Elastic sealing member for fuel tank

Abstract

A sub sealing projection of an elastic sealing member for a fuel tank is entirely angled, and shaped so as to satisfy 20°≦θ1(angle defined by its upper surface and a cylindrical sealing portion)≦35°, 50°≦θ2(angle defined by its lower surface and the cylindrical sealing portion)≦70°, 0.4≦B (radial distance between a portion having a diameter corresponding to an inner peripheral surface of the cylindrical wall portion and a leading end of the sub sealing projection)/A (maximum projecting distance of the sub sealing projection)≦0.55, and a leading end portion of the sub sealing projection is shaped so as to satisfy a condition, 0.1≦R (curvature radius of cross-section thereof)/C(length of a base portion of the sub sealing projection)≦0.2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a state that an elastic sealing member according to one embodiment of the present invention is assembled or attached in a fuel tank.

FIG. 2 is an exploded view of a relevant part of FIG. 1.

FIG. 3 is an enlarged view of a relevant part of FIG. 1.

FIG. 4 (A) is a sectional view showing the elastic sealing member of FIG. 1.

FIG. 4 (B) is a sectional view showing a sub sealing projection of the elastic sealing member of FIG. 1.

FIG. 5 (A) is a view showing another embodiment of the present invention.

FIG. 5 (B) is a view showing yet another embodiment of the present invention.

FIG. 6 is a view (graph) showing a relationship between compressive/elastic deformation volume of a main sealing protrusion and load during tightening of a screw-on cap.

FIG. 7 is a view showing one example of a conventional elastic sealing member adapted for a fuel tank made of metal.

FIG. 8 is a view showing a state that a conventional elastic sealing member adapted for a fuel tank made of resin is assembled or attached in the fuel tank.

FIG. 9 (A) is a sectional view showing the elastic sealing member of FIG. 8.

FIG. 9 (B) is a sectional view showing a sub sealing projection of the elastic sealing member of FIG. 8.

FIG. 9 (C) is a sectional view showing a flange sealing portion of the elastic sealing member of FIG. 8.

FIG. 10 (A) is an overall view of the elastic sealing member for showing a problem of the elastic sealing member of FIG. 8.

FIG. 10 (B) is the view of a sub sealing projection for showing the problem of the elastic sealing member of FIG. 8.

FIG. 10 (C) is a sectional view taken along line C-C in FIG. 10 (B).

FIG. 10 (D) is a sectional view taken along line D-D in FIG. 10 (B).

Claims

1. An elastic sealing member for a fuel tank made of resin and adapted for a vehicle, the elastic sealing member being arranged between a cylindrical wall portion standing upright on an outer surface of a tank body of the fuel tank and including an opening portion on an upper end of the cylindrical wall portion, and a base body of a fuel pump unit for holding a fuel pump to provide a seal therebetween, the base body having a fit portion of cylindrical shape for fitting to an inner peripheral surface of the cylindrical wall portion, a closing portion on an upper end thereof for closing the opening portion of the cylindrical wall portion, and an annular flange portion projecting radially outwardly at an upper position with respect to an upper end of the cylindrical wall portion, the elastic sealing member for the fuel tank, comprising: a cylindrical sealing portion interposed and arranged between the base body and the cylindrical wall portion,an annular flange sealing portion projecting radially outwardly on an upper end of the cylindrical sealing portion, the flange sealing portion being sandwiched between an upper end surface of the cylindrical wall portion and the flange portion of the base body by tightening a screw-on cap on an externally threaded portion of an outer peripheral surface of the cylindrical wall portion,wherein:the flange sealing portion is formed with a main circumferentially annular sealing protrusion protruding from a front surface thereof facing the flange portion of the base body and a rear surface thereof facing the upper end surface of the cylindrical wall portion, respectively,the cylindrical sealing portion is formed with a sub circumferentially annular sealing projection projecting radially outwardly from an outer peripheral surface thereof,the main sealing protrusions provide a sealing function on the flange sealing portion and the sub sealing projection provides a sealing function on the cylindrical sealing portion,the sub sealing projection is entirely angled in an inserting direction of the elastic sealing member into the cylindrical wall portion and defines a maximum outer diameter larger than an inner diameter of the cylindrical wall portion,when angles defined by upper and lower surfaces of the sub sealing projection with respect to the outer peripheral surface of the cylindrical sealing portion at a base portion thereof are indicated by θ1, θ2 respectively, a radial distance of the sub sealing projection between a portion having a diameter corresponding to the inner peripheral surface of the cylindrical wall portion and a leading end of the sub sealing projection is indicated by B, and a maximum projecting distance of the sub sealing projection in a radial direction with respect to the outer peripheral surface of the cylindrical sealing portion is indicated by A, θ1, θ2, A, and B satisfy following equations, 20°≦θ1≦35°50°≦θ2≦70°0.4≦B/A≦0.55, andthe sub sealing projection has an arcuate cross-section on a leading end portion thereof, when a curvature radius of the leading end portion of the sub sealing projection is indicated by R, and an axial length of the base portion of the sub sealing projection is indicated by C, a relationship between R and C satisfies the following condition, 0.1≦R/C≦0.2.

2. The elastic sealing member as set forth in claim 1, wherein the main sealing protrusions are shaped such that when the entire flange sealing portion including the main sealing protrusions are compressed and elastically deformed within a specified deformation volume range by tightening the screw-on cap, the flange portion of the base body of the pump unit and the upper end surface of the cylindrical wall portion of the fuel tank do not abut the front and rear surfaces of the flange sealing portion.