Pump control module

Abstract

A pump module that controls and varies the pressure of a fluid within a hydraulic system. The module includes a housing which has an inlet port, an outlet port and a return port. The inlet port is typically coupled to a pump. The return port is typically connected to a fluid reservoir. The outlet port is typically connected to a working device such as the fuel injector of an internal combustion engine. The module contains a spring loaded variable volume accumulator which maintains the fluid pressure at the outlet of the module. The module also has a three-way valve that provides fluid communication between the inlet port and the outlet port when in a first position, and fluid communication between the inlet port and the return port when in a second position. The module further includes a pressure transducer that senses the fluid pressure at the outlet port and provides a corresponding pressure feedback signal to an electronic controller. The electronic controller moves the three-way valve to the second position when the outlet fluid pressure exceeds a threshold value. Opening the valve allows the fluid provided by the pump to be directed to the reservoir through the return port, thereby bypassing the working device. Shorting the pump output to the reservoir reduces the work required by the pump. The fluid pressure within the system can be changed by varying the threshold value.

Dependencies are inferred from the claim text.