WO2008002207A1

WO2008002207A1 - A vehicle chassis frame

Info

Publication number: WO2008002207A1
Application number: PCT/SE2006/000797
Authority: WO
Inventors: Bengt Terborn; Bengt KÖLQVIST
Original assignee: Volvo Lastvagnar Ab
Priority date: 2006-06-28
Filing date: 2006-06-28
Publication date: 2008-01-03

Abstract

A vehicle chassis frame (10) comprising a first supporting beam unit (11) and a second supporting beam unit (12) which are arranged on opposite sides of a longitudinal centre line (13) of the frame and extend substantially in parallel with said longitudinal centre line (13). The first supporting beam unit (11) and the second supporting beam unit (12) are arranged laterally spaced apart from each other with a distance (14) being equal to or exceeding the maximum lateral wheel distance (15) of the vehicle intended to be formed by means of the vehicle chassis frame (10). The distance (14) between the first and second beam units (11 , 12) is equal to or exceeds the maximum lateral wheel distance (15) in at least a portion (16) of the vehicle chassis frame which portion is located in an area (17) where wheels (18) are to be suspended from the vehicle chassis frame (10).

Description

A VEHICLE CHASSIS FRAME

TECHNICAL FIELD

The invention relates to a vehicle chassis frame according to the preamble of claim 1. The invention is primarily applicable on trucks, in particular platform vehicles, and busses.

BACKGROUND OF THE INVENTION

Usually the frame of a truck has two main rails arranged along the chassis length. In such a design called double frame rail, the rails are centrally placed with a normal distance of 800-900 mm between the rails. The rails are usually U-profiles arranged with the flanges directed inwardly. This very common frame design is flexible or in other words; the frame has relatively low torsional rigidity which counteracts damage of the vehicle during driving on a bumpy and rough road.

However, such a prior art frame design has drawbacks due to large bending moments in the frame. Bending forces are caused by the vehicle body arranged on the frame, the load carried by the vehicle as well as by additional equipment arranged in the frame, such as fuel tank, batteries etc. These additional equipments supported by the frame are arranged outwardly the rails in the areas between the rails and the outer periphery of the vehicle. The laterally displacement of such equipment relative to the frame implies a relatively long lever arm extending between the centre of gravity of for example a fuel tank and the position where the fuel tank is supported by the double frame rail. This in turn results in undesired bending forces which act on the frame.

Due to the size of the bending moments caused by loads acting through lever arms which extend in the lateral direction of the vehicle and the distribution of the bending moments in a cross section of the frame, the double frame rail design of today has to be provided with a lot of reinforcements in the shape of cross members and brackets to support the entire loaded area covering the maximum vehicle width. These cross members and brackets have to be dimensioned for the current bending forces and bending moments. Consequently, the frame tends to be heavy and associated with high costs. Furthermore, a truck of today, which has a transmission system where the rear axle and the driveline, which extends between the engine and the rear gear house, are arranged in the frame via the spring suspension system, requires a certain minimum wheel base so as to not exceed the allowed angle of inclination of the driveline.

SUMMARY OF THE INVENTION

An object of the invention is to provide a vehicle chassis frame of the kind referred to in the introduction where at least some of the problems of such prior art vehicle chassis frames discussed above is reduced to a substantial extent.

The object is achieved by a vehicle chassis frame according to claim 1.

By the provision of a first supporting beam unit and a second supporting beam unit which are arranged laterally spaced apart from each other with a distance being equal to or exceeding the maximum lateral wheel distance of the vehicle intended to be formed by means of the vehicle chassis frame, and wherein said distance between the first and second beam units is equal to or exceeds the maximum lateral wheel distance in at least a portion of the vehicle chassis frame length which portion is located in an area where wheels are to be suspended from the vehicle chassis frame, it is possible to obtain a more favourable load distribution. Due to the improved load distribution the first and second beam units can be designed with reduced weight and/or height. This in turn implies the chassis frame can have reduced weight enabling the truck to carry more load and/or to be designed with a relatively low platform and thereby an increased cargo space. Also the packaging area or space which can be used for the additional equipments is increased.

