Slurry pipeline compensation device

Abstract

The utility model provides a slurry pipeline compensation device which is communicated with a slurry pipeline in a shield tunneling machine, the slurry pipeline compensation device comprises a flexible pipe section and a telescopic pipe section which are connected, and the telescopic pipe section is provided with a first rigid pipe and a second rigid pipe which are connected together in a sleeved mode. And a compensation mechanism for driving the first rigid pipe and the second rigid pipe to be close to each other or separated from each other is connected between the first rigid pipe and the second rigid pipe. According to the utility model, the expansion compensation amount of the slurry pipeline can be improved, so that the slurry pipeline is prevented from being damaged in a small-bending-radius turning process or a hinging oil cylinder expansion process.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel boring machines, in particular to a mud pipeline compensation device. Background Art

[0002] As rail transit is gradually promoted in more and more cities, shield machines are increasingly used in subways or road and railway tunnels. Slurry shield machines are increasingly widely used in the tunnel industry because of their precise settlement control and wide adaptability to strata. However, as the application conditions become more and more complex, the turning radius that shield machines need to adapt to becomes smaller and smaller. At the same time, in order to meet the conditions of tool change space and shield posture adjustment, active articulated shield machines came into being, which has a trend of gradually replacing passive articulation and becoming the mainstream form.

[0003] Active articulated slurry shield machines, during small radius turning or articulated cylinder extension and retraction, the flexibility and extension of the steel pipe are almost zero. Therefore, under the above working conditions, it is very likely that the equipment will be irreversibly damaged due to excessive front and rear tension. In order to solve the above problems, flexible joints are used in the prior art to compensate for bending and extension, but the extension and retraction of the general articulated cylinder can reach 300mm to 400mm, and the general length of the flexible joint cannot compensate for the large deformation of the length; if a longer flexible joint is customized, the cost will be very high, and the excessive length will cause serious risks of easy wear and explosion of the pipe. Utility Model Content

[0004] The utility model aims to provide a mud pipeline compensation device, which improves the expansion and contraction compensation amount of the mud pipeline, thereby preventing the mud pipeline from being damaged during a small bending radius turning process or an articulated oil cylinder expansion and contraction process.

[0005] The utility model provides a mud pipeline compensation device, which is connected to the mud pipeline in a shield machine. The mud pipeline compensation device comprises a connected flexible pipe section and a telescopic pipe section. The telescopic pipe section has a first rigid pipe and a second rigid pipe that are sleeved together. A compensation mechanism is connected between the first rigid pipe and the second rigid pipe to drive the two to approach or separate from each other.

[0006] In a preferred embodiment of the present utility model, the compensation mechanism has a plurality of compensation cylinders, and the plurality of compensation cylinders are arranged at intervals on the circumferential outer side of the mud pipeline compensation device.

[0007] In a preferred embodiment of the present utility model, the compensation oil cylinder is connected to an oil circuit unit for driving the piston rod of the compensation oil cylinder to extend or retract.

[0008] In a preferred embodiment of the present invention, the oil circuit unit has an oil supply pipeline and an oil return pipeline, the chamber of the compensating cylinder is divided into a rod chamber and a rodless chamber by the piston rod, and the rod chamber and the rodless chamber are switched and connected to the oil supply pipeline and the oil return pipeline respectively through a reversing valve.

[0009] In a preferred embodiment of the present utility model, the reversing valve has a first working position capable of pushing the piston rod to extend, and a second working position capable of pushing the piston rod to retract;

[0010] Wherein, when the articulated oil cylinder in the shield machine extends and causes the mud pipeline to be extended, the reversing valve switches to the first working position; when the articulated oil cylinder retracts and causes the mud pipeline to be shortened, the reversing valve switches to the second working position.

[0011] In a preferred embodiment of the present invention, the reversing valve also has a third working position capable of keeping the piston rod in a fixed position; when the articulated cylinder stops moving and the extension length of the piston rod of the compensation cylinder is the same as the extension length of the articulated cylinder, the reversing valve switches to the third working position.

[0012] In a preferred embodiment of the present utility model, the reversing valve has an oil inlet, an oil return port, a first oil port and a second oil port, a first pipeline is connected between the rodless chamber and the first oil port, and a second pipeline is connected between the rod chamber and the second oil port.

