An automatic control system for the mixing device of an extra-large diameter earth pressure balance shield machine

Abstract

The present invention relates to the technical field of automatic mixing control of soil bin of earth pressure balance shield machine, and specifically to an automatic control system of a mixing device of an ultra-large diameter earth pressure balance shield machine, comprising a power system and a control execution system, wherein the power system comprises a pump, an electromagnetic proportional reversing valve, a hydraulically controlled reversing valve, a first relief valve, a proportional relief valve, a one-way valve, a ball valve and a filter; the control execution system comprises a pressure compensation valve, a proportional multi-way valve, a first pressure reducing valve and a second pressure reducing valve, and the outlet oil circuit of the power system is respectively connected to the oil inlet of the pressure compensation valve, the first pressure reducing valve and the second pressure reducing valve. The automatic mixing device realizes the control of different speeds according to different geological conditions, and performs dynamic adjustment according to the real-time slag discharge conditions. The automatic control system can realize forward and reverse stepless speed regulation, adjust the pump displacement according to the actual speed, and automatically adjust the pump pressure according to the excavation speed and soil bin pressure to reduce energy consumption.

Description

Technical Field

[0001] The invention relates to the technical field of automatic mixing control of soil bin of an earth pressure balance shield machine, and in particular to an automatic control system of a mixing device of an earth pressure balance shield machine with a super large diameter. Background Art

[0002] At present, conventional earth pressure balance shield machines use fixed passive stirring rods to stir the soil bin during urban subway construction. The passive stirring rods can only perform passive stirring through the rotation of the cutter head and the falling of the slag. The stirring effect is not ideal, which can easily cause the slag to accumulate in the soil bin and unsmooth excavation. In addition, the slag often lacks fluidity due to uneven stirring of the traditional stirring rods in the soil bin, forming mud cakes, increasing the torque of the cutter head, and when the mud cakes are serious, the equipment cannot be excavated normally. In large-diameter shield machines, the fluidity of the slag is worse due to the increase in the soil bin. Using only passive stirring rods often cannot meet the requirements of stirring the slag to increase its fluidity. If the stirring device is not replaced, the shield machine cannot perform normal excavation at all. Summary of the invention

[0003] In order to overcome the defects existing in the prior art, the present invention provides an automatic control system for a mixing device of an ultra-large diameter earth pressure balance shield machine. The system realizes more sufficient soil bin mixing by controlling the rotation of the mixing rod, and can realize individual control of different mixing rods, so that the slag can flow irregularly. The automatic mixing device realizes control of different rotation speeds according to different geological conditions, and makes dynamic adjustments according to the real-time slag discharge conditions. The automatic control system can realize stepless speed regulation in forward and reverse rotation, adjust the displacement of the pump according to the actual speed, and automatically adjust the pressure of the pump according to the excavation speed and soil bin pressure to reduce energy consumption.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] The invention provides an automatic control system for a mixing device of an ultra-large diameter earth pressure balance shield machine, comprising a power system and a control execution system, wherein the power system comprises a pump, an electromagnetic proportional reversing valve, a hydraulically controlled reversing valve, a first relief valve, a proportional relief valve, a check valve, a ball valve and a filter, wherein a control oil is led out from the outlet of the pump to connect the electromagnetic proportional reversing valve, the proportional relief valve and the hydraulically controlled reversing valve, the oil outlet of the electromagnetic proportional reversing valve is connected to the oil inlet of the hydraulically controlled reversing valve, the oil inlet of the proportional relief valve is simultaneously connected to the other side of the hydraulically controlled reversing valve, the outlet of the pump is connected in series with the ball valve, the check valve and the filter in sequence, and then connected to the control execution system; the control execution system comprises a pressure compensation valve, a proportional multi-way valve, a first pressure reducing valve and a second pressure reducing valve, the outlet oil circuit of the power system is respectively connected to the oil inlets of the pressure compensation valve, the first pressure reducing valve and the second pressure reducing valve, the oil outlet of the pressure compensation valve is connected to the proportional multi-way valve, the oil outlet of the first pressure reducing valve is connected to the control oil circuit of the proportional multi-way valve, and the oil outlet of the second pressure reducing valve is connected to a motor.

[0006] Furthermore, a first pressure sensor and a pressure gauge are provided on the outlet oil circuit of the pump.

[0007] Furthermore, a second pressure sensor is connected to the inlet oil circuit of the motor via a shuttle valve.

[0008] Furthermore, a balancing valve is provided on the inlet oil circuit of the motor.

[0009] Furthermore, a second relief valve is connected in parallel to the inlet oil circuit of the first pressure reducing valve.

[0010] Furthermore, the number of the control execution systems is three and they are connected in parallel with each other.

