Hydraulic system of engineering geological exploration drilling rig

Abstract

The present application relates to a kind of hydraulic systems of engineering geological survey drilling machine, including oil tank, constant pressure pump, floating valve group and feed cylinder;The oil inlet of floating valve group is connected with the oil outlet of constant pressure pump, the oil return port is connected with oil tank, and two working oil ports are respectively connected with the large cavity and small cavity of feed cylinder;Floating valve group includes parallelly connected first pressure reducing valve, second pressure reducing valve, first overflow valve and second overflow valve, and has three working states of disconnect state, make-up floating state and unmake-up floating state: when make-up floating state, the hydraulic oil output by constant pressure pump enters small cavity through first pressure reducing valve, and the hydraulic oil in large cavity flows back to oil tank through first overflow valve;When unmake-up floating state, the hydraulic oil output by constant pressure pump enters large cavity through second pressure reducing valve, and the hydraulic oil in small cavity flows back to oil tank through second overflow valve.The present application makes power head in make-up and unmake-up two directions can be independently balanced dead weight, and drill pipe thread contact pressure can be respectively calibrated and accurately controlled, thereby effectively protecting drill pipe thread.

Description

Technical Field

[0001] This invention relates to the field of hydraulic systems for drilling rigs, and more particularly to a hydraulic system for an engineering geological exploration drilling rig. Background Technology

[0002] In core drilling operations such as tripping in and out of the drill string, the repeated tightening and loosening of the drill rod is a high-frequency, critical operation. For power head drilling rigs, this process typically relies on the coordinated operation of the power head and the borehole holder to engage and disengage the threads on the drill rod. The disengagement operation often requires greater torque to complete smoothly due to potential thread engagement or wear. Meanwhile, the floating function of the power head is a core design feature of this type of drilling rig for enabling drill rod tightening and loosening: by allowing the power head to move freely axially, it can adapt in real time to the axial displacement generated during thread engagement or disengagement, preventing the drill rod threads from being strained or deformed due to forced force, thereby extending the service life of the drill rod and improving construction economy.

[0003] For example, Chinese patent document CN223089657U discloses a hydraulic system for controlling the power head to float axially with the thread, such as Figure 1 As shown, the hydraulic system includes a feed cylinder 5, a rotary motor 6, a first multi-way valve 7, and a hydraulic valve group that controls the power head to float axially with the thread. The hydraulic valve group includes two first check valves 8 and two first pressure reducing valves 9. The two first pressure reducing valves 9 are respectively installed in the oil circuits of the first and second cylinders. The two first check valves 8 and the two first pressure reducing valves 9 correspond one-to-one and are arranged in parallel. By setting the first pressure reducing valves 9, the maximum pressure when the feed cylinder 5 floats with the thread can be limited, so as to better protect the threads of the drill pipe and the power head spindle. When the rotary motor 6 rotates the drill pipe thread in the forward direction, high-pressure oil enters the second oil circuit and enters the small chamber 52 of the feed cylinder 5 through the second oil port. The return oil is discharged from the large chamber 51 of the feed cylinder 5 and enters the first cylinder oil circuit and the return oil circuit of the first multi-way valve 7, causing the power head to move axially with the drill pipe, compensating for the thread insertion distance while the power head rotates forward. When the rotary motor 6 reverses and unscrews the connected drill rod thread, high-pressure oil enters the first oil cylinder oil circuit and then enters the large chamber 51 of the feed oil cylinder 5. The return oil is discharged from the small chamber 52 of the feed oil cylinder 5 and enters the second oil circuit and then enters the return oil circuit of the first multi-way valve 7, causing the power head to move axially away from the drill rod. At the same time as the power head reverses, it compensates for the unscrewed thread distance.

[0004] The disadvantage of this hydraulic system is that in each oil line of the feed cylinder 5, the first pressure reducing valve 9 is only set in the oil inlet direction to limit the pressure, while the oil return direction is directly returned through the first check valve 8, that is, the pressure in the oil return chamber is approximately zero. Because the power head's own weight is a unidirectional load with a constant direction (always downward), and the pressure in each chamber is controlled during oil inlet but uncontrolled during oil return, when the pressure supply direction is the same as the gravity direction (when the upper thread is compensated downward), the power head's gravity and the compensation thrust are superimposed, and the axial load acting on the drill pipe thread end face is no less than the power head's own weight. Moreover, this load cannot be reduced or eliminated by adjusting the first pressure reducing valve 9, which can easily cause damage to the thread end face of the thin-walled wireline drill pipe, flattening of the tooth profile, or even mis-threading and seizing. When the pressure supply direction is opposite to the gravity direction (when the uncoupling is compensated upward), the upward force generated by the pressure supply is first passively offset by the self-weight, and the remainder acts on the thread. At this time, the two tasks of offsetting the self-weight and setting the thread pressure are both undertaken by the same pressure parameter (the setting pressure of the pressure reducing valve), and cannot be calibrated independently. As a result, the axial contact pressure acting on the thread cannot be accurately controlled, nor can a small, controllable contact pressure be actively applied on the basis of balancing the self-weight.

[0005] Therefore, there is an urgent need to provide a hydraulic system for engineering geological exploration drilling rigs that allows the power head to independently balance its own weight in both the up-and-down and down-and-down directions, and whose screw thread contact pressure can be calibrated and precisely controlled separately. Summary of the Invention

[0006] (a) Technical problems to be solved In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a hydraulic system for an engineering geological exploration drilling rig, which solves the technical problems of existing drilling rig hydraulic systems being unable to independently balance the self-weight of the power head during threading and unthreading, and the inability to separately calibrate the thread contact pressure, resulting in uncontrollable axial loads on the drill rod threads and easy damage.

[0007] (II) Technical Solution To achieve the above objectives, the main technical solutions adopted by the present invention include: This invention provides a hydraulic system for an engineering geological exploration drilling rig, including an oil tank, a constant pressure pump, a floating valve group, and a feed cylinder; The oil inlet of the constant pressure pump is connected to the oil tank, the oil outlet of the constant pressure pump is connected to the oil inlet of the floating valve group, the oil return port of the floating valve group is connected to the oil tank, and the first working oil port and the second working oil port of the floating valve group are respectively connected to the large chamber and the small chamber of the feed cylinder. The floating valve assembly includes a first pressure reducing valve, a second pressure reducing valve, a first relief valve, and a second relief valve connected in parallel, and the floating valve assembly has three operating states: When the floating valve group is in the off state, the branches containing the first pressure reducing valve, the second pressure reducing valve, the first relief valve, and the second relief valve are all disconnected; When the floating valve group switches to the upper floating state, the branch where the first pressure reducing valve and the first relief valve are located is connected. The hydraulic oil output by the constant pressure pump enters the small chamber through the first pressure reducing valve, and the hydraulic oil in the large chamber flows back to the oil tank through the first relief valve. When the floating valve assembly switches to the shackle floating state, the branch containing the second pressure reducing valve and the second relief valve is connected. The hydraulic oil output by the constant pressure pump enters the large chamber through the second pressure reducing valve, while the hydraulic oil in the small chamber flows back to the oil tank through the second relief valve.

[0008] Optionally, the floating valve assembly also includes a first hydraulically controlled two-position two-way valve connected in series with the first pressure reducing valve, a second hydraulically controlled two-position two-way valve connected in series with the second pressure reducing valve, a fourth hydraulically controlled two-position two-way valve connected in series with the first relief valve, and a third hydraulically controlled two-position two-way valve connected in series with the second relief valve. The first, second, third, and fourth hydraulically controlled two-position two-way valves are normally closed valves, used to selectively open or close the branch they are located in.

