Fuel tank for a heavy vehicle

(54) (56) (57)

PATENT HOLDER Volvo Trucks AB, 405 08 Gothenburg SE

INVENTOR'S OFFICE NAME

Magnus Gollungberg, Myggenäs SE Albihns Patentbyrå Göteborg AB Fuel tank for heavy vehicles

CALLED PUBLICATIONS: - - SUMMARY:

The invention relates to a heavy vehicle fuel tank (1) adapted for attachment to a vehicle frame (2) via at least one support bracket (3) having a subcircular abutment surface (4) against said fuel tank, the tank (1) comprising two end wall portions (5, 6). ) and an intermediate, mainly cylindrical sheath portion (7) extending therebetween. The invention is particularly characterized in that the fuel tank (1) comprises a first substantially circular portion (8) facing the vehicle frame (8) adapted to abut against said subcircular abutment surface (4) on the support bracket (3), and a second, from the vehicle frame (2). ) reversed, substantially rectangular portion (9).

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The numbers in brackets indicate international identification code, INlD code. Letters in clamps indicate international document code.

508 530

TECHNICAL FIELD:

The present invention relates to a heavy duty fuel tank, for example a truck. In particular, the invention relates to a fuel tank of the type which is attached to a vehicle frame via at least one support bracket or the like, which extends in the longitudinal direction of the vehicle.

BACKGROUND OF THE INVENTION:

Fuel tanks for heavy vehicles, especially heavy goods vehicles, are usually mainly cylindrical in shape with two end faces an intermediate casing surface. There are two main types of fuel tanks on the market, one of which is circular cylindrical - hereinafter referred to as a circular tank and the other is rectangular cylindrical - hereinafter called a rectangular tank.

The circular tank is traditionally the dominant tank type in i.a. The United States, where the "round" tanks are considered to be a significant part of the truck's overall appearance, and therefore often chrome-plated for appearance reasons. Rectangular tanks are thus still difficult to sell in the US market, although increased use of so-called chassis skirts along the sides of the chassis - which skirts hide the tanks so that they are not visible from the sides of the vehicle - can also be noted there. The chassis skirts contribute to a reduced air resistance for the vehicle while giving it a more integrated, design-friendly visual impression. An advantage of a circular tank is that, due to its round tank bottom shape, it has a minimal residual volume, ie the volume that can never be sucked out of the tank due to the fact that the tank's fuel suction pipe is necessarily at a certain distance from the tank bottom.

A further advantage of the circular tank is that it is attached to the vehicle frame with two relatively compact - and thus weight-saving - support brackets, which also offer a good ground clearance by being constructed as a vertical cradle with a basically circular abutment surface for the tank. are provided with the fastener for straps, with the help of which the circular tank is forced into the cradles of the support brackets.

A disadvantage of the circular tank is that during the vibrations and vibrations of the drive it has a tendency to rotate in its attachment and thus expose the fuel lines and luminaires to high stresses. Many countries also require circular tanks to be supplemented with side impact protection outside the tank, against the sides of the vehicle, as it is otherwise feared that pedestrians or colliding smaller vehicles will fall under the heavy vehicle chassis in the event of an accident. However, when using rectangular tanks no one is required

508 530 side impact protection since their substantially flat sides against the sides of the vehicle are considered sufficient in this regard.

Instead, the rectangular tank is dominant in the European market, mainly because it holds a relatively larger fuel volume than the circular tank. Maximizing the tank's fuel volume is also particularly important in e.g. the European market because, according to statutory requirements, it is limited to a certain maximum permissible so-called parachute length of the vehicle, in which the vehicle cab and the load carrier part are included. Consequently, Europe is striving for the largest possible tank volume at the minimum possible vehicle length, which is the main reason why the rectangular tank is in demand to such an extent. This relationship is particularly noticeable with respect to the most common truck carrier, the semi-trailer, which consists of a tow truck and a separate load carrier part trailer. In the USA, however, the relatively smaller fuel volume of the circular tank is not as onerous as the legislative requirements there only regulate the maximum permissible length of the truck carrier itself, whereby the tank truck can easily be made longer in order to obtain the desired fuel volume. A further advantage of the rectangular tank is that, just because of its rectangular shape, it does not exhibit any tendencies to rotate in its attachment during travel, as is the case with the circular tank and mentioned above.

