FR3143695A1 - Joint for the elastic connection of two elements - Google Patents

Abstract

Articulation (10) for the elastic connection of two elements, which comprises an external ring (12) which extends axially around an axis (A) of articulation and which is delimited by an internal face (18) and a face external (20), said ring (12) being designed to be connected to a first element to be articulated, an internal core (14) mounted movable axially and radially along the axis (A) of articulation between at least one rest position and a working position, and an elastically deformable intermediate element (16) which connects the internal core (14) to the external ring (12), the articulation (10) being characterized in that the external ring (12) comprises at at least one adhesion zone (32) at the location of which the intermediate element (16) is radially integral with the internal face (18) of the external ring (12), and at least one freedom zone (34) at the location where the intermediate element (16) is radially separated from the external ring (12), said zone of freedom (34) being provided to limit the radial stiffness of the articulation (10). Figure for abstract: Figure 3

Description

Joint for the elastic connection of two elements

This patent application relates to the field of joints for the elastic connection of two elements.

The present invention will non-exclusively find advantageous applications in the automotive field, in particular by equipping a running gear device, for example to connect a suspension swing arm to the chassis of a motor vehicle.

The present invention is also suitable for equipping a support device for an engine of a motor vehicle, in order to filter the vibrations transmitted from the engine to the chassis.

It is known to interpose an elastic articulation between a first element and a second element of a mechanism, in particular to fulfill a function of damping and filtering vibrations between these two elements.

Typically, an elastic joint can be interposed between a suspension arm and a wheel support of a vehicle, or between an engine and the chassis of a vehicle.

An elastic joint comprising an outer ring, an inner core and an elastic spacer element is known from the state of the art.

The external ring extends axially around a hinge axis and is delimited by an internal face and an external face.

The outer ring is designed to be connected to a first element to be articulated, such as an engine block.

The internal core of the joint comprises a tubular body which extends axially along the joint axis inside the external ring and which delimits an axial passage hole intended to accommodate a second element to be articulated, such as a joint rod connected to the vehicle chassis.

This type of joint is designed to absorb axial forces along the joint axis, and radial forces perpendicular to the joint axis.

For this purpose, the internal core is mounted movable axially and radially along the articulation axis relative to the external ring, between at least one rest position in which the core is generally centered on the articulation axis, and a plurality of working positions.

Also, the spacer element is elastically deformable and it connects the internal core to the external ring allowing axial and radial mobility of the internal core.

The intermediate element is adapted to elastically return the internal core to its rest position.

Typically, the manufacture of the joint according to the prior art consists of gluing the peripheral external face of the core and the internal face of the ring, then overmolding the spacer element on the external ring and the internal core with a material of the type elastomer, so that the outer ring, the intermediate element and the inner core form an integral assembly.

The bonding connection between the intermediate element and the internal face of the outer ring makes it possible in particular to axially secure the inner core and the outer ring, so as to prevent any relative axial sliding of the core and the intermediate element.

This type of joint has a first characteristic of axial stiffness and a second characteristic of radial stiffness, characteristics whose value depends on the capacity of the intermediate element to oppose the axial forces and the radial forces transmitted between the core and the outer ring.

Stiffness can be defined as the characteristic of a joint expressing the ratio of the force it receives to the deformation obtained.

We speak of the stiffness ratio, or stiffness ratio, to determine the ratio between the axial stiffness and the radial stiffness of the joint.

This stiffness ratio is determined by the design of the joint, and it is generally between 0.1 and 0.3.

The present invention aims in particular to propose an elastic joint whose radial stiffness is limited in relation to the axial stiffness, so as to increase the stiffness ratio of the joint.

Thus, at equivalent axial stiffness with a joint according to the prior art, the joint according to the invention makes it possible to obtain a higher stiffness ratio.

