US20100072200A1

US20100072200A1 - Internally Mounted Fuel Tank Inlet Check Valve

Info

Publication number: US20100072200A1
Application number: US12/233,623
Authority: US
Inventors: Rebecca J. Marquardt
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2008-09-19
Filing date: 2008-09-19
Publication date: 2010-03-25

Abstract

An inlet check valve (ICV) assembly for a plastic fuel tank in which the ICV housing thereof is attached internally to the tank shell, and the fuel fill pipe/hose assembly has attachment to the tank shell. The fuel tank includes a shell spout having a spout spud, wherein an internal mounting surface is disposed circumspect the shell spout. The ICV housing includes an inversion of the weld pad for plastic welding at the internal mounting surface of the tank shell. In one embodiment, the ICV assembly has a high profile upper sleeve with a sleeve spud to which the fuel fill pipe/hose assembly also attaches.

Description

TECHNICAL FIELD

The present invention relates to plastic fuel tanks for motor vehicles, and more particularly to a fuel fill inlet check valve which is internally mounted to the fuel tank shell.

BACKGROUND OF THE INVENTION

Motor vehicle fuel tanks are commonly composed of a plastic shell and provide not only a reservoir for fuel but also must have accommodation for adding fuel, delivering fuel (i.e., to the engine) and monitoring the amount of the fuel therein. It has become a common practice to provide an inlet check valve at the interface of the fuel fill pipe/hose assembly with the fuel tank shell. In this regard, the inlet check valve (ICV) provides a one-way valve in which fuel may pass into the fuel tank during fueling, but is prevented from exiting the fuel tank.
Existing plastic fuel tanks utilize an ICV assembly having an ICV housing which is externally plastic welded to the tank shell. In this regard, FIGS. 1A and 1B depict an example of a prior art ICV assembly 10 for a motor vehicle fuel tank 12.
The ICV assembly 10 includes: a plastic ICV housing 14 having an upper sleeve 16 with a spud 16 a, an annular flange 18 with a weld pad 18 a, and a lower sleeve 20; and further includes an ICV member 22 mounted to the lower sleeve, wherein the ICV member includes an ICV 22 a which operates as a one-way valve allowing fuel to enter the fuel tank, but not to exit. The ICV housing 14 is attached to the tank shell 12 a of the fuel tank 12 circumspect a fuel entry opening 12 b formed therein. A plastic welding apparatus (not shown, but well known in the art) heats the tank shell 12 a adjacent the fuel entry opening 12 b to thereby provide a pre-heated flat external mounting surface 12 c of the tank shell. Simultaneously, the plastic welding apparatus also heats the annular flange 18 such that the weld pad 18 a thereof is also pre-heated. The plastic welding apparatus then presses the weld pad 18 a to the mounting surface 12 c, whereby a plastic weld 25 therebetween is established which seals the ICV housing 14 to the fuel tank shell 12 a.
The fuel fill pipe/hose assembly 24 is tightly fitted upon the upper sleeve 16, including an interference fit with respect to the spud 16 a. An adjustable annular clamp 26 contracts the fuel fill pipe/hose assembly onto the upper sleeve and thereby seals the fuel fill pipe/hose assembly with respect to the ICV housing.
In operation, a user pumps fuel into the fuel fill pipe/hose assembly, wherein the fuel passes into the fuel tank through the ICV housing and the ICV assembly. The fuel cannot pass back into the fuel fill pipe/hose assembly from the fuel tank due to the one-way operation of the ICV of the ICV assembly.
Since externally welded ICV housings depend on the integrity of the welding process to ensure the weld secures the ICV housing in all vehicle conditions, preventing leakage or permeation of fuel liquid and vapor, it would be desirable if somehow: 1) the ICV housing could be attached to the fuel tank other than externally, and 2) the could have an attachment directly to the fuel tank.