The increased packaging area can be used to receive a larger fuel tank for instance.

By providing possible outer suspension positions for the wheels, such a vehicle chassis frame enables a wheel suspension system where each wheel is separately connected to the spring suspension.

In a preferred embodiment of the invention the frame comprises a third supporting beam unit arranged between the first supporting beam unit and the second supporting beam unit. The combination of a third supporting beam unit and the first and second supporting beam units enables an even more favourable load distribution. In an embodiment where the third supporting beam unit is arranged along the longitudinal centre line of the frame, there is still an increased packaging area between the third supporting beam unit and the first/second supporting beam unit.

The use of a third supporting beam implies that a rear gear house and a driveline extending between an engine and the rear gear house can be fixedly attached to the vehicle chassis frame. This in turn will reduce the vibrations from the driveline in comparison with a driveline which together with a rear axle is connected to the frame via the spring suspension system. Furthermore, if the driveline is fixedly attached to the frame the wheel base of the vehicle is not limited to any minimum value of the angle of inclination of the driveline, and, thus the wheel base be can be reduced if desired.

The invention relates also to a vehicle, in particular a platform truck, comprising a vehicle chassis frame according to the invention.

Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples.

In the drawings:

Fig. 1 is a schematic rear view illustrating a truck chassis frame according to prior art,

Fig. 2 is a schematic top view illustrating a vehicle chassis frame according to the invention,

Fig. 3 is a schematic lateral view of the vehicle chassis frame in figure 2,

Fig. 4 is a schematic rear view of the vehicle chassis frame in figure 2, Fig. 5 is a view corresponding to Fig. 2 illustrating an alternative embodiment of the vehicle chassis frame according to the invention,

Fig. 6 is a view corresponding to Fig. 2 illustrating a further alternative embodiment of the vehicle chassis frame according to the invention,

Fig. 7 is a view corresponding to Fig. 2 illustrating a further alternative embodiment of the vehicle chassis frame according to the invention, and

Fig. 8 is a view corresponding to Fig. 2 illustrating a further alternative embodiment of the vehicle chassis frame according to the invention, and

Fig. 9 is a view corresponding to Fig. 2 illustrating a further alternative embodiment of the vehicle chassis frame according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Fig. 1 is a schematic rear view illustrating a truck chassis frame according to prior art. Two main rails 1 , 2 shown in cross section are arranged between the left and right wheel sets 3, 4 and along the chassis length. Accordingly, the distance between the rails 1 , 2 is less than the maximum lateral wheel distance. The rails 1 , 2 are connected to a rear axle 5 via a spring suspension system 6. The entire rear axle 5 provided with a rear gear house 7, and wheel sets 3, 4, and one end of a driveline 8 extending between an engine (not shown) and the rear gear house 7, are suspended from the rails 1, 2 via the spring suspension system 6. A platform 9 is arranged on top of the rails 1 , 2.

Fig. 2 is a schematic top view of a vehicle chassis frame 10 according to the invention. The vehicle chassis frame comprises a first supporting beam unit 11 and a second supporting beam unit 12. The first and second supporting beam units 11 , 12 are arranged on opposite sides of a longitudinal centre line 13 of the frame and extend substantially in parallel with said longitudinal centre line.

