A pipe jacking machine head is flexible in steering, reliable in sealing and suitable for long distance jacking

Abstract

The application discloses a pipe jacking machine head which is flexible in steering, reliable in sealing and suitable for long-distance jacking, and comprises a cutter head arranged at the front end of the machine head, a front shield arranged at the rear side of the cutter head and connected with the cutter head at the front end, a middle shield coaxially arranged at the rear side of the front shield and leaving a first steering gap between the front end and the front shield, a rear shield coaxially arranged at the rear side of the middle shield and leaving a second steering gap between the front end and the middle shield, two groups of quick-release sealing devices respectively installed at the first / second steering gap, a plurality of hydraulic steering devices evenly hingedly installed in the first steering gap to connect the front shield and the middle shield, a plurality of motor worm gear auxiliary steering devices evenly hingedly installed in the second steering gap to connect the middle shield and the rear shield, and a control device connected with the hydraulic steering devices and the motor worm gear auxiliary steering devices. The application can take into account flexible steering and reliable sealing, thereby ensuring construction efficiency and construction safety, and has obvious advantages.

Description

Technical Field

[0001] This invention relates to the field of pipe jacking machine technology, and specifically to a pipe jacking machine head that is flexible in steering, reliable in sealing, and suitable for long-distance jacking. Background Technology

[0002] With the accelerated development of urban underground space, pipe jacking technology has been widely used in the construction of subways and municipal pipeline networks due to its advantages such as minimal environmental impact and high efficiency. As a core component, the pipe jacking machine head's steering flexibility and sealing reliability directly affect construction efficiency and safety.

[0003] Currently, common pipe jacking machine heads employ a front and rear shield straight-tube butt joint structure, with the two in surface contact. The steering angle depends entirely on the pre-reserved gap between them: an excessively large gap can lead to mud and water leakage, threatening construction safety; an excessively small gap severely restricts the steering angle, making the machine head clumsy and unable to adapt to curved jacking or rapid correction, affecting construction accuracy and progress. Therefore, long-distance jacking projects urgently require a machine head design that balances flexible steering with reliable sealing.

[0004] While existing technologies have focused on improving the stability of hydraulic steering systems or optimizing sealing structures, significant shortcomings remain: firstly, limitations imposed by the underlying structure restrict the improvement in steering flexibility; secondly, the complex design of sealing components makes disassembly and maintenance time-consuming and labor-intensive, severely reducing the continuity and efficiency of construction. How to collaboratively address the three major issues of steering flexibility, reliable sealing, and convenient maintenance has become crucial for technological breakthroughs in the industry.

[0005] It is understood that the above statements only provide background information related to the present invention and do not necessarily constitute prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a pipe jacking machine head that is flexible in steering, reliable in sealing, and suitable for long-distance jacking, so as to ensure both flexible steering and reliable sealing, thereby ensuring construction efficiency and construction safety.

[0007] To achieve the above objectives, the present invention provides a pipe jacking machine head, comprising: a cutterhead disposed at the foremost end of the pipe jacking machine head; a front shield, a cylindrical pressure-bearing structure disposed on the rear side of the cutterhead, with its front end connected to the cutterhead; a middle shield, a cylindrical pressure-bearing structure coaxially disposed on the rear side of the front shield, with a first turning clearance reserved between its front end and the front shield; a rear shield, a cylindrical pressure-bearing structure coaxially disposed on the rear side of the middle shield, with a second turning clearance reserved between its front end and the middle shield; and two quick-release sealing devices, respectively installed at the first turning clearance and the second turning clearance. To achieve dynamic sealing between adjacent shield bodies; multiple hydraulic steering devices are uniformly hinged in the first steering gap along the circumference to connect the front shield and the middle shield, driving the jacking machine head to achieve main steering action while jacking; multiple motor worm gear auxiliary steering devices are uniformly hinged in the second steering gap along the circumference to connect the middle shield and the rear shield, cooperating with the hydraulic steering devices to achieve fine adjustment of the steering angle while jacking; a control device is connected to the hydraulic steering devices and the motor worm gear auxiliary steering devices respectively to realize the jacking and steering control of the jacking machine head.

[0008] Preferably, annular grooves are respectively formed on the outer circumferential surfaces of the rear end of the front shield, the front and rear ends of the middle shield, and the front end of the rear shield; each set of quick-release sealing devices includes: O-rings, which are respectively installed in each of the annular grooves; a sealing shell, which is a split annular wrapping structure with upper and lower closed sections, including an upper half and a lower half of a semi-circular ring, and the inner surface of the sealing shell is provided with an annular sealing groove corresponding to the position of the O-ring; the sealing shell wraps around the outside of the first or second turning gap of the adjacent shield body, so that the annular groove of the shield body and the annular sealing groove of the sealing shell form an annular receiving cavity, and the O-ring is limited and accommodated in the annular cavity. The sealing shell is fitted with a rectangular elastic sealing ring, the thickness of which is greater than the total radial height of the annular cavity to form a radial seal. A rectangular elastic sealing ring is installed at the mating surfaces of the upper and lower halves of the sealing shell. Corresponding rectangular sealing grooves are provided on the mating surfaces of both the upper and lower halves of the sealing shell. The rectangular sealing grooves of the upper and lower halves enclose a rectangular cavity, and the rectangular elastic sealing ring is contained within this rectangular cavity. The thickness of the rectangular elastic sealing ring is greater than the total groove depth of the rectangular cavity to form an axial seal. Connecting members are arranged at equal intervals along the mating surface direction of the sealing shell to lock the upper and lower halves of the sealing shell.

