Hydraulic control system of spiral conveyor and shield tunneling machine thereof

Abstract

The utility model discloses a screw conveyer hydraulic control system and a shield tunneling machine thereof, which comprise at least one executive component and N hydraulic pumps, and N is greater than or equal to 2; a pipeline between a port A of the hydraulic pump and the executive component and a pipeline between a port B of the hydraulic pump and the executive component are respectively connected with a pressure stop valve, an overflow valve is connected between the port A and the port B of the hydraulic pump, and the hydraulic pump is connected with a pressure sensor used for detecting the pressure of a pump outlet and a proportional directional valve used for adjusting the displacement. The problem of energy waste caused by simultaneous operation of a plurality of hydraulic pumps during low-power operation of the screw machine is solved. And the problems of pressure fluctuation and impact when a plurality of hydraulic pumps are started and stopped in sequence are solved. Therefore, on the basis of ensuring the safe and stable operation of the screw machine, the operation power of the screw machine is further reduced, so that the purposes of environmental protection and energy conservation are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel construction, in particular to a hydraulic control system for a screw conveyor and a shield machine adopting the system. Background Art

[0002] Screw conveyors are the most commonly used soil conveying mechanism in shield machines. Currently, most screw conveyors are driven by hydraulic systems. While hydraulic drive offers high power density and reliability, it also suffers from low energy efficiency and high heat generation. With increasing attention to energy conservation and environmental protection, this paper proposes a hydraulic control principle for a green, energy-saving screw conveyor.

[0003] The power used by the screw conveyor of a shield machine is often relatively high, generally reaching 200-600kW, and is usually driven by a closed hydraulic system. Due to its high rated power, multiple motor pump sets are used to provide power during the design; for example, the multi-pump hydraulic system with a pilot-type normally open relief valve is disclosed in publication number CN203641173 U. In actual use, existing solutions generally do not take into account the actual power demand. Multiple motor pump sets are started and operated simultaneously, resulting in energy waste when the power demand is low. Therefore, it is necessary to design a green and energy-saving hydraulic system. Utility Model Content

[0004] In response to the deficiencies in the above-mentioned background technology, the present invention proposes a hydraulic control system for a screw conveyor and a shield machine thereof, which solves the problem of energy waste caused by the simultaneous operation of all motor pump groups when the hydraulically driven screw conveyor is activated in the prior art; and provides a solution for realizing the start-up and shutdown of multiple closed hydraulic pumps one by one.

[0005] The technical solution of the present utility model is implemented as follows: a screw conveyor hydraulic control system includes at least one actuator and N hydraulic pumps, N≥2; the pipeline between the A port of the hydraulic pump and the actuator and the pipeline between the B port of the hydraulic pump and the actuator are respectively connected with a pressure cut-off valve, an overflow valve is connected between the A port and the B port of the hydraulic pump, and the hydraulic pump is connected with a pressure sensor for detecting its pump outlet pressure and a proportional reversing valve for adjusting the displacement.

[0006] As a first solution, the pressure cut-off valve includes an electromagnetic ball valve and a two-way cartridge valve. The electromagnetic ball valve is connected to the two-way cartridge valve and the two-way cartridge valve is controlled to switch by the electromagnetic ball valve gaining or losing power.

[0007] As a second solution, the pressure cut-off valve is an electromagnetic ball valve, which controls the flow of oil in the pipeline by gaining or losing electricity through the electromagnetic ball valve.

[0008] As a third solution, the pressure cut-off valve is an electromagnetic reversing valve, which controls the flow of oil in the pipeline by gaining or losing electricity through the electromagnetic reversing valve.

[0009] Further preferably, a first pipeline is connected between port A and port B of the hydraulic pump, and a relief valve and a shuttle valve are provided in series on the first pipeline. The high-pressure side pressure oil of the hydraulic pump enters the proportional relief valve through the shuttle valve.

[0010] Further preferably, the relief valve is a proportional relief valve, which regulates the pump outlet pressure. The proportional relief valve is used to preload the pump pressure when the standby hydraulic pump is switched in and out of the system, preventing the pressure oil from impacting the hydraulic pump after the pressure isolation valve is opened.

[0011] More preferably, the actuator is a hydraulic motor, and N hydraulic pumps simultaneously provide power to the hydraulic motor. In specific construction, multiple hydraulic pumps and hydraulic motors can be configured according to actual conditions; multiple hydraulic pumps can provide power to the hydraulic motor.

[0012] Further preferably, a filter and a hydraulic displacement device are connected to the oil return pipeline of the hydraulic pump.

