GB2218185A

GB2218185A - Valve assembly

Info

Publication number: GB2218185A
Application number: GB8907532A
Authority: GB
Inventors: Heinz Krause; Erhard Moses
Original assignee: Kayser A & Co KG GmbH
Current assignee: Kayser A & Co KG GmbH
Priority date: 1988-04-05
Filing date: 1989-04-04
Publication date: 1989-11-08
Also published as: GB8907532D0; DE3811438C2; FR2629553A1; DE3811438A1

Description

1 1 7.

c 1 - - ' 1 - 221919.5 VALVE ASSEMBLY The invention relates to a valve assembly for closing the vent line of a fuel tank, in which the vent line is connected to an activated charcoal filter.

Mechanically operable valves for closing the vent line when refuelling a motor vehicle having an Otto engine are known. The vent line must be closed during refuelling, so that-a safety air cushion can form in the tank, which is used for disconnecting a filling means. As a rule such valves are operated via the tank cap, i.e. when the tank cap is removed from the tank, the vent line is closed, and the valve is opened when the tank cap is placed on the tank connection and secured in place.

In order to keep the quantity of hydrocarbons discharged by the motor vehicle into the environment as low as poss ible, it is known to connect the vent line of a fuel tank to an activated charcoal filter. The activated charcoal or carbon binds the gaseous hydrocarbons, and during the running of the engine at a certain temperature part of the combustion air is passed through the activated charcoal filter, so that the hydrocarbons absorbed therein are discharged by the activated charcoal to regenerate the filter. - If the vent line remains connected to the activated charcoal filter during the refuelling of a vehicle, the filter must absorb such a large quantity of gaseous hydrocarbons from the fuel that the activated charcoal, which is normally contained in a cartridge with a capacity of roughly one litre, becomes supersaturated, and the activated charcoal filter will no longer be able to fulfil its function.

1 According to the present invention there is provided a valve assembly for closing the vent line of a fuel tank, comprising a casing with first connecting means for connection to the vent line of a fuel tank, and second connecting means for connection to a line leading to a filter, in which one connecting means has a -valve seat for a valve and in which the valve is operable by means of a push rod displaceable by a tank cap for the fuel tank.

i It is an object of the invention to provide a valve which closes the vent line during refuelling and interrupts the connection to an activated charcoal filter.

In use, the casing is placed in the vent line leading from the fuel tank to an activated charcoal tilter, and in it is located a valve, which is constructed in such a way that during refuelling, i.e.

with the fuel tank open, the connection to the activated charcoal filter is interrupted. Simultaeeously the vnnt line is closed, so that the safety air cushion can form in the tank.

According to a preferred embodiment the valve is constructed as a rocker preloaded against the valve seat by a spring and mounted in the casing.

Preferably a packing washer is located on the valve seat or rocker so that a reliable sealing of the vent line is achieved.

According to a further development of the invention the push rod may be displaceable in a guide located on the casing and the push rod and connection are i f:

preferably circular in cross-section.

In order to ensure that no hydrocarbon-containing air-can pass out through the guide in which the push rod is displaceably held, the push rod preferably has a sealing ring.

According to a preferred embodiment bearing blocks for the rocker are shaped in the casing, the rocker is constructed approximately at its centre with lateral trunnions, the bearing surface of the push rod is rounded and bears on the top of the rocker, and shaped parts for locating a spring are provided on the rocker and the inner face of the cover wall of the casing, the spring biassing the valve against the valve seat.

Preferably on an outer side of the casing are formed T-shaped undercut grooves for receiving lugs for fixing the valve assembly to a filling conduit of the tank. However, the valve assembly can also be fixed to the tank connection by screwing or pipe clips and the like.

In accordance with the invention in another aspect there is provided a valve assembly for closing the vent line of a fuel tank during filling of the tank, comprising a casing having first connecting means for connection to a vent line of a fuel tank and second c onnecting means for connection to a line leading to an air filter, the casing having a valve for controlling communication between the first and second connecting means, and the-valve being oper able by a push rod protruding from the casing and displaceable by a tank cap for closure of the fuel tank.

r i - - 4 - Preferably the said valve cooperates with a valve seat at the opening of the first connecting means into the casing.

Also preferably the push rod is moveable in an aperture in the casing with a pressure seal between the push rod and the casing.

Conveniently the valve is formed on one end of a rocker which is pivotable within the housing, the saidone end of the rocker being biassed towards the valve seat, and 4Che push rod being arranged to bear against the other end of the rocker to pivot the rocker away from the valve seat upon depression of the push rod into the casing.

In accordance with a further aspect of the invention, there is provided a valve assembly comprising a casing having first connecting means connected to a vent line of a fuel tank and second connecting means connected to a line leading to an air filter, the casing having a valve controlling communication between the first and second connecting means, the valve being operable so as to be open when the fuel tank is closed, and to be closed when the tank is open for refuelling.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 shows a valve assembly embodying the invention in longitudinal section along lines I-I of Figure 2; Figure 2 shows the valve assembly in cross-section along the lines II-II of Figure 1; and Figure 3 shows the valve assembly of Figures 1 and 2, in side view, when fixed to a tank filling conduit.

Figure 1 shows a valve assembly 10 in longitudinal section. Valve assembly 10 has a casing 11 comprising a lower casing part 12 and an upper casing part or cover 14. Casing 11 is preferably made from plastic and halves 12 and 14 are interconnected by appropriate types of connection, such as ultrasonic welding, bonding, etc.

