WO2005066010A1

WO2005066010A1 - Vehicle frame for a motor vehicle

Info

Publication number: WO2005066010A1
Application number: PCT/EP2004/013481
Authority: WO
Inventors: Christian Mosler
Original assignee: Daimlerchrysler Ag
Priority date: 2003-12-24
Filing date: 2004-11-27
Publication date: 2005-07-21
Also published as: DE10361290A1

Abstract

The invention relates to a vehicle frame for a motor vehicle. Said frame is configured as a ladder-type frame with a driver's-cab chassis module (1), a lowered frame section (4a, 4b), a central module (2) comprising two frame side members (6a, 6b) and a rear axle module (3). The frame side members (6a, 6b) of the central module (2) can be connected to the lowered frame section (4a, 4b) of the driver's-cab chassis module (1). The aim of the invention is to provide a motor vehicle frame with a flat construction, which is cost-effective to produce and can be easily adapted for different vehicle types. To achieve this, the rear axle module (3) has a rear axle supporting structure that is configured as a sub-assembly and comprises two frame side members (8a, 8b), a transversal tube (9), on the left and right of which a respective trailing arm or semi-trailing arm (24a, 24b) is mounted and an axle cross member (23).

Description

Vehicle frame for a motor vehicle

The invention relates to a vehicle frame for a motor vehicle according to the preamble of claim 1.

A vehicle frame, in particular for buses, is known from the generic document DE 31 51 280 AI, which is formed from a front frame end part, a rear frame end part and a frame middle part lying lower than this. The frame end parts are provided with vertically extending struts, which for the connection of the frame middle part have connection points lying in the plane thereof, with the exception of an upper frame part or a floor frame.

The object of the invention is to present a flat frame for a motor vehicle, which can be produced inexpensively and can be easily varied for different vehicle types.

This object is achieved according to the invention by a device with the features of claim 1.

According to the invention, the object is achieved in that the rear axle module has a rear axle support structure designed as an assembly, with two frame side members, a cross tube on the left and right each of a trailing arm. the semi-trailing arm is mounted and an axle cross member. The grouping of some components into fixed assemblies has the advantage that the assembly can be installed in different vehicle frames without changes. For example, holes and fastenings for the assembly can be made the same for all frame variants. This allows a large variety of frames, reduces the variety of components and reduces the development and assembly costs. The vehicle frame according to the invention is particularly suitable for mobile homes and vehicles with low-floor box bodies. When such vehicles are loaded, the main load lies on the rear axle. The rear axle must therefore be designed to be particularly resilient. The assembly according to the invention is self-supporting and therefore particularly stable.

In one embodiment, the rear axle support structure is designed as a preassembled module that can be inserted into the vehicle frame. This enables the module to be manufactured separately. Since the module can be used for different vehicle frames, it can be pre-produced independently of the frame production. Another advantage is that the pre-assembled assembly can be inserted into the already assembled lead frame and connected to the lead frame.

In a preferred embodiment, the rear axle module has stiffening struts which connect the cross tube to the frame side members and / or a further cross member. This results in a stable triangular lattice network. This triangular mesh is particularly torsionally rigid. This is particularly advantageous if the rear axle is driven, which means that result in additional torsional loads on the rear vehicle frame.

In an alternative embodiment, a further rear axle is provided. This has the advantage that the rear axle load can be distributed over two axles. This additional rear axle is preferably designed as a non-driven trailing arm axle.

In a particularly preferred embodiment, a multi-part propeller shaft is provided for a rear-wheel drive. As already explained, the rear-wheel drive is particularly advantageous for motorhomes, since the main load of the loaded motorhome lies on the rear axle. For a motorhome or vehicles with a similar load distribution, where the greatest load lies in the vehicle body and not in the cab, the advantage of a rear-wheel drive is the good traction due to the load distribution. This applies particularly when such vehicles have to maneuver on unpaved ground. Associated with this is the better suitability of the rear-wheel drive for trailer operation in the corresponding case.

A multi-part PTO shaft has the advantage that only one of the PTO shaft parts needs to be replaced to display vehicle frames of different lengths and different wheelbases. The bearing points on the vehicle can be selected the same for different cardan shafts.