[0009] Preferably, the connector includes multiple sets of bolts and nuts; the part of the sealing shell that contacts the end face of the shield is made of high-hardness alloy steel, and the remaining part is made of high-strength fiber-reinforced rubber; the O-ring and the rectangular elastic sealing ring are both made of hydrogenated nitrile rubber.

[0010] Preferably, a total of four hydraulic steering devices are provided, each of which includes: a hydraulic jack and a pair of first hinge fixing bases; the four pairs of first hinge fixing bases are uniformly and symmetrically fixedly installed on the rear end face of the front shield and the front end face of the middle shield along the circumference, respectively corresponding to the upper, lower, left and right positions of the machine head; the two ends of the hydraulic jack are respectively hinged to the corresponding pair of first hinge fixing bases to adapt to the angle swing of the hydraulic jack during the steering process.

[0011] Preferably, the hydraulic jack includes: a front hydraulic fork-shaped component, a piston rod, a front cover, a piston, a hydraulic cylinder cover, a hydraulic cylinder, a rear cover, and a rear hydraulic fork-shaped component; the hydraulic cylinder is the pressure-bearing body of the hydraulic jack, and is coaxial with the central axes of the piston rod, piston, front cover, and rear cover; the front cover and rear cover are respectively sealed and installed at the front and rear ends of the hydraulic cylinder, forming a hydraulic chamber together with the hydraulic cylinder; the hydraulic cylinder cover is installed between the mating end faces of the front cover and the hydraulic cylinder, and is used to help enhance the sealing performance and assembly positioning accuracy of the front end of the hydraulic cylinder; the piston is fixed to the rear end of the piston rod and is slidably and sealed in the inner cavity of the hydraulic cylinder, dividing the hydraulic chamber into a piston rod chamber and a piston rod-free chamber; the front end of the piston rod protrudes from the front cover and is fixedly connected to the front hydraulic fork-shaped component, and the rear end of the rear cover is fixed with the rear hydraulic fork-shaped component, and the two hydraulic fork-shaped components are respectively hinged to the corresponding first hinge fixing base.

[0012] Preferably, the hydraulic jack has a built-in telescopic displacement sensor, which is communicatively connected to the control device to collect real-time information on the extension and retraction of the piston rod, thereby achieving closed-loop displacement control.

[0013] Preferably, four motor worm gear auxiliary steering devices are provided. Each motor worm gear auxiliary steering device includes a motor worm gear jack and a pair of second hinge fixing bases. The four pairs of second hinge fixing bases are uniformly and symmetrically fixedly installed on the rear end face of the middle shield and the front end face of the rear shield along the circumference, respectively corresponding to the upper, lower, left and right positions of the machine head, and corresponding one-to-one with the circumferential position of the first hinge fixing bases. The two ends of the motor worm gear jack are respectively hinged to the corresponding pair of second hinge fixing bases to adapt to the angular swing of the motor worm gear jack during the steering process.

[0014] Preferably, the motor worm gear jack includes: a front motor fork-shaped component, a motor, a worm, a worm wheel, a plunger, a motor end cover, a bearing housing, a plunger sleeve, a plunger end cover, and a rear motor fork-shaped component; the motor is fixedly installed on the front end of the plunger sleeve via the motor end cover, the worm is rotatably installed in the inner cavity of the plunger sleeve via the bearing housing, and the front end of the worm is coaxially connected to the output shaft of the motor; the worm wheel is rotatably installed in the inner cavity of the plunger sleeve and meshes with the worm for transmission; the plunger is disposed in the inner cavity of the plunger sleeve, and its front end engages with the internal thread of the worm wheel; the motor end cover and the plunger end cover are respectively sealed and installed on the front end of the motor and the rear end of the plunger sleeve; the front motor fork-shaped component is fixed to the front end of the motor end cover, and the rear motor fork-shaped component is fixed to the rear end of the plunger end cover, and the two motor fork-shaped components are respectively hinged to the corresponding second hinge fixing base.

[0015] Preferably, the control device includes: multiple control units, respectively installed on the first hinge fixing base and the second hinge fixing base, corresponding one-to-one with each hydraulic jack and motor worm gear jack, for transmitting telescoping information in real time; and a controller, installed inside the rear shield, communicating with each control unit, the hydraulic steering device, and the motor worm gear auxiliary steering device, for coordinating and controlling the hydraulic steering device and the motor worm gear auxiliary steering device according to the actual posture and telescoping information of the pipe jacking machine head.

[0016] Preferably, the front cavity of the front shield is equipped with a main drive motor and reducer for driving the cutter head; the rear cavity of the middle shield integrates a lubricating oil pump and a cooling water tank, the lubricating oil circuit extends from the lubricating oil pump to each moving part to provide continuous forced lubrication, the inlet and outlet of the cooling water tank are both connected to cooling pipes to form a complete closed-loop cooling circuit, and the cooling pipes are arranged around the outside of each heat-generating part to achieve closed-loop temperature control; the electrical devices of the pipe jacking machine head are connected to an external box-type transformer for power supply through a distribution cabinet.

