WO2019084649A1

WO2019084649A1 - Structural arrangement for a pneumatic suspension arm bushing

Info

Publication number: WO2019084649A1
Application number: PCT/BR2018/050400
Authority: WO
Inventors: Antonio Marcos MACIEL DA SILVA; Fabio Rossi
Original assignee: Randon S/A Implementos E Participações
Priority date: 2017-11-01
Filing date: 2018-10-31
Publication date: 2019-05-09
Also published as: BR202017023671U2; BR202017023671Y1; UY4705U

Abstract

The present utility model relates to a structural arrangement for a pneumatic suspension arm bushing, used preferably in trailer or semi-trailer suspensions, said bushing comprising a solid elastomer body (1) of cylindrical format and with uniform radial rigidity, having two faces (4, 5) in the free state prior to being mounted in the eyelet (3) of a suspension arm, forming convex truncated cones, terminating at the centre in a metallic tube (2) axially adhered to the elastomer.

Description

"BUILT-IN CONSTRUCTIVE ARRANGEMENT FOR PNEUMATIC SUSPENSION ARM"

The present utility model relates to a constructive arrangement introduced in a pneumatic suspension armature bush, preferably used in trailer and semi-trailer suspensions, said bushing comprising a cylindrical-shaped elastomer solid body and uniform radial stiffness, the two faces forming convex cone trunks, in the free state, before being mounted on the eye of a suspension arm, terminating in the center in a metal tube axially adhered to the elastomer.

ANTECEDENTS OF THE UTILITY MODEL

[002] Part of the freight vehicles currently traveling on the highways is equipped with a pneumatic suspension, in view of the favorable conditions of comfort and protection of the load offered by this type of suspension.

[003] In this sense, increasingly, new models and improvements in suspensions are developed, and their components improved to meet market demands.

Among the various models of pneumatic suspensions in use, we highlight those which are provided with two longitudinal arms rigidly attached to the vehicle axis, said arms having one of the ends labeled by pivoting bearings to supports attached to the chassis of the vehicle.

[005] The pivot bearings of the arms of a pneumatic suspension are subjected, in use, to forces in the vertical, horizontal, axial and torsional directions, due to the conditions offered by the load and the roll of the vehicle in the curves. It is desirable that such bushings be capable of absorbing and withstanding these forces, including the impacts and vibrations generated by the wheels, and on the other hand having an extended service life.

In pneumatic suspension models having two longitudinal arms rigidly attached to the vehicle axle body of the prior art, the bushes are generally used in the pivoting bearing of the type claimed in US Pat. No. 7252298, which bushing body is provided with regions with voids and with metallic plates adhered in the solid parts, providing a difference of radial stiffness in the vertical and horizontal directions, as shown in Figure 8.

In the state of the art there are also in use various other types of bushings for the described application, being constructed in a complex manner, with its body provided with regions with voids and other constructive forms that provide different stiffness between the vertical and horizontal directions, as shown in Figure 9.

Said bushing models, because they are provided with regions with voids, or are provided with metal plates, present some drawbacks, although, given the requirements of variable radial stiffness. Moreover, because they are subject to the stresses generated by the vehicle on the suspension pivot bearing, they exhibit a life of reduced durability, generating stops of operation of the vehicle for the maintenance and premature replacement of bushings, which generates costs with the substitution of this component, and also loss of operational revenue.

Patent US7252298 discloses a pivoting lever used in a vehicle suspension arm including a housing, a resilient bushing compressed and adhered to a rigid axial tube housing. The bushing has void spaces, above and below the axial tube when the pivotal member is mounted for use, and engaging members that extend between the void spaces on opposite sides of the axial tube. When the pivot bearing is being used in an arm suspension in a vehicle, the voids increase the flexibility of the riser with vertical load on the pivot bearing. The stiffness elements increase the stiffness of the bushing in a horizontal direction by improving the dynamics of the vehicle and reducing vibrations. Preferably, the stiffness members are of sheet steel adhered to the bushing, and extend arcuately around the axial tube. The voids extend partially through the axial thickness of the bushing on opposite sides and generally accurately over the tube. The bushing also has opposing circumferential portions. The end portions extend circumferentially beyond the diametrically opposite portions of the outer circumference of the tube and are in the vicinity of the tube. The edges of the reinforcing members extend to the opposing end portions of the cavities.

The object of the invention is to have a pivoting lever for rigid arm suspension including a resilient cylindrical bushing and a rigid axial tube fixed in the bushing, providing a differentiated radial stiffness between the vertical and horizontal directions.

The drawbacks encountered in the pivot bearing bushing of said abovementioned patent are the same as described above.

The initial proposition of the resilient bushing used in the vehicular suspension arm pivot bearing as described in US7252298 has resulted in the solution found to solve the aforementioned drawbacks by means of a new pneumatic suspension armature bushing, which comprises a body solid in cylindrical-shaped elastomer and uniform radial stiffness, the two faces forming convex conical trunks, ending at the center in a metal tube adhered to the elastomer.

It is therefore a necessity of the state of the art to develop new sleeve for pneumatic suspension arm, to increase durability and reduce maintenance costs, and further rendering the vehicle more operable.

OBJECTIVES OF THE UTILITY MODEL

The purpose of the present utility model is to provide a new, more durable uniform radial stiffness pneumatic suspension sleeve which supports the stresses in the suspension pivot bearing generated by loading and rolling of the vehicle in the bends, taking into account the severe operating conditions. Another object of the present utility model is to reduce maintenance costs of the vehicle.

Another object of the present utility model is to make the vehicle more operable.

