Hydraulic system of non-circular heading machine blind area cutting device and control method

Abstract

The invention discloses a hydraulic system of a non-circular heading machine blind area cutting device and a control method. The problems that in the prior art, a non-circular heading machine is low in blind area processing efficiency in construction and the like are solved. The hydraulic system comprises roller cutting tools arranged in excavation blind areas of two adjacent circular cutter heads, and the roller cutting tools are driven by a closed hydraulic control system; the closed hydraulic control system comprises a pump set, a port A and a port B of the pump set are respectively connected with a bidirectional constant displacement motor set, and an oil return control valve set is arranged between the port A and the port B of the bidirectional constant displacement motor set; the pump set comprises a two-way variable pump and an oil supplementing pump. A first part of replenished oil of the oil replenishment pump adjusts the output direction and the displacement of the two-way variable pump through a displacement adjusting device; and the second part of supplementary oil of the oil supplementing pump is used for supplementing oil to the pump set through the oil supplementing valve set. The hydraulic control system structure of the blind area processing device is small in soil disturbance, small in section overexcavation amount and high in construction efficiency, the advancing resistance of the heading machine can be reduced, and the accuracy of heading attitude control of the heading machine is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of non-circular tunnel boring machines, in particular to a blind area cutting system for non-circular tunnel boring machines. Background Art

[0002] Non-circular tunnel boring machines have attracted more and more attention from scholars due to their high cross-sectional utilization rate, but the problem of blind excavation spots in non-circular tunnel boring machines has not been effectively solved. During the excavation process, the soil in the blind excavation spots cannot be crushed by the cutterhead of the non-circular tunnel boring machine, which will increase the forward resistance of the tunnel boring machine. At the same time, the unbroken soil will also cause the head posture of the non-circular tunnel boring machine to shift. The blind excavation spots have many negative impacts on the construction of non-circular tunnel boring machines, and there is no good solution in the relevant technology. Therefore, the technology for handling blind excavation spots of non-circular tunnel boring machines is of great significance. The existing related technologies generally use the following three methods to handle blind spots:

[0003] 1. A motor-driven crank rocker floating cutterhead structure is used. However, compared with general non-circular tunnel boring machines, this solution has problems such as large soil disturbance, large force on the central rotating axis and difficulty in calibration. In addition, the floating cutterhead is easily damaged during construction and difficult to repair.

[0004] Second, change the structural layout of the cutterhead and the shell, design the cross-section into a non-standard rectangular cross-section, increase the fillet radius at the right angle, and design the rectangular side into an elliptical structure, thereby increasing the diameter of a single cutterhead and reducing the blind area. However, the above method of changing the structural layout has the following problems: the equipment modification is difficult, the fillet radius is increased, the available space of the formed tunnel is reduced, the project cost is high, and the posture of the rectangular jacking machine is greatly affected during construction, resulting in a high failure rate.

[0005] 3. Before the construction of the non-circular tunnel boring machine, the position of the blind area of ​​the excavation on the surface to be excavated is pre-determined according to the cutter layout diagram of the non-circular tunnel boring machine, and holes are drilled manually in the blind area of ​​the excavation. This method has high risks, low safety factors and low construction efficiency.

[0006] In view of the deficiencies in the above-mentioned background technology, it is necessary to develop a hydraulic drive system and control method for a blind spot processing device of a non-circular tunnel boring machine to solve the problem of blind spot processing of the non-circular tunnel boring machine during construction. Summary of the invention

[0007] In view of the deficiencies in the above-mentioned background technology, the present invention proposes a hydraulic system and a control method for a blind spot cutting device of a non-circular tunnel boring machine, which solves the problem of low efficiency in blind spot processing of non-circular tunnel boring machines during construction in the prior art.

[0008] The technical solution of the present invention is implemented as follows: a hydraulic system of a blind spot cutting device of a non-circular tunnel boring machine includes a roller cutting tool arranged in the excavation blind spot of two adjacent circular cutter discs, and the roller cutting tool is driven by a closed hydraulic control system; the closed hydraulic control system includes a pump group, and the A port and the B port of the pump group are respectively connected to the bidirectional quantitative motor group, and a return oil control valve group is arranged between the A port and the B port of the bidirectional quantitative motor group; the pump group includes a bidirectional variable pump and an oil replenishment pump; the first part of the supplementary oil of the oil replenishment pump adjusts the output direction and displacement of the bidirectional variable pump through a displacement regulating device; the second part of the supplementary oil of the oil replenishment pump replenishes the pump group through the oil replenishment valve group.

[0009] Among them, the oil replenishment pump sucks oil from the S port of the pump group, the oil flowing out of the oil replenishment pump enters the first filter through the Fe port of the pump group, and then enters the oil replenishment pipeline in the pump group through the Fa port of the pump group. The part of the oil in the oil replenishment pipeline that enters the displacement regulating device forms the first part of replenishment oil, and the part of the oil in the oil replenishment pipeline that enters the oil replenishment valve group forms the second part of replenishment oil.

[0010] Further preferably, the displacement regulating device includes an electric proportional reversing valve and a regulating cylinder controlling the swash plate of a bidirectional variable pump; the first part of the supplementary oil controls the extension direction and extension amount of the regulating cylinder through the electric proportional reversing valve; and a motor is connected to the bidirectional variable pump.

[0011] Further preferably, the oil replenishing valve group includes a first oil replenishing valve and a second oil replenishing valve arranged in parallel, and when the A port of the pump group outputs high-pressure oil, the second part of the replenishing oil is replenished through the first oil replenishing valve and the return oil pipeline entering the B port; when the B port of the pump group outputs high-pressure oil, the second part of the replenishing oil is replenished through the second oil replenishing valve and the return oil pipeline entering the A port.

[0012] Further preferably, the first oil replenishment valve includes a first check valve and a first relief valve arranged in parallel, the first relief valve is connected to the oil circuit leading to the pump group B port; the second oil replenishment valve includes a second check valve and a second relief valve arranged in parallel; the second relief valve is connected to the oil circuit leading to the pump group A port. A third relief valve and a pressure sensor are connected to the oil circuit of the second part of the replenishment oil.

