Hydraulic control system and heading machine

Abstract

The invention provides a hydraulic control system and a heading machine, and the hydraulic control system comprises a motor; a plurality of hydraulic control units, each hydraulic control unit comprising: a hydraulic pump connected with the motor; the hydraulic pump is communicated with the multi-way valve; the electro-hydraulic proportional variable displacement mechanism is installed on the hydraulic pump and used for controlling the opening degree of the hydraulic pump. The pressure detection assembly comprises a first pressure transmitter and a second pressure transmitter, the first pressure transmitter is used for detecting the pressure of an outlet of the hydraulic pump, and the second pressure transmitter is used for detecting the pressure of a load sensitive opening of the multi-way valve; and the programmable logic controller is respectively connected with the first pressure transmitter and the second pressure transmitter, and the programmable logic controller is connected with the electro-hydraulic proportional variable displacement mechanism so as to control the electro-hydraulic proportional variable displacement mechanism according to a signal of the pressure detection assembly. And a plurality of pumps on the programmable logic controller can be uniformly controlled and adjusted.

Description

Technical Field

[0001] This application relates to the field of tunneling machine technology, and more specifically, to a hydraulic control system and a tunneling machine. Background Technology

[0002] Existing tunneling machine systems are generally load-sensitive systems. Load-sensitive systems have advantages such as high energy efficiency and the load flow rate is not affected by the load size before the flow rate is saturated. Pumps generally have functions such as pressure cut-off by mechanical-hydraulic feedback, constant power, and load sensitivity, which can limit the power value of a single pump. However, there is no interconnection between multiple pumps, and under special working conditions, the capacity of a single pump cannot be fully utilized.

[0003] Therefore, how to enable multiple pumps to communicate with each other and fully utilize the capabilities of each pump has become an urgent problem to be solved. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art or related technologies.

[0005] Therefore, the first aspect of this application provides a hydraulic control system.

[0006] A second aspect of this application provides a tunneling machine.

[0007] In view of the above, a first aspect of this application proposes a hydraulic control system, comprising: a motor; a plurality of hydraulic control units, each hydraulic control unit including: a hydraulic pump, the input shaft of which is connected to the output shaft of the motor; a multi-way valve, the outlet of which is connected to the inlet of which is connected to the outlet ...

[0008] The hydraulic control system proposed in this application includes a motor and multiple hydraulic control units. Each hydraulic control unit includes a hydraulic pump, a multi-way valve, an electro-hydraulic proportional displacement mechanism, and a pressure detection component. The input shaft of the hydraulic pump is connected to the output shaft of the motor, and is driven to rotate by the motor. The outlet of the hydraulic pump is connected to the inlet of the multi-way valve to supply pressurized oil to the multi-way valve. The electro-hydraulic proportional displacement mechanism is mounted on the hydraulic pump, and its function is to adjust the displacement of the hydraulic pump, i.e., control the output flow of the hydraulic pump. The pressure detection component includes a first pressure transmitter and a second pressure transmitter. The first pressure transmitter is used to detect the pressure at the outlet of the hydraulic pump, and the second pressure transmitter is used to detect the pressure at the load-sensitive port of the multi-way valve. A programmable logic controller (PLC) is the control core of the entire system. Its input terminals are connected to the signal output terminals of the first and second pressure transmitters in each hydraulic control unit, respectively, to receive pressure signals. The output terminal of the PLC is connected to the control interface of the electro-hydraulic proportional displacement mechanism in each hydraulic control unit. Based on the received pressure signal, the programmable logic controller (PLC) calculates and outputs control commands to the electro-hydraulic proportional variable displacement mechanism, thereby adjusting the hydraulic pump's displacement in real time and achieving precise system control. The hydraulic control system replaces traditional mechanical hydraulic feedback with electronic control, enabling flexible and stable control of the pressure difference between the pump outlet pressure and the load-sensitive port pressure. Since the pressure in the hydraulic control system can be controlled by the PLC, each device connected to the PLC can be controlled and adjusted, ensuring that the total power in the entire hydraulic control system remains constant. Furthermore, power can be freely distributed as needed, allowing multiple pumps to interact and fully utilize each pump, thus guaranteeing operational requirements.