[0013] Further preferably, the hydraulic control system of the screw conveyor is a closed hydraulic system; in the closed system, the oil inlet pipe of the hydraulic pump is directly connected to the oil return pipe of the actuator, and the working fluid circulates in a closed manner in the system's pipeline, further increasing the stability of the system.

[0014] A shield machine comprises the screw conveyor hydraulic control system.

[0015] The beneficial effects of this utility model include: A pressure-isolating valve at the pump port prevents high-pressure oil in the system from entering an inactive hydraulic pump, thereby protecting the pump body. A proportional relief valve preloads the pump pressure when the standby hydraulic pump is switched in and out of the system, preventing pressure oil from impacting the hydraulic pump after the pressure-isolating valve opens. This system flexibly and smoothly controls the switching in and out of multiple pump sources for the screw conveyor, automatically matching the number of activated hydraulic pumps to the screw conveyor's speed, thereby achieving green and energy-saving benefits. Compared to existing operating methods, this utility model employs a green and energy-saving hydraulic control system for screw conveyors, eliminating the energy waste caused by the simultaneous operation of multiple hydraulic pumps during low-power operation. It also addresses the pressure fluctuations and shocks caused by the sequential startup and shutdown of multiple hydraulic pumps. Therefore, while ensuring safe and stable operation of the screw conveyor, this utility model further reduces the operating power of the screw conveyor, achieving green and energy-saving benefits, which is of great significance to tunnel construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a structural diagram of the utility model when two hydraulic pumps are provided.

[0018] Figure 2 for Figure 1 A partial enlarged view of . DETAILED DESCRIPTION

[0019] 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 embodiments described 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.

[0020] It should be noted that the present invention improves the equipment components and does not involve improvements to the circuits and control programs. The present invention only controls the operation and stop of various electronic devices through the PLC control system. Since the PLC control system is a mature automatic control system in industry, the present invention will not elaborate on the circuits and control programs.

[0021] In the description of the present invention, it should be understood that the terms "vertical", "lateral", "up", "down", "front", "back", "left", "right", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the invention of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention of the present invention.

[0022] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0023] like Figure 1 As shown in Example 1, a hydraulic control system for a screw conveyor comprises at least one actuator 7 and N hydraulic pumps 1, where N ≥ 2, forming a closed hydraulic system driven by multiple pump sources. Pressure shut-off valves 4 are connected to the pipeline between port A of the hydraulic pump 1 and the actuator 7, and to the pipeline between port B of the hydraulic pump 1 and the actuator 7, respectively. Specifically, a pressure shut-off valve 4 is configured for each pump port A and B. When only one hydraulic pump is required to operate, the pressure shut-off valves prevent pressurized oil from entering the other hydraulic pumps. A relief valve 3 is connected between ports A and B of the hydraulic pump 1. This proportional relief valve regulates the pump outlet pressure. The hydraulic pump 1 is connected to a pressure sensor 5 for detecting its outlet pressure and a proportional reversing valve 2 for adjusting its displacement. When the hydraulic pumps are sequentially activated, a pressure shut-off valve assembly 4 prevents oil from flowing back into unactivated hydraulic pumps. When a hydraulic pump enters operation from a standby state, the proportional relief valve 3 adjusts the pump pressure to match the system pressure. Subsequently, the pressure shut-off valve 4 opens, and the pump enters system operation. This control method is used to realize the sequential start and shut down of multiple pump sources in a closed hydraulic system.

[0024] As a preferred embodiment, the pressure cutoff valve 4 in this embodiment comprises a solenoid ball valve 41 and a two-way cartridge valve 42. The solenoid ball valve 41 is connected to the two-way cartridge valve 42, and the switching of the two-way cartridge valve 42 is controlled by the solenoid ball valve 41. The main valve of the pressure cutoff valve in this embodiment is a two-way cartridge valve 42 with a self-locking characteristic. The solenoid ball valve 41 controls the flow of pilot oil, thereby controlling the opening and closing of the pressure cutoff valve. The pressure cutoff valve 4 at the pump port prevents high-pressure oil in the system from entering an inoperative hydraulic pump, thereby protecting the pump.

[0025] As a preferred solution, a first pipeline 8 is connected between ports A and B of the hydraulic pump 1 in this embodiment. A relief valve 3 and a shuttle valve 6 are arranged in series on the first pipeline 8. A pressure isolation valve 4 controls the flow of this oil circuit. The high-pressure oil on the high-pressure side of the hydraulic pump 1 enters the proportional relief valve 3 through the shuttle valve 6.