[0013] In a preferred embodiment of the present invention, both the first pipeline and the second pipeline are provided with throttle valves, and the first pipeline is provided with a pressure sensor.

[0014] In a preferred embodiment of the present utility model, a stroke sensor for sensing the displacement of the piston rod is provided on the compensation cylinder.

[0015] In a preferred embodiment of the present utility model, a pressure reducing valve is connected between the oil supply pipeline and the oil return pipeline.

[0016] Compared with the prior art, the technical solution described in the utility model has the following characteristics and advantages:

[0017] The mud pipe compensation device described in the utility model is used to compensate for the bending and expansion and contraction of the mud pipe through the flexible pipe section and the telescopic pipe section respectively, and the displacement of the compensation cylinder and the articulated cylinder is kept consistent at any time, and the passive compensation is changed to active compensation, while the free expansion and contraction function is not affected, thereby avoiding the problem of severe deformation of the flexible pipe section (expansion joint hose) due to passive expansion and contraction, and can more effectively prevent irreversible damage such as pipeline pulling off or pipe bursting caused by relative displacement; therefore, the mud pipe compensation device solves the problem of severe deformation of the expansion joint hose in the actively articulated mud pipe, and even pulling off and bursting of the pipe, thereby improving the construction efficiency and ensuring efficient and safe excavation of the shield. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0019] The drawings described herein are only for explanation purposes and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only for illustration purposes to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. Under the guidance of the present invention, those skilled in the art can select various possible shapes and proportional dimensions to implement the present invention according to specific circumstances.

[0020] Figure 1 This is a schematic diagram of the structure of the mud pipeline compensation device of the utility model;

[0021] Figure 2 This is a schematic diagram of the distribution of mud pipes in the shield machine of the utility model;

[0022] Figure 3 It is a schematic diagram of the connection structure of the oil circuit unit of the utility model.

[0023] Description of Figure Numbers:

[0024] 10. Mud pipeline compensation device; 11. Flexible pipe section; 12. Telescopic pipe section;

[0025] 20 first rigid tube; 21, second rigid tube; 23, compensation cylinder; 231, rod chamber; 232, rodless chamber; 233, piston rod;

[0026] 30. Oil circuit unit; 31. Oil supply pipeline; 32. Oil return pipeline; 33. First pipeline; 34. Second pipeline;

[0027] 40. reversing valve; 41. first working position; 42. second working position; 43. third working position;

[0028] 50. Throttle valve; 51. Pressure sensor; 52. Travel sensor; 53. Pressure reducing valve;

[0029] 60. Cutterhead; 61. Main drive; 62. Front of shield; 63. Back of shield; 64. Articulated oil cylinder; 65. Mud inlet pipeline; 66. Mud discharge pipeline;

[0030] P, oil inlet; T, oil return port; A, first oil port; B, second oil port. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0034] like Figure 1 and Figure 2 As shown, the utility model provides a mud pipe compensation device 10, which is connected to the mud pipeline in the shield machine. The mud pipe compensation device 10 includes a connected flexible pipe section 11 and a telescopic pipe section 12. The telescopic pipe section 12 has a first rigid pipe 20 and a second rigid pipe 21 that are sleeved together. A compensation mechanism is connected between the first rigid pipe 20 and the second rigid pipe 21 to drive the two to approach or separate from each other.

[0035] The mud pipe compensation device 10 described in the utility model is used to compensate for the bending and expansion and contraction of the mud pipe through the flexible pipe section 11 and the telescopic pipe section 12 respectively, and the displacement of the compensation cylinder 23 is kept consistent with the displacement of the articulated cylinder 64 at any time, changing from passive compensation to active compensation, while not affecting its free expansion and contraction function, thereby avoiding the problem of severe deformation of the flexible pipe section 11 (expansion joint hose) due to passive expansion and contraction, and can also effectively prevent irreversible damage such as pipeline pulling off or pipe bursting caused by relative displacement; therefore, the mud pipe compensation device 10 solves the problem of severe deformation of the expansion joint hose in the actively articulated mud pipe, and even pulling off and bursting of the pipe, thereby improving construction efficiency and ensuring efficient and safe excavation of the shield.