[0009] Optionally, in any of the above technical solutions, the hydraulic control system further includes a proportional amplifier; the input terminal of the proportional amplifier is connected to the output terminal of the programmable logic controller; and the output terminal of the proportional amplifier is connected to the control interface of the electro-hydraulic proportional displacement mechanism in each hydraulic control unit.

[0010] In these technical solutions, the hydraulic control system also incorporates a proportional amplifier. The input of the proportional amplifier is connected to the output of the programmable logic controller (PLC), while its output is connected to the control interface of the electro-hydraulic proportional displacement mechanism in each hydraulic control unit. The proportional amplifier amplifies the weak electrical control signal output from the PLC and converts it into a strong electrical signal capable of driving the electro-hydraulic proportional displacement mechanism, ensuring the reliability and accuracy of the control. This is a common electrical interface implementation method that separates control and drive functions, facilitating modular system design and maintenance.

[0011] In any of the above technical solutions, optionally, the programmable logic controller, the proportional amplifier, the electro-hydraulic proportional displacement mechanism of the hydraulic control unit, the first pressure transmitter of the hydraulic control unit, and the second pressure transmitter of the hydraulic control unit together constitute a pressure closed-loop control structure. The pressure closed-loop control structure is used to maintain the pressure difference between the hydraulic pump outlet pressure of the hydraulic control unit and the pressure at the load-sensitive port of the multi-way valve of the hydraulic control unit.

[0012] In these technical solutions, for any hydraulic control unit, a pressure closed-loop control circuit is formed by a programmable logic controller (PLC), a proportional amplifier, an electro-hydraulic proportional displacement mechanism of the hydraulic control unit, a first pressure transmitter, and a second pressure transmitter. The PLC continuously compares the measured value of the hydraulic pump outlet pressure (detected by the first pressure transmitter) with the measured value of the multi-way valve load-sensitive port pressure (detected by the second pressure transmitter), and calculates the pressure difference between the two. This pressure difference is compared with the target pressure difference set internally by the PLC. Based on the deviation value, a control signal is output through the proportional amplifier to drive the electro-hydraulic proportional displacement mechanism to adjust the hydraulic pump displacement, ultimately ensuring that the hydraulic pump outlet pressure is always higher than the multi-way valve load-sensitive port pressure by a constant set value. This closed-loop control structure can effectively maintain a stable pressure difference, unaffected by load fluctuations, thereby ensuring the stability of the actuator speed.

[0013] Optionally, in any of the above technical solutions, the hydraulic control unit further includes a speed sensor, which is used to detect the speed of the hydraulic pump, and the signal output terminal of the speed sensor is connected to the input terminal of the programmable logic controller.

[0014] In these technical solutions, each hydraulic control unit also incorporates a speed sensor. The speed sensor detects the actual speed of the hydraulic pump and feeds its signal back to the input of the programmable logic controller (PLC). By introducing speed information, the PLC can more accurately calculate the actual output power of the hydraulic pump (power ≈ pressure × displacement × speed), providing a foundation for more accurate constant power control. For example, it can more precisely limit the pump's power when the motor speed fluctuates.

[0015] Optionally, in any of the above technical solutions, the hydraulic control system further includes a display device, which is communicatively connected to the programmable logic controller and is used to display the pressure at the outlet of the hydraulic pump and the pressure at the load-sensitive port of the multi-way valve.

[0016] In these technical solutions, the hydraulic control system also includes a display device, which is communicatively connected to the programmable logic controller (PLC). The display device is used to display the pressure values ​​at the outlet of the hydraulic pump in each hydraulic control unit and the pressure values ​​at the load-sensitive ports of the multi-way valves in real time. This provides operators with an intuitive interface for monitoring the system's operating status, facilitating observation of system pressure and load conditions and timely detection of abnormalities.

