The YCJF-20 full hydraulic percussion reverse circulation drilling rig is a large-diameter full hydraulic percussion reverse circulation drilling rig developed by our factory, mainly suitable for large-diameter bored cast-in-place pile construction in deep foundation engineering.

I. Features of YCJF-20 Full Hydraulic Percussion Reverse Circulation Drilling Rig:

1. The drilling rig adopts full hydraulic transmission and a unique hydraulic cylinder percussion method, featuring stable transmission, low noise, low power consumption, and good overload protection.

2. The drilling rig realizes the integration of mechanical, hydraulic, and electrical systems. Automatic percussion and automatic feeding are controlled by a single-chip microcomputer, making operation centralized, convenient, labor-saving, safe, and reliable. Automatic and manual percussion modes can be selected at will, and the percussion stroke and frequency can be adjusted steplessly or in steps, adapting to the construction requirements of various strata.

3. The drilling rig has an automatic rope release feeding function. During percussion, according to the drilling progress of the percussion bit, the rope can be automatically released at the right time and in the right amount, fully utilizing the impact energy of the bit, avoiding idle hammering, and effectively improving drilling efficiency. Manual rope release can also be selected for flexible control of percussion feeding.

4. The drilling rig has a unique percussion method, achieving smooth lifting and free fall of the drill bit. The drill bit has large mass and high impact energy, suitable for large-diameter construction. Main working components such as wire ropes and springs have long service lives, and the rig has few wearing parts, resulting in low usage costs.

5. The drilling rig is equipped with hydraulic walking mechanisms, allowing convenient movement on the construction site. The hydraulic walking mechanisms are mounted on the rig chassis and are transported together with the rig without disassembly.

6. The raising and lowering of the drilling mast are hydraulically controlled, ensuring stability, safety, and convenient operation.

II. Structure of YCJF-20 Full Hydraulic Percussion Reverse Circulation Drilling Rig

1. Hydraulic Power Station

The hydraulic power station mainly consists of an electric motor, main and auxiliary hydraulic pumps, oil tank, cooler, electrical control cabinet, etc. The main pump is an inclined-axis variable displacement piston pump, supplying pressure oil to the percussion mechanism and the main winch. The oil tank is equipped with a return oil filter and a suction oil filter to filter impurities in the hydraulic oil. The cooler is used to reduce the temperature of the hydraulic oil.

2. Operation Console

The operation console mainly consists of an electrical control box and hydraulic valves. The electrical control box mainly controls the start and stop of the main pump, auxiliary pump, cooler, and tool winch; switches between manual and automatic percussion, manual and automatic rope release, and increase and decrease of auxiliary pump pressure; in automatic percussion mode, the single-chip microcomputer automatically controls the reversing of the percussion cylinder; in automatic rope release mode, the single-chip microcomputer automatically controls the main winch to release the rope at the right time and in the right amount; the hydraulic proportional pilot valve in the middle of the console is used to control the forward rotation, reverse rotation, and stop of the main winch and the braking of the main and auxiliary winches; the hydraulic directional valve on the right is used for manual control of the reversing of the percussion cylinder; the hydraulic directional valve on the left is used to control the forward rotation, reverse rotation, and stop of the auxiliary winch; the pressure reducing valve handwheel on the lower left is used to control the displacement of the main pump, which can change the rotation speed of the main winch or the percussion frequency of the percussion cylinder; the pressure gauge on the console displays the working pressure of the main pump (when the main pump is unloaded and the auxiliary pump is working, it displays the auxiliary pump pressure) and the working pressure of the pilot valve.

3. Main Winch

The main winch mainly consists of a hydraulic motor, reducer, winch, and braking device. The winch is a double-drum type with a differential device, used to adjust the tension balance of the two percussion wire ropes and to lift the drill bit. The hydraulic motor can rotate forward and reverse, supplied with oil by the main pump and auxiliary pump respectively. The main pump supplies oil for lifting or lowering the drill bit by the main winch, with stepless speed adjustment. The auxiliary pump supplies oil for feeding and releasing or retracting the rope by the main winch, at a constant speed.

4. Hydraulic Cylinder Percussion Mechanism

The hydraulic cylinder percussion mechanism mainly consists of a percussion cylinder and a percussion wheel assembly. The percussion cylinder is a specially designed cylinder that lifts and lowers the drill bit through the percussion wheel assembly and wire rope to achieve percussion drilling. The percussion wheel assembly not only transmits the pulling force of the cylinder to the wire rope but also serves as a guide during up and down movement.

5. Drilling Mast

The drilling mast mainly consists of a mast raising cylinder, base, mast body, mast beam, buffer device, crown block, etc. The mast can be erected and laid flat by the mast raising cylinder, putting the rig in working or transport state. The buffer device is mainly used to absorb the percussion vibration of the percussion wheel assembly and to guide the percussion wire rope. The crown block is used for the auxiliary winch and tool winch.

6. Hydraulic Walking Mechanism

The hydraulic walking mechanism enables the rig to move short distances on the same site and facilitates alignment with the hole position. The hydraulic walking mechanism mainly consists of iron tracks, cross beams, roller assemblies, cylinders, and hydraulic control valves. By operating the control valve, the movement of the cylinders can be controlled, enabling the rig to move up and down, forward and backward, and left and right.

7. Chassis

The chassis is mainly used to install and connect the various components of the rig. The wellhead device is mainly a working platform for installing and removing the slag discharge pipe.

8. Auxiliary Winch

The auxiliary winch is mainly used for lifting or lowering the slag discharge pipe. This winch has a fast lowering function. When the percussion bit is stuck in the hole, the auxiliary winch can be used to lift the percussion hammer to impact and vibrate the stuck bit, solving the problem of stuck drilling.

9. Tool Winch The tool winch is used for lifting supporting drilling tools and tools on the construction site.

In addition to the above components, the drilling rig is also equipped with a percussion hammer, slag discharge pipe, 6BS sand-gravel pump for reverse circulation drilling, 3PNL mud pump, and mud pipelines, etc.