A Retractable TBM and Its Hydraulic Control System for the Retraction Posture of the Front Shield

Abstract

The present invention discloses a hydraulic control system for the retraction attitude of the front shield, which relates to the technical field of tunneling machines and includes a plurality of propulsion cylinders connected circumferentially between the front shield and the main shield, an oil pump, a first reversing valve, a second reversing valve, and a return oil backpressure regulating valve group; the first reversing valve is used to control the connection between the oil pump and the rodless cavity or the rod cavity of each propulsion cylinder; each second reversing valve is respectively connected between the first reversing valve and each propulsion cylinder and is used to introduce pressure oil into the rodless cavity of the corresponding propulsion cylinder, or to connect the rodless cavity with the fuel tank when the oil pump is connected to the rod cavity of each propulsion cylinder; the return oil backpressure regulating valve group is connected between each second reversing valve and the fuel tank and is used to regulate the return oil backpressure of the rodless cavity of each propulsion cylinder. The present invention can conveniently and efficiently realize the control and adjustment of the retraction attitude of the front shield, improve the control accuracy, prevent the front shield from jamming, and reduce the manual labor intensity at the same time. The present invention also discloses a retractable TBM, and its beneficial effects are as described above.

Description

Technical Field

[0001] The present invention relates to the technical field of roadheaders, and particularly to a hydraulic control system for the retraction attitude of a front shield. The present invention also relates to a retractable TBM. Background Art

[0002] Open TBMs (Tunnel Boring Machines) are everywhere in the construction of underground projects such as highway tunnels, railway tunnels, and water diversion tunnels. The complex excavation paths and geological environments pose new challenges to TBM construction personnel and construction equipment.

[0003] Conventional tunnels usually have only a single inlet and outlet. However, during the excavation of some special hard rock tunnels, when one branch tunnel is completed and the excavation of the next branch tunnel is carried out, the TBM needs to be retracted to a specified position and then adjusted in direction to complete the excavation of the next branch tunnel. During the retraction of the TBM, since the rock friction resistances around the front shield are different and the friction resistance is in a real-time changing stage, the load resistances of the propulsion cylinders distributed around are different during the retraction process, and they are also in a real-time changing state. This causes the propulsion cylinders with smaller load resistances to retract faster, while the propulsion cylinders with larger load resistances retract slower or even have a retraction speed of zero. Once this situation occurs, the front shield of the TBM is extremely likely to be stuck in the tunnel and cannot complete the normal retraction operation.

[0004] Currently, the existing retractable TBMs adopt a parallel connection mode of fixed damping and variable damping on the oil return path of the propulsion cylinders during retraction, artificially increasing the load resistance when the propulsion cylinders with smaller rock wall friction resistances retract, so that the load resistances of the propulsion cylinders distributed around during retraction meet the retraction attitude of the front shield of the TBM, thereby completing the normal retraction of the entire TBM. However, this propulsion hydraulic system has the following problems: Since the load resistances of the propulsion cylinders distributed around are in a real-time changing state during retraction, on-site operators need to repeatedly adjust the size of the variable damping, resulting in a large labor intensity for on-site construction personnel, difficult operation, greatly reduced construction efficiency, and it is also difficult to accurately adjust the variable damping, with a low adjustment accuracy and inaccurate control of the retraction attitude of the front shield.

[0005] Therefore, how to conveniently and efficiently achieve the control and adjustment of the retraction attitude of the front shield, improve the control accuracy, prevent the front shield from being stuck, and at the same time reduce the manual labor amount is a technical problem faced by those skilled in the art. Summary of the Invention

[0006] The object of the present invention is to provide a hydraulic control system for the retraction attitude of the front shield, which can conveniently and efficiently achieve the control and adjustment of the retraction attitude of the front shield, improve the control accuracy, prevent the front shield from jamming, and reduce the manual labor intensity at the same time. Another object of the present invention is to provide a retractable TBM.

