to the above scheme, the transmission mechanism includes a drive motor, a first transmission gear, and a second transmission gear, wherein the drive motor is fixed.

[0018] The motor shaft of the drive motor is connected to the first transmission gear, which is fixed to the inner wall of the outer tube. The first transmission gear meshes with the second transmission gear 55, and the second transmission gear is installed on the outer wall of the inner tube.

[0019] This invention also provides a construction method for trenchless pipeline expansion based on the hollow pipe jacking machine described above, characterized in that the method includes the following steps:

[0020] Step 1: Construction Preparation: Divert water flow, dredge the pipeline, excavate working pits at both ends of the section to be expanded, and install the aforementioned...

[0021] Hollow pipe jacking machine;

[0022] Step 2: Cut the old pipe into multiple short sections;

[0023] Step 3: The hollow pipe jacking machine advances forward, with each advance distance being the length of a short pipe section. During the jacking process, the hollow pipe jacking machine only cuts the soil around the old pipe, and the old pipe passes through the inside of the hollow pipe jacking machine.

[0024] Step 4: After jacking in a short section of pipe, push or pull the old pipe out from inside the hollow pipe jacking machine, transport the old pipe from the new pipe to the working shaft, and hoist it out.

[0025] Step 5: For every short section of pipe that the hollow pipe jacking machine advances forward, a new section of pipe is simultaneously jacked up from behind the machine. The length of the new pipe is the same as the length of the old pipe after it has been cut.

[0026] Step Six: By continuously repeating steps Three through Six, the expansion of the old pipeline can be completed, forming a new expanded pipeline section.

[0027] Step 7: Site Restoration: Remove the construction diversion, convert the work pit into an inspection well, and restore the road surface.

[0028] The beneficial effects of this invention are as follows:

[0029] 1. The beneficial effects of the present invention are as follows: The main components of the hollow pipe jacking machine of the present invention are installed between the inner and outer pipe bodies and fixed to the outer wall of the inner pipe body. The diameter of the outer pipe body is not limited and can be adjusted according to the required expansion pipe diameter. The expansion ratio is not limited and can realize the expansion and upgrading of existing pipelines under trenchless conditions.

[0030] 2. Compared with the pipe bursting method, the present invention can design the outer pipe diameter of the hollow pipe jacking machine according to the actual pipe diameter after expansion, so that it is only slightly larger than the pipe diameter after expansion. During construction, the impact on surrounding pipelines is small and it is not easy to cause road uplift.

[0031] 3. This invention does not cut the old pipeline, but only the soil around the old pipeline. Therefore, it has low requirements for the material of the cutting head and no requirements for the material of the existing pipeline, making it widely applicable.

[0032] 4. Compared with the pipe-breaking method, in the construction process of this invention, the outer wall of the new pipe only rubs against the surrounding soil and will not rub against the broken old pipe. Therefore, it will not cause wear on the outer wall of the new pipe, and no scratches will appear on the outer wall of the new pipe, effectively ensuring the construction quality. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of a specific embodiment of the present invention.

[0034] Figure 2 This is an internal schematic diagram of this embodiment.

[0035] Figure 3 This is an axial sectional view of this embodiment.

[0036] Figure 4 This is a schematic diagram of the working state of this embodiment.

[0037] Figure 5 This is a schematic diagram of the cutting tool head.

[0038] Figure 6 This is a schematic diagram showing the position of the cutting tool head.

[0039] Figure 7 This is a three-dimensional schematic diagram of the cutting tool head.

[0040] Figure 8 This is a schematic diagram of the cross-section of the water distribution chamber.

[0041] Figure 9 This is a schematic diagram of the water distribution room and the water inlet pipe.

[0042] Figure 10 This is a schematic diagram of the cross-section of the mud-water chamber.

[0043] Figure 11 This is a schematic diagram of the mud-water chamber, mixing paddle, and mud-water pipe.