However, one disadvantage of the rectangular tank is that it has a relatively large residual volume due to the substantially flat tank bottom. Another disadvantage is that the tank is fitted to the vehicle frame by means of two L-shaped support brackets, which are heavier than the corresponding subcircular support brackets for a circular tank and partly result in reduced ground clearance and / or reduced fuel volume due to the L's horizontal portion, which normally has a height of approx. 10 cm. Thus, the volume-optimized visual impression of a rectangular tank compared to a circular tank is somewhat deceptive, as the corresponding 10 cm height is instead used for valuable fuel volume of the circular tank. The actual difference in fuel volume between the two tank types is thus not as great as the eye can be led to believe.

Manufacturers of heavy goods vehicles, for the above reasons, offer both rectangular and circular tanks for their vehicles, according to demand. The different tank types, as mentioned above, require completely different types of carrier brackets. In parallel, offering both circular and rectangular tanks ultimately means higher costs in both design and production for the manufacturer, compared to offering a single tank type instead.

DISCLOSURE OF THE INVENTION:

The object of the present invention is to provide a fuel tank for a heavy vehicle which offers a combination of the main advantages of both a circular and a rectangular fuel tank. Thus, the invention provides a fuel tank which holds a relatively high fuel volume, a small residual volume and a good ground clearance, while the tendencies for rotation in the attachment and the need for extra side impact protection along the sides of the tank are eliminated by the tank design.

The above object is achieved by means of a fuel tank whose characteristic features are set forth in the following claim 1. The invention thus relates to a heavy vehicle fuel tank adapted for attachment to a vehicle frame via at least one support bracket having a

508 530 partial circular abutment surface against said fuel tank, the tank comprising two end-end portions and a spacing portion thereof, which is generally cylindrical, mainly cylindrical. In particular, the invention is characterized in that the fuel tank comprises a first substantially circular portion facing the vehicle frame adapted for abutting against said subcircular abutment surface of the support bracket, and a second substantially rectangular portion facing away from the vehicle frame.

The invention also makes it possible to use the same support brackets on all vehicles, whether they are intended for markets where traditionally either circular or rectangular are in demand. Consequently, the design and production cost of the manufacturer can be substantially reduced.

Furthermore, the fuel tank according to the invention gives the same volume optimized impression as a rectangular tank, without the tank having the disadvantages of the rectangular tank.

The other features and advantages of the invention will become apparent from the following description of a preferred Embodiment and claims subject to Claim 1.

BRIEF DESCRIPTION OF DRAWING:

The invention will be described below by an embodiment with reference to the accompanying drawing, in which:

Fig. 1 is a perspective view of a fuel tank according to the invention, provided with carrier brackets and straps;

Fig. 2 shows an end view of the fuel tank according to the invention, where the tank is shown attached by support brackets and straps to a vehicle frame; and

Fig. 3 shows a schematic, comparative tank profile view, where the differences in volume between a circular tank, a rectangular tank and a tank according to the invention are illustrated.

DESCRIPTION OF THE PREFERRED EMBODIMENT:

In Figure 1, the reference numeral 1 generally denotes a fuel tank according to the invention. The fuel tank 1 consists essentially of two end-end portions 5, 6 and a spacing portion thereof, which is mainly cylindrical, 7. A filling cap 10 and a tank annulus 11, provided with e.g. the fuel line from the tank (not shown), is located in a recess 12 on the top 13 of the tank 1. Through the recess 12, the filler cap 10 and the tank luminaire 11 are positioned so that they only marginally protrude above the top of the tank 13 and are thus well protected against mechanical damage from, for example, a trailer chassis (not shown) which swings past just above said top side.