[0017] In summary, compared with the prior art, the present invention provides a flexible, reliable, and long-distance jacking machine head that is suitable for long-distance jacking. It adopts a split-type quick-release double sealing structure, which ensures flexible large-angle turning between shield bodies while achieving dynamic and reliable sealing across the entire turning angle range, and significantly reduces the difficulty of downhole maintenance. At the same time, it also adopts a two-stage coordinated steering system with hydraulic main steering and motor worm gear assisted steering, which has the functions of large-angle rapid correction, micron-level precise fine adjustment, and reverse self-locking attitude maintenance. The steering control is flexible and highly accurate, and has significant practical value. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the pipe jacking machine head in this invention; Figure 2This is a schematic diagram of the connection between the upper and lower sealing shells in the quick-release sealing device of the present invention; Figure 3 This is a schematic diagram of the connection between the upper and lower sealing shells in the quick-release sealing device of the present invention; Figure 4 This is a schematic diagram of the hydraulic jack structure in this invention; Figure 5 This is a schematic diagram of the motor worm gear jack structure in this invention; Figure 6 This is a schematic diagram of the connection between the upper and lower sealing shells in a quick-release sealing device according to another embodiment of the present invention; Figure 7 This is a schematic diagram of the connection between the upper and lower sealing shells in a quick-release sealing device according to another embodiment of the present invention.

[0019] In the picture: 1-Cutterhead, 2-Front shield, 3-Middle shield, 4-Rear shield, 5-Quick-release sealing device, 51-O-ring, 52-Sealing shell, 53-Rectangular elastic sealing ring, 54-Bolt, 55-Nut, 6-Hydraulic steering device, 61-Hydraulic jack, 611-Hydraulic fork, 612-Piston rod, 613-Front cover, 614-Piston, 615-Hydraulic cylinder head, 616-Hydraulic cylinder, 617-Rear cover, 62-First hinge fixing base, 7-Motor worm gear auxiliary steering device, 71-Motor worm gear jack, 711-Motor fork, 712-Motor, 713-Worm, 714-Worm gear, 715-Plunger, 716-Motor end cover, 717-Bearing seat, 718-Plunger sleeve, 719-Plunger end cover, 72-Second hinge fixing base, 81-Control unit. Detailed Implementation

[0020] The following is in conjunction with the appendix Figure 1 To be continued Figure 5 The present invention will be further illustrated by describing a preferred embodiment in detail.

[0021] It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationship, or adjustments to the size should still fall within the scope of the technical content disclosed in the present invention, provided that they do not affect the effects and objectives that the present invention can produce.

[0022] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the expressly listed elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0023] like Figure 1 As shown, the present invention provides a pipe jacking machine head that is flexible in steering, reliable in sealing, and suitable for long-distance jacking, comprising: The cutterhead 1 is located at the foremost end of the pipe jacking machine head and is used to cut the soil in the jacking path; The front shield 2 is a cylindrical pressure-bearing structure, located on the rear side of the cutter head 1. Its front end is connected to the cutter head 1 through the main shaft, providing installation support and drive bearing for the cutter head 1. The middle shield 3 is a cylindrical pressure-bearing structure, coaxially arranged on the rear side of the front shield 2. A first turning clearance is reserved between its front end and the front shield 2 to accommodate the deflection action of the front shield 2 relative to the middle shield 3 during the turning of the pipe jacking machine head. The rear shield 4 is a cylindrical pressure-bearing structure, coaxially arranged on the rear side of the middle shield 3. A second turning clearance is reserved between its front end and the middle shield 3 to accommodate the deflection action of the middle shield 3 relative to the rear shield 4 during the turning of the pipe jacking machine head. The quick-release sealing device 5 is provided in two sets, which are respectively installed at the first turning gap between the front shield 2 and the middle shield 3 and at the second turning gap between the middle shield 3 and the rear shield 4, so as to realize dynamic sealing between adjacent shields. Multiple hydraulic steering devices 6 are uniformly hinged in the first steering gap between the front shield 2 and the middle shield 3 in the circumferential direction, connecting the front shield 2 and the middle shield 3, and driving the pipe jacking machine head to achieve a large-angle main steering action while jacking; Multiple motor worm gear auxiliary steering devices 7 are evenly hinged in the second steering gap between the middle shield 3 and the rear shield 4 in the circumferential direction to connect the middle shield 3 and the rear shield 4. They work with the hydraulic steering device 6 to achieve auxiliary steering action of the jacking machine head during jacking, that is, precise fine adjustment of the steering angle. Moreover, the motor worm gear auxiliary steering device 7 has a reverse self-locking function to stabilize the posture of the head during long-distance jacking. The control device (not shown in the figure) is connected to the hydraulic steering device 6 and the motor worm gear auxiliary steering device 7 respectively, so as to realize the jacking and steering control of the jacking machine head.

[0024] The rear end of the rear shield 4 is connected to the external jacking cylinder to transmit the thrust of the external jacking cylinder to the entire head of the pipe jacking machine.