[0044] Figure 12 This is a schematic diagram of the meshing of the transmission mechanism.

[0045] Figure 13 This is a schematic diagram of the cross-section of a thixotropic mud pipe.

[0046] Figure 14 This is a schematic diagram showing the location of the thixotropic mud pipes.

[0047] Figure 15 This is a schematic diagram of the support plate and the correction cylinder.

[0048] Figure 16 This is a schematic diagram of a transmission bearing.

[0049] Figure 17 This is a schematic diagram of a sealed bearing.

[0050] Figure 18 This is a schematic diagram of steering clearance.

[0051] In the diagram, 1. Old pipe; 2. New pipe; 3. Outer pipe body; 4. Inner pipe body; 5. Cutting disc; 5-1. Cutting blade; 5-2. Hob; 6. Water distribution chamber; 6-1. Water distribution hopper; 6-2. Water distribution hole; 7. Slurry chamber; 8. Agitator; 9. Transmission bearing; 9-1. Convex inner ring; 9-2. Concave outer ring; 9-3. Ball bearing A; 9-4. Rotating sealing washer A; 10. First transmission gear; 11. Second transmission gear; 12. Drive motor; 13. Inlet pipe; 14. 15. Thixotropic mud pipe; 15-1. Thixotropic mud main pipe; 15-2. Thixotropic mud ring pipe; 15-3. Thixotropic mud short pipe; 16. Sealed bearing; 16-1. Folded clearance B; 16-2. Ball bearing B; 16-3. Waterproof brush; 16-4. Rotating sealing washer B; 17. Turning clearance; 17-1. Folded clearance C; 17-2. Sealing washer; 18. Support plate; 19. Correction cylinder; 20. Laser emitter; 21. Annular right-angle top iron. Detailed Implementation

[0052] To better understand the present invention, the invention will be further described below with reference to the accompanying drawings and embodiments.

[0053] like Figures 1-4The hollow pipe jacking machine shown includes an inner pipe body 4 and an outer pipe body 3 arranged coaxially. The inner diameter of the inner pipe body 4 is larger than the outer diameter of the old pipe 1. During construction, the old pipe 1 passes through the inner pipe body 4. A transmission bearing 9 is installed in the cavity between the inner and outer pipe bodies 3, which divides the cavity into a first cavity and a second cavity that are not connected to each other. The rear end of the second cavity is closed. The front end of the first cavity is provided with several circumferentially spaced cutting discs 5. The inner end of the cutting discs 5 is flush with the outer wall of the inner pipe body 4. Fixed; the first cavity is also provided with a water distribution chamber 6 and a mud water chamber 7. The water distribution chamber 6 is connected to one end of the water inlet pipe 13, and the mud water chamber 7 is connected to the mud water pipe 14. The other ends of the water inlet pipe 13 and the mud water pipe 14 pass through the transmission bearing 9 and the second cavity and are led out to be connected to the external mud water circulation system; the second cavity is provided with a transmission mechanism. The output end of the transmission mechanism is connected to the outer wall of the inner tube 4. The transmission mechanism drives the inner tube 4 to rotate, and the cutting disc 5 fixed to the outer wall of the inner tube 4 rotates accordingly to cut the soil.

[0054] In this invention, the inner diameter of the inner pipe 4 is 1-2 cm larger than the outer diameter of the old pipe 1, and the outer diameter of the outer pipe 3 is 1-2 cm larger than the outer diameter of the new pipe 2. The transmission bearing 9 is used to ensure the fixed position of the cutting disc 5 during rotation and to transmit the forward jacking force. The water inlet pipe 13 and the mud water pipe 14 extend from the tail of the hollow pipe jacking machine and connect to the external mud water circulation system for discharging the cut soil.

