GB2522543A

GB2522543A - Protective structure for protecting at least one gas tank arranged on a frame of a commercial vehicle

Info

Publication number: GB2522543A
Application number: GB1422668.2A
Authority: GB
Inventors: James Zucker; Duane Lassiter
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2014-12-18
Filing date: 2014-12-18
Publication date: 2015-07-29

Abstract

A structure 10 is provided for protecting at least one gas tank (12 see fig 2) arranged on an outer face (14 see fig 2) of a rail (16 see fig 2) of a frame (18 see fig 2) for a commercial vehicle. The protective structure 10 comprises a cage 26 bounding a receiving area 28 for the gas tank (12) and having at least two vertically spaced apart longitudinal members 30, 32 and longitudinally spaced apart vertical members 34. The longitudinal members 30, 32 are connected with each other by the vertical members 34. At least one mounting bridge 50 is for attaching the cage 26 to the rail (16) and for spanning a mounting element (48 see fig 2) attached to the rail (16). The bridge 50 is attachable to the outer face (14) of the rail (16) on both sides of the mounting element (48) with respect to the vehicle longitudinal direction. The structure 10 is for protecting the gas tank (12) whilst being low in weight.

Description

Protective Structure for protecting at least one Gas Tank arranged on a Frame of a Commercial Vehicle The invention relates to a protective structure for protecting at least one gas tank arranged on a frame for a commercial vehicle.

US 7 543 667 B2 shows a protective structure for a compressed gas storage tank of a vehicle, the protective structure comprising a plurality of storage tanks for storing a compressed gas therein, each of which includes a hemispherical dome portion formed on both ends thereof. The protective structure further comprises a plurality of panel brackets connected to both ends of the storage tanks and a plurality of pipe frames connecting edges of the panel brackets. The protective structure further comprises high pressure parts and pipes connected to the storage tanks at at least one end thereof, wherein a gas cap is attached to the outside of each of the panel brackets at both sides of the storage tanks and connected by the pipe frames to maintain the connection strength of the panel brackets.

Furthermore, US 7 624 753 B2 shows a fuel storage system for a vehicle, the fuel storage system comprising a case formed by at least two components which define an interior of said case, said interior including at least one cavity. The fuel storage system further comprises at least one pressurized storage tank positioned in a major cavity of the interior of the case. Moreover, the fuel storage system comprises a flow control device in the major cavity of the interior of the case along with the at least one storage tank with the flow control device adjacent the at least one storage tank without an intervening wall or structural member there between. The flow control device includes at least one of a pressure regulator attached to the at least one storage tank and operable to regulate the pressure of fuel supplied by the at least one storage tank and an automatically controlled valve operable to selectively allow a fuel flow from the at least one storage tank to an exterior of the case. The fuel storage system further comprises a fuel line attached to the flow control device and operable to supply fuel from the at least one storage tank, the fuel line extending from the flow control device to an exterior of the case.

It is an object of the present invention to provide a mounting structure by means of which at least ore gas tank for storing compressed gas can be protected in the event of an accident, the mounting structure having a particularly low weight.

This object is solved by a protective structure having the features of patent claim 1.

Advantageous embodiments with expedient developments of the invention are indicated in the other patent claims.

The invention relates to a protective structure for protecting at least one gas tank arranged on an outer face of a frame rail of a frame for a commercial vehicle, in particular a school bus. For example, the commercial vehicle is a type A school bus having an internal combustion engine configured to run on gaseous fuel. This means, for example, the gas tank is a compressed gas storage tank configured to store coriipressed natural gas (CNG). In order to keep the weight of the mounting structure particularly low and in order to protect the at least one gas tank in the case of an accident by means of the protective structure the protective structure comprises a cage bounding a receiving area for the gas tank. This means the gas tank can be arranged at least partially in the receiving area so that at least a portion, in particular a major portion of the gas tank is surrounded by the cage when the gas tank is arranged in the receiving space. The cage has at least two longitudinal members arranged at a distance from each other in the vertical direction of the vehicle. In other words, the longitudinal members are arranged one above the other. Moreover, the cage comprises a plurality of vertical members arranged at a distance from each other in the longitudinal direction of the vehicle, wherein the longitudinal members are connected with each other by the vertical members.

