Rocker arm fixation system

Abstract

To provide a fixation system for adjustably fixing a rocker arm of a suspension to a chassis of a vehicle.SOLUTION: A rocker arm fixation system (10) for a vehicle suspension comprises: a second cam (16) rotating integrally with a rod through a shape adaptation coupling; a first nut (18) screwed into a first thread (30) to lock the position of a first cam (14); and a second nut (20) screwed into a second thread (32) to lock the position of a second cam (16). The second nut (20) has: a circumferential groove; a positioning hole that penetrates the circumferential groove; and an elastic clip in the form of an open ring adapted to be stored in a groove to hold a pin in the positioning hole.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fastening system for adjustably fastening a suspension rocker arm to a vehicle chassis. [Background technology]

[0002] Typically, a screw / cam assembly is used to secure a suspension rocker arm to a vehicle's mechanical chassis to adjust the suspension's toe-in and camber angles. Adjustments can be made transversely to the vehicle's direction of travel by rotating a screw and utilizing the thrust of a cam located on the shoulder of the mechanical chassis seat. In conventional vehicles powered by an internal combustion engine, this attachment requires inserting the screw from the front to the rear of the vehicle. Assembly is then completed by inserting a second cam mated to a properly positioned groove on the screw's shank and a hex nut that locks the cam's position on the screw. In the context of all-electric vehicles, the space for the rear attachment of the suspension rocker arm to the mechanical chassis is typically reduced due to the larger footprint of the electric powertrain, which precludes the use of conventional screw / cam assemblies similar to those used in internal combustion engine-powered vehicles. Generally, in practice, all locking systems for screws or threaded-shank nuts require the insertion of a cotter pin, circlip, spring clip, or equivalent component, requiring sufficient space for their proper placement, assembly, and fastening. Therefore, there is a need to provide a fastening system that is small in size, easy to use, and does not require tools for either the fasteners or the lock.

[0003] The object of the present invention is to provide a fastening system for adjustably fastening a suspension rocker arm to a vehicle chassis that does not have the drawbacks of the prior art and that can be easily installed and locked even when there is not a large working space. Summary of the Invention

[0004] This and other objects are fully achieved according to the present invention by the fastening system defined in the attached independent claim 1.

[0005] Advantageous embodiments of the fixing system according to the invention are set forth in the dependent claims, the content of which is to be understood as an integral part of the following description.

[0006] In summary, the present invention is based on the idea of ​​providing a fastening system for fastening a suspension rocker arm to a vehicle chassis in an adjustable manner, the fastening system comprising: a threaded rod extending along its length between a first end and a second end opposite the first end, the rod having a first thread at the first end and a second thread at the second end, the rod also having a locking cavity at the second end; a first cam arranged to rotate unitarily with the rod by form-fitting coupling with the rod at the first end; a second cam arranged to rotate unitarily with the rod by form-fit coupling with the rod at the second end; a first nut threaded onto the first thread of the rod to longitudinally lock the position of the first cam; a second nut threaded onto the second thread of the rod to lock the position of the second cam in the longitudinal direction, the second nut having a locking portion including a circumferential groove and a positioning hole formed through the groove; the fastening system further comprises a pin and a resilient clip in the form of an open ring, the resilient clip being received in the groove of the second nut to hold the pin in the locating hole; at a predetermined longitudinal threaded position of the second nut onto the second thread of the rod, the pin engages the locking cavity of the rod to longitudinally lock the position of the second nut on the rod; Fastening system.

[0007] This configuration of the fixing system, in particular the pin and the elastic clip associated with the second nut, allows for adjustment of the toe-in and camber angles as well as pre-fastening and locking, making it possible to adjust the suspension in a simple, fast and economical way, even when operating space is limited, such as in fully electric vehicles.

[0008] Preferably, said locking cavities are made in the form of holes extending laterally essentially perpendicular to said longitudinal direction, or in the form of circumferential grooves.

[0009] Advantageously, the pin is kept inserted in the locating hole and the locking cavity by the elastic clip, i.e. by the spring back force that the elastic clip exerts on the pin.

[0010] Preferably, the rod has the first groove at the first end that mates with the first cam by form-fitting, and the second groove at the second end that mates with the second cam by form-fitting.