According to the invention, the first supporting beam unit 11 and the second supporting beam unit 12 are arranged laterally spaced apart from each other with a distance 14 which is equal to or exceeds the maximum lateral wheel distance 15 of the vehicle intended to be formed by means of the vehicle chassis frame 10. By the expression "maximum lateral wheel distance" is meant the largest distance between the outermost wheels of the vehicle to be formed by the vehicle chassis frame 10. In other words; the first supporting beam unit 11 is arranged outside the axial periphery surface 20 of the outermost left wheel, and the second supporting beam unit 12 is arranged outside the axial periphery surface 20b of the outermost right wheel, where the left wheel and the right wheel are arranged at the same geometrical axis 45. The greatest distance 14 between the first and second supporting beam units 11, 12 is equal to or exceeds the maximum lateral wheel distance 15 in at least a portion 16 of the wheel chassis frame which portion is located in an area 17 where wheels 18 are to be suspended from the vehicle chassis frame 10. Usually, a truck has at least one such area 17 intended for rear wheels 18 and another such area 17b intended for front wheels 18b. Preferably, the inside measurement 14b between the first and second supporting beam units 11, 12 is equal to or exceeds the maximum lateral distance 15. In such a case the supporting beam units can extend outside the wheels at the same level or height as the wheels as illustrated for example in figures 2, 3 and 4.

The expression "supporting beam unit" is meant to comprise single rails, bars, beams or similar as well as two or more rails arranged relatively close to each other to form a frame construction. Although the first and second supporting beam units are constituted by U- beams in the illustrated embodiments, within the scope of the invention the rails can of course be designed differently. Different types of beams can be used and the cross section of the supporting beam unit can be varied. The first and second supporting beam units 11 , 12 are main supporting beam units which contribute considerably to the strength of the vehicle chassis frame and carry for example a platform and load applied thereon and a vehicle body, and any other additional equipment arranged on the frame.

In the embodiment illustrated in figure 2, the first supporting beam unit 11 and the second supporting beam unit 12 are laterally spaced in opposite directions by substantially equal distances 21 relative to said longitudinal centre line 13. This implies that in a front portion/rear portion of the frame the first and second supporting beam units 11, 12 are arranged laterally spaced apart from the longitudinal centre line 13 while enabling a left front wheel/rear wheel of a vehicle to be arranged between the longitudinal centre line 13 and the first supporting beam unit 11 , and a right front wheel/rear wheel to be arranged between the longitudinal centre line 13 and the second supporting beam unit 12. Furthermore, in figure 2, two different embodiments of possible front wheel sets are illustrated. On the left side a first embodiment having two front wheels arranged in front of each other (which wheel set is to be arranged on each side of the vehicle) is illustrated, and on the right side another embodiment having one front wheel (which wheel set is to be arranged on each side of the vehicle) is illustrated.

Along at least a portion of the vehicle chassis frame length, the first and second supporting beam units 11 , 12 can be the outermost arranged supporting beam units of the frame, and thereby determine the outer periphery of the frame in said at least one portion. This implies that the first and second beam units can preferably be arranged at the vehicle outer limitation, i.e. the distance between the first and second supporting beam units corresponds to the platform width. The distance 14 between the first and second supporting beam unit is then of course adapted to the current vehicle and any regulations related to the width of the vehicle. In some cases the distance 14 is suitably in the interval 2450-2650 mm, and preferably the distance is about 2550 mm.

The distance 14 between the first and second supporting beam units 11, 12 is preferably longer than the maximum lateral wheel distance 15 of the vehicle to be formed by the vehicle chassis frame 10, along a major part of the length of the vehicle chassis frame 10. In a preferred embodiment the distance between the first and second supporting beam units can exceed the maximum lateral wheel distance 15 along substantially the entire length of the vehicle chassis frame 10.

Advantageously, the frame comprises a third supporting beam unit 22 arranged between the first supporting beam unit 11 and the second supporting beam unit 12. The third supporting beam unit 22 can suitably extend substantially in parallel with and along said longitudinal centre line 13 of the frame. The third supporting beam unit 22 is a main supporting beam unit which also contributes considerably to the strength of the formed triple frame and carries weight of the platform, body and additional equipment of the vehicle. By the use of a triple frame having three supporting beam units, i.e. said first, second and third supporting beam units, a very favourable load distribution can be obtained. Furthermore, the third supporting beam unit 22 can have means 23 for suspension of a driveline 24 extending between an engine 25 and for example a rear gear house 46 of a vehicle such that the driveline 24 is fixedly attachable to the third supporting beam unit 22 and thereby to the frame. Such means 23 can be conventional brackets, attachments or similar. See also figure 4. By "fixedly attached" is meant directly connected to without any spring suspension means 26 arranged therebetween. Furthermore, the third beam unit 22 can have means 27 for suspension of an engine 25. Such means 27 can be conventional brackets, attachments or similar.

