Fuel supply device

Patent metadata

Field	Value
Publication number	US-2016245246-A1
Application number	US-201415031094-A
Country	US
Kind code	A1
Filing date	Nov 3, 2014
Priority date	Nov 5, 2013
Publication date	Aug 25, 2016
Grant date	—

Abstract

A fuel supply device includes a fuel pump and a filter case that houses a fuel filter, a fuel pumped by the fuel pump from inside a fuel tank is filtered by the fuel filter and supplied from inside the filter case toward an internal combustion engine, and the filter case includes a case body having a closed bottom shape that forms a housing chamber of the fuel filter, a case cap that covers an aperture of the case body by being joined to the case body, and a residual pressure retention valve that, when the fuel pump is stopped, retains a pressure of the fuel supplied from inside the filter case toward the internal combustion engine, the residual pressure retention valve being disposed at a joint boundary of the case body and the case cap.

First claim

1 . A fuel supply device, comprising:
a fuel pump; and a filter case that houses a fuel filter, wherein a fuel pumped by the fuel pump from inside a fuel tank is filtered by the fuel filter and supplied from inside the filter case toward an internal combustion engine, and the filter case includes
a case body having a closed bottom shape that forms a housing chamber of the fuel filter,
a case cap that covers an aperture of the case body by being joined to the case body, and
a residual pressure retention valve that, when the fuel pump is stopped, retains a pressure of the fuel supplied from inside the filter case toward the internal combustion engine, the residual pressure retention valve being disposed at a joint boundary of the case body and the case cap.

2 . The fuel supply device of claim 1 , wherein
the residual pressure retention valve is assembled from
a valve housing that forms a valve seat, the valve housing being joined to the case body and the case cap, and
a valve element housed in the valve housing so as to be separatable and seatable with respect to the valve seat, the valve element retaining the pressure of the fuel supplied from inside the filter case toward the internal combustion engine by seating on the valve seat.

3 . The fuel supply device of claim 2 , wherein
the valve housing is joined to the case body and the case cap on a common imaginary plane.

4 . The fuel supply device of claim 2 , wherein
the valve housing is press fit into the case body or the case cap.

5 . The fuel supply device of claim 2 , wherein
the valve housing is held between the case body and the case cap.

6 . The fuel supply device of claim 5 , wherein
the filter case includes a fuel passage that, by being turned back in an axial direction, is in communication with the internal combustion engine by way of the residual pressure retention valve, the fuel passage penetrates the valve housing at at least one of an upstream location and a downstream location from a turning back portion formed in the case cap, the upstream location and the downstream location being formed in the case body, and the valve element separates from and seats on the valve seat at the upstream location or the downstream location which penetrate the valve housing.

7 . The fuel supply device of claim 1 , wherein
the residual pressure retention valve is an external residual pressure retention valve having a valve element that, when the fuel pump is operating, opens and becomes locked by a valve stopper, the external residual pressure retention valve being a spring-less type external residual pressure retention valve that, when the fuel pump is stopped, retains a pressure of the fuel supplied toward the internal combustion engine, the filter case has disposed therein a fuel passage including a communication port, the communication port being in communication with the housing chamber at a location downstream from the fuel filter, the fuel passage allowing fuel, which is discharged from the communication port toward the internal combustion engine, to flow, the filter case has disposed therein an internal residual pressure retention valve having a valve element that, when the fuel pump is operating, resists a spring reaction force to open, the internal residual pressure retention valve being a spring-biased type residual pressure retention valve that, when the fuel pump is stopped, retains a pressure of the fuel in the housing chamber, the communication port opens at an offset location in the fuel passage, the offset location being offset from the internal residual pressure retention valve toward the external residual pressure retention valve, the fuel passage has formed therein
an external passage portion that allows fuel, which is for being discharged toward the internal combustion engine, to flow from the communication port toward the external residual pressure retention valve, and
an internal passage portion that allows fuel to flow from the communication port toward the internal residual pressure retention valve, the internal passage portion narrowing down a fuel flow more than the external passage portion, and
when a passage cross-sectional area of the internal passage portion is converted into a passage cross-sectional area of a cylindrical pipe, a passage diameter D of this cylindrical pipe and a length L of the internal passage portion satisfy the equation L/D≧3.

8 . The fuel supply device of claim 7 , further comprising:
a relief valve having a valve element, the relief valve being a spring-biased relief valve that releases a pressure of fuel supplied toward the internal combustion engine through the fuel passage, the valve element resisting a spring reaction force to open in order to release this pressure, wherein the filter case includes a relief passage in the fuel passage, the relief passage guiding, to the relief valve, fuel which is diverted, at a location downstream from the external residual pressure retention valve, from a flow toward the internal combustion engine.

9 . The fuel supply device of claim 7 , wherein
the filter case includes a relay passage that relays between the housing chamber and the communication port.

10 . The fuel supply device of claim 9 , wherein
the communication port opens to the external passage portion at the offset location, and the internal passage portion opens to a spaced location in the external passage portion, the spaced location being spaced away from the relay passage to interpose the internal residual pressure retention valve, the internal passage portion thereby communicating with the communication port through the external passage portion.

11 . The fuel supply device of claim 10 , wherein
a flow direction of fuel in the relay passage is inclined with respect to the flow direction of fuel in the internal passage portion, a fuel flow from the relay passage thereby flowing through the external passage portion and turning back toward the internal passage portion.

12 . The fuel supply device of claim 7 , wherein
the communication port opens to the external passage portion at the offset location, thereby communicating with the internal passage portion through the external passage portion.

13 . The fuel supply device of claim 7 , further comprising:
a jet pump that transfers fuel inside the fuel tank to a vicinity of the fuel pump by narrowing down and spraying out a fuel discharged from the internal passage portion through the internal residual pressure retention valve.

Assignees

• Denso Corp
• Kyosan Denki Kk

Inventors

• Niwa Yutaka
• Takahashi Hideto
• Okazono Tetsuro
• Oki Hironobu
• Sugiyama Akinari
• Ishitoya Akihiro

Classifications

• F02M37/46

  Filters structurally associated with pressure regulators · CPC title

• F02M37/12

  fluid-driven, e.g. by compressed combustion-air · CPC title

• F02M37/14 Primary

  the pumps being combined with other apparatus · CPC title

• F02M37/0029

  Pressure regulator in the low pressure fuel system (pressure regulator in low-pressure injection apparatus F02M69/54) · CPC title

• F02M37/106 Primary

  the pump being installed in a sub-tank · CPC title