A back retraction type modular pipe jacking machine with adjustable pressure

Abstract

This utility model discloses a modular pipe jacking machine with adjustable tunneling pressure and retraction capability, comprising a cutterhead, a shield body, and a power unit. The cutterhead is located at the front end of the shield body, and the power unit is located at the rear of the shield body and connected to the cutterhead. The cutterhead is configured as an overlapping cutting cutterhead and a fixed baffle that can move relative to each other. By adjusting the misalignment angle between the cutting cutterhead and the fixed baffle, the opening of the soil chamber inlet can be adjusted, thereby ensuring earth pressure balance during tunneling and ensuring construction safety when traversing high-risk strata. Furthermore, the power unit is located at the rear of the machine, achieving external power transmission, and power is transmitted through a power auger drill rod, effectively increasing the input power and torque, resulting in an overall operating power increase of more than 2 times, enabling the cutterhead to be used in various complex strata.

Description

Technical Field

[0001] This utility model relates to the field of pipe jacking machine technology, specifically to a modular pipe jacking machine with adjustable tunneling pressure and retraction capability. Background Technology

[0002] Earth pressure balance (EPB) pipe jacking machines possess excellent adaptability to geological formations and strong surface settlement control capabilities, making them a primary piece of equipment for trenchless pipe jacking construction in densely built-up areas. However, existing EPB pipe jacking machines also have several drawbacks. For instance, during EPB operations, the excavation rate is adjusted by changing the cutterhead rotation speed or the advance speed to regulate the inlet opening, which cannot directly and actively regulate the EPB balance, potentially leading to hazards in complex geological formations. Furthermore, pipe jacking machines are typically driven by a power unit mounted behind the cutterhead, which, due to limitations, results in relatively low power and torque, insufficient for long-distance jacking and ineffective handling of complex geological conditions. Additionally, the machine head cannot be retracted and can only be retrieved via a receiving shaft, making operation difficult in densely built-up areas and incurring high costs; there is also the drawback of difficulty in adjusting and correcting direction during jacking. This invention provides a modular pipe jacking machine with adjustable tunneling pressure and a retractable retrieval mechanism to solve these problems. Utility Model Content

[0003] This utility model provides a modular pipe jacking machine with adjustable tunneling pressure and retraction, which solves the problem of insufficient power, and the earth pressure balance method adopted is more flexible and has stronger applicability.

[0004] The technical solution adopted by this utility model to solve the above-mentioned technical problems is: A modular pipe jacking machine with adjustable tunneling pressure and retraction includes a cutterhead, a shield body, and a power unit. The cutterhead is located at the front end of the shield body, and the power unit is located at the rear side of the shield body and connected to the cutterhead. The cutter head includes a cutting cutter head, a fixed baffle, an adjustment mechanism, and a cutting tool. The cutting cutter head is overlapped and arranged on the front side of the fixed baffle. The cutting cutter head is connected to the fixed baffle through the adjustment mechanism. The adjustment mechanism is used to adjust the overlap angle between the cutting cutter head and the fixed baffle. The cutting tool is disposed on the cutting cutter head. Both the cutting disc and the fixed baffle are provided with soil inlet windows. The soil inlet windows on the cutting disc and the fixed baffle are staggered to form a soil inlet. The fixed baffle rotates around the central axis through an adjustment mechanism to change the angle between the soil inlet windows on the fixed baffle and the soil inlet windows on the fixed baffle, thereby adjusting the opening of the soil inlet. The adjustment range of the soil inlet is 0-45°.

[0005] Furthermore, the adjustment mechanism includes an adjustment rack and a first power device. The adjustment rack is mounted on a fixed baffle, the first power device is connected to the cutting disc, and a drive gear is provided on the output end of the first power device. The adjustment rack meshes with the drive gear.

