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1. WO2020117055 - ENSEMBLE DE SUSPENSION POUR SUSPENDRE UNE UNITÉ DE POST-TRAITEMENT D'ÉCHAPPEMENT À UN CHÂSSIS D'UN VÉHICULE UTILITAIRE À MOTEUR

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]

Title: A suspension assembly for suspending an exhaust after treatment unit to a frame of a commercial motor vehicle

The invention relates to a suspension of an exhaust after treatment unit to a frame of a commercial motor vehicle, such as a truck or a tractor unit.

A commercial motor vehicle is commonly provided with an exhaust after treatment unit to reduce the environmental load of the exhaust gases produced by the internal combustion engine of the commercial motor vehicle. It is known that a suspension assembly for suspending such an exhaust after treatment unit to a frame of a commercial motor vehicle comprises a load force limiter to avoid large movements of the exhaust after treatment unit as a result of vibrations and to reduce the load forces transferred from the frame of the commercial motor vehicle to the exhaust after treatment unit during operation of the commercial motor vehicle to prevent damage to the exhaust after treatment unit. However, there is a constant desire to improve the reduction of transfer of load forces in particular due to torsional loads as a result of vehicle chassis deformation during driving of the commercial motor vehicle on irregular roads.

It is an object of the present invention to provide an alternative suspension assembly for suspending an exhaust after treatment unit to a frame of a commercial motor vehicle in which the transfer of load forces from the frame of a commercial vehicle to the exhaust after treatment unit is reduced. It is a further object of the present invention to provide a suspension assembly for suspending an exhaust after treatment unit to a frame of a commercial motor vehicle in which the transfer of load forces from the exhaust after treatment unit as a result of chassis or frame deformation of a commercial vehicle, in particular torsional deformation acting in two directions can be reduced.

According to the invention at least one of the objects is obtained by providing a suspension assembly for suspending an exhaust after treatment unit to a frame of a commercial motor vehicle, said suspension assembly comprising a suspension rod having a first part with a first end connected to a lower edge of the exhaust after treatment unit and a second part with a second end opposite the first end connected to a bracket of the frame, said suspension assembly further comprising a load force limiter arranged between the first end and the second end, said load force limiter comprising:

- a first piston having a first piston rod and a first piston flange, said first piston rod being connected to the first part of the suspension rod or forming the first part of the suspension rod;

- a second piston having a second piston rod and a second piston flange, said second piston rod being connected to the second part of the suspension rod or forming the second part of the suspension rod;

- a housing comprising a first end wall and a second end wall opposite the first end wall, the first end wall comprising a first opening for receiving the first piston rod, the second end wall comprising a second opening for receiving the second piston rod, the housing further comprising a circumferential wall extending between the first end wall and the second end wall, the housing surrounding the first and the second piston flange;

- a first packet of Belleville springs arranged between the first piston flange and the first end wall;

- a second packet of Belleville springs arranged between the second piston flange and the second end wall;

- a third packet of Belleville springs and a fourth packet of

Belleville springs arranged between the first piston flange and the second piston flange; and

- a washer arranged between the third packet of Belleville springs and the fourth packet of Belleville springs. By using such a load force limiter in a suspension assembly for suspending an exhaust after treatment unit to a frame of a commercial motor vehicle the transfer of load forces from the chassis or frame of the commercial motor vehicle to the exhaust after treatment unit as a result of chassis or frame deformation of a commercial vehicle, in particular torsional deformation acting in two directions can be reduced efficiently with a relatively compact construction. Depending on e.g. the weight of the after treatment unit, the construction of the commercial motor vehicle and the expected conditions of the road on which the commercial vehicle is used the load force limiter can be tuned by e.g. selecting the dimensions and material of the Belleville springs, the number of Belleville springs in each stack and the pretension of the

Belleville springs in the housing generated during assembly of the housing and the Belleville springs, in particular when closing the housing.