Furthermore, the mounting structure comprises at least one mounting bridge for attaching the cage to the frame rail. This means the cage can be attached to the outer face of the frame rail by means of the mounting bridge. The mounting bridge is configured to span a mounting element attached to the frame rail. Moreover, the mounting bridge is configured to be attached to the outer face of the frame rail on both sides of the mounting clement with respect to the longitudinal direction of the vehicle. The background of the invention is that, usually, a type A bus chassis has brackets attached to the outer face of the frame rail for the purpose of mounting and securing a body to the chassis. Hence, the brackets are mounting elements by means of which a body can be attached to the frame.

Additionally, there are other components such as fuel lines, emergency brake hangers, etc. that restrict available mounting locations at which the cage can be attached to the frame rail. As such, any additional items that need to be attached to the chassis, in particular the frame rail must fit around said components. Additionally, type A buses are of limited weight capacity, so any items added must not increase weight excessively.

In order to get an adequate range from a CNG powered commercial vehicle such as a bus, a large volume of tanks must be added to the vehicle. There have been a few additional approaches to achieving this result. One is to place the tanks high on the vehicle above any potential impact. Unfortunately, due to the size of the vehicle, this solution is not practical. Another solution is to place all of the tanks between frame rails of the frame, the frame rails being arranged at a distance from each other in the transverse direction of the vehicle. Once again, due to the size of the vehicle, this too is not practical as an adequate number of tanks or one tank of adequate size will not fit. This means at least one tank, i.e. the gas tank must be placed on the outside, i.e. the outer face of the frame rail. In this context the cage serves to protect the gas tank from excessive damage in the event of accidents, in particular side impacts from a large number of angles.

The traditional solution is to bolt the cage directly to the frame rail. However, this is not practical in the routine format due to the obstructions and weight challenges mentioned above. In the protective structure according to the present invention, the cage can be reinforced so that the gas tank can be protected particularly effectively. Moreover, the weight of the cage and, thus, the protective structure can be kept particularly low. In other words, the cage will not add to the weight of the commercial vehicle excessively and will still allow access to various body mounting hardware such as said mounting element which is, for example, a seat and/or track bolt.

In comparison with traditional protective structures the protective structure according to the present invention is more weight efficient for the same level of protection. Moreover, the protective structure according to the present invention can be produced without specialized tooling. It also allows for the ability to avoid existing structures so more common parts can be used without redesigning the existing vehicle. Particularly, the protective structure according to the present invention can withstand test impacts performed during crash testing of the commercial vehicle for many angles while minimizing the weight and allowing for the protected device in the form of the gas tank to be mounted around existing body hardware such as the mounting element. For example, said test impact can be a FMVSS 303 impact.

Further advantages, features, and details of the invention derive from the following description of a preferred embodiment as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and/or shown in the figures alone can be employed not in the respective indicated combination but also in any other combination are taken alone without leaving the scope of the invention.

The drawings show in: Fig. 1 a schematic perspective view of a protective structure for protecting at least one gas tank arranged on an outer face of a frame rail of a frame for a commercial vehicle; Fig. 2 a schematic perspective view of an arrangement of the protective structure on the frame rail, wherein the gas tank is arranged in a receiving area bounded by a cage of the protective structure; Fig. 3 part of a schematic perspective view of the arrangement according to Fig. 2; Fig. 4 part of a schematic perspective view of the arrangement according to Fig. 2; Fig. 5 a schematic perspective view of a mounting bridge of the protective structure; Fig. 6 a schematic and perspective top view of the protective structure; Fig. 7 a schematic perspective view of a detachable stone guard of the protective structure; and Fig. 8 a schematic and perspective bottom view of the protective structure.