[0055] Preferably, such as Figure 16 As shown, the transmission bearing 9 is located between the inner and outer tubes 3. The transmission bearing 9 includes a convex inner ring 9-1, a concave outer ring 9-2, and balls A9-3. The convex inner ring 9-1 is connected to the inner tube 4; the concave outer ring 9-2 is connected to the outer tube 3; the concave outer ring 9-2 has a groove, and the convex inner ring 9-1 is inserted into the groove of the concave outer ring 9-2. Multiple rows of balls A9-3 are installed on the three sides of the convex inner ring 9-1 and the concave outer ring 9-2 that are in contact with each other. Concave guide rails for the balls A9-3 to roll are stored on both the convex inner ring 9-1 and the concave outer ring 9-2. Each row of balls A9-3 is embedded in the concave guide rail.

[0056] In this invention, the concave outer ring 9-2 of the transmission bearing 9 is connected to the outer tube 3. The front and rear walls of the concave end of the concave outer ring 9-2 are tightly attached to the outer wall of the inner tube 4, with a certain gap. Double-row rotating sealing washers A9-4 are installed in the gap. The gaps between the double-row rotating sealing washers A9-4 and between the convex inner ring 9-1 and the concave outer ring 9-2 of the transmission bearing 9 are filled with lubricating oil, which plays a role in lubrication and sealing and waterproofing.

[0057] 130 In this invention, the convex inner ring 9-1 of the transmission bearing 9 is connected to the inner tube 4, and the inner tube 4 is further connected to the inner wall of the cutting disc 5, thereby restricting the axial position of the cutting disc 5 so that it cannot move axially but can only rotate around the axis.

[0058] The ball bearing A9-3 is used to reduce the resistance during rotation. At the same time, the transmission bearing 9 transmits the jacking force from the rear of the hollow tube jacking machine through the concave outer ring 9-2, the ball bearing A9-3, the convex inner ring 9-1 and the inner tube body 4, and finally to the cutting disc 5 for it to jack forward. This allows the cutting disc 5 to move forward and rotate simultaneously during the jacking process. The water inlet pipe 13 and the mud water pipe 14135 pass through the concave outer ring 9-2 of the transmission bearing 9.

[0059] Preferably, such as Figure 12 As shown, the transmission mechanism includes a drive motor 12, a first transmission gear 10, and a second transmission gear 11. The drive motor 12 is fixed to the inner wall of the outer tube 3. The motor shaft of the drive motor 12 is connected to the first transmission gear 10. The first transmission gear 10 meshes with the second transmission gear 11. The second transmission gear 11 is installed on the outer wall of the inner tube 4.

[0060] In this embodiment, there are at least three drive motors 12 and corresponding first transmission gears 10, evenly distributed circumferentially, and only one second transmission gear 11, fixed around the outer circumference of the inner tube 4. The second transmission gear 11 is slightly wider than the width of the first transmission gear 10, and the first transmission gear 10 meshes with the second transmission gear 11. The drive motor 12 is installed on the inner wall of the outer tube 3. The motor shaft of the drive motor 12 drives the first transmission gear 10 to rotate, and the second transmission gear 11 meshing with the first transmission gear 10 drives the inner tube 4 to rotate accordingly. The cutting disc 5 located at the front end of the inner tube 4 rotates to cut the soil.

[0061] Preferably, such as Figures 5-7 As shown, the cutting disc 5 is fan-shaped, and is equipped with cutters 5-1 and hobs 5-2. The cutters 5-1 are spaced apart on both sides of the cutting disc 5, with at least one row on each side; the hobs 5-2 are spaced apart in the center of the cutting disc 5, with at least one row. The hobs 5-2 and cutters 5-1 are symmetrically distributed along the centerline of the disc, with at least one cutter 5-1 on each side close to the outer tube 3 and at least one close to the inner tube 4. The cutter 5-1 has a "mountain-shaped" protruding structure.

[0062] The hob 5-2 is cylindrical with irregularly shaped protrusions evenly distributed on its surface. The cutting disc 5 has tapered bevels on both sides to facilitate cutting the soil.