[0025] Furthermore, such as Figure 2 and Figure 3 As shown, annular grooves are respectively formed on the outer circumferential surfaces of the rear end of the front shield 2, the front and rear ends of the middle shield 3, and the front end of the rear shield 4. Each set of quick-release sealing devices 5 includes: O-rings 51 are installed in the annular grooves on the outer circumference of the front shield 2, the front and rear ends of the middle shield 3, and the front end of the rear shield 4, respectively. The sealing shell 52 is a split annular wrapping structure with upper and lower parts that are closed at the top and bottom. It includes an upper half and a lower half of a semi-circular ring shape. The inner surface of the sealing shell 52 is provided with an annular sealing groove corresponding to the position of the O-ring elastic sealing ring 51. Thus, when installed, the sealing shell 52 can wrap around the outside of the first / second turning gap of the adjacent shield body, so that the annular groove on the outer circumference of the shield body and the annular sealing groove on the inner surface of the sealing shell 52 form a complete annular receiving cavity, and limit the O-ring elastic sealing ring 51 to be accommodated in the annular receiving cavity. The thickness of the O-ring elastic sealing ring 51 is greater than the total radial height of the annular receiving cavity, so as to generate a pre-tight sealing force when the O-ring elastic sealing ring 51 is compressed, thereby achieving interference fit and forming a radial seal. A rectangular elastic sealing ring 53 is installed at the mating surfaces of the upper and lower halves of the sealing shell 52 to achieve interface sealing. Specifically, corresponding rectangular sealing grooves are provided on the mating surfaces of the upper and lower halves of the sealing shell 52. Thus, during installation, the rectangular sealing grooves of the upper and lower halves form a complete rectangular receiving cavity, and the rectangular elastic sealing ring 53 is contained within this rectangular receiving cavity. The thickness of the rectangular elastic sealing ring 53 is greater than the total groove depth of the rectangular receiving cavity, so as to generate a pre-tight sealing force when the rectangular elastic sealing ring 53 is compressed, thereby achieving interference fit and forming an axial seal. The connectors, including multiple sets of bolts 54 and nuts 55, are arranged at equal intervals along the mating surface of the sealing shell 52 to lock the sealing shell 52, thereby enabling the installation and disassembly of the upper and lower halves of the sealing shell 52. In a preferred embodiment of the invention, the number of connectors is sufficient to ensure that the locking force is evenly distributed along the mating surface, ensuring the consistency of the compression of the sealing ring and the reliability of the seal, thereby effectively extending the service life of the pipe jacking machine head.

[0026] It is understood that, in the preferred embodiment of the present invention, the sealing shell 52 is made of high-hardness alloy steel in the connection part that contacts the end faces of the front shield 2, the middle shield 3, and the rear shield 4 (i.e., the part on the inner surface of the sealing shell 52 with an annular sealing groove), while the rest of the main body is made of high-strength fiber-reinforced rubber. It can adapt to the rotation of the shield body and undergo elastic deformation, always maintaining a tight fit with the outer wall of the shield body. The O-ring elastic sealing ring 51 and the rectangular elastic sealing ring 53 are both made of hydrogenated nitrile rubber, which has excellent wear resistance, oil resistance and tear resistance, and is suitable for long-term construction needs in underground water and soil environments.

[0027] Understandably, in practical applications, when the upper and lower halves of the sealing shell 52 are connected and locked by bolts 54 and nuts 55, the inner surface of the sealing shell 52 will uniformly compress the O-ring elastic seal 51, causing it to elastically deform and completely fill the assembly gap between the sealing shell 52 and the outer wall of the shield, forming the first reliable radial main seal. At the same time, the locked sealing shell 52 will synchronously compress the rectangular elastic seal 53, causing it to completely fill the gap at the joint between the upper and lower halves of the sealing shell 52, forming the second axial auxiliary seal. Thus, the two seals together constitute a double sealing barrier, ensuring the absolute sealing reliability of the connection interface between the shields during jacking and turning.

[0028] Furthermore, such as Figure 4 As shown, in this preferred embodiment, a total of four hydraulic steering devices 6 are used, and each hydraulic steering device 6 includes: a hydraulic jack 61 and a pair of first hinge fixing bases 62. Since four hydraulic steering devices 6 are used, the four pairs of first hinge fixing bases 62 are uniformly and symmetrically fixedly installed circumferentially on the rear end face of the front shield 2 and the front end face of the middle shield 3, corresponding to the upper, lower, left, and right positions of the machine head, respectively. The center line connecting each pair of first hinge fixing bases 62 is parallel to the main shaft axis of the machine head to ensure stable axial transmission of steering force. Both ends of each hydraulic jack 61 are hinged to the corresponding pair of first hinge fixing bases 62 via hydraulic fork-shaped parts 611 to accommodate the angular swing of the hydraulic jack 61 during steering.

[0029] Furthermore, the hydraulic jack 61 is a double-acting single-piston rod hydraulic cylinder, comprising: a front hydraulic fork-shaped component 611, a piston rod 612, a front cover 613, a piston 614, a hydraulic cylinder cover 615, a hydraulic cylinder 616, a rear cover 617, and a rear hydraulic fork-shaped component 611. The hydraulic cylinder 616 is the pressure-bearing body of the jack, coaxial with the central axes of the piston rod 612, piston 614, front cover 613, and rear cover 617. The front cover 613 and rear cover 617 are respectively sealed and installed at the front and rear ends of the hydraulic cylinder 616, forming a sealed hydraulic chamber together with the hydraulic cylinder 616. The hydraulic cylinder cover 615 is installed between the mating end faces of the front cover 613 and the hydraulic cylinder 616, used to assist in enhancing the sealing performance and assembly positioning accuracy of the front end of the hydraulic cylinder. The piston 614... Fixed to the rear end of the piston rod 612, a sliding seal is installed in the inner cavity of the hydraulic cylinder 616, thereby dividing the hydraulic chamber into a piston rod chamber and a piston rod-less chamber; the front end of the piston rod 612 protrudes from the front cover 613 and is fixedly connected to the front hydraulic fork-shaped component 611, for hinged to the first hinge fixing base 62 located on the rear end face of the front shield 2; the rear end of the rear cover 617 is fixed with the rear hydraulic fork-shaped component 611, for hinged to the first hinge fixing base 62 located on the front end face of the middle shield 3.