[0011] Preferably, the second nut has an internal cavity with a respective internal thread adapted to threadably engage with the second thread of the rod, and the positioning holes of the second nut extend from an outer surface of the nut to the internal cavity.

[0012] In a preferred embodiment of the present invention, the pin and the elastic clip are made integrally. However, in a further preferred embodiment of the present invention, the pin has a pin groove, the elastic clip has a clip hole, and the pin is made integrally with the elastic clip by connecting the clip hole to the pin groove.

[0013] Advantageously, the portion of the rod included between the locking cavity and the second end of the rod has a frustoconical shape tapering in the direction from the locking cavity to the second end, and even more advantageously, in such a case, the elastic stiffness of the elastic clip is a function of the taper angle of the portion of the rod included between the locking cavity and the second end of the rod.

[0014] Finally, preferably, said second nut has a gripping portion adapted to allow adjustment of the screwing of said second nut onto the rod by means of a screwing tool.

[0015] Further characteristics and advantages of the invention will become apparent from the following detailed description, given purely by way of non-limiting example with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0016] [Figure 1] 1 is an axonometric view of a fastening system according to an embodiment of the present invention in relation to a vehicle chassis, with certain components omitted for clarity; FIG. [Figure 2] FIG. 2 is an exploded view of the fixation system of FIG. 1. [Figure 3] FIG. 2 is an exploded detail view of a portion of the fastening system of FIG. 1. [Figure 4a] Detail view of a part of the fastening system at five successive moments of screwing the second nut onto the second thread of the rod. [Figure 4b] Detail view of a part of the fastening system at five successive moments of screwing the second nut onto the second thread of the rod. [Figure 4c] Detail view of a part of the fastening system at five successive moments of screwing the second nut onto the second thread of the rod. [Figure 4d] Detail view of a part of the fastening system at five successive moments of screwing the second nut onto the second thread of the rod. [Figure 4e]Detail view of a part of the fastening system at five successive moments of screwing the second nut onto the second thread of the rod. DETAILED DESCRIPTION OF THE INVENTION

[0017] Referring to the drawings, a fixation system according to the present invention is generally designated 10 .

[0018] The fastening system 10 is particularly suitable for fastening a suspension rocker arm to a vehicle chassis T in an adjustable manner, but can also be used in different situations where space for adjusting the screw fastening is limited.

[0019] The fastening system 10 essentially comprises a threaded rod 12 , a first cam 14 , a second cam 16 , a first nut 18 , a second nut 20 , a pin 22 , and a resilient clip 24 .

[0020] The rod 12 extends along an extension or longitudinal direction x between a first end 26 and a second end 28 opposite the first end 26. A first thread 30 at the first end 26 and a second thread 32 at the second end 28 are made on the outer surface of the rod 12. For example, in an exemplary and essentially non-limiting manner, the first thread 30 extends in the longitudinal direction x between one-tenth and four-tenths of the total length of the rod 12, and the second thread 32 extends in the longitudinal direction x between six-tenths and nine-tenths of the total length of the rod 12. The rod 12 has a further locking cavity 34 located at or near the second end 28. For example, in an exemplary and essentially non-limiting manner, the locking cavity 34 is located a few millimeters from the second end 28. The locking cavity 34 may be provided as a through hole or blind hole (not necessarily circular in cross section) extending in a transverse direction y, essentially perpendicular to the longitudinal direction x, as can be seen in Figures 4a to 4e. Alternatively, the locking cavity 34 may be made in the form of a circumferential groove. In a manner that is clear per se, the locking cavity 34 may be made in any other equivalent shape. In a particularly advantageous embodiment of the invention, the portion of the rod 12a contained between the locking cavity 34 and the second end 28 of the rod 12 has a frustoconical shape. In particular, this portion of the rod 12a tapers outward in the longitudinal direction, or the diameter of its cross section in the transverse direction y decreases linearly from the locking cavity 34 to the second end 28 of the rod.

[0021] As previously mentioned, the fastening system 10 comprises a first cam 14 and a second cam 16. The first cam 14 and the second cam 16 are arranged to rotate together with the rod 12 by form-fitting couplings located at the first end 26 and the second end 28 of the rod 12, respectively, so that a rotation of the rod 12 corresponds to a similar rotation of the first cam 14 and the second cam 16. In a manner known per se, the angular positions of the first cam 14 and the second cam 16 are related to the toe-in and camber angles of the suspension, such that said angles can be changed and adjusted on command by rotating the rod 12. In a particularly preferred embodiment, the rod 12 has a first groove 36 at the first end 26 for form-fitting coupling with the first cam 14 and a second groove 38 at the second end 28 for form-fitting coupling with the second cam 16.