[0007] To solve the above technical problems, the present invention provides a hydraulic control system for the retraction attitude of the front shield, which includes a plurality of propulsion cylinders circumferentially connected between the front shield and the main shield, and also includes an oil pump, a first reversing valve, a plurality of second reversing valves, and a return oil backpressure regulating valve group;

[0008] The first reversing valve is used to control the communication between the oil pump and the rod chamber or the rodless chamber of each propulsion cylinder;

[0009] Each of the second reversing valves is respectively connected between the first reversing valve and each propulsion cylinder, and is used to introduce the pressure oil from the first reversing valve into the rodless chamber of the corresponding propulsion cylinder, or to connect the rodless chamber of each propulsion cylinder with the fuel tank when the oil pump is in communication with the rod chamber of each propulsion cylinder;

[0010] The return oil backpressure regulating valve group is connected between each second reversing valve and the fuel tank, and is used to regulate the return oil backpressure of the rodless chamber of each propulsion cylinder.

[0011] Preferably, the return oil backpressure regulating valve group includes a pilot-operated relief valve and a proportional relief valve;

[0012] The inlet of the pilot-operated relief valve is communicated with the return oil port of the corresponding second reversing valve, the outlet of the pilot-operated relief valve is communicated with the fuel tank, the pilot control oil port of the pilot-operated relief valve is communicated with the inlet of the proportional relief valve, and the outlet of the proportional relief valve is communicated with the fuel tank.

[0013] Preferably, the return oil backpressure regulating valve group further includes a pressure sensor;

[0014] The pressure sensor is connected between the return oil port of the corresponding second reversing valve and the inlet of the pilot-operated relief valve.

[0015] Preferably, the return oil backpressure regulating valve group further includes a check valve;

[0016] The check valve is connected between the return oil port of the corresponding second reversing valve and the fuel tank, and is used to make the fuel tank conduct unidirectionally to the rodless chamber of the corresponding propulsion cylinder.

[0017] Preferably, the propulsion oil cylinder comprises an A-zone oil cylinder group distributed at the top of the front shield, a B-zone oil cylinder group distributed at one side of the front shield, a C-zone oil cylinder group distributed at the bottom of the front shield, and a D-zone oil cylinder group distributed at the other side of the front shield; the oil return backpressure regulating valve group is connected between each of the second reversing valves corresponding to the A-zone oil cylinder group, the B-zone oil cylinder group, and the D-zone oil cylinder group and the oil tank.

[0018] Preferably, the first reversing valve has at least two working positions, its oil inlet is communicated with the oil pump, its oil return port is communicated with the oil tank, its first working oil port is communicated with the rodless cavities of the propulsion oil cylinders, and its second working oil port is communicated with the oil inlets of the second reversing valves;

[0019] When the first reversing valve is in the first working position, its oil inlet is communicated with its first working oil port, and its oil return port is communicated with its second working oil port;

[0020] When the first reversing valve is in the second working position, its oil inlet is communicated with its second working oil port, and its oil return port is communicated with its first working oil port.

[0021] Preferably, the second reversing valve has at least two working positions, its oil inlet is communicated with the second working oil port of the first reversing valve, its oil return port is communicated with the oil tank, its first working oil port is communicated with the rodless cavities of the propulsion oil cylinders, and its second working oil port is blocked;

[0022] When the second reversing valve is in the first working position, its oil inlet is communicated with its first working oil port, and its oil return port is communicated with its second working oil port;

[0023] When the second reversing valve is in the second working position, its oil inlet is communicated with its second working oil port, and its oil return port is communicated with its first working oil port.

[0024] The present invention further provides a retractable TBM, which comprises a front shield and a main shield, and further comprises the front shield retracting attitude hydraulic control system as described in any one of the above.

