Connection unit for mutually connecting two motor-vehicle suspension components

Abstract

Described here is a motor-vehicle suspension comprising two suspension components (1, 2) mutually pivotally connected by means of a connection unit (3), wherein one of said two components (1, 2) has a fork- shaped portion (1 ') comprising two parallel tines (4, 4'), and the other of said two components (1, 2) has an end portion (5) interposed between the two tines (4, 4') and connected to the tines (4, 4') through said connection unit (3). The connection unit (3) comprises a connection screw (8) inserted and fixed through a first hole (7) obtained on one of the two tines (4, 4'), said end portion (5), and a second hole (?') obtained on the other of said two tines (4, 4'). The connection unit (3) also comprises: - a bushing-shaped spacer member (9) engaged by interference within said second hole (7'), wherein said spacer member (9) comprises a through threaded hole (18) receiving said end portion (8"') of the screw connection (8), - wherein the outer surface of the bushing-shaped spacer member (9) and the surface of the second hole (7') comprise friction means (10) adapted to enable insertion of the spacer member (9) into the second hole (7'), and prevent rotation of said spacer member (9) around its own axis during fastening of the connection screw (8), without the aid of further elements.

Description

[0001] “Connection unit for mutually connecting two motor-vehicle suspension components” ****

[0002] TEXT OF THE DESCRIPTION

[0003] Field of the invention

[0004] The present invention refers to motor-vehicle wheel suspensions and in particular concerns a motor-vehicle suspension comprising two suspension components mutually pivotally connected by means of a connection unit, wherein one of said two components has a fork-shaped portion comprising two parallel tines, and the other of said two components has an end portion interposed between the two tines and connected to the tines through said connection unit, wherein said end portion interposed between the two tines comprises an element having a through hole oriented transversely with respect to the main axis of said tines, wherein said connection unit comprises a connection screw having a head portion inserted and fixed through a first hole obtained on one of the two tines, a central portion inserted and fixed within the through hole of the element, and an end portion inserted and fixed within a second hole obtained on the other of said two tines.

[0005] Prior art

[0006] According to the conventional technique, the connection unit further comprises a nut screw arranged in contact with one of the two tines on the opposite side with respect to the head portion of the fixing screw. Consequently, through the screw-nut screw coupling by means of an assembly tool and by applying the correct tightening torque, the two suspension components are mutually pivotally connected, in particular the fork-shaped portion is connected to the end portion of the other component.

[0007] This solution is particularly critical in the case of particularly massive fork-shaped portions for example made of aluminium, and more generally with materials and / or sections of the tines which have low elongation and high stiffness properties (for example magnesium or carbon). In fact, said fixing operations generate a pretension which acts on the suspension components to be connected, in particular on the fork. The fork-shaped portion therefore tends to deform due to the pretension and the tightening tension of the screw must overcome the opposition of the fork which tends to elastically return to its rest position.

[0008] Precisely in the case wherein the fork-shaped portion is made of aluminum (or other materials with low elongation and high rigidity), it may present states of residual tension which can affect the reliability of the component during the life cycle of the motor-vehicle. The need is therefore felt to propose an improving solution that can overcome said drawbacks.

[0009] In the Italian patent application N° 102022000017694, which forms part of the state of the art according to art. 46(3) CPI, the Applicant has proposed a connection unit to mutually connect two motor-vehicle suspension components of the type indicated at the beginning of this description. However, there is still a need to propose a further improved solution.

[0010] Object of the invention

[0011] The main object of the present invention is to overcome the drawbacks of known solutions.

[0012] In particular, an object of the present invention is to provide a motorvehicle suspension and a relative connection unit which is extremely reliable in withstanding the stresses to which the components are subjected in the life cycle of the motor-vehicle.

[0013] A further object of the present invention is to provide a connection unit which allows the tensions deriving from the assembly operations to connect the two suspension components to each other not to be effectively introduced.

[0014] A further object of the invention is to provide a solution with a structure that is relatively simple and economical to provide.