[0017] Optionally, in any of the above technical solutions, the display device includes an input unit for setting power parameters for each hydraulic control unit.

[0018] In these technical solutions, the display device further integrates an input unit, such as a touchscreen or physical buttons. Operators can use this input unit to set personalized power parameters for each hydraulic control unit, such as the power limit value for a single hydraulic pump. This makes adjusting system parameters more convenient, without requiring direct modification of the programmable logic controller (PLC) program.

[0019] Optionally, in any of the above technical solutions, the programmable logic controller may have a pre-stored power threshold corresponding to the power parameters of each hydraulic control unit.

[0020] In these technical solutions, the programmable logic controller (PLC) pre-stores power thresholds corresponding to the power parameters set for each hydraulic control unit. After the power parameters are set via the display device, the PLC automatically recalls or calculates the corresponding power threshold, which serves as the comparison benchmark for subsequent constant power control algorithms. This ensures the accuracy and rapid response of power control.

[0021] In any of the above technical solutions, optionally, the number of hydraulic control units is two, namely a first hydraulic control unit and a second hydraulic control unit; the working port of the multi-way valve of the first hydraulic control unit is connected to a first actuator, the first actuator including a hydraulic motor or cylinder for driving the star wheel and the conveying mechanism; the working port of the multi-way valve of the second hydraulic control unit is connected to a second actuator, the second actuator including a travel motor for driving the travel mechanism and a cylinder for driving the cutting arm.

[0022] In these technical solutions, the hydraulic control system specifically includes two hydraulic control units: a first hydraulic control unit and a second hydraulic control unit. The working port of the multi-way valve of the first hydraulic control unit is connected to a first actuator, which includes a hydraulic motor or cylinder that drives a star wheel (for collecting materials) and a conveying mechanism. The working port of the multi-way valve of the second hydraulic control unit is connected to a second actuator, which includes a travel motor that drives the tunneling machine and a cylinder that drives the cutting arm to lift or swing.

[0023] A second aspect of the present invention provides a tunneling machine, comprising: a hydraulic control system as described in any of the above technical solutions.

[0024] In this technical solution, since the tunneling machine includes the hydraulic control system of any of the above technical solutions, the tunneling machine has all the beneficial effects of the hydraulic control system of any of the above technical solutions.

[0025] In any of the above technical solutions, optionally, the tunneling machine body includes: a first actuator, which includes a hydraulic motor or cylinder for driving the star wheel and the conveying mechanism; and a second actuator, which includes a travel motor for driving the traveling mechanism and a cylinder for driving the cutting arm.

[0026] Additional aspects and advantages of this application will become apparent in the following description or may be learned by practice of this application. Attached Figure Description

[0027] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0028] Figure 1 One of the structural schematic diagrams of a hydraulic control system according to one embodiment of this application is shown;

[0029] Figure 2 The second schematic diagram shows the structure of a hydraulic control system according to one embodiment of this application.

[0030] The components include: 1 hydraulic control system, 10 motor, 12 hydraulic control unit, 121 hydraulic pump, 123 multi-way valve, 125 electro-hydraulic proportional variable displacement mechanism, 127 pressure detection component, 128 first pressure transmitter, 129 second pressure transmitter, 14 programmable logic controller, 16 proportional amplifier, 18 speed sensor, 19 display device, and 2 oil tank. Detailed Implementation

