Fluid pump for ship and method for controlling same

Abstract

A fluid pump for a ship, which is one aspect of the present invention, comprises a pump body that pressurizes and discharges a fluid by moving a piston in which pressure of hydraulic oil is used, a detection unit that detects a maximum movement amount of the piston in one fluid discharge, a control valve that selectively switches between an ON state in which hydraulic oil is supplied to the pump body and an OFF state in which the supply of hydraulic oil is stopped, and a control unit. The control unit derives a target movement amount of the piston in accordance with a fluid discharge amount required in one fluid discharge. On the basis of the difference between the target movement amount in the current fluid discharge and the maximum movement amount in the previous fluid discharge, the control unit calculates a time correction value for a valve ON time of the control valve, adds this time correction value to correct the valve ON time during the current fluid discharge, and controls thecontrol valve so that the valve continues to be in an ON state for the 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

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