A fuel tank closure component

Abstract: A fuel tank is closed by a closure component (28) which supports the fuel pump (36), the fuel level sender (38) and fuel line connections (32, 34) to the vehicle engine. The component fits into a circular aperture (30) in the top of the tank (20). The component has a metal plate (52) and a plastics moulding (56), the plastics moulding having push-­ fit sockets (70,72,74) for receiving the ends of the fuel line connections.

Description: FIELD OF THE INVENTION This invention relates to a fuel tank and to a fuel tank closure component for completing the fuel tank. BACKGROUND OF THE INVENTION Fuel tanks for motor vehicles are conventionally manufactured as an enclosure with a filler neck extending from the enclosure and with an opening in an upper surface through which internal fuel tank components such as a fuel level sender unit and a fuel pump can be introduced into the tank. A closure component is required to close this opening once the internal components have been introduced, and also to provide passages through which fuel can flow to and from the engine. It is important that this closure component should be capable of sealing tightly with the surrounding material of the fuel tank, and that it should also be resistant to rupturing in the event of the vehicle being involved in a crash. It is known from DE-A-25 50 950 to make the closure component of metal and to fit one or two fuel pipes through the metal disk and to support them and seal them in the disk by means of soldering and by internal bracketry. Such components are however complicated to manufacture, requiring several assembly operations, and the fuel pipes passing through the component are themselves liable to damage. It is also known from DE-A-33 20 492 to close the opening with a closure component made entirely as a plastics moulding, with hoses which form the fuel line connections being pushed on to spigots moulded into the component. In order to obtain the necessary product features, such a component has to be moulded from a highly crystalline plastic, and such materials have a tendency to be brittle. Brittleness is unacceptable from the point of view of crash testing. Furthermore, the moulding of spigots to such a closure implies that the spigots are upstanding from the closure face (when they are vulnerable to impact) or are housed in recesses (where it is difficult to check that correct sealing connections have been made between the spigots and the hoses). SUMMARY OF THE INVENTION According to the present invention, there is provided a fuel tank comprising a blow-moulded tank body having top and bottom side walls defining an internal cavity for containing fuel, a fuel filler pipe communicating with the cavity, an opening in the top wall of the tank body and a closure component received in the opening to close the opening, the closure component comprising a metal plate with an aperture therethrough, characterised in that a plastics moulding is received in the aperture in the plate, the moulding including two push-fit sockets each for receiving the stem of a fuel pipe connector and the tank also including components fitted to the sockets inside the tank to prevent accidental outflow of fuel. A metal plate is used because of the inherent ductility of this material. Mild steel is suitable. If the tank is subjected to an impact which distorts the edge of the tank opening, then the plate will yield but will not fracture, and the fuel integrity of the tank will be maintained. The invention also provides a fuel tank closure component for use in a tank as set forth above. Push-fit sockets for use in fuel lines are known, and an example of such a socket is described in GB-PS 1 520 742. The main characteristic of such a push-fit socket is that the act of pushing a pipe completely into the socket completes a fluid tight joint between the tube and the socket and brings into action a mechanical lock preventing the pipe being withdrawn from the socket. The mouths of the sockets into which the fuel pipes will be pushed are preferably substantially flush with the outer surface of the component and, in use, substantially flush with the outer surface of the fuel tank. The metal plate is preferably a mild steel disc with a circular aperture, and the plastics moulding is received in the aperture. A rubber seal may be fitted between theplastics moulding and the metal plate. The metal plate preferably supports the fuel pump and the sender assembly. A securing ring arrangement comprising a ring moulded into the periphery of the opening and a separate retaining ring may be used to secure the component. In an alternative form, the plastics moulding may be simply staked into an aperture in the metal plate. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of the rear part of the car incorporating a fuel tank with a closure component in accordance with the invention; Figure 2 is a transverse section through the fuel tank shown in Figure 1; Figure 3 is a sectional view through part of the fuel tank and the closure component in accordance with the invention; Figure 4 is a view on a larger scale of part of the closure component; and Figure 5 is an exploded view of the closure component assembly. DESCRIPTION OF A PREFERRED EMBODIMENT Figure 1 shows a side view of the rear part of the car with a rear road wheel 10, a body side panel 12 and a rear floor pan 14. Forward of the rear wheel 10 is a seat 16 with a back rest 18, and located beneath the seat and beneath the floor pan 14 is a fuel tank 20. The fuel tank is connected by means of a filler pipe 22 to a filler opening 24 in the body side panel 12. The tank has a top face 26 in which a closure component 28 is mounted. The tank shown in the drawings is blow moulded from a plastics material and will be held to the under-side of the floor pan 14 by supporting straps (not shown) in a manner which is already known. The closure component 28 provides connections by which fuel feed and fuel return pipes can be connected to the tank and through which fuel can be supplied to and returned from the engine fuel system. The closure component is located in a dished area of the top surface of the tank, and the external components which extend above the top surface of the tank are housed within a space between the top 26 of the tank and the under-side of the floor pan 14. Figure 2 shows the tank on a larger scale and in transverse cross section, i.e. the section is taken in a vertical plane across the vehicle. The tank 20 is a one-piece blow moulding, with an opening at 30 for receiving a closure component 28. Externally of the tank, the closure component has two fuel pipe connections 32 and 34, and internally of the tank the closure component supports a fuel pump 36 and a fuel level sensor mechanism 38 activated by a float 40. The fuel level within the tank is shown at 42, and a reservoir 44 surrounds the bottom end of the pump 36 to provide a volume of fuel into which a filter sock 46 can extend. In the views of both Figures 1 and 2, the fuel connections 32 and 34 are housed in a shallow recess in the top face 26 of the tank, below the floor pan 14. Figure 3 is a view on a larger scale of the closure component 28. The part of the plastics fuel tank 20 which surrounds the opening 30 is illustrated in this figure, and it will be seen that a securing ring 48 is moulded into the edge of the tank opening 30, and that a separate retaining ring 50 is used to clamp in place a metal plate 52 which forms part of the component 28. A seal ring 54 is compressed between the edge of the tank and the plate 52 when the retaining ring 50 is put into place. A plastic insert 56 is fitted in the metal plate 52, into a socket formed by inturned flanges 58 on the plate, and held in place by a cover plate 60. The cover plate 60 is spot welded to the plate 52. The fuel feed and return connections 32, 34 are in the form of right-angled pipe elbows each of which has a parallel sided stem 62 to fit into a connector body 64 which is included in the insert 56. The connector body 56 is shown on a larger scale in Figure 4. This body has two pipe connectors which operate in the manner described in GB-PS 1 520 742. Each connector has a cap 66, an annular collet 68, a sleeve 70 and two O-rings 72 and 74. All these components have a passage through them for receiving a stem 62 of one of the connectors 32, 34. The plastic insert 56 also has a passage for receiving the stem which extends down to a shoulder 76 in the insert. When the stem is inserted, a fluid tight seal is formed between the outer wall of the stem and the O-rings 72, 74. The sleeve 70 has internally a sharp annular tooth or teeth 78 which makes contact with the wall of the stem. If an attempt is made to pull the stem out, then the sleeve 70 will also try to move in the outward direction because of the contact between the wall of the stem and the tooth 78. This movement will result in the lower walls of the sleeve 70 being cammed inwards by contact with the collet 68, so that the teeth 78 are pushed even further into the wall of the stem 62. The connectors can therefore not be accidentally pulled out from the passages. However if it is desired to remove a connector, then the cap 66 is lifted to raise the collet 68, and this then prevents the camming action taking place between the