Patent Description:
It is known in the field of vehicles and fuel systems, to use a filter canister (fuel vapor filter typically a fuel vapor filter) for fuel vapor exiting the fuel tank. The fuel vapor carried from the fuel system often contains an amount of fuel droplets which may have a damaging effect on the operation of the fuel vapor filter.

A wide variety of solutions has been offered to prevent the introduction of fuel droplets into the fuel vapor filter along with the fuel vapor.

One such solution is using a liquid vapor separator, for example as disclosed in <CIT> directed to an apparatus for controlling discharge of fuel vapor from within a vehicle fuel tank, which apparatus includes at least a primary and auxiliary liquid separating chamber positioned above a float chamber below a valve outlet. The apparatus includes at least one baffle arranged to intercept and direct filtered fuel droplets from the vapor flow and return the liquid fuel to the fuel tank. The primary and auxiliary liquid separation chambers and associated baffle are positioned to facilitate flow of fuel vapor from the tank yet return liquid fuel to the tank.

Another solution for dealing with the above problem, is in the form of expansion tanks, for example as discussed in <CIT> to the applicant of the present application, which discloses a fuel expansion device for a vehicle fuel tank, the device comprising a housing formed of a first housing member and a second housing member, both made of an essentially impermeable material and being sealingly and impermeably attached to one another. At least one inlet port for fuel fluid ingress is formed in the first member and is in flow communication with the fuel tank, and an outlet port is formed in the second member connectable to a fuel fluid handling device.

<CIT> discloses a liquid vapor separator for a vehicle's fuel system, said liquid vapor separator comprising a body having an inlet connectable with a venting system of a fuel tank and a vapor outlet connectable to a fuel vapor treating device, and a condensation space for condensation of fuel droplets, said space being in flow communication with said inlet and with said outlet, and said condensation space extending at or being in flow communication with a filler neck of the fuel system.

<CIT> discloses a vehicle fuel accessory. In particular, it relates to a fuel vapor separation device for separating fuel vapor from liquid fuel. No fuel vapor treating device is disclosed.

In order to better understand the invention and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:.

Attention is first directed to <FIG> of the drawings, directed to a first aspect of the present disclosed subject matter, being a fuel liquid trap and generally designated <NUM>.

The liquid trap <NUM> comprises a housing generally designated <NUM> with a base <NUM>, a continuous side wall <NUM> extending therefrom and a top <NUM>, defining together a confined space designated <NUM>.

Noting the fuel accessory is a liquid separator <NUM>, it is thus configured for fitting within a vehicle's fuel tank (not shown), and it is further noted that in the present illustrated example the top <NUM> constitutes a top wall portion <NUM> of a fuel tank. However, it is appreciated that rather than constituting a top wall of a fuel tank, the top can just as well be an independent wall member extending from the side walls of the housing <NUM>, and thus the housing is configured for articulation within the fuel tank as a unitary item, i.e. not integrated with a top wall of the fuel tank, but rather attached thereto.

The base <NUM>, side wall <NUM> and top <NUM> define together a fluid-tight confined space <NUM> (<FIG>) with a liquid inlet port <NUM> extending into the confined space <NUM> at a curved side wall portion <NUM>. The liquid inlet port <NUM> extends substantially tangent to the side wall <NUM> and a flow path through the liquid inlet port merges with the wall portion <NUM> such that the flow path is minimally interrupted as it enters the confined space <NUM>, and whereby fluid ingressing through the inlet port <NUM> is caused to swirl about the inside surface <NUM> of the side walls <NUM>, as represented by arrowed line <NUM>, thus imparting the ingressing fluid a cyclonical flow pattern along the inside <NUM> surface of the side walls <NUM>. It is appreciated that the side walls of the housing may be circular or comprise at least one or more arced wall portions, which result in imparting the fluid ingressing through the inlet port <NUM> to swirl about the inside surface <NUM> of the side walls, as mentioned hereinabove.