In an embodiment of the suspension assembly according to the invention a number of filhng rings is arranged between the second packet of Belleville springs and the second end wall. In a further embodiment of the suspension assembly according to the invention a number of filling rings is arranged between the first packet of Belleville springs and the first end wall. By constructing the housing such that the space between the first piston flange and the first end wall and the space between the second piston flange and the second end wall is large enough to receive both a number of Belleville springs and a number of filling rings, the number of Belleville springs can be adapted to the desired load force reduction without amending the housing but by adding a respective number of filling rings. Preferably the housing has a length of 95 mm in order to accommodate the piston flanges, the packets of Belleville springs, the washer and the number of filling rings necessary for sufficiently reducing the transfer of load forces from the frame or chassis of the commercial motor vehicle to the exhaust after treatment unit.

In a further embodiment of the suspension assembly according to the invention each of the Belleville springs is made of spring-steel and has an outer diameter of 40 mm and a thickness of 1 mm. Preferably each packet of Belleville springs comprises two Belleville springs. It has appeared that the transfer of load forces from the frame to the exhaust after treatment unit as a result of chassis or frame deformation of a commercial vehicle, in particular torsional deformation acting in two directions can be reduced efficiently in most cases when each packet of Belleville springs comprises two Belleville springs and/or when the Belleville springs are made of spring-steel and have an outer diameter of 40 mm and a thickness of 1 mm.

In a still further embodiment of the suspension assembly according to the invention in unloaded condition of the load force limiter each

Belleville spring of the first and third packet of Belleville springs tapers outwardly in the direction from the first end wall to the washer, and each Belleville spring of the second and fourth packet of Belleville springs taper outwardly in the direction from the second end wall to the washer. In this manner the transfer of load forces from the frame to the exhaust after treatment unit as a result of chassis or frame deformation of a commercial vehicle, in particular torsional deformation acting in two directions can be reduced efficiently since depending on the direction of the load forces acting upon the load force li iter either the Belleville springs of the first and third packet absorb the load forces or even can turn over, i.e. reverse their orientation, or the Belleville springs of the second and fourth packet absorb the load forces or even can turn over, i.e. reverse their orientation. Please note that due to their construction the Belleville springs assume their original condition after the load forces have stopped acting on the load force limiter. As a result of the inventive suspension assembly the push pull rod with load force limiter has a high stiffness at relative low load forces and a low stiffness above the turning point of the Belleville springs as a result of which the transfer of vibrations and load forces from the frame of the

commercial motor vehicle to the exhaust after treatment unit is strongly reduced.

In a still further embodiment of the suspension assembly according to the invention the first end of the first part of the suspension rod is arranged lower in the commercial motor vehicle than the second end of the second part of the suspension rod. In this manner the exhaust after treatment unit is suspended in the commercial motor vehicle by the suspension assembly such that large movements as a result of vibrations of the frame are substantially reduced.

The invention will be further explained with reference to the Figure, in which a non-limiting exemplary embodiment of according to the invention is shown:

Fig. 1 schematically shows an embodiment of a suspension assembly for suspending an exhaust after treatment unit to a frame of a commercial motor vehicle according to the invention in perspective; and

Fig. 2 schematically shows an embodiment of a load force limiter in the embodiment of the suspension assembly shown in Fig. 1.

In Fig. 1 an embodiment of a suspension assembly 1 for suspending an exhaust after treatment unit 2 to a frame 3 of a commercial motor vehicle according to the invention is schematically shown in perspective.

The suspension assembly 1 comprises a suspension rod 4 having a first part 5 with a first end 6 connected to a lower edge of the exhaust after treatment unit 3. A second part 7 of the suspension rod 4 has a second end 8 opposite the first end 6 connected to a bracket 9 of the frame or chassis 3 of the commercial motor vehicle. In the embodiment shown in Fig. 1 the first end 6 of the first part 5 of the suspension rod 4 is arranged at a lower position in the commercial motor vehicle than the second end 8 of the second part 7 of the suspension rod 4 which second is attached to the bracket 9.