[0031] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0032] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0033] The following is combined with, for example Figure 1 and Figure 2To further illustrate a hydraulic control system 1 in this embodiment, the hydraulic control system 1 includes a motor 10 and multiple hydraulic control units 12. Each hydraulic control unit 12 includes a hydraulic pump 121, a multi-way valve 123, an electro-hydraulic proportional variable displacement mechanism 125, and a pressure detection component 127. The input shaft of the hydraulic pump 121 is connected to the output shaft of the motor 10 and is driven to rotate by the motor 10. The outlet of the hydraulic pump 121 is connected to the oil inlet of the multi-way valve 123 to provide pressurized oil to the multi-way valve 123. The electro-hydraulic proportional variable displacement mechanism 125 is mounted on the hydraulic pump 121 and its function is to adjust the displacement of the hydraulic pump 121, that is, to control the output flow of the hydraulic pump 121. The pressure detection component 127 includes a first pressure transmitter 128 and a second pressure transmitter 129. The first pressure transmitter 128 is used to detect the pressure at the outlet of the hydraulic pump 121, and the second pressure transmitter 129 is used to detect the pressure at the load-sensitive port of the multi-way valve 123. The programmable logic controller 14 is the control core of the entire system. Its input terminals are connected to the signal output terminals of the first pressure transmitter 128 and the second pressure transmitter 129 in each hydraulic control unit 12, respectively, to receive pressure signals. The output terminal of the programmable logic controller 14 is connected to the control interface of the electro-hydraulic proportional variable displacement mechanism 125 in each hydraulic control unit 12. Based on the received pressure signals, the programmable logic controller 14 outputs control commands to the electro-hydraulic proportional variable displacement mechanism 125 after calculation, thereby adjusting the displacement of the hydraulic pump 121 in real time and realizing precise control of the system. The hydraulic control system 1 replaces the traditional mechanical hydraulic feedback with electronic control, realizing flexible and stable control of the pressure difference between the pump outlet pressure and the load-sensitive port pressure. Since the pressure in the hydraulic control system can be controlled by the programmable logic controller 14, each device connected to the programmable logic controller 14 can be controlled and adjusted, so that the total power in the entire hydraulic control system is always the same, and the power can be freely distributed as needed, thereby ensuring the working requirements.

[0034] In any of the above embodiments, optionally, the hydraulic control system further includes a proportional amplifier 16; the input terminal of the proportional amplifier 16 is connected to the output terminal of the programmable logic controller 14; the output terminal of the proportional amplifier 16 is connected to the control interface of the electro-hydraulic proportional displacement mechanism 125 in each hydraulic control unit 12.

[0035] In these embodiments, the hydraulic control system also includes a proportional amplifier 16. The input of the proportional amplifier 16 is connected to the output of the programmable logic controller 14, and its output is connected to the control interface of the electro-hydraulic proportional displacement mechanism 125 in each hydraulic control unit 12. The function of the proportional amplifier 16 is to amplify the weak electrical control signal output from the programmable logic controller 14 and convert it into a strong electrical signal capable of driving the electro-hydraulic proportional displacement mechanism 125, ensuring the reliability and accuracy of the control. This is a common electrical interface implementation method that separates control and drive functions, facilitating modular system design and maintenance.

[0036] In any of the above embodiments, optionally, the programmable logic controller 14, the proportional amplifier 16, the electro-hydraulic proportional displacement mechanism 125 of the hydraulic control unit 12, the first pressure transmitter 128 of the hydraulic control unit 12, and the second pressure transmitter 129 of the hydraulic control unit 12 together constitute a pressure closed-loop control structure. The pressure closed-loop control structure is used to maintain the pressure difference between the outlet pressure of the hydraulic pump 121 of the hydraulic control unit 12 and the pressure at the load-sensitive port of the multi-way valve 123 of the hydraulic control unit 12.