The construction of the housing and the inlet port can be configured to allow a cyclonic separation or the fuel fluid flow such that the fuel liquid drops are separated from the fuel vapor through vortex separation. The gravity and rotational effects caused by the inlet port extending tangentially to a rounded wall portion facilitate the separation of the fuel droplets and the fuel vapor.

When the fuel flows into the confined space and follows engages the wall portion the fuel droplets in the rotating stream have too much inertia to follow the rounded wall portion, thus striking the inner surface of the wall portion. As a result, and due to the gravity the droplets fall to the bottom of the confined space. The vapor portion if the fuel, however, follows the rounded wall portion due to the relatively low destiny thereof.

It is appreciated that the wall portion <NUM> in which the inlet port merges need not be the wall portion of the housing, rather can be a wall portion which is inserted inside the confined space for the purpose of allowing the fluid ingressing through the inlet to engage it and to thereby cause a rotational effect thereof, and the cyclone separation of the fuel droplets.

The housing <NUM> is further configured at the top <NUM> with a fluid outlet port <NUM>, configured for coupling to a fuel vapor treating device (not shown), such as a canister, an expansion tank, and the like.

The fluid outlet port <NUM> is in turn is configured with an inlet opening <NUM> in the form of an annular extension extending downwards from a bottom surface <NUM> of the top <NUM> of the housing <NUM> and extending remote from the side walls <NUM> (and from the bottom surface <NUM> of the top <NUM>, owing to said annular extension <NUM>). This arrangement ensures that fluid egressing through the fluid outlet port <NUM> substantially does not drift along with it liquid droplets.

It is noted that a longitudinal axis X of the fluid outlet port <NUM> extends substantially parallel to the side walls <NUM> and normal to the top <NUM>, and further substantially normal to the longitudinal axis T of the substantially tangentially extending fluid inlet port <NUM>.

The housing <NUM> is configured at the base wall <NUM> with a liquid drain port <NUM> for draining any liquids striking the inside surface <NUM> of the side walls <NUM>, and thereby falling to the bottom of the housing. The liquid drain port is typically configured at a lowermost location of the base wall <NUM>, wherein a longitudinal axis Y of said liquid drain port extends substantially parallel to the longitudinal axis X of the fluid outlet port <NUM>, this however being a particular example only.

Furthermore, the liquid drain port <NUM> is configured with a valve <NUM> (only partially seen in <FIG>) facilitating fluid flow therethrough only in one direction so as to drain fluid from the confined space <NUM> and to prevent fluid ingress therethrough. However, it is appreciated that the valve <NUM> can be of any type, setting as an example only an inverted mushroom-type valve, a spring biased membrane, any type of valve-governed valve, e.g. a rollover valve, etc. also, the valve can be an active valve member, e.g. an active pump valve.

It is further appreciated, from <FIG>, that the confined space <NUM> is substantially homogeneous, i.e. devoid of condensation elements such as walls and ribs, whereby condensation takes place substantially over the inside surface <NUM> of the side walls <NUM> of the confined space <NUM>.

In operation, fluid vapor flows into the confined space <NUM> through the inlet port <NUM>, and is imparted a cyclonical flow pattern along the inside surface <NUM> of the side walls <NUM>, resulting in increasing liquid condensation over the inside surface <NUM>, whereby any fuel liquid droplets drain along the side walls towards the base <NUM> and then drain out through the liquid drain port <NUM>, and where fuel fluid in gas state is free to egress thorough the fluid outlet port <NUM>, substantially without any liquid droplets.

Further attention is now directed to figured 4A and 4B, illustrating another example of a liquid trap according to the present disclosed subject matter and generally designated <NUM>.