[0006] Furthermore, the cutting tool includes a fixed cutting tool and a reaming tool. The fixed cutting tool is disposed on the surface of the cutting tool disc. The reaming tool includes a reaming head, a mounting base, and a telescopic mechanism. The cutting tool disc has a reaming groove. The mounting base is disposed in the reaming groove. The telescopic mechanism is disposed on the rear side of the cutting tool disc and connected to the mounting base. The reaming head is disposed on the mounting base.

[0007] Furthermore, the power unit includes a power auger drill rod and a drive mechanism. The drive mechanism is located at the rear end of the shield body, the power auger drill rod is installed in the shield body, the drive mechanism is connected to the rear end of the power auger drill rod and drives the power auger drill rod to rotate, and the front end of the power auger drill rod is connected to the cutterhead and drives the cutterhead to rotate.

[0008] Furthermore, the front end of the power auger drill rod is connected to the cutter head via a reducer.

[0009] Furthermore, the drive mechanism includes a jacking plate, a jacking cylinder, a jacking frame, a reducer, and a rotary drive motor. The jacking cylinder is mounted on the jacking frame, and its output end is connected to the jacking plate. The jacking plate is connected to the shield body. The rotary drive motor is mounted on the jacking frame and connected to the power auger drill rod via the reducer.

[0010] Furthermore, the shield body includes a directional tube section and a reference tube section. The directional tube section is located between the cutterhead and the reference tube section. The directional tube section includes an outer directional tube and an inner directional tube. The inner directional tube is located inside the outer directional tube. The reference tube section includes an outer reference tube and an inner reference tube. The inner reference tube is located inside the outer reference tube and is connected to the inner directional tube.

[0011] Furthermore, the reference inner tube is provided with a directional hydraulic cylinder, which is arranged at intervals along the circumference of the reference inner tube, and the reference inner tube is connected to the directional inner tube through the directional hydraulic cylinder.

[0012] Furthermore, both the directional inner tube and the reference inner tube include a spiral sleeve, a supporting moving wheel, and an inner tube. The spiral sleeve is disposed inside the inner tube, the power spiral drill rod is located in the spiral sleeve, the supporting moving wheel is disposed on the inner tube, and the inner tube contacts the directional outer tube or the reference outer tube through the supporting moving wheel.

[0013] Furthermore, the outer diameter of the cutter head is the same as the inner diameter of the directional outer tube, the outer diameter of the directional inner tube is the same as the outer diameter of the reference inner tube, and the outer diameter of the directional outer tube is the same as the outer diameter of the reference outer tube.

[0014] The beneficial effects of this utility model are as follows: The cutterhead is set as an overlapping cutting cutterhead and a fixed baffle that can move relative to each other. By adjusting the misalignment angle between the cutting cutterhead and the fixed baffle, the opening of the soil chamber inlet can be adjusted, thereby ensuring the earth pressure balance during the tunneling process and ensuring construction safety when crossing high-risk strata. By placing the power unit at the rear of the device to achieve external power and transmitting power through the power auger drill rod, the input power and torque are effectively improved, resulting in an overall working power increase of more than 2 times, enabling the cutterhead to be used in various complex formations. The use of a double-layered shield body, along with a retractable borehole reamer, enables the jacking machine head and inner pipe to be retrievable, avoiding the difficulties of dismantling using a receiving well, effectively improving construction efficiency and reducing costs. Setting up directional pipe sections enables flexible and high-precision directional adjustment of the shield body, thereby achieving real-time correction of the jacking posture during tunneling and avoiding the risks caused by accumulated deviations during the tunneling process. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the shield body connection state of this utility model; Figure 3 This is a schematic diagram of the soil inlet opening control state of this utility model; Figure 4 This is a schematic diagram of the cutter head structure of this utility model; Figure 5 A schematic diagram showing the adjustment mechanism of this utility model in various states; Figure 6 This is a cross-sectional view of the cutter head of this utility model; Figure 7 This is a schematic diagram showing the setup of the reaming tool of this utility model; Figure 8 This is a schematic diagram of the cutting disc structure of this utility model; Figure 9 This is a schematic diagram of the fixed baffle structure of this utility model; Figure 10 This is a schematic diagram of the inner tube outer wall structure of this utility model; Figure 11 This is a schematic diagram showing the configuration of the power auger drill rod of this utility model. Figure 12 This is a schematic diagram showing the connection between the directional inner tube and the reference inner tube of this utility model; Figure 13 This is a schematic diagram of the inner tube structure of this utility model; Figure 14 This is a schematic diagram of the drive mechanism of this utility model.