[0009] Optionally, the first pressure reducing valve and the first hydraulically controlled two-position two-way valve are connected in series to form an upper pressure oil supply branch. One end of the upper pressure oil supply branch is connected to the oil inlet of the floating valve group, and the other end is connected to the second working oil port. The second pressure reducing valve and the second hydraulic control two-position two-way valve are connected in series to form a shackle oil supply branch. One end of the shackle oil supply branch is connected to the oil inlet of the floating valve group, and the other end is connected to the first working oil port. The first overflow valve and the fourth hydraulically controlled two-position two-way valve are connected in series to form the upper return oil branch. One end of the upper return oil branch is connected to the first working oil port, and the other end is connected to the return oil port of the floating valve group. The second relief valve and the third hydraulically controlled two-position two-way valve are connected in series to form a shackle return oil branch. One end of the shackle return oil branch is connected to the second working oil port, and the other end is connected to the return oil port of the floating valve group.

[0010] Optionally, it may also include an auxiliary valve assembly, which includes a three-position four-way directional valve; The first port of the three-position four-way directional valve is connected to the outlet of the constant pressure pump via the inlet of the auxiliary valve group, and the second port of the three-position four-way directional valve is connected to the oil tank via the return port of the auxiliary valve group. The third port of the three-position four-way directional valve is connected to the first pilot port on the floating valve assembly, and the first pilot port is connected to the control ports of the second hydraulically controlled two-position two-way valve and the third hydraulically controlled two-position two-way valve. The fourth port of the three-position four-way directional valve is connected to the second pilot port on the floating valve assembly, and the second pilot port is connected to the control ports of the first hydraulically controlled two-position two-way valve and the fourth hydraulically controlled two-position two-way valve. The three-position four-way directional valve has three working positions: When the three-position four-way directional valve is in the neutral position, the first, second, third and fourth oil ports of the three-position four-way directional valve are disconnected, so that the floating valve group is in the open state. When the three-position four-way directional valve is switched to the left position, the first oil port of the three-position four-way directional valve is connected to the third oil port, and the second oil port is connected to the fourth oil port, so that the hydraulic oil enters the first pilot oil port of the floating valve group and controls the floating valve group to switch to the unhooking floating state. When the three-position four-way directional valve is switched to the right position, the first oil port of the three-position four-way directional valve is connected to the fourth oil port, and the second oil port is connected to the third oil port, so that the hydraulic oil enters the second pilot oil port of the floating valve group and controls the floating valve group to switch to the upper floating state.

[0011] Optionally, it also includes a load-sensitive pump, a load-sensitive multi-way valve, a rotary motor, and a main winch motor; The oil inlet of the load-sensitive pump is connected to the oil tank, the oil outlet of the load-sensitive pump is connected to the oil inlet of the load-sensitive multi-way valve, the oil return port of the load-sensitive multi-way valve is connected to the oil tank, and the control port of the load-sensitive pump is connected to the load-sensitive port of the load-sensitive multi-way valve. The load-sensitive multi-way valve includes a first working link, a second working link, and a third working link. The first working link is connected to the rotary motor, the second working link is connected to the large and small chambers of the feed cylinder, and the third working link is connected to the main winch motor.

[0012] Optionally, the auxiliary valve assembly also includes a fifth hydraulically controlled two-position two-way valve and a third relief valve; The inlet of the fifth hydraulically controlled two-position two-way valve is connected to the load-sensitive port of the load-sensitive multi-way valve, and the outlet of the fifth hydraulically controlled two-position two-way valve is connected to the inlet of the third relief valve. The outlet of the third relief valve is connected to the oil tank via the return port of the auxiliary valve group. The floating valve assembly has an upper feedback port that is connected to the second pilot port. The upper feedback port is connected to the control port of the fifth hydraulically controlled two-position two-way valve. The fifth hydraulically controlled two-position two-way valve is a normally closed valve. When oil enters the second pilot port, the hydraulic oil enters the fifth hydraulically controlled two-position two-way valve through the upper feedback port, and the branch where the fifth hydraulically controlled two-position two-way valve is opened.

[0013] Optionally, it also includes a pilot handle control valve assembly, and the auxiliary valve assembly also includes a third pressure reducing valve; The oil inlet of the third pressure reducing valve is connected to the oil outlet of the constant pressure pump via the oil inlet of the auxiliary valve group. The oil outlet of the third pressure reducing valve is connected to the oil inlet of the pilot handle control valve group. The oil return port of the pilot handle control valve group is connected to the oil tank. The pilot handle control valve group includes a rotary motor control valve, a feed cylinder control valve, and a main winch control valve connected in parallel. The first working port and the second working port of the rotary motor control valve are respectively connected to the two pilot ports of the first working link to adjust the direction and speed of the rotary motor. The first and second working ports of the feed cylinder control valve are respectively connected to the two pilot ports of the second working link to adjust the direction and speed of the feed cylinder. The first and second working ports of the main winch control valve are respectively connected to the two pilot ports of the third working link to adjust the direction and speed of the main winch motor.

[0014] Optionally, the three-position four-way directional valve is a solenoid directional valve. The two control switches of the three-position four-way directional valve are integrated on the top of the pilot handle control valve group. The two control switches correspond to the on-off floating state and the off-off floating state, respectively.

[0015] Optionally, the slewing motor control valve, the feed cylinder control valve, and the main winch control valve are all proportional pilot handle valves. The pushing direction of the pilot handle of the proportional pilot handle valve determines the reversing direction of the corresponding working link, and the pushing angle of the pilot handle determines the magnitude of the output pilot pressure, which in turn determines the valve core opening degree of the corresponding working link, so as to realize the proportional control of the direction and speed of the slewing motor, the feed cylinder, and the main winch motor.

[0016] Optionally, the feed cylinder is used to drive the power head of the engineering geological exploration drilling rig to move; When the floating valve assembly is in the upper floating state, the set pressure of the first relief valve is configured to form a first back pressure in the large chamber of the feed cylinder. The upward hydraulic pressure generated by the first back pressure acting on the large chamber is equal to the weight of the power head minus the axial upward friction force. The set pressure of the first pressure reducing valve is configured to generate a downward compensating thrust in the small chamber of the feed cylinder to independently set the axial load acting on the drill pipe thread. When the floating valve assembly is in the unhooked floating state, the set pressure of the second pressure reducing valve is configured to generate an upward hydraulic pressure in the large chamber of the feed cylinder. This upward hydraulic pressure is equal to the sum of the self-weight of the power head and the downward axial friction force. The set pressure of the second relief valve is configured to form a second back pressure in the small chamber of the feed cylinder. The set pressure of the second pressure reducing valve can also be gradually increased to drive the power head to move slowly upward.