[0037] In these embodiments, for any hydraulic control unit 12, a pressure closed-loop control loop is formed by a programmable logic controller 14, a proportional amplifier 16, an electro-hydraulic proportional displacement mechanism 125 of the hydraulic control unit 12, a first pressure transmitter 128, and a second pressure transmitter 129. The programmable logic controller 14 continuously compares the measured values ​​of the outlet pressure of the hydraulic pump 121 (detected by the first pressure transmitter 128) and the load-sensitive port pressure of the multi-way valve 123 (detected by the second pressure transmitter 129), calculating the pressure difference between the two. This pressure difference is compared with a target pressure difference set internally by the programmable logic controller 14. Based on the deviation value, a control signal is output through the proportional amplifier 16 to drive the electro-hydraulic proportional displacement mechanism 125 to adjust the displacement of the hydraulic pump 121, ultimately ensuring that the outlet pressure of the hydraulic pump 121 is always higher than the load-sensitive port pressure of the multi-way valve 123 by a constant set value. This closed-loop control structure effectively maintains a stable pressure difference, unaffected by load fluctuations, thereby ensuring the stability of the actuator speed.

[0038] In any of the above embodiments, optionally, the hydraulic control unit 12 further includes a speed sensor 18, which is used to detect the speed of the hydraulic pump 121, and the signal output terminal of the speed sensor 18 is connected to the input terminal of the programmable logic controller 14.

[0039] In these embodiments, each hydraulic control unit 12 is further equipped with a speed sensor 18. The speed sensor 18 is used to detect the actual speed of the hydraulic pump 121 and feeds its signal back to the input of the programmable logic controller 14. With the introduction of speed information, the programmable logic controller 14 can more accurately calculate the actual output power of the hydraulic pump 121 (power ≈ pressure × displacement × speed), providing a basis for achieving more accurate constant power control. For example, when the speed of the motor 10 fluctuates, the power of the pump can be more precisely limited.

[0040] In any of the above embodiments, the hydraulic control system may optionally include a display device 19, which is communicatively connected to the programmable logic controller 14 and is used to display the pressure at the outlet of the hydraulic pump 121 and the pressure at the load-sensitive port of the multi-way valve 123.

[0041] In these embodiments, the hydraulic control system further includes a display device 19, which is communicatively connected to the programmable logic controller 14. The display device 19 is used to display in real time the pressure at the outlet of the hydraulic pump 121 in each hydraulic control unit 12 and the pressure values ​​at the load-sensitive port of the multi-way valve 123. This provides operators with an intuitive interface for monitoring the system's operating status, facilitating observation of system pressure and load conditions and timely detection of abnormalities.

[0042] In any of the above embodiments, the display device 19 may optionally include an input unit for setting power parameters for each hydraulic control unit 12.

[0043] In these embodiments, the display device 19 further integrates an input unit, such as a touchscreen or physical buttons. Operators can use this input unit to set personalized power parameters for each hydraulic control unit 12, such as the power limit value for a single hydraulic pump 121. This makes adjusting system parameters more convenient, without requiring direct modification of the programmable logic controller 14 program.

[0044] In any of the above embodiments, optionally, the programmable logic controller 14 pre-stores a power threshold corresponding to the power parameters of each hydraulic control unit 12.

[0045] In these embodiments, the programmable logic controller 14 pre-stores power thresholds corresponding to the power parameters set for each hydraulic control unit 12. After the power parameters are set via the display device 19, the programmable logic controller 14 automatically calls or calculates the corresponding power threshold as a comparison benchmark for subsequent constant power control algorithms. This ensures the accuracy and rapid response of power control.

[0046] In any of the above embodiments, optionally, there are two hydraulic control units 12, namely a first hydraulic control unit and a second hydraulic control unit; the working port of the multi-way valve 123 of the first hydraulic control unit is connected to a first actuator, the first actuator including a hydraulic motor or cylinder for driving the star wheel and the conveying mechanism; the working port of the multi-way valve 123 of the second hydraulic control unit is connected to a second actuator, the second actuator including a travel motor for driving the travel mechanism and a cylinder for driving the cutting arm.