The first supporting beam unit 11 and the second supporting beam unit 12 are preferably interconnected to each other by means of one or more cross bars 28. In a preferred embodiment of the invention a front portion 29 of the vehicle chassis frame 10 has a square or box configuration enabling front wheels 18b of a vehicle to be received within the square configuration. The square configuration can contribute to improved strength of the frame, and can enable a cab to be attached to the frame in a stable way and can further provide wheel suspension positions 30. Two said cross bars 28, for example U- irons extending between the first and the second beam units 11, 12, together with the front portions 31, 32 of the first and second supporting beam unit can form the front square configuration. Possible positions 40 for arrangement of a cab 41 are schematically indicated by circles. See also figure 3.

In the same way a rear portion 33 of the frame can have a square configuration enabling rear wheels 18 of a vehicle to be received within the square configuration. Two said cross bars 28b, for example tubular square irons, together with the rear portions 34, 35 of the first and second supporting beam units 11, 12 can form the rear square configuration. Possible wheel suspension positions 30b are indicated by circles.

Also the third supporting beam unit 22 can be interconnected with the first supporting beam unit 11 and/or the second supporting beam unit 12 by means of one or more cross bars.

The first and second supporting beam units and or the cross bars can have means for suspending front wheels and/or rear wheels of a vehicle. Further alternative embodiments of the invention are illustrated in figures 5-9. The third supporting beam unit 22 can be constituted by for example a tubular square profile, two U-beams or an I-beam.

In figures 5 and 6 the third supporting beam unit is constituted by two U-beams with the flanges thereof directed away from each other. The U-beams are angled such that the beam unit has a Y-shape. The U-beams can terminate at the cross bar arranged behind the front wheels, as illustrated in figure 5, or continue substantially in parallel with the centre line 13 to the cross bar at the front end of the vehicle chassis frame as illustrated in figure 6. In figure 7 the main portion of the third beam unit is formed by a tubular square profile as illustrated in figure 2. In addition two U-beams with the flanges directed toward each other are interconnected by any coupling means or by welding to the tubular square profile and extend in the same way as in figure 6. I figure 8 the third supporting beam unit has a shape as in figure 6. Two U-beams with the flanges directed toward each other are used. In this embodiment the first and second supporting beam units 11 , 12 are terminated at the cross bar arranged behind the front wheels.

The third supporting beam unit 22 in figure 9 is constituted by two U-beams spaced apart from each other. An increased space between the U-beams implies that the vehicle frame chassis will rather comprise four supporting beam units forming a so called quattro frame. The vehicle chassis frame can comprise two or more supporting beam units, and preferably the vehicle chassis frame comprises a three or four supporting beam units.

It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.

Claims

1. A vehicle chassis frame (10) comprising a first supporting beam unit (11) and a second supporting beam unit (12) which are arranged on opposite sides of a longitudinal centre line (13) of the frame and extend substantially in parallel with said longitudinal centre line (13), characterized in that the first supporting beam unit (11) and the second supporting beam unit (12) are arranged laterally spaced apart from each other with a distance (14) being equal to or exceeding the maximum lateral wheel distance (15) of the vehicle intended to be formed by means of the vehicle chassis frame (10), said distance (14) between the first and second beam units (11, 12) being equal to or exceeding the maximum lateral wheel distance (15) in at least a portion (16) of the vehicle chassis frame which portion is located in an area (17) where wheels (18) are to be suspended from the vehicle chassis frame (10).

2. A vehicle chassis frame according to claim 1 , characterized in that said distance (14) between the first and second supporting beam units (11 , 12) is equal to or exceeds the maximum lateral wheel distance (15) along a major part of the length of the vehicle chassis frame (10).

