SE540843C2

SE540843C2 - An arrangement for suspension of a vehicle cab

Info

Publication number: SE540843C2
Application number: SE1651246A
Authority: SE
Inventors: Hult Olle; Lundberg Ted; Larsson Mårten; Eriksson Rasmus
Original assignee: Scania Cv Ab
Priority date: 2016-09-21
Filing date: 2016-09-21
Publication date: 2018-11-27
Also published as: SE1651246A1; DE102017008553A1

Abstract

An arrangement for suspension of a truck cab (2) on a vehicle frame (3) comprises suspension elements connecting the truck cab to the frame while allowing cushioned relative movement of the cab with respect to the frame and at least one stiff elongated link (5) having opposite ends thereof connected to the frame (3) and the cab (2) so as to allow pivoting of the link with respect thereto. The arrangement comprises also a damper (10) having one end (11) thereof connected to one end (12) of the link (5) and another end (13) thereof pivotally connected to one of the frame (3) and the cab (2).

Description

An arrangement for suspension of a vehicle cab TECHNICAL FIELD OF THE INVENTION The present invention relates to an arrangement for suspension of a truck cab on a vehicle frame comprising • suspension elements configured to connect a said truck cab to a said frame while allowing cushioned relative movement of the cab with respect to the frame, and • at least one stiff elongated link configured to have opposite ends thereof connected to the frame and the cab so as to allow pivoting of the link with respect thereto, said link extending in a substantially vertical or vertical plane substantially in parallel with or in parallel with the longitudinal direction of the frame and the vehicle.

The invention is directed to all types of vehicles having a so-called truck cab for a driver of the vehicle and passengers suspended on the frame of the vehicle with the aim to isolate the truck cab and by that said driver and possible passengers from shock and vibrations of the vehicle frame or chassis.

Some trucks may in different driving situations face the problem that the suspension of the truck cab on the frame amplifies movements of the truck cab with respect to the frame so that the truck cab will carry out significant movements in the longitudinal direction of the vehicle or rotation about a vertical axis. Such movements may be generated by for instance road irregularities, variations of forces as a consequence of the rotation of the wheels, torque variations from a drive change of the vehicle, variations of forces caused by trailers and natural oscillations in the truck to mention some of possible sources to such movements, which may be experienced as unpleasant by the occupants of the cab and may also harm components of the truck.

BACKGROUND ART It has been tried to solve the problems mentioned above by selecting a suitable stiffness of bushings in said suspension elements, and when choosing stiff bushings the movements of the cab with respect to the frame in the longitudinal direction of the frame decreases but the vibration comfort does then get worse. When instead choosing weaker bushings the driver gets a feeling that the cab is no longer attached to the frame, which is unpleasant.

US 2002/0162697 A1 discloses an arrangement of a similar type as the one defined in the introduction provided with shock absorbers for damping vertical movements of the cab with respect to the frame. However, the arrangement disclosed in this document does not provide suitable damping in all types of driving situations of the vehicle.

SUMMARY OF THE INVENTION The object of the present invention is to provide an arrangement of the type defined in the introduction being improved in at least some aspect with respect to such arrangements already known.

This object is according to the invention obtained by providing such an arrangement with the features listed in the characterizing part of patent claim 1.

This new approach to connect one end of a damper to an end of a said link interconnecting the cab and the frame and extending in the longitudinal direction of the frame and the vehicle and pivotally connecting the other end of the damper to one of the frame and the cab advantageous vibration properties of the suspension of the truck cab on the frame with reduced movement in the longitudinal direction of the vehicle may be obtained. It is by this possible to have a comparatively low stiffness provided by the link connections to frame and cab in the longitudinal direction of the vehicle combined with a suitable damping through said damper by selecting the degree of stiffness of the connection to the first end of the link for solving the problems mentioned above. Furthermore, the damper will thanks to the connection thereof to said link follow the first end of the link in movements of the cab with respect to the frame resulting in small changes of the attack angle of the damper to the member (frame or cab) to which a first end of the link is connected.

