MAIN HOIST SYSTEM OF ROTARY DRILLING RIG, AND CONTROL METHOD THEREFOR

Abstract

A main winch system of a rotary drilling rig includes a main action loop, a pilot control loop, and a feedback control loop. The main action loop includes an engine, a hydraulic pump, a main control valve, a balance valve, a main winch motor, and an oil tank. The pilot control loop includes a pilot handle, a solenoid valve I, a pressure relay, and the main control valve in the main action loop. The feedback control loop includes a solenoid valve II and the hydraulic pump and the main control valve in the main action loop. In response to a lifting action of the pilot handle for the main winch, under the control of a button, the solenoid valve II is energized continuously, and the solenoid valve I is energized and de-energized according to a given rule.

Claims

1. A main winch system of a rotary drilling rig, comprising a main action loop, a pilot control loop, and a feedback control loop, wherein the main action loop comprises an engine, a hydraulic pump, a main control valve, a balance valve, a main winch motor, and an oil tank; the pilot control loop comprises a pilot handle, a solenoid valve, a pressure relay, and the main control valve in the main action loop; and the feedback control loop comprises a connecting solenoid valve and the hydraulic pump and the main control valve in the main action loop.

2. The main winch system according to claim 1, wherein an oil supply port P1 of the hydraulic pump is connected to a port P of the main control valve; a port A and a port B of the main control valve are connected to an oil inlet of the balance valve; an oil outlet of the balance valve is connected to an oil inlet and an oil outlet of the main winch motor; and a port T of the main control valve is connected to the oil tank.

3. The main winch system according to claim 1, wherein the solenoid valve comprises an oil inlet connected to a lifting port of the pilot handle, an oil outlet connected to a lifting pilot port Xb1 of the main control valve, and an oil return port connected to the oil tank; a lowering port of the pilot handle is connected to a lowering pilot port Xa1 of the main control valve; and the pressure relay is connected to the lifting port of the pilot handle.

4. The main winch system according to claim 1, wherein the connecting solenoid valve comprises an oil inlet connected to a feedback port N1 of the main control valve, an oil outlet connected to a feedback port Pi of the hydraulic pump, and an oil return port connected to the oil tank.

5. The main winch system according to claim 1, wherein both the solenoid valve and the connecting solenoid valve are a two-position three-way solenoid valve.

6. A control method of the main winch system of a rotary drilling rig according to claim 1, comprising the following steps: a: reversing the pilot handle to a lifting shift, and controlling, through a button, energization and de-energization of the solenoid valve in a cycle; and b: energizing the connecting solenoid valve continuously to maintain the hydraulic pump at a maximum displacement state.

7. The control method according to claim 6, wherein in step a, when the pilot handle is reversed to the lifting shift, if the solenoid valve is de-energized, the main control valve is opened, and the hydraulic pump supplies oil to the main winch motor; and if the solenoid valve is energized, the main control valve is closed, and a lifting action for a main winch is stopped.

8. The control method according to claim 6, wherein in step b, when the main control valve is closed and the connecting solenoid valve is energized continuously, the feedback port Pi of the hydraulic pump communicates with the oil tank, a feedback pressure is lowered, and the hydraulic pump is maintained at the maximum displacement state.

9. The control method according to claim 6, wherein in step a, the solenoid valve is energized and de-energized once in each cycle, and energization time and de-energization time are different.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIGURE is an overall schematic structural view of the present disclosure

[0021] In the FIGURE: 1: engine, 2: hydraulic pump, 3: oil tank, 4: main control valve, 5: balance valve, 6: main winch motor, 7: pilot handle, 8: solenoid valve I, 9: solenoid valve II, and 10: pressure relay.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] As shown in the FIGURE, a main winch system of a rotary drilling rig includes a main action loop, a pilot control loop, and a feedback control loop. The main action loop includes engine 1, hydraulic pump 2, main control valve 4, balance valve 5, main winch motor 6, and oil tank 3. The pilot control loop includes pilot handle 7, solenoid valve I 8, pressure relay 10, and the main control valve 4 in the main action loop. The feedback control loop includes connecting solenoid valve II 9 and the hydraulic pump 2 and the main control valve 4 in the main action loop. Both the solenoid valve I 8 and the solenoid valve II 9 are two-position three-way solenoid valves. The present disclosure controls the solenoid valve I 8 through a button, thereby shaking the main winch up and down automatically. The main winch is responsive in action and can shake off the cohesive soil on the drilling tool easily without manual operation. Therefore, the main winch system of a rotary drilling rig reduces the reliance on an operator and improves construction efficiency.