[0036] Specifically, Figure 2 As shown, it is a schematic diagram of the distribution of mud pipes in the shield machine. A cutterhead 60 is provided at the front end of the shield machine. The cutterhead 60 is connected to the main drive 61, which cuts and crushes the face by means of rotation, extrusion, etc. The main drive 61 is arranged inside the front 62 of the shield body, which is connected to the cutterhead 60 to drive the cutterhead 60 to rotate. The front 62 of the shield body is used to support the soil and serve as a connection basis for other system components. The front 62 of the shield body is connected to the rear 63 of the shield body through a hinge system, thereby making the front 62 of the shield body and the rear 63 of the shield body two independent parts, which can have relative displacement between them, thereby reducing the length of the entire shield body and achieving a smaller The articulated system realizes the turning radius of the shield machine through the telescopic effect of the articulated cylinder 64; the mud inlet pipeline 65 and the mud discharge pipeline 66 are arranged inside the front 62 and the rear 63 of the shield body, the mud inlet pipeline 65 is used to transport fresh slurry to the tunnel face, and the mud discharge pipeline 66 is used to transport the discharge slurry mixed with the excavated debris to the ground outside the tunnel. The mud pipeline compensation device 10 described in the utility model is connected to the mud inlet pipeline 65 or the mud discharge pipeline 66 to compensate for the bending and telescopic effect of the pipeline, so as to avoid damage to the mud inlet pipeline 65 or the mud discharge pipeline 66.

[0037] Furthermore, the mud pipe compensation device 10 described in the utility model has a connected flexible pipe section 11 and a telescopic pipe section 12, wherein the flexible pipe section 11 is mainly used to compensate for the bending deformation of the mud pipe to avoid the mud pipe from cracking or irreversible bending due to excessive bending, and the telescopic pipe section 12 is used to compensate for the telescopic deformation of the mud pipe to avoid the mud pipe from being pulled off or bursting due to excessive stretching or excessive compression.

[0038] like Figure 1As shown, the flexible pipe section 11 is an elastic pipe that can produce recoverable bending deformation. In this embodiment, the flexible pipe section 11 adopts a short section of expansion joint hose, and its two ends are respectively connected to the mud pipeline and the telescopic pipe section 12; the expansion joint hose mainly compensates for the bending displacement of the mud pipeline, and can also compensate for the telescopic displacement of the mud pipeline in a small range. In other embodiments of the utility model, other types of hoses can also be used as the flexible pipe section 11, as long as they can compensate for the bending displacement of the mud pipeline.

[0039] like Figure 1 As shown, the telescopic pipe section 12 is a section of pipe that can automatically extend or contract under the control of a control device, and includes a first rigid pipe 20 and a second rigid pipe 21 that are sleeved together. One end of the first rigid pipe 20 is inserted into the interior of the second rigid pipe 21 and can move axially in the second rigid pipe 21. A sealing structure is provided between the two to seal and prevent the first rigid pipe 20 from leaking mud during the telescopic process. In this embodiment, the first rigid pipe 20 and the second rigid pipe 21 are both a section of steel pipe, the diameter of the second rigid pipe 21 is larger than the diameter of the first rigid pipe 20, the free end of the first rigid pipe 20 is connected to the expansion joint hose, and the other end is connected to the mud pipeline. A compensation mechanism is connected between the first rigid pipe 20 and the second rigid pipe 21 to drive the two to approach or separate from each other. The compensation mechanism can be a common oil cylinder, air cylinder, etc. in the prior art, but is not limited to the above structure, as long as it can drive the telescopic pipe section 12 to produce axial telescopic displacement.

[0040] The structure of the preferred embodiment of the mud pipeline compensation device 10 of the utility model will be further described in detail below:

[0041] According to one embodiment of the present utility model, Figure 1 As shown, the compensation mechanism has a plurality of compensation cylinders 23, and the plurality of compensation cylinders 23 are arranged at intervals on the circumferential outer side of the mud pipeline compensation device 10. The method of driving the telescopic pipe section 12 to extend and retract by the compensation cylinder 23 can utilize the hydraulic system inside the shield machine, avoiding the need to separately set a power source to drive the operation of the compensation mechanism, and the structure is relatively simple; at the same time, the state of the compensation cylinder 23 and the position of the piston rod 233 can be accurately controlled by the reversing valve 40.