[0011] Compared with the prior art, the present invention has the following positive and beneficial effects:

[0012] The present invention provides an automatic control system for a super-large diameter earth pressure balance shield machine stirring device, which is a variable pump throttling speed control circuit, which can adapt to the working conditions of large torque and high speed, and can realize functions such as stepless speed regulation, overload protection, and bidirectional rotation, with stable operation performance and good use effect. By driving the corresponding stirring rods to rotate in different directions by multiple motors, the soil bin is fully stirred, which can effectively reduce the mud cake condition of the soil bin, increase the fluidity of the soil bin slag, and improve the improvement effect of slag improvers such as foam, thereby improving the tunneling efficiency of the shield machine and reducing construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The present invention is a structural schematic diagram of an automatic control system for a mixing device of an ultra-large diameter earth pressure balance shield machine.

[0014] The meanings of the serial numbers in the figure are: 1. Pump, 2. Solenoid proportional reversing valve, 3. First relief valve, 4. Proportional relief valve, 5. Pressure gauge, 6. First pressure sensor, 7. Ball valve, 8. Check valve, 9. Filter, 10. Proportional multi-way valve, 11. Pressure compensation valve, 12. Second relief valve, 13. First pressure reducing valve, 14. Shuttle valve, 15. Motor, 16. Second pressure reducing valve, 17. Balancing valve, 18. Second pressure sensor, 19. Hydraulic control reversing valve. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0016] Embodiment 1, as Figure 1 As shown, an automatic control system for a mixing device of an ultra-large diameter earth pressure balance shield machine includes a power system and a control execution system. The power system includes a pump 1, an electromagnetic proportional reversing valve 2, a hydraulically controlled reversing valve 19, a first relief valve 3, a proportional relief valve 4, a one-way valve 8, a ball valve 7 and a filter 9. The outlet of the pump 1 leads out a control oil connection to the electromagnetic proportional reversing valve 2, the proportional relief valve 4 and the hydraulically controlled reversing valve 19. The oil outlet of the electromagnetic proportional reversing valve 2 is connected to the oil inlet of the hydraulically controlled reversing valve 19. The oil inlet of the proportional relief valve 4 is also connected to the other oil inlet of the hydraulically controlled reversing valve 19. On the other hand, the outlet of the pump 1 is connected in series with a ball valve 7, a one-way valve 8 and a filter 9 in sequence and then connected to a control execution system; the control execution system includes a pressure compensating valve 11, a proportional multi-way valve 10, a first pressure reducing valve 13 and a second pressure reducing valve 16, and the outlet oil circuit of the power system is respectively connected to the oil inlets of the pressure compensating valve 11, the first pressure reducing valve 13 and the second pressure reducing valve 16, the oil outlet of the pressure compensating valve 11 is connected to the proportional multi-way valve 10, the oil outlet of the first pressure reducing valve 13 is connected to the control oil circuit of the proportional multi-way valve 10, and the oil outlet of the second pressure reducing valve 16 is connected to the motor 15.

[0017] The first relief valve 3 is connected to the oil outlet of the pump 1 through a three-way connection, and is used for safety protection when the proportional relief valve 4 fails.

[0018] A first pressure sensor 6 and a pressure gauge 5 are provided on the outlet oil circuit of the pump 1 to monitor the real-time pressure output by the pump 1 , so as to adjust the output pressure of the pump 1 .

[0019] A second pressure sensor 18 is connected to the inlet oil circuit of the motor 15 via a shuttle valve 14 . The second pressure sensor 18 is used to detect the working pressure of the motor 15 .

[0020] A balance valve 17 is provided on the inlet oil circuit of the motor 15 , which can stop the motor 15 in time and prevent the motor 15 from passively rotating.

[0021] A second relief valve 12 is connected in parallel to the inlet oil circuit of the first pressure reducing valve 13 .

[0022] The number of the control execution systems is three and they are connected in parallel to each other, so that the soil bin is stirred more fully, and the number can be increased according to the required number of different stirring rods.

[0023] The present invention has strong adaptability to slag, high system reliability, and energy saving and consumption reduction. The present invention adopts PID automatic control technology, which can realize full-automatic control of soil bin mixing, and at the same time increase manual control. First, the maximum load pressure is collected by the first pressure sensor 6, and the proportional relief valve 4 is adjusted according to the collected load pressure to achieve matching of the load pressure with the maximum output pressure of the pump. At the same time, the load value collected by the second pressure sensor 18 of each control execution system is used to adjust the opening of the proportional multi-way valve 10, thereby adjusting the stirring rod speed. When the load pressure reaches a certain value, the proportional multi-way valve 10 can also be reversed to achieve the reversal of the stirring rod. At the same time, the flow required by the entire system is calculated according to the input current of the proportional multi-way valve 10, and the electromagnetic proportional reversing valve 2 is synchronously adjusted to adjust the output displacement of the pump 1, so as to achieve matching of the load speed with the displacement of the pump 1. At the same time, the pressure sensor collects the pump outlet pressure and each load pressure, which can be fed back to the human-machine interface, and the user can understand the working conditions of each stirring rod in real time. The pressure gauge 5 is connected in parallel to the first pressure sensor 6, which can be compared with the pressure sensor value in real time to prevent the pressure sensor from failing or the value from being inaccurate and affecting the stability of the system.