The principle differences between the example illustrated in <FIG> and those depicted in <FIG> reside in mainly in three elements. First, it is well noted that the housing <NUM> has a substantially round (circular) side wall <NUM>. Further noted is the fluid inlet port <NUM> at a lower portion thereof, i.e. near a bottom wall <NUM> thereof, and further, a longitudinal axis T of the inlet port <NUM> extends substantially tangentially into the confined space <NUM> of the housing <NUM>. Another difference resides in that the outlet port <NUM> extends from a top portion of the side wall <NUM>, however wherein the inlet opening of the outlet port <NUM> extends not near the inlet port <NUM>, and such that an axis X' of the outlet port does not coextend with the axis T of the inlet port <NUM>.

In the particular example the inlet port <NUM> and the outlet port <NUM> extend substantially normal to a longitudinal axis Y' of the housing <NUM>. Evenmore so, it is noted that the opening of the outlet port <NUM> is configured with an annular extension <NUM> extending inwardly from the side wall <NUM>. The above arrangements eliminate or substantially reduce likelihood of fuel droplets escaping through the liquid trap <NUM> into the outlet port <NUM>.

It is also noted in <FIG> that the liquid trap <NUM> is configured at a bottom thereof with a float governed valve <NUM> (setting as an example only, a rollover valve) being in flow communication with a liquid drain port <NUM> configured at a lower portion of the housing <NUM> and being in flow communication with the confined space <NUM>.

Turning now to <FIG> of the drawings directed to a to a second aspect of the present disclosed subject matter, being a liquid vapor separator (LVS) and generally designated <NUM>.

The liquid vapor separator <NUM> comprises a housing generally designated <NUM> with a base portion <NUM>, a tubular (circular) side wall <NUM> extending therefrom and a top <NUM>, defining together a confined space designated <NUM>.

Noting the fuel accessory is a liquid vapor separator <NUM>, it is thus configured for fitting on a filler neck <NUM> ('filler pipe'; a schematic portion illustrated for sake of example in <FIG>), of a vehicle's fuel tank (not shown). The liquid vapor separator <NUM> is thus configured with a flange <NUM> extending from the housing <NUM>, for sealingly welding within an opening <NUM> of the pipe section <NUM>, or otherwise attaching thereto. For example there may be a coupling pipe extending between the housing <NUM> and the filler neck <NUM>.

The base portion <NUM>, side wall <NUM> and top <NUM> define together a fluid-tight confined space <NUM> (<FIG>) configured with a liquid inlet port <NUM> extending into the confined space <NUM> at the tubular side wall <NUM>. The liquid inlet port <NUM> extends substantially tangent to the side wall <NUM> and a flow path through the liquid inlet port merges with the side wall portion <NUM>, such that the flow path is minimally interrupted as it enters the confined space <NUM>, and whereby fluid ingressing through the inlet port <NUM> is caused to swirl about the inside surface <NUM> of the side wall <NUM>, as represented by arrowed line <NUM>, thus imparting the ingressing fluid a cyclonical flow pattern along the inside surface <NUM> of the side wall <NUM>.

It is appreciated that the side walls of the housing may be circular or comprise at least one or more arced wall portions, which result in imparting the fluid ingressing through the inlet port <NUM> to swirl about the inside surface <NUM> of the side walls <NUM>, as mentioned hereinabove.

The housing <NUM> is further configured at the top <NUM> with a fluid outlet port <NUM>, configured for coupling to a fuel vapor treating device (not shown), such as a canister, and the like.

The fluid outlet port <NUM> is in turn is configured with a coupling pipe extension <NUM> and an inlet opening <NUM> in the form of an annular extension extending downwards from a bottom surface <NUM> of the top <NUM> of the housing <NUM> and extending remote from the side walls <NUM> (and from the bottom surface <NUM> of the top <NUM>, owing to said annular extension <NUM>). This arrangement ensures that fluid egressing through the fluid outlet port <NUM> substantially does not drift along with it liquid droplets.