[0042] Specifically, Figure 1As shown, one end of the compensation oil cylinder 23 is connected to the flange of the first rigid tube 20 close to the expansion joint hose, and the other end is connected to the flange of the second rigid tube 21 away from the first rigid tube 20. The setting direction of the compensation oil cylinder 23 is parallel to the axial direction of the telescopic tube section 12. In order to ensure the force balance in the circumferential direction of the telescopic tube section 12, so that the first rigid tube 20 can be smoothly extended or retracted, at least two compensation oil cylinders 23 are arranged on the outside of the first rigid tube 20 and the second rigid tube 21, and at least two compensation oil cylinders 23 are evenly arranged on the outside of the telescopic tube section 12 in the circumferential direction.

[0043] According to one embodiment of the present utility model, Figure 1 and Figure 3 As shown, the compensation cylinder 23 is connected to an oil circuit unit 30 for driving a piston rod 233 of the compensation cylinder 23 to extend or retract.

[0044] Specifically, the oil circuit unit 30 has an oil supply pipeline 31 and an oil return pipeline 32. The chamber of the compensation cylinder 23 is divided into a rod chamber 231 and a rodless chamber 232 by a piston rod 233. The rod chamber 231 and the rodless chamber 232 are switched and connected to the oil supply pipeline 31 and the oil return pipeline 32 through a reversing valve 40, respectively.

[0045] In this embodiment, two compensation cylinders 23 are installed on the telescopic pipe section 12, so Figure 3 Two parallel oil circuits are provided on the oil supply line 31 and the oil return line 32, respectively used to control the two compensation oil cylinders 23. Under the control of the reversing valve 40, the rod chamber 231 can be connected to the oil return line 32, and the rodless chamber 232 can be connected to the oil supply line 31. At this time, the piston rod 233 of the compensation oil cylinder 23 is extended under the drive of the hydraulic oil, thereby driving the telescopic pipe section 12 to extend; under the control of the reversing valve 40, the rod chamber 231 can be connected to the oil supply line 31, and the rodless chamber 232 can be connected to the oil return line 32. At this time, the piston rod 233 of the compensation oil cylinder 23 is retracted under the drive of the hydraulic oil, thereby driving the telescopic pipe section 12 to shorten.

[0046] According to one embodiment of the present utility model, Figure 3 As shown, the reversing valve 40 has a first working position 41 capable of pushing the piston rod 233 to extend, and a second working position 42 capable of pushing the piston rod 233 to retract; wherein, when the articulated cylinder 64 in the shield machine extends and causes the mud pipeline to be extended, the reversing valve 40 switches to the first working position 41, and when the articulated cylinder 64 retracts and causes the mud pipeline to be shortened, the reversing valve 40 switches to the second working position 42.

[0047] Specifically, Figure 3As shown, the reversing valve 40 has an oil inlet P, an oil return port T, a first oil port A and a second oil port B. A first pipeline 33 is connected between the rodless chamber 232 and the first oil port A, and a second pipeline 34 is connected between the rod chamber 231 and the second oil port B. The oil inlet P is connected to the oil supply pipeline 31, and the oil return port T is connected to the oil return pipeline 32.

[0048] When the reversing valve 40 is in the first working position 41, inside the reversing valve 40, the oil inlet P is connected to the first oil port A, and the oil return port T is connected to the second oil port B; at this time, the rodless chamber 232 is connected to the oil supply pipeline 31 through the first pipeline 33, and the rod chamber 231 is connected to the oil return pipeline 32 through the second pipeline 34, and the piston rod 233 is extended under the drive of the hydraulic oil, thereby driving the telescopic pipe section 12 to extend.