[0016] Reference numerals: 1. Cutterhead; 11. Cutting cutterhead; 12. Fixed baffle; 13. Adjusting mechanism; 131. Adjusting rack; 132. First power unit; 14. Cutting tool; 141. Fixed cutting tool; 142. Reaming tool; 1421. Reaming head; 1422. Mounting base; 1423. Telescopic mechanism; 2. Shield body; 21. Directional pipe section; 211. Directional outer pipe; 212. Directional inner pipe; 22. Reference pipe section; 221. Reference outer pipe; 222. Reference inner pipe; 2221. Spiral sleeve; 2222. Support moving wheel; 2223. Inner pipe; 223. Directional cylinder; 3. Power unit; 31. Power spiral drill rod; 32. Drive mechanism. Detailed Implementation

[0017] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0018] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0019] like Figure 1 , 2 As shown, a modular pipe jacking machine with adjustable tunneling pressure and retraction capability includes a cutterhead 1, a shield 2, and a power unit 3. The cutterhead 1 is located at the front end of the shield 2, and the power unit 3 is located at the rear of the shield 2 and connected to the cutterhead 1. By placing the power unit 3 at the rear, a separate design of the power unit 3 and the cutterhead 1 is achieved, resulting in more installation space for the power unit 3. This allows for greater power and torque, improving the cutting capability of the cutterhead 1. Consequently, the pipe jacking machine can be used in more complex geological formations, making it suitable for pipe curtain construction with a length of less than 100m and a pipe diameter of less than 2m, and enabling it to penetrate concrete structural obstacles. Furthermore, the adjustable earth pressure allows it to be used in various geological formations in unpressurized water environments.

[0020] This invention improves power and torque during operation by placing the power unit 3 behind the shield body 2 and using the power auger drill rod 31 for power transmission, making it more adaptable to complex geological formations. The cutterhead 1 is configured with two overlapping layers, and the opening of the inlet is adjusted by regulating the overlap angle between the cutting cutterhead 11 and the fixed baffle 12, thereby achieving active control of the soil chamber pressure balance and ensuring safety during operation. Simultaneously, the shield body 2 is configured as a combination of a directional pipe section 21 and a reference pipe section 22. Adjusting the directional pipe section 21 corrects the jacking posture during tunneling, ensuring operational accuracy. Furthermore, both the directional pipe section 21 and the reference pipe section 22 are configured as inner and outer pipes, allowing control of the headstock size and enabling backward recovery without a receiving well, saving costs and improving construction efficiency.

[0021] like Figure 3 , 4 As shown in Figures 5, 6, 7, 8, and 9, the cutterhead 1 further includes a cutting cutterhead 11, a fixed baffle 12, an adjusting mechanism 13, and a cutting tool 14. The cutting cutterhead 11 overlaps with the fixed baffle 12 and is located in front of the fixed baffle 12. The cutting cutterhead 11 is connected to the fixed baffle 12 via the adjusting mechanism 13, which is used to adjust the overlap angle between the cutting cutterhead 11 and the fixed baffle 12. The cutting tool 14 is mounted on the cutting cutterhead 11. Both the cutting cutterhead 11 and the fixed baffle 12 are mounted on the power auger drill rod 31. The cutting cutterhead 11 is fixedly connected to the power auger drill rod 31, and the fixed baffle 12 is movably connected to the power auger drill rod 31 via a bearing assembly. When adjusting the misalignment angle between the cutting cutterhead 11 and the fixed baffle 12, the action of the adjusting mechanism 13 causes the fixed baffle 12 to rotate around its central axis, resulting in relative movement between the fixed baffle 12 and the cutting cutterhead 11, thereby adjusting the opening of the soil inlet.

