Dynamic Pressure Feedback Pilot Control Hydraulic Shock Oscillator

Abstract

The invention discloses a dynamic pressure feedback pilot control hydraulic impact oscillator, which adopts a jet element as a pilot stage, and the jet element and a reversing valve form a two-stage combined control, and the high pressure water or high pressure oil carries hydraulic energy to drive the piston high. Shock oscillation device with frequent reciprocating motion. After the total flow is input, it is dynamically distributed to the jet element and the reversing valve. The flow provided to the jet element only needs to meet the requirements of driving the main spool reversing. Most of the flow is controlled by the reversing valve and provided to the impact mechanism. In addition, the device uses the water hammer pressure signal of the internal feedback mechanism to control the switching of the attached wall jet, and then pushes the main valve core to change direction, realizing the high-frequency reciprocating motion of the piston of the impact mechanism under the condition of large flow rate, resulting in high-energy impact oscillation . The device can be used as a core component, widely used in rotary drilling tool systems for deep well hard rock drilling, and can also be used to build hydraulic breakers, top drive hydraulic pile hammers or pipe rammers, and hydraulic vibration test benches.

Description

technical field [0001] The invention relates to a hydraulic shock and vibration device, in particular to a dynamic pressure feedback pilot control hydraulic shock oscillator. Background technique [0002] The proposal of the hydraulic jet impactor can be traced back to the Chinese invention patent CN2040529 in 1989. This patent discloses a hydraulic impact vibration device that uses a bistable wall-attached jet element to directly drive the piston to do work. Due to the simple structure of the whole machine, It is easy to manufacture and adopts clear water and mud as the working medium and is compatible with the drilling process. This type of product is widely used in the fields of geological exploration and oil and gas well exploration and drilling. During the specific use of the hydraulic jet impactor, many problems such as easy erosion and damage of the jet components, insufficient flow supply in the upper chamber of the inner cylinder when the piston moves at high speed,...

AI Technical Summary

Problems solved by technology

Although the hydraulic jet impactor directly controlled by the bistable jet element has been improved and optimized many times, it is still difficult to fundamentally solve the problem that the components are easy to erode, the service life is short, the effective working pressure difference of the impactor is small, and the flow rate in the upper cavity of the inner cylinder is difficult during the stroke. Meet the high-speed motion requirements of piston and hammer, etc.

In fact, the root cause of the above-mentioned difficulties is that the use of jet elements to directly control the impact mechanism cannot break through the limitations of its own structure and performance.

The bistable wall-attached jet element works according to the principle of Coanda, with a narrow input channel and an open working chamber inside. Therefore, in the face of the drilling industry's work requirements of using water and mud as the working medium and high flow rate, the jet element is used directly In principle, there are insurmountable technical bottlenecks in the controlled hydraulic jet impactor, such as the extremely small flow area at the inlet of the component, which causes extremely high throttling loss, and the attached wall jet is easily unstable due to the influence of load, etc.; in addition, For its application in the field of construction machinery hydraulic vibration technology, although the jet element has the characteristics of non-moving parts and pressure feedback control, because its maximum working pressure is not high, it cannot be directly used to drive the impact mechanism to obtain high impact energy, so lose practical value

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