As can be clearly seen in Figure 1, the tank 1 is in a known manner intended to be attached to a vehicle frame 2 via two support brackets 3, which are mounted on the vehicle frame by means of bolted joints 17. Furthermore, the support brackets 3 are provided in known manner with fasteners for straps 15,

508 530 provided with clamping devices 16, by means of which the tank 1 is forced into subcircular abutment surfaces 4 on the support brackets. The tank 1 is normally made of steel sheet, but can also be made of other materials suitable for the purpose, such as, for example, aluminum or plastic.

The feature of the tank 1 according to the invention is that its sheath portion 7 comprises a first, substantially circular portion 8 facing the vehicle frame 2 adapted for abutment with said subcircular abutment surface 4 on the support bracket 3, and a second, substantially rectangular portion 9 turned away from the vehicle frame 2. 1 and FIG. 2 For the sake of clarity, a dividing line 17 has been drawn between the subcircular portion and the rectangular portion, which dividing line is however not found on the actual tank. By the term subcircular part is here meant a part of the tank which, in profile - as seen from the gable portions 5, 6 of the tank - shows the shape of a circle sector, but not a whole circle. In the preferred embodiment shown in the figures, this semi-circular portion (8) is semi-circular. Hereby the great advantage is achieved that the tank 1 can be attached by means of support brackets of the well-known type which have long been used for the attachment of circular fuel tanks.

The special design of the tank further provides a tank bottom - generally designated by reference numeral 18 - which offers a greatly reduced residual volume compared to a traditional rectangular tank, ie the volume that can never be sucked out of the tank due to the tank 1 fuel suction pipe (not shown) by necessity is at a certain distance from the tank bottom 17.

Fig. 2 also shows a so-called chassis skirt 19, which is located in close proximity to the outside of the tank 1. The chassis skirt 19 consists of mainly vertical plastic panels 25 which extend along the sides of the vehicle and are supported by a frame 20, which is fixed in the vehicle frame. 2 using brackets not shown. It can be seen from the figure that the outside 24 of the tank 1, which is a side of the above-mentioned rectangular portion 9, is slightly arched outwards, i.e. in the direction from the vehicle frame 2, in such a way that it protrudes in the framework 20 in order to utilize an existing space 26 within the fuel volume framework 20.

The tank 1 is prevented from rotating in its attachment during driving of the vehicle by having the rectangular portion 9 having relatively sharp portion 27 relative to the subcircular portion 8, around which the straps 15 are forced to bend into shape by means of the tensioning devices 16. As can be seen in Fig. 2 27 located at the bottom and top respectively of the tank 1 outside 24. The corners 27 hereby exhibit radii of curvature, indicated in FIG. 2, which is at least 5 times smaller than the radius of curvature of the subcircular portion 8, designated R in the same figure. Preferably, the radius of curvature of the hem 27, r, is seven times less than the radius of curvature of the subcircular portion 8, R.

Fig. 3 shows schematically, in profile, the difference in fuel volume between the tank form according to the invention and the two known tank forms in directly comparable proportions and with the relative positions the fuel tanks would have if mounted in the same vehicle application. The tank according to the invention is, as before, denoted by reference numeral 1 and is shown in solid line, while a circular tank 21 is shown in dashed line and a rectangular tank 22 is shown in dotted line. It can be seen from the figure that the bottom 23 of the rectangular tank is located higher than that of the other two tanks. The reason for this is, as mentioned earlier, that the L-shaped support bracket (not shown), which is required for attaching the rectangular tank 22, steals space downwards. Thus, in order to maintain a given ground clearance, one loses in fuel volume

508 530 using a rectangular tank 22 of the traditional type shown. It is further apparent that the fuel tank 1 according to the invention has a larger fuel volume than the traditional tank. Compared to the circular tank 21, the tank 1 according to the invention has 9% greater volume, and compared to the rectangular tank, the tank 1 according to the invention has 2% larger volume. However, the rectangular tank 22 has a larger residual volume than the tank 1, so the difference in useful fuel volume is in practice about 4-5%.

The invention is not limited to the embodiments described above and illustrated in the drawings, but can be freely varied within the scope of the following claims.

508 530