[0017] (III) Beneficial Effects The beneficial effects of this invention are as follows: The hydraulic system of the engineering geological exploration drilling rig of this invention, by setting a first pressure reducing valve, a second pressure reducing valve, a first relief valve, and a second relief valve in parallel in the floating valve group, allows the floating valve group to supply oil to the small chamber of the feed cylinder through the first pressure reducing valve in the up-lock floating state, while the hydraulic oil in the large chamber flows back to the oil tank through the first relief valve. In the unlock floating state, the second pressure reducing valve supplies oil to the large chamber of the feed cylinder, while the hydraulic oil in the small chamber flows back to the oil tank through the second relief valve. That is, the structure of setting independently adjustable pressure control valves on the oil inlet side and the oil return side of the feed cylinder is superior to the prior art hydraulic system, which only sets a pressure reducing valve on the oil inlet side and the oil return side directly returns to the oil tank through a check valve. This allows the hydraulic system to form back pressure in the large chamber by adjusting the set pressure of the first relief valve during up-locking, thereby balancing the weight of the power head and reducing the axial load acting on the thread end face of the drill rod. The system eliminates the need to add the weight of the power head itself and independently sets the downward compensating thrust by adjusting the set pressure of the first pressure reducing valve. During uncoupling, the system balances the weight of the power head by adjusting the set pressure of the second pressure reducing valve and sets the upward compensating thrust. Simultaneously, the system creates back pressure in the small cavity by adjusting the set pressure of the second overflow valve to improve the rigidity of the floating circuit and stabilize the floating state, ensuring that the operation of other actuators in the system does not interfere with the floating adjustment. Furthermore, when the floating valve group is in the off state, all branches are disconnected, and the power head floating function can be switched on or off as needed without affecting normal drilling operations. As a result, the power head can independently balance its own weight in both the up-coupling and uncoupling directions, and the contact pressure of the drill pipe threads can be calibrated and precisely controlled separately. This effectively avoids drill pipe thread end face damage, tooth profile flattening, or even mis-coupling and seizing, extending the service life of the drill pipe and improving the economic efficiency of construction. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a hydraulic system in the prior art that controls the power head to float along the thread axis. Figure 2 This is a schematic diagram of the hydraulic system of the engineering geological exploration drilling rig of the present invention; Figure 3 for Figure 2 A connection diagram of the load-sensitive pump, load-sensitive multi-way valve, feed cylinder, floating valve group and auxiliary valve group in the process; Figure 4 This is an enlarged schematic diagram of the floating valve assembly and the feed cylinder of the present invention; Figure 5 This is a schematic diagram of the hydraulic oil flow direction of the floating valve assembly of the present invention in the upper floating state; Figure 6 This is a schematic diagram of the hydraulic oil flow direction of the floating valve assembly of the present invention in the unhooked floating state; Figure 7 This is an enlarged schematic diagram of the auxiliary valve assembly and the pilot handle control valve assembly of the present invention; Figure 8 This is an enlarged schematic diagram of the drilling control valve assembly and the main winch motor of the present invention; Figure 9 This is an enlarged schematic diagram of the load-sensitive multi-way valve, main winch motor, and pilot handle control valve assembly of the present invention.

[0019] [Explanation of Labels in the Attached Image] 1: Oil tank; 2: Constant pressure pump; 3: Load-sensitive pump; 4: Load-sensitive multi-way valve; 5: Feed cylinder; 51: Large chamber; 52: Small chamber; 6: Rotary motor; 7: First multi-way valve; 8: First check valve; 9: First pressure reducing valve; 10: Main winch motor; 11: Floating valve assembly; 12: Auxiliary valve assembly; 13: Pilot handle control valve assembly; 14: Drill control valve assembly; 15: Three-position four-way directional valve; 16: First hydraulically controlled two-position two-way valve; 17: Second hydraulically controlled two-position two-way valve; 18: Third hydraulically controlled two-position two-way valve; 19: Fourth hydraulically controlled two-position two-way valve; 20: Second pressure reducing valve ; 21: First relief valve; 22: Second relief valve; 23: Fifth hydraulically controlled two-position two-way valve; 24: Third relief valve; 25: Third pressure reducing valve; 26: Rotary motor control valve; 27: Feed cylinder control valve; 28: Main winch control valve; 29: First two-position three-way directional valve; 30: Sixth pressure reducing valve; 31: Fifth pressure reducing valve; 32: Sixth hydraulically controlled two-position two-way valve; 33: Throttle valve; 34: Double check valve; 35: Brake; 36: Fourth pressure reducing valve; 37: Hydraulically controlled two-position three-way directional valve; 38: First shuttle valve; 39: Second shuttle valve; 40: Two-way balance valve. Detailed Implementation

[0020] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Reference Figures 2 to 9 This embodiment provides a hydraulic system for an engineering geological exploration drilling rig, including an oil tank 1, a constant pressure pump 2, a load-sensitive pump 3, a load-sensitive multi-way valve 4, a feed cylinder 5, a rotary motor 6, a main winch motor 10, a floating valve group 11, an auxiliary valve group 12, a pilot handle control valve group 13, and a drill control valve group 14. The feed cylinder 5 has a large chamber 51 and a small chamber 52, and is connected to the drill rig's power head to drive the power head to move axially along the drill rod. The rotary motor 6 is connected to the power head and drives it to rotate, thereby enabling the threading and unthreading of the drill rod. The main winch motor 10 drives the main winch to raise and lower the drill string.

[0022] like Figure 2 and Figure 3As shown, the hydraulic system in this embodiment is divided into two parts: a main working oil circuit and an auxiliary control oil circuit. In the main working oil circuit, the inlet of the load-sensitive pump 3 is connected to the oil tank 1, the outlet of the load-sensitive pump 3 is connected to the inlet of the load-sensitive multi-way valve 4, the return port of the load-sensitive multi-way valve 4 is connected to the oil tank 1, and the control port of the load-sensitive pump 3 is connected to the load-sensitive port of the load-sensitive multi-way valve 4. The load-sensitive pump 3 supplies flow as needed based on the load pressure feedback from the load-sensitive port. In the auxiliary control oil circuit, the inlet of the constant pressure pump 2 is connected to the oil tank 1, and the outlet of the constant pressure pump 2 is connected to the inlet of the floating valve group 11, the inlet of the auxiliary valve group 12, and the inlet of the drill control valve group 14, respectively, providing a constant pressure oil source for auxiliary functions such as power head floating, main winch floating, and pilot control. The load-sensitive port of the load-sensitive multi-way valve 4 is the LS port. In addition, it should be noted that the load-sensitive pump 3 and the load-sensitive multi-way valve 4 are existing devices. For their working principle and function, please refer to the hydraulic system of a polar drilling rig disclosed in Chinese patent document CN120175306B.

[0023] like Figure 3 and Figure 4 As shown, the first and second working ports of the floating valve assembly 11 are connected to the large chamber 51 and small chamber 52 of the feed cylinder 5, respectively, and the return port of the floating valve assembly 11 is connected to the oil tank 1. The floating valve assembly 11 includes a first pressure reducing valve 9, a second pressure reducing valve 20, a first relief valve 21, and a second relief valve 22 connected in parallel. Further, the floating valve assembly 11 also includes a first hydraulically controlled two-position two-way valve 16 connected in series with the first pressure reducing valve 9, a second hydraulically controlled two-position two-way valve 17 connected in series with the second pressure reducing valve 20, a fourth hydraulically controlled two-position two-way valve 19 connected in series with the first relief valve 21, and a third hydraulically controlled two-position two-way valve 18 connected in series with the second relief valve 22. The first hydraulically controlled two-position two-way valve 16, the second hydraulically controlled two-position two-way valve 17, the third hydraulically controlled two-position two-way valve 18, and the fourth hydraulically controlled two-position two-way valve 19 are all normally closed valves, used to selectively open or close their respective branches. It should be noted that the first working oil port of the floating valve assembly 11 is port A7, and its second working oil port is port B7.

[0024] Specifically, the first pressure reducing valve 9 and the first hydraulically controlled two-position two-way valve 16 are connected in series to form an upper release oil supply branch. One end of the upper release oil supply branch is connected to the oil inlet of the floating valve group 11, and the other end is connected to the second working oil port. The second pressure reducing valve 20 and the second hydraulically controlled two-position two-way valve 17 are connected in series to form an upper release oil supply branch. One end of the upper release oil supply branch is connected to the oil inlet of the floating valve group 11, and the other end is connected to the first working oil port. The first relief valve 21 and the fourth hydraulically controlled two-position two-way valve 19 are connected in series to form an upper release oil return branch. One end of the upper release oil return branch is connected to the first working oil port, and the other end is connected to the return oil port of the floating valve group 11. The second relief valve 22 and the third hydraulically controlled two-position two-way valve 18 are connected in series to form an upper release oil return branch. One end of the upper release oil return branch is connected to the second working oil port, and the other end is connected to the return oil port of the floating valve group 11.

