Polar region drilling machine hydraulic system and control method thereof

Abstract

The invention relates to a polar region drilling machine hydraulic system and a control method thereof. The hydraulic system comprises a hydraulic pump station, a load-sensitive multi-way valve, a two-position two-way reversing valve, a low-pressure overflow valve and a power head motor. The hydraulic pump station comprises a load-sensitive pump and an oil tank, an oil outlet of the load-sensitive pump is communicated with an oil inlet of the load-sensitive multi-way valve, the load-sensitive multi-way valve comprises a first working unit, and the first working unit is communicated with the power head motor; an LS port of the load-sensitive multi-way valve is divided into two branches, one branch is communicated with a control oil port of the load-sensitive pump, the other branch is communicated with a first working oil port of the two-position two-way reversing valve, a second working oil port of the two-position two-way reversing valve is communicated with an oil inlet of the low-pressure overflow valve, and an oil return port of the low-pressure overflow valve is communicated with the oil tank. The polar region drilling machine hydraulic system has the beneficial effects that the load-sensitive pump and the load-sensitive multi-way valve are adopted to form a load-sensitive system, the load change can be responded in real time, the energy consumption of the system is reduced, and the stability of the system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polar drilling rigs, and in particular to a hydraulic system of a polar drilling rig and a control method thereof. Background Art

[0002] A polar drilling rig is a special drilling equipment designed for extremely cold environments and needs to operate under extreme conditions such as low temperatures of -50°C to -60°C, strong winds, and ice and snow coverage. It mainly serves two fields: resource exploration and scientific research. Its core functions include ice layer penetration, bedrock sampling, oil and gas development, etc., and it is a key tool for polar resource development and geoscience research. Due to the extremely cold polar environment, the labor intensity of personnel will be very high, so automation, light weight, and high efficiency are considered as much as possible in the drilling process. For example, the drill pipe can adopt an aluminum alloy rod body plus a steel joint, which not only reduces the weight but also ensures the strength of the drill pipe. At the same time, in order to meet the wireline coring process, a wireline coring drill pipe is also equipped.

[0003] Chinese patent document CN105350907A discloses a hydraulic multi-functional drilling rig, including a fuselage platform, a mast arranged on the surface of the fuselage platform, a mast support for supporting one end of the mast, and a mast stay for driving the other end of the mast to rotate. A power head for driving the drill tool to move is slidably arranged on the mast, and a chuck for circumferentially fixing the drill tool is arranged at one end of the mast. A power head bracket for carrying itself is arranged at the bottom of the power head, a slide rail is arranged on the surface of the mast along its length direction, and the power head bracket is slidably arranged on the slide rail. A chuck for clamping the drill tool is arranged at the outlet of the power head, and the chuck is coaxial with the chuck.

[0004] Chinese patent document CN118997661A discloses an integrated above - ground and underground kilometer - directional drilling rig, including: a mast for supporting the drill pipes and drill bit of the drilling rig; a power head assembly provided on the mast for driving the drill pipes and drill bit to perform drilling operations; a chassis assembly provided below the mast; a gripper fixing seat provided on the mast for installing an above - ground angle - adjusting oil cylinder or an underground angle - adjusting oil cylinder; the gripper fixing seat includes a gripper mounting plate for installing a drill pipe clamping structure, and a connecting plate fixedly connected to the gripper mounting plate; a feed oil cylinder mounting seat for installing the power head assembly is provided below the connecting plate; an underground drilling connecting plate is provided on the side of the feed oil cylinder away from the connecting plate. The power head assembly includes: a feed mechanism provided inside the mast; a power head support seat provided on the feed oil cylinder barrel of the feed mechanism; and a power head provided on the power head support seat. The feed mechanism includes a feed oil cylinder and a feed mechanism connecting seat provided on the chassis assembly. When the feed mechanism works, the barrel of the feed oil cylinder expands and contracts, driving the power head support seat and the power head thereon to move synchronously. The drilling rig further includes: a steel wire rope provided on the mast; a traveling block for lifting and lowering the drill pipe during drilling, respectively connected to one end of the steel wire rope and the upper end of the drill pipe; and a winch connected to the other end of the steel wire rope for controlling the lifting and lowering of the traveling block.

[0005] Chinese patent document CN118148524A discloses a drill pipe grasping manipulator for a drilling rig, including a mounting frame, a horizontal moving device, a flipping device, and a manipulator; the horizontal moving device is provided on the mounting frame, the fixed end of the flipping device is provided on the horizontal moving device, the movable end of the flipping device is hinged to the first connection point of the manipulator, the second connection point of the manipulator is hinged to one side of the horizontal moving device, and the flipping device pushes the first connection point of the manipulator to rotate around the second connection point so that the clamping axis of the manipulator is parallel to the axis of the drill pipe; the manipulator clamps and drives the drill pipe to move along its axis to move the drill pipe away from or close to the ground, and the horizontal moving device drives the drill pipe to move to the placement area of the drill pipe placement rack through the manipulator.

[0006] The defects and deficiencies of traditional hydraulic multi - function drilling rigs are as follows: (1) There is a high - pressure overflow valve set for the rotation of the power head of traditional drilling rigs. However, the polar drilling process is complex. When using wire - line coring drill pipes, the wire - line coring drill pipes are small - diameter thin - wall drill pipes, and the strength of their joints is low. If the make - up and break - out are carried out at the set maximum pressure, the threads of the wire - line coring drill pipes will be damaged; (2) The tool winch of traditional drilling rigs does not follow the power head. Therefore, when adding or removing drill pipes, the swivel and the kelly bar need to be manually removed and hung on the side of the mast, and then connected to the drill pipe during drilling, which increases the labor intensity of the personnel. Summary of the Invention

[0007] (1) Technical problems to be solved In view of the above-mentioned disadvantages and deficiencies of the prior art, the present invention provides a hydraulic system for a polar drilling rig and its control method, which solves the technical problem that when using a small-diameter thin-walled drill pipe for drilling in the wireline coring process, the existing maximum rotary pressure of the power head of the drilling rig cannot be limited twice, resulting in damage to the thread during make-up and break-out operations.