[0025] The hydraulic control system for the forward shield retraction attitude provided by the present invention mainly includes propulsion cylinders, an oil pump, a first reversing valve, a second reversing valve, and a return oil backpressure regulating valve group. Among them, multiple propulsion cylinders are provided, and each propulsion cylinder is connected between the forward shield of the TBM and the main shield (or the tightening shield) of the TBM, and each propulsion cylinder is distributed along the circumferential direction of the forward shield, so as to conveniently apply loads to various positions on the circumference of the forward shield simultaneously. The oil pump is mainly used to provide pressurized oil. The first reversing valve is connected between the oil pump and each propulsion cylinder, and is mainly used to switch the oil circuit of the oil pump, so that the pressurized oil enters the rod chamber or the non-rod chamber of each propulsion cylinder. Multiple second reversing valves are provided, and each second reversing valve is respectively connected between the first reversing valve and the corresponding propulsion cylinder, which is equivalent to the secondary switching control of the oil circuit, and is mainly used to continue introducing the pressurized oil led out from the first reversing valve into the non-rod chamber of each propulsion cylinder, so that the piston rod extends to realize the retraction movement of the main shield; or when the oil pump is communicated with the rod chamber of each propulsion cylinder and the piston rod retracts, it is used to communicate the non-rod chamber of each propulsion cylinder with the fuel tank to realize the retraction movement of the forward shield. The return oil backpressure regulating valve group is the core component, and generally multiple are also provided. Specifically, it is connected between each second reversing valve and the fuel tank, and is mainly used to adjust the return oil backpressure of the non-rod chamber during the process of the piston rod of the propulsion cylinder retracting and the pressurized oil in the non-rod chamber flowing back to the fuel tank through the second reversing valve (return oil circuit), so as to use this return oil backpressure to control the pressure of the non-rod chamber of the corresponding propulsion cylinder and form a resistance or damping effect on the retraction movement of the piston rod. The greater the return oil backpressure, the stronger the damping effect, and vice versa. Furthermore, each propulsion cylinder forms a load resistance with controllable direction and magnitude on the forward shield during the retraction process to meet the requirements of the forward shield retraction attitude. In this way, the hydraulic control system for the forward shield retraction attitude provided by the present invention realizes the retraction damping control of each position on the circumference of the forward shield through the adjustment of the return oil circuit pressure of each propulsion cylinder during the retraction movement by the return oil backpressure regulating valve group, can conveniently and efficiently realize the control and adjustment of the forward shield retraction attitude, improve the control accuracy, prevent the forward shield from jamming, and at the same time reduce the manual labor volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0027] Figure 1 It is a schematic diagram of the overall structure of a specific embodiment provided by the present invention.

[0028] Figure 2 It is a schematic diagram of the shield structure of the TBM.

[0029] Among them, Figure 1 — Figure 2 In:

[0030] Front shield—1, main shield—2, propulsion cylinder—3, oil pump—4, first reversing valve—5, second reversing valve—6, pilot relief valve—7, proportional relief valve—8, pressure sensor—9, check valve—10, stabilizer cylinder—11, shoe cylinder—12. Specific embodiments

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] Please refer to Figure 1 , Figure 1 which is a schematic diagram of the overall structure of a specific embodiment provided by the present invention.

[0033] In a specific embodiment provided by the present invention, the hydraulic control system for the retraction attitude of the front shield includes a propulsion cylinder 3, an oil pump 4, a first reversing valve 5, a second reversing valve 6, and a return oil backpressure regulating valve group.

[0034] Among them, a plurality of propulsion cylinders 3 are provided, and each propulsion cylinder 3 is connected between the front shield 1 of the TBM and the main shield 2 (or the tightening shield) of the TBM, and each propulsion cylinder 3 is distributed along the circumferential direction of the front shield 1, which can conveniently apply loads to various positions on the circumference of the front shield 1 at the same time.

[0035] Generally, for a retractable TBM, each propulsion cylinder 3 can be partitioned and controlled according to conventional partitioning rules. For example, according to the connection positions of each propulsion cylinder 3 on the front shield 1, each propulsion cylinder 3 can be divided into four groups, namely: the A-area cylinder group distributed on the top of the front shield 1, the B-area cylinder group distributed on one side (such as the right side) of the front shield 1, the C-area cylinder group distributed on the bottom of the front shield 1, and the D-area cylinder group distributed on the other side (such as the left side) of the front shield 1. Among them, during the retraction process of the TBM, the C-area cylinder group has the largest load resistance when retracting, the B / D-area cylinder groups are the second, and the A-area cylinder group is the smallest. Thus, generally, it is only necessary to set a return oil backpressure regulating valve group in the propulsion cylinders 3 in the three partitions A / B / D to increase the load resistance, so that the load resistance when the propulsion cylinders 3 in all partitions retract meets the normal retraction attitude of the front shield 1 of the TBM. Of course, it is also feasible to set a return oil backpressure regulating valve group for all the propulsion cylinders 3 in all partitions.

[0036] The oil pump 4 is mainly used to provide pressurized oil.

[0037] The first reversing valve 5 is connected between the oil pump 4 and each propulsion cylinder 3, and is mainly used to switch the oil circuit of the oil pump 4 so that the pressurized oil enters the rod chamber or the rodless chamber of each propulsion cylinder 3.