DESCRIPTION OF THE FIGURES

Figure 1 - Axial cross-sectional view of the pneumatic suspension arm bushing, in the free state before being mounted to the housing eye, object of the present utility model;

Figure 2 - Flat view of the left face of the bushing of Figure 1;

Figure 3 - Plane axial view of the bushing of Figure 1, mounted on the eye of the suspension arm, object of the present utility model;

Figure 4 shows a plan view in axial section of a variation of the shape of the air suspension arm sleeve, in the free state before being mounted to the housing eye, object of the present utility model;

Figure 5 - Flat view of the left face of the bushing of Figure 4;

Figure 6 - Plane axial view of the bushing of Figure 4 mounted to the eye of the suspension arm, object of the present utility model;

Figure 7 - Exploded perspective view of the bushing with the arm of a pneumatic suspension;

Figure 8 - Perspective view of a bushing with variable radial stiffness provided with metal plates in the rubber body of the prior art; Figure 9 - Perspective view of a bushing with variable radial stiffness endowed only with voids of the rubber body of the prior art.

DESCRIPTION OF WIDTH OF THE UTILITY MODEL

According to the attached Figures, the present utility model relates to a PNEUMATIC SUSPENSED ARM BUS CONSTRUCTION ARRANGEMENT, preferably used in trailers and semi-trailers, said bushing comprising a solid body (1) in cylindrical-shaped elastomer adhered to an axially centralized metal tube (2), the bush being assembled under pressure in a housing of the eye (3) of a suspension arm.

As shown in Figure 1, the bushing of the present utility model has the solid body

(I), the faces (4,5) extending from the metal tube (2) to the cylindrical surface (6) forming convex conical trunks, the intersection of the faces (4, 5) with the surface (6) forms radii (7, 8), respectively.

In a shape variation, as shown in Figure 4, the cylindrical regions 6 which comprise the outer diameter of the bushing are separated by an annular depression region 11, smaller in diameter than the cylindrical regions 6, . This region in annular depression

(II) can start next to the tube (2), or vary in diameter depending on the desired radial stiffness.

The pneumatic suspension arm sleeve required in the present utility model is intended for an arm housing, the eye (3) of which has internal diameter close to 140 mm and width close to 163.5 mm. The outer diameter of the bushing body in the free state is greater than the internal diameter of the eye (3) in order to exert sufficient elastic pressure against the inner walls of the eye (3), so as to remain attached thereto until the end of your life in use. Likewise, the dimension of the cylindrical side 6 of the bushing in the free state must be smaller than the width of the eye 3, this dimension being defined as a function of the elastic deformation of the elastomer. Thus, when the bushing is inserted into the eyelet 3, the elastomer moves axially until it engages the eye 3 forming convex edges 9, 10 on the faces 4, 5 of the solid body 1 as shown Figures 3 and 6.

In order to meet the stiffness required for said application, a ratio between the inner diameter of the eye (3) and the outer diameter of the free bush (1) is defined over an extended service life, in addition to the hardness of the elastomer material , according to laboratory stiffness and durability tests. The dimension of the cylindrical side 6 of the free bushing is defined with assembly tests, after defining the outer diameter of the free bushing, which must completely fill the ends of the inner flat surface of the bushing (3) and result in the convex and bulged shape of the bushes. faces (4, 5) of the bushing body. Therefore, in order to have a satisfactory durability of the bushing, these conditions must be maintained because they are mandatory.

In the shape variations of the present utility model, shown in Figures 1, 4, the bush has solid body (1) and uniform radial stiffness, consisting of solid rubber compound with a hardness of about 75 Shore, with free outer diameter of approximately 153 mm, terminating with the faces (4, 5) forming convex trunks of oppositely facing faces, terminating against the centralized metal tube (2) having an outside diameter of approximately 60 mm, and with an approximate length of 171 mm. The inner diameter of the tube (2) is defined according to the axial fixing screw to the holder.

In other embodiments, pneumatic suspension armature bushings may be designed in other polymeric materials, and / or including embossed or shallow embossed details, without thereby decharacterizing the object required in the present utility model.

The tube (2) is adhered to the body (1) by vulcanization during the manufacturing process of the bushing, having the function of allowing axial attachment of the bushing to the suspension support by means of a special screw.

The bushing of the present utility model has the function of an articulation and damping element of the forces transmitted to the arm and the support of the suspension by the vehicle in transit on the roads, the improvements of said bushing having as objective the necessity to improve its durability in use, to meet the severe operating conditions.

In practice, the new bushing for pneumatic suspension arm offers greater durability for application under severe operating conditions, reducing maintenance costs, providing the vehicle with longer on-time operation, reducing maintenance costs . It will be readily understood by those skilled in the art that modifications may be made in the present utility model without thereby departing from the concepts set forth in the foregoing description. Such modifications should be considered as included within the scope of this utility model. Accordingly, the particular embodiments described in detail above are only illustrative and not limiting as to the scope of the present utility model, which should be given to the full extent of the appended claims and any equivalents thereof.

Claims

A constructional arrangement inserted in a sleeve for pneumatic suspension arm, characterized in that it consists of a solid elastomer body (1) adhered to an axially centralized metal tube (2), the solid body (1) comprising faces (4,5) (6), the intersection of the faces (4, 5) with the cylindrical surface (6) forming radii (7, 8) of the convex conical shape, extending from the metal tube (2) to the cylindrical surfaces , respectively.

A pneumatic suspension armature arrangement according to claim 1, characterized in that the cylindrical regions (6) are separated by a smaller diameter depression ring (11), which can start with the tube (2) , or vary in diameter.

A pneumatic suspension armature arrangement according to claim 1 or 2, characterized in that the faces (4, 5) have convex edges (9, 10), respectively, inside the eye (3) of the arm of suspension.