[0008] (2) Technical solutions To achieve the above object, the main technical solutions adopted by the present invention include: In a first aspect, an embodiment of the present invention provides a hydraulic system for a polar drilling rig, including a hydraulic pump station, a load-sensing multi-way valve, a two-position two-way directional control valve, a low-pressure relief valve, and an actuator. The actuator includes a power head motor; The hydraulic pump station includes a load-sensing pump and a fuel tank. The oil outlet of the fuel tank is connected to the oil inlet of the load-sensing pump, the oil outlet of the load-sensing pump is connected to the oil inlet of the load-sensing multi-way valve, the oil return port of the load-sensing multi-way valve is connected to the fuel tank, and the load-sensing multi-way valve includes a first working bank, which is connected to the power head motor to control the rotation direction and rotation speed of the power head motor; The LS port of the load-sensing multi-way valve is divided into two branches. One branch is connected to the control oil port of the load-sensing pump, and the other branch is connected to the first working oil port of the two-position two-way directional control valve. The second working oil port of the two-position two-way directional control valve is connected to the oil inlet of the low-pressure relief valve, and the oil return port of the low-pressure relief valve is connected to the fuel tank.

[0009] Optionally, it further includes a first pressure reducing valve. The hydraulic pump station further includes a constant pressure pump, and the power head motor is a variable displacement hydraulic motor; The oil outlet of the fuel tank is connected to the oil inlet of the constant pressure pump, the oil outlet of the constant pressure pump is connected to the oil inlet of the first pressure reducing valve, the drain port of the first pressure reducing valve is connected to the fuel tank, and the oil outlet of the first pressure reducing valve is connected to the control oil port of the power head motor; The constant pressure pump can pump high-pressure oil to the first pressure reducing valve, and the oil outlet of the first pressure reducing valve can output low-pressure oil after pressure reduction to the control oil port of the power head motor, thereby controlling the displacement of the power head motor.

[0010] Optionally, the actuator further includes a fishing winch; The load-sensing multi-way valve further includes a second working bank, which is connected to the fishing winch to control the rotation direction and rotation speed of the fishing winch; A first two-way balance valve is provided on the pipeline between the second working bank and the fishing winch, and the first two-way balance valve is used to control the smooth lowering of the fishing winch and keep it in a set position.

[0011] Optionally, the actuator further includes a tool winch and a first shuttle valve; The load-sensing multi-way valve further includes a third working connection, which is connected to the tool winch to control the rotation direction and rotation speed of the tool winch; a brake is provided on the tool winch, and a first shuttle valve is provided in the control circuit of the tool winch. The first shuttle valve can output the high-pressure hydraulic oil in the working circuit of the tool winch to open the brake to release the braking of the tool winch.

[0012] Optionally, it further includes a second pressure reducing valve, a two-position four-way directional control valve and a second shuttle valve; The oil outlet of the constant pressure pump is connected to the oil inlet of the second pressure reducing valve. The oil outlet of the second pressure reducing valve is connected to the first working oil port of the two-position four-way directional control valve. The oil drain port of the second pressure reducing valve and the second working oil port of the two-position four-way directional control valve are both connected to the oil tank; the third working oil port of the two-position four-way directional control valve is closed, the fourth working oil port of the two-position four-way directional control valve is connected to the first oil inlet of the second shuttle valve, the second oil inlet of the second shuttle valve is connected to the oil outlet of the first shuttle valve, and the oil outlet of the second shuttle valve is connected to the brake; When the spool of the two-position four-way directional control valve is in the first position, the first working oil port of the two-position four-way directional control valve is connected to the closed third working oil port, and the second working oil port of the two-position four-way directional control valve is connected to the fourth working oil port; when the spool of the two-position four-way directional control valve is in the second position, the first working oil port of the two-position four-way directional control valve is connected to the fourth working oil port, and the second working oil port of the two-position four-way directional control valve is connected to the closed third working oil port.

[0013] Optionally, the actuator further includes a feed cylinder; The load-sensing multi-way valve further includes a fourth working connection, which is connected to the feed cylinder to control the movement direction and movement speed of the feed cylinder.

[0014] Optionally, it further includes an electro-hydraulic proportional multi-way valve. The actuator further includes: a left-right translation cylinder, a front-back translation cylinder, a jaw clamping cylinder, a rod feeding motor and a jaw tilting cylinder; The oil outlet and the oil return port of the hydraulic pump station are respectively connected to the corresponding oil ports of the electro-hydraulic proportional multi-way valve one by one. The electro-hydraulic proportional multi-way valve includes a fifth working connection, a sixth working connection, a seventh working connection, an eighth working connection and a ninth working connection. The fifth working connection is connected to the left-right translation cylinder, the sixth working connection is connected to the front-back translation cylinder, the seventh working connection is connected to the jaw clamping cylinder, the eighth working connection is connected to the rod feeding motor, and the ninth working connection is connected to the jaw tilting cylinder.

[0015] Optionally, a hydraulic lock is provided on the pipeline between the seventh working connection and the jaw clamping cylinder, a second two-way balance valve is provided on the pipeline between the eighth working connection and the rod feeding motor, and a third two-way balance valve is provided on the pipeline between the ninth working connection and the jaw tilting cylinder.