[0025] like Figure 3 and Figure 7 As shown, the auxiliary valve assembly 12 includes a three-position four-way directional valve 15. The first port of the three-position four-way directional valve 15 is connected to the outlet of the constant pressure pump 2 via the inlet of the auxiliary valve assembly 12; the second port of the three-position four-way directional valve 15 is connected to the oil tank 1 via the return port of the auxiliary valve assembly 12; the third port of the three-position four-way directional valve 15 is connected to the first pilot port on the floating valve assembly 11, which is connected to the control ports of the second hydraulically controlled two-position two-way valve 17 and the third hydraulically controlled two-position two-way valve 18; the fourth port of the three-position four-way directional valve 15 is connected to the second pilot port on the floating valve assembly 11, which is connected to the control ports of the first hydraulically controlled two-position two-way valve 16 and the fourth hydraulically controlled two-position two-way valve 19. The first pilot port on the floating valve assembly 11 is port A6, and the second pilot port is port B6.

[0026] The three-position four-way directional valve 15 has three working positions. By switching between the three working positions, the floating valve group 11 is controlled to switch between the open state, the on-off floating state, and the off-off floating state.

[0027] When the three-position four-way directional valve 15 is in the neutral position, the first, second, third, and fourth ports of the three-position four-way directional valve 15 are disconnected. No pressurized oil enters the first and second pilot ports. All four hydraulically controlled two-position two-way valves are normally closed. The branches containing the first pressure reducing valve 9, the second pressure reducing valve 20, the first relief valve 21, and the second relief valve 22 are all disconnected. The floating valve group 11 is in the open state. At this time, the power head floating function is disengaged, the feed cylinder 5 is controlled by the second working link of the load-sensitive multi-way valve 4, and the drilling rig performs normal drilling, feeding, and hoisting operations.

[0028] like Figure 5 As shown, when the three-position four-way directional valve 15 switches to the right position, the first port of the three-position four-way directional valve 15 connects to the fourth port, and the second port connects to the third port. The hydraulic oil output by the constant pressure pump 2 enters the second pilot port of the floating valve group 11, pushing the first hydraulically controlled two-position two-way valve 16 and the fourth hydraulically controlled two-position two-way valve 19 to the open position, while the second hydraulically controlled two-position two-way valve 17 and the third hydraulically controlled two-position two-way valve 18 remain closed, and the floating valve group 11 switches to the upper floating state. At this time, the hydraulic oil output by the constant pressure pump 2 enters the small chamber 52 through the first pressure reducing valve 9 and the first hydraulically controlled two-position two-way valve 16 in sequence, while the hydraulic oil in the large chamber 51 flows back to the oil tank 1 through the fourth hydraulically controlled two-position two-way valve 19 and the first relief valve 21 in sequence. During the forward rotation of the power head, the power head moves downward to compensate for the axial displacement caused by the thread screwing in.

[0029] like Figure 6As shown, when the three-position four-way directional valve 15 switches to the left position, the first port of the three-position four-way directional valve 15 connects to the third port, and the second port connects to the fourth port. The hydraulic oil output by the constant pressure pump 2 enters the first pilot port of the floating valve group 11, pushing the second hydraulically controlled two-position two-way valve 17 and the third hydraulically controlled two-position two-way valve 18 to the open position, while the first hydraulically controlled two-position two-way valve 16 and the fourth hydraulically controlled two-position two-way valve 19 remain closed, and the floating valve group 11 switches to the unscrew floating state. At this time, the hydraulic oil output by the constant pressure pump 2 enters the large chamber 51 through the second pressure reducing valve 20 and the second hydraulically controlled two-position two-way valve 17 in sequence, while the hydraulic oil in the small chamber 52 flows back to the oil tank 1 through the third hydraulically controlled two-position two-way valve 18 and the second relief valve 22 in sequence. During the process of the power head reversing and unscrewing, the power head moves upward to compensate for the axial displacement caused by the screw unscrewing in real time.

[0030] Unlike existing technologies that only install a pressure reducing valve on the oil inlet side and return the oil directly to the oil tank via a check valve on the return side, this embodiment installs independently adjustable pressure reducing valves and overflow valves on the oil inlet and return sides of the oil inlet cylinder 5, respectively, so that the power head can independently balance its own weight in both the up-and-down and down-and-up directions. The following is a detailed explanation in conjunction with the weighing calibration process.

[0031] The weighing calibration process in the upward floating state includes: switching the three-position four-way directional valve 15 to the right position, so that the floating valve group 11 enters the upward floating state; fully loosening the first pressure reducing valve 9, so that its output pressure is approximately zero, that is, the oil supply pressure of the small chamber 52 is zero; at this time, the power head tends to move downward under its own weight, and the hydraulic oil in the large chamber 51 flows back to the oil tank 1 through the fourth hydraulically controlled two-position two-way valve 19 and the first relief valve 21; gradually increasing the set pressure of the first relief valve 21 until the power head stops falling, at this time the upward hydraulic pressure generated by the first back pressure formed by the first relief valve 21 in the large chamber 51 is balanced with the difference between the power head's own weight and the axial upward friction force, thus completing the weighing in the upward direction. On this basis, the output pressure of the first pressure reducing valve 9 is gradually increased, so that the small chamber 52 generates a small downward compensating thrust, and the power head moves down slowly and actively follows the screw thread. Since the weight of the power head and the axial friction force are balanced by the back pressure of the large cavity 51, the axial load acting on the drill pipe thread end face is only the small compensating thrust set by the first pressure reducing valve 9, thus achieving axial protection of the drill pipe thread. It should be noted that because the friction force is upward when the power head moves downward, the upward hydraulic pressure generated by the first back pressure formed by the first overflow valve 21 in the large cavity 51 must be equal to the weight of the power head minus the upward axial friction force, thus achieving weighing balance.

[0032] The weighing calibration process for the shackle floating state includes: switching the three-position four-way directional valve 15 to the left position, causing the floating valve assembly 11 to enter the shackle floating state; fully loosening the second relief valve 22 to prevent back pressure from forming in the small chamber 52; the power head falling under its own weight, while gradually increasing the output pressure of the second pressure reducing valve 20 until the power head stops falling and slowly moves upward. At this point, the hydraulic pressure exerted by the second pressure reducing valve 20 on the large chamber 51 is balanced by the sum of the power head's own weight and axial friction, thus completing the weighing in the shackle direction. Based on this, the set pressure of the second relief valve 22 is adjusted to an appropriate value, such as approximately 2 MPa, to create a second back pressure in the small chamber 52, thereby improving the rigidity of the floating circuit and preventing interference from other actuators in the hydraulic system when they operate; simultaneously, the output pressure of the second pressure reducing valve 20 is appropriately increased to allow the power head to slowly move upward. It should be noted that, because the frictional force is downward when the power head moves upward, the upward hydraulic pressure exerted by the second pressure reducing valve 20 on the large chamber 51 must be equal to the weight of the power head plus the downward axial frictional force in order to achieve weighing balance.