In the figures the same elements or elements having the same functions are indicated by the same reference signs.

Fig. 1 shows a protective structure 10 for protecting at least one gas tank 12 (Fig. 2) arranged on an outer face 14 of a frame rail 16 of a frame 18 for a commercial vehicle such as a bus. For example, the commercial vehicle is a type A school bus comprising the frame 18. The frame 18 comprises the frame rail 16, a second frame rail 20 and a plurality of cross members 22. The frame rails 16 and 20 are arranged at a distance from each other in the transverse direction of the vehicle, wherein the frame rails 16 and 20 are connected with each other by the cross members 22 extending in the transverse direction of the vehicle.

As can be seen from Fig. 2 the gas tank 12 is attached to the frame rail 16 by means of clamps 24 attached to the outer face 14 which is also referred to as an outside of the frame rail 16. Fig. 2 shows an arrangement of the gas tank 12 and the protective structure on the frame 18, in particular the frame rail 16. The gas tank 12 is configured to store gaseous fuel in the form of compressed natural gas (CNG) by means of which an internal combustion engine of the commercial vehicle can be run. Since the gas tank 12 is arranged on the outside (outer face 14) of the frame rail 16 a particularly high volume of the gas tank 12 can be realized so that a particularly high amount of ONG can be stored in the gas tank 12. Moreover, the gas tank 12 can be mounted on the commercial vehicle, in particular the frame 18 in a particularly easy and cost-efficient way.

The protective structure 10 serves to protect the gas tank 12 from excessive damages in the event of accidents such as side impacts from any angle. For this purpose, the protective structure 10 comprises a cage 26 bounding a receiving area 28 in which at least a major portion of the gas tank 12 is arranged. In the present case, the complete gas tank 12 is arranged in the receiving area 28. In order to keep the weight of the cage 26 particularly low the cage 26 comprises longitudinal members 30 and 32 which are arranged at a distance from each other in the vertical direction of the vehicle. Moreover, the cage 26 comprises a plurality of vertical members 34 which are attached to the longitudinal members 30 and 32 on both ends so that the longitudinal members 30 and 32 are connected with each other by the vertical members 34. As can be seen from Figs. 1 and 2 the vertical members 34 are arranged at respective distances from each other in the longitudinal direction of the vehicle.

Moreover, the cage 26 comprises upper cross members 36 and 38 and lower cross members 40 and 42. The upper cross members 36 are attached to the upper longitudinal member 32 and extend away from the upper longitudinal member 32 in the transverse direction of the vehicle towards the frame rail 16. The lower cross members 40 and 42 are attached to the lower longitudinal member 30 and extend away from the lower longitudinal member 30 in the transverse direction of the vehicle towards the frame rail 16. Moreover, the cage 26 comprises vertical members 44 and 46, wherein the vertical member 44 is attached to the cross members 36 and 40 and the vertical member 46 is attached to the cross members 38 and 42 so that the cross members 36 and 40 are connected with each other by the vertical member 44 and the cross members 38 and 42 are connected with each other by the vertical member 46.

As can be seen from Figs. 2 to 4 respective mounting elements 48 are attached to the outer face 14 of the frame rail 16. For example, the mounting elements 48 are brackets in the form of so-called body brackets by means of which at least one body can be mounted on the frame 18. Since the mounting elements 48 are attached to the outer face 14 the mounting elements 48 are obstructions for mounting the cage 26 on the outer face 14. In order to still mount the cage 26 on the outer face 14 in a particularly advantageous way the protective structure 10 comprises mounting bridges 50 for attaching the cage 26 to the frame rail 16, the mounting bridges 50 being configured to span the respective mounting elements 48 attached to the frame rail 16. Moreover, the respective mounting bridge 50 is configured to be attached to the outer face 14 of the frame rail 16 on both sides of the corresponding mounting element 48 with respect to the longitudinal direction of the vehicle. In other words, the mounting bridges 50 which are also referred to as frame mounting bridges allow obstructions such as the mounting elements 48 on the frame rail 16 to be avoided but still permit a good secure attachment of the cage 26 to the frame rail 16 on its outer face 14. The mounting bridges 50 are bridge brackets allowing for a strong mounting of the cage 26 around existing body brackets such as the mounting elements 48.