[0013] Further preferably, a unloading branch I is provided between the pipeline leading to port A and the pipeline leading to port B of the pump group, a shuttle valve is provided on the unloading branch, the shuttle valve is connected to a pressure cut-off valve, and the pressure cut-off valve is connected to the electric proportional reversing valve of the displacement regulating device through the unloading branch II.

[0014] Further preferably, the bidirectional quantitative motor group includes a first bidirectional quantitative motor and a second bidirectional quantitative motor arranged in parallel, and the first bidirectional quantitative motor and the second bidirectional quantitative motor provide rotational power for the roller cutting tool; the return oil control valve group includes a hydraulically controlled reversing valve and a fourth overflow valve arranged in series, and a throttling hole is provided on the pipeline between the hydraulically controlled reversing valve and the fourth overflow valve.

[0015] A control method for the hydraulic system of a blind spot cutting device of a non-circular tunnel boring machine, starting the pump group, drawing out the first part of the supplementary oil from the supplementary oil pump as control oil, and the control oil entering the electric proportional reversing valve and regulating cylinder to select the inlet and outlet oil ports and control the displacement of the bidirectional variable pump.

[0016] When port A of the pump group is the high-pressure oil outlet and port B is the low-pressure oil inlet, the high-pressure oil in the two-way variable pump enters port A of the two-way quantitative motor group and the hydraulically controlled reversing valve through port A. At this time, the two-way quantitative motor group drives the roller cutting tool to rotate forward, and the spool of the hydraulically controlled reversing valve moves to connect the throttling hole with the fourth overflow valve; the oil after entering the two-way quantitative motor group flows out through port B of the two-way quantitative motor group; part of the oil flowing out through port B of the two-way quantitative motor group flows back to the pump group through port B of the pump group to form a closed hydraulic system, and part of it flows back to the oil tank through the hydraulically controlled reversing valve, the throttling hole and the fourth overflow valve, leading part of the hot oil on the return oil side out of the closed hydraulic system; at the same time, part of the second part of the replenishment oil of the oil replenishment pump flows through the first The first check valve of an oil replenishment valve merges with the oil flowing back from the B port of the pump group to replenish the oil; a part of the second part of the replenishment oil of the oil replenishment pump overflows through the third overflow valve, and by setting the pressure of the third overflow valve, a pressure difference △P is formed with the fourth overflow valve, and the oil change flow in the closed hydraulic system is adjusted according to the pressure difference flow formula of the throttle hole; when the pressure of the high-pressure oil flowing from the pump group to the A port exceeds the set value of the second overflow valve, overflow through the second overflow valve to form a first-level protection; when the pressure of the high-pressure oil flowing from the pump group to the A port reaches the set value of the second overflow valve and continues to rise, the high-pressure side oil is selected through the shuttle valve and acts on the pressure cut-off valve to reduce or unload the pressure of the high-pressure oil, forcing the pump displacement to be reduced to form a second-level protection.

[0017] When the B port of the pump group is the high-pressure oil outlet and the A port is the low-pressure oil inlet, the high-pressure oil in the two-way variable pump enters the B port of the two-way quantitative motor group and the hydraulically controlled reversing valve through the B port. At this time, the two-way quantitative motor group drives the roller cutting tool to rotate in the opposite direction, and the spool of the hydraulically controlled reversing valve moves to connect the throttling hole with the fourth overflow valve; the oil after entering the two-way quantitative motor group flows out through the A port of the two-way quantitative motor group; part of the oil flowing out through the A port of the two-way quantitative motor group flows back to the pump group through the A port of the pump group to form a closed hydraulic system, and part of it flows back to the oil tank through the hydraulically controlled reversing valve, the throttling hole and the fourth overflow valve, and part of the hot oil on the return oil side is led out of the closed hydraulic system; at the same time, part of the second part of the replenishment oil of the oil replenishment pump is replenished through the first The second check valve of the second oil replenishment valve merges with the oil flowing back from the A port of the pump group to replenish the oil; a part of the second part of the replenishment oil of the oil replenishment pump overflows through the third overflow valve, and by setting the pressure of the third overflow valve, a pressure difference △P is formed with the fourth overflow valve, and the oil change flow in the closed hydraulic system is adjusted according to the pressure difference flow formula of the throttle hole; when the pressure of the high-pressure oil flowing from the pump group to the B port exceeds the setting value of the first overflow valve, overflow through the first overflow valve to form a first-level protection; when the pressure of the high-pressure oil flowing from the pump group to the B port reaches the setting value of the first overflow valve and continues to rise, the high-pressure side oil is selected through the shuttle valve and acts on the pressure cut-off valve to reduce or unload the pressure of the high-pressure oil, and force the pump displacement to reduce, forming a second-level protection.

[0018] The control method sets two control modes, manual and automatic. In the manual control mode: the power supply to the control end of the electric proportional reversing valve is manually adjusted according to the cutting condition of the roller cutting tool to adjust the direction of the roller cutting tool; then in the selected steering mode, the power supply current to the control end of the electric proportional reversing valve is controlled to infinitely adjust the speed of the roller cutting tool.

[0019] Automatic control mode: In constant torque mode, when the roller cutting tool torque exceeds the maximum value of the set range by 10% for 5 minutes, or when the roller cutting tool torque exceeds the maximum value of the set range by 20% for 3 minutes, or when the roller cutting tool torque exceeds the maximum value of the set range by 30% for 1 minute, the geology is considered to be hardened and automatic control adjustment is performed to automatically increase the roller cutting tool speed and reduce the cutting penetration of the roller cutting tool, thereby reducing the roller cutting tool torque.