[0023] Oil supply port P1 of the hydraulic pump 2 is connected to port P of the main control valve 4. Port A and port B of the main control valve 4 are connected to an oil inlet of the balance valve 5. An oil outlet of the balance valve 5 is connected to an oil inlet and an oil outlet of the main winch motor 6. Port T of the main control valve 4 is connected to the oil tank 3. Therefore, the main action loop is formed.

[0024] The solenoid valve I 8 includes an oil inlet connected to a lifting port of the pilot handle 7, an oil outlet connected to lifting pilot port Xb1 of the main control valve 4, and an oil return port connected to the oil tank 3. A lowering port of the pilot handle 7 is connected to lowering pilot port Xa1 of the main control valve 4. The pressure relay 10 is connected to the lifting port of the pilot handle 7 and configured to detect a lifting action. Therefore, the pilot control loop is formed.

[0025] The solenoid valve II 9 includes an oil inlet connected to feedback port N1 of the main control valve 4, an oil outlet connected to feedback port Pi of the hydraulic pump 2, and an oil return port connected to the oil tank 3. Therefore, the feedback control loop is formed.

[0026] A control method for the main winch system of a rotary drilling rig includes the following steps: [0027] a: The pilot handle 7 is reversed to a lifting shift. Energization and de-energization of the solenoid valve I 8 in a cycle are controlled through a button. In each cycle, the solenoid valve I 8 is energized and de-energized once. Energization time and de-energization time have different values. [0028] b: The solenoid valve II 9 is energized continuously, such that the hydraulic pump 2 is maintained at a maximum displacement state all the time.

[0029] In Step a, when the pilot handle 7 is reversed to the lifting shift, if the solenoid valve I 8 is de-energized, the lifting port of the pilot handle 7 communicates with the lifting pilot port Xb1 of the main control valve 4, the main control valve 4 is opened, and the hydraulic pump 2 supplies oil to the main winch motor 6. If the solenoid valve I 8 is energized, the lifting pilot port Xb1 of the main control valve 4 communicates with the oil tank 3, the main control valve 4 is closed, and the lifting action for the main winch is stopped.

[0030] In Step b, when the main control valve 4 is closed, if the solenoid valve II 9 is de-energized, the feedback port N1 of the main control valve 4 communicates with the feedback port Pi of the hydraulic pump, a feedback pressure is applied to the feedback port Pi of the hydraulic pump 2, and the hydraulic pump 2 is maintained at a minimum displacement state. If the solenoid valve II 9 is energized, the feedback port Pi of the hydraulic pump 2 communicates with the oil tank 3, the feedback pressure is lowered, and the hydraulic pump 2 is maintained at the maximum displacement state.

[0031] In response to the lifting action of the pilot handle for the main winch, the two-position three-way solenoid valve 8 is energized and de-energized according to a given rule under the control of the button. Therefore, the pilot oil passage in a lifting direction is connected and disconnected continuously, the main winch is lifted and stopped repeatedly, and a drilling tool suspended on the main winch shakes up and down according to a certain rule, thereby shaking off the cohesive soil on the drilling tool easily to achieve a soil shaking effect. During the soil shaking process, the solenoid valve 9 is energized continuously, such that the hydraulic pump 2 is maintained at the maximum displacement state. If the main control valve 4 is opened and closed repeatedly in the soil shaking process, both the feedback pressure and the displacement of the hydraulic pump 2 change correspondingly, such that the action response speed of the main winch is affected to achieve the dissatisfactory soil shaking effect.