[0030] In this embodiment, the hydraulic jack 61 is also equipped with a built-in telescopic displacement sensor, which can collect the telescopic information of the piston rod 612 in real time and transmit it to the control device to realize closed-loop displacement control. The hydraulic jack 61 has the advantages of strong load-bearing capacity, precise control, compact structure and high safety. It can efficiently and accurately control the direction of the pipe jacking machine head, meet the strict requirements for direction adjustment in pipe jacking construction, and the hydraulic cylinder 616 and the matching hydraulic pump of the hydraulic jack 61 are installed in the pipe jacking machine head to adapt to the needs of long-distance jacking operations.

[0031] Furthermore, such as Figure 5As shown, in this preferred embodiment, a total of four motor worm gear auxiliary steering devices 7 are used, and each motor worm gear auxiliary steering device 7 includes: a motor worm gear jack 71 and a pair of second hinge fixing bases 72. Since four motor worm gear auxiliary steering devices 7 are used, the installation method of the four pairs of second hinge fixing bases 72 corresponds to the first hinge fixing base 62. They are uniformly and symmetrically fixedly installed on the rear end face of the middle shield 3 and the front end face of the rear shield 4 along the circumference, respectively corresponding to the upper, lower, left and right positions of the machine head, and corresponding one-to-one with the circumferential position of the first hinge fixing base 62. This ensures that the positions of the motor worm gear jack 71 and the hydraulic jack 61 correspond to each other, so as to ensure the coaxial transmission of steering force. Both ends of each motor worm gear jack 71 are hinged to the corresponding pair of second hinge fixing bases 72 through motor fork-shaped parts 711 to adapt to the angular swing of the motor worm gear jack 71 during the steering process.

[0032] Furthermore, the motor worm gear jack 71 is an electrically servo-driven self-locking linear actuator, comprising: a front motor fork 711, a motor 712, a worm 713, a worm wheel 714, a plunger 715, a motor end cover 716, a bearing seat 717, a plunger sleeve 718, a plunger end cover 719, and a rear motor fork 711. The plunger sleeve 718 serves as the mounting body of the motor worm gear jack 71, and is horizontally coaxially arranged. The motor 712 is fixedly mounted on the front end of the plunger sleeve 718 via the motor end cover 716, providing driving power to the device. The worm 713 is rotatably mounted in the inner cavity of the plunger sleeve 718 via the bearing seat 717, and its front end is coaxially connected to the output shaft of the motor 712. The worm wheel 714 is rotatably mounted in the inner cavity of the plunger sleeve 718, meshing with the worm 713 for transmission. The plunger 715 is disposed in the inner cavity of the plunger sleeve 718, and its front end engages with the internal thread in the worm gear 714; the motor end cover 716 and the plunger end cover 719 are respectively sealed and installed on the front end of the motor 712 and the rear end of the plunger sleeve 718; the front motor fork-shaped member 711 is fixed to the front end of the motor end cover 716 for hinge connection with the front hinge fixing base; the rear motor fork-shaped member 711 is fixed to the rear end of the plunger end cover 719 for hinge connection with the rear hinge fixing base.

[0033] Furthermore, the control device (not shown in the figure) includes: Multiple control units 81 are respectively installed on the first hinge fixing base 62 and the second hinge fixing base 72, and are configured one-to-one with each of the hydraulic jacks 61 and the motor worm gear jacks 71, for real-time and accurate transmission of the extension and retraction information of the hydraulic jacks 61 and the motor worm gear jacks 71; it can be understood that in the preferred embodiment of the present invention, a total of 8 control units 81 are required, respectively installed on four pairs of the first hinge fixing bases 62 and four pairs of the second hinge fixing bases 72; A controller (not shown in the figure) is installed inside the rear shield 4 and is communicatively connected to each of the corresponding control units 81. It coordinates and controls the hydraulic steering device 6 and the motor-driven worm gear auxiliary steering device 7 based on the actual posture and extension / retraction information of the pipe jacking machine head. In a preferred embodiment of the invention, eight control units 81 are provided, requiring only one controller to control all eight.

[0034] Specifically, in practical applications, it can be understood that the hydraulic steering device 6 and the motor worm gear auxiliary steering device 7 work together to form a two-stage steering system for the jacking machine head. It is worth noting that after the hydraulic steering device 6 completes a large-angle coarse adjustment, the control device controls the extension and retraction of the corresponding motor worm gear jack 71, driving the middle shield 3 to produce a corresponding fine-tuning deflection relative to the rear shield 4, correcting residual positional deviations until the jacking machine head position is completely matched to the designed jacking axis. Simultaneously, because the motor worm gear jack 71 has a reverse self-locking characteristic, when the motor 712 stops driving, the external axial load will not be able to drive the worm wheel 714 and worm 713 to rotate in the opposite direction, automatically locking the position of the plunger 715. This effectively prevents the jacking machine head from shifting due to uneven external soil pressure. Even in emergency situations such as power outages or hydraulic system failures, the jacking machine head position can be stably locked, ensuring construction safety during long-distance jacking.