As can be seen particularly well from Figs. 1 and 3 to 5 the respective mounting bridge 50 comprises a first portion 52 configured to overlap the respective corresponding mounting element 48 at least partially. Moreover, the first portion 42 is configured to be arranged at a distance from the outer face 14. Moreover, the respective mounting bridge 50 comprises at least one second portion 54 configured to span the distance between the first portion 52 and the outer face 14 at least partially and support the first portion on the outer face. As can be seen from Fig. 5 the first portion 42 is formed by a first piece in the form of a bridge body 56, wherein the second portion 54 is formed by a second piece in the form of a gusset 58. This means the bridge body 56 and the gusset 58 are separate parts of the mounting bridge 50, said parts (bridge body 56 and gusset 58) being connected with each other by welding. Preferably, said parts are made of a metallic material. Preferably, the parts of the cage 26 are joined by continuous welds.

Moreover, preferably, the gusset 58 is welded to the bridge body 56. The bridge body 56 comprises lateral flanges 60 having respective through openings 62 via which the bridge body 56 and, thus, the mounting bridge 50 can be bolted to the frame rail 16.

The respective mounting bridge 50 bounds a receiving area 64 for receiving at least a portion of the respective corresponding mounting element 48. In other words, in the arrangement shown in Figs. 2 to 4 the respective mounting elements 48 are arranged in the respective receiving areas 64 of the mounting bridges 50 at least partially. The gusset 58 bounds the receiving area 64 in the vertical direction of the vehicle towards the bottom.

The lower gusset 58 of the mounting bridge 50 plays an important role for realizing an adequate performance. The gusset 58 is a reinforcement element by means of which an excessive collapse of the mounting bridge 50 in the event of an angular impact and excessive movements can be avoided so that the cage 26 can be prevented from hitting fuel lines and tanks in the event of an impact.

As can be seen particularly well from Figs. 6 and 8 the protective structure 10 further comprises a reinforcement element in the form of an angle 66 made of a metallic material and extending across the back of the cage 26. The angle 66 is attached to the respective upper cross members 36 and 38 on both ends. The angle 66 is used to keep the rear end from pushing together and for connecting reinforcement elements in the form of gussets 68 extending in respective corner regions bounded by the angle 66 and the respective cross members 36 and 38. The angle 66 is used instead of a tube to allow for adequate clearance on all sides of the gas tank 12. In a worst case scenario, the angle 66 will deform until it hits the frame rail 16, thus allowing the gussets 68 to continue to provide support.

Furthermore, the protective structure 10 comprises a further reinforcement element in the form of a top mounted central rectangular gusset 70 attached at least to the upper longitudinal member 32, the gusset 70 extending away from the upper longitudinal member 32 in the transverse direction of the vehicle towards the frame rail 16 and, thus, the angle 66. The gusset 70 is attached to the angle 66. The top mounted central rectangular gusset 70 is used to prevent a parallelogram collapse in the event of an

S

angular impact without increasing the weight excessively and still allows body mounting hardware such as seat bolts to be accessed for maintenance and inspection. In other words, the centrally mounted horizontal gusset 70 controls deflection of the cage 26 in the event of an angular impact and allows, for example, seat mounting hardware to be reached. Especially, the gusset 70 helps prevent a collapse of the upper longitudinal member 32 in the event of an impact.

The cage 26 comprises further reinforcement elements in the form of gussets 72 extending in respective corner regions bounded by the longitudinal member 32 and the respective cross members 36 and 38. The gussets 68 are attached to the angle 66 and the cross members 36 and 38, wherein the gussets 72 are attached to the longitudinal member 32 and the cross members 36 and 38.