[0022] like Figure 3 , 8 As shown in Figure 9, both the cutting disc 11 and the fixed baffle 12 are provided with soil inlet windows. The soil inlet windows on the cutting disc 11 and the fixed baffle 12 are staggered to form a soil inlet. The fixed baffle 12 rotates around its central axis through the adjusting mechanism 13, changing the angle between the soil inlet windows on the fixed baffle 12 and the fixed baffle 12, thereby adjusting the opening of the soil inlet. The adjustment range of the soil inlet is 0-45°. In the initial state, the soil inlet windows on the cutting disc 11 and the fixed baffle 12 are completely aligned, and the opening of the soil inlet is 45°. During construction, the opening of the soil inlet is adjusted according to the soil pressure, and can be adjusted to be completely closed.

[0023] like Figure 5As shown, the adjusting mechanism 13 further includes an adjusting rack 131 and a first power device 132. The adjusting rack 131 is mounted on the fixed baffle 12 and located on the rear side of the fixed baffle 12. The first power device 132 is connected to the cutting disc 11 and is mounted on the rearward-extending disc housing of the cutting disc 11. A drive gear is provided on the output end of the first power device 132, and the adjusting rack 131 meshes with the drive gear. When adjusting the opening of the soil inlet, the machine needs to be stopped first, and then the first power device 132 is controlled to operate. The drive gear on the output shaft of the first power device 132 rotates, which drives the adjusting rack 131 on the rear side of the fixed baffle 12 to move through meshing, thereby driving the fixed baffle 12 to rotate around the central axis, thus realizing the adjustment of the opening of the soil inlet. The opening and closing adjustment of the soil inlet is realized by the forward and reverse rotation of the first power device 132.

[0024] Furthermore, in order to enable the cutter head 1 to retract, the outer diameter of the cutter head 1 is set to be the same as the inner diameter of the adjusting outer tube 211, and the cutter 14 is set as a fixed cutter 141 fixed on the cutter head 1 and a retractable reaming cutter 142. When the reaming cutter 142 is in the retracted state, the overall size of the cutter head 1 is not greater than the inner diameter of the adjusting outer tube 211, so the entire cutter head 1 can be retracted from the adjusting outer tube 211. When the reaming cutter 142 is in the extended state, it can perform reaming operations.

[0025] like Figure 4 , 6 As shown in Figure 7, the cutting tool 14 includes a fixed cutting tool 141 and a reaming tool 142. The fixed cutting tool 141 is disposed on the surface of the cutting tool disc 11. The reaming tools 142 are arranged in pairs and symmetrically. Each reaming tool 142 includes a reaming head 1421, a mounting base 1422, and a telescopic mechanism 1423. The cutting tool disc 11 has a reaming groove on its surface, which is arranged radially along the surface. Therefore, when the reaming head 1421 extends, it extends outward radially along the surface, thus achieving reaming. The mounting base 1422 is disposed in the reaming groove. The telescopic mechanism 1423 is disposed on the rear side of the cutting tool disc 11 and is connected to the mounting base 1422. The mounting base 1422 extends and retracts along the reaming groove under the drive of the telescopic mechanism 1423, thereby realizing the extension and retraction of the reaming head 1421. The reaming head 1421 is disposed on the mounting base 1422. The extension and retraction of the reaming tool 142 is achieved through the extension and retraction mechanism 1423. The extension and retraction mechanism 1423 drives the mounting base 1422 to move in the reaming groove, thereby pushing the extension and retraction of the reaming tool 142 on the mounting base 1422.