[0035] It should be noted that, during the operation of this invention, the hydraulic jack 61 of the hydraulic steering device 6 includes both single-cylinder basic operation and multi-cylinder coordinated steering operation, as detailed below: For the basic operation of the single cylinder of the hydraulic jack 61: the hydraulic pump operates, drawing in and pressurizing the hydraulic oil in the tank into high-pressure hydraulic oil; the high-pressure hydraulic oil is transported through the oil circuit to the piston rodless chamber of the hydraulic cylinder 616. Based on Pascal's law, the pressure of the high-pressure hydraulic oil is transmitted in the sealed chamber, causing the piston 614 to be subjected to an axial forward thrust; the piston 614 drives the piston rod 612 to extend axially forward under the action of this thrust, and then through the hydraulic fork-shaped part 611 on the front side and the first hinge fixed base 62, drives the front bearing component fixedly connected to it to move synchronously, and the front bearing component here is specifically the front shield 2 and the cutter head 1 installed on the front shield 2; during reset, the oil circuit is switched by the control valve group, so that the high-pressure hydraulic oil enters the piston rod chamber of the hydraulic cylinder 616, while the hydraulic oil in the piston rodless chamber flows back to the oil tank through the return oil path, and the piston 614 drives the piston rod 612 to retract axially under the action of the pressure difference, completing the single cylinder reset.

[0036] Regarding the multi-cylinder coordinated steering operation of the hydraulic jacks 61: In a preferred embodiment of the present invention, the steering action of the front shield 2 of the pipe jacking machine head is achieved through the coordinated differentiated control of four sets of hydraulic jacks 61 evenly arranged in the circumference. The four sets of hydraulic jacks 61 correspond to the upper, lower, left, and right directions of the pipe jacking machine head, respectively. The control device calculates and controls the target extension and output thrust of each hydraulic jack 61 based on the preset design jacking route and the real-time attitude data of the pipe jacking machine head, combined with the real-time extension and retraction information fed back by the extension and retraction displacement sensors built into each hydraulic jack 61. This causes the hydraulic jacks 61 in different directions to form differentiated extension / retraction actions, thereby generating a deflection torque in the corresponding direction between the front shield 2 and the middle shield 3, driving the front shield 2 to deflect relative to the middle shield 3 in a preset direction, and finally completing the large-angle steering and correction action of the pipe jacking machine head.

[0037] Furthermore, it should be noted that during the operation of this invention, the motor worm gear jack 71 of the motor worm gear auxiliary steering device 7 also includes single-cylinder basic operation and multi-cylinder coordinated steering fine-tuning operation, as detailed below: For the single-cylinder basic operation of the motor worm gear jack 71: the motor 712 drives the worm 713 to rotate, and the worm 713 drives the worm wheel 714 meshing with it to rotate, converting the axial rotational motion of the motor output shaft into the radial rotational motion of the worm wheel, while utilizing the reduction characteristics of the worm gear transmission to amplify the torque; the rear end of the plunger 715 is fixedly connected to the rear motor fork-shaped part 711 through the plunger end cap 719. In this state, the plunger 715 is limited and cannot move axially. The worm wheel 714 moves back and forth along the axial direction of the plunger 715 through threaded engagement, and drives the worm wheel 714 to rotate through the front motor fork-shaped part 711 and the second hinge fixed base 72. Its fixedly connected front-end load-bearing components operate synchronously, and the front-end load-bearing components here are specifically the middle shield 3 and the front shield 2 and cutter head 1 installed on the middle shield 3; during reset, the motor 712 reverses to drive the worm 713 and worm wheel 714 to rotate in the opposite direction, causing the worm wheel 714 to move backward along the axial direction of the plunger 715, driving the plunger sleeve 718, the motor 712 and the front motor fork 711 to retract axially and complete the single-cylinder reset; at the same time, based on the reverse self-locking characteristic of the worm gear transmission, when the motor 712 stops driving, the external axial load cannot drive the worm wheel 714 and worm 713 to rotate in the opposite direction, and can automatically lock the current telescopic position.

[0038] For the multi-cylinder coordinated steering fine-tuning operation of the motor worm gear jack 71: In a preferred embodiment of the present invention, the steering fine-tuning action of the shield 3 in the jacking machine head is achieved through the coordinated differentiated control of four sets of motor worm gear jacks 71 evenly arranged in the circumference. The four sets of motor worm gear jacks 71 correspond to the upper, lower, left, and right positions of the jacking machine head, and correspond one-to-one with the circumferential position of the hydraulic jack 61; the control device is based on the preset design jacking route and the jacking machine... The real-time attitude data of the head, combined with the real-time extension and retraction information fed back by each motor worm gear jack 71, calculates and controls the target extension and retraction amount and output thrust of each directional motor worm gear jack 71, so that the motor worm gear jack 71 in different directions forms differentiated extension / retraction actions, thereby generating a corresponding fine-tuning deflection torque between the middle shield 3 and the rear shield 4, driving the middle shield 3 to deflect relative to the rear shield 4 in a preset direction, and finally completing the fine-tuning and correction action of the turning angle of the pipe jacking machine head.

