Monitoring method for position of exhaust valve of marine low-speed machine

Abstract

The invention discloses a method for monitoring a position of an exhaust valve of a marine low-speed machine. The method comprises the steps that the upper portion of an exhaust valve rod of the marine low-speed machine is designed into a conical surface body; a position sensor is arranged at the position, close to the conical surface body, of an exhaust valve shell, so that when the exhaust valverod reciprocates up and down, the distance between a probe of the position sensor fixed to the exhaust valve shell and the conical surface body is changed; the position change of the up-and-down reciprocating motion of the exhaust valve rod is calculated according to the following formula: H = (LLi) * tan (a); and the position sensor feeds back a stroke signal of the exhaust valve to the outsideto a monitoring system in real time. The running state of the exhaust valve is monitored in real time, so that the exhaust valve can be opened and closed according to the preset timing in the runningprocess of the low-speed machine, and the performance exhaust requirements of the design are met.

Description

technical field [0001] The invention relates to a method for monitoring the position of an exhaust valve of a marine low-speed engine, which belongs to the technical field of diesel engines. Background technique [0002] On the one hand, according to the basic working principle of a marine two-stroke diesel engine, the exhaust valve is closed during work expansion and air compression in the cylinder, and the exhaust valve is open during ventilation and scavenging. Calculated at 100r / min, the exhaust valve opens and closes once every 0.6s on average, and the reciprocating frequency is high. Such as figure 1 As shown, the piston 2 and the buffer piston 3 reciprocate up and down together with the exhaust valve stem 1, while the exhaust valve stem 1 produces relative motion in the guide sleeve 4 and the parts of the exhaust valve are subjected to high temperature and high pressure. Under harsh working conditions, the lubrication of the exhaust valve stem 1, piston 2, and buffe...

AI Technical Summary

Problems solved by technology

Under harsh working conditions, the lubrication of the exhaust valve stem 1, piston 2, and buffer piston 3 is prone to failure during the up-and-down reciprocating motion, resulting in excessive wear of the exhaust valve stem; When the fitting clearance of the exhaust valve changes under harsh tooling, the up and down reciprocating movement of the exhaust valve stem 1 will be affected, and in serious cases, the exhaust valve stem will be stuck.

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