[0020] When the roller cutting tool torque is 10% lower than the minimum value of the set range for 5 minutes, or when the roller cutting tool torque is 20% lower than the minimum value of the set range for 3 minutes, or when the roller cutting tool torque is 30% lower than the minimum value of the set range for 1 minute, the geology is deemed to be softening and automatic control adjustment is performed; automatic control reduces the roller cutting tool speed, improves the tool cutting penetration and thus increases the roller cutting tool torque; reducing the roller cutting tool speed can reduce the oil supply and thus reduce the heat generated by the oil, thereby improving the efficiency of the closed hydraulic system.

[0021] When the speed of the roller cutting tool reaches the limit value in the constant torque mode, the speed will no longer increase. At this time, when the torque of the roller cutting tool increases and exceeds the constant torque setting value, it will automatically enter the constant power mode.

[0022] The beneficial effects of the present invention are as follows: compared with the existing blind spot processing method, the hydraulic control system of the blind spot processing device proposed by the present invention, firstly, adopts the form of adding cutting tools to the roller, and arranges it in the excavation blind area of ​​the two adjacent circular cutter discs of the front shield and the front partition, which can greatly improve the cross-section excavation rate, thereby reducing the forward resistance of the tunnel boring machine and ensuring the tunnel boring machine's tunnel boring posture. Secondly, a two-way variable pump-two-way quantitative motor closed hydraulic control system is adopted to drive the roller device; it is driven by a hydraulic system, which has the advantages of high power density and high reliability; the closed hydraulic system has the advantages of small leakage, high efficiency and stability, small size, few pipeline connections, large torque and power output range, fast response speed, flexible operation, simple and convenient control, etc. The control method sets two control modes, manual and automatic. In the manual control mode, the direction of the roller can be manually selected and the roller speed can be adjusted. This mode can be used for debugging, getting out of trouble and tunneling. In the automatic control mode, two modes, constant torque control and constant power control, are set; the efficiency of the closed hydraulic system and the tunnel boring efficiency of the tunnel boring machine are improved. The hydraulic control system of the blind spot processing device proposed in the present invention has a simple structure, is easy to maintain, has little disturbance to the soil, has a small amount of over-excavation in the cross section, has a low project cost, and has high construction efficiency. It can reduce the forward resistance of the tunnel boring machine while ensuring the accuracy of the tunnel boring machine's tunneling posture control. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0024] Figure 1 It is a schematic diagram of the hydraulic system principle of the present invention.

[0025] Figure 2 This is the logic principle diagram of the automatic control mode of the present invention.

[0026] Figure 3 This is the cutterhead layout diagram of a non-circular tunnel boring machine. DETAILED DESCRIPTION

[0027] 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Embodiment 1, a hydraulic system of a blind area cutting device of a non-circular tunnel boring machine, includes a drum cutting tool arranged in the excavation blind area of ​​two adjacent circular cutter discs; the drum cutting tool adopts the form of a drum with a cutting tool installed, and is arranged in the excavation blind area of ​​two adjacent circular cutter discs of the front shield and the front partition, which can greatly improve the cross-section excavation rate, thereby reducing the forward resistance of the tunnel boring machine and ensuring the tunneling posture of the tunnel boring machine. The cutting tool is arranged along the drum in a spiral, and when the drum rotates, it can ensure both the high efficiency of cutting the soil and the continuity of the drum load. The drum cutting tool is driven by a closed hydraulic control system. The form of the tool can be changed according to the working conditions, and has the advantage of strong adaptability. For example, a cutting head is used in soft soil formations, and a roller cutter + scraper strip is used in composite formations and hard rock formations. The outer dimensions of the drum are highly adaptable, and can adapt to circular cutter discs of different diameters and different arrangements, and can also be selected according to geological conditions. The drum is driven by a bidirectional quantitative motor arranged on the rear partition of the front shield. The quantitative motor is small in size and easy to install. It only needs oil return and oil drain pipelines, and does not require any power supply and control. The quantitative motor has a simple structure, is not easy to damage, and is easy to replace and maintain. It is particularly suitable for occasions where there are many equipment in the shield and the space is small. The pick cutting tool is arranged and installed on the drum in a spiral form and can be used in soft soil formations; the roller cutter is installed on the drum and can be used in composite formations and hard rock formations. The cutting tools are arranged in a spiral form. During the rotary cutting process of the drum, the continuity of the tool cutting in and out can be maintained, and a certain number of tools can always be kept in the cutting state, that is, the continuity of the drum load can be maintained, preventing load step changes from causing damage to the drum and tool, as well as vibration and noise; such as Figure 3 shown.

[0029] The closed hydraulic control system includes a pump group 1, and the A port and the B port of the pump group 1 are connected to the bidirectional quantitative motor group 2 through pipelines respectively; the bidirectional quantitative motor is provided with rotational power, thereby driving the roller cutting tool to rotate, which is used for blind area excavation. A return oil control valve group 3 is arranged between the A port and the B port of the bidirectional quantitative motor group 2; part of the hydraulic oil on the return oil side can flow back to the oil tank through the hot oil return oil control valve group 3, which is used to lead part of the hot oil on the return oil side out of the closed hydraulic system. The pump group 1 includes a bidirectional variable pump 11 and a supplementary oil pump 12; the bidirectional variable pump refers to a method of changing the displacement of the pump by changing the variable mechanism (such as the tilt direction and angle of the axial piston pump swash plate) or the compression ratio when the rotation direction of the prime mover remains unchanged. The first part of the supplementary oil of the supplementary oil pump 12 adjusts the output direction and displacement of the bidirectional variable pump 11 through the displacement adjustment device for control. The second part of the supplementary oil of the supplementary oil pump 12 supplements the pump group through the supplementary oil valve group to supplement the return oil side. The roller device is driven by a closed hydraulic control system of a bidirectional variable pump and a bidirectional fixed motor; it is driven by a hydraulic system with the advantages of high power density and high reliability; the closed hydraulic system has the advantages of small leakage, high efficiency and stability, small size, few pipeline connections, large torque and power output range, fast response speed, flexible operation, simple and convenient control, etc.