[0049] When the reversing valve 40 is in the second working position 42, inside the reversing valve 40, the oil inlet P is connected to the second oil port B, and the oil return port T is connected to the first oil port A; at this time, the rodless chamber 232 is connected to the oil return pipeline 32 through the first pipeline 33, and the rod chamber 231 is connected to the oil supply pipeline 31 through the second pipeline 34, and the piston rod 233 retracts under the drive of the hydraulic oil, thereby driving the telescopic pipe section 12 to shorten.

[0050] Further, such as Figure 3 As shown, the reversing valve 40 also has a third working position 43 that can keep the piston rod 233 in a fixed position; when the articulated cylinder 64 stops moving and the extension length of the piston rod 233 of the compensation cylinder 23 is the same as the extension length of the articulated cylinder 64, the reversing valve 40 switches to the third working position 43.

[0051] The reversing valve 40 in this embodiment adopts a three-position four-way reversing valve 40, and the third working position 43 is located between the first working position 41 and the second working position 42, that is, the middle position of the reversing valve 40. In this embodiment, the third working position 43 of the reversing valve 40 adopts a "Y" type connecting structure, that is, the return oil port T is connected to the first oil port A and the second oil port B at the same time, and the oil inlet P is closed.

[0052] When the reversing valve 40 is in the third working position 43, inside the reversing valve 40, the oil inlet P is closed, and the oil return port T is connected to the first oil port A and the second oil port B at the same time; at this time, the rodless chamber 232 is connected to the oil return pipeline 32 through the first pipeline 33, and the rod chamber 231 is also connected to the oil return pipeline 32 through the second pipeline 34, and the piston rod 233 remains stationary under the action of the hydraulic oil.

[0053] According to one embodiment of the present utility model, Figure 3As shown, a throttle valve 50 is provided on both the first pipeline 33 and the second pipeline 34, and a pressure sensor 51 is provided on the first pipeline 33. The throttle valve 50 is used to control the extension or retraction speed of the piston rod 233 in the compensation cylinder 23; the pressure sensor 51 is used to detect the system pressure.

[0054] According to one embodiment of the present utility model, Figure 3 As shown, the compensation oil cylinder 23 is provided with a travel sensor 52 for sensing the displacement of the piston rod 233. The travel sensor 52 is used to detect the displacement X of the piston rod 233. 补 , and the displacement X 补 Feedback to the control system.

[0055] According to one embodiment of the present utility model, Figure 3 As shown, a pressure reducing valve 53 is connected between the oil supply line 31 and the oil return line 32. The pressure reducing valve 53 is used to adjust the pressure difference between the oil supply line 31 and the oil return line 32, thereby controlling the pressure value in the oil circuit unit 30.

[0056] The mud pipeline compensation device described in the utility model is also provided with a PLC control system, which is electrically connected to the articulated oil cylinder 64 and the stroke sensor 52 to receive the displacement X of the articulated oil cylinder 64. 铰 and the displacement X of the compensation cylinder 23 补 At the same time, the PLC control system is electrically connected to the reversing valve 40 to control the reversing valve 40.

[0057] During the specific operation of the shield machine, the operation process of the mud pipeline compensation device described in the utility model is as follows:

[0058] a. When the articulated oil cylinder 64 performs telescopic movement, the shield body front 62 and the shield body rear 63 will have a certain relative displacement (including linear displacement and bending displacement), which will indirectly cause the mud inlet pipeline 65 and mud discharge pipeline 66 in front and behind the shield body to be moved. At this time, the articulated oil cylinder 64 will send its displacement signal (X 铰 ) is transmitted to the PLC control system in real time;

[0059] b. When the PLC control system detects a change in the stroke of the articulated cylinder 64, it will control the oil circuit unit 30 connected to the compensation cylinder 23 to start working, and at the same time give an electrical signal to the reversing valve 40. If the articulated cylinder 64 is in a relatively extended state, the reversing valve 40 is controlled to switch to the first working position 41 to extend the piston rod 233 of the telescopic cylinder; if the articulated cylinder 64 is in a relatively retracted state, the reversing valve 40 is controlled to switch to the second working position 42 to retract the piston rod 233 of the telescopic cylinder.