As can be seen from Fig. 8, the cage 26 comprises lower reinforcement elements in the form of gussets 74 extending in respective corner regions bounded by the lower longitudinal member 30 and the lower cross members 40 and 42. The gussets 74 are attached to the longitudinal member 30 and the respective cross members 40 and 42.

Moreover, the cage 26 comprises at least one guard element in the form of a stone guard 76 shown in Fig. 7, the stone guard 76 being made of a metallic material. As can be seen from Fig. 2, the stone guard 76 bounds at least a major portion of the receiving area 28 in the vertical direction of the vehicle towards the bottom thereby overlapping at least a major portion of the gas tank 12. Moreover, the stone guard 76 is detachable so it can be attached to and detached from the cage 26 in a non-destructive manner.

The detachable stone guard 76 on the bottom is stiff enough to help stiffen the cage 26 in the event of an impact but is removable for installation and service of the gas tank 12 and does not add excessively to the weight of the protective structure 10. The material of the detachable stone guard 76 must be able to deflect stones without damage so that the stone guard 76 can protect the gas tank 12 from road debris.

List of reference signs protective structure 12 gas tank 14 outer face 16 frame rail 18 frame frame rail 22 cross member 24 clamp 26 cage 28 receiving area longitudinal member 32 longitudinal member 34 vertical member 36 cross member 38 cross member cross member 42 cross member 44 vertical member 46 vertical member 48 mounting element mounting bridge 52 first portion 54 second portion 56 bridge body 58 gusset flange 62 through opening 64 receiving area 66 angle 68 gusset gusset 72 gusset 74 gusset 76 mudguard

Claims

Claims A protective structure (10) for protecting at least one gas tank (12) arranged on an outer face (14) of a frame rail (16) of a frame (18) for a commercial vehicle, the protective structure (10) comprising: -a cage (26) bounding a receiving area (28) for the gas tank (12) and having: o at least two longitudinal members (30, 32) arranged at a distance from each other in the vertical direction of the vehicle; and o a plurality of vertical members (34) arranged at a distance from each other in the longitudinal direction of the vehicle, the longitudinal members (30, 32) being connected with each other by the vertical members (34); -at least one mounting bridge (50) for attaching the cage (26) to the frame rail (16), the mounting bridge (50) being configured to span a mounting element (48) attached to the frame rail (16) and to be attached to the outer face (14) of the frame rail (16) on both sides of the mounting element (48) with respect to the longitudinal direction of the vehicle.
2. The protective structure (10) according to claim 1, wherein the mounting bridge comprises: -at least one first portion (52) configured to overlap the mounting element (48) at least partially and to be arranged at a distance from the outer face (14); and -at least one second portion (54) configured to span the distance between the first portion (52) and the outer face (14) at least partially and support the first portion (52) on the outer face (14).
3. The protective structure (10) according to claim 2, wherein the portions (52, 54) are formed by respective separate parts (56, 58) of the mounting bridge (50), the parts (56, 58) being connected with each other, in particular by welding.
4. The protective structure (10) according to any one of the preceding claims, wherein the protective structure (10) comprises at least one reinforcement element (70) attached at least to the upper longitudinal member (32), the reinforcement element (70) extending away from the upper longitudinal member (32) in the transverse direction of the vehicle.
5. The protective structure (10) according to any one of the preceding claims, wherein the protective structure (10) comprises at least one guard element (76) bounding at least a major portion of the receiving area (28) in the vertical direction of the vehicle towards the bottom.
6. The protective structure (10) according to any one of the preceding claims, wherein the protective structure (10) comprises at least two cross members (36, 38) attached to at least one of the longitudinal members (30, 32), the cross members (36, 38) being arranged at a distance from each other in the longitudinal direction of the vehicle.
7. The protective structure according to claim 6, wherein the protective structure (10) comprises at least one second reinforcement element (66) attached to the respective cross members (36, 38) and arranged at a distance from the longitudinal members (30, 32) in the transverse direction of the vehicle.