[0038] There are multiple second reversing valves 6, and each second reversing valve 6 is respectively connected between the first reversing valve 5 and each corresponding propulsion cylinder 3. This is equivalent to a secondary switching control of the oil circuit, and is mainly used to continue introducing the pressurized oil led out from the first reversing valve 5 into the rodless chamber of each propulsion cylinder 3, so that the piston rod extends to realize the retraction movement of the main shield 2; or when the oil pump 4 is connected to the rod chamber of each propulsion cylinder 3 and the piston rod retracts, it is used to connect the rodless chamber of each propulsion cylinder 3 to the fuel tank to realize the retraction movement of the front shield 1.

[0039] The oil return backpressure regulating valve group is the core component, and generally there are also multiple ones. Specifically, it is connected between each second reversing valve 6 and the fuel tank, and is mainly used to regulate the oil return backpressure of the rodless chamber during the process of the piston rod of the propulsion cylinder 3 retracting and the pressurized oil in the rodless chamber flowing back to the fuel tank through the second reversing valve 6 (oil return circuit), so as to use this oil return backpressure to control the pressure of the rodless chamber of the corresponding propulsion cylinder 3 and form a resistance or damping effect on the retraction movement of the piston rod. The greater the oil return backpressure, the stronger the damping effect, and vice versa. Furthermore, it enables each propulsion cylinder 3 to form a load resistance with controllable direction and magnitude on the front shield 1 during the retraction process, meeting the requirements of the retraction attitude of the front shield 1.

[0040] In this way, the front shield retraction attitude hydraulic control system provided by this embodiment realizes the retraction damping control of each position in the circumferential direction of the front shield 1 by regulating the oil return circuit pressure of each propulsion cylinder 3 during the retraction movement through the oil return backpressure regulating valve group, can conveniently and efficiently realize the retraction attitude control and adjustment of the front shield 1, improve the control accuracy, prevent the front shield 1 from jamming, and at the same time reduce the manual labor amount.

[0041] In an optional embodiment regarding the oil return backpressure regulating valve group, the oil return backpressure regulating valve group specifically includes a pilot-operated relief valve 7 and a proportional relief valve 8, which are used in combination. Among them, the inlet of the pilot-operated relief valve 7 is connected to the corresponding second reversing valve 6, specifically communicated with the oil return port on the second reversing valve 6, and the outlet of the pilot-operated relief valve 7 is communicated with the fuel tank. At the same time, the pilot-operated relief valve 7 has a pilot control oil port, which is communicated with the inlet of the proportional relief valve 8, and the outlet of the proportional relief valve 8 is communicated with the fuel tank.

[0042] With such a setting, the overflow pressure of the pilot overflow valve 7 is directly controlled by the proportional overflow valve 8, and the proportional overflow valve 8 can conveniently and proportionally control the pressure of the pilot control oil port of the pilot overflow valve 7 through electromagnetic control or other means. Since when the propulsion cylinder 3 retracts, its oil return path needs to pass through the pilot overflow valve 7 after passing through the second reversing valve 6 before flowing back to the fuel tank, the pressure of the oil return path must rise to the overflow pressure of the pilot overflow valve 7 in order to smoothly flow back to the fuel tank through the pilot overflow valve 7.

[0043] It can be seen that the overflow pressure of the pilot overflow valve 7 is the oil return back pressure of the oil return path of the propulsion cylinder 3 and is also the pressure of the rodless cavity of the propulsion cylinder 3. Since the overflow pressure of the pilot overflow valve 7 is determined by the proportional overflow valve 8, only by adjusting the proportional coefficient of the proportional overflow valve 8 can the oil return back pressure of the rodless cavity of the propulsion cylinder 3 be conveniently adjusted, and thus the damping effect formed by each propulsion cylinder 3 on the circumferential positions of the front shield 1 can be conveniently adjusted.

[0044] Of course, the specific structure of the oil return back pressure regulating valve group is not limited to the combined structure of the aforementioned pilot overflow valve and the proportional overflow valve 8. For example, it can also be replaced by a large-flow inverse proportional electro-hydraulic proportional overflow valve 8.