[0015] A further object is to provide a solution that is easily adaptable to be implemented with different motor-vehicle components to be connected, and on different classes of motor-vehicle, regardless of the materials applied and related stiffness and elongation properties.

[0016] A further object is to provide a solution that allows the tightening of the connection unit, limiting its size compared to the conventional solution, and consequently reducing the complexity of maneuvering the tools dedicated to closing the fastening.

[0017] A further object is to provide a connection unit that can be assembled in a simple and intuitive way, without interfering with other components or motor-vehicle parts that extend in a proximal position with respect to the connection unit.

[0018] Summary of the invention

[0019] These objects are achieved by means of a motor-vehicle suspension comprising two suspension components mutually pivotally connected by means of a connection unit, wherein one of said two components has a forkshaped portion comprising two parallel tines, and the other of said two components has an end portion interposed between the two tines and connected to the tines through said connection unit, wherein said end portion interposed between the two tines comprises an element having a through hole, wherein said connection unit comprises a connection screw having a head portion inserted and fixed through a first hole obtained on one of the two tines, a central portion inserted and fixed within the through hole of the element, and an end portion inserted and fixed within a second hole obtained on the other of said two tines, said motor-vehicle suspension being characterized in that:

[0020] - said connection unit comprises a bushing-shaped spacer member engaged by interference within said second hole, wherein said spacer member comprises a through threaded hole receiving said end portion of the connection screw,

[0021] - wherein the outer surface of the bushing-shaped spacer member and the surface of the second hole comprise friction means adapted to enable insertion of the spacer member into the second hole, and prevent rotation of said spacer member around its own axis during fastening of the connection screw, without the aid of further elements.

[0022] Further advantageous aspects of the invention are defined in the attached claims and in the following description.

[0023] Brief description of the figures

[0024] Further aspects and advantages of the invention will emerge from the following description with reference to the attached drawings, provided purely by way of non-limiting example, wherein:

[0025] - figure 1 illustrates a perspective view of two motor-vehicle suspension components mutually connected by a connection unit, according to an embodiment,

[0026] - figure 2 is an enlarged scale view of the connection area of the two suspension components illustrated in the previous figure,

[0027] - figure 3 is an exploded perspective view of some components of the previous figure,

[0028] - figure 4 is an enlarged scale cross-sectional view illustrating the connection area of the two suspension components and the connection unit, in an assembly phase preliminary to the final configuration, and

[0029] - figure 5 is a cross-sectional view showing the same components as the previous figure, in the final assembled configuration.

[0030] Detailed description of multiple embodiments

[0031] The following description illustrates various specific details aimed at an in-depth understanding of examples of one or more embodiments. The embodiments can be achieved without one or more of the specific details, or with other methods, components, materials, etc. In other cases, known structures, materials or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments. The reference to “an / one embodiment” in this description is to indicate that a particular configuration, structure or feature described in connection with the embodiment is comprised in at least one embodiment. Therefore, phrases such as “in an / one embodiment”, possibly present in different places in this description, do not necessarily refer to the same embodiment. Furthermore, particular conformations, structures or aspects can be combined appropriately in one or more embodiments and / or associated with the embodiments in a different way from as illustrated here, so for example an aspect exemplified here in relation to a figure it may be applied to one or more embodiments exemplified in a different figure.

[0032] The references illustrated here are for convenience only and therefore do not limit the extent of protection or the scope of the embodiment.

[0033] It should be noted that in the remainder of this description only the elements useful for understanding the invention are described, taking for granted - for example - that the wheel suspensions of a motor-vehicle, which comprise the components illustrated in the attached drawings, comprise all the elements per se known for functioning.

[0034] In the attached drawings, references 1 , 2 indicate two suspension components mutually pivotally connected by means of a connection unit 3.

[0035] According to the example illustrated in figure 1 , the two suspension components 1 , 2 are an oscillating arm pivotally connected to a wheel knuckle 2. The construction details relating to these components are not described as they are generally known to those skilled in the art. However, it should be noted that the present invention is equally applicable to other types of suspension components, such as oscillating rods and suspension frames.