[0026] In this embodiment, a pressure isolation valve 4 at the pump port is used to prevent high-pressure oil in the system from entering the inoperative hydraulic pump, thereby protecting the pump. The main valve of the pressure isolation valve is a two-way cartridge valve 42 with a self-locking characteristic. The on-off flow of pilot oil is controlled by a solenoid ball valve 41, thereby controlling the opening and closing of the pressure isolation valve. In addition, the system is designed with a proportional relief valve 3 at the A / B outlet of pump 1. When the standby hydraulic pump needs to be connected to the system, a smaller displacement is first given to the pump, and the proportional relief valve 3 controls the pressure at the pump outlet. When the pressure approaches the system pressure, the pressure isolation valve 4 at the pump A / B port is opened, and the pump is connected to the system and begins normal operation. When the pump needs to be disconnected from the system, the principle is similar. As a result, the system can flexibly and smoothly control the connection and disconnection of multiple pump sources of the screw conveyor, and then automatically match the number of activated hydraulic pumps according to the screw conveyor speed, thereby achieving the goal of green energy saving.

[0027] like Figure 1 、 2 As shown, Example 2 is a hydraulic control system for a screw conveyor. This embodiment is further optimized on the basis of Example 1. In this embodiment, the actuator 7 is a hydraulic motor, and N hydraulic pumps 1 provide power to the hydraulic motor at the same time. In this embodiment, two hydraulic motors and two hydraulic pumps are taken as examples. The two hydraulic pumps are hydraulic pump 1 and hydraulic pump 11 respectively; the corresponding pressure detection device on the hydraulic pump 1 is a pressure sensor 5, and the corresponding pressure detection device on the hydraulic pump 11 is a pressure sensor 51. Pressure sensor 5 and pressure sensor 51 are used to detect the pressure of the hydraulic system. In this embodiment, the main valve of the pressure isolation valve is a two-way cartridge valve 42 with a self-locking characteristic. The on-off of the pilot oil is controlled by the electromagnetic ball valve 41, thereby controlling the opening and closing of the pressure isolation valve.

[0028] Preferably, the hydraulic pump 1 in this embodiment is connected to the oil return line with a filter 9 and a hydraulic displacement device 10. The filter is used to filter the system oil, improving its cleanliness. The hydraulic displacement device 10 can utilize an existing hydraulic displacement device to allow for the timely discharge of hot oil, effectively addressing oil aging and temperature rise issues and improving operational efficiency.

[0029] The specific working process of the hydraulic control system of the screw conveyor in this embodiment is as follows:

[0030] When the system is not operating, all solenoid valves are de-energized, and the two-way cartridge valve 42 in the pressure isolation valve 4 is closed and self-locked. When the system is operating, hydraulic pump 11 starts first. When the flow rate of hydraulic pump 11 reaches maximum and the hydraulic motor 7 requires higher speed, hydraulic pump 1 automatically starts. When pump 1 starts, proportional reversing valve 2 is in neutral. The system assigns the pressure value detected by pressure sensor 51 to proportional relief valve 3. A signal of approximately 10% is then applied to proportional reversing valve 2, and pump 1 begins to output flow. At this point, the outlet pressure of pump 1 is controlled by proportional relief valve 3 and detected by pressure sensor 5. The program automatically adjusts the signal to proportional relief valve 3 based on the difference between the readings of pressure sensor 51 and pressure sensor 5 until the difference between the readings of pressure sensor 51 and pressure sensor 5 is less than 20 bar. At this point, the output pressures of pumps 1 and 11 are approximately equal. Then, the two solenoid ball valves 41 are energized, opening the two-way cartridge valve 42 in the pressure isolation valve 4, allowing the pressurized oil from pump 1 to flow smoothly into the system. At the same time, the signal of the proportional relief valve 3 is directly given to the maximum, and no more overflow occurs.

[0031] When the system switches from operating both pumps 1 and 11 simultaneously to requiring only pump 11, the system first applies a signal of approximately 10% to proportional reversing valve 2 and assigns the pressure value collected by pressure sensor 51 to proportional relief valve 3 for comparison. Once the pressure value collected by pressure sensor 51 equals the preset value for proportional relief valve 3, the system de-energizes both solenoid valves 41 and closes two-way cartridge valve 42 in pressure isolation valve 4. At this point, pump 1 is isolated from the system, and proportional reversing valve 2 and proportional relief valve 3 are de-energized, ultimately halting hydraulic pump 1.

