Iveco DAILY M.Y. 2012, Body Builder Instructions

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3-10
FITTING SUPERSCTRUCTURES D
AILY
Base - 02/2012 Printed 603.95.241
Connections between frame and counterframe
Connections between frame and counterframe
3.3 Connections between frame and counterframe
3.3.1 Choosing the type of body mounting
The selection of the type of connection to be used - if not provided initially by IVECO - is very important in terms of the subframe
providing strength and stiffness, for the appropriate body type.
It can be elastic (shelves or flanges) or rigid, resisting to shearing strains (longitudinal and transversal plates); choice must be based
on the function of the structure to be applied (see points 3.4 to 3.9), taking into account the stress transmitted from the additional
equipment to the vehicle chassis, both in static and dynamic conditions. Quantity, size and construction of the fastenings, properly
distributed along the length of the sub-frame, must be such as to ensure good connection between chassis and sub-frame.
The screws and flanges must have a resistance class no lower than 8.8, nuts must be provided with loosening prevention systems.
The first fastening must be fixed, if possible, approximately 250 to 350 mm from the front end of the sub-frame.
It is preferable to use the fastening elements already present on the vehicle chassis.
The aforementioned distance for the first fastening must be respected particularly when structures are fitted with loads concentrated
behind the cab (e.g. cranes, front tilting body cylinder, etc.), so that the stress on the chassis and the stability are improved. If necessary,
perform additional fastenings.
If a structure with characteristics differing from those for which the chassis body is approved needs to be installed (e.g. a tilting body
on a chassis approved for a fixed tray), suitable connections must be prepared (e.g. shelves must be replaced with shear-resistant
plates in the rear area of the chassis).
!
When anchoring the structure to the chassis, no weldings must be performed on the vehicle chassis
and its wings must not be pierced.
In order to improve the longitudinal or transverse securing of the connection, it is permissible to have holes on the flanges of the
side members, but only at the rear end of the members, over a length of not more than 150 mm, provided that the anchorage of
any cross members that may be present is not weakened (see Figure 3.12). The mountings shown in Figure 3.11 may be used, applying
the screws which connect the rear cross member or underrun brackets to the chassis.
Note: in all other cases, it is strictly prohibited to pierce the wings.
3.3.2 Body mounting characteristics
Elastic connections (see Figure 3.8, 3.9 and 3.10) allow limited movement between chassis and sub-frame; these connections
can be considered as cooperating in parallel with the two resisting sections, each taking care of a share of flexing moment
proportionally to its inertial moment.
With rigid connections (see Figure 3.11), the two profiles can be considered having a single resisting section, provided that the
quantity and distribution of connections are such as to support the consequent shearing forces.
The possibility of creating a single resisting section between chassis and sub-frame allows reaching greater resisting capacity compared
to connections with shelves or flanges, with the following benefits:
- lower height of the subframe profile under the same bending moment acting on the section;
- higher bending moment under the same subframe profile dimensions;
- further increase of resisting capacity if materials with high mechanical characteristics are used for the sub-frame.