[0036] For simplicity of explanation, in the following, the oscillating arm and the wheel knuckle are indicated respectively as first suspension component 1 and second suspension component 2.

[0037] With reference to figures 1 , 2, the first suspension component 1 comprises at least a fork-shaped end portion T comprising two spaced and parallel tines 4, 4’, which are connected to an end portion 5 of the second suspension component 2. This end portion 5 is interposed between the two tines 4, 4’ and connected to them by means of the connection unit 3, described in detail below.

[0038] The end portion 5 of the second suspension component 2 comprises an element 6 on which a through hole is made to be engaged by the connection unit 3. In one or more embodiments, the element 6 is a bushing of elastomeric material defining an articulation axis around which the second component 2 is pivotally mounted with respect to the two tines 4, 4’ of the fork-shaped portion T. In the illustrated embodiment, the articulation axis is substantially perpendicular to the main axes of the parallel tines 4, 4’.

[0039] The connection unit 3 comprises a connection screw 8 arranged to connect the fork-shaped portion T with the end portion 5 of the second suspension component 2. To this end, each tine 4, 4’ has a respective hole 7, 7’ respectively engaged with a head portion 8’ and an end portion 8”’ of the connection screw 8. With reference to the cross-sectional view of figure 5 which illustrates the final assembled configuration, the fixing screw 8 comprises a head portion 8’ inserted and fixed through a first hole 7 obtained on one of the two tines 4, 4’, a central portion 8” inserted and fixed within the through hole of the elastic element 6, and an end portion 8” inserted and fixed within a second hole 7’ obtained on the other of said two tines 4, 4’.

[0040] According to an essential aspect of the present invention, the connection unit 3 further comprises a spacer member 9 engaged by interference within said second hole 7’, intended to receive the end portion 8”’ of the connection screw 8. More particularly, the spacer member 9 is a bushing which has a through hole 18 for mutual engagement with the connection screw 8. The bushing comprises a cylindrical body engaged by interference within said second hole 7’.

[0041] Figure 4 is an enlarged scale cross-sectional view illustrating the connection area of the two suspension components 1 , 2 and the connection unit 3, in an assembly phase preliminary to the final assembled configuration. Note that only a part of the cylindrical body of the bushing is engaged within said second hole 7’ of the tine 4’, since during the fixing of the connection screw 8, the latter pulls the bushing which then slides axially within the hole 7’ until the final tightening determined by reaching the desired closing torque (figure 5).

[0042] The fork-shaped portion 1 ’ therefore tends not to deform due to the pre-tension resulting from the tightening of the components, and in particular of the tines 4,4’, which tend to elastically remain in the initial rest position. In this regard, one of the functions of the bushing-shaped spacer member 9 is precisely to preserve the fork-shaped portion T from states of residual tension which could affect the reliability of the component 1 during the life cycle of the motor-vehicle.

[0043] In one or more embodiments, the fork-shaped portion T is made of aluminium, while the bushing-shaped spacer member 9 is preferably made of steel. In other embodiments, the fork-shaped portion T is made of other materials with low elongation and high stiffness.

[0044] As indicated previously, during the fastening of the connection screw 8, the bushing-shaped spacer member 9 slides axially into the second hole 7’, preserving the first suspension component 1 with fork-shaped portion T from harmful residual tensions. According to a further aspect of the invention, the outer surface of the bushing-shaped spacer member 9 and the inner surface of the second hole 7’ comprise friction means 10 adapted to enable insertion of the spacer member 9 into the second hole 7’, and prevent rotation of the spacer member 9 around its own axis during the fastening of the connection screw 8, without the aid of further elements. In the illustrated embodiment, the friction means 10 are formed by a so-called ribbed (millerighe) coupling between the outer surface of the bushing-shaped spacer member 9 and the inner surface of the second hole 7’.