[0016] Second aspect, an embodiment of the present invention provides a control method for the above-mentioned hydraulic system of a polar drilling rig, including the following steps: When the polar drilling rig drills other drill pipes except the wireline coring drill pipe, the two-position two-way directional valve cuts off the pipeline between the LS port of the load-sensing multi-way valve and the low-pressure relief valve. The load-sensing pump pumps the hydraulic oil in the fuel tank to the load-sensing multi-way valve. The hydraulic oil flowing out of the LS port of the load-sensing multi-way valve completely flows to the control oil port of the load-sensing pump. The pump outlet pressure of the load-sensing pump is adjusted according to the following formula: ; where, P 泵出口 is the pump outlet pressure of the load-sensing pump; P LS1 is the LS port pressure of the load-sensing multi-way valve; ΔP is a fixed pressure difference, with a magnitude of 1.4 - 2.2 MPa; When the polar drilling rig drills the wireline coring drill pipe, the two-position two-way directional valve connects the pipeline between the LS port of the load-sensing multi-way valve and the low-pressure relief valve. The load-sensing pump pumps the hydraulic oil in the fuel tank to the load-sensing multi-way valve. Part of the hydraulic oil flowing out of the LS port of the load-sensing multi-way valve flows to the control oil port of the load-sensing pump, and the other part flows to the low-pressure relief valve. At this time, the pump outlet pressure of the load-sensing pump is adjusted according to the following formula: ; where, P 泵出口 is the pump outlet pressure of the load-sensing pump; P LS2 is the LS port pressure of the load-sensing multi-way valve, and P LS2 is less than or equal to the set pressure P 设定 of the low-pressure relief valve; ΔP is a fixed pressure difference, with a magnitude of 1.4 - 2.2 MPa.

[0017] Optionally, it further includes the following steps: When the tool winch needs to follow the power head motor, switch the spool of the two-position four-way directional valve to the second position, so that the first working oil port and the fourth working oil port of the two-position four-way directional valve are connected. The constant pressure pump supplies high-pressure oil to the second pressure reducing valve. The drain port of the second pressure reducing valve returns the excess oil to the fuel tank. The oil outlet of the second pressure reducing valve outputs the reduced low-pressure oil, which enters the brake through the two-position four-way directional valve and the second shuttle valve in sequence, driving the brake to release the brake on the tool winch.

[0018] (III) Beneficial effects The beneficial effects of the present invention are as follows: The hydraulic system of the polar drilling rig of the present invention includes a hydraulic pump station, a load-sensing multi-way valve, a two-position two-way reversing valve, a low-pressure relief valve, and an actuator. The actuator includes a power head motor. The hydraulic pump station includes a load-sensing pump and a fuel tank. The oil outlet of the fuel tank is connected to the oil inlet of the load-sensing pump. The oil outlet of the load-sensing pump is connected to the oil inlet of the load-sensing multi-way valve. The oil return port of the load-sensing multi-way valve is connected to the fuel tank. The load-sensing multi-way valve includes a first working connection, which is connected to the power head motor to control the rotation direction and rotation speed of the power head motor. The LS port of the load-sensing multi-way valve is divided into two branches. One branch is connected to the control oil port of the load-sensing pump, and the other branch is connected to the first working oil port of the two-position two-way reversing valve. The second working oil port of the two-position two-way reversing valve is connected to the oil inlet of the low-pressure relief valve. The oil return port of the low-pressure relief valve is connected to the fuel tank. Compared with the existing hydraulic system of the polar drilling rig, the hydraulic system of the polar drilling rig of the present invention uses a load-sensing pump and a load-sensing valve to form a load-sensing system, which can achieve precise matching of pressure and flow with load requirements, ensuring high efficiency and energy saving of the system. In addition, in the hydraulic system of the polar drilling rig of the present invention, a two-position two-way reversing valve and a low-pressure relief valve are connected in parallel at the Ls port of the load-sensing valve. Therefore, when the power head of the hydraulic system of the polar drilling rig of the present invention is used to screw on and off the wireline coring drill pipe, the two-position two-way reversing valve can be opened to connect the pipeline between the LS port of the load-sensing multi-way valve and the low-pressure relief valve, so that the maximum rotation pressure of the power head is reduced to the set value of the low-pressure relief valve, preventing thread damage.

[0019] The hydraulic system of the polar drilling rig of the present invention delivers pilot control oil to the power head motor through a constant pressure pump and a first pressure reducing valve. The pilot control oil pushes the servo spool of the power head motor to move, so as to control the displacement of the power head motor, thereby realizing dynamic adjustment of the output torque and rotation speed of the power head motor to optimize the system efficiency and meet the requirements of complex working conditions.

[0020] The hydraulic system of the polar drilling rig of the present invention further includes a tool winch, a first shuttle valve, a second pressure reducing valve, a two-position four-way directional control valve, and a second shuttle valve. The oil outlet of the constant pressure pump is connected to the oil inlet of the second pressure reducing valve. The oil outlet of the second pressure reducing valve is connected to the first working oil port of the two-position four-way directional control valve. The oil drain port of the second pressure reducing valve and the second working oil port of the two-position four-way directional control valve are both connected to the oil tank. The third working oil port of the two-position four-way directional control valve is closed. The fourth working oil port of the two-position four-way directional control valve is connected to the first oil inlet of the second shuttle valve. The second oil inlet of the second shuttle valve is connected to the oil outlet of the first shuttle valve. The oil outlet of the second shuttle valve is connected to the brake. Compared with the existing hydraulic system of the polar drilling rig, the hydraulic system of the polar drilling rig of the present invention can switch the spool of the two-position four-way directional control valve to the second position, so that the first working oil port and the fourth working oil port of the two-position four-way directional control valve are connected. The constant pressure pump supplies high-pressure oil to the second pressure reducing valve. The oil drain port of the second pressure reducing valve returns the excess oil to the oil tank. The oil outlet of the second pressure reducing valve outputs the reduced-pressure low-pressure oil, which enters the brake through the two-position four-way directional control valve and the second shuttle valve in sequence, driving the brake to release the braking of the tool winch. Thus, the tool winch can follow the power head motor, that is, the tool winch can synchronously descend with the power head during drilling. Therefore, the tool winch of the present invention can always lift the swivel and the kelly during both drilling and adding or removing drill pipes, which avoids frequent disassembly and assembly of the tool winch, the swivel, and the kelly, thereby significantly reducing the manual labor intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 FIG. 6 is a schematic structural diagram of Embodiment 1 of the hydraulic system of the polar drilling rig of the present invention; Figure 2 FIG. 9 is a schematic structural diagram of Embodiment 3 of the hydraulic system of the polar drilling rig of the present invention.