• une bague externe qui s’étend axialement autour d’un axe d’articulation et qui est délimitée par une face interne et une face externe, ladite bague étant conçue pour être reliée sur un premier élément à articuler,
• un noyau interne comprenant un corps tubulaire qui s’étend axialement suivant l’axe d’articulation à l’intérieur de la bague externe et qui délimite un trou de passage axial destiné à accueillir un second élément à articuler, le noyau interne étant monté mobile axialement et radialement suivant l’axe d’articulation, par rapport à la bague externe, entre au moins une position de repos et une position de travail, et
• un élément intercalaire déformable élastiquement qui relie le noyau interne sur la bague externe en permettant la mobilité axiale et radiale du noyau interne, et qui est adapté pour rappeler élastiquement le noyau interne vers sa position de repos,

This objective, as well as others which will appear on reading the description which follows, is achieved with a joint for the elastic connection of two elements, which comprises:

• an external ring which extends axially around a hinge axis and which is delimited by an internal face and an external face, said ring being designed to be connected to a first element to be articulated,
• an internal core comprising a tubular body which extends axially along the articulation axis inside the external ring and which delimits an axial passage hole intended to accommodate a second element to be articulated, the internal core being mounted movable axially and radially along the hinge axis, relative to the outer ring, between at least one rest position and one working position, and
• an elastically deformable intermediate element which connects the internal core to the external ring by allowing axial and radial mobility of the internal core, and which is adapted to elastically return the internal core to its rest position,

the articulation being characterized in that the external ring comprises at least one adhesion zone at the location of which the intermediate element is radially integral with the internal face of the external ring, and at least one zone of freedom at the the location from which the intermediate element is radially separated from the external ring, said zone of freedom being provided to limit the radial stiffness of the joint.

Advantageously, the zone of freedom limits the elastic return force which is exerted on the external ring, by the elastic intermediate element, so as to limit the radial stiffness of the joint.

In addition, the joint according to the invention makes it possible to limit the radial stiffness, at equivalent axial stiffness, to increase the stiffness ratio of the joint.

According to other optional characteristics of the invention, taken alone or in combination:

- the adhesion zone is formed by a portion of the internal face of the external ring which is glued and which secures the intermediate element to the internal face of the external ring;

- according to a first embodiment, the freedom zone is formed by a window which radially passes through the outer ring. Thus, this zone of freedom delimited by the window does not adhere to the intermediate element;

- according to a second embodiment, the freedom zone is formed by an unglued portion of the internal face of the external ring;

- the spacer element is overmolded on the internal core and on the external ring;

- the external ring comprises a plurality of freedom zones which are angularly distributed regularly around the articulation axis;

- the core comprises at least one leg which extends radially from the body of the core, towards the outer ring, and which is designed to limit the radial movement of the core within the outer ring;

- the core comprises a plurality of radial legs which are distributed angularly in a regular manner around the articulation axis, in angular offset with said zones of freedom;

The invention also relates to a method of manufacturing a joint of the type described above, characterized in that it comprises at least one step of gluing at least a portion of the internal face of the external ring corresponding to said at least one adhesion zone, and a step of overmolding the intermediate element on the internal core and on the external ring.

According to another characteristic of the manufacturing process, the method comprises at least one masking step which is carried out before said gluing step and which consists of masking at least one portion of the internal face of the external ring corresponding to said at least one freedom zone.

Other characteristics and advantages of the invention will emerge on reading the description which follows, with reference to the appended figures, which illustrate:

an overall perspective view of an elastic joint according to the invention;

a perspective view of the ring and the core of the joint without the intermediate element, according to a first embodiment of the invention;

a front view in cross section along axis 3-3 of the , of the joint according to the first embodiment of the invention;

a side view in longitudinal section along axis 4-4 of the , of the joint according to the first embodiment of the invention;

a perspective view of the ring and the core of the joint without the intermediate element, according to a second embodiment of the invention.

In the description and the claims, we will adopt, on a non-limiting basis, the terminology longitudinal, vertical and transverse with reference to the trihedron L, V, T indicated in the figures.

Also, we will use, on a non-limiting basis, the expressions “radial” and “axial” in reference to the hinge axis A shown in the figures.

In all of these figures, identical or similar elements are identified by identical or similar reference signs.

We show in Figures 1 and 2 an elastic joint 10 which comprises an external ring 12, an internal core 14 and an intermediate element 16 which connects the core 14 to the external ring 12.

The main function of the articulation 10 is the filtration and absorption of vibrations and oscillations transmitted between a first element and a second element (not shown), such as for example between an engine and a chassis.

The outer ring 12, visible at the , has a generally cylindrical shape which extends axially around a longitudinal hinge axis A, and which is delimited radially by an internal face 18 and an external face 20.

The outer ring 12 is designed to be connected to a first element to be articulated (not shown), such as a housing of an engine block for example.

For this purpose, the joint 10 is designed to be housed in a housing of complementary shape formed by the first element to be articulated.