[0030] Specifically, the replenishing pump 12 sucks oil from the S port of the pump group 1, and the S port is connected to the oil tank. The oil flowing out of the replenishing pump 12 enters the first filter 13 through the Fe port of the pump group 1. The first filter is used to filter the replenishing oil, and then enters the replenishing oil pipeline in the pump group 1 through the Fa port of the pump group 1. The part of the oil in the replenishing oil pipeline that enters the displacement regulating device forms the first part of replenishing oil, and the part of the oil in the replenishing oil pipeline that enters the replenishing oil valve group forms the second part of replenishing oil. The first part of the replenishing oil can be used as control oil, and the displacement regulating device is controlled to control the output direction of the two-way variable pump and adjust the displacement, thereby realizing motor steering control and speed regulation. The second part of the replenishing oil enters the return oil pipeline of the pump group as replenishing oil to replenish the pump group.

[0031] The oil replenishment pump 12 can adopt a fixed-displacement pump, and a fixed-displacement pump connected in series with a bidirectional variable pump is used to replenish oil in a closed circuit. The oil replenishment pump is responsible for compensating for hydraulic oil leakage in the circuit on the one hand, and for the hot oil displacement compensation as mentioned above on the other hand. The oil replenishment pump supplies oil to the return oil side of the bidirectional variable pump, has a small load pressure, is directly connected in series with the bidirectional variable pump and driven by the same motor, and has the advantage of high integration.

[0032] On the whole, during the operation of the system, the hydraulic oil is output from the A port of the pump group at high pressure (the A port is the high pressure side, also called the oil supply side), and then enters the A port of the hydraulic motor to drive the motor to rotate. After the work is completed, the hydraulic oil is output from the B port of the motor at low pressure (the B port is the low pressure side, also called the oil return side), and then enters the B port of the pump group to form a closed cycle. Alternatively, the hydraulic oil is output from the B port of the pump group at high pressure (the B port is the high pressure side, also called the oil supply side), and then enters the B port of the hydraulic motor to drive the motor to rotate. After the work is completed, the hydraulic oil is output from the A port of the motor at low pressure (the A port is the low pressure side, also called the oil return side), and then enters the A port of the pump group to form a closed cycle. A closed cycle is a closed hydraulic system, which refers to a hydraulic system in which the oil suction port of the hydraulic pump is connected to the oil discharge port of the hydraulic motor, and only a small amount of oil replenishment is required in the system.

[0033] like Figure 1 As shown, Example 2 is a hydraulic system for a blind area cutting device of a non-circular tunnel boring machine. Based on Example 1, this example is preferred. The displacement regulating device includes an electric proportional reversing valve 5 and an adjusting oil cylinder 6 that controls the swash plate of a two-way variable pump 11; the first part of the supplementary oil controls the telescopic direction and telescopic amount of the adjusting oil cylinder 6 through the electric proportional reversing valve 5; the adjusting oil cylinder 6 adjusts the inclination direction and inclination angle of the swash plate of the two-way variable pump 11 to achieve the regulation of the output direction and displacement of the two-way variable pump, thereby realizing the motor steering control and speed regulation. The two-way variable pump 11 is connected to a motor 4, which provides power for the two-way variable pump. By applying current to the electromagnets at both ends of the electric proportional reversing valve 5, the valve core is driven to move to change the working state and then the regulating oil cylinder 6 is driven to move to select the output direction of the pump 11 and adjust the displacement, thereby realizing the motor steering control and speed regulation. For example, the electric proportional reversing valve 5 is given a current to the left electromagnet, driving the valve core to move rightward, so that the control oil enters the left chamber of the displacement adjustment device 6 to drive the piston to move rightward. In this state, the output motor of port A rotates forward, and the output motor of port B rotates reversely. The displacement can be adjusted by changing the size of the electromagnet current, that is, the speed of the motor can be adjusted. When the electric proportional reversing valve 5 does not perform any control, the displacement of the pump is zero, and the two-way variable pump can be started without load.

[0034] The oil replenishment valve group in this embodiment includes a first oil replenishment valve and a second oil replenishment valve arranged in parallel. When the A port of the pump group 1 outputs high-pressure oil, the second part of the replenishment oil is replenished through the first oil replenishment valve and the return oil pipeline entering the B port; when the B port of the pump group 1 outputs high-pressure oil, the second part of the replenishment oil is replenished through the second oil replenishment valve and the return oil pipeline entering the A port; the oil replenishment on the return oil side under two working conditions is realized. The oil circuit of the second part of the replenishment oil is connected to a third overflow valve 72 and a pressure sensor 14. The third overflow valve 72 is connected to the oil circuit as an oil unloading device, and the third overflow valve 72 sets the replenishment pressure of the bidirectional variable pump.

[0035] Specifically, the first oil replenishment valve includes a first check valve 8 and a first overflow valve 7 arranged in parallel, and the first overflow valve is connected to the oil circuit leading to the B port of the pump group; that is, the first overflow valve 7 is used for overflow of the pipeline when the B port is used as a high-pressure port, and the first check valve 8 and the B port are used as oil replenishment of the oil circuit of the return port. The second oil replenishment valve includes a second check valve 81 and a second overflow valve 71 arranged in parallel; the second overflow valve 71 is connected to the oil circuit leading to the A port of the pump group 1, and is used for overflow of the pipeline when the A port is used as a high-pressure oil outlet; the second check valve 81 and the A port are used as oil replenishment of the oil circuit when the return port is used.

[0036] In this embodiment, a discharge branch I100 is provided between the pipeline leading to port A and the pipeline leading to port B of the pump group 1, and a shuttle valve 9 is provided on the discharge branch. The shuttle valve 9 is connected to a pressure cut-off valve 10, and the pressure cut-off valve 10 is connected to the electric proportional reversing valve 5 of the displacement regulating device through the discharge branch II200; it is used for discharge. When the outlet pressure of the two-way variable pump 11 reaches the set value of the relief valve 7 / 71 and continues to rise, in order to prevent damage to the pump, the pump high-pressure side oil is selected through the shuttle valve 9 and acts on the pressure cut-off valve 10, so that the control oil pressure is reduced or discharged, and the pump displacement is forced to be reduced.

