Rear suspension, in particular for a commercial vehicle provided with a load compartment, including torsion bars and related actuating members

Abstract

Rear suspension for a vehicle, in particular for a commercial vehicle provided with a load compartment for transporting goods to be delivered, wherein said rear suspension comprises a pair of longitudinal suspension arms (4) each having a main longitudinal body extending externally with respect to a rear portion of a respective side rail (2). The rear suspension further comprises two elastic devices configured as torsion bars (8) and two independent actuating members (10) respectively configured to rotationally drive a torsion bar (8) and consequently rotate the longitudinal arms (2) to vary the height of the load compartment.

Description

[0001] Rear suspension, in particular for a commercial vehicle provided with a load compartment, including torsion bars and related actuating members

[0002] TEXT OF THE DESCRIPTION

[0003] Field of the invention

[0004] The present invention relates to a rear suspension for a vehicle, in particular for a commercial vehicle provided with a load compartment, wherein the rear suspension comprises a pair of longitudinal arms.

[0005] Prior art

[0006] In the field of commercial vehicles provided with a load compartment for transporting goods to be delivered, manufacturers must design the vehicle structure considering the required dimensions and installation spaces for the rear suspension system, for example for the arrangement of traditional coil springs. For this purpose, the side rails are commonly made to form a substantially straight main central portion at a constant height from the ground, and a rear terminal portion that is substantially more raised. Consequently, the load floor comprises a rear portion that must be slightly raised compared to a main central portion, precisely in accordance with the aforementioned configuration of the side rails. However, these solutions are not fully satisfactory as it is desirable for the load surface to be as regular and at a constant height as possible along the entire extension of the compartment, thus ensuring easier loading and unloading operations for operators.

[0007] Object and summary of the invention

[0008] The object of the present invention is to propose a rear suspension for a vehicle, in particular for a commercial vehicle provided with a load compartment, that can meet the aforementioned needs.

[0009] A further object of the invention is to implement a rear suspension that is overall simple and low-cost.

[0010] According to the embodiments described below, these objects are achieved thanks to a rear suspension for a vehicle having the features recalled in the following claims.

[0011] The claims form an integral part of the teachings provided here in relation to the embodiments of the solutions described herein.

[0012] Brief description of the annexed figures

[0013] One or more embodiments will now be described, by way of non-limiting example only, with reference to the annexed drawings, wherein:

[0014] - Figure 1 is a perspective view of a rear suspension for a vehicle, according to possible embodiments,

[0015] - Figure 2 is a side view of the suspension of the previous figure,

[0016] - Figure 3 is an enlarged-scale perspective view of the suspension of the previous figures, highlighting a torsion bar and a related actuating member, according to possible embodiments,

[0017] - Figures 4,5 are exploded perspective views of some components of Figure 3, and

[0018] - Figure 6 is a further sectional view showing the components of Figures 3-5. Detailed description

[0019] In the following description, various specific details are illustrated for the purpose of providing a thorough understanding of various examples of embodiments according to the description.

[0020] The embodiments may be obtained without one or more of the specific details, or with other processes, components, materials, etc.

[0021] In other cases, known structures, materials, or operations are not illustrated or described in detail so that various aspects of the embodiments are not obscured.

[0022] A reference to "an embodiment" or "a solution" within the context of the present description is intended to indicate that a particular configuration, structure, or feature described in relation to the embodiment is included in at least one embodiment or solution.

[0023] Phrases such as "in one embodiment" or "in one solution" that may appear at various points in the present description do not necessarily refer to exactly the same embodiment or solutions.

[0024] Furthermore, particular configurations, structures, or features may be combined in any suitable manner in one or more embodiments or solutions.

[0025] The references used herein are provided merely for convenience and therefore do not define the scope of protection or the extent of the embodiments.

[0026] Moreover, in the various figures, analogous references are used to indicate analogous parts or elements, without repeating for brevity the relative description for each figure.

[0027] With reference to the annexed drawings, the present invention relates to a rear suspension for a vehicle, in particular for a commercial vehicle provided with a load compartment for transporting goods to be delivered, including a load floor and two side rails 1. The rear suspension comprises a pair of longitudinal suspension arms 2, each having a main longitudinal body extending externally with respect to a respective side rail 1, along the longitudinal direction of the vehicle. With particular reference to Figure 2, each longitudinal arm 2 comprises opposite ends respectively connected to a shock absorber assembly 3 and to a rear wheel 4 of the vehicle.

[0028] According to a further feature, the rear suspension comprises a transverse connecting bar 5 extending transversely under the load floor, rigidly connected to the longitudinal suspension arms 2. As will be evident from the following description, the transverse connecting bar 5 is a hollow bar. The transverse connecting bar 5 comprises opposite end portions 5' respectively connected to a pivot 6 of the respective longitudinal arm 2. It will therefore be appreciated that the pivot 6 of the longitudinal arm 2 is obtained on the main longitudinal body of the arm, via a through opening located on the main body between the aforementioned opposite ends connected to the shock absorber assembly 3 and the rear wheel 4.