SUMMARY OF THE INVENTION

The present invention is an ICV assembly for a plastic fuel tank in which the ICV housing thereof is attached internally to the tank shell of the fuel tank and the fuel fill pipe/hose assembly has a direct attachment to the tank shell of the fuel tank.
The plastic fuel tank according to the present invention includes a plastic shell having a shell spout with a spout spud, wherein an internal mounting surface is disposed circumspect the shell spout. The ICV assembly according to the present invention may utilize a conventional ICV member, as for example that depicted at FIG. 1B; however, the ICV housing is modified according to the present invention, including an inversion of the weld pad for plastic welding at an internal mounting surface of the tank shell.
In a first preferred embodiment of the ICV assembly according to the present invention, the inverted weld pad is plastic welded to the internal mounting surface of the tank shell. The ICV assembly has a high profile upper sleeve which is received by the shell spout, wherein the shell spout is formed integrally of the tank shell. The shell spout has a spout spud, and the upper sleeve has a sleeve spud externally disposed with respect to the terminus of the shell spout, wherein the fuel fill pipe/hose assembly is tightly fitted upon the shell spout and the sleeve spud, including an interference fit with respect to the spout and sleeve spuds. An adjustable annular clamp, for example, contracts the fuel fill pipe/hose assembly onto the shell spout, whereby the spout and sleeve spuds are further tightly fitted, and thereby sealing the fuel fill pipe/hose assembly independently with respect to both the tank shell and the ICV assembly.
In a second preferred embodiment of the ICV assembly according to the present invention, the inverted weld pad is plastic welded to an internal mounting surface of the tank shell. The ICV assembly has a low profile upper sleeve which is received by a shell spout formed integrally of the tank shell. The shell spout includes a spout spud, wherein the fuel fill pipe/hose assembly is tightly fitted upon the shell spout, including an interference fit with respect to the spout spud. An adjustable annular clamp, for example, contracts the fuel fill pipe/hose assembly onto the shell spout, whereby the spout spud is further tightly fitted, and thereby sealing the fuel fill pipe/hose assembly with respect to the tank shell.
By way of exemplification, a plastic welding apparatus (known in the art, but now having a suitably configured robotic arm) enters the tank shell, for example through the shell opening for the fuel pump module (or other pre-selected shell opening), to thereby heat the plastic inverted weld pad and the internal mounting surface of the plastic tank shell. In this regard, the internal mounting surface of the tank shell complies generally with the geometry utilized in the prior art for the above discussed external welding operation; however, now the flat mounting surface is disposed at the inside surface of the tank shell.
The present invention provides, in comparison with the prior art as depicted at FIGS. 1A and 1B, enhanced protection from fuel leakage or permeation through the uninterrupted, one piece interface of the fuel fill pipe/hose assembly with respect to the shell spout of fuel tank. The advantage of an internally mounted ICV is that if somehow liquid fuel and/or fuel vapor escaped through the plastic weld of the ICV assembly to the tank shell, then the escaped fuel would be trapped inside the fuel tank, itself, and/or the fuel fill pipe/hose assembly, thus obviating any issues related to liquid fuel and vapor somehow getting outside of the fuel tank at the ICV assembly.
Accordingly, it is an object of the present invention to provide an ICV assembly for a plastic fuel tank in which the ICV housing thereof is attached internally to the fuel tank and the fuel fill pipe/hose assembly has a direct attachment to the tank shell of the fuel tank, thus eliminating any issues related to liquid fuel and vapor somehow getting outside of the fuel tank at the ICV assembly.
This and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a prior art plastic fuel tank, showing in particular a fuel fill pipe/hose assembly connected with a prior art ICV assembly.

FIG. 1B is a side sectional view of the prior art plastic fuel tank and prior art ICV assembly of FIG. 1A.

FIG. 2 is a elevational side view of a first embodiment of the present invention including a high profile upper sleeve with sleeve spud.

FIG. 3 is a elevational side view of a second embodiment of the present invention including a low profile upper sleeve.

FIG. 4 is a broken-away, sectional side view of the first embodiment of the present invention including a high profile upper sleeve, shown received by a shell spout of a plastic fuel tank according to the present invention.

FIG. 5 is a broken-away, sectional side view of the second embodiment of the present invention including a low profile upper sleeve, shown received by a shell spout of a plastic fuel tank according to the present invention.

FIG. 6A is a schematic view of an ICV assembly having an inverted weld pad being installed with respect to a shell spout and internal mounting surface of a plastic fuel tank according to the present invention.