[0026] like Figure 10 , 11As shown, the shield body 2 further includes a directional pipe section 21 and a reference pipe section 22. The directional pipe section 21 is located between the cutterhead 1 and the reference pipe section 22 and is used to adjust the tunneling direction. The directional pipe section 21 is connected to the reference pipe section 22 through a directional hydraulic cylinder 223. By extending and retracting the directional hydraulic cylinder 223 at different positions, the direction of the directional pipe section 21 can be adjusted, thereby changing the tunneling direction of the directional pipe section 21 and the cutterhead 1 on it, correcting the tunneling posture, and avoiding the risk of accumulated deviation of the tunneling path.

[0027] like Figure 11 , 12 As shown in Figure 13, the directional pipe section 21 includes a directional outer pipe 211 and a directional inner pipe 212, with the inner pipe 212 housed within the outer pipe 211. The reference pipe section 22 includes a reference outer pipe 221 and a reference inner pipe 222, with the inner pipe 222 housed within the outer pipe 221 and connected to the inner pipe 212. Both the directional pipe section 21 and the reference pipe section 22 are configured as double-layered pipes. During excavation, the inner and outer pipes are locked and excavated together. After excavation is completed, the locking of the inner and outer pipes is released, leaving the outer pipe in the soil as the jacking pipe, while the inner pipe and cutterhead can be retrieved from the outer pipe. Furthermore, the retrieval does not require a receiving shaft, effectively reducing costs.

[0028] like Figure 11 , 12 As shown in Figure 13, further, the reference inner tube 222 is provided with a directional hydraulic cylinder 223. Four directional hydraulic cylinders 223 are arranged at circumferential intervals along the reference inner tube 222. The direction of the directional tube section 21 is adjusted by the different extension and retraction actions of the four directional hydraulic cylinders 223. The reference inner tube 222 is connected to the directional inner tube 212 through the directional hydraulic cylinders 223.

[0029] like Figure 11 , 12 As shown in Figure 13, further, both the directional inner tube 212 and the reference inner tube 222 include a spiral sleeve 2221, a supporting moving wheel 2222, and an inner tube 2223. The spiral sleeve 2221 is disposed inside the inner tube 2223 and is used to place the power spiral drill rod 31. The power spiral drill rod 31 is located in the spiral sleeve 2221. The supporting moving wheel 2222 is disposed on the outer wall of the inner tube 2223 and contacts the inner wall of the directional outer tube 211 or the reference outer tube 221. The inner tube 2223 contacts the directional outer tube 211 or the reference outer tube 221 through the supporting moving wheel 2222.

[0030] like Figure 1 , 14As shown, the power unit 3 includes a power auger drill rod 31 and a drive mechanism 32. The drive mechanism 32 is located at the rear end of the shield body 2, providing power to the power auger drill rod 31 and also providing power for the jacking of the shield body 2. The power auger drill rod 31 is installed in the shield body 2. The drive mechanism 32 is connected to the rear end of the power auger drill rod 31 and drives the power auger drill rod 31 to rotate. The front end of the power auger drill rod 31 is connected to the cutterhead 1. When the power auger drill rod 31 rotates, it drives the cutterhead 1 to rotate. The cutterhead 1 rotates to cut the strata and cooperates with the jacking of the shield body 2 to achieve overall tunneling.

[0031] like Figure 14 As shown, the drive mechanism 32 further includes a jacking plate, a jacking cylinder, a jacking frame, a reducer, and a rotary drive motor. The jacking cylinder is mounted on the jacking frame, and its output end is connected to the jacking plate. The jacking plate is connected to the shield body 2. The jacking cylinder pushes the jacking plate, causing it to push the shield body 2 to advance. The rotary drive motor is mounted on the jacking frame and connected to the power auger drill rod 31 through the reducer. The rotary drive motor and the jacking plate move synchronously.