[0033] like Figure 3 As shown, the load-sensitive multi-way valve 4 includes a first working link, a second working link, and a third working link. The first working link is connected to the rotary motor 6, the second working link is connected to the large chamber 51 and the small chamber 52 of the feed cylinder 5, and the third working link is connected to the main winch motor 10. During normal drilling, the floating valve group 11 is in the open state, and the second working link supplies oil to the large chamber 51 and the small chamber 52 of the feed cylinder 5 to realize the feeding and lifting actions; during the top and bottom hook operations, the second working link switches to the neutral position and stops supplying oil to the feed cylinder 5, and the feed cylinder 5 is then independently controlled by the floating valve group 11.

[0034] like Figure 3 and Figure 7 As shown, the auxiliary valve assembly 12 also includes a fifth hydraulically controlled two-position two-way valve 23 and a third relief valve 24. The inlet of the fifth hydraulically controlled two-position two-way valve 23 is connected to the load-sensitive port of the load-sensitive multi-way valve 4, and the outlet of the fifth hydraulically controlled two-position two-way valve 23 is connected to the inlet of the third relief valve 24. The outlet of the third relief valve 24 is connected to the oil tank 1 via the return port of the auxiliary valve assembly 12. The floating valve assembly 11 also has an upper feedback port connected to the second pilot port. The upper feedback port is connected to the control port of the fifth hydraulically controlled two-position two-way valve 23, which is a normally closed valve. The upper feedback port is port MB6.

[0035] When the three-position four-way directional valve 15 switches to the right position (upward floating state), oil enters through the second pilot port. The hydraulic oil enters the control port of the fifth hydraulically controlled two-position two-way valve 23 through the upward feedback port, causing the fifth hydraulically controlled two-position two-way valve 23 to open. The load-sensitive port of the load-sensitive multi-way valve 4 is connected to the oil tank 1 through the third relief valve 24, thereby limiting the maximum output pressure of the load-sensitive pump 3 to the set value of the third relief valve 24, which limits the maximum torque of the rotary motor 6 during upward threading. In this way, if abnormal situations such as misthreading occur during upward threading, the upward threading torque is limited to a safe range to avoid excessive torque damaging the drill pipe threads. When unthreading, the fifth hydraulically controlled two-position two-way valve 23 remains closed, and the torque is not limited, allowing for maximum pressure unthreading and ensuring that engaged or worn threads can be smoothly unthreaded.

[0036] like Figure 7 and Figure 9 As shown, this embodiment also includes a pilot handle control valve assembly 13, and the auxiliary valve assembly 12 further includes a third pressure reducing valve 25. The oil inlet of the third pressure reducing valve 25 is connected to the oil outlet of the constant pressure pump 2 via the oil inlet of the auxiliary valve assembly 12, and the oil outlet of the third pressure reducing valve 25 is connected to the oil inlet of the pilot handle control valve assembly 13. The oil return port of the pilot handle control valve assembly 13 is connected to the oil tank 1. The pilot handle control valve assembly 13 includes a rotary motor control valve 26, a feed cylinder control valve 27, and a main winch control valve 28 connected in parallel. The first and second working ports of the rotary motor control valve 26 are respectively connected to the two pilot ports of the first working link to adjust the direction and speed of the rotary motor 6. The first and second working ports of the feed cylinder control valve 27 are respectively connected to the two pilot ports of the second working link to adjust the direction and speed of the feed cylinder 5. The first and second working ports of the main winch control valve 28 are respectively connected to the two pilot ports of the third working link to adjust the direction and speed of the main winch motor 10. Each control valve is a proportional pilot handle valve. The direction of the handle push determines the reversing direction of the corresponding working link, and the pushing angle of the handle determines the magnitude of the output pilot pressure, which in turn determines the opening degree of the valve core of the corresponding working link, thereby realizing proportional control of the direction and speed of the actuator.

[0037] Preferably, the three-position four-way directional valve 15 is an electromagnetic directional valve, with its two control switches integrated at the top of the pilot handle control valve assembly 13. Specifically, the two control switches are integrated at the top of the pilot handle of the rotary motor control valve 26, corresponding to the engagement and disengagement floating actions, respectively. When engagement or disengagement is required, the operator presses and holds the corresponding switch at the top of the handle with one hand, which corresponds to engagement and disengagement floating respectively. Simultaneously, the operator pushes the handle to rotate the rotary motor 6, thus achieving simultaneous linkage between the power head rotation and floating compensation with a single hand action, greatly simplifying the operation.

[0038] like Figure 8As shown, this embodiment also includes a drill control valve assembly 14, a sixth hydraulically controlled two-position two-way valve 32, and a throttle valve 33. The third working connection is connected to the first working port of the main winch motor 10 via the first oil circuit, and the third working connection is connected to the second working port of the main winch motor 10 via the second oil circuit. One end of the throttle valve 33 is connected to the first oil circuit, and the other end of the throttle valve 33 is connected to the first working port of the sixth hydraulically controlled two-position two-way valve 32. The second working port of the sixth hydraulically controlled two-position two-way valve 32 is connected to the second oil circuit. That is, the throttle valve 33 and the sixth hydraulically controlled two-position two-way valve 32 are connected in series and then bridging the first and second oil circuits.

[0039] The drill control valve assembly 14 includes a first two-position three-way directional valve 29 and a sixth pressure reducing valve 30. The first port of the first two-position three-way directional valve 29 is connected to the outlet of the constant pressure pump 2 via the inlet of the drill control valve assembly 14. The second port of the first two-position three-way directional valve 29 is connected to the oil tank 1 via the return port of the drill control valve assembly 14. The third port of the first two-position three-way directional valve 29 is connected to the inlet of the sixth pressure reducing valve 30. The outlet of the sixth pressure reducing valve 30 is connected to the control port of the sixth hydraulically controlled two-position two-way valve 32, which is a normally closed valve.

[0040] The first two-position three-way directional valve 29 has two working positions: the main winch working position and the main winch floating position. When the first two-position three-way directional valve 29 is in the main winch working position, its second oil port is connected to its third oil port. The oil inlet of the sixth pressure reducing valve 30 is connected to the oil tank 1 through the first two-position three-way directional valve 29. The oil outlet of the sixth pressure reducing valve 30 has no pressure. The sixth hydraulic control two-position two-way valve 32 remains closed. The first oil circuit and the second oil circuit are disconnected. The main winch motor 10 is normally controlled by the third working link to realize the lifting and lowering of the main winch. When the first and second position three-way directional valve 29 is switched to the floating position of the main winch, its first oil port is connected to the third oil port. The hydraulic oil output by the constant pressure pump 2 is reduced by the sixth pressure reducing valve 30 and enters the control oil port of the sixth hydraulic control two-position two-way valve 32. The sixth hydraulic control two-position two-way valve 32 is open, and the first working oil port and the second working oil port of the main winch motor 10 are connected through the throttle valve 33. The two chambers of the motor form an internal circulation, and the main winch motor 10 is in a floating state, realizing the unpowered lowering of the drill bit. Adjusting the opening of the throttle valve 33 can control the flow rate of the internal circulation, thereby controlling the floating lowering speed.

[0041] Furthermore, such as Figure 8 As shown, this embodiment also includes a first shuttle valve 38, a second shuttle valve 39, a fourth pressure reducing valve 36, and a hydraulically controlled two-position three-way directional valve 37.