The internal core 14 of the joint 10 comprises a tubular body 22 which extends axially along the joint axis A within the external ring 12.

The body 22 of the core 14 delimits an axial hole 24 intended to accommodate a second element to be articulated, such as an articulation rod secured to a chassis of a motor vehicle for example.

Furthermore, as we can see in , the core 14 comprises four legs 26 which each extend radially from a peripheral face 28 of the body 22 of the core 14, towards the external ring 12, and which are distributed angularly in a regular manner around the articulation axis A.

The core 14 is mounted movable axially and radially along the hinge axis A, between a rest position illustrated in Figures 1 to 4, in which the core 14 is coaxial with the hinge axis A and centered axially with respect to to the outer ring 12, and a plurality of working positions in each of which the core 14 is substantially offset radially from the hinge axis A and/or offset axially relative to the outer ring 12.

For this purpose, the intermediate element 16 is elastically deformable, and it is made of elastomer material for example.

The intermediate element 16 allows the axial and radial mobility of the internal core 14, and it is adapted to elastically return the core 14 to its rest position.

With reference to Figures 3 and 4, it will be noted that the radial legs 26 which extend from the core 14 are provided to limit the radial travel of the core 14 up to an extreme position in which at least one of the legs 26 is in support radial against the internal face 18 of the external ring 12.

Furthermore, as we can see in , the intermediate element 16 delimits four slots 30 which pass axially through the intermediate element 16 and in each of which the free end of one of the legs 26 is arranged, to promote the radial movement of the core 14.

Also, it will be noted that the intermediate element 16 forms a crown 31 which envelops the external face 20 of the ring 12, so that the ring 12 is embedded in the intermediate element 16.

The crown 31 is intended to be interposed radially between the ring 12 and the housing of the first element to be articulated intended to accommodate the articulation 10.

According to the prior art, the internal face 18 of the ring 12 is glued with an adhesive to secure the ring 12 to the intermediate element 16.

According to an exemplary embodiment of the invention, several portions of the internal face 18 of the ring 12 are not glued to the intermediate element 16 to limit the radial stiffness of the joint 10.

Radial stiffness can be defined as the characteristic of a joint expressing the ratio of the radial force it receives to the deformation obtained.

More particularly, the internal face 18 of the ring 12 of the joint 10 according to the invention comprises an adhesion zone 32 and four freedom zones 34.

By “adhesion zone 32” is meant a zone at the location of which the intermediate element 16 is radially secured to the external ring 12, an adhesion zone 32 corresponding to a portion of the internal face 18 of the ring 12 which is integral with the intermediate element 16.

Conversely, the term “freedom zone 34” means a zone of freedom of movement at the location where the intermediate element 16 is radially separated from the outer ring 12.

According to a first embodiment of the invention illustrated in Figures 1 to 4, each freedom zone 34 is formed by a window which is provided on the external ring 12.

Each window has an overall oblong shape.

The freedom zones 34 are distributed angularly in a regular manner around the articulation axis A, that is to say that the freedom zones 34 are offset by an angle of 90 degrees.

The adhesion zone 32 covers the entire surface of the internal face 18 of the ring 12, with the exception of the freedom zones 34.

Preferably, the adhesion zone 32 of the base 12 is integrally linked to the intermediate element 16 by an adhesive (not shown), for example glue.

For this purpose, the articulation 10 according to the first embodiment of the invention is produced by a manufacturing process which comprises a first step of producing the external ring 12 and the windows forming the freedom zones 34, and a second step of gluing the internal face 18 of the ring 12 corresponding to the adhesion zone 32, that is to say the entire internal face 18 of the ring 12 with the exception of the voids formed by the windows of the freedom zones 34.

In addition, the method according to the invention comprises a third step of gluing the peripheral face 28 of the body 22 of the core 14.

Each gluing step consists, for example, of depositing a film of glue on the surfaces concerned.

Following the second and third gluing steps, the method according to the invention comprises a step of overmolding the intermediate element 16 on the internal core 14 and on the external ring 12.

The overmolding step consists of placing the ring 12 and the core 14 in a mold which delimits the shape of the intermediate element 16, then injecting a molding material into the mold.

Following the overmolding step, the process makes it possible to obtain a joint 10 according to the invention as described previously.

It will be noted that the four radial legs of the core 14 are distributed angularly in a regular manner around the articulation axis A in angular offset and alternating with the four zones of freedom 34.