[0037] The bidirectional quantitative motor group 2 described in this embodiment includes a first bidirectional quantitative motor 21 and a second bidirectional quantitative motor 22 arranged in parallel. The bidirectional quantitative motor refers to a hydraulic motor that can take in oil in both directions but has a constant theoretical output displacement. The first bidirectional quantitative motor 21 and the second bidirectional quantitative motor 22 provide rotational power for the roller cutting tool; the first bidirectional quantitative motor 21 and the second bidirectional quantitative motor 22 are fixed displacements, and have only two oil circuits directly connected to the A / B ports of this group and one oil unloading oil circuit, forming a closed hydraulic system. The bidirectional quantitative motor is connected to the bidirectional variable pump in a closed connection drive. The use of a closed connection can reduce the loss of hydraulic oil, improve the efficiency and stability of the system, and can provide greater force and power output with relatively small size and weight. It also has the advantages of fast response, flexible operation, and simple and convenient program control.

[0038] The oil return control valve group 3 in this embodiment includes a hydraulically controlled reversing valve 31 and a fourth overflow valve 33 arranged in series, and a throttle hole 32 is provided on the pipeline between the hydraulically controlled reversing valve 31 and the fourth overflow valve 33. By setting the pressure of the third overflow valve 72 and forming a pressure difference with the fourth overflow valve 33, and according to the pressure difference flow formula of the throttle hole 32, the oil change flow in the closed hydraulic system is adjusted. A hot oil return valve is used to guide part of the hydraulic oil on the motor return oil side in the closed loop to the oil tank, and the guided hydraulic oil is filtered and cooled in the oil tank. The filtered and cooled hydraulic oil is then supplemented by the oil supplement pump to the suction side of the two-way variable pump, which can ensure the purity of the hydraulic oil in the closed system, improve the service life of the system equipment and components, and prevent the system efficiency and stability from being reduced due to excessive temperature of the hydraulic oil.

[0039] Example 3, a method for controlling the hydraulic system of a blind spot cutting device of a non-circular tunnel boring machine as described in Example 2: the pump group 1 is started by an electric motor, the first part of the make-up oil of the oil make-up pump 12 is drawn out and used as control oil, and the control oil enters the electric proportional reversing valve 5 and the regulating cylinder 6 to select the inlet and outlet oil ports and control the displacement of the bidirectional variable pump 11.

[0040] In the first case, when port A of pump group 1 is the high-pressure oil outlet and port B is the low-pressure oil inlet, the high-pressure oil in the two-way variable pump 11 enters port A of the two-way quantitative motor group 2 and the hydraulic control reversing valve 31 through port A. At this time, the two-way quantitative motor group 2 drives the roller cutting tool to rotate forward, and the valve core of the hydraulic control reversing valve 31 moves to connect the throttling hole 32 with the fourth overflow valve 33; the oil after entering the two-way quantitative motor group 2 flows out through port B of the two-way quantitative motor group 2; a part of the oil flowing out through port B of the two-way quantitative motor group 2 flows back to the pump group through port B of the pump group 1 to form a closed hydraulic system. Part of it flows back to the oil tank through the hydraulically controlled reversing valve 31, the throttle hole 32 and the fourth overflow valve 33, and part of the hot oil on the return oil side is led out of the closed hydraulic system; at the same time, part of the second part of the replenishing oil of the oil replenishing pump 12 is combined with the oil flowing back from the B port of the pump group 1 through the first one-way valve 8 of the first oil replenishing valve for replenishing oil; part of the second part of the replenishing oil of the oil replenishing pump 12 overflows through the third overflow valve 72, and by setting the pressure of the third overflow valve 72 and forming a pressure difference △P with the fourth overflow valve 33, and according to the pressure difference flow formula of the throttle hole 32, the oil change flow in the closed hydraulic system is adjusted.

[0041] The differential pressure flow formula of the throttle hole is: Among them, Q represents the flow rate; C d is the flow coefficient; A is the cross-sectional area of ​​the throttle hole; △P is the pressure difference before and after the throttle hole, and ρ is the oil density.

[0042] When the pressure of the high-pressure oil flowing from the pump group 1 to the A port exceeds the setting value of the second relief valve 71, the overflow is formed through the second relief valve 71 to form the first-level protection; specifically, the high-pressure oil flowing to the A port flows to the first check valve 8 through the second relief valve 71, and merges with the oil flowing back from the B port of the pump group 1 to overflow. When the pressure of the high-pressure oil flowing from the pump group 1 to the A port reaches the setting value of the second relief valve 71 and continues to rise, the high-pressure side oil is selected through the shuttle valve 9 and acts on the pressure cut-off valve 10, so that the pressure of the high-pressure oil is reduced or unloaded, and the pump displacement is forced to be reduced, forming the second-level protection.

[0043] In the second case, when the B port of the pump group 1 is the high-pressure oil outlet and the A port is the low-pressure oil inlet, the high-pressure oil in the two-way variable pump 11 enters the B port of the two-way quantitative motor group 2 and the hydraulic control reversing valve 31 through the B port. At this time, the two-way quantitative motor group 2 drives the roller cutting tool to rotate in the opposite direction, and the valve core of the hydraulic control reversing valve 31 moves to connect the throttling hole 32 with the fourth overflow valve 33; the oil after entering the two-way quantitative motor group 2 flows out through the A port of the two-way quantitative motor group 2; a part of the oil flowing out through the A port of the two-way quantitative motor group 2 flows back to the pump group through the A port of the pump group 1 to form a closed hydraulic system, and a part of the oil flows back to the pump group through the A port of the pump group 1 to form a closed hydraulic system. It flows back to the oil tank through the hydraulically controlled reversing valve 31, the throttle hole 32 and the fourth overflow valve 33, and part of the hot oil on the return oil side is led out of the closed hydraulic system; at the same time, a part of the second part of the replenishing oil of the oil replenishing pump 12 is combined with the oil flowing back from the A port of the pump group 1 through the second one-way valve 81 of the second oil replenishing valve for replenishing oil; a part of the second part of the replenishing oil of the oil replenishing pump 12 overflows through the third overflow valve 72, and by setting the pressure of the third overflow valve 72 and forming a pressure difference △P with the fourth overflow valve 33, and according to the pressure difference flow formula of the throttle hole 32, the oil change flow in the closed hydraulic system is adjusted.