[0060] c. At this time, the PLC control system will determine the displacement X of the articulated cylinder 64 in real time. 铰and the displacement X of the compensation cylinder 23 补 The size between (the displacement is positive), when X 铰 >X 补 When X is reached, the PLC control system controls the reversing valve 40 to switch to the first working position 41, and the piston rod 233 of the compensation cylinder 23 continues to extend until X 铰 =X 补 At this time, the PLC control system controls the reversing valve 40 to switch to the third working position 43; when X 铰 <X 补 When X is reached, the PLC control system controls the reversing valve 40 to switch to the second working position 42, and the piston rod 233 of the compensation cylinder 23 continues to retract until X 铰 =X 补 At this time, the PLC control system controls the reversing valve 40 to switch to the third working position 43, thereby realizing real-time compensation of the linear displacement of the mud pipeline.

[0061] d. During the adjustment period, if the extension and retraction speed of the piston rod 233 of the compensation cylinder 23 is too fast or too slow, the extension and retraction speed can be adjusted by adjusting the throttle valve 50.

[0062] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only a specific embodiment of the utility model and is not intended to limit the scope of protection of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the scope of protection of the utility model.

Claims

1. A mud pipeline compensation device, characterized in that: The slurry pipeline compensation device (10) is connected to a slurry pipeline in a shield machine, and comprises a connected flexible pipe section (11) and a telescopic pipe section (12). The telescopic pipe section (12) comprises a first rigid pipe (20) and a second rigid pipe (21) which are sleeved together. A compensation mechanism is connected between the first rigid pipe (20) and the second rigid pipe (21) to drive the two to move closer to or away from each other.

2. The mud pipeline compensation device according to claim 1, characterized in that: The compensation mechanism comprises a plurality of compensation cylinders (23), and the plurality of compensation cylinders (23) are arranged at intervals on the circumferential outer side of the mud pipeline compensation device (10).

3. The mud pipeline compensation device according to claim 2 is characterized in that: The compensation oil cylinder (23) is connected to an oil circuit unit (30) for driving a piston rod (233) of the compensation oil cylinder (23) to extend or retract.

4. The mud pipeline compensation device according to claim 3 is characterized in that: The oil circuit unit (30) has an oil supply pipeline (31) and an oil return pipeline (32); the chamber of the compensation oil cylinder (23) is divided into a rod chamber (231) and a rodless chamber (232) by the piston rod (233); the rod chamber (231) and the rodless chamber (232) are respectively switched and connected with the oil supply pipeline (31) and the oil return pipeline (32) through a reversing valve (40).

5. The mud pipeline compensation device according to claim 4, characterized in that: The reversing valve (40) has a first working position (41) capable of pushing the piston rod (233) to extend, and a second working position (42) capable of pushing the piston rod (233) to retract; When the articulated oil cylinder (64) in the shield machine extends and causes the mud pipeline to be extended, the reversing valve (40) switches to the first working position (41); when the articulated oil cylinder (64) retracts and causes the mud pipeline to be shortened, the reversing valve (40) switches to the second working position (42).

6. The mud pipeline compensation device according to claim 5, characterized in that: The reversing valve (40) also has a third working position (43) capable of keeping the position of the piston rod (233) fixed; when the articulated cylinder (64) stops moving and the extension length of the piston rod (233) of the compensation cylinder (23) is the same as the extension length of the articulated cylinder (64), the reversing valve (40) switches to the third working position (43).

7. The mud pipeline compensation device according to claim 6, characterized in that: The reversing valve (40) has an oil inlet (P), an oil return port (T), a first oil port (A) and a second oil port (B); a first pipeline (33) is connected between the rodless chamber (232) and the first oil port (A); and a second pipeline (34) is connected between the rod chamber (231) and the second oil port (B).

8. The mud pipeline compensation device according to claim 7, characterized in that: The first pipeline (33) and the second pipeline (34) are both provided with a throttle valve (50), and the first pipeline (33) is provided with a pressure sensor (51).

9. The mud pipeline compensation device according to claim 6, characterized in that: The compensation oil cylinder (23) is provided with a travel sensor (52) for sensing the displacement of the piston rod (233).

10. The mud pipeline compensation device according to claim 4, characterized in that: A pressure reducing valve (53) is connected between the oil supply pipeline (31) and the oil return pipeline (32).

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