Marine fluid pump and control method thereof

Abstract

A marine fluid pump according to an aspect of the present invention includes a pump main body that pressurizes and discharges fluid by moving a piston using the pressure of working oil, a detection unit that detects a maximum movement amount of the piston during one fluid discharge, A control valve and a control unit that alternately switch between an ON state for supplying hydraulic oil to the pump main body and an OFF state for stopping the supply of hydraulic oil. The control unit derives the target movement amount of the piston based on the fluid ejection amount required for one fluid ejection, based on the difference between the target movement amount in the current fluid ejection and the maximum movement amount in the previous fluid ejection. And calculate the time correction value of the valve closing time of the control valve, consider this time correction value and correct the valve closing time when the fluid is ejected this time, and control the control valve so that the closed state of the control valve continues Corrected valve ON time.

Description

technical field [0001] The invention relates to a marine fluid pump and a control method thereof. Background technique [0002] Conventionally, marine fluid pumps for discharging fluids such as fuel and water have been used in marine diesel engines mounted on ships. For example, examples of marine fluid pumps include a fuel injection pump that pressurizes fuel injected into a cylinder to a fuel injection valve, and a fuel injection pump that injects fuel into a fuel flow passage that reaches the injection port of the fuel injection valve through piping from the discharge port of the fuel injection pump. Water injection pump, etc. Patent Document 1 describes a fuel injection pump driven and controlled by hydraulic oil supplied via a solenoid valve. [0003] In general, a marine fluid pump has a piston reciprocally movable in its longitudinal direction inside, and the piston is moved by the pressure of working oil supplied through a control valve to pressurize and discharge ...

AI Technical Summary

Problems solved by technology

However, when using an opening adjustment type solenoid valve as a control valve, in general, it is necessary to frequently measure the actual value of the movement amount of the piston during the ejection of the fluid, and it is necessary to adjust the movement amount of the piston every time. The deviation between the actual measured value and the target value is reflected in the adjustment of the opening degree of the control valve, so there is a concern that the structure of the device for controlling the movement amount of the piston with high precision will become complicated and the cost of the device will increase.

In addition, most opening-adjustable solenoid valves are not good at dealing with the incorporation of foreign matter, and it is easy to cause foreign matter to enter in an environment where a marine diesel engine is operating. Therefore, as a control valve for a marine fluid pump, an opening-adjustable solenoid valve may not Be applicable

Images