[0022] A first nut 18 is screwed, in a manner known per se, onto a first thread 30 externally relative to the first cam 14 to lock its movement along the longitudinal direction x.

[0023] Similarly, the second nut 20 is threaded onto the second thread 32 externally relative to the second cam 16 so as to prevent its movement along the longitudinal direction x. To this end, the second nut 20 has an internal thread 42 adapted to be threaded onto the second thread 32 of the rod 12.

[0024] The second nut 20 has a locking portion 40 and a gripping portion 44, the gripping portion being adapted to facilitate adjustment of the second nut 20 onto the second thread 32 of the rod 12 with a conventional screwing tool, thereby facilitating a grip of the second nut 20. The locking portion 40, in turn, includes a groove 46 and a locating hole 48. The groove 46 is formed on the outside and extends circumferentially. The locating hole 48 is formed through the groove 46. Preferably, as shown in the figures, the second nut 20 has an internal cavity 50 along which the internal thread 42 is formed, and the locating hole 48 extends from the outer surface of the second nut 20 to the internal cavity 50.

[0025] As mentioned above, the fastening system 10 further includes a pin 22 and a resilient clip 24 to enable a rigid connection between the rod 12 and the second nut 20. According to one embodiment of the present invention, the pin 22 and the resilient clip 24 can be made as a single piece or integrally. According to another embodiment of the present invention (shown), the pin 22 and the resilient clip 24 are made separately but connected to each other so that they move together. For example, the pin 22 has a circumferential pin groove 22a, the resilient clip 24 has a clip hole 24a, and the pin 22 is held together with the resilient clip 24 by connecting the pin groove 22a to the clip hole 24a. However, essentially, the resilient clip 24 constitutes a retaining element that serves to keep the pin 22 integral with the second nut 20 and resiliently bias the pin 22 toward the inside of the second nut 20.

[0026] According to the present invention, the elastic clip 24 is configured in the form of an open ring and is adapted to be received in the groove 46 of the second nut 20 in order to exert a springback force sufficient to keep the pin 22 integral with the second nut 20 and position it in the positioning hole 46. With this configuration, when the second nut 20 is screwed onto the second thread 32 of the rod 12, a predetermined longitudinal screw-in position is reached in which the pin 22 fits into the locking cavity 34 of the rod 12. In this way, the position of the second nut 20 on the rod 12 in the longitudinal direction x is locked.

[0027] As previously mentioned, rod portion 12a preferably tapers in a frustoconical manner towards second end 28. In such a case, the resilient stiffness of resilient clip 24 is advantageously selected as a function of the value of the taper angle of rod portion 12a included between locking cavity 34 and second end 28 of rod 12.

[0028] In particular, the screwing procedure can be seen in the sequence of Figures 4a through 4e. As the operator begins to screw the second nut 20 onto the second thread 32 of the rod 12, the pin 22 is positioned as shown in Figure 4a or does not contact the rod 12. As screwing continues, the position of the second nut 20 in the longitudinal direction x changes, and the pin 22 contacts the rod 12, particularly the portion of the rod 12a that has a frustoconical shape tapered toward the second end 28. As a result, as shown in Figures 4b and 4c, the pin 22 moves axially and partially emerges from the positioning hole 48 while remaining within said hole. As screwing continues, the position of the second nut 20 in the longitudinal direction x changes, and the pin 22 reaches the locking cavity 34 (Figures 4d and 4e). At this point, the spring back force applied to pin 22 by spring clip 24 forces said pin into locking cavity 34, thereby locking the position of second nut 20 on rod 12 in longitudinal direction x.

[0029] As is clear from the foregoing description, the present invention is readily applicable to vehicles comprising a chassis T and rocker arms adapted to connect a suspension to the vehicle chassis T. In such applications, it is sufficient to install the fastening system 10 according to the present invention such that the first cam 14 and the second cam 16 are arranged such that the position of the rocker arms is adjustable depending on the angular positions of the first cam 14 and the second cam 16. At this point, it is only necessary to adjust the angular position of the rod 12, thereby adjusting the first cam 14 and the second cam 16 and thereby adjusting the toe-in angle and camber angle of the vehicle suspension.