[0042] The first inlet of the first shuttle valve 38 is connected to the first oil circuit, the second inlet of the first shuttle valve 38 is connected to the second oil circuit, and the outlet of the first shuttle valve 38 is connected to the first inlet of the second shuttle valve 39. The second inlet of the second shuttle valve 39 is connected to the outlet of the sixth pressure reducing valve 30, the outlet of the second shuttle valve 39 is connected to the inlet of the fourth pressure reducing valve 36, the outlet of the fourth pressure reducing valve 36 is connected to the first port of the hydraulically controlled two-position three-way directional valve 37, the second port of the hydraulically controlled two-position three-way directional valve 37 is connected to the oil tank 1, the third port of the hydraulically controlled two-position three-way directional valve 37 is connected to the brake 35 of the main winch motor 10, and the control port of the hydraulically controlled two-position three-way directional valve 37 is connected to the outlet of the fourth pressure reducing valve 36. In other words, the control port and the first port of the hydraulically controlled two-position three-way directional valve 37 are located at the same pressure node, and the hydraulically controlled two-position three-way directional valve 37 directly senses the pressure at the outlet of the fourth pressure reducing valve 36 and switches accordingly. The preset value for switching of the hydraulically controlled two-position three-way directional valve 37 is set to be less than the set pressure of the fourth pressure reducing valve 36, so as to ensure that the oil outlet pressure of the fourth pressure reducing valve 36 can reach the preset value, so that the hydraulically controlled two-position three-way directional valve 37 can switch reliably.

[0043] Both the first shuttle valve 38 and the second shuttle valve 39 employ a shuttle valve structure. Their valve cores move under the pressure difference between the two inlets, always connecting the higher-pressure inlet to the outlet and sealing off the lower-pressure inlet. Thus, the outlet of the first shuttle valve 38 always outputs the higher pressure from the first and second oil circuits, while the outlet of the second shuttle valve 39 always outputs the higher of the motor operating pressure output by the first shuttle valve 38 and the floating control pressure output by the sixth pressure reducing valve 30.

[0044] Under normal tripping conditions, the first and second position three-way directional valve 29 is in the main winch working position. The oil inlet of the sixth pressure reducing valve 30 is connected to the oil tank 1 through the first and second position three-way directional valve 29, and its oil outlet has no pressure. The third working link supplies oil to the first oil circuit or the second oil circuit to drive the main winch motor 10. The first shuttle valve 38 selects the high-pressure oil on the working side of the motor. The second shuttle valve 39 selects the side of the first shuttle valve 38 because there is no pressure on the side of the sixth pressure reducing valve 30, and outputs the motor working pressure to the oil inlet of the fourth pressure reducing valve 36. At this time, the hydraulically controlled two-position three-way directional valve 37 has not yet switched, and its first port is in a closed state. The hydraulic oil is cut off and pressurized at the outlet of the fourth pressure reducing valve 36, and the outlet pressure quickly rises to the set pressure of the fourth pressure reducing valve 36. When this pressure is greater than the preset value, the hydraulically controlled two-position three-way directional valve 37 switches, and its first port connects to the third port. The hydraulic oil from the motor working oil circuit enters the brake 35 after being depressurized by the fourth pressure reducing valve 36. The brake 35 is opened, and the main winch can raise or lower the drilling tools normally. When the third working link stops supplying oil and the motor working oil circuit is depressurized, the outlet pressure of the fourth pressure reducing valve 36 drops to no greater than the preset value. The hydraulically controlled two-position three-way directional valve 37 resets, and its second port connects to the third port. The hydraulic oil inside the brake 35 is quickly discharged into the oil tank 1 through the hydraulically controlled two-position three-way directional valve 37, and the brake 35 is engaged, realizing parking.

[0045] In the floating condition of the main winch, the first two-position three-way directional valve 29 switches to the floating position of the main winch. The hydraulic oil output by the constant pressure pump 2 is depressurized by the sixth pressure reducing valve 30 to establish the floating control pressure. At this time, the two chambers of the main winch motor 10 form an internal circulation through the sixth hydraulic control two-position two-way valve 32 and the throttle valve 33. The pressure of the first oil circuit and the second oil circuit is low. The second shuttle valve 39 selects the side of the sixth pressure reducing valve 30 and outputs the floating control pressure to the oil inlet of the fourth pressure reducing valve 36. The hydraulic oil is also cut off and pressurized at the oil outlet of the fourth pressure reducing valve 36. When the pressure is greater than the preset value, the hydraulic control two-position three-way directional valve 37 switches to open. The hydraulic oil output by the constant pressure pump 2 is depressurized twice through the sixth pressure reducing valve 30, the second shuttle valve 39 and the fourth pressure reducing valve 36 and then enters the brake 35. The brake 35 is opened, allowing the main winch motor 10 to lower the drill string without power in the floating state. After the floating ends, the first two-position three-way directional valve 29 switches back to the main winch working position, the oil inlet of the sixth pressure reducing valve 30 is connected to the oil tank 1, the floating control pressure disappears, the oil outlet pressure of the fourth pressure reducing valve 36 drops to no more than the preset value, the hydraulic control two-position three-way directional valve 37 resets, and the brake 35 releases oil to park.

[0046] Therefore, through the two-stage pressure selection of the first shuttle valve 38 and the second shuttle valve 39, regardless of whether the oil inlet side of the fourth pressure reducing valve 36 is connected to the motor working pressure (during normal drilling and hoisting) or the floating control pressure (when the main winch is floating), the higher pressure of the two is reduced by the fourth pressure reducing valve 36 and established at its oil outlet, and acts on the control oil port of the hydraulic two-position three-way reversing valve 37, so that the brake 35 can automatically open as the pressure is established and automatically engage as the pressure is lost under both working conditions, realizing the automatic control of brake 35 release and parking, without the need to set up a separate control oil circuit for the brake 35. Meanwhile, since the control port of the hydraulic two-position three-way directional valve 37 senses the outlet pressure of the fourth pressure reducing valve 36, and its first port is connected to the third port only when the pressure is greater than the preset value, the hydraulic two-position three-way directional valve 37 is functionally equivalent to a sequence valve set upstream of the brake 35: first, sufficient pressure is established at the outlet, and then the brake oil circuit is connected, which avoids the brake 35 from being opened accidentally when the pressure is insufficient, and improves the safety of drilling and floating lowering operations.

[0047] Furthermore, such as Figure 8 As shown, this embodiment also includes a bidirectional balance valve 40, which is connected in series in the first oil circuit and the second oil circuit between the third working link and the main winch motor 10, to balance the weight of the drill bit, limit the lowering speed and maintain the load on the drill bit.

[0048] During normal hoisting of the drill string, the pressurized oil output from the third working link opens the check valve on the corresponding side of the bidirectional balance valve 40 via the first oil circuit (or the second oil circuit), entering one chamber of the main winch motor 10 and driving the main winch motor 10 to rotate and lift the drill string. The return oil flows back to the oil tank 1 via the other oil circuit through the bidirectional balance valve 40. During normal lowering of the drill string, the drill string's own weight drives the main winch motor 10 via the drum, causing it to rotate faster and faster. The bidirectional balance valve 40 forms a back pressure on the motor's return oil side that matches the load, balancing the drill string's own weight and limiting the lowering speed, ensuring a smooth lowering of the drill string without stalling. When the third working link switches to the neutral position or the hydraulic system stops supplying oil, the bidirectional balance valve 40 closes the oil circuits of both chambers of the main winch motor 10, maintaining the load on the drill string. Together with the brake 35, it forms a dual mechanical and hydraulic protection system to prevent the drill string from accidentally falling due to its own weight.

[0049] It should be noted that the internal circulating oil circuit formed by the two chambers of the main winch motor 10 via the throttle valve 33 and the sixth hydraulically controlled two-way valve 32 is located on the motor side of the bidirectional balance valve 40 and does not pass through the bidirectional balance valve 40. Therefore, the floating and lowering speed of the main winch is controlled only by the opening degree of the throttle valve 33 and is not affected by the bidirectional balance valve 40. The branch where the first shuttle valve 38 is located is located on the multi-way valve side of the bidirectional balance valve 40.