[0022]

DESCRIPTION OF THE REFERENCE NUMERALS

[0023] For a better explanation and understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Embodiment 1:

[0025] Referring to Figure 1 , this embodiment provides a hydraulic system for a polar drill, which includes a hydraulic pump station 1, a load-sensing multi-way valve 2, a two-position two-way directional valve 7, a low-pressure relief valve 8, and an actuator. The actuator includes a power head motor 3, a fishing winch 4, a tool winch 5, and a feed cylinder 6. It should be noted that the function of the power head motor 3 is to transmit power to the drill pipe and the drill bit, driving the drill bit to break rocks or formations; the fishing winch 4 is used to drive the fishing tool to lift and lower, so as to grab downhole falling objects or core barrels; the tool winch 5 is connected to the drill string through a steel wire rope, and is used for tripping the drill string, casing, downhole tools, as well as assisting in tasks such as making and breaking connections, and hoisting equipment; the feed cylinder 6 is used to control the axial feed movement of the drill string (drill pipe, drill bit), so as to achieve precise adjustment of the drilling pressure, lifting of the drill string, and drilling requirements for dealing with complex formations.

[0026] The hydraulic pump station 1 includes a load-sensing pump 101 and a fuel tank 102. The oil outlet of the fuel tank 102 is communicated with the oil inlet of the load-sensing pump 101. The oil outlet of the load-sensing pump 101 is communicated with the oil inlet of the load-sensing multi-way valve 2. The oil return port of the load-sensing multi-way valve 2 is communicated with the fuel tank 102. The load-sensing multi-way valve 2 includes a first working bank, and the first working bank is communicated with the power head motor 3 to control the rotation direction and rotation speed of the power head motor 3.

[0027] The LS port of the load-sensing multi-way valve 2 is divided into two branches. One branch is communicated with the control oil port of the load-sensing pump 101, and the other branch is communicated with the first working oil port of the two-position two-way directional valve 7. The second working oil port of the two-position two-way directional valve 7 is communicated with the oil inlet of the low-pressure relief valve 8, and the oil return port of the low-pressure relief valve 8 is communicated with the fuel tank 102.

[0028] It should be noted that the LS port of the load-sensing multi-way valve 2 is a load-sensing port. The load-sensing multi-way valve 2 can monitor the load pressures of each actuator in the hydraulic system in real time, and feedback the highest load pressure to the load-sensing pump 101 to form a closed-loop control. The load-sensing pump 101 can, according to the feedback signal of the load-sensing multi-way valve 2, adjust the displacement of the pump (such as the swash plate angle or the plunger stroke) in real time to match the flow rate required by the system, avoiding the generation of redundant flow. The pump outlet pressure P of the load-sensing pump 101 泵出口It is always higher than the highest system load pressure by a fixed pressure difference ΔP. The two-position two-way directional control valve 7 is a most basic hydraulic control component, having two working positions and two passages, mainly used to control the on-off of hydraulic oil and realize the connection or cut-off of pipelines. The low-pressure relief valve 8 is a pressure control valve, mainly used to control the oil pressure in the hydraulic system and prevent the system pressure from exceeding the set value.

[0029] The working process of the hydraulic system of the polar drill in this embodiment is as follows: When the power head motor 3 rotates normally to drive other drill pipes except the wireline coring drill pipe for drilling operations, the two-position two-way directional control valve 7 cuts off the pipeline between the LS port of the load-sensitive multi-way valve 2 and the low-pressure relief valve 8, so that the hydraulic oil flowing out of the LS port of the load-sensitive multi-way valve 2 completely flows to the control oil port of the load-sensitive pump 101. The pump outlet pressure of the load-sensitive pump 101 is adjusted according to the following formula: ; where, P 泵出口 is the pump outlet pressure of the load-sensitive pump 101; P LS1 is the pressure at the LS port of the load-sensitive multi-way valve 2; ΔP is the fixed pressure difference, with a magnitude of 1.4 - 2.2 MPa.

[0030] It should be noted that other drill pipes except the wireline coring drill pipe can be drill pipes with an aluminum alloy rod body + steel joints. Since the steel joints have high strength and can withstand the highest pressure of the hydraulic system; at this time, the oil circuit between the low-pressure relief valve 8 and the LS port of the load-sensitive multi-way valve 2 is cut off by the two-position two-way directional control valve 7, and the pump outlet pressure of the load-sensitive pump 101 is output according to the highest load pressure of the actuator.

[0031] When the power head motor 3 of this embodiment drills the wireline coring drill pipe, since the strength of the joint of the wireline coring drill pipe is low, the rotation pressure during make-up and break-out will build up to the highest pressure of the system, thus damaging the thread of the wireline coring drill pipe. To solve the above problems, the load-sensitive pump 101 needs to reduce the pump outlet pressure P 泵出口 . At this time, the two-position two-way directional control valve 7 connects the pipeline between the LS port of the load-sensitive multi-way valve 2 and the low-pressure relief valve 8. At this time, part of the hydraulic oil flowing out of the LS port of the load-sensitive multi-way valve 2 flows to the control oil port of the load-sensitive pump 101, and the other part flows to the low-pressure relief valve 8. The set pressure of the low-pressure relief valve 8 is P 设定 . When the inlet oil pressure of the low-pressure relief valve 8 is greater than P 设定 , its spool opens, and the excess oil flows back to the oil tank 102 to maintain the system pressure constant. At this time, the pump outlet pressure of the load-sensitive pump 101 is adjusted according to the following formula: ; where, P泵出口 is the pump outlet pressure of the load-sensing pump 101; P LS2 is the LS port pressure of the load-sensing multi-way valve 2, and P LS2 is less than or equal to the set pressure P of the low-pressure relief valve 8 设定 ; ΔP is a fixed pressure difference, with a magnitude of 1.4 - 2.2 MPa.