[0030] As is readily apparent from the above description, the fixing system according to the present invention makes it possible to achieve the objects of the present invention.

[0031] In particular, thanks to the user-friendly configuration of the fastening system, the angular position of the rod can be adjusted and locked in place even when the working space is very small, as is the case in at least partially electric vehicles.

[0032] Of course, without prejudice to the principles of the invention, the details of the embodiments and constructions may vary widely with respect to those described and illustrated purely by way of non-limiting example, without thereby departing from the scope of the invention as defined in the appended claims.

Claims

1. A fastening system (10) for fastening in an adjustable manner a rocker arm of a suspension to a chassis (A) of a vehicle, said fastening system (10) comprising: a threaded rod (12) extending along a longitudinal direction (x) between a first end (26) and a second end (28) opposite said first end (26), said rod (12) having a first thread (30) at said first end (26) and a second thread (32) at said second end (28), and further having a locking cavity (34) at said second end (28); a first cam (14) arranged to rotate unitarily with said rod (12) by a form-fitting coupling with said rod (12) at said first end (26); a second cam (16) arranged to rotate unitarily with said rod (12) by a form-fitting coupling with said rod (12) at said second end (28); a first nut (18) threaded onto the first thread (30) of the rod (12) to lock the position of the first cam (14) along the longitudinal direction (x); a second nut (20) screwed onto the second thread (32) of the rod (12) to lock the position of the second cam (16) along the longitudinal direction (x), the second nut (20) having a locking portion (40) including a circumferential groove (46) and a positioning hole (48) passing through the groove (46); The fastening system (10) further comprises a pin (22) and a resilient clip (24), the resilient clip (24) being formed as an open ring and adapted to be received in the groove (46) of the second nut (20) to retain the pin (22) in the locating hole (48); a pin (22) enters said locking cavity (34) of the rod (12) so as to lock the position of said second nut (20) on the rod (12) along the longitudinal direction (x) at a predetermined threaded position of said second nut (20) on the second thread (32) of the rod (12); Fastening system.

2. the locking cavity (34) is formed as a hole extending in a transverse direction (y) essentially perpendicular to the longitudinal direction (x) or as a circumferential groove; The fastening system of claim 1 .

3. a pin (22) is held in said locating hole (48) and said locking cavity (34) by a spring back force generated by an elastic clip (24); A fastening system according to claim 1 or 2.

4. the rod (12) having a first notch (36) at the first end (26) for form-fitting engagement with the first cam (14) and a second notch (38) at the second end (28) for form-fitting engagement with the second cam (16); The fastening system of claim 1 .

5. said second nut (20) having an internal cavity (50) with a respective internal thread (42) adapted to be screwed with the second thread (32) of the rod (12); The positioning hole (48) of the second nut (20) extends from an outer surface of the second nut (20) to an internal cavity (50) of the second nut (20); The fastening system of claim 1 .

6. The pin (22) and the elastic clip (24) are made as one piece. The fastening system of claim 1 .

7. The pin (22) has a pin groove (22a), and the elastic clip (24) has a clip hole (24a), The pin (22) is integral with the elastic clip (24) by interlocking engagement between the clip hole (24a) and the pin groove (22a). The fastening system of claim 1 .

8. a rod portion (12a) included between the locking cavity (34) and the second end (28) of the rod (12) has a frustoconical shape tapering from the locking cavity (34) towards the second end (28); The fastening system of claim 1 .

9. the elastic stiffness of the elastic clip (24) is a function of the taper angle of the rod portion (12a) included between the locking cavity (34) and the second end (28) of the rod (12); The fastening system according to claim 8.

10. the second nut (20) has a gripping portion (44) adapted to allow adjustment of the threading of the second nut (20) onto the rod (12) by a threading tool; The fastening system of claim 1 .

11. A vehicle suspension system comprising: a chassis (T); a rocker arm adapted to connect a suspension to the chassis (T) of a vehicle; and a fastening system (10) according to claim 1, the first cam (14) and the second cam (16) are arranged such that the position of the rocker arm is adjustable as a function of the angular positions of the first cam (14) and the second cam (16); vehicle.

Images