GB2239008A

GB2239008A - A fuel filler arrangement

Info

Publication number: GB2239008A
Application number: GB8928082A
Authority: GB
Inventors: Ronald Pardy
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1989-12-12
Filing date: 1989-12-12
Publication date: 1991-06-19
Also published as: GB8928082D0

Abstract

In a fuel filler arrangement for a motor vehicle fuel tank in which a closure is openable in two stages, performing the first stage opens a vent valve from the tank before the second stage is performed. in a preferred embodiment the closure is a flap 14 whose initial opening movement releases a valve 34 in a separate cap 16. The flap may be controlled by a remotely-openable latch 20 so that venting may occur before a driver reaches the filler. <IMAGE>

Description

A FUEL FILLER ARRANGEMENT This invention relates to a fuel filler arrangement for the fuel tank of a motor vehicle.

Under certain weather conditions, notably high ambient temperatures, vapour pressure builds up inside the fuel tank. It is known to vent the fuel tank so that excess vapour can escape, but this vent may become blocked by liquid fuel in the passage or other unforeseen circumstances which will lead to a limited pressure build up in the tank. When the fuel filler cap is removed, there will under these circumstances be a sudden outrush of fuel vapour which can be unpleasant for the person removing the cap.

According to the present invention, there is provided a fuel filler arrangement for a motor vehicle, the vehicle having a fuel tank, a fuel filler opening leading into the tank, a closure for the filler opening, a vent opening leading from the tank and a valve adapted to close the vent opening, in which arrangement the closure is adapted to be opened in two stages, and wherein performing the first opening stage of the closure opens the vent valve to vent any excess vapour pressure from the tank before the second opening stage is performed.

In this way the vented vapour can be directed away from the person opening the tank.

In a preferred embodiment, the filler arrangement is used in a vehicle which has a remote filler closure release mechanism such that when the remote filler release is operated, as a first openeing stage of the closure, venting takes place at that time before the driver of the vehicle approaches the filler opening.

In one example, the closure for the filler opening comprises a flap which controls access to a filler cap recess, and a filler cap in the recess fitted on the end of a filler neck. In this case release of the flap, which may be done remotely, opens the vent valve.

The vent opening is preferably independent from the normal vapour vent from the tank and thus, when open, provides an additional vapour vent passage from the tank. Preferably however the vent opening leads from the fuel filler pipe close to the top of this pipe.

In one preferred form, the valve is located in the fuel filler cap, and the vent opening is provided by a vapour passage through the cap.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figures la, lb and lc illustrate stages in the opening of a fuel filler arrangement in accordance with the invention; Figure 2 shows more detail of the filler arrangement of Figures 1; Figure 3 shows a second embodiment; and Figure 4 shows a third embodiment.

Figure la shows schematically a fuel filler recess 10 located in a side panel 12 of a motor vehicle and closed by a hinged flap 14. A fuel filler cap 16 is located in the recess 10 and has a valve 18 fitted on the cap. The flap 14 is held in its closed position by a latch unit 20 which has a remote release connection 22.

When the release mechanism 22 is operated to release the latch 20, the flap 14 opens in a first stage to the position shown in Figure lb, and may be urged into this position by a spring (not shown). When this happens, the valve 18 comes out of contact with the inner surface of the flap 14 and this movement of the valve can be used to open a vent passage. In the position shown in Figure lb therefore a vent opening from the fuel tank is fully open and excess gas or vapour pressure from the tank can escape. This all happens whilst the driver is still on the way from his seat where he has operated the remote release to the location of the fuel filler. By the time he reaches this location the excess pressure will have vented and the driver will then fully open the flap 14 and remove the cap 16 so that the tank can be filled.

Figure 2 shows one embodiment in more detail. The flap 14 is hinged at 24 to the vehicle body. The flap encloses a cavity or recess 10 in which a filler cap 16 is accessible, fitted on the open end of a fuel filler pipe 26. In the embodiment shown, the cap 16 is screwthreaded into the neck of the filler pipe 26 and has a seal 27.

The flap 14 is normally held in its closed position by a latch unit 20 which has a latch 28 extending through ahole in a leg 30 forming part of the flap 14. The latch unit 20 can be connected to a remote release which withdraws the latch 28, thus allowing the flap to open.

When the latch 28 is withdrawn, the flap can open until a bump on the bottom of the leg 30 comes into contact with a projection 32 at the side of the recess 10 as indicated in dotted lines in Figure 2. The flap then takes up the part open position shown in dotted lines, and a firm pull on the flap will snap the leg 30 past the projection 32 so that the flap can be fully opened. The cap 16 incorporates a vent valve at 34. The valve comprises a seat 36 in the cap interior, and a valve member 38 on a valve stem 40. The valve member 38 is normally held in contact with the seat 36 to hold the valve closed by contact between the upper end of the stem 40 with a step formation 42 on the inside of the flap 14. Thus, when the flap 14 is properly closed, the step 42 presses the valve stem 40 so that the valve member 38 closes on the seat 36 to shut off the valve.