[0047] In these embodiments, the hydraulic control system specifically includes two hydraulic control units 12, namely a first hydraulic control unit and a second hydraulic control unit. The working port of the multi-way valve 123 of the first hydraulic control unit is connected to a first actuator, which includes a hydraulic motor or cylinder that drives a star wheel (for collecting materials) and a conveying mechanism. The working port of the multi-way valve 123 of the second hydraulic control unit is connected to a second actuator, which includes a travel motor that drives the tunneling machine to travel and a cylinder that drives the cutting arm to lift or swing.

[0048] A second aspect of the invention provides a tunneling machine comprising a hydraulic control system as described in any of the above embodiments.

[0049] In this embodiment, since the tunneling machine includes the hydraulic control system of any of the above embodiments, the tunneling machine has all the beneficial effects of the hydraulic control system of any of the above embodiments.

[0050] In any of the above embodiments, optionally, the tunneling machine body includes: a first actuator, the first actuator including a hydraulic motor or cylinder for driving the star wheel and the conveying mechanism; and a second actuator including a travel motor for driving the traveling mechanism and a cylinder for driving the cutting arm.

[0051] Hydraulic pump 121 controls the star wheel, hydraulic cylinder, and travel motor. After the tunneling machine is started, hydraulic pump 121, driven by motor 10, draws oil from oil tank 2 and supplies oil to multi-way valve 123. Since multi-way valve 123 has a closed-core structure, the pressure at port P1 increases. The first pressure transmitter 128 feeds back the pressure at port P1 to programmable logic controller 14, and the second pressure transmitter 129 feeds back the pressure at port LS1 to programmable logic controller 14. Programmable logic controller 14 calculates the two pressure values ​​through its internal control algorithm and drives the electro-hydraulic proportional displacement mechanism 125 through proportional amplifier 16 to reduce the displacement of hydraulic pump 121, thus lowering the pressure at port P1. By detecting the pressure at port P1 and port LS1, programmable logic controller 14 controls the displacement of hydraulic pump 121 through its internal control algorithm, ensuring that the pressure at port P1 of hydraulic pump 121 is always greater than the pressure at port LS1 by a set value. This value can be changed and set at any time by programmable logic controller 14, forming a closed-loop pressure control. Similarly, hydraulic pump 121 can also form a closed-loop pressure control.

[0052] During operation, the programmable logic controller 14 can calculate the output power of the hydraulic pump 121 at this time based on four parameters: the output current of the hydraulic pump 121, the displacement of the hydraulic pump 121, and the speed of the hydraulic pump 121, through the first pressure transmitter 128 and the proportional amplifier 16. When the calculated value is greater than the power limit value of the hydraulic pump 121, the drive current of the hydraulic pump 121 is reduced, and the displacement of the hydraulic pump 121 is reduced, thereby achieving the constant power function.

[0053] Similarly, hydraulic pump 121 can also achieve constant power function. The power limit values ​​of hydraulic pump 121 are stored in the programmable logic controller 14, so the power limit values ​​of hydraulic pump 121 can be adjusted and set separately at any time. Furthermore, both hydraulic pump 121 and hydraulic pump 121 are driven by motor 10. During use, a total power limit value is set to protect motor 10; the total power limit value is the sum of the power limit values ​​of hydraulic pump 121 and hydraulic pump 121.

[0054] Under extreme operating conditions, most of the total power limit can be allocated to the control star wheel and hydraulic pump 121, while a small portion of the total power limit can be allocated to the control cylinder's hydraulic pump 121. This allocation ratio can be adjusted on the user interface via the display device 19. Similarly, most of the total power limit can be allocated to the control cylinder's hydraulic pump 121, while a small portion of the total power limit can be allocated to the control star wheel and hydraulic pump 121.

[0055] When the hydraulic pump is worn and the output power is at a constant power point, the hydraulic pump 121 and its power limit value can be modified through the user interface of the display device 19, thereby temporarily increasing the output flow of the hydraulic pump.

[0056] Multiple pumps can be set with a total power limit to protect the motor.

[0057] In special operating conditions, the program can prioritize allocating most of the power limits to a single pump, making the actuators it controls work more smoothly.