[0032] Example 3 is a hydraulic control system for a screw conveyor. This example differs from Examples 1 or 2 in that the pressure cutoff valve is a solenoid ball valve, which controls the flow of oil in the pipeline by switching it on and off. This example uses the solenoid ball valve to control the flow of oil in the pipeline under low flow conditions. The solenoid ball valve also prevents high-pressure oil in the system from entering an inoperative hydraulic pump, thereby protecting the pump.

[0033] Example 4 is a hydraulic control system for a screw conveyor. This example differs from Examples 1 or 2 in that the pressure cutoff valve in this example is a solenoid reversing valve, which controls the flow of oil in the pipeline by switching the valve on and off. In low-flow conditions, this example uses the solenoid reversing valve to control the flow of oil in the pipeline. Furthermore, the solenoid reversing valve also prevents high-pressure oil in the system from entering an inoperative hydraulic pump, thereby protecting the pump.

[0034] Example 5, a shield machine, including a screw conveyor hydraulic control system as described in any one of Examples 1 to 4. Since the number of hydraulic pumps of the screw conveyor in the shield machine needs to be greater than or equal to 2, this embodiment also takes 2 hydraulic pumps as an example. The system is a closed system, and the system is provided with a pump source 1 and a pump source 11. The displacement of the hydraulic pump is adjusted by a proportional reversing valve 2, and the pump outlet pressure is detected by a pressure sensor 5. The actuator of the system is a hydraulic motor 7. The green and energy-saving screw machine hydraulic system is based on the above-mentioned closed hydraulic system, and a pressure isolation valve 4 and a proportional relief valve 3, as well as a shuttle valve 6 are added. The pressure isolation valve 4 can control the on-off of the oil circuit, and the high-pressure side pressure oil of the hydraulic pump 1 enters the proportional relief valve 3 through the shuttle valve 6. In this way, the sequential start-up and shutdown of the hydraulic pumps of the multi-pump source closed hydraulic system can be achieved, thereby achieving green energy saving of the hydraulic system.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A hydraulic control system for a screw conveyor, characterized in that: The invention comprises at least one actuator (7) and N hydraulic pumps (1), where N is greater than or equal to 2; a pressure cut-off valve (4) is connected to the pipeline between the A port of the hydraulic pump (1) and the actuator (7) and the pipeline between the B port of the hydraulic pump (1) and the actuator (7), respectively; an overflow valve (3) is connected between the A port and the B port of the hydraulic pump (1); and a pressure sensor (5) for detecting the pump outlet pressure and a proportional reversing valve (2) for adjusting the displacement are connected to the hydraulic pump (1).

2. The hydraulic control system for a screw conveyor according to claim 1, characterized in that: The pressure cut-off valve (4) comprises an electromagnetic ball valve (41) and a two-way cartridge valve (42), wherein the electromagnetic ball valve (41) is connected to the two-way cartridge valve (42) and the two-way cartridge valve (42) is controlled to be switched on and off by the electromagnetic ball valve (41) when electricity is supplied or discharged.

3. The hydraulic control system for a screw conveyor according to claim 1, characterized in that: The pressure cut-off valve (4) is an electromagnetic ball valve, which controls the flow of oil in the pipeline by gaining or losing power to the electromagnetic ball valve.

4. The hydraulic control system for a screw conveyor according to claim 1, characterized in that: The pressure cut-off valve (4) is an electromagnetic reversing valve, which controls the oil flow in the pipeline by gaining or losing electricity through the electromagnetic reversing valve.

5. The screw conveyor hydraulic control system according to any one of claims 1 to 4, characterized in that: A first pipeline (8) is connected between port A and port B of the hydraulic pump (1), and a relief valve (3) and a shuttle valve (6) arranged in series are provided on the first pipeline (8).

6. The hydraulic control system for a screw conveyor according to claim 5, characterized in that: The overflow valve (3) is a proportional overflow valve, which regulates the pump outlet pressure.

7. The hydraulic control system for a screw conveyor according to claim 1, characterized in that: The actuator (7) is a hydraulic motor, and N hydraulic pumps (1) simultaneously provide power to the hydraulic motor.

8. The hydraulic control system for a screw conveyor according to claim 1, characterized in that: The oil return pipeline of the hydraulic pump (1) is connected to a filter (9) and a hydraulic displacement device (10).

9. The hydraulic control system for a screw conveyor according to claim 1, characterized in that: The hydraulic control system is a closed hydraulic system.

10. A shield machine, characterized in that: It comprises a screw conveyor hydraulic control system as described in any one of claims 1 to 9.

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