[0063] 150 In this invention, a gap is left between the outer end of the cutting disc 5 and the inner wall of the outer tube 3 to facilitate rotation while restricting it.

[0064] The cutting tool is used to cut the soil. There are no fewer than 6 cutting tool discs 5, which are evenly spaced along the circumference. The gap between two adjacent cutting tool discs 5 is used for the cut soil to enter the mud-water chamber 7.

[0065] Preferably, such as Figure 8 and 9 As shown, the water distribution chamber 6 is an annular cavity structure with a conical cross-section, formed by a conical water distribution hopper 6-1 fixed to the inner wall of the outer pipe body 3. A gap is left between the outer wall of the water distribution hopper 6-1 and the outer wall of the inner pipe body 4, forming a channel for the mud to enter the mud-water chamber 7. Circular water distribution holes 6-2 are evenly distributed on the water distribution hopper 6-1, with no fewer than 12 holes evenly distributed circumferentially. The water distribution holes 6-2 are located on the side of the water distribution hopper 6-1 closest to the outer wall. A water inlet pipe 13 is connected to the rear wall of the water distribution hopper 6-1, extending to the tail of the hollow pipe jacking machine and connecting to the water inlet pipe 13 of the external mud-water circulation equipment.

[0066] In this invention, clean water enters the water distribution hopper 6-1 from the water inlet pipe 13 and is then sprayed out from the water distribution hole 6-2 on the water distribution hopper 6-1. The cut soil is in front of the water distribution hopper 6-1 and is initially mixed with the clean water sprayed from the water distribution hole 6-2. Then, it enters the mud-water chamber 7 through the channel between the water distribution hopper 6-1 and the outer wall of the inner pipe. The conical shape of the water distribution hopper 6-1 helps the initially mixed mud to enter the mud-water chamber 7.

[0067] Preferably, such as Figure 10 and 11 As shown, the mud-water chamber 7 is located at the rear of the water distribution chamber 6, and is enclosed by the rear wall of the water distribution chamber 6, the outer wall of the inner pipe 4, the inner wall of the outer pipe 3, and the front side of the transmission bearing 9. An agitator 8 is installed inside the mud-water chamber 7 to further mix the mud entering the chamber, facilitating mud transport; the agitator 8 is evenly distributed circumferentially, with no fewer than six agitators. The mud-water chamber 7 is connected to a mud-water pipe 14, which passes through the transmission bearing 9 and extends to the tail end of the hollow pipe jacking machine, connecting to the external mud-water circulation equipment. Mud and water enter the mud-water pipe 14 from the mud-water chamber 7 and are discharged through the external mud-water circulation equipment.

[0068] Preferably, the second cavity is provided with an annular thixotropic mud pipe 15, such as... Figure 13 and 14 As shown, the thixotropic mud pipe 15 includes a thixotropic mud ring pipe 15-2, a thixotropic mud main pipe 15-1, and a thixotropic mud short pipe 15-3. The thixotropic mud ring pipe 15-2 is installed on the outer wall of the inner pipe body 4 and is connected to one end of the inner pipe body 4. The other end of the thixotropic mud ring pipe 15-2 extends axially through the end of the second cavity and is connected to the external thixotropic mud circulation system.

[0069] In this invention, the outer wall of the outer pipe body 3 is provided with mounting holes for installing thixotropic mud slurry short tubes 15-3. The thixotropic mud slurry short tubes 15-3 are inserted into the mounting holes, with their ends flush with the outer wall of the outer pipe body 3; the number of thixotropic mud slurry short tubes 15-3 is not less than 6. The thixotropic mud slurry circulation system supplies mud to the thixotropic mud slurry pipe 15. The mud passes through the thixotropic mud slurry main pipe 15-1, the thixotropic mud slurry ring pipe 15-2, and then is sprayed out to the outside of the outer pipe body 3 through the thixotropic mud slurry short tubes 15-3, reducing the frictional resistance of the outer wall of the hollow pipe jacking machine.