However when the latch 28 is withdrawn and the flap 14 is able to move through its first stage of movement, the step 42 moves away from the stem 40. If there is an excess pressure inside the filler pipe 26, below the cap 16, then this pressure will bias the valve member 38 upwards so that the gas can escape through the valve.

The gas escapes into the interior of the cap 16 and then out of the cap through lateral openings 44. The gas flow is indicated by arrows in Figure 2. The valve stem 40 has lugs 46 to prevent excessive movement of the stem in the cap.

The remote release mechanism for the latch unit 20 will normally be accessible to the driver from his driving position. Operation of this control will withdraw the latch 28 so that the flap 14 is free to move. If there is excess pressure inside the filler pipe 26, then the pressure will cause the valve to open and the pressure will be vented through the lateral vents 44, as soon as the driver operates the remote release. The excess pressure will therefore have been vented before the driver actually approaches the fuel filler location, and any vapour which does need to escape from the tank will not escape in the drivers face.

Figures 3 and 4 show alternative embodiments, and in these drawings parts which correspond to parts already described with reference to Figure 2 bear the same reference numerals.

In Figure 3 the cap 16a has a valve member 38a which is biased onto the seat 36a by a helical spring 50. The other end of the helical spring is supported against a plunger 52 which projects out of the top of the cap and against the step 42. When the flap 14 is closed, the plunger 52 is pressed inwards and the compression force of the spring 50 holds the seat 38a against the seat 36a.

When the flap 14 is open, the plunger 52 is able to move upwards to the position shown in dotted lines in Figure 3. When this position is reached, the compression load exerted by the spring 50 on the valve member 38a will be substantially reduced, but in the absence of excess pressure in the filler pipe 26, the spring will retain the valve member 38a on the seat 36a. This is to ensure that if the flap 14 is not properly closed, the tank remains closed. The reduced force exerted by the spring 50 when the plunger 52 is in its "out" position will be such that it can be overcome by excess vapour pressure in the pipe 26. The pressure will lift the valve member and escape in the same manner as described with reference to Figure 2.

Figure 4 shows an embodiment where the pressure relief valve is independent of the filler cap 16b. In this case the leg 30b of the flap 14 acts against a plunger 60 which operates a valve at the end of a bypass vent passage 62. When the flap 14 is properly closed, the leg 30b will press on the plunger 60 to hold the valve closed. However when the flap 14 is released, the plunger will move (either under the force of an associated spring, or under the pressure generated by the fuel vapour) to allow the vapour to escape.

Although the invention has been described with reference to remote release fuel filler arrangements, the same principle can be adopted in other fuel filler systems where the tank is opened in two stages. For example, where a filler cap has to be first unlocked and then turned, the unlocking movement can open a valve to allow escape of vapour through passages directed away from the opening before the filler cap itself is removed in a subsequent stage.

Claims

1. A fuel filler arrangement for a motor vehicle, the vehicle having a fuel tank, a fuel filler opening leading into the tank, a closure for the filler opening, a vent opening leading from the tank and a valve adapted to close the vent opening, in which arrangement the closure is adapted to be opened in two stages, and wherein performing the first opening stage of the closure opens the vent valve to vent any excess vapour pressure from the tank before the second opening stage is performed.

2. A fuel filler arrangement as claimed in Claim 1, in a vehicle which has a remote filler closure release mechanism wherein upon operation of the remote filler release, as a first opening stage of the closure, venting takes place before the driver of the vehicle approaches the filler opening.

3. A fuel filler arrangement as claimed in any preceding claim, wherein the closure for the filler opening comprises a flap which controls access to a filler cap recess, and a filler cap in the recess fitted on the end of a filler neck.

4. A fuel filler arrangement as claimed in Claim 3, wherein release of the flap opens the vent valve.

5. A fuel filler arrangement as claimed in any preceding claim, wherein the vent opening is independent from the normal vapour vent from the tank and thus, when open, provides an additional vapour vent passage from the tank.

6. A fuel filler arrangement as claimed in any preceding claim, wherein the vent opening leads from the fuel filler pipe close to the top of this pipe.

7. A fuel filler arrangement as claimed in any preceding claim, wherein the valve is located in the fuel filler cap, and the vent opening is provided by a vapour passage through the cap.

8. A fuel filler arrangement substantially as herein described with reference to any one embodiment shown in the accompanying drawings.