[0044] The pressure differential flow formula of the throttle hole 32 is: The pressure differential flow formula of the throttle hole is: Q = C d ×A× Among them, Q represents the flow rate; C d is the flow coefficient; A is the cross-sectional area of ​​the throttle hole; △P is the pressure difference before and after the throttle hole, and ρ is the oil density.

[0045] When the pressure of the high-pressure oil flowing from the pump group 1 to the B port exceeds the setting value of the first relief valve 7, the first relief valve 7 overflows to form a first-level protection. Specifically, part of the high-pressure oil flowing to the B port flows to the first relief valve and flows to the second check valve 81 through the first relief valve, and merges with the oil flowing back from the A port of the pump group 1 to overflow. When the pressure of the high-pressure oil flowing from the pump group 1 to the B port reaches the setting value of the first relief valve 7 and continues to increase, the high-pressure side oil is selected through the shuttle valve 9 and acts on the pressure cut-off valve 10, so that the pressure of the high-pressure oil is reduced or unloaded, and the pump displacement is forced to be reduced; forming a second-level protection.

[0046] The first-level protection and the second-level protection constitute the system safety protection; the oil replenishment pressure is monitored, and the oil replenishment is also used as the pump displacement control oil. Low oil replenishment pressure will cause the pump displacement to lose control, and a minimum pressure limit must be set. When the oil replenishment pressure is lower than the minimum pressure limit, the system automatically shuts down and the non-circular tunnel boring machine stops tunneling; in addition, the oil replenishment pressure cannot be too high, which will reduce the motor torque output range and reduce the system efficiency. A maximum pressure limit must be set. When the oil replenishment pressure is higher than the maximum pressure limit, the control end alarm will be issued but the machine will not be shut down, and the problem can be promptly investigated.

[0047] The control method sets two control modes, manual and automatic. In the manual control mode, the power supply of the control end of the electric proportional reversing valve 5 is manually adjusted according to the cutting condition of the drum cutting tool to adjust the direction of the drum cutting tool; then, in the selected steering mode, the power supply current of the control end of the electric proportional reversing valve 5 is controlled to infinitely adjust the speed of the drum cutting tool. This mode can be used for debugging, getting out of trouble and excavation.

[0048] Automatic control mode: The drum cutting tool is different from the circular cutter disc tool. The circular cutter disc tool is always in the cutting (stress) state during the working process, while the drum cutting tool is in a high-frequency periodic load change with a cycle of idling-cutting-cutting-cutting-idling, which causes the drum cutting tool to suffer fatigue-based damage. In order to increase the service life of the cutting tool and prevent the tool from experiencing large force changes during the cutting process as much as possible, the change in the number of cutting tools involved in the cutting process is analyzed through cross-section, and the optimal tool cutting efficiency and cutting force range are selected to determine the optimal torque range of the drum. The torque control of the drum is reflected in the hydraulic system as the inlet and outlet oil pressure difference of the bidirectional motor. The displacement of the motor is fixed, so the output torque of the motor changes linearly with the inlet and return oil pressure difference. The inlet oil pressure uses the monitored pump head pressure, and the return oil pressure uses the monitored replenishment oil pressure.

[0049] During the tunneling process of the tunnel boring machine, when the tunneling speed does not change; in the constant torque mode, when the drum cutting tool torque exceeds the maximum value of the set range by 10% for 5 minutes, or when the drum cutting tool torque exceeds the maximum value of the set range by 20% for 3 minutes, or when the drum cutting tool torque exceeds the maximum value of the set range by 30% for 1 minute, the geology is considered to be hardened and automatic control adjustment is performed; automatic control increases the speed of the drum cutting tool, reduces the cutting penetration of the drum cutting tool, and thus reduces the torque of the drum cutting tool.

[0050] When the roller cutting tool torque is 10% lower than the minimum value of the set range for 5 minutes, or when the roller torque is 20% lower than the minimum value of the set range for 3 minutes, or when the roller torque is 30% lower than the minimum value of the set range for 1 minute, the geology is deemed to be softening and automatic control adjustment is performed; automatic control reduces the roller cutting tool speed, improves the tool cutting penetration and thus increases the roller cutting tool torque; reducing the roller cutting tool speed can reduce the oil supply and thus reduce the heat generated by the oil, thereby improving the efficiency of the closed hydraulic system.

[0051] In constant torque mode, when the change of the local formation causes the torque of the drum to increase, the automatic control will increase the speed of the drum to reduce the torque. On the one hand, the maximum speed of the motor is limited by the displacement of the pump. On the other hand, the inertia of the drum device is large. In complex formations, such as soft soil formations with sparse pebbles, the cutter suddenly hits foreign objects during the high-speed operation of the drum, which can easily cause the cutter to break. To ensure the service life of the cutter, the speed of the drum device in constant torque mode should not be too high. When the drum speed reaches the limit value in constant torque mode, the speed will no longer increase. At this time, when the drum torque increases by more than the constant torque setting value, it will automatically switch to constant power mode. The critical point of the two modes is reflected in the hydraulic system as the oil supply pressure and displacement of the pump. The real-time power is calculated by monitoring the pump outlet pressure and the output displacement control current. In order to prevent the monitoring data value from jumping around the above critical point, causing the control system to malfunction and cause system instability, a transition mode is set between the constant torque mode and the constant power mode. When the motor speed reaches the maximum limit value, the motor torque is allowed to exceed a certain value of the constant torque. When it exceeds this value, it enters the constant power mode; such as Figure 2 shown.