[0050] Furthermore, such as Figure 8As shown, this embodiment also includes a double check valve 34, and the drill control valve group 14 also includes a fifth pressure reducing valve 31. The third oil port of the first two-position three-way directional valve 29 is also connected to the oil inlet of the fifth pressure reducing valve 31, the oil outlet of the fifth pressure reducing valve 31 is connected to the oil inlet of the double check valve 34, the first oil outlet of the double check valve 34 is connected to the first oil circuit, and the second oil outlet of the double check valve 34 is connected to the second oil circuit. When the main winch motor 10 floats, its two chambers circulate internally. Due to internal leakage in the motor, the circulating oil will be insufficient. The hydraulic oil output by the constant pressure pump 2 enters the double check valve 34 after being reduced by the fifth pressure reducing valve 31. The double check valve 34 automatically directs the replenishment oil to the side with lower pressure (i.e., the side that serves as the suction chamber) according to the pressure difference between the first oil circuit and the second oil circuit, to compensate for the insufficient oil caused by the internal leakage of the motor and prevent the main winch motor 10 from sucking in air.

[0051] It should be noted that the double check valve 34 can be composed of two check valves. The inlets of the two check valves are interconnected, forming the inlet of the double check valve 34. The outlets of the two check valves form the first outlet and the second outlet of the double check valve 34, respectively. Therefore, the replenishing oil from the fifth pressure reducing valve 31 can only flow from the inlet to either the first or second outlet. When the pressure on one side of the first or second oil circuit is higher, the check valve on that side remains closed under the pressure of that side, and the replenishing oil automatically flows to the side with lower pressure, thus achieving the function of automatically selecting the replenishing direction. The replenishing branch of the double check valve 34 is located on the motor side of the bidirectional balance valve 40, so that the replenishing oil can be directly replenished into the two chambers of the main winch motor 10 without passing through the bidirectional balance valve 40.

[0052] like Figure 9 As shown, in this embodiment, the main winch motor 10 is a variable displacement motor. The main winch control valve 28 also has a third working port connected in parallel with the first and second working ports, and the third working port is connected to the control port of the variable displacement motor. The main winch control valve 28 adopts a pressure-section coupling design, having a first pressure adjustment section and a second pressure adjustment section larger than the first pressure adjustment section. In the first pressure adjustment section, the pilot pressure output by the main winch control valve 28 acts on the two pilot ports of the third working section, and the speed of the main winch motor 10 is controlled by adjusting the valve core opening degree of the third working section. At this time, the variable displacement motor maintains a large displacement. When the pilot pressure reaches the second pressure adjustment section, the valve core opening degree of the third working section has reached its maximum. The pilot pressure acts on the control port of the variable displacement motor through the third working port, and the displacement is reduced by adjusting the swashplate angle of the variable displacement motor, thereby further increasing the speed of the main winch motor 10.

[0053] For example, the pilot pressure range of the main winch control valve 28 is 5-25 bar, with the first pressure adjustment range being 7.5-18 bar and the second pressure adjustment range being 18-25 bar. Within the 5-7.5 bar pilot pressure range, the valve core of the third working link is not yet open; this range is equivalent to the dead zone of the pilot handle, preventing malfunctions when the handle is near the neutral position. Within the first pressure adjustment range, the valve core opening of the third working link increases proportionally with the increase in pilot pressure, and the speed of the main winch motor 10 increases accordingly. Furthermore, since the variable displacement motor only begins to decrease its displacement after the pilot pressure reaches 18 bar (i.e., the initial pressure of the variable displacement is 18 bar), the variable displacement motor maintains its maximum displacement within the first pressure adjustment range. When the pilot pressure enters the second pressure adjustment range, the valve core opening of the third working link has reached its maximum and remains constant; the displacement of the variable displacement motor decreases with the increase in pilot pressure, and the speed of the main winch motor 10 further increases. Thus, within the controllable pressure range of a single pilot handle, the coupling of two speed regulation methods—the opening degree control of the third working valve core and the displacement control of the variable motor—is achieved, significantly widening the speed regulation range of the main winch. Combined with the on-demand oil supply characteristic of the load-sensitive pump 3, the main winch can achieve wide and precise speed regulation. It should be noted that the pressure values ​​mentioned above are merely examples; specific values ​​can be set according to the model of the main winch motor 10 and the speed regulation requirements.

[0054] With the above structure, the hydraulic system of the engineering geological exploration drilling rig in this embodiment has at least the following beneficial effects: the power head can independently balance its own weight in both the up-and-down and down-and-down directions; the contact pressure of the drill rod thread can be calibrated and precisely controlled separately, effectively avoiding damage to the drill rod thread end face, flattening of the tooth profile, or even mis-threading and seizing, thus extending the service life of the drill rod; the up-and-down torque is limited, protecting the drill rod thread; the main winch can achieve unpowered floating descent, automatic brake release and parking, and wide-range speed adjustment, making operation simple, safe, and reliable.

[0055] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0056] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A hydraulic system for an engineering geological exploration drilling rig, characterized in that, It includes an oil tank (1), a constant pressure pump (2), a floating valve group (11), and a feed cylinder (5); The oil inlet of the constant pressure pump (2) is connected to the oil tank (1), the oil outlet of the constant pressure pump (2) is connected to the oil inlet of the floating valve group (11), the oil return port of the floating valve group (11) is connected to the oil tank (1), and the first working oil port and the second working oil port of the floating valve group (11) are respectively connected to the large chamber (51) and the small chamber (52) of the oil inlet cylinder (5). The floating valve assembly (11) includes a first pressure reducing valve (9), a second pressure reducing valve (20), a first relief valve (21), and a second relief valve (22) connected in parallel, and the floating valve assembly (11) has three operating states: When the floating valve group (11) is in the open state, the branches containing the first pressure reducing valve (9), the second pressure reducing valve (20), the first relief valve (21), and the second relief valve (22) are all disconnected; When the floating valve group (11) switches to the upper floating state, the branch where the first pressure reducing valve (9) and the first relief valve (21) are located is connected. The hydraulic oil output by the constant pressure pump (2) enters the small chamber (52) through the first pressure reducing valve (9), and the hydraulic oil in the large chamber (51) flows back to the oil tank (1) through the first relief valve (21). When the floating valve group (11) switches to the shackle floating state, the branch where the second pressure reducing valve (20) and the second relief valve (22) are located is connected. The hydraulic oil output by the constant pressure pump (2) enters the large chamber (51) through the second pressure reducing valve (20), and the hydraulic oil in the small chamber (52) flows back to the oil tank (1) through the second relief valve (22).

2. The hydraulic system of the engineering geological exploration drilling rig as described in claim 1, characterized in that, The floating valve assembly (11) also includes a first hydraulically controlled two-position two-way valve (16) connected in series with the first pressure reducing valve (9), a second hydraulically controlled two-position two-way valve (17) connected in series with the second pressure reducing valve (20), a fourth hydraulically controlled two-position two-way valve (19) connected in series with the first relief valve (21), and a third hydraulically controlled two-position two-way valve (18) connected in series with the second relief valve (22). The first hydraulically controlled two-position two-way valve (16), the second hydraulically controlled two-position two-way valve (17), the third hydraulically controlled two-position two-way valve (18), and the fourth hydraulically controlled two-position two-way valve (19) are normally closed valves, used to selectively open or close the branch they are located in.