In a preferred embodiment, the multi-part drive shaft has a front drive shaft part with two constant velocity joints. This means that the level differences of the PTO shaft caused by the lowering of the frame can be avoided Overcome the use of an expensive and in particular also heavy differential gear. The rear of the two constant velocity joints is preferably seated on a cross member shortly before the frame is lowered. This cross member also stabilizes the area of the frame lowering.

In a favorable embodiment, the multi-part drive shaft has a rear drive shaft part with two universal joints. Universal joints are less expensive than constant velocity joints. However, they can only be used to a limited extent if the drive shaft parts are not aligned with one another, but are at an angle to one another. An advantageous solution according to the invention therefore uses the inexpensive universal joints in the front area to overcome the level difference caused by the lowering of the frame, and in the rear area, where the frame level generally remains the same.

In an alternative embodiment, the multi-part drive shaft has a rear drive shaft part with two constant velocity joints. This means that an angle between the propeller shaft parts can also be compensated for at this point. This can be necessary, for example, if the frame drop is very large.

In a further embodiment, the two longitudinal frame members of the rear axle module each have a frame beam with a passage for a wheel drive shaft. The two frame side members are connected to each other via a cross tube, to which the differential of the driven rear axle is attached via a holder. The frame side members each have a passage for the wheel drive shafts emanating from the differential. The frame beam is located below the passage for the wheel drive shaft. The frame beam is used to compensate for the weakness of the frame girder caused by the passage. A passage for the wheel drive shafts can thus be represented without the frame being weakened at this point.

Further refinements of the invention emerge from the description and the drawings. Exemplary embodiments of the invention are shown in simplified form in the drawings and are explained in more detail in the description below. Show:

1 shows a vehicle frame in a perspective overall view,

2 is a detailed perspective view of a rear axle module integrated in a vehicle frame,

3 shows a perspective view of a carrier arrangement of a rear axle module with stiffening struts,

Fig. 4 cut a vehicle frame in side view.

1 shows a vehicle frame of a motor vehicle. The vehicle frame shown is designed as a lead frame. Such a lead frame consists of longitudinal frame members which are connected to one another via cross members. The ladder frame shown in FIG. 1 has three sections, a cab substructure module 1, to which a middle module 2 connects, which is connected to a rear axle module 3.

The cab substructure module 1 has a cross member 33 in the rear area, which supports the frame side members of the driver substructure module 1 connects. This cross member 33 is used to stabilize the lead frame and to support and attach the rear wall of the cab 25 (Fig. 4). In Fig. 1, a further cross member 5 is arranged just behind the cross member 33. It serves to reinforce the transition area between the cab base module 1 and the middle module 2.

In the transition area between the cab substructure module 1 and the middle module 2, the two frame longitudinal members of the cab substructure module 1, as shown in FIGS. 1 and 4, have a frame lowering 4a or 4b. In the embodiment shown, the frame lowering 4a, 4b is designed in such a way that the horizontal frame longitudinal member of the cab substructure module 1 bends downward in the direction of the central module 2 and then bends back into the horizontal with an opposite bend. The frame lowering 4a, 4b can also be designed as a slope or as an S-shaped bend. It is the task of the frame countersink 4a, 4b to connect the cab substructure module 1 to the lower-lying middle module 2. The frame lowering makes it possible to display a flat vehicle frame with a double floor. The frame lowering located behind the driver's cab is designed so that the upper part of the double floor can be arranged at the same height as the driver's cab floor and forms a flat floor surface with it. This creates a double floor as storage space from the end of the cab to the end of the vehicle, without the vehicle being built higher and its center of gravity unfavorably shifted. This lowering of the frame also enables a low side entry into the vehicle body, as is advantageous in a motor home. 1, the middle module 2 is formed with two frame longitudinal members 6a, 6b, the frame longitudinal member 6a being connected to the frame lowering 4a and the frame longitudinal member 6b being connected to the frame lowering 4b of the cab substructure module 1. The frame side members 6a, 6b are connected to one another via a cross member 7 and possibly also the cross member 5.

In the vicinity of the cross members 5 and 7, two tank holders 28a and 28b are arranged on the outside of the frame side member 6b. 1, the tank holders 28a and 28b are designed in such a way that the flanged edge of the tank 27 can be pushed into guide grooves of the tank holders 28a, 28b and is guided therein.