According to a second embodiment of the invention illustrated in , each freedom zone 34 is formed by an unglued portion of the internal face 18 of the external ring 12, and not by a window.

According to this second embodiment, each zone of freedom 34 forms a strip which extends axially over the entire width of the ring 12 as illustrated by the broken lines on the , the freedom zones 34 being separated two by two by an adhesion zone 32, which are therefore also four in number.

Also, the freedom zones 34 are distributed angularly in a regular manner around the articulation axis A, that is to say following an angle of 90 degrees.

As with the first embodiment of the invention, each adhesion zone 32 is integrally linked to the intermediate element 16 by an adhesive (not shown), for example glue.

The joint 10 according to the second embodiment of the invention is produced by a manufacturing process which comprises a first step of producing the outer ring 12 and a second masking step which consists of masking the four portions of the internal face 18 of the ring 12 which correspond to the four freedom zones 34, by means of four masking elements (not shown).

Still according to the second embodiment of the invention, the method comprises a third step of gluing the internal face 18 of the ring 12.

Following the gluing step, the masking elements are removed to reveal the four zones of freedom 34 devoid of adhesive, so that the internal face 18 of the ring 12 has four zones of freedom 34 and four adhesion zones 32.

In addition, the method according to the second embodiment of the invention comprises a fourth step of gluing the peripheral face 28 of the body 22 of the core 14.

Each gluing step consists, for example, of depositing a film of glue on the surfaces concerned.

Following the third and fourth gluing steps, the method according to the second embodiment of the invention comprises a step of overmolding the intermediate element 16 on the internal core 14 and on the external ring 12.

Following the overmolding step, the process makes it possible to obtain a joint 10 according to the second embodiment of the invention as described previously.

Naturally, the invention is described in the above by way of example. It is understood that those skilled in the art are able to carry out different variants of the invention without departing from the scope of the invention.

For example, the different embodiments of the invention can be combined with each other.

Claims (6)

Articulation (10) for the elastic connection of two elements, which comprises:

• an external ring (12) which extends axially around a hinge axis (A) and which is delimited by an internal face (18) and an external face (20), said ring (12) being designed to be connected to a first element to be articulated,
• an internal core (14) comprising a tubular body (22) which extends axially along the hinge axis (A) inside the external ring (12) and which delimits an axial passage hole (24) intended to accommodate a second element to be articulated, the internal core (14) being mounted movable axially and radially along the axis (A) of articulation, relative to the external ring (12), between at least one rest position and a working position, and
• an elastically deformable intermediate element (16) which connects the internal core (14) to the external ring (12) allowing axial and radial mobility of the internal core (14), and which is adapted to elastically return the internal core (14) towards its rest position,

the articulation (10) being characterized in that the external ring (12) comprises at least one adhesion zone (32) at the location of which the intermediate element (16) is radially secured to the internal face (18). ) of the external ring (12), and a plurality of freedom zones (34) which are distributed angularly in a regular manner around the axis (A) of articulation at the location of which the intermediate element (16) is separated radially from the external ring (12), said zones of freedom (34) being provided to limit the radial stiffness of the articulation (10), and in that the core comprises a plurality of radial legs (26) provided to limit the radial displacement of the core (14) within the ring (12), which are distributed angularly in a regular manner around the axis (A) of articulation, in angular offset with said zones of freedom (34). Joint (10) according to claim 1, characterized in that the adhesion zone (32) is formed by a portion of the internal face (18) of the external ring (12) which is glued and which secures the intermediate element (16) on the internal face (18) of the ring (12). Joint (10) according to any one of the preceding claims, characterized in that the zone of freedom (34) is formed by a window which radially passes through the external ring (12). Joint (10) according to claim 2, characterized in that the freedom zone (34) is formed by an unglued portion of the internal face (18) of the external ring (12). Joint (10) according to any one of the preceding claims, characterized in that the intermediate element (16) is overmolded on the internal core (14) and on the external ring (12). Method of manufacturing a joint (10) according to any one of claims 1 to 5, characterized in that it comprises at least one step of gluing at least a portion of the internal face (18) of the external ring (12) corresponding to said at least one adhesion zone (32), and a step of overmolding the intermediate element (16) on the internal core (14) and on the external ring (12) and in this that it comprises at least one masking step which is carried out before said gluing step and which consists of masking at least one portion of the internal face (18) of the external ring (12) corresponding to said at least one zone of freedom (34).