FIG. 6B is a flow chart indicating method steps for the installation process schematically exemplified at FIG. 6A.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the Drawing, FIGS. 2 through 6B depict various aspects of the ICV assembly 100 according to the present invention.
Referring firstly to FIGS. 2 and 4, a first preferred embodiment of the ICV assembly 100, 100′ is shown. The ICV assembly 100′ includes a plastic ICV housing 102 having an upper sleeve 104 with a sleeve spud 104 s adjacent the sleeve terminus 104 t, an annular flange 106 having a weld pad 106 a, and a lower sleeve 108, wherein the weld pad is “inverted” in the sense that the upper sleeve is disposed in upstanding relation to the weld pad (in contradistinction to the prior art of FIG. 1B, the lower sleeve 20 is disposed in upstanding relation to the weld pad). The ICV assembly 100′ further includes an ICV member 110 mounted to the lower sleeve, wherein the ICV member includes an ICV 110 a which operates as a one-way valve allowing fuel to enter the fuel tank, but not to exit.
The plastic fuel tank 120 has a plastic tank shell 120 a having a shell spout 122 formed at the fuel opening 124 and extending outwardly from the tank shell. Adjacent the terminus 122 t of the shell spout 122 is a spout spud 122 s. The shell spout is an integral component of the tank shell, formed, for example, during the fabrication process (as for example blow molding) of the fuel tank. An internal surface of the tank shell 120 a adjacent and circumspect the spout opening 124 of the tank shell is a mounting surface 126, having a predetermined configuration for interfacing with the inverted weld pad 106 a, as for example a flat profile.
The inner diameter 122 b of the spout passage 122 p of the shell spout 122 is preselected so that the upper sleeve 104 with its sleeve spud 104 s is able to be passed (or pressed) through the shell spout such that when the inverted weld pad 106 a contacts the mounting surface 126, the sleeve spud is exposed, disposed, for example, in general adjacency to the terminus 122 t and the spout spud 122 s. In this regard, the upper sleeve 104 has a “high profile” in the sense that the sleeve spud 104 s is exposed with respect to the shell spout when the upper sleeve is fully seated in the shell spout 122, wherein, generally for example, the upper sleeve has a length longer than that of the lower sleeve 108.
A plastic welding apparatus is utilized to heat the inverted welding pad 106 a and the internal mounting surface 126, then press the inverted welding pad against the internal mounting surface to provide a sealing plastic weld 125 therebetween, as will be detailed hereinbelow with respect to FIGS. 6A and 6B.
As shown at FIG. 4, the fuel fill pipe/hose assembly 130 is tightly fitted upon the shell spout 122 and the sleeve spud 104 s, including an interference fit with respect to the spout and sleeve spuds 122 s, 104 s. An adjustable annular clamp 132, for example, contracts the fuel fill pipe/hose assembly onto the shell spout, whereby the spout and sleeve spuds are further tightly fitted, and thereby sealing the fuel fill pipe/hose assembly independently with respect to both the tank shell 120 a and the ICV housing 102. To facilitate a tight fit between the fuel fill pipe/hose assembly 130 and each of the spout and sleeve spuds 122 s, 104 s, the fuel fill pipe/hose assembly (at the hose endform thereof, for example) is shown having end flaring 130 a.
Referring next to FIGS. 3 and 5, a second preferred embodiment of the ICV assembly 100, 100″ is shown. The ICV assembly 100″ includes a plastic ICV housing 102′ having a upper sleeve 104′ with a sleeve spud 104 s′, an annular flange 106′ having a weld pad 106 a′, and a lower sleeve 108′, wherein the weld pad is “inverted” in the sense that the upper sleeve is disposed in upstanding relation to the weld pad (in contradistinction to the prior art of FIG. 1B, the lower sleeve 20 is disposed in upstanding relation to the weld pad). The ICV assembly 100″ further includes an ICV member 110′ mounted to the lower sleeve, wherein the ICV member includes an ICV 110 a′ which operates as a one-way valve allowing fuel to enter the fuel tank, but not to exit.
The plastic fuel tank 120′ has a plastic tank shell 120 a′ having a shell spout 122′ formed at the fuel opening 124′ and extending outwardly from the tank shell. Adjacent the terminus 122 t′ of the shell spout 122′ is a spout spud 122 s′. The shell spout is an integral component of the tank shell, formed during the fabrication process (as for example blow molding) of the fuel tank. An internal surface of the tank shell 120 a′ adjacent and circumspect the spout opening 124′ of the tank shell is a mounting surface 126′, having a predetermined configuration for interfacing with the inverted weld pad 106 a′, as for example a flat profile.