[0045] To facilitate accurately grasping the change of the oil return back pressure of the rodless cavity of the propulsion cylinder 3, a pressure sensor 9 is added in this embodiment. Specifically, the pressure sensor 9 is connected between the oil return port of the corresponding second reversing valve 6 and the oil inlet of the pilot overflow valve 7, and is mainly used to detect the oil return path pressure of the propulsion cylinder 3, that is, the oil return back pressure. With such a setting, through the feedback data of the pressure sensor 9, the magnitude of the artificially increased load resistance of each propulsion cylinder 3 in each partition can be monitored in real time. Combining with the attitude of the front shield 1, it can provide a real-time basis for the on-site operator to adjust the attitude of the front shield 1 in the next step.

[0046] In summary, in this embodiment, a small-flow proportional overflow valve 8 is used to control the pilot oil pressure of the pilot overflow valve, so as to realize continuously adjustable oil return back pressure during the retraction process of the propulsion cylinder 3 (that is, continuously adjustable load resistance when the propulsion cylinder 3 retracts). During this period, the magnitude of the oil return back pressure is monitored in real time through the pressure sensor 9, providing a data basis for the next operation of the TBM operator. At the same time, through the data of the stroke sensor integrated on the propulsion cylinder 3, the TBM operator can also real-time master the basic attitude of the front shield 1 when it retreats in the control room. Combining with the feedback data of the pressure sensor 9 and adjusting the pressure control knob of the proportional overflow valve 8, the attitude of the front shield 1 when it retreats can be adjusted completely according to the will of the TBM operator, so as to complete the normal retraction of the whole TBM.

[0047] In addition, considering that in the prior art, the selection of fixed damping and variable damping sizes requires the accumulation of preliminary test data, which poses higher requirements for the comprehensive capabilities of designers. If the selection is inappropriate, the normal retraction of the entire TBM cannot be completed. However, this embodiment can reduce the requirements for the designers' own capabilities without the need for the accumulation of preliminary test data. Designers only need to select and design the rated flow rate and rated pressure of the pilot-operated relief valve and the proportional relief valve 8.

[0048] Considering that during the retraction of the front shield 1, the telescopic rods of some of the propulsion cylinders 3 may have passive extension strokes due to the telescopic movements of the other propulsion cylinders 3. For this reason, a check valve 10 is added in this embodiment. Specifically, the check valve 10 is connected between the oil return port of the corresponding second reversing valve 6 and the fuel tank, mainly used to achieve one-way conduction from the fuel tank to the second reversing valve 6, and further achieve one-way conduction from the fuel tank to the rodless cavity of the propulsion cylinder 3. Thus, when the piston rod of a certain propulsion cylinder 3 has a passive extension stroke, the rodless cavity of this propulsion cylinder 3 can automatically replenish oil from the fuel tank to prevent damage to the propulsion cylinder 3 caused by the inability to replenish oil in time during passive extension.

[0049] In an alternative embodiment regarding the first reversing valve 5 and the second reversing valve 6, the first reversing valve 5 has at least four oil ports, namely an oil inlet port (illustrated as port P), an oil return port (illustrated as port T), a first working oil port (illustrated as port A), a second working oil port (illustrated as port B), and at least two working positions.

[0050] Similarly, the second reversing valve 6 is similar to the first reversing valve 5. The second reversing valve 6 has at least four oil ports, namely an oil inlet port (illustrated as port P), an oil return port (illustrated as port T), a first working oil port (illustrated as port A), a second working oil port (illustrated as port B), and at least two working positions.

[0051] Among them, the oil inlet port of the first reversing valve 5 is connected to the oil pump 4, the oil return port of the first reversing valve 5 is connected to the fuel tank, the first working oil port of the first reversing valve 5 is connected to the rod cavities of each propulsion cylinder 3, and the second working oil port of the first reversing valve 5 is connected to the oil inlet ports of each second reversing valve 6.

[0052] The oil inlet ports of each second reversing valve 6 are all connected to the second working oil port of the first reversing valve 5. The oil return ports of each second reversing valve 6 are all connected to the fuel tank or connected to the fuel tank after passing through the oil return backpressure regulating valve group. The first working oil ports of each second reversing valve 6 are respectively connected to the rodless cavities of each propulsion cylinder 3 in the corresponding partition, and the second working oil ports of each second reversing valve 6 are all blocked (or this second working oil port can also be not provided).

