Impact performance optimization of a YDC valve-type double action hydraulic hammer

A YDC type hydraulic hammer is a new valve-type double action hydraulic hammer suitable for oil and gas well drilling. It is hard to find out the optimal matching relationship among various factors based on experience and experiments, for the matching relationships of inner pressure is complex and the impact performance is influenced by many factors. In this paper, the operating principle of a YDC type hydraulic hammer was investigated, the force applied to the main moving components (valve core and hammer) was analyzed and a dynamic model of valve core and hammer in each operating stage was established. Then, a hydraulic hammer performance optimization design software was developed on the Matlab software platform, and the performance parameters calculated by the software were compared with the laboratory test results. The following research results were obtained. Firstly, single impact energy, impact frequency and impact power increase with the increase of pump displacement or the decrease of flow bean diameter, and they increase firstly and then decrease with the increase of area difference between the upper and lower chambers. Secondly, with the increase of hammer weight, single impact energy and impact power increase, but the impact frequency decreases slowly. Thirdly, with the increase of hammer travel, single impact energy presents an increasing trend, impact frequency presents a decreasing trend and impact power basically remains unchanged. Fourthly, with the increase of valve core weight, single impact energy presents an increasing trend, while both impact frequency and impact power decrease. Fifthly, the parameter combination corresponding to the optimal single impact energy and impact power is A5B1C5D4E3F2, and the effect of displacement on single impact energy and impact power is the greatest. It is concluded that under the existing displacement and pressure of drilling pumps, the impact performance of the hydraulic hammer can be increased effectively by improving the structure of the hydraulic hammer and thus increasing its work displacement.