[0032] In the hydraulic system of the polar drill rig in this embodiment, a two-position two-way directional valve is used to connect the low-pressure relief valve 8 to the Ls oil circuit of the load-sensing multi-way valve 2, thereby reducing the maximum pump outlet pressure of the load-sensing pump 101 to the set value of the low-pressure relief valve 8, thus reducing the rotary torque and protecting the thread of the wireline core drill pipe.

[0033] Furthermore, the hydraulic system of the polar drill rig in this embodiment further includes a first pressure reducing valve 9. The hydraulic pump station 1 further includes a constant-pressure pump 103, and the power head motor 3 is a variable-displacement hydraulic motor. The oil outlet of the oil tank 102 is connected to the oil inlet of the constant-pressure pump 103, the oil outlet of the constant-pressure pump 103 is connected to the oil inlet of the first pressure reducing valve 9, the drain port of the first pressure reducing valve 9 is connected to the oil tank 102, and the oil outlet of the first pressure reducing valve 9 is connected to the control oil port of the power head motor 3. The constant-pressure pump 103 can pump high-pressure oil to the first pressure reducing valve 9, and the oil outlet of the first pressure reducing valve 9 can output the reduced-pressure low-pressure oil to the control oil port of the power head motor 3, thereby controlling the displacement of the power head motor 3. The drain port of the first pressure reducing valve 9 returns the excess oil to the oil tank 102 to ensure stable pressure.

[0034] In the hydraulic system of the polar drill rig in this embodiment, through the constant-pressure pump 103 and the first pressure reducing valve 9, pilot control oil is supplied to the power head motor 3. The pilot control oil pushes the servo spool of the power head motor 3 to move, so as to control the displacement of the power head motor 3, thereby realizing dynamic adjustment of the output torque and speed of the power head motor 3 to optimize the system efficiency and meet the requirements of complex working conditions.

[0035] In this embodiment, the load-sensing multi-way valve 2 further includes a second working connection, which is connected to the fishing winch 4 to control the rotation direction and rotation speed of the fishing winch 4. A first two-way balance valve 15 is provided on the pipeline between the second working connection and the fishing winch 4, and the first two-way balance valve 15 is used to control the smooth lowering of the fishing winch 4 and keep it in the set position.

[0036] It should be noted that the first two-way balance valve 15 is arranged in the control circuit of the fishing winch 4 to balance the pressure and control the flow of the hydraulic circuit, so that the fishing winch 4 can be lowered smoothly and kept in the set position, thereby ensuring the smoothness of the standby state of the fishing winch 4.

[0037] In this embodiment, the hydraulic system of the polar drill also includes a first shuttle valve 13. The load-sensing multi-way valve 2 further includes a third working connection, and the third working connection communicates with the tool winch 5 to control the rotation direction and rotation speed of the tool winch 5. A brake 12 is provided on the tool winch 5, and a first shuttle valve 13 is provided in the control circuit of the tool winch 5. The oil outlet of the first shuttle valve 13 communicates with the brake 12. The first shuttle valve 13 can output the high-pressure oil in the working circuit of the tool winch 5 to open the brake 12 to release the braking of the tool winch 5.

[0038] It should be noted that when the third working connection works and supplies oil to the tool winch 5, the two oil inlets of the first shuttle valve 13 respectively receive the input pressures from two different oil circuits. The oil outlet of the first shuttle valve 13 outputs the higher-pressure one of the two oil inlets, and at the same time closes the other one, thereby driving the brake 12 to release the braking of the tool winch 5 so that the tool winch 5 can operate normally. When the third working connection does not work, the pressure in the control circuit of the tool winch 5 is balanced, and the first shuttle valve 13 cannot draw high-pressure oil. At this time, the brake 12 brakes the tool winch 5.

[0039] Furthermore, the hydraulic system of the polar drill in this embodiment also includes a second pressure reducing valve 10, a two-position four-way directional control valve 11 and a second shuttle valve 14. The oil outlet of the constant-pressure pump 103 communicates with the oil inlet of the second pressure reducing valve 10. The oil outlet of the second pressure reducing valve 10 communicates with the first working oil port of the two-position four-way directional control valve 11. The oil drain port of the second pressure reducing valve 10 and the second working oil port of the two-position four-way directional control valve 11 both communicate with the oil tank 102. The third working oil port of the two-position four-way directional control valve 11 is closed, and the fourth working oil port of the two-position four-way directional control valve 11 communicates with the first oil inlet of the second shuttle valve 14. The second oil inlet of the second shuttle valve 14 communicates with the oil outlet of the first shuttle valve 13. The oil outlet of the second shuttle valve 14 communicates with the brake 12.

[0040] When the spool of the two-position four-way directional control valve 11 is in the first position, the first working oil port of the two-position four-way directional control valve 11 communicates with the closed third working oil port, and the second working oil port of the two-position four-way directional control valve 11 communicates with the fourth working oil port; when the spool of the two-position four-way directional control valve 11 is in the second position, the first working oil port of the two-position four-way directional control valve 11 communicates with the fourth working oil port, and the second working oil port of the two-position four-way directional control valve 11 communicates with the closed third working oil port.