[0052] The hydraulic system has only two feedback signals (variable pump oil supply side pressure, replenishment pump pressure) and two input control signals (variable pump positive displacement adjustment, reverse displacement adjustment). The system is manually and automatically controlled through the electrical control program. Manual control realizes the forward and reverse rotation and speed control of the drum, and automatic control matches the excavation conditions of non-circular shield machines. Automatic control can be divided into constant torque control and constant power control coordinated with the oil supply side pressure feedback signal.

[0053] Example 4: It should be noted that for the blind spot processing device, a floating milling head device can be used. Compared with the drum device, the rotating axis of the milling head coincides with the rotating axis of the motor, and the transmission structure is simple, but the excavation section of the milling head is not formed in one step. A ball joint must be set on the shield partition so that the milling head can rotate while turning. For the hydraulic drive system, an open hydraulic system formed by a one-way variable pump, a proportional multi-way valve, a two-way directional motor, etc. can be used; the open hydraulic system has a simple structure, and since the hydraulic oil returns to the oil tank after work, it can better dissipate heat and filter; the proportional multi-way valve can realize various complex controls in the hydraulic system, with flexible control and high reliability, and the valve core and valve body have simple manufacturing processes, low cost, and are easy to disassemble, clean and maintain.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hydraulic system for a blind area cutting device of a non-circular tunnel boring machine, characterized in that: The invention comprises a roller cutting tool arranged in an excavation blind area of ​​two adjacent circular cutter discs, wherein the roller cutting tool is driven by a closed hydraulic control system; the closed hydraulic control system comprises a pump group (1), wherein the A port and the B port of the pump group (1) are respectively connected to a bidirectional quantitative motor group (2), and an oil return control valve group (3) is arranged between the A port and the B port of the bidirectional quantitative motor group (2); the pump group (1) comprises a bidirectional variable pump (11) and an oil replenishment pump (12); the first part of the replenishment oil of the oil replenishment pump (12) adjusts the output direction and displacement of the bidirectional variable pump (11) through a displacement adjustment device; and the second part of the replenishment oil of the oil replenishment pump (12) replenishes the pump group through an oil replenishment valve group.

2. The hydraulic system of the blind area cutting device of a non-circular tunnel boring machine according to claim 1 is characterized in that: The oil replenishment pump (12) sucks oil from the S port of the pump unit (1). The oil flowing out of the oil replenishment pump (12) enters the first filter (13) through the Fe port of the pump unit (1), and then enters the oil replenishment pipeline in the pump unit (1) through the Fa port of the pump unit (1). The oil in the oil replenishment pipeline enters the displacement adjustment device to form the first part of replenishment oil, and the oil in the oil replenishment pipeline enters the oil replenishment valve group to form the second part of replenishment oil.

3. The hydraulic system of the blind area cutting device of a non-circular tunnel boring machine according to claim 1 is characterized in that: The displacement regulating device comprises an electric proportional reversing valve (5) and an regulating oil cylinder (6) for controlling a swash plate of a bidirectional variable pump (11); the first part of the supplementary oil controls the extension direction and extension amount of the regulating oil cylinder (6) via the electric proportional reversing valve (5); and the bidirectional variable pump (11) is connected to a motor (4).

4. The hydraulic system of the blind area cutting device of a non-circular tunnel boring machine according to claim 1 or 3, characterized in that: The oil replenishment valve group comprises a first oil replenishment valve and a second oil replenishment valve arranged in parallel. When the A port of the pump group (1) outputs high-pressure oil, the second part of the replenishment oil is replenished through the first oil replenishment valve and the oil return pipeline entering the B port; when the B port of the pump group (1) outputs high-pressure oil, the second part of the replenishment oil is replenished through the second oil replenishment valve and the oil return pipeline entering the A port.

5. The hydraulic system of the blind area cutting device of a non-circular tunnel boring machine according to claim 4, characterized in that: The first oil supply valve comprises a first non-return valve (8) and a first overflow valve (7) which are arranged in parallel, and the first overflow valve (7) is connected to the oil circuit leading to the B port of the pump group (1); the second oil supply valve comprises a second non-return valve (81) and a second overflow valve (71) which are arranged in parallel; the second overflow valve (71) is connected to the oil circuit leading to the A port of the pump group (1).

6. The hydraulic system of the blind area cutting device of the non-circular tunnel boring machine according to claim 5, characterized in that: A third overflow valve (72) and a pressure sensor (14) are connected to the oil circuit of the second portion of supplementary oil.

7. The hydraulic system of the blind area cutting device of a non-circular tunnel boring machine according to claim 6, characterized in that: A discharge branch I (100) is provided between the pipeline leading to port A and the pipeline leading to port B of the pump group (1), a shuttle valve (9) is provided on the discharge branch, the shuttle valve (9) is connected to a pressure cut-off valve (10), and the pressure cut-off valve (10) is connected to the electric proportional reversing valve (5) of the displacement regulating device through the discharge branch II (200).

8. The hydraulic system of the blind area cutting device of a non-circular tunnel boring machine according to claim 1 or 7, characterized in that: The bidirectional quantitative motor group (2) comprises a first bidirectional quantitative motor (21) and a second bidirectional quantitative motor (22) which are arranged in parallel, and the first bidirectional quantitative motor (21) and the second bidirectional quantitative motor (22) provide rotational power for the roller cutting tool; The oil return control valve group (3) comprises a hydraulically controlled reversing valve (31) and a fourth overflow valve (33) which are arranged in series, and a throttling hole (32) is provided on the pipeline between the hydraulically controlled reversing valve (31) and the fourth overflow valve (33).