[0070] Preferably, both the inner tube 4 and the outer tube 3 are split structures. The inner tube 4 is formed by connecting a front section and a rear section of the inner tube, with a steering clearance 17 (which can be an inner steering clearance) at the connection point. The outer tube 3 is formed by connecting a front section and a rear section of the outer tube, with a steering clearance 17 (which can be an outer steering clearance) at the connection point. The two steering clearances 17 are positioned correspondingly, such as... Figure 18 As shown; a correction mechanism is provided in the cavity between the two steering clearances 17; a laser emitter 20 is provided at the end of the cavity, which cooperates with an external laser receiver, and can emit laser light parallel to the axis of the inner and outer tubes 3. The cutting disc 5, the transmission bearing 9, and the transmission mechanism are all located in the cavity between the front section of the inner tube and the front section of the outer tube.

[0071] In this invention, the turning gap 17 is a right-angle folded gap 17-1, with 1 to 2 rows of sealing gaskets 17-2 inside. The turning gap 17 allows the front and rear sections of the inner and outer tubes 3 to deflect under the action of the correction mechanism for correction and turning. The laser emitter 20, by emitting laser light and cooperating with an external laser receiver, determines whether the jacking direction is the predetermined direction, thereby determining whether correction is needed and the correction angle.

[0072] Preferably, such as Figure 15 As shown, the correction mechanism includes several correction units distributed circumferentially. Each correction unit includes a correction cylinder 19 and two support plates 18 arranged axially. The two ends of the correction cylinder 19 are respectively connected to the two support plates 18. The two ends of one support plate 18 are respectively connected to the outer wall of the front section of the inner tube and the inner wall of the front section of the outer tube, and the two ends of the other support plate 18 are respectively connected to the outer wall of the rear section of the inner tube and the inner wall of the rear section of the outer tube.

[0073] In this invention, the support plates 18 are connected between the inner and outer walls, evenly distributed along the circumference in a double-row arrangement, with no fewer than 8 support plates 18 in each row. Between the double rows of support plates 18, correction cylinders 19 can be installed, with no fewer than 4 correction cylinders evenly distributed along the circumference. For example, when the machine head is disturbed and deflects to the left, the left correction cylinder extends, while the right correction cylinder remains stationary or retracts, thereby driving the machine head to deflect back to the right. Using correction cylinders to correct the machine head is a mature existing technology and will not be elaborated upon here. The correction cylinders 19 can be used to control the deflection direction of the pipe jacking machine head, and also, together with the double rows of support plates 18, to transmit the jacking force from the rear part of the pipe jacking machine forward to the front and middle parts of the machine.

[0074] Preferably, the front section of the inner tube includes a first inner tube section and a second inner tube section connected by a sealed bearing 16. The second transmission gear 11 of the transmission mechanism is mounted on the first inner tube section, driving the first inner tube section to rotate, thereby driving the cutting disc 5 to rotate.

[0075] In this invention, a folded gap 16-1 is formed between the first inner pipe section and the second inner pipe section; as shown... Figure 17 As shown, the sealed bearing 16 is generally in the shape of a right-angled zigzag line, including ball bearings B16-2, rotating sealing washers B16-4, and waterproof brushes 16-3. There are at least two rows of ball bearings B16-2. The waterproof brushes 16-3 are located at the edge of the zigzag gap 16-1, flush with the outer side of the inner tube 4. The zigzag gap 16-1 is filled with lubricating oil, serving a sealing and waterproof function. The sealed bearing 16 is a mature existing structure and will not be described in detail here.

[0076] 205 Preferably, an annular right-angle top iron 21 is installed on the outer side of the rear end of the second cavity. The outer wall of the annular right-angle top iron 21 is flush with the outer wall of the outer pipe 3, and the inner diameter of the annular right-angle top iron 21 is 1-2 cm larger than the outer diameter of the new pipe 2.

