毕业论文外文译文组合机床动力滑台液压系统常见故障的分析与排除

毕业论文外文译文组合机床动力滑台液压系统常见故障的分析与排除内容摘要：

inder 10 →the left frame of reversal valve 4→sequence valve 18→back pressure valve 19→oil box Working Feed After the I working feed es to an end, the travel iron stop presses the electric travel switch and sends a signal to make the electromag 3YA of the solenoid valve 14 charged with electricity, and then the left frame of the valve accesses to the system and cuta off the oil line, but the oil can only flow into the left chamber of hydraulic cylinder 10 after passing through the speed control valve 15. Now, the sliding table is converted into the “II Working Feed, and its motion speed is controlled by the speed control valve 15, but can only be adjusted within the smaller scope than the I working feed. However, the other parts of the inlet oil line as well as the outlet oil line are identical to the I working feed. 四川大学锦江学院毕业论文（设计） 外文译文 11 Stay of the Dead Iron Block When moving to the travel destination at the speed of the “II Working Feed, the sliding table will e across the dead iron stop and stop moving. However, by now, the hydraulic pump 2 continues to flow the pressure oil to hydraulic pump 2, and makes the oil pressure in the system increased further. When the oil pressure is equal to the settling pressure of the pressure relay 13, the pressure relay motion sends a signal to the time relay。 the stay time before next motion is controlled by the time relay, to process the end face of the parts. Under the present circumstances, the oil delivering amount of the pump is highly small, which is only used to make up the leakages,while the system is in the pressurekeeping state. Fast Reverse After the sliding table stays at the dead iron stop for a while, the time relay sends a signal to let the electromag 1YA power off but the 2YA power on, and then the right frames of both the directional valves 5 and 4 access to the system to realize the inverting. The oil enters the right chamber of the hydraulic cylinder 10 and makes the sliding table invert speedily. As it is an idle load when the sliding table is inverting, the oil pressure in the system is low, and the flow amount of the limited pressure type oneway variable pump 2 is automatically enlarged to the maximum, and the effective areas ratio between the rodless chamber and rod chamber of the hydraulic cylinder is 2:1, so the sliding table rapidly invert at the same speed to the fast forward. When the sliding table rapidly inverts to the termination of the fast forward, the travel valve 11 is loosened, and the oil return is smoother. The control oil line can be described below: Inlet oil line: variable pump 2→right frame of directional valve 2→one way valve 7→right chamber of directional valve 2。 Outlet oil line: left chamber of directional valve 4→throttling valve 8→right chamber of directional valve 5→oil box The details of the main oil line are as shown below: Inlet oil line: Variable pump 2→one way valve 3→right chamber of directional valve 4→right chamber of hydraulic cylinder 10 Outlet oil line: right frame of hydraulic cylinder 10→one way valve 12→right chamber of directional valve 4→oil box 四川大学锦江学院毕业论文（设计） 外文译文 12 Fast Retreat InSitu to Stop When the sliding table rapidly inverts to the insitu, the iron stop presses the termination travel switch and sends a signal to make the electromags 1YA, 2YA and 3YA power off, and then the solenoid directional valve 5 and hydraulic directional valve 4 are in the central frame, and the oil lines of both the left and right chambers of hydraulic cylinder are cut off and then the hydraulic cylinder is in a clamp state, and the sliding table stops working. By now, the oil flowed by the variable pump 2 flows into the oil return box necessarily after passing through the oneway pumps 3 and 4, and then the system is in an unloading state. 2 Analysis on the No Working Feed Faultof the Power Sliding Table and the Removal Steps Analysis on the Reasons for the Fault The power sliding table in modular machine tool keeps a normal speed in the fast feeding, and es to a halt at the beginning of processing. Based on the learnt knowledge of the principles of all kinds of hydraulic ponents and the maintenance experiences from work, and through a detailed analysis, the main reasons for causing the no working feed fault may be the powerful cutting, insufficient system pressure, leakage, no oil supply by hydraulic pump or insufficient oil delivery amount, abrasion of hydraulic valve internal ponents, broken line or locking, or the abrasion of hydraulic cylinder internal ponents resulting in the inner leakage or the sealing ponents squashing in the cylinder wall to arouse the increasing resistance of the executive ponents, etc. Fault Removal Steps Due to the leak tightness of the hydraulic system, the hydraulic fault is not as intuitional as the mechanical failures。 the fault measurement is not as convenient as that of electric problems and is really uneasy to judge directly.。