The suspension assembly 1 further comprises a load force limiter 10 arranged between the first end 6 and the second end 8 of the suspension rod 4. The load force limiter 10 is shown in more detail in Fig. 2 and comprises a first piston 11 having a first piston rod 12 and a first piston flange 13. In the embodiment shown in Figs. 1 and 2 the first piston rod 12 is connected to the first part 5 of the suspension rod 4 by means of e.g. bolts and nuts (not shown) which bolts extend through the attachment openings 14. In another embodiment (not shown) the first piston rod 12 can form the first part of the suspension rod, i.e. the first piston rod is extended such that it can be attached to the lower edge of the exhaust after treatment unit. The load force limiter 10 further comprises a second piston 15 having a second piston rod 16 and a second piston flange 17. In the embodiment shown in Figs. 1 and 2 the second piston rod 16 is connected to the second part 7 of the suspension rod 4 by means of e.g. a bolt and a nut (not shown) which bolt extends through an attachment opening 18. In another embodiment (not shown) the second piston rod 16 can form the second part of the suspension rod, i.e. the second piston rod is extended such that it can be attached to the bracket 9 of the frame or chassis 3 of the commercial motor vehicle.

The load force limiter 10 comprises a housing 19 having a first end wall 20 and a second end wall 2 opposite the first end wall 20. The first end wall 20 has a first opening 22 for receiving the first piston rod 12. The second end wall 21 comprises a second opening 23 for receiving the second piston rod 16. The housing 19 further comprises a circumferential wall 24 extending between the first end wall 20 and the second end wall 21, such that the housing 19 surrounds the first piston flange 13 and the second piston flange 17.

Inside the housing 19 a first packet A of two Belleville springs 25 is arranged between the first piston flange 13 and the first end wall 20 and a second packet B of two Belleville springs 25 is arranged between the second piston flange 17 and the second end wall 21. Further a third packet C of two Belleville springs 25 and a fourth packet D of two Belleville springs is arranged between the first piston flange 13 and the second piston flange 17 and a washer 26, preferably of rigid material, is arranged between the third packet C of Belleville springs and the fourth packet D of Belleville springs.

Please note that the invention is not restricted to the embodiment shown in which each packet of Belleville springs comprises two Belleville springs, but that in dependence of e.g. the weight of the exhaust after treatment unit the number of Belleville springs can vary. Further, in the shown embodiment each of the Belleville springs 25 is made of spring-steel and has an outer diameter of 40 mm and a thickness of 1 mm, but these dimensions can vary in dependence of the load force reduction to be achieved.

The housing 19 is constructed such that the space between the first piston flange 13 and the first end wall 21 and the space between the second piston flange 27 and the second end wall 21 provides enough room to receive both a number of Belleville springs 25 and a number of filling rings 27 so that the number of Belleville springs 25 in each packet can be adapted to the desired load force reduction without amending the housing 19 but by adding a respective number of filling rings 27. In the embodiment shown in Figs. 1 and 2 the housing has a length of 95 mm in order to accommodate the piston flanges 13, 17, the packets A-D of Belleville springs, the washer 26 and the number of filling rings 27 necessary for sufficiently reducing the transfer of load forces from the frame or chassis 3 of the commercial motor vehicle to the exhaust after treatment unit 2.

In Fig. 2 the unloaded condition of the load force limiter 10 is shown and is indicated in Fig. 2 each Belleville spring of the first packet A and third packet C of Belleville springs tapers outwardly in the direction from the first end wall 20 to the washer 26 and each Belleville spring of the second packet B and the fourth D packet of Belleville springs taper outwardly in the direction from the second end wall 21 to the washer 26. In this manner the transfer of load forces from the frame 3 to the exhaust after treatment unit 2 as a result of chassis or frame deformation of a commercial vehicle, in particular torsional deformation acting in two directions can be reduced efficiently since depending on the direction of the load forces acting upon the load force li iter 10 either the Belleville springs of the first packet A and third packet C absorb the load forces or even can turn over, i.e.

reverse their orientation, or the Belleville springs of the second packet B and fourth packet D absorb the load forces or even can turn over, i.e. reverse their orientation. After the load forces stop acting on the load force limiter 10 the Belleville springs of each packet assume their original condition due to their construction.