[0053] Meanwhile, when the first reversing valve 5 operates in the first working position (the right working position as shown in the figure), its oil inlet is communicated with its first working oil port, and its oil return port is communicated with its second working oil port; when the first reversing valve 5 operates in the second working position (the left working position as shown in the figure), its oil inlet is communicated with its second working oil port, and its oil return port is communicated with its first working oil port.

[0054] Similarly, when each second reversing valve 6 operates in the first working position (the right working position as shown in the figure), its oil inlet is communicated with its first working oil port, and its oil return port is communicated with its second working oil port; when the second reversing valve 6 operates in the second working position (the left working position as shown in the figure), its oil inlet is communicated with its second working oil port, and its oil return port is communicated with its first working oil port.

[0055] Thus, when the first reversing valve 5 is in the second working position and each second reversing valve 6 is in the first working position, the pressure oil first passes through the P - B port of the first reversing valve 5, then through the P - A port of the second reversing valve 6, and enters the rodless cavities of each propulsion cylinder 3 to push the piston rod out. All the oil in the rod - end cavity flows back to the oil tank through the A - T port of the first reversing valve 5; when the first reversing valve 5 is in the first working position and each second reversing valve 6 is in the second working position, the pressure oil directly reaches the rod - end cavities of each propulsion cylinder 3 through the P - A port of the first reversing valve 5 to push the piston rod back. The oil in the rodless cavity flows back to the oil tank through the A - T port of the second reversing valve 6, or flows back to the oil tank after passing through the oil return back - pressure regulating valve group.

[0056] As Figure 2 shown, Figure 2 it is a schematic diagram of the shield structure of the TBM.

[0057] This embodiment also provides a retractable TBM, which mainly includes a front shield 1, a main shield 2, and a front - shield retraction attitude hydraulic control system. Among them, the specific content of the front - shield retraction attitude hydraulic control system is the same as the above - related content and will not be elaborated here.

[0058] Generally, the action process of the retractable TBM to complete the whole - machine retraction process can be simplified into the following steps: First, the stabilizer cylinder 11 installed on the front shield 1 extends and tightens the surrounding rock wall, and at this time, the shoe cylinder 12 on the main shield 2 is in the retracted state; then, each propulsion cylinder 3 extends, and uses the reaction force of the rock wall to make the main shield 2 complete a partial retraction action; next, the shoe cylinder 12 installed on the main shield 2 extends and tightens the surrounding rock wall, and at this time, the stabilizer cylinder 11 is in the retracted state; finally, each propulsion cylinder 3 retracts to drive the front shield 1 (and parts such as the cutter head) to complete the retraction action.

[0059] During the retraction process of the retractable TBM, due to the different load resistances on the propulsion cylinders 3 in each partition (the aforementioned partitions A, B, C, and D), the following situations may occur, and the operator needs to adjust the oil return backpressure control knobs of the propulsion cylinders 3 in partitions A, B, and D (i.e., the pressure adjustment knobs of the proportional overflow valve 8) in the control room to correct the retraction attitude of the front shield 1:

[0060] 1. The front shield 1 has a raising attitude, that is, the propulsion cylinder 3 in area A retracts relatively faster. At this time, mainly increase the oil return backpressure of the propulsion cylinder 3 in area A to reduce the retraction speed of the propulsion cylinder 3. Secondly, appropriately adjust the oil return backpressure of the propulsion cylinders 3 in areas B / D for assistance;

[0061] 2. The front shield 1 has a lowering attitude, that is, the propulsion cylinder 3 in area A retracts relatively slower. At this time, mainly reduce the oil return backpressure of the propulsion cylinder 3 in area A to increase the retraction speed of the propulsion cylinder 3. Secondly, appropriately adjust the oil return backpressure of the propulsion cylinders 3 in areas B / D for assistance.

[0062] 3. The front shield 1 has a left-turning attitude, that is, the propulsion cylinder 3 in area D retracts relatively faster. At this time, mainly reduce the oil return backpressure of the propulsion cylinder 3 in area B and increase the oil return backpressure of the propulsion cylinder 3 in area D to increase the retraction speed of the propulsion cylinder 3 in area B and reduce the retraction speed of the propulsion cylinder 3 in area D. Secondly, appropriately adjust the oil return backpressure of the propulsion cylinder 3 in area A for assistance;

[0063] 4. The front shield 1 has a right-turning attitude, that is, the propulsion cylinder 3 in area D retracts relatively slower. At this time, mainly increase the oil return backpressure of the propulsion cylinder 3 in area B and reduce the oil return backpressure of the propulsion cylinder 3 in area D to reduce the retraction speed of the propulsion cylinder 3 in area B and increase the retraction speed of the propulsion cylinder 3 in area D. Secondly, appropriately adjust the oil return backpressure of the propulsion cylinder 3 in area A for assistance.