sleeve and the collet and allows the connector to be withdrawn. A seal 80 is fitted between the aperture in the metal plate 52 and the insert 56. In Figure 4, the right hand connector socket is for the fuel return pipe, and the socket passage ends in a non-return check valve 82 of flexible construction with a slit in it which can be opened by flow in one direction but will not be opened by flow in the other direction. The check valve is held onto the plastic insert by a retainer 84. A fuel pump inlet pipe 86 is connected by means of a seal member 88 to the bottom of the left hand connector socket, and this socket then receives the connector for the fuel feed pipe leading from the tank 20 to the engine. Figure 5 shows how the various components are assembled, with the securing ring 48 moulded into the material of the tank top 20 to form an edge to the aperture 30. The securing ring 48 has upstanding, inwardly directed lugs 90, and the plate 52 sits on an internal lip 92 (see Figure 3), with a seal 54 in place. The plate 52 is then held in place by the retaining ring ring 50 which has four cam forms around its edge so that the ring can be dropped into place on top of the plate and then rotated through the appropriate angles so that the cam forms 94 engage under the retaining lugs 90 to press the plate 52 against the seal 54. In addition to the hole in the plate 52 for receiving the insert 56, there is another hole 96 through which electrical connections will be made to the sender unit 38, but these electrical connections form no part of the present invention. To connect the fuel tank 20 to the engine of the vehicle, it is only necessary to push-fit the end of the two connectors 32, 34 into the sockets in the insert 56. Because there are no upwardly projecting parts of the closure component, the component is not vulnerable to damage prior to assembly. If the vehicle is involved in a crash which has the effect of producing relative movement between the top of the tank and the floor pan 14, which might lead to shearing off of the connectors 32, 34 across the top surface of the tank, then the tank will remain fluid-tight. The closure component as described here therefore eliminates the troublesome soldering or brazing previously used to attached fuel feed and return pipes to the top of the fuel tank.

Claims: A fuel tank comprising a blow-moulded tank body (20) having top and bottom side walls defining an internal cavity for containing fuel, a fuel filler pipe (22) communicating with the cavity, an opening (30) in the top wall of the tank body and a closure component (28) received in the opening to close the opening, the closure component comprising a metal plate (52) with an aperture therethrough, characterised in that a plastics moulding (56) is received in the aperture in the plate, the moulding including two push-fit sockets (64) each for receiving the stem (62) of a fuel pipe connector (32,34) and the tank also including components (36,82) fitted to the sockets inside the tank to prevent accidental outflow of fuel. A fuel tank as claimed in Claim 1, wherein the metal plate (52) supports a fuel level sensor mechanism (38) located inside the tank. A fuel tank as claimed in Claim 1 or Claim 2, wherein the metal plate (52) is of mild steel. A fuel tank as claimed in any preceding claim, wherein the sockets (64) have mouths into which the fuel pipes (62) will be pushed and the mouths are substantially flush with the outer surface of the component (28) and substantially flush with the outer surface of the fuel tank (20). A fuel tank as claimed in any preceding claim, wherein the metal plate (52) is a disc with a circular periphery and a circular aperture, and the plastics moulding (56) is received in the aperture. A fuel tank as claimed in any preceding claim, wherein a securing ring (48) is moulded into the tank (20) around the opening (30) in the top wall of the tank, the ring has upstanding lugs (90) projecting in a direction outwardly of the tank, and a retaining ring (50) is provided which has a peripheral form which fits within and engages with the lugs to secure the plate (52) in the opening. A fuel tank as claimed in Claim 6, wherein the retaining ring (50) has axially directed cam forms (94) which engage with the lugs (90) on the securing ring (48) when the retaining ring is turned relative to the securing ring to exert a securing force on the metal plate (52).

Inventors: BANSE PERMJIT SINGH, BANSE, PERMJIT SINGH
Applicants: FORD FRANCE, FORD MOTOR CO, FORD WERKE AG, FORD FRANCE S. A., FORD MOTOR COMPANY LIMITED, FORD-WERKE AKTIENGESELLSCHAFT
Application year: 1990
Main classification: B60K15
IPC codes: B60K15