The housing <NUM> is configured at the base wall <NUM> with a liquid drain port <NUM> for draining any liquids engaging the inside surface <NUM> of the side walls <NUM>, said liquid drain port <NUM> configured at a lowermost location of the base wall <NUM>, wherein a longitudinal axis Y of said liquid drain port <NUM> extends substantially coaxial with the longitudinal axis X of the fluid outlet port <NUM>, this however being a particular example only.

Furthermore, the liquid drain port <NUM> is configured with a normally open shutoff gate assembly generally designated <NUM>, comprising a sealing gate <NUM> pivotally articulated at <NUM> to the liquid drain port <NUM> and fitted with a filler spout engaging lever <NUM>, which is configured for pivotal displacement into a closed position upon introducing a filler spout ('filler gun'; not shown) into the filler pipe <NUM>, to thereby prevent liquid fuel and fuel vapor flow into the liquid vapor separator <NUM> during a fueling process. However, when the fueling gun is removed from the filler pipe, at the normal course of operation, facilitating fluid flow is facilitated through the liquid drain port <NUM> in direction so as to drain fluid from the confined space <NUM>.

It is further appreciated that the confined space <NUM> is substantially homogeneous, i.e. devoid of condensation elements such as walls and ribs, whereby condensation takes place substantially over the inside surface <NUM> of the side walls <NUM> of the confined space <NUM>.

In operation, fluid vapor flows into the confined space <NUM> through the inlet port <NUM>, and is imparted a cyclonical flow pattern along the inside surface <NUM> of the side walls <NUM> (illustrated by arrowed flow path <NUM>), resulting in increasing liquid condensation over the inside surface <NUM>, whereby any fuel liquid droplets drain along the side walls towards the base <NUM> and then drain out through the liquid drain port <NUM> and into the filler neck <NUM>, and where fuel fluid in gas state is free to egress thorough the fluid outlet port <NUM> and further through coupling pipe extension <NUM>, substantially without any liquid droplets.

Further attention is now directed to the modification of the liquid vapor separator <NUM> illustrated in <FIG>. In fact, the basic difference between the liquid vapor separator <NUM> (as illustrated in <FIG>) and the liquid vapor separator <NUM> resides in that the housing <NUM> has a base <NUM> terminating at an annular seat <NUM> configured for mounting over a respective opening <NUM> of a filler pipe <NUM> of a fuel tank (not shown), devoid of a shutoff gate assembly as presented in the example of <FIG>. Otherwise, structure and operation of the liquid vapor separator <NUM> is substantially similar to liquid vapor separator <NUM>, whereby fuel droplets generated over the inside surface <NUM> of the side wall <NUM> of the housing <NUM> is free to drip directly into the filler pipe <NUM> through opening <NUM>.

Claim 1:
A vehicle fuel system comprising a fuel tank configured with a fuel accessory (<NUM>) and a fuel vapor treating device, the fuel accessory (<NUM>) comprising
a housing (<NUM>) configured with a confined space (<NUM>),
at least one fluid inlet port (<NUM>) extending into said confined space (<NUM>),
at least one fluid outlet port (<NUM>) extending from said confined space (<NUM>), said at least one fluid outlet port (<NUM>) having a corresponding outlet port inlet opening (<NUM>) in said confined space, and
at least one liquid drain port (<NUM>) extending from the confined space (<NUM>),
wherein an inlet flow path defined by said inlet port (<NUM>) extends tangentially relative to a wall portion (<NUM>) in said confined space (<NUM>),
wherein the fluid inlet port (<NUM>) and the fluid outlet port (<NUM>) extend at different axial elevations within the housing (<NUM>),
wherein the at least one liquid drain port (<NUM>) extends below the at least one fluid outlet port (<NUM>),
wherein said at least one fluid inlet port (<NUM>) is axially below the outlet port inlet opening (<NUM>);
wherein said at least one fluid outlet port (<NUM>) is coupled to said fuel vapor treating device; and
wherein said at least one liquid drain port (<NUM>) is coupled to the fuel tank.