The inner diameter 122 b′ of the spout passage 122 p′ of the shell spout 122 is preselected so that the upper sleeve 104′ is receivable into the shell spout when the inverted weld pad 106 a′ contacts the mounting surface 126′, wherein the upper sleeve is disposed entirely within the shell spout (i.e., the sleeve terminus 104 t′ is disposed within the shell spout). In this regard, the upper sleeve 104′ has a “low profile” in the sense that the upper sleeve is disposed entirely inside the shell spout 122′ when the upper sleeve is fully seated therein, wherein, generally for example, the upper sleeve has a length shorter than that of the lower sleeve 108′.
A plastic welding apparatus is utilized to heat the inverted welding pad 106 a′ and the internal mounting surface 126′, then press the inverted welding pad against the internal mounting surface to provide a sealing plastic weld 125′ therebetween, as will be detailed hereinbelow with respect to FIGS. 6A and 6B.
As shown at FIG. 5, the fuel fill pipe/hose assembly 130′ is tightly fitted upon the shell spout 122′, including an interference fit with respect to the spout spud 122 s. An adjustable annular clamp 132′, for example, contracts the fuel fill pipe/hose assembly onto the shell spout, whereby the spout spud is further tightly fitted, and thereby sealing the fuel fill pipe/hose assembly with respect to the tank shell 120 a′.
An installation set-up is shown schematically at FIG. 6A, utilizing, by way of example, the embodiment of FIGS. 2 and 4. A plastic welding apparatus (for example, robotic or mechanically driven) 150, known in the art, now having a suitably configured robotic or mechanically driven arm 152, enters the tank shell 120 a for example through a selected tank shell opening 154, for example an opening utilized for the fuel pump module. The plastic welding apparatus, in this example a robotic arm, provides heat to the plastic inverted weld pad 106 a and heating the internal mounting surface 126 of the plastic tank shell. After heating, the plastic welding apparatus 150 then presses the inverted welding pad against the internal mounting surface, thereby plastic weld sealing the ICV housing 202 to the fuel tank 120.
FIG. 6B depicts a flow chart 200 exemplifying a methodology for carrying out the present invention.
At Block 202 the plastic fuel tank is fabricated, integrally with the shell spout. By way of exemplification, the shell spout, shell spud and the internal mounting surface are blow molded along with the rest of the blow molded tank shell during a plastic blow molding operation. The fuel filler hole and the spout passage may be formed during the blow molding operation by several methods, such as for example, utilizing a push through rod insert, located in the blow molding tool, or by being cut post blow molding.
At Block 204 the ICV assembly is fabricated, for example utilizing standard components for the ICV, and including either a high or low profile upper sleeve, and further including an inverted weld pad.
Next at Block 206, the ICV assembly is located inside the fuel tank so that the upper sleeve is aligned with the spout passage, as generally shown at FIG. 6A. For example, the ICV assembly may be passed through an opening in the tank shell, such as through opening 154 of FIG. 6A.
At Block 208, a welding apparatus arm is inserted into the fuel tank, as for example through opening 154 of FIG. 6A, and heat is applied to both the weld pad of the ICV assembly and the internal mounting surface of the tank shell.
Upon completion of the heating of Block 208, then at Block 210, the welding apparatus arm effects to press the annular flange of the ICV housing toward the tank shell, whereduring the upper sleeve is received by the spout passage and the weld pad is pressed against the internal mounting surface, whereupon the ICV housing is sealingly welded to the tank shell.
With the welding apparatus, such as the robotic arm, withdrawn from the fuel tank, and the other steps of assembly of the fuel tank undertaken, at Block 214, the fuel fill pipe/hose assembly is pressed onto the shell spout (including the shell spud if the high profile sleeve is being utilized), whereupon a hose attachment mechanism, as for example the above mentioned adjustable clamp, is tightened onto the fuel fill pipe/hose assembly, to seal the fuel fill pipe/hose assembly with respect to the shell spout, and its spout spud (and the shell spud if present).
The shell and sleeve spuds include, respectively, a sealing annulus 140 a, 140 b, 140 b′ similar to the sealing annulus 40 shown at FIG. 1B, wherein the geometry of the spud may be refined via methods such as machining to ensure a best sealing fit with respect to the fuel fill pipe/hose assembly. The outer geometry of the shell spud can be, for example, generated via geometry of the blow molding tool and cooling fixture configuration, and, if necessary for more accurate geometry, refined via post blow molding methods, such as machining. In both embodiments of the present invention, the fuel fill pipe/hose assembly may include end flaring to accommodate pressing over of the shell spud (and, if present, the sleeve spud).
To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.