[0064] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydraulic control system for the retraction attitude of the front shield, comprising a plurality of propulsion cylinders (3) circumferentially connected between the front shield (1) and the main shield (2), characterized in that, It further includes an oil pump (4), a first reversing valve (5), a plurality of second reversing valves (6), and a return oil backpressure regulating valve group; The first reversing valve (5) is used to control the connection between the oil pump (4) and the rod chambers or rodless chambers of the respective propulsion cylinders (3); Each of the second reversing valves (6) is used to introduce pressure oil from the first reversing valve (5) into the rodless chamber of the corresponding propulsion cylinder (3), or when the oil pump (4) is connected to the rod chambers of the respective propulsion cylinders (3), to connect the rodless chambers of the respective propulsion cylinders (3) to the fuel tank; The propulsion cylinders (3) include an A-area cylinder group distributed at the top of the front shield (1), a B-area cylinder group distributed on one side of the front shield (1), a C-area cylinder group distributed at the bottom of the front shield (1), and a D-area cylinder group distributed on the other side of the front shield (1); there are a total of four second reversing valves (6), with one second reversing valve (6) provided in each partition, and there are a total of three return oil backpressure regulating valve groups, and each of the return oil backpressure regulating valve groups is connected between the respective second reversing valves (6) corresponding to the A-area cylinder group, the B-area cylinder group, and the D-area cylinder group and the fuel tank, for regulating the return oil backpressure of the rodless chambers of the respective propulsion cylinders (3) in the corresponding partition; The first reversing valve (5) has at least two working positions, and its oil inlet is connected to the oil pump (4), its oil return port is connected to the fuel tank, its first working oil port is connected to the rod chambers of the respective propulsion cylinders (3), and its second working oil port is connected to the oil inlets of the respective second reversing valves (6); When the first reversing valve (5) is in the first working position, its oil inlet is connected to its first working oil port, and its oil return port is connected to its second working oil port; When the first reversing valve (5) is in the second working position, its oil inlet is connected to its second working oil port, and its oil return port is connected to its first working oil port; The second reversing valve (6) has at least two working positions, and its oil inlet is connected to the second working oil port of the first reversing valve (5), its oil return port is connected to the fuel tank, its first working oil port is respectively connected to the rodless chambers of the respective propulsion cylinders (3) in the corresponding partition, and its second working oil port is blocked; When the second reversing valve (6) is in the first working position, its oil inlet is connected to its first working oil port, and its oil return port is connected to its second working oil port; When the second reversing valve (6) is in the second working position, its oil inlet is connected to its second working oil port, and its oil return port is connected to its first working oil port.

2. The hydraulic control system for the front shield retraction posture according to claim 1, characterized in that, The return oil backpressure regulating valve group includes a pilot-operated relief valve (7) and a proportional relief valve (8); The oil inlet of the pilot-operated relief valve (7) is connected to the oil return port of the corresponding second reversing valve (6), the oil outlet of the pilot-operated relief valve (7) is connected to the fuel tank, the pilot control oil port of the pilot-operated relief valve (7) is connected to the oil inlet of the proportional relief valve (8), and the oil outlet of the proportional relief valve (8) is connected to the fuel tank.

3. The hydraulic control system for the front shield retraction attitude according to claim 2, characterized in that, The return oil backpressure regulating valve group further includes a pressure sensor (9); The pressure sensor (9) is connected between the oil return port of the corresponding second reversing valve (6) and the oil inlet port of the pilot-operated relief valve (7).

4. The hydraulic control system for the front shield retraction attitude according to claim 3, characterized in that The oil return back pressure regulating valve group further includes a check valve (10); The check valve (10) is connected between the oil return port of the corresponding second reversing valve (6) and the oil tank, and is used to make the oil tank conduct unidirectionally to the rodless cavity of the corresponding propulsion cylinder (3).

5. A retractable TBM, comprising a front shield (1) and a main shield (2), characterized in that, It further includes a front shield retraction attitude hydraulic control system according to any one of claims 1-4.

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