[0041] It should be noted that when the spool of the two-position four-way directional control valve 11 is in the first position, the second working oil port of the two-position four-way directional control valve 11 is communicated with the fourth working oil port, so that the first oil inlet of the second shuttle valve 14 is communicated with the oil tank 102, that is, the pressure at the first oil inlet of the second shuttle valve 14 is 0. In this case, if the third working union works and supplies oil to the tool winch 5, the first shuttle valve 13 draws out the high-pressure oil in the control circuit of the tool winch 5 and enters the brake 12 through the second shuttle valve 14 to drive the brake 12 to release the brake on the tool winch 5; if the third working union does not work, the pressure in the control circuit of the tool winch 5 is balanced, and the first shuttle valve 13 cannot draw out the high-pressure oil, that is, the pressure at the second oil inlet of the second shuttle valve 14 is 0. At this time, the second shuttle valve 14 cannot draw out the high-pressure oil either, so the brake 12 brakes the tool winch 5.

[0042] When the spool of the two-position four-way directional control valve 11 is in the second position and the constant-pressure pump 103 supplies high-pressure oil to the second pressure reducing valve 10, the first working oil port of the two-position four-way directional control valve 11 is communicated with the fourth working oil port. The outlet of the second pressure reducing valve 10 outputs the low-pressure oil after pressure reduction, and enters the brake 12 through the two-position four-way directional control valve 11 and the second shuttle valve 14 in sequence to drive the brake 12 to release the brake on the tool winch 5. The drain port of the second pressure reducing valve 10 returns the excess oil to the oil tank 102 to ensure stable pressure. When the third working union does not work, the constant-pressure pump 103 can also drive the brake 12 on the tool winch 5 to release the brake on the tool winch 5, so that the tool winch 5 can follow up with the power head motor 3.

[0043] The advantage that the tool winch 5 can follow up with the power head motor 3 is that it is not necessary to frequently carry the swivel and the kelly. This significantly reduces the labor intensity of the workers. Specifically, during the process of adding or removing drill pipes of the drilling rig, it is necessary to clear the central passage of the power head. At this time, the tool winch needs to lift the swivel and the kelly, and the workers then hold the swivel and the kelly and swing them to the side of the mast and hang them. After adding or removing the drill pipes, during the drilling process of the drilling rig, the swivel and the kelly need to be connected to the power head and are driven by the power head to drill downward. During this process, the tool winch of the traditional drilling rig does not lift the swivel and the kelly. Each time an operation of adding or removing drill pipes is performed, the operator needs to constantly move and hang between the central passage of the power head and the side of the mast, and the labor intensity of the workers is great. In contrast, the tool winch 5 of this embodiment can follow the power head and move downward synchronously during drilling. Therefore, the tool winch 5 of this embodiment can always lift the swivel and the kelly whether during drilling or adding or removing drill pipes, which avoids the frequent carrying of the swivel and the kelly, thus significantly reducing the labor intensity of the workers.

[0044] In this embodiment, the load-sensing multi-way valve 2 further includes a fourth working connection, which is connected to the feed cylinder 6 to control the movement direction and speed of the feed cylinder 6.

[0045] Further, a first pressure gauge is provided on the pipeline between the fourth working connection and the rod chamber of the feed cylinder 6, and a second pressure gauge is provided on the pipeline between the fourth working connection and the rodless chamber of the feed cylinder 6. It should be noted that the first pressure gauge and the second pressure gauge are low-temperature resistant pressure gauges.

[0046] The polar drill of this embodiment can be equipped with a 3-meter drill pipe to reduce the frequency of making and breaking joints and improve the drilling efficiency.

[0047] Further, an electric tracing heating device can be provided on the pipelines between the various components in the hydraulic system of the polar drill. This electric tracing heating device can emit a certain amount of heat, and supplement the loss of the traced pipeline through direct or indirect heat exchange to meet the normal working requirements of heating up, heat preservation or anti-freezing.

[0048] Embodiment 2:

[0049] This embodiment provides a control method for the hydraulic system of the polar drill described in Embodiment 1, including the following steps: When the polar drill drills other drill pipes except the wireline coring drill pipe, the two-position two-way directional valve 7 cuts off the pipeline between the LS port of the load-sensing multi-way valve 2 and the low-pressure relief valve 8, and the load-sensing pump 101 pumps the hydraulic oil in the oil tank 102 to the load-sensing multi-way valve 2. The hydraulic oil flowing out from the LS port of the load-sensing multi-way valve 2 completely flows to the control oil port of the load-sensing pump 101, and the pump outlet pressure of the load-sensing pump 101 is adjusted according to the following formula: ; where, P 泵出口 is the pump outlet pressure of the load-sensing pump 101; P LS1 is the pressure of the LS port of the load-sensing multi-way valve 2; ΔP is a fixed pressure difference, with a magnitude of 1.4 - 2.2 MPa; When the polar drill drills the wireline coring drill pipe, the two-position two-way directional valve 7 connects the pipeline between the LS port of the load-sensing multi-way valve 2 and the low-pressure relief valve 8. The load-sensing pump 101 pumps the hydraulic oil in the oil tank 102 to the load-sensing multi-way valve 2. Part of the hydraulic oil flowing out from the LS port of the load-sensing multi-way valve 2 flows to the control oil port of the load-sensing pump 101, and the other part flows to the low-pressure relief valve 8. At this time, the pump outlet pressure of the load-sensing pump 101 is adjusted according to the following formula: ; where, P 泵出口is the pump outlet pressure of the load-sensing pump 101; P LS2 is the LS port pressure of the load-sensing multi-way valve 2, and P LS2 is less than or equal to the set pressure P of the low-pressure overflow valve 8 设定 ; ΔP is a fixed pressure difference, with a magnitude of 1.4 - 2.2 MPa.

[0050] For the parts that are the same as those in Embodiment 1, they will not be elaborated here.

[0051] Embodiment 3: The polar drill of this embodiment can be equipped with an automated drill pipe manipulator, which not only reduces the labor intensity of personnel during the process of hoisting and lowering the drill pipe, but also improves the operation efficiency.