An exhaust system 26 is arranged between the longitudinal frame members 6a and 6b.

In the form shown in FIGS. 1 and 2, the frame side members 6a and 6b are continuous up to the rear end of the vehicle frame. In the area behind the cross member 7, the rear axle module 3 is fastened to the frame side members 6a and 6b.

Where the rear axle module 3 is arranged on the frame side members 6a and 6b, the frame side members 6a and 6b, in the embodiment shown in FIG. 2, have recesses. 2, these recesses are provided where a cross tube 9 and a passage 31a or 31b of the rear axle module 3 are positioned when the rear axle module 3 is inserted.

In an alternative embodiment, the frame side members 6a, 6b are interrupted in the area of the rear axle module 3. In a further embodiment, the frame side members 6a and 6b end where they are connected to the front end of the frame side members 8a, 8b.

2 shows the rear axle module 3 with two frame side members 8a and 8b, the frame side member 8a being connected to the frame side member 6a and the frame side member 8a being connected to the frame side member 6b. The frame side members 8a and 8b are connected to one another via the cross tube 9, the cross member 10, the axle girder 23 and the cross member 32. The cross tube 9 and the axle cross member 23 are essential. The crossbeams 10 and 32, on the other hand, serve for additional stabilization and can, if necessary, be taken by other measures such as a more powerful axle cross member 23 to be replaced.

Brackets for fastening two semi-trailing arms 24a, 24b are arranged on the cross tube 9 (FIGS. 1 and 2). The trailing arms 24a, 24b have in their rear area a spring mount, a wheel carrier and a fastening for a shock absorber.

The spring arranged in the spring holder is supported on a spring holder at the top. 1 and 2, the spring holder is designed as a bent sheet metal which is fastened to the frame side member 8a or 8b. At this height, the frame side members 8a and 8b are connected to one another by the axle cross member 23. The spring holder is arranged in the extension of this axle cross member 23.

The upper part of the shock absorber is attached to the frame side member 8a or 8b via a shock absorber holder. The shock absorber bracket is arranged in an extension of the cross member 10.

In the embodiment shown in FIGS. 1 and 2, an additional cross member 32 is arranged behind the axle cross member 23. This further cross member 32 serves to additionally reinforce the rear axle area.

In a special embodiment, as shown in FIG. 1, a further rear axle 30 is provided, to which a second pair of rear wheels are assigned. The rear axle 30 shown in FIG. 1 is a trailing arm axle.

3 shows a variant of the rear axle module 3 with stiffening struts 11. The cross tube 9 is connected to the frame side members 8a and 8b at the level of the cross member 10 by means of stiffening struts 11 designed as cross struts. Together with the cross member 10, this results in a particularly horizontally rigid lattice structure. This stiffens the lead frame against parallel displacements. The advantage of this arrangement is a reinforcement of the particularly stressed area of the rear axle. This is particularly advantageous in the case of a driven rear axle, since in this case the load on the rear axle area is further increased by the action of the driving forces.

In the embodiment shown in Fig. 3, the stiffening struts 11 are Y-shaped. A comparable effect is achieved if the stiffening struts 11 are V-shaped. In an alternative embodiment, the stiffening struts 11 are designed as straight struts which are arranged in a v or x shape with respect to one another.

In Fig. 1 the vehicle frame is shown with a propeller shaft for a rear wheel drive. The arrangement of the cardan shaft on the vehicle frame is shown in more detail in FIG. 4.

Fig. 4 shows a vehicle frame according to the invention in a sectional side view so that the drive shaft, the cross member and the right frame side member of the vehicle frame are visible. The right front wheel is indicated on the left in FIG. 4. At a distance from this, the rear wall of the driver's cab 25 is shown schematically.

In the embodiment shown in FIGS. 1 and 4, the cardan shaft extends from the cab sub-module 1 to the rear axle module 3. Where the cardan shaft is connected at the front to the transmission, not shown, of an engine, not shown, the cardan shaft has a front constant velocity joint 12 on (Fig. 4). The constant velocity joint 12 is connected to a front universal joint shaft part 13, which ends in a rear constant velocity joint 14. The middle propshaft part 16 connects to the rear constant velocity joint 14.