Claims

1. An inlet check valve assembly for internal mounting with respect to a plastic fuel tank, comprising:

an upper sleeve;

a flange having a weld pad, wherein said upper sleeve is disposed in upstanding relation to said weld pad; and

an inlet check valve connected with said flange opposite said weld pad.

2. The assembly of claim 1, further comprising a sleeve spud disposed on said upper sleeve.

3. The assembly of claim 1, further comprising a lower sleeve connected to said flange opposite said weld pad, wherein said inlet check valve is connected to said lower sleeve.

4. The assembly of claim 3, wherein said upper sleeve has a high profile, wherein said upper sleeve is longer than said lower sleeve; further comprising a sleeve spud disposed on said upper sleeve substantially adjacent a terminus thereof.

5. The assembly of claim 3, wherein said upper sleeve has a short profile, wherein said upper sleeve is shorter than said lower sleeve.

6. A fuel tank assembly, comprising:

a plastic tank shell having a spout opening, said tank shell comprising:

a shell spout integrally connected with said tank shell, said shell spout having a spout passage communicating with said spout opening, said shell spout further having a spout spud disposed on said shell spout substantially adjacent a terminus thereof, and

a mounting surface disposed at an internal surface of said tank shell adjacently circumscribing said spout opening; and

an inlet check valve assembly comprising:

an upper sleeve received in said shell spout passage;

a flange having a weld pad, wherein said upper sleeve is disposed in upstanding relation to said weld pad, and wherein said weld pad is sealingly welded to said mounting surface; and

an inlet check valve connected with said flange opposite said weld pad.

7. The assembly of claim 6, further comprising a fuel fill pipe/hose assembly sealingly fitted on said shell spout and said spout spud.

8. The assembly of claim 6, further comprising a sleeve spud disposed on said upper sleeve.

9. The assembly of claim 8, further comprising a fuel fill pipe/hose assembly sealingly fitted on said shell spout, on said spout spud and on said sleeve spud.

10. The assembly of claim 6, further comprising a lower sleeve connected to said flange opposite said weld pad, wherein said inlet check valve is connected to said lower sleeve; further comprising a sleeve spud disposed on said upper sleeve substantially at a terminus thereof, wherein said upper sleeve has a high profile such that said sleeve spud is exposed with respect to said shell spout.

11. The assembly of claim 10, further comprising a fuel fill pipe/hose assembly sealingly fitted on said shell spout, on said spout spud and on said sleeve spud.

12. The assembly of claim 6, further comprising a lower sleeve connected to said flange opposite said weld pad, wherein said inlet check valve is connected to said lower sleeve; and wherein said upper sleeve has a short profile, wherein said upper sleeve is disposed entirely within said shell spout.

13. The assembly of claim 12, further comprising a fuel fill pipe/hose assembly sealingly fitted on said shell spout and said spout spud.

14. A plastic fuel tank, comprising:

a plastic tank shell having a spout opening, said tank shell comprising:

a shell spout integrally connected with said tank shell, said shell spout having a spout passage communicating with said spout opening, said shell spout further having a spout spud disposed on said shell spout substantially adjacent a terminus thereof, and a mounting surface disposed at an internal surface of said tank shell adjacently circumscribing said spout opening.

15. A method for enabling fueling a fuel tank, comprising the steps of:

fabricating a plastic tank shell of a plastic fuel tank, wherein the tank shell includes a shell spout;

fabricating an inlet check valve assembly;

sealing the inlet check valve assembly to an internal mounting surface of the tank shell circumscribing the shell spout; and

connecting a fuel fill pipe/hose assembly in sealing relation to the shell spout.

16. The method of claim 15, wherein said step of connecting further comprises connecting the fuel fill pipe/hose assembly in sealing relation to the inlet check valve assembly.