[0032] Furthermore, the power spiral drill rod 31 is connected to the cutter head 1 via a reducer, and the power, torque and speed of the cutter head 1 are adjusted by the reducer.

[0033] Furthermore, the outer diameter of the cutter head 1 is the same as the inner diameter of the adjusting outer tube 211, so that the cutter head 1 can retract from the adjusting outer tube 211 and the reference outer tube 221. The outer diameter of the adjusting inner tube 212 is the same as the outer diameter of the reference inner tube 222, and the outer diameter of the adjusting outer tube 211 is the same as the outer diameter of the reference outer tube 221.

[0034] A method for using a modular pipe jacking machine with adjustable tunneling pressure and retraction capability includes the following steps: S1, Equipment Assembly: Lower each module into the well and assemble them into a whole in sequence; S2, Pipe jacking: Control the fixed baffle 12 to open the inlet to the maximum, and then start the drive mechanism 32 to carry out the jacking operation; During the tunneling process, the jacking cylinder pushes the jacking plate and drives the shield to move forward. At the same time, the rotary drive motor starts and transmits power to the power auger drill rod 31 through the reducer. The rotation of the power auger drill rod 31 drives the cutter head 1 to rotate for cutting and tunneling. The cutting and jacking of the cutter head 1 are carried out simultaneously to realize pipe jacking construction. During construction, the tunneling direction is constantly monitored, and the jacking direction is corrected by controlling the directional pipe section 21. At the same time, when hole enlargement is required, the hole enlargement tool 142 is extended to enlarge the hole. S3, Earth pressure regulation: When the earth pressure in the earth chamber is high during the tunneling process, the regulating mechanism 13 is controlled to adjust the opening of the inlet, thereby controlling the earth pressure in the earth chamber during the tunneling process. When the earth pressure in the earth chamber is high, the opening of the inlet is reduced; when the earth pressure in the earth chamber is low, the opening of the inlet is increased. S4, Equipment Recovery: After the tunneling is completed, the drive mechanism 32 is first recovered and lifted out. Then, the power auger drill rod 31 is pulled to pull the inner directional pipe 212 and the reference inner pipe 222 out of the outer directional pipe 211 and the reference outer pipe 221. At the same time, the cutterhead 1 is pulled out together. After disassembly, it is lifted out.

[0035] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A pressure-adjustable back retraction type modular jacking push bench, characterized in that: It includes a cutterhead (1), a shield body (2) and a power unit (3). The cutterhead (1) is located at the front end of the shield body (2), and the power unit (3) is located at the rear side of the shield body (2) and connected to the cutterhead (1). The cutter head (1) includes a cutting cutter head (11), a fixed baffle (12), an adjustment mechanism (13), and a cutting tool (14). The cutting cutter head (11) is stacked on the front side of the fixed baffle (12). The cutting cutter head (11) is connected to the fixed baffle (12) through the adjustment mechanism (13). The adjustment mechanism (13) is used to adjust the overlap angle between the cutting cutter head (11) and the fixed baffle (12). The cutting tool (14) is mounted on the cutting cutter head (11). Both the cutting disc (11) and the fixed baffle (12) are provided with soil inlet windows. The soil inlet windows on the cutting disc (11) and the fixed baffle (12) are staggered to form a soil inlet. The fixed baffle (12) rotates around the central axis through the adjustment mechanism (13) to change the angle of the soil inlet windows on the fixed baffle (12) and the fixed baffle (12), thereby adjusting the opening of the soil inlet. The adjustment range of the soil inlet is 0-45°.

2. A pressure-adjustable back retraction type modular pipe jacking machine according to claim 1, characterized in that: The adjustment mechanism (13) includes an adjustment rack (131) and a first power device (132). The adjustment rack (131) is mounted on a fixed baffle (12). The first power device (132) is connected to the cutting disc (11). A drive gear is provided on the output end of the first power device (132). The adjustment rack (131) meshes with the drive gear.