According to an embodiment of the invention the first end of the damper is connected to said link through a bushing. The choice of stiffness of this bushing will then decide the magnitude of the damping action of the damper.

According to another embodiment of the invention said at least one link is configured to be arranged to connect to said truck cab in the region of the front thereof, which will result in a suitable position for a damper secured to that link.

According to another embodiment of the invention said at least one link is comprised by an anti-roll bar. The anti-roll bar may then be formed by two such links extending in parallel on different lateral sides of the cab and a torsional bar interconnecting the links. To combine a damper with such an anti-roll bar guiding the movement of the cab with respect to the frame results in an efficient damping of movements and vibrations of the vehicle cab.

According to another embodiment of the invention the arrangement comprises two said links configured to be arranged at different lateral sides of the truck cab, and a said damper is associated with each said link. Such an arrangement may advantageously reduce rotations of the cab about a vertical axis.

According to another embodiment of the invention said damper is a viscous damper. The use of such a damper and alternatively a damper in the form of a friction damper results in a possibility to efficiently reduce vibrations and large movements of the cab in the longitudinal direction of the vehicle with respect to the frame by combination thereof with said suspension elements and said at least one link.

According to another embodiment of the invention said opposite ends of said link have connections obtained by bushings with different stiffness, and said first end of the damper is secured to the link end provided with the bushing with lowest stiffness. The link end with the bushing with low stiffness will be most prone to move when exerted to load making an influence upon such movement by a damper most suitable at that location.

According to another embodiment of the invention said first end of the damper is secured to an end of the link connected to the cab. It is in such a case suitable to have the second end of the damper pivotally connected to the cab or to the frame.

According to another embodiment of the invention the first end of the damper is secured to an end of the link connected to the frame, and it is in this case preferred to have the second end of the damper pivotally connected to the frame or pivotally connected to the cab depending upon the actual appearance and design of the cab with respect to the vehicle and the mounting and design of said suspension elements.

The invention also relates to a vehicle having a truck cab moveably suspended on a frame of the vehicle according to the claim directed to such a vehicle.

Other advantages as well as advantageous features of the invention will appear from the description following below.

BRIEF DESCRIPTION OF THE DRAWINGS With reference to the appended drawings, below follows a specific description of embodiments of the invention cited as examples.

In the drawings: Fig 1 is a very schematic view of a vehicle schematically illustrating the suspension of a cab thereof on the frame or chassis of that vehicle, and Fig 2-5 are very schematic views illustrating the principle of arrangements for suspension of a truck cab on a vehicle frame according to four embodiments of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION Fig 1 shows schematically a vehicle 1 in the form of truck having a cab 2 for a driver and possible passengers suspended on a frame 3 or chassis of the vehicle. Suspension elements 4, such as different types of spring members, cushions and the like, are arranged between the cab 2 and the frame 3 for interconnecting these parts of the vehicle while allowing cushioned relative movement of the cab with respect to the frame. These suspension elements 4 are schematically indicated in the figure. The arrangement has also two stiff elongated links 5 on different lateral sides of the truck cab 2 connected with a torsional bar to each other. The links and the torsional bar are together an anti-roll bar. These links extend in a vertical plane in parallel with the longitudinal direction of the frame and the vehicle as shown by the arrow A. These links 5 forming the anti-roll bar are arranged to connect to the truck cab 2 in the region of the front 6 thereof and will guide the movements of the cab 2 with respect to the frame 3.

Fig 2 illustrates schematically an arrangement according to a first embodiment of the invention having a link 5 pivotally connected through bushings 7, 8 to the frame 3 and the cab 2. A damper 10 in the form of a viscous or friction damper has a first end 11 thereof connected by a bushing to the end 12 of the link 5 connecting to the cab and the other end 13 pivotally connected to the cab while extending in the same vertical plane as the link 5, i.e. in a vertical plane in parallel with a longitudinal direction of the frame and the vehicle. This means that the damper will change length while pivoting slightly around the axis 9 at the cab and then store energy in the bushing of that connection when the link 5 pivots around the axis 9 at the cab 2 and then provide the damping action to the corresponding movement of the cab.