[0039] Furthermore, in a preferred embodiment of the present invention, in order to adapt to long-distance continuous jacking operations, the present invention has integrated and optimized the supporting system of the machine head for the needs of long-distance continuous operations. The front cavity of the front shield 2 houses the main drive motor and reducer of the drive cutterhead 1, while the rear cavity of the middle shield 3 integrates a lubricating oil pump and a cooling water tank. The lubricating oil circuit extends from the lubricating oil pump to the main drive motor, reducer, hinge pins, and jack moving parts, providing continuous forced lubrication for all moving components. The inlet and outlet of the cooling water tank are connected to cooling pipes to form a complete closed-loop cooling circuit. These cooling pipes are arranged around the outside of each heat-generating component to achieve closed-loop temperature control, ensuring that the operating temperature of each component remains within a reasonable range and preventing overheating damage caused by long-distance continuous operation. The hydraulic jack 61 and the motor worm gear jack 71 are powered by a box-type transformer outside the pipe jacking machine head, connected to a distribution cabinet. The low-voltage side of the box-type transformer then supplies power to the various electrical devices on the pipe jacking machine head, ensuring continuous and stable operation of the equipment during long-distance jacking.

[0040] Furthermore, in another embodiment of the present invention, such as Figure 6 and Figure 7 As shown, the upper and lower halves of the sealing shell 52 are respectively provided with outwardly protruding connecting lugs at their circumferential parting ends. The connecting lugs are located within the outer circumferential operable area of ​​the sealing shell 52 after assembly. The connector includes multiple sets of bolts 54 and nuts 55. The bolts 54 pass through the corresponding connecting lugs and cooperate with the nuts 55 to lock the upper and lower halves of the sealing shell 52 from the outer circumference. Thus, when maintenance or replacement of the sealing structure is required, the operator can remove the bolts 54 and nuts 55 from the outer circumference of the sealing shell 52 without disassembling the front shield 2, middle shield 3, and rear shield 4, and remove the upper and lower halves of the sealing shell 52 radially outward, effectively reducing the maintenance difficulty of the pipe jacking machine head during long-distance jacking and shortening the downtime for maintenance.

[0041] In summary, this invention provides a pipe jacking machine head that is flexible in steering, reliable in sealing, and suitable for long-distance jacking. It adopts a split-type quick-release double sealing structure, which ensures flexible steering at large angles between the shield bodies while achieving dynamic and reliable sealing across the entire steering angle range, and significantly reduces the difficulty of downhole maintenance. At the same time, it also adopts a two-stage coordinated steering system with hydraulic main steering and motor worm gear assisted steering, which has the functions of rapid correction at large angles, micron-level precise fine adjustment, and reverse self-locking attitude maintenance. The steering control is flexible and highly accurate, and has significant practical value.

[0042] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A pipe jacking machine head, characterized in that, include: The cutterhead is located at the foremost end of the pipe jacking machine head; The front shield is a cylindrical pressure-bearing structure located on the rear side of the cutter head, with its front end connected to the cutter head; The middle shield is a cylindrical pressure-bearing structure, coaxially arranged on the rear side of the front shield, with a first turning clearance reserved between its front end and the front shield; The rear shield is a cylindrical pressure-bearing structure, coaxially arranged on the rear side of the middle shield, with a second turning clearance reserved between its front end and the middle shield; The quick-release sealing device is provided in two sets, which are respectively installed at the first turning gap and the second turning gap to achieve dynamic sealing between adjacent shield bodies; Multiple hydraulic steering devices are evenly hinged in the first steering gap along the circumference to connect the front shield and the middle shield, and drive the jacking machine head to achieve the main steering action while jacking; Multiple motor worm gear auxiliary steering devices are evenly hinged in the second steering clearance along the circumference to connect the middle shield and the rear shield, and work with the hydraulic steering device to achieve fine adjustment of the steering angle while pushing forward; The control device is connected to the hydraulic steering device and the motor worm gear auxiliary steering device respectively, so as to realize the jacking and steering control of the jacking machine head; Among them, annular grooves are respectively provided on the outer circumferential surface of the rear end of the front shield, the front and rear ends of the middle shield, and the front end of the rear shield. Each set of the quick-release sealing devices includes; O-rings are installed in the respective annular grooves. The sealing shell is a split annular enclosed structure with upper and lower halves that are closed at the top and bottom. It includes an upper half and a lower half of a semi-circular ring shape, and the inner surface of the sealing shell is provided with an annular sealing groove corresponding to the position of the O-ring elastic sealing ring. The sealing shell is wrapped around the outside of the first or second turning gap of the adjacent shield body, so that the annular groove of the shield body and the annular sealing groove of the sealing shell form an annular receiving cavity. The O-ring elastic sealing ring is contained and accommodated in the annular receiving cavity. The thickness of the O-ring elastic sealing ring is greater than the total radial height of the annular receiving cavity to form a radial seal. A rectangular elastic sealing ring is installed at the mating surfaces of the upper and lower halves of the sealing shell; wherein, corresponding rectangular sealing grooves are formed on the mating surfaces of the upper and lower halves of the sealing shell; the rectangular sealing grooves of the upper half and the lower half form a rectangular receiving cavity, and the rectangular elastic sealing ring is contained within the rectangular receiving cavity; and the thickness of the rectangular elastic sealing ring is greater than the total groove depth of the rectangular receiving cavity to form an axial seal; Connectors are arranged at equal intervals along the mating surface of the sealing shell to lock the upper and lower halves of the sealing shell.