[0058] When the hydraulic pump is worn and its output power reaches the constant power point, the output flow rate of the hydraulic pump can be increased.

[0059] In this application, the term "multiple" refers to two or more unless otherwise expressly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0060] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0061] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hydraulic control system, characterized in that, include: Electric motor; Multiple hydraulic control units, each of the hydraulic control units comprising: A hydraulic pump, wherein the input shaft of the hydraulic pump is connected to the output shaft of the motor; A multi-way valve, wherein the outlet of the hydraulic pump is connected to the inlet of the multi-way valve; An electro-hydraulic proportional variable displacement mechanism is mounted on the hydraulic pump and is used to control the opening degree of the hydraulic pump. A pressure detection assembly, comprising a first pressure transmitter and a second pressure transmitter, wherein the first pressure transmitter is used to detect the pressure at the outlet of the hydraulic pump, and the second pressure transmitter is used to detect the pressure at the load-sensitive port of the multi-way valve. A programmable logic controller (PLC) is provided, wherein the input terminals of the PLC are respectively connected to the signal output terminals of the first pressure transmitter and the second pressure transmitter in each hydraulic control unit, and the output terminal of the PLC is connected to the control interface of the electro-hydraulic proportional displacement mechanism in each hydraulic control unit, so as to control the electro-hydraulic proportional displacement mechanism according to the signal of the pressure detection component.

2. The hydraulic control system according to claim 1, characterized in that, It also includes a proportional amplifier; The input terminal of the proportional amplifier is connected to the output terminal of the programmable logic controller; The output of the proportional amplifier is connected to the control interface of the electro-hydraulic proportional displacement mechanism in each of the hydraulic control units.

3. The hydraulic control system according to claim 2, characterized in that, The programmable logic controller, the proportional amplifier, the electro-hydraulic proportional displacement mechanism of the hydraulic control unit, the first pressure transmitter of the hydraulic control unit, and the second pressure transmitter of the hydraulic control unit together constitute a pressure closed-loop control structure. The pressure closed-loop control structure is used to maintain the pressure difference between the hydraulic pump outlet pressure of the hydraulic control unit and the load-sensitive port pressure of the multi-way valve of the hydraulic control unit.

4. The hydraulic control system according to claim 1, characterized in that, The hydraulic control unit also includes a speed sensor for detecting the speed of the hydraulic pump, and the signal output terminal of the speed sensor is connected to the input terminal of the programmable logic controller.

5. The hydraulic control system according to claim 1, characterized in that, It also includes a display device, which is communicatively connected to the programmable logic controller, for displaying the pressure at the outlet of the hydraulic pump and the pressure at the load-sensitive port of the multi-way valve.

6. The hydraulic control system according to claim 5, characterized in that, The display device includes an input unit for setting power parameters for each of the hydraulic control units.

7. The hydraulic control system according to claim 6, characterized in that, The programmable logic controller has pre-stored power thresholds corresponding to the power parameters of each hydraulic control unit.

8. The hydraulic control system according to any one of claims 1 to 7, characterized in that, The number of hydraulic control units is two, namely a first hydraulic control unit and a second hydraulic control unit; The working port of the multi-way valve of the first hydraulic control unit is connected to a first actuator, which includes a hydraulic motor or cylinder for driving the star wheel and the conveying mechanism. The working port of the multi-way valve of the second hydraulic control unit is connected to a second actuator, which includes a travel motor for driving the travel mechanism and a cylinder for the cutting arm.

9. A tunneling machine, characterized in that, It includes the tunneling machine body and the hydraulic control system as described in any one of claims 1 to 8.

10. The tunneling machine according to claim 9, characterized in that, The tunneling machine body includes: a first actuator, which includes a hydraulic motor or cylinder for driving the star wheel and the conveying mechanism; The second actuator includes a travel motor for driving the traveling mechanism and a hydraulic cylinder for the cutting arm.

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