Fig 3 illustrates an arrangement according to a second embodiment of the invention differing from that shown in fig 1 purely by that fact that the second end 13 of the damper 10 is pivotally connected to the frame 3 instead of the cab 2. Otherwise, the general function of this arrangements is the same as for the arrangement shown in fig 2.

Fig 4 shows an arrangement according to a third embodiment of the invention differing from the two previous ones by the fact that the damper 10 is here through the end 11 connected by a bushing to the end 14 opposite to the end 12 of the link 5 and has the end 13 pivotally connected to the frame 3.

Finally fig 5 illustrates schematically an arrangement according to a fourth embodiment of the invention differing from that shown in fig 4 only by having the end 13 of the damper 10 pivotally connected to the cab 2 instead of the frame 3.

The invention is of course in no way restricted to the embodiments described above, since many possibilities for modifications thereof are likely to be obvious to one skilled in the art without having to deviate from the scope of invention defined in the appended claims.

Although only one link and one damper has been shown in the schematic figures two or more such link-damper combinations may be arranged in parallel to interconnect the cab and frame of a vehicle to participate in suspending the cab on the vehicle frame.

Claims

1. An arrangement for suspension of a truck cab (2) on a vehicle frame (3) comprising • suspension elements (4) configured to connect a said truck cab to a said frame while allowing cushioned relative movement of the cab with respect to the frame, and • at least one stiff elongated link (5) configured to have opposite ends (12, 14) thereof connected to the frame and the cab so as to allow pivoting of the link with respect thereto, said link extending in a vertical plane in parallel with the longitudinal direction of the frame (3) and the vehicle (1), characterized in that the arrangement further comprises a damper (10) extending in a vertical plane in parallel with the longitudinal direction of the frame (3) and the vehicle (1) and configured to have a first end (11 ) thereof connected to a first end (12, 14) of said link (5) and a second end (13) thereof pivotally connected to one of said frame (3) and said cab (2).

2. An arrangement according to claim 1, characterized in that said first end (11) of the damper (10) is connected to said link (5) through a bushing.

3. An arrangement according to claim 1 or 2, characterized in that said at least one link (5) is configured to be arranged to connect to said truck cab (2) in the region of the front (6) thereof.

4. An arrangement according to any of the preceding claims, characterized in that said at least one link (5) is comprised by an anti-roll bar.

5. An arrangement according to any of the preceding claims, characterized in that it comprises two said links (5) configured to be arranged at different lateral sides of the truck cab (2), and that a said damper (10) is associated with each said link.

6. An arrangement according to any of the preceding claims, characterized in that said damper (10) is a viscous damper.

7. An arrangement according to any of claims 1-5, characterized in that said damper (10) is a friction damper.

8. An arrangement according to any of the preceding claims, characterized in that said opposite ends (12, 14) of said link (5) have connections obtained by bushings (7, 8) with different stiffness, and that said first end (11) of the damper (10) is connected to the link end provided with the bushing with lowest stiffness.

9. An arrangement according to any of the preceding claims, characterized in that said first end (11) of the damper (10) is connected to an end (12) of the link (5) connected to the cab

10. An arrangement according to claim 9, characterized in that the second end (13) of the damper (10) is pivotally connected to the cab (2).

11. . An arrangement according to claim 9, characterized in that the second end (13) of the damper (10) is pivotally connected to the frame (3).

12. An arrangement according to any of claims 1-8, characterized in that the first end (11 ) of the damper (10) is connected to an end (14) of the link (5) connected to the frame (3).

13. An arrangement according to claim 12, characterized in that said second end (13) of the damper (10) is pivotally connected to the frame (3).

14. An arrangement according to claim 13, characterized in that said second end (13) of the damper (10) is pivotally connected to the cab (2).

15. A vehicle having a truck cab (2) movably suspended on a frame (3) of the vehicle (1), characterized in that the vehicle is provided with an arrangement for suspension of the truck cab (2) on the vehicle frame (3) according to any of the preceding claims.