3. The pressure-adjustable back retraction recovery type modular pipe jacking machine according to claim 1, characterized in that: The cutting tool (14) includes a fixed cutting tool (141) and a reaming tool (142). The fixed cutting tool (141) is disposed on the surface of the cutting tool disc (11). The reaming tool (142) includes a reaming head (1421), a mounting base (1422), and a telescopic mechanism (1423). The cutting tool disc (11) has a reaming groove on its surface. The mounting base (1422) is disposed in the reaming groove. The telescopic mechanism (1423) is disposed on the rear side of the cutting tool disc (11) and connected to the mounting base (1422). The reaming head (1421) is disposed on the mounting base (1422).

4. The pressure-adjustable back retraction recovery type modular pipe jacking machine according to claim 1, characterized in that: The power unit (3) includes a power auger drill rod (31) and a drive mechanism (32). The drive mechanism (32) is located at the rear end of the shield body (2). The power auger drill rod (31) is located in the shield body (2). The drive mechanism (32) is connected to the rear end of the power auger drill rod (31) and drives the power auger drill rod (31) to rotate. The front end of the power auger drill rod (31) is connected to the cutter head (1) and drives the cutter head (1) to rotate.

5. A pressure-adjustable back retraction type modular pipe jacking machine according to claim 4, characterized in that: The front end of the power auger drill rod (31) is connected to the cutter head (1) via a speed reducer.

6. A pressure-adjustable back retraction type modular pipe jacking machine according to claim 4, characterized in that: The drive mechanism (32) includes a jacking plate, a jacking cylinder, a jacking frame, a reducer and a rotary drive motor. The jacking cylinder is mounted on the jacking frame. The output end of the jacking cylinder is connected to the jacking plate. The jacking plate is connected to the shield body (2). The rotary drive motor is mounted on the jacking frame and is connected to the power auger drill rod (31) through the reducer.

7. The pressure-adjustable back retraction recovery type modular pipe jacking machine according to claim 4, characterized in that: The shield body (2) includes a directional pipe section (21) and a reference pipe section (22). The directional pipe section (21) is located between the cutterhead (1) and the reference pipe section (22). The directional pipe section (21) includes a directional outer pipe (211) and a directional inner pipe (212). The directional inner pipe (212) is located in the directional outer pipe (211). The reference pipe section (22) includes a reference outer pipe (221) and a reference inner pipe (222). The reference inner pipe (222) is located in the reference outer pipe (221) and is connected to the directional inner pipe (212).

8. A pressure-adjustable back retraction type modular pipe jacking machine according to claim 7, characterized in that: The reference inner tube (222) is provided with a directional cylinder (223), which is arranged at intervals along the circumference of the reference inner tube (222). The reference inner tube (222) is connected to the directional inner tube (212) through the directional cylinder (223).

9. A pressure-adjustable back retraction type modular pipe jacking machine according to claim 7, characterized in that: Both the directional inner tube (212) and the reference inner tube (222) include a spiral sleeve (2221), a support moving wheel (2222), and an inner tube (2223). The spiral sleeve (2221) is located inside the inner tube (2223), the power spiral drill rod (31) is located in the spiral sleeve (2221), the support moving wheel (2222) is located on the inner tube (2223), and the inner tube (2223) contacts the directional outer tube (211) or the reference outer tube (221) through the support moving wheel (2222).

10. The pressure-adjustable back retraction recovery type modular pipe jacking machine according to claim 7, characterized in that: The outer diameter of the cutter head (1) is the same as the inner diameter of the adjusting outer tube (211), the outer diameter of the adjusting inner tube (212) is the same as the outer diameter of the reference inner tube (222), and the outer diameter of the adjusting outer tube (211) is the same as the outer diameter of the reference outer tube (221).

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