A supply connection 16 and a discharge connection 18 are shaped onto the lower casing half 12. The vent line from a fuel tank is fixed to connection 16. A line leading to a not shown activated charcoal filter is fixed to connection 18. A cylindrical guide or connection 20 in which is displaceably guided a push roa 22 is shaped onto the upper casing half 14. An 0-ring 24 seals push rod 22 in cylindrical connection 20. Push rod 22 has a cross- sectionally thicker end 26 in the interior of the casing, so that the push rod 22 cannot be drawn out of the latter. The upper end of push rod 22 projects above the cylindrical connection 20, so that by for example engaging a tank cap within connection 20 the push rod 22 can be moved into the casing.

Within the casing 11 are shaped bearing blocks 28, 30, which have Ushaped recesses 32 with a rounded-'base at the upper end. Bearing blocks 28, 30 are used for mounting a rocker 34 which, considered in plan view, is constructed in roughly bone-like manner with circular thickened ends 36, 38. Roughly in the central region trunnions 40, 42 are shaped laterally onto the rocker and engage in recesses 32 in bearing blocks 28, 30 so that the rocker 34 can be pivoted in the bearing blocks.

The push rod projects with its inner rounded end 44 on the top of end 36. As a result of the rounding of the push rod end 44. it is ensured that friction between the push rod and the rocker is kept low. The opposite end 38 ot rocker 34 is constructed with a shaped part 46, which when the rocker is fitted faces a shaped part 48, shaped onto the inner face of casing part 14. Shaped parts 46, 48 serve to locate a spring 50 which is precompressed in such a way that the rocker is pressed against the inner raised edge 52 of connection 16 and simultaneously push rod 22 is moved outwards. In this position which is assumed when the tank cap is removed, the vent line from the tank is closed, so that the safety air cushion can torm in the tank and no petrol-vapour containing air can flow to the activated charcoal filter. In order to obtain good sealing between the rocker 34 constructed as a seating valve and connection 16, a packing washer 54 is provided, which can either be arranged on the terminal edge of end 52 of connection 16 or on the underside of rocker 34. Rocker 34 has a reinforcement 56 on the side engaging on connection 16.

Figure 2 shows the fixing of valve 10 to a tank connection 60. Shaped parts are provided on the outside of casing half 12. which form undercut grooves 62, 64. These undercut grooves are preferably closed on the top surtace. T-shaped fixing elements 66, 68 are located on the outside of the tank filling connection 60, so that with the aid of said undercut grooves 62, 64, the valve can be moved onto said fixing elements 66, 68. It is naturally possible to screw valve 10 to a tank connection or to tix it by means of a pipe clip or the like.

1 Figure 3 shows the valve assembly 10 on the filling conduit 60 of a fuel tank in side view. on closing the fuel tank by screwing in a tank cap (not shown), by means of a ring shaped onto the cap, the push rod 22 is moved into the interior of the casing of the valve assembly 10, so that the rocker is operated and pivoted _counter to the pressure of spring 50. The connections 16 and 18 are then connected via the casing 11 and the tank is vented to the activated carbon filter.

1 1 1

Claims

CLAIMS k 1. A valve as-sembly for closing the vent line of a fuel tank,

comprising a casing with first connecting means for connection to the vent line of a fuel tank, and second connecting means for connection to a line _leading to a filter, in which one connecting means has a valve seat for a valve and in which the valve is operable by means of a push rod displaceable by a tank cap for the fuel tank.
2. A valve assembly according to claim 1 in which the valve is constructed as a rocker mounted in the casing and preloaded by a spring against the valve seat.
3. A valve assembly according to claim 1 or 2 in which a packing washer is located on the valve seat or the rocker.
4. A valve assembly according to any one of claims 1 to 3 in which the push rod is displaceable in a guide located on-the casing.
5. A valve assembly according to claim 4in which a sealing ring is arranged on the push rod.
6. A valve assembly according to any of claims 2 to 5 in which bearing blocks for the rocker are formed in the casing, the rocker is provided approximately at its centre with lateral trunnions, a rounded bearing surface of the push rod bears against a surface of the rocker, and the rocker and an inner face of the casing are provided with shaped portions for locating a spring for biassing the valve against the valve seat.

1 A
7. A valve assembly according to any preceding claim in which there are formed on an outer side of the casing T-shaped undercut grooves for receiving lugs for fixing the valve assembly to a filling conduit of the tank.
8. A valve assembly for closing the vent line of a -fuel tank during filling of the tank, comprising a casing having first connecting means for connection to a vent line of a fuel tank and second connecting means for connection to a line leading to an air filter, the casing having a valve for controlling communication between the first and second connecting means, and the valve being operable by a push rod protruding from the casing and displaceable by a tank cap for closure of the fuel tank.
9. An assembly as claimed in claim 8 in which the said valve cooperates with a valve seat at the opening of the first connecting means into the casing.
10. -An assembly according to claim 8 or 9 in which the push rod is moveable in an aperture in the casing with'a pressure seal between the push rod and the casing.
2 'Ll. An assembly according to any ot claims 8 to 10 in which the valve is formed on one end of a rocker which is pivotable within the housing, the said one end of the rocker being biassed towards the valve seat, and the push rod being arranged to bear against the other end of 30 the rocker to pivot the rocker away from the valve seat. upon depression of the push rod into the casing.
12. A valve assembly comprising a casing having first connecting means connected to a vent line of a fuel tank 1 - 10 and second connecting means connected to a line leading to an air filter, the casing having a valve controlling communication between the first and second connecting means, the valve being operable so as to be open when the fuel tank is closed, and to be closed when the tank is open for refuelling.
13. A valve assembly substantially a_s hereinbefore described with reference to the accompanying drawings.

Published 1989 atThe Patent Office.State House, 66771 High Hoiborn, London W CIR 4TP. Further copies maybe obtained from The Patent Office.

Sales Branch, St Maxy Cray. Orpington. Rent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1/87