[0077] A construction method for trenchless pipeline expansion based on the hollow pipe jacking machine described above, the method comprising the following steps:

[0078] Step 1, Construction Preparation: Construction diversion, pipeline dredging, excavation of working pits at both ends of the pipe section to be expanded, and installation of the hollow pipe jacking machine;

[0079] Step 210: Use specialized equipment to cut the old pipe into multiple short sections of suitable length.

[0080] Step 3: The hollow pipe jacking machine advances forward, with each advance distance being one short pipe section. During the jacking process, the hollow pipe jacking machine only cuts the soil around the old pipe 1, while the old pipe 1 passes through the inside of the hollow pipe jacking machine.

[0081] Step 4: After jacking in a short section of pipe, use special equipment to push or pull the old pipe 1 out from inside the hollow pipe jacking machine, transport the old pipe 1 from the new pipe 2 to the working shaft, and hoist it out.

[0082] Step 5 of 215: For every short section of pipe that the hollow pipe jacking machine advances forward, a new section of pipe is simultaneously jacked up from behind the machine. The length of the new pipe is the same as the length of the old pipe after it has been cut.

[0083] Step 6: By continuously repeating steps 3 to 6, the expansion of the old pipeline 1 can be completed, forming a new pipeline segment after expansion.

[0084] Step 7: Site Restoration: Remove the construction diversion, convert the work pit into an inspection well, and restore the road surface.

[0085] The above are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent changes made in accordance with the claims of the present invention are still within the scope of protection of the present invention.

Claims

1. A hollow pipe jacking machine for trenchless expansion of municipal pipelines, characterized in that, The system comprises an inner and outer pipe body arranged coaxially. The inner diameter of the inner pipe body is larger than the outer diameter of the old pipe, allowing the old pipe to pass through the inner pipe body during construction. A transmission bearing is installed in the cavity between the inner and outer pipe bodies, dividing the cavity into a first and a second cavity that are not interconnected. The rear end of the second cavity is closed. The front end of the first cavity is provided with several circumferentially spaced cutting discs, the inner ends of which are fixed to the outer wall of the inner pipe body. The first cavity also contains a water distribution chamber and a mud-water chamber. The water distribution chamber is connected to one end of the water inlet pipe, and the mud-water chamber is connected to the mud-water pipe. The other ends of the water inlet pipe and the mud-water pipe pass through the transmission bearing and the second cavity and are led out to connect to an external mud-water circulation system. The second cavity contains a transmission mechanism, the output end of which is connected to the outer wall of the inner pipe body. The transmission mechanism drives the inner pipe body to rotate, causing the cutting discs fixed to the outer wall of the inner pipe body to rotate accordingly, cutting the soil. The transmission bearing is located between the inner and outer tubes. The transmission bearing includes a convex inner ring, a concave outer ring, and balls A. The convex inner ring is connected to the inner tube; the concave outer ring is connected to the outer tube; the concave outer ring has a groove, and the convex inner ring is inserted into the groove of the concave outer ring. Multiple rows of balls A are installed on the three sides of the convex inner ring and the concave outer ring that are in contact. Both the convex inner ring and the concave outer ring have concave guide rails for the balls A to roll, and each row of balls is embedded in the concave guide rail. The water distribution chamber is an annular cavity structure with a conical cross-section, formed by a conical water distribution hopper fixed to the inner wall of the outer pipe. A gap is left between the outer wall of the water distribution hopper and the outer wall of the inner pipe to form a channel for mud to enter the mud-water chamber. The water distribution hopper has evenly distributed circular water distribution holes, which are located on the side of the water distribution hopper closest to the outer wall. A water inlet pipe is connected to the rear wall of the water distribution hopper and extends to the tail of the hollow pipe jacking machine to connect with the water inlet pipe of the external mud-water circulation equipment. Both the inner and outer tubes are split structures. The inner tube is formed by connecting the front and rear sections of the inner tube, with a turning gap at the connection point. The outer tube is formed by connecting the front and rear sections of the outer tube, with a turning gap at the connection point. The two turning gaps are positioned correspondingly. The cutting disc, transmission bearing, and transmission mechanism are all located in the cavity between the front sections of the inner and outer tubes. A correction mechanism is provided in the cavity between the two turning gaps. A laser emitter is provided at the end of the cavity. The laser emitter cooperates with an external laser receiver and emits laser light parallel to the axes of the inner and outer tubes. The second cavity is provided with an annular thixotropic mud pipe, which includes a thixotropic mud ring pipe, a thixotropic mud main pipe, and a thixotropic mud short pipe. The thixotropic mud ring pipe is installed on the outer wall of the inner pipe body and connected to one end of the thixotropic mud ring pipe. The other end of the thixotropic mud ring pipe extends axially out of the end of the second cavity and is connected to the external thixotropic mud circulation system.

