Failure Analysis and Solution on the Loader Hydraulic Control Flow Amplification Valve

This paper conducts an in-depth analysis of the continuous high impact pressure of the hydraulic-controlled flow amplification valve of loaders during durability tests. It is found that the shuttle valve commonly experiences a neutral position pressure buildup during load pressure selection. The impact waveform curve of the original flow amplification valve under durability failure is presented, and two innovative solutions are proposed: integrating a constant flow valve into the main valve body, and acquiring LS pressure from the main valve spool. Experimental verification is mainly carried out on the integrated constant flow valve scheme, and the durability test impact waveform curve at 1 Hz is successfully obtained. The research results show that both solutions can effectively eliminate the LS neutral position pressure buildup of the main valve and resolve the technical problem of continuous high pressure of the main pump in the durability test. The solutions significantly improve the buffering effect of steering impact, provide new ideas for the product design of flow amplification valves, and have important theoretical guiding significance for the commissioning of loader steering performance.