3. The hydraulic system of the engineering geological exploration drilling rig as described in claim 2, characterized in that, The first pressure reducing valve (9) and the first hydraulic control two-position two-way valve (16) are connected in series to form an upper pressure oil supply branch. One end of the upper pressure oil supply branch is connected to the oil inlet of the floating valve group (11), and the other end is connected to the second working oil port. The second pressure reducing valve (20) and the second hydraulic control two-position two-way valve (17) are connected in series to form a shackle oil supply branch. One end of the shackle oil supply branch is connected to the oil inlet of the floating valve group (11), and the other end is connected to the first working oil port. The first overflow valve (21) and the fourth hydraulic control two-position two-way valve (19) are connected in series to form an upper return oil branch. One end of the upper return oil branch is connected to the first working oil port, and the other end is connected to the return oil port of the floating valve group (11). The second relief valve (22) and the third hydraulic control two-position two-way valve (18) are connected in series to form a shackle return oil branch. One end of the shackle return oil branch is connected to the second working oil port, and the other end is connected to the return oil port of the floating valve group (11).

4. The hydraulic system of the engineering geological exploration drilling rig as described in claim 2, characterized in that, It also includes an auxiliary valve assembly (12), which includes a three-position four-way directional valve (15). The first oil port of the three-position four-way directional valve (15) is connected to the oil outlet of the constant pressure pump (2) through the oil inlet of the auxiliary valve group (12), and the second oil port of the three-position four-way directional valve (15) is connected to the oil tank (1) through the oil return port of the auxiliary valve group (12). The third port of the three-position four-way directional valve (15) is connected to the first pilot port on the floating valve group (11), and the first pilot port is connected to the control ports of the second hydraulically controlled two-position two-way valve (17) and the third hydraulically controlled two-position two-way valve (18). The fourth port of the three-position four-way directional valve (15) is connected to the second pilot port on the floating valve group (11), and the second pilot port is connected to the control ports of the first hydraulically controlled two-position two-way valve (16) and the fourth hydraulically controlled two-position two-way valve (19). The three-position four-way directional valve (15) has three working positions: When the three-position four-way directional valve (15) is in the neutral position, the first port, the second port, the third port and the fourth port of the three-position four-way directional valve (15) are disconnected so that the floating valve group (11) is in the open state. When the three-position four-way directional valve (15) is switched to the left position, the first oil port of the three-position four-way directional valve (15) is connected to the third oil port, and the second oil port is connected to the fourth oil port, so that the hydraulic oil enters the first pilot oil port of the floating valve group (11) and controls the floating valve group (11) to switch to the unhooking floating state. When the three-position four-way directional valve (15) is switched to the right position, the first oil port of the three-position four-way directional valve (15) is connected to the fourth oil port, and the second oil port is connected to the third oil port, so that the hydraulic oil enters the second pilot oil port of the floating valve group (11) and controls the floating valve group (11) to switch to the upper floating state.

5. The hydraulic system of the engineering geological exploration drilling rig as described in claim 4, characterized in that, It also includes a load-sensitive pump (3), a load-sensitive multi-way valve (4), a rotary motor (6), and a main winch motor (10). The oil inlet of the load-sensitive pump (3) is connected to the oil tank (1), the oil outlet of the load-sensitive pump (3) is connected to the oil inlet of the load-sensitive multi-way valve (4), the oil return port of the load-sensitive multi-way valve (4) is connected to the oil tank (1), and the control port of the load-sensitive pump (3) is connected to the load-sensitive port of the load-sensitive multi-way valve (4). The load-sensitive multi-way valve (4) includes a first working link, a second working link and a third working link. The first working link is connected to the rotary motor (6), the second working link is connected to the large chamber (51) and the small chamber (52) of the feed cylinder (5), and the third working link is connected to the main winch motor (10).

6. The hydraulic system of the engineering geological exploration drilling rig as described in claim 5, characterized in that, The auxiliary valve assembly (12) also includes a fifth hydraulically controlled two-position two-way valve (23) and a third relief valve (24). The inlet of the fifth hydraulic control two-position two-way valve (23) is connected to the load-sensitive port of the load-sensitive multi-way valve (4), and the outlet of the fifth hydraulic control two-position two-way valve (23) is connected to the inlet of the third relief valve (24). The outlet of the third relief valve (24) is connected to the oil tank (1) via the return port of the auxiliary valve group (12). The floating valve assembly (11) has an upper feedback port that is connected to the second pilot port. The upper feedback port is connected to the control port of the fifth hydraulic control two-position two-way valve (23). The fifth hydraulic control two-position two-way valve (23) is a normally closed valve. When oil enters the second pilot port, the hydraulic oil enters the fifth hydraulic control two-position two-way valve (23) through the upper feedback port, and the branch where the fifth hydraulic control two-position two-way valve (23) is opened.

7. The hydraulic system of the engineering geological exploration drilling rig as described in claim 5 or 6, characterized in that, It also includes a pilot handle control valve assembly (13), and the auxiliary valve assembly (12) also includes a third pressure reducing valve (25); The oil inlet of the third pressure reducing valve (25) is connected to the oil outlet of the constant pressure pump (2) via the oil inlet of the auxiliary valve group (12). The oil outlet of the third pressure reducing valve (25) is connected to the oil inlet of the pilot handle control valve group (13). The oil return port of the pilot handle control valve group (13) is connected to the oil tank (1). The pilot handle control valve group (13) includes a rotary motor control valve (26), a feed cylinder control valve (27), and a main winch control valve (28) connected in parallel. The first working port and the second working port of the rotary motor control valve (26) are respectively connected to the two pilot ports of the first working link to adjust the direction and speed of the rotary motor (6); The first working port and the second working port of the feed cylinder control valve (27) are respectively connected to the two pilot ports of the second working link to adjust the direction and speed of the feed cylinder (5); The first working port and the second working port of the main winch control valve (28) are respectively connected to the two pilot ports of the third working link to adjust the direction and speed of the main winch motor (10).

8. The hydraulic system of the engineering geological exploration drilling rig as described in claim 7, characterized in that, The three-position four-way directional valve (15) is an electromagnetic directional valve. The two control switches of the three-position four-way directional valve (15) are integrated on the top of the pilot handle control valve group (13). The two control switches correspond to the on-off floating state and the off-off floating state, respectively.

9. The hydraulic system of the engineering geological exploration drilling rig as described in claim 7, characterized in that, The rotary motor control valve (26), the feed cylinder control valve (27), and the main winch control valve (28) are all proportional pilot handle valves. The pushing direction of the pilot handle of the proportional pilot handle valve determines the reversing direction of the corresponding working link, and the pushing angle of the pilot handle determines the magnitude of the output pilot pressure, which in turn determines the valve core opening degree of the corresponding working link, so as to realize the proportional control of the action direction and speed of the rotary motor (6), the feed cylinder (5), and the main winch motor (10).

10. The hydraulic system of the engineering geological exploration drilling rig as described in claim 1, characterized in that, The feed cylinder (5) is used to drive the power head of the engineering geological exploration drilling rig to move; When the floating valve assembly (11) is in the upper floating state, the setting pressure of the first relief valve (21) is configured to form a first back pressure in the large chamber (51) of the feed cylinder (5). The upward hydraulic pressure generated by the first back pressure acting on the large chamber (51) is equal to the weight of the power head minus the axial upward friction force. The setting pressure of the first pressure reducing valve (9) is configured to generate a downward compensating thrust in the small chamber (52) of the feed cylinder (5) to independently set the axial load acting on the drill pipe thread. When the floating valve assembly (11) is in the unhooked floating state, the set pressure of the second pressure reducing valve (20) is configured to generate an upward hydraulic pressure in the large chamber (51) of the feed cylinder (5). This upward hydraulic pressure is equal to the sum of the self-weight of the power head and the downward axial friction force. The set pressure of the second relief valve (22) is configured to form a second back pressure in the small chamber (52) of the feed cylinder (5). The set pressure of the second pressure reducing valve (20) can also be gradually increased to drive the power head to move slowly upward.

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