[0052] See Figure 2 , this embodiment provides another hydraulic system for a polar drill, which further includes an electro-hydraulic proportional multi-way valve 16. The actuators further include: a left-right translation cylinder 17, a front-back translation cylinder 18, a jaw clamping cylinder 19, a rod feeding motor 21, and a jaw tilting cylinder 20. It should be noted that the left-right translation cylinder 17, the front-back translation cylinder 18, the jaw clamping cylinder 19, the rod feeding motor 21, and the jaw tilting cylinder 20 serve as the actuators of the drill pipe grasping manipulator for the drill. The jaw clamping cylinder 19 is used to drive the jaws of the manipulator to clamp the drill pipe; the left-right translation cylinder 17 is used to drive the manipulator to carry the drill pipe for left-right translation; the front-back translation cylinder 18 is used to drive the manipulator to carry the drill pipe for front-back translation; the jaw tilting cylinder 20 is used to drive the manipulator to carry the drill pipe for tilting movement to adjust the posture of the drill pipe; the rod feeding motor 21 is used to drive the drill pipe to move along its axis direction.

[0053] The oil outlet of the constant pressure pump 103 and the oil return port of the oil tank 102 are respectively and correspondingly connected to the corresponding oil ports of the electro-hydraulic proportional multi-way valve 16. The electro-hydraulic proportional multi-way valve 16 includes a fifth working connection, a sixth working connection, a seventh working connection, an eighth working connection, and a ninth working connection. The fifth working connection is connected to the left-right translation cylinder 17, the sixth working connection is connected to the front-back translation cylinder 18, the seventh working connection is connected to the jaw clamping cylinder 19, the eighth working connection is connected to the rod feeding motor 21, and the ninth working connection is connected to the jaw tilting cylinder 20.

[0054] Furthermore, a hydraulic lock 22 is provided on the pipeline between the seventh working connection and the jaw clamping cylinder 19, a second two-way balance valve 23 is provided on the pipeline between the eighth working connection and the rod feeding motor 21, and a third two-way balance valve 24 is provided on the pipeline between the ninth working connection and the jaw tilting cylinder 20. It should be noted that the hydraulic lock 22 can seal the oil in the cylinder, enabling the cylinder to remain stationary for a long time. The hydraulic lock 22 enables the actuator to operate smoothly and lock when stopped.

[0055] The rest which is the same as that in Embodiment 1 will not be described herein again.

[0056] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0057] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected to", "fixed" and the like should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium; it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] In the present invention, unless otherwise clearly defined and limited, when a first feature is "on" or "under" a second feature, it may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, when a first feature is "above", "over" and "on top of" a second feature, it may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. When a first feature is "under", "below" and "beneath" a second feature, it may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0059] In the description of this specification, the descriptions of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without conflict, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0060] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A polar drilling rig hydraulic system, characterized in that: It comprises a hydraulic pump station (1), a load-sensitive multi-way valve (2), a two-position two-way reversing valve (7), a low-pressure relief valve (8) and an actuator, wherein the actuator comprises a power head motor (3); The hydraulic pump station (1) comprises a load-sensitive pump (101) and an oil tank (102); the oil outlet of the oil tank (102) is connected to the oil inlet of the load-sensitive pump (101); the oil outlet of the load-sensitive pump (101) is connected to the oil inlet of a load-sensitive multi-way valve (2); the oil return port of the load-sensitive multi-way valve (2) is connected to the oil tank (102); the load-sensitive multi-way valve (2) comprises a first working joint, the first working joint is connected to a power head motor (3), and is used to control the rotation direction and rotation speed of the power head motor (3); The LS port of the load-sensing multi-way valve (2) is divided into two branches, one branch is connected to the control oil port of the load-sensing pump (101), and the other branch is connected to the first working oil port of the two-position two-way reversing valve (7). The second working oil port of the two-position two-way reversing valve (7) is connected to the oil inlet of the low-pressure relief valve (8), and the oil return port of the low-pressure relief valve (8) is connected to the oil tank (102).

2. The polar drilling rig hydraulic system according to claim 1, characterized in that: It also includes a first pressure reducing valve (9), the hydraulic pump station (1) also includes a constant pressure pump (103), and the power head motor (3) is a variable displacement hydraulic motor; The oil outlet of the oil tank (102) is connected to the oil inlet of the constant pressure pump (103), the oil outlet of the constant pressure pump (103) is connected to the oil inlet of the first pressure reducing valve (9), the oil drain port of the first pressure reducing valve (9) is connected to the oil tank (102), and the oil outlet of the first pressure reducing valve (9) is connected to the control oil port of the power head motor (3); The constant pressure pump (103) can pump high-pressure oil to the first pressure reducing valve (9), and the oil outlet of the first pressure reducing valve (9) can output the reduced-pressure low-pressure oil to the control oil outlet of the power head motor (3), thereby controlling the displacement of the power head motor (3).

3. The polar drilling rig hydraulic system according to claim 1, characterized in that: The actuator also includes a salvage winch (4); The load-sensitive multi-way valve (2) further comprises a second working connection, the second working connection being in communication with the salvage winch (4) and being used to control the rotation direction and rotation speed of the salvage winch (4); A first two-way balancing valve (15) is provided on the pipeline between the second working joint and the salvage winch (4), and the first two-way balancing valve (15) is used to control the salvage winch (4) to be lowered steadily and maintained at a set position.

4. The polar drilling rig hydraulic system according to claim 2, characterized in that: The actuator also includes a tool winch (5) and a first shuttle valve (13); The load-sensitive multi-way valve (2) further comprises a third working link, which is connected to the tool winch (5) and is used to control the rotation direction and rotation speed of the tool winch (5); a brake (12) is provided on the tool winch (5); a first shuttle valve (13) is provided in the control circuit of the tool winch (5); an oil outlet of the first shuttle valve (13) is connected to the brake (12); the first shuttle valve (13) can output high-pressure oil in the working circuit of the tool winch (5) to open the brake (12) and release the brake on the tool winch (5).

