Area of technology

The present invention relates partly to a vehicle frame, in accordance with the preamble to patent claim 1, and partly to a method of assembling it, in accordance with the preamble to patent claim 5.

State of the art

A common practice in large vehicle frames, particularly for buses, is to begin by placing the longitudinal side members in their intended mutual position, followed by fitting the requisite number of cross-members to the side members in various ways. One of the usual ways is to insert the cross- members sideways into apertures in the side members, followed by welding or soldering around the apertures in order to achieve proper strength. This method has disadvantages, however, with regard to access for welding and also makes the surface treatment of the vehicle frame difficult. See, for example, CH 302351 and DE 801607.

Even if welding is not adopted and permanent bolting is used instead, the fact that the latter cannot be applied to the cross-members until they are in position causes problems.

Object of the invention

The object of the invention is to create a vehicle frame which is easy to assemble and which allows proper surface treatment of constituent parts before assembly. It is particularly desirable for environmental reasons to be able to powder coat constituent parts beforehand.

Brief description of the invention

A simplified and improved vehicle frame is achieved by the

features set out in the characterising part of patent claim 1, and simplified and improved assembly is made possible by the features indicated in the characterising part of patent claim 5.

Designing the vehicle frame so that before assembly the cross-members are provided with requisite fastening devices and so that the side members can be pushed into position on the cross-members with clearance makes it possible to join them together by means of threaded connections. This means that surface treatment already carried out will suffice and not be destroyed during assembly. A particular advantage from an environmental point of view is that the constituent parts of the frame can be powder coated before assembly. It also becomes possible to use simple and flexible assembly equipmen .

Further features and advantages of the invention are indicated in the description below.

List of drawings

Fig. 1 shows a perspective view of a vehicle frame according to the invention and

Fig. 2 shows a portion of a cross-member before the assembly of the vehicle frame.

Description of preferred embodiments

As may be seen in Fig. 1, a vehicle frame 1 according to the invention is composed of two elongated side members 2 and 3 and three shorter cross-members 4, 5 and 6. The side members 2 and 3 are at a certain mutual spacing and run in the longitudinal direction of the vehicle. The cross-members are arranged at right angles to the side members, through which they run and to which they are joined so that a rigid vehicle frame 1 is formed. To this end the side member 2 is provided

with apertures 2a, 2b and 2c and the side member 3 is correspondingly provided with apertures 3a, 3b and 3c. These apertures are large enough for it to be possible to run the cross-members through them with clearance. On each of the cross-members there are fastening devices 7, here in the form of flanges, for joining side members and cross-members together by means of fastening elements 8 (see Fig. 2) in the form of bolts and nuts.

The cross-members to be used in the vehicle frame are provided beforehand with fastening devices 7, advantageously by welding, which fastening devices are with advantage arranged in pairs according to Fig. 2 and situated along the cross-members in such a way as to achieve the intended spacing between the side members at the time of assembly.

The side members to be used in the vehicle frame 1 are provided beforehand with the requisite number of apertures for cross-members and with the requisite number of holes for fastening elements 8. In this respect it is desirable from the outset to design the side members so that the same side member design can be used for different frame variants. This means that, for example, there may be alternative apertures for cross-members and hence also alternative holes for the fastening elements 8, depending on what is necessary or desired.

The procedure of assembling the vehicle frame 1 according to the invention starts with fixing the requisite number of cross-members (provided with necessary fastening devices 7) at the intended mutual spacings d, e and in the intended positions relative to one another. This is followed by placing the side members 2 and 3 in position by moving them in the transverse directions marked by the arrows 9 and 10 so that they abut against the fastening devices 7 and reach their intended positions on the cross-members 4, 5 and 6. The next stage is to secure the fastening devices 7 and hence the cross-members to the side members by inserting bolts through

the holes provided for the purpose. During this assembly operation it is important that the cross-members are inserted through the apertures intended for them in the side members with clearance in order to avoid damage to the surface treatment, which is with advantage applied to the relevant parts before the assembly operation. This makes it possible, for example, for these parts to be powder coated and keep their paintwork intact during the assembly operation, not least because welding to the side members is obviated.

The vehicle frame 1 here depicted is intended, together with its long cross-members 2,3, to form part of a bus. Depending on the length of the bus, it may be desirable to connect two vehicle frames 1 of the type depicted by joining the side members together at suitable points in the vehicle. It is also possible to use two separate vehicle frames with a self- supporting vehicle body portion between them. The shape of the side members may of course be different from that here depicted. Depending on the design of the vehicle, they may for example be bent in various ways. Other types of sections may be used instead of channel sections.

The cross-members 4, 5 and 6 are depicted here with closed cross-sections, resulting in good rigidity, but other versions may also be desired. Assembling the vehicle frame 1 is facilitated if the portions of the cross-members 4, 5 and 6 which protrude beyond the side members 2, 3 are straight.

The type of fastening devices 7 and fastening elements 8 may also be varied as necessary or desired. Where applicable, certain cross-members may be provided with a larger or smaller number of fastening devices than other cross-members, depending on their location in the vehicle.

Further parts not here depicted are subsequently fitted in a conventional manner to the vehicle frame 1 here depicted.