[0045] Looking in particular at figure 3, note that the outer surface of the spacer member 9 comprises a plurality of contiguous projections forming a first surface referred to as ribbed (millerighe) 11 , suitable for cooperating with a plurality of contiguous projections forming a second surface referred to as ribbed (millerighe) 12 formed along the surface of the second hole 7’. The projections of both surfaces 11 , 12 are in the form of rectilinear knurling extended along the axial direction. In the assembled configuration, the surfaces 11 , 12 are in mutual contact, with the projections of the first surface 11 interspersed with the projections of the second surface 12.

[0046] Without the aid of said friction means 10, by screwing the screw 8 into the bushing-shaped spacer member 9, the latter would rotate around its own axis, preventing the tightening of the components. The ribbed (millerighe) coupling between the spacer member 9 and the second hole 7’ of the tine 4’ therefore allows to avoid the use of a classic nut to fix the connection screw 8, and consequent reaction equipment (bushing- key / screwdriver) to “block” the rotation of the nut during tightening. During the fastening of the connection screw 8, it is precisely the interference between the ribbed (millerighe) surfaces 11 , 12 that prevents the rotation of the spacer member 9.

[0047] As an alternative to the ribbed (millerighe) knurling, on the surfaces 11 , 12 of the member 9 and of the second hole 7’ it is also possible to provide other types of grooved profiles, as long as they are functional to achieve the intended purposes.

[0048] In light of the previous description, a single component - defined by the bushing-shaped spacer member 9 with friction means 10 - allows to carry out multiple functions, without the aid of further pieces or equipment, in particular:

[0049] - anti-rotation of the bushing within its seat;

[0050] - carrying out the task of a classic nut screw;

[0051] - preventing the tines 4, 4’ from accumulating potentially harmful residual tension;

[0052] - significantly reducing the “packaging” necessary for the connection / tightening function.

[0053] Of course, notwithstanding the principle of the invention, the construction details and the embodiments may vary widely with respect to what has been described and illustrated purely by way of example, without thereby departing from the scope of the present invention.

Claims

CLAIMS1. Motor-vehicle suspension comprising two suspension components (1 , 2) mutually pivotally connected by means of a connection unit (3), wherein one of said two components (1 , 2) has a fork-shaped portion (T) comprising two parallel tines (4, 4’), and the other of said two components (1 , 2) has an end portion (5) interposed between the two tines (4, 4’) and connected to the tines (4, 4’) through said connection unit (3), wherein said end portion (5) interposed between the two tines (4, 4’) comprises an element (6) having a through hole, wherein said connection unit (3) comprises a connection screw (8) having a head portion (8’) inserted and fixed through a first hole (7) obtained on one of the two tines (4, 4’), a central portion (8”) inserted and fixed within the through hole of the element (6), and an end portion (8”’) inserted and fixed within a second hole (7’) obtained on the other of said two tines (4, 4’), said motor-vehicle suspension (1 ) being characterized in that:- said connection unit (3) comprises a bushing-shaped spacer member (9) engaged by interference within said second hole (7’), wherein said spacer member (9) comprises a through threaded hole (18) receiving said end portion (8”’) of the connection screw (8),- wherein the outer surface of the bushing-shaped spacer member (9) and the surface of the second hole (7’) comprise friction means (10) adapted to enable insertion of the spacer member (9) into the second hole (7’), and prevent rotation of said spacer member (9) around its own axis during fastening of the connection screw (8) without the aid of further elements.

2. Motor-vehicle suspension according to claim 1 , characterized in that said friction means (10) comprise a plurality of contiguous projections forming a first surface referred to as m illerighe (11 ) along the outer surface of the spacer member (9), adapted to cooperate with a plurality of contiguous projections forming a second surface referred to as m illerighe (12) along the inner surface of the second hole (7’).

3. Motor-vehicle suspension according to any of the previous claims, characterized in that said two suspension components (1 , 2) are a suspension oscillating arm and a wheel knuckle.

4. Motor-vehicle suspension according to any of the previous claims, characterized in that said fork-shaped portion (1 ’) is made of aluminium, and the bushing-shaped spacer member (9) is made of steel.

5. Motor-vehicle suspension according to any of the previous claims, characterized in that said element (6) is a bushing of elastomeric material defining an articulation axis.

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