Protection device for limiting pump cavitation in common rail system
AssigneeCaterpillar Inc.
InventorsSunil Bean, Daniel Puckett, Michael Sattler
Life of this patent
Estimating the term…
Abstract
A pressurized fuel system for an engine includes a fuel pump in a pump protection device structured to drain pressurized fuel from a common rail to provide fuel flow through the fuel pump that limits cavitation. The device includes a valve mechanism having a first valve and a second valve that are movable to an open position and a closed position respectively, in response to valve opening and valve closing rail pressures. The active pressure range of the device may be a medium pressure range.
Claims20
A fuel system for an internal combustion engine comprising:
- a fuel supply;
- a common rail;
- a fuel pump coupled with the fuel supply and structured to pressurize a fuel from the fuel supply for conveying to the common rail;
- a plurality of fuel injectors coupled with the common rail and structured to inject the fuel into a plurality of cylinders in an internal combustion engine;
- and
- a pump protection device structured to drain pressurized fuel from the common rail to provide a fuel flow through the fuel pump that limits cavitation within the fuel pump, the pump protection device including a valve body having an inlet fluidly connected with the common rail, a drain outlet, and a valve mechanism positioned within the valve body fluidly between the inlet and the outlet;
- the valve mechanism including a first valve member movable between a closed position inhibiting fluid flow through the inlet, and an open position, and a second valve member movable between a closed position inhibiting fluid flow through the outlet, and an open position, and at least one biases biasing the first valve member and the second valve member toward the closed position and the open position, respectively;
- the second valve member having a closing hydraulic surface, and the first valve member blocking the closing hydraulic surface from the inlet when the first valve member is at the closed position.
A pump protection device for limiting cavitation in a pump in a fuel system comprising:
- a valve body having an inlet structured to fluidly connect with a common rail in a fuel system, and a drain outlet;
- a valve mechanism positioned within the valve body fluidly between the inlet and the drain outlet;
- the valve mechanism including a first valve member movable between a closed position in contact with a first valve seat formed on an inlet fitting within the valve body to inhibit fluid flow through the inlet, and an open position, and a second valve member movable between a closed position in contact with a second valve seat within the valve body to inhibit fluid flow through the drain outlet, and an open position;
- and the valve mechanism further including at least one biaser biasing the first valve member and the second valve member toward the closed position and the open position, respectively.
A method of operating a pressurized fluid system comprising:
- supplying pressurized fluid at a valve opening pressure to a first valve in a pump cavitation protection device fluidly connected with a common rail;
- opening a valve seat by way of the first valve in response to the supplying of the pressurized fluid at the valve opening pressure;
- draining the pressurized fluid at the valve opening pressure from the common rail to an outlet of the pump cavitation protection device to produce a fluid flow through a pump supplying the pressurized fluid to the common rail that limits cavitation within the pump;
- supplying pressurized fluid through the valve seat opened by the first valve at a valve closing pressure greater than the valve opening pressure to a second valve in the pump cavitation protection device;
- and
- closing the second valve in response to the supplying of the pressurized fluid at the valve closing pressure such that the draining of the pressurized fluid is stopped.
Dependencies are inferred from the claim text.