3. A vehicle chassis frame according to claim 2, characterized in that said distance between the first and second beam units (11 , 12) is equal to or exceeds the maximum lateral wheel distance (15) along substantially the entire length of the vehicle chassis frame (10).

4. A vehicle chassis frame according to any preceding claim, characterized in that the first supporting beam unit (11) and the second supporting beam unit (12) are laterally spaced in opposite directions by substantially equal distances (21) relative to said longitudinal centre line (13).

5. A vehicle chassis frame according to any preceding claim, characterized in that the vehicle chassis frame (10) comprises a third supporting beam unit (22) arranged between the first supporting beam unit (11) and the second supporting beam unit (12).

6. A vehicle chassis frame according to claim 5, characterized in that the third supporting beam unit (22) extends substantially in parallel with said longitudinal centre line (13).

7. A vehicle chassis frame according to claim 5 or 6, characterized in that the third supporting beam unit (22) has means (23) for suspension of a driveline (24) such that the driveline (24) is fixedly attachable to the third supporting beam unit (22) and thereby to the vehicle chassis frame (10).

8. A vehicle chassis frame according to any of claims 5-7, characterized in that the third supporting beam unit (22) and the first/second supporting beam unit (11 ; 12) are interconnected to each other by means of one or more cross bars (28, 28b).

9. A vehicle chassis frame according to any of claims 5-8, characterized in that the third supporting beam unit (22) has means (27) for suspension of an engine (25) of a vehicle.

10. A vehicle chassis frame according to claim 5, characterized in that the vehicle chassis frame (10) comprises a fourth supporting beam unit arranged between the first supporting beam unit (11) and the second supporting beam unit (12).

11. A vehicle chassis frame according to any preceding claim, characterized in that a front portion (29) of the vehicle chassis frame (10) has a square configuration enabling front wheels (18b) of a vehicle to be received within the square configuration.

12. A vehicle chassis frame according to any preceding claim, characterized in that a rear portion (33) of the vehicle chassis frame (10) has a square configuration enabling rear wheels (18) of a vehicle to be received within the square configuration.

13. A vehicle chassis frame according to any preceding claim, characterized in that the first and second supporting beam units (11 , 12) have means (30) for suspension of front wheels (18b) of a vehicle.

14. A vehicle chassis frame according to any preceding claim, characterized in that the first and second supporting beam units (11 , 12) have means (30b) for suspension of rear wheels (18) of a vehicle.

15. A vehicle chassis frame according to any preceding claim, characterized in that along at least a portion of the frame length, the first and second supporting beam units (11, 12) are the outermost arranged supporting beam units of the frame, thereby determining the outer periphery of the vehicle cassis frame in said at least one portion.

16. A vehicle chassis frame according to any preceding claim, characterized in that in a front portion of the frame the first/second supporting beam unit (11 ; 12) is arranged laterally spaced apart from the longitudinal centre line (13) while enabling a front wheel (18b) of a vehicle to be arranged between the longitudinal centre line (13) and the first/second beam unit (11; 12).

17. A vehicle chassis frame according to any preceding claim, characterized in that in a rear portion of the frame the first/second supporting beam unit (11; 12) is arranged laterally spaced apart from the longitudinal centre line (13) while enabling a rear wheel (18) of a vehicle to be arranged between the longitudinal centre line (13) and the first/second beam unit (11; 12).

18. A vehicle chassis frame according to any preceding claim, characterized in that the first supporting beam unit (11) and the second supporting beam unit (12) are interconnected to each other by means of one or more cross bars (28).

19. A vehicle chassis frame according to any preceding claim, characterized in that the first and second supporting beam units (11, 12) and at least two said cross bars form a square-shaped vehicle chassis frame (10).

20. A vehicle chassis frame according to any preceding claim, characterized in that said distance (14) between the first and second supporting beam units (11, 12) substantially corresponds to the platform width of the vehicle intended to be formed by means of the vehicle chassis frame (10).

21. A truck comprising a vehicle chassis frame according to any of claims 1-20.