9. A method for controlling a hydraulic system of a blind area cutting device of a non-circular tunnel boring machine as claimed in claim 8, characterized in that: The pump group (1) is started, and the first part of the supplementary oil of the supplementary oil pump (12) is led out to be used as control oil. The control oil enters the electric proportional reversing valve (5) and the regulating cylinder (6), and performs oil inlet and outlet selection and displacement control on the bidirectional variable pump (11); When the A port of the pump group (1) is the high-pressure oil outlet and the B port is the low-pressure oil inlet, the high-pressure oil in the two-way variable pump (11) enters the A port of the two-way quantitative motor group (2) and the hydraulic control reversing valve (31) through the A port. At this time, the two-way quantitative motor group (2) drives the roller cutting tool to rotate in the forward direction, and the valve core of the hydraulic control reversing valve (31) moves to connect the throttling hole (32) with the fourth overflow valve (33); the oil after entering the two-way quantitative motor group (2) flows out through the B port of the two-way quantitative motor group (2); part of the oil flowing out through the B port of the two-way quantitative motor group (2) flows back to the pump group through the B port of the pump group (1) to form a closed hydraulic system, and part of it flows back to the oil tank through the hydraulic control reversing valve (31), the throttling hole (32) and the fourth overflow valve (33), so that part of the hot oil on the return oil side is led out of the closed hydraulic system; at the same time, part of the second part of the replenishment oil of the replenishment pump (12) is replenished. The oil flowing back through the first check valve (8) of the first oil replenishment valve and the oil flowing back from the B port of the pump group (1) are combined to replenish the oil; a part of the second part of the replenishment oil of the replenishment pump (12) overflows through the third overflow valve (72), and by setting the pressure of the third overflow valve (72), a pressure difference △P is formed with the fourth overflow valve (33), and the oil change flow in the closed hydraulic system is adjusted according to the pressure difference flow formula of the throttle hole (32); when the pressure of the high-pressure oil flowing from the pump group (1) to the A port exceeds the set value of the second overflow valve (71), the oil overflows through the second overflow valve (71) to form a first-level protection; when the pressure of the high-pressure oil flowing from the pump group (1) to the A port reaches the set value of the second overflow valve (71) and continues to increase, the high-pressure side oil is selected through the shuttle valve (9) and acts on the pressure cut-off valve (10), so that the pressure of the high-pressure oil is reduced or unloaded, and the pump displacement is forced to be reduced, forming a second-level protection; When the B port of the pump group (1) is the high-pressure oil outlet and the A port is the low-pressure oil inlet, the high-pressure oil in the bidirectional variable pump (11) enters the B port of the bidirectional quantitative motor group (2) and the hydraulically controlled reversing valve (31) through the B port. At this time, the bidirectional quantitative motor group (2) drives the roller cutting tool to rotate in the opposite direction, and the valve core of the hydraulically controlled reversing valve (31) moves to connect the throttling hole (32) with the fourth overflow valve (33); the oil after entering the bidirectional quantitative motor group (2) flows out through the A port of the bidirectional quantitative motor group (2); part of the oil flowing out through the A port of the bidirectional quantitative motor group (2) flows back to the pump group through the A port of the pump group (1) to form a closed hydraulic system, and part of the oil flows back to the oil tank through the hydraulically controlled reversing valve (31), the throttling hole (32) and the fourth overflow valve (33), thereby leading part of the hot oil on the return oil side out of the closed hydraulic system; at the same time, part of the second part of the replenishing oil of the replenishing pump (12) is replenished. A part of the oil flowing back through the second check valve (81) of the second oil replenishment valve is combined with the oil flowing back from the port A of the pump group (1) to replenish the oil; a part of the second part of the replenishment oil of the replenishment pump (12) overflows through the third overflow valve (72), and by setting the pressure of the third overflow valve (72), a pressure difference △P is formed with the fourth overflow valve (33), and the oil change flow in the closed hydraulic system is adjusted according to the pressure difference flow formula of the throttle hole (32); when the pressure of the high-pressure oil flowing from the pump group (1) to the port B exceeds the set value of the first overflow valve (7), overflow is formed through the first overflow valve (7) to form a first-level protection; when the pressure of the high-pressure oil flowing from the pump group (1) to the port B reaches the set value of the first overflow valve (7) and continues to increase, the high-pressure side oil is selected through the shuttle valve (9) and acts on the pressure cut-off valve (10), so that the pressure of the high-pressure oil is reduced or unloaded, and the pump displacement is forced to be reduced, thereby forming a second-level protection.

10. The control method of the hydraulic system of the blind area cutting device of the non-circular tunnel boring machine according to claim 9, characterized in that: This control method sets two control modes: manual and automatic; In manual control mode: the power supply to the control end of the electric proportional reversing valve (5) is manually adjusted according to the cutting condition of the roller cutting tool to adjust the direction of the roller cutting tool; then, in the selected direction mode, the power supply current to the control end of the electric proportional reversing valve (5) is controlled to infinitely adjust the speed of the roller cutting tool; Automatic control mode: In constant torque mode, when the roller cutting tool torque exceeds the maximum value of the setting range by 10% for 5 minutes, or when the roller cutting tool torque exceeds the maximum value of the setting range by 20% for 3 minutes, or when the roller cutting tool torque exceeds the maximum value of the setting range by 30% for 1 minute, the ground is considered to be hardened and automatic control adjustment is performed; automatic control increases the roller cutting tool speed, reduces the cutting penetration of the roller cutting tool, and thus reduces the roller cutting tool torque; When the roller cutting tool torque is lower than the minimum value of the setting range by 10% for 5 minutes, or when the roller cutting tool torque is lower than the minimum value of the setting range by 20% for 3 minutes, or when the roller cutting tool torque is lower than the minimum value of the setting range by 30% for 1 minute, the geology is considered to be soft and automatic control adjustment is performed; automatic control reduces the roller cutting tool speed, improves the tool cutting penetration and thus increases the roller cutting tool torque; reducing the roller cutting tool speed can reduce the oil supply and thus reduce the heat generated by the oil, thereby improving the efficiency of the closed hydraulic system; when the roller cutting tool speed reaches the limit value in the constant torque mode, the speed no longer increases. At this time, when the roller cutting tool torque increases by more than the constant torque setting value, it automatically switches to the constant power mode.

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