5. The polar drilling rig hydraulic system according to claim 4, characterized in that: It also includes a second pressure reducing valve (10), a two-position four-way reversing valve (11) and a second shuttle valve (14); The oil outlet of the constant pressure pump (103) is connected to the oil inlet of the second pressure reducing valve (10), the oil outlet of the second pressure reducing valve (10) is connected to the first working oil outlet of the two-position four-way reversing valve (11), the oil drain port of the second pressure reducing valve (10) and the second working oil outlet of the two-position four-way reversing valve (11) are both connected to the oil tank (102); the third working oil outlet of the two-position four-way reversing valve (11) is closed, the fourth working oil outlet of the two-position four-way reversing valve (11) is connected to the first oil inlet of the second shuttle valve (14), the second oil inlet of the second shuttle valve (14) is connected to the oil outlet of the first shuttle valve (13), and the oil outlet of the second shuttle valve (14) is connected to the brake (12); When the valve core of the two-position four-way reversing valve (11) is located in the first position, the first working oil port of the two-position four-way reversing valve (11) is connected to the closed third working oil port, and the second working oil port of the two-position four-way reversing valve (11) is connected to the fourth working oil port; when the valve core of the two-position four-way reversing valve (11) is located in the second position, the first working oil port of the two-position four-way reversing valve (11) is connected to the fourth working oil port, and the second working oil port of the two-position four-way reversing valve (11) is connected to the closed third working oil port.

6. The polar drilling rig hydraulic system according to claim 5, characterized in that: The actuator also includes a feed cylinder (6); The load-sensitive multi-way valve (2) further comprises a fourth working connection, which is connected to the feed cylinder (6) and is used to control the movement direction and movement speed of the feed cylinder (6).

7. The polar drilling rig hydraulic system according to claim 5, characterized in that: It also includes an electric proportional multi-way valve (16), and the actuator also includes: a left-right translation cylinder (17), a front-back translation cylinder (18), a clamping claw clamping cylinder (19), a rod feeding motor (21) and a clamping claw tilting cylinder (20); The oil outlet and the oil return port of the hydraulic pump station (1) are respectively connected to the corresponding oil ports of the electric proportional multi-way valve (16) in a one-to-one correspondence. The electric proportional multi-way valve (16) includes a fifth working joint, a sixth working joint, a seventh working joint, an eighth working joint and a ninth working joint. The fifth working joint is connected to the left and right translation cylinder (17), the sixth working joint is connected to the front and rear translation cylinder (18), the seventh working joint is connected to the clamping cylinder (19), the eighth working joint is connected to the rod feeding motor (21), and the ninth working joint is connected to the clamping cylinder (20).

8. The polar drilling rig hydraulic system according to claim 7, characterized in that: A hydraulic lock (22) is provided on the pipeline between the seventh working joint and the clamping jaw clamping cylinder (19), a second two-way balancing valve (23) is provided on the pipeline between the eighth working joint and the rod feeding motor (21), and a third two-way balancing valve (24) is provided on the pipeline between the ninth working joint and the clamping jaw tilting cylinder (20).

9. A control method for a polar drilling rig hydraulic system according to any one of claims 5 to 8, characterized in that: The following steps are involved: When the polar drilling rig is drilling drill rods other than the rope coring drill rod, the two-position two-way reversing valve (7) cuts off the pipeline between the LS port of the load sensing multi-way valve (2) and the low-pressure relief valve (8), and the load sensing pump (101) pumps the hydraulic oil in the oil tank (102) to the load sensing multi-way valve (2). The hydraulic oil flowing out of the LS port of the load sensing multi-way valve (2) completely flows to the control oil port of the load sensing pump (101). The pump outlet pressure of the load sensing pump (101) is adjusted according to the following formula: ； Among them, P 泵出口 is the pump outlet pressure of the load sensing pump (101); P LS1 is the LS port pressure of the load sensing multi-way valve (2); ΔP is a fixed pressure difference, which is 1.4-2.2MPa; When the polar drilling rig is drilling a rope coring drill rod, the two-position two-way reversing valve (7) connects the pipeline between the LS port of the load sensing multi-way valve (2) and the low-pressure relief valve (8), and the load sensing pump (101) pumps the hydraulic oil in the oil tank (102) to the load sensing multi-way valve (2). Part of the hydraulic oil flowing out of the LS port of the load sensing multi-way valve (2) flows to the control oil port of the load sensing pump (101), and the other part flows to the low-pressure relief valve (8). At this time, the pump outlet pressure of the load sensing pump (101) is adjusted according to the following formula: ； Among them, P 泵出口 is the pump outlet pressure of the load sensing pump (101); P LS2 is the LS port pressure of the load sensing multi-way valve (2), and P LS2 Less than or equal to the set pressure P of the low-pressure relief valve (8) 设定 ; ΔP is a fixed pressure difference, which is 1.4-2.2MPa.

10. The control method of the polar drilling rig hydraulic system according to claim 9, characterized in that: The following steps are also included: When the tool winch (5) needs to follow the power head motor (3), the valve core of the two-position four-way reversing valve (11) is switched to the second position, so that the first working oil port of the two-position four-way reversing valve (11) is connected to the fourth working oil port, and the constant pressure pump (103) supplies high-pressure oil to the second pressure reducing valve (10), and the oil drain port of the second pressure reducing valve (10) returns the excess oil to the oil tank (102), and the oil outlet of the second pressure reducing valve (10) outputs the reduced-pressure low-pressure oil, which enters the brake (12) after passing through the two-position four-way reversing valve (11) and the second shuttle valve (14) in sequence, and drives the brake (12) to release the brake on the tool winch (5).

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