2. The pipe jacking machine head as described in claim 1, characterized in that, The connector includes multiple sets of bolts and nuts; The part of the sealing shell that contacts the end face of the shield body is made of high-hardness alloy steel, and the rest is made of high-strength fiber-reinforced rubber. Both the O-ring and the rectangular elastic sealing ring are made of hydrogenated nitrile rubber.

3. The pipe jacking machine head as described in claim 1, characterized in that, A total of four hydraulic steering devices are provided. Each hydraulic steering device includes a hydraulic jack and a pair of first hinge fixing bases. The four pairs of first hinge fixing bases are evenly and symmetrically fixedly installed on the rear end face of the front shield and the front end face of the middle shield along the circumference, respectively corresponding to the upper, lower, left and right positions of the machine head. The two ends of the hydraulic jack are respectively hinged to the corresponding pair of first hinge fixing bases to adapt to the angular swing of the hydraulic jack during the steering process.

4. The pipe jacking machine head as described in claim 3, characterized in that, The hydraulic jack includes: a front hydraulic fork-shaped component, a piston rod, a front cover, a piston, a hydraulic cylinder cover, a hydraulic cylinder, a rear cover, and a rear hydraulic fork-shaped component. The hydraulic cylinder is the pressure-bearing body of the hydraulic jack, and is coaxial with the central axis of the piston rod, piston, front cover, and rear cover. The front cover and rear cover are respectively sealed and installed at the front and rear ends of the hydraulic cylinder, forming a hydraulic chamber together with the hydraulic cylinder. The hydraulic cylinder cover is installed between the mating end faces of the front cover and the hydraulic cylinder to help enhance the sealing performance and assembly positioning accuracy of the front end of the hydraulic cylinder. The piston is fixed to the rear end of the piston rod and is slidably and sealed in the inner cavity of the hydraulic cylinder, dividing the hydraulic chamber into a piston rod chamber and a piston rod-free chamber. The front end of the piston rod protrudes from the front cover and is fixedly connected to the front hydraulic fork-shaped component. The rear end of the rear cover is fixed with the rear hydraulic fork-shaped component, and the two hydraulic fork-shaped components are respectively hinged to the corresponding first hinge fixing base.

5. The pipe jacking machine head as described in claim 4, characterized in that, The hydraulic jack has a built-in telescopic displacement sensor, which is communicatively connected to the control device to collect real-time information on the extension and retraction of the piston rod, thereby achieving closed-loop displacement control.

6. The pipe jacking machine head as described in claim 3, characterized in that, Four motor worm gear auxiliary steering devices are provided. Each motor worm gear auxiliary steering device includes a motor worm gear jack and a pair of second hinge fixing bases. The four pairs of second hinge fixing bases are evenly and symmetrically fixedly installed on the rear end face of the middle shield and the front end face of the rear shield along the circumference, respectively corresponding to the upper, lower, left and right positions of the machine head, and corresponding one-to-one with the circumferential position of the first hinge fixing base. The two ends of the motor worm gear jack are respectively hinged to the corresponding pair of second hinge fixing bases to adapt to the angular swing of the motor worm gear jack during the steering process.

7. The pipe jacking machine head as described in claim 6, characterized in that, The motor worm gear jack includes: a front motor fork-shaped component, a motor, a worm, a worm wheel, a plunger, a motor end cover, a bearing seat, a plunger sleeve, a plunger end cover, and a rear motor fork-shaped component. The motor is fixedly mounted to the front end of the plunger sleeve via a motor end cover. The worm gear is rotatably mounted in the inner cavity of the plunger sleeve via a bearing seat, and the front end of the worm gear is coaxially connected to the output shaft of the motor. The worm wheel is rotatably mounted in the inner cavity of the plunger sleeve and meshes with the worm gear for transmission. The plunger is disposed in the inner cavity of the plunger sleeve, and its front end is engaged with the internal thread of the worm wheel. The motor end cover and the plunger end cover are respectively sealed and mounted to the front end of the motor and the rear end of the plunger sleeve. The front motor fork is fixed to the front end of the motor end cover, and the rear motor fork is fixed to the rear end of the plunger end cover. The two motor forks are respectively hinged to the corresponding second hinge fixing base.

8. The pipe jacking machine head as described in claim 6, characterized in that, The control device includes: Multiple control units are installed on the first hinge fixing base and the second hinge fixing base respectively, and are set up one by one with each hydraulic jack and motor worm gear jack, for real-time transmission of extension and retraction information; The controller, installed inside the rear shield, is communicatively connected to each control unit, hydraulic steering device, and motor worm gear auxiliary steering device. It is used to coordinate and control the hydraulic steering device and motor worm gear auxiliary steering device based on the actual posture and extension / retraction information of the pipe jacking machine head.

9. The pipe jacking machine head as described in claim 1, characterized in that, The front cavity of the front shield is equipped with the main drive motor and reducer for driving the cutter disc. The rear cavity of the central shield integrates a lubricating oil pump and a cooling water tank. The lubricating oil circuit extends from the lubricating oil pump to each moving part to provide continuous forced lubrication. The inlet and outlet of the cooling water tank are connected to cooling pipes to form a complete closed-loop cooling circuit. The cooling pipes are arranged around the outside of each heat-generating part to achieve closed-loop temperature control. Each electrical device at the jacking machine head is powered by an external box-type transformer via a distribution cabinet.

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