2. The hollow tube jacking machine as described in claim 1, characterized in that, The cutting disc is fan-shaped and equipped with cutting blades and hobs. The cutting blades are spaced apart on both sides of the cutting disc, and the hobs are spaced apart in the middle of the cutting disc.

3. The hollow tube jacking machine as described in claim 1, characterized in that, The mud-water chamber is located at the rear of the water distribution chamber and is enclosed by the rear wall of the water distribution chamber, the outer wall of the inner pipe, the inner wall of the outer pipe, and the front side of the transmission bearing. An agitator is installed in the mud-water chamber to further mix the mud entering the mud-water chamber, so as to facilitate the transportation of the mud. The agitator is evenly distributed along the circumference.

4. The hollow tube jacking machine as described in claim 1, characterized in that, The correction mechanism includes several circumferentially spaced correction units. Each correction unit includes a correction cylinder and two support plates arranged along the axial direction. The two ends of the correction cylinder are respectively connected to the two support plates. The two ends of one support plate are respectively connected to the outer wall of the front section of the inner tube and the inner wall of the front section of the outer tube, and the two ends of the other support plate are respectively connected to the outer wall of the rear section of the inner tube and the inner wall of the rear section of the outer tube.

5. The hollow tube jacking machine as described in claim 1, characterized in that, The transmission mechanism includes a drive motor, a first transmission gear, and a second transmission gear. The drive motor is fixed to the inner wall of the outer tube. The motor shaft of the drive motor is connected to the first transmission gear. The first transmission gear meshes with the second transmission gear. The second transmission gear is installed on the outer wall of the inner tube.

6. A construction method for trenchless pipeline expansion based on a hollow pipe jacking machine as described in any one of claims 1 to 5, characterized in that, The method includes the following steps: Step 1, Construction Preparation: Construction diversion, pipeline dredging, excavation of working pits at both ends of the pipe section to be expanded, and installation of the hollow pipe jacking machine; Step 2: Cut the old pipe into multiple short sections; Step 3: The hollow pipe jacking machine advances forward, with each advance distance being the length of a short pipe section. During the jacking process, the hollow pipe jacking machine only cuts the soil around the old pipe, and the old pipe passes through the inside of the hollow pipe jacking machine. Step 4: After jacking in a short section of pipe, push or pull the old pipe out from inside the hollow pipe jacking machine, transport the old pipe from the new pipe to the working shaft, and hoist it out. Step 5: For every short section of pipe that the hollow pipe jacking machine advances forward, a new section of pipe is simultaneously jacked up from behind the machine. The length of the new pipe is the same as the length of the old pipe after it has been cut. Step 6: Repeat steps 3 through 6 to complete the expansion of the old pipeline and form a new expanded pipeline section. Step 7: Site Restoration: Remove the construction diversion, convert the work pit into an inspection well, and restore the road surface.

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