[0024] The outlet of pump 1 of this system is equipped with a ball valve 7, which can be closed in time to cut off the oil source when an accident such as oil leakage occurs or when the components and pipelines need to be replaced. A precision filter 9 is installed at the outlet of pump 1 to prevent impurities such as iron filings in the oil circuit from damaging precision components such as proportional multi-way valve 10 and motor 15 in the control execution system.

[0025] This system uses a bidirectional motor 15 controlled by a proportional multi-way valve 10 to drive the stirring rod to rotate. It can be matched according to the knife disc steering speed and soil bin pressure, and the appropriate steering and speed can be selected for stirring. When a certain load pressure is too large, adaptive adjustments can be made in time to reduce the speed or reverse, making the entire system more efficient and convenient. At the same time, a bidirectional balancing valve 17 is added to the circuit to more accurately control the rotation of the stirring rod. This system is equipped with a first overflow valve 3 at the pump outlet, which can overflow in time when the proportional overflow valve 4 fails unexpectedly or the pump variable cylinder is abnormal, thereby increasing the safety of the system.

[0026] The control valve uses an integrated proportional multi-way valve 10 to save space. A pressure compensation valve 11 is added before the proportional multi-way valve 10 to ensure that the speed adjustment is independent of the load under different load conditions, making the system stable and accurate. At the same time, when more actuator motors are needed, the number of proportional multi-way valves 10 can be directly increased in parallel to realize the convenient and quick increase and decrease of the control actuator system.

[0027] The pressure oil output from the power system is divided into three parts. One part enters the proportional multi-way valve 10 through the pressure compensation valve 11; the other part enters the control oil circuit of the proportional multi-way valve 10 through the first pressure reducing valve 13, and the second overflow valve 12 is connected in parallel at the pressure oil inlet to control the maximum pressure of the entire circuit; and another part enters the working oil circuit through the second pressure reducing valve 16 for oil replenishment. After the pressure oil enters the main valve of the proportional multi-way valve, the proportional multi-way valve 10 controls the forward and reverse opening of the control valve to achieve forward and reverse rotation and speed control. After passing through the proportional multi-way valve 10, it enters the working oil circuits A and B. Before the working oil circuits A and B, the second pressure sensor 18 is connected through the shuttle valve 14 to detect the working pressure in real time. At the same time, a pressure measuring point is added to each of the working oil circuits A and B. If necessary, a pressure gauge can be used to detect the pressure of the working oil circuits A and B. Adding a balancing valve 17 to the working oil circuit can stop the motor 15 in time and prevent the motor 15 from passively rotating. The motor 15 is used as an actuator to drive the stirring rod for stirring. This embodiment uses three identical control execution systems and is connected in parallel to each other to make the soil bin more fully stirred.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. An automatic control system for a mixing device of an ultra-large diameter earth pressure balance shield machine, characterized in that: It includes a power system and a control execution system, wherein the power system includes a pump, an electromagnetic proportional reversing valve, a hydraulically controlled reversing valve, a first relief valve, a proportional relief valve, a check valve, a ball valve and a filter. The outlet of the pump leads out a control oil to connect the electromagnetic proportional reversing valve, the proportional relief valve and the hydraulically controlled reversing valve. The oil outlet of the electromagnetic proportional reversing valve is connected to the oil inlet of the hydraulically controlled reversing valve. The oil inlet of the proportional relief valve is simultaneously connected to the other side of the hydraulically controlled reversing valve. The outlet of the pump is connected in series with the ball valve, the check valve and the filter in sequence and then connected to the control execution system; the control execution system includes a pressure compensation valve, a proportional multi-way valve, a first pressure reducing valve and a second pressure reducing valve. The outlet oil circuit of the power system is respectively connected to the oil inlets of the pressure compensation valve, the first pressure reducing valve and the second pressure reducing valve. The oil outlet of the pressure compensation valve is connected to the proportional multi-way valve. The oil outlet of the first pressure reducing valve is connected to the control oil circuit of the proportional multi-way valve. The oil outlet of the second pressure reducing valve is connected to the motor, and the second pressure reducing valve enters the working oil circuit for oil replenishment; A first pressure sensor and a pressure gauge are provided on the outlet oil circuit of the pump; a second pressure sensor is connected to the inlet oil circuit of the motor via a shuttle valve; the flow rate required by the entire system is calculated according to the input current of the proportional multi-way valve, and the electromagnetic proportional reversing valve is adjusted; the first pressure sensor collects the maximum load pressure, and the proportional relief valve is adjusted according to the collected load pressure to achieve matching of the load pressure with the maximum output pressure of the pump.

2. The automatic control system for the mixing device of an ultra-large diameter earth pressure balance shield machine according to claim 1 is characterized in that: A balancing valve is arranged on the inlet oil circuit of the motor.

3. The automatic control system for the mixing device of an ultra-large diameter earth pressure balance shield machine according to claim 1 is characterized in that: A second relief valve is connected in parallel to the inlet oil circuit of the first pressure reducing valve.

4. The automatic control system of the mixing device of the super-large diameter earth pressure balance shield machine according to any one of claims 1 to 3, characterized in that: The number of the control execution systems is three and they are connected in parallel with each other.

Images