The middle articulated shaft part 16 is rotatably mounted on the cross member 5 via an intermediate bearing 15. 4, this intermediate bearing 15 is arranged in the vicinity of the constant velocity joint 14. An advantage of this arrangement is the good vibration damping associated with it. The middle joint shaft part 16 ends in a joint 17. This joint 17 is shown in FIG. 4 as a constant velocity joint. In a preferred embodiment, however, the joint 17 is designed as a universal joint. This solution is less expensive than a constant velocity joint.

The rear joint shaft part 19 is arranged behind the joint 17. The rear articulated shaft part 19 is mounted on the cross member 7 in a manner which is favorable for vibrations near the articulation 17 by means of an intermediate bearing 18. The rear joint shaft part 19 ends in a joint 20. In FIG. 4 the joint 20 is shown as a constant velocity joint.

In a preferred embodiment, however, the joint 20 is inexpensively designed as a universal joint.

The rear joint 20 connects the propeller shaft to the differential 22. A suspension 21 for the differential 22 is located on the cross tube 9.

As shown in FIG. 4, the differential 22 is connected to the wheel carriers of the wishbones 24a, 24b via two wheel drive shafts (see also FIG. 1). For this purpose, a passage 31a, 31b for a wheel drive shaft is provided for each of the frame side members 8a and 8b. Where the passage 31a, 31b is provided for the wheel drive shaft, the frame side member 8a, 8b has a frame beam 29a, 29b. The frame beam 29a, 29b compensates for the weak point on the longitudinal frame member 8a, 8b which has arisen through the passage 31a, 31b.

In addition, the area near the passage 31a, 31b is stabilized by the cross members 10 and 32. The cross member 10 is aligned perpendicular to the road. The cross member 32, like the axle cross member 23, is parallel to the driving track aligned. In this case, the axle cross member 23 is arranged above the passage 31a, 31b and the cross member, in contrast, is offset to the rear at the bottom. This arrangement of the cross members 23 and 32 with respect to one another also results in a spatial stabilization of the frame side members 8a, 8b with respect to one another. This spatial stabilization is further enhanced by the alignment and arrangement of the cross member 10.

Claims

claims

1. Vehicle frame for a motor vehicle, designed as a lead frame with

- a cab substructure module (1), with a frame lowering (4a, 4b),

- a central module (2) with two longitudinal frame members (6a, 6b), the two longitudinal frame members (6a, 6b) of the central module (2) being connectable to the lowering frame (4a, 4b) of the cab substructure module (1), and

- A rear axle module (3), characterized in that the rear axle module (3) has a rear axle support structure designed as an assembly, with two frame side members (8a, 8b), a cross tube (9), on the left and right each of a trailing arm or semi-trailing arm (24a , 24b) is mounted, and an axle cross member (23).

2. Vehicle frame according to claim 1, characterized in that the rear axle support structure is designed as a preassembled assembly which can be used in the vehicle frame.

3. Vehicle frame according to one of claims 1 to 2, characterized in that the rear axle module (3) has stiffening struts (11) which connect the cross tube (9) to the frame side members (8a, 8b) and / or a further cross member (10) ,

4. Vehicle frame according to one of claims 1 to 3, characterized in that a further rear axle (30) is provided.

5. Vehicle frame according to one of claims 1 to 4, characterized in that a multi-part propeller shaft is provided for a rear-wheel drive.

6. Vehicle frame according to claim 5, characterized in that the multi-part drive shaft has a front drive shaft part (13) with two constant velocity joints (12, 14).

7. Vehicle frame according to claim 5 or 6, characterized in that the multi-part drive shaft has a rear drive shaft part (19) with two universal joints (17, 20).

8. Vehicle frame according to claim 5 or 6, characterized in that the multi-part drive shaft has a rear drive shaft part (19) with two constant velocity joints (17, 20). Vehicle frame according to claims 4 to 7, characterized in that the two frame longitudinal members (8a, 8b) of the rear axle module (3) each have a frame beam (29a, 29b) with a passage (31a, 31b) for a wheel drive shaft.