[0029] In the final assembled configuration of the suspension, each end portion 5' passes through a respective side rail 1, so as to protrude externally with respect to the side rail itself and allow the connection with the pivot 6 of the respective longitudinal arm 2 extending externally with respect to the side rail 1. In one or more embodiments, the transverse bar 5 may also be connected to the respective side rail 1 via a respective fixing portion 7, made for example in the form of a fixing flange constrained both to the transverse bar 5 and to a surface part of the rail.

[0030] According to a further feature illustrated in Figures 3,6, the rear suspension comprises two elastic devices configured as torsion bars 8 spaced inside the transverse connecting bar 5. Each torsion bar 8 is axially spaced inside a lateral part of the transverse connecting bar 5, for connection with a respective longitudinal arm 2. More particularly, each torsion bar 8 comprises an external end part on the longitudinal arm side 2 and an internal end part substantially close to the central axis of the transverse connecting bar 5. The external end part comprises a terminal end protruding externally with respect to the connecting bar 5, rigidly connected to an interface element 9 configured as a cover and connection cap. The interface element 9 is rigidly connected to an external side of the longitudinal arm 2 at the pivot 6, via one or more fixing screws. In one or more embodiments, as illustrated for example in Figures 3,4, the aforementioned terminal end is interference-coupled with an internal surface part of the interface element 9.

[0031] According to an essential feature, the rear suspension comprises a pair of actuating members 10 configured to rotate the torsion bars 8 - around their own axis - and consequently rotate the longitudinal arms 2 around the pivot 6 having at the end bearings and / or low-friction elements 14 (Figure 3).

[0032] More particularly, as illustrated in Figures 3,5,6, each torsion bar 8 has its internal end portion operatively connected to an actuating member 10. Each actuating member 10 comprises a gearmotor 10' and a worm screw 10" meshing with a nut 11 free to rotate about its axis via bearings and / or low-friction elements 13 assembled on a support body 12. The nut 11 is interference-coupled with the internal end portion of the torsion bar 8, such that rotation of the nut 11 causes rotation of the torsion bar 8. Reference 12 denotes a support body for positioning the actuating member 10.

[0033] It will therefore be appreciated that upon command of one or both actuating members 10, the torsion bars 8 can rotate about their own axis, causing rotation of the longitudinal arms 2, thereby varying the height of the load floor of a commercial vehicle. For example, in one possible operating condition, under static conditions before loading the vehicle's load compartment, the actuating members can advantageously be activated to lower the rear portion of the load floor. The main advantage thus lies in the possibility of offering on the market a commercial vehicle that makes loading / unloading operations particularly convenient. In other possible operating modes, particularly under dynamic vehicle conditions, the actuating members can advantageously be activated to raise the rear portion of the load floor, for example to increase ground clearance in case of particularly uneven road surfaces, or to improve vehicle stance under any load condition to achieve an optimal Cx "always" to reduce consumption and increase range.

[0034] The above-described solution comprising two independent actuators advantageously allows differentiating stiffness between left and right wheels, enabling vehicle body leveling when needed.

[0035] The adoption of a longitudinal arm whose rotation axis coincides with the torsion bar spring axis allows for a less invasive layout in the floor pan compared to an axle having traditional coil springs.

[0036] Naturally, while maintaining the inventive principle, construction details and embodiments may vary widely from what has been described and illustrated purely by way of example, without thereby departing from the scope of the present invention.

Claims

CLAIMS1. Rear suspension for a vehicle, in particular for a commercial vehicle provided with a load compartment for transporting goods to be delivered, wherein:- said rear suspension comprises a pair of longitudinal suspension arms (2), each having a main longitudinal body arranged to extend externally with respect to a rear portion of a respective side rail (1) of the vehicle, along the longitudinal direction of the vehicle,- each main longitudinal body comprises opposite ends respectively arranged to be connected to a shock absorber assembly (3) and to a rear wheel (4),- said rear suspension comprises a transverse connecting bar (5), arranged to extend transversely under the vehicle's load floor, including a central portion and two lateral parts each having a respective end (5') connected to a pivot (6) of the respective longitudinal arm (2), each end (5') being configured to pass through a respective side rail (1), so as to protrude externally with respect to the side rail (1) itself and allow connection with the pivot (6) of the respective longitudinal arm (2),- said rear suspension comprises two elastic devices configured as torsion bars (8), respectively spaced inside the lateral parts of the transverse connecting bar (5),- each torsion bar (8) comprises an external end portion constrained to the longitudinal arm (2) and an internal end portion,- said rear suspension comprises two independent actuating members (10) respectively configured to rotationally drive a torsion bar (8) and consequently rotate the longitudinal arm (2) about the end (5') of the transverse connecting bar (5).

2. Rear suspension according to claim 1, wherein the pivot (6) is a through opening obtained on the main longitudinal body of the arm (2), located on the main body between the opposite ends connected to the shock absorber assembly (3) and the rear wheel (4).

3. Rear suspension according to claim 1 or 2, wherein the transverse bar (5) is configured to be connected to the respective side rail (1) via a respective fixing portion (7), made in the form of a fixing flange constrained both to the transverse bar (5) and to a surface portion of the rail (1).

4. Rear suspension according to any of the preceding claims, wherein the external end portion comprises a terminal end protruding externally with respect to the connecting bar (5), interference-connected to an interface element (9) configured as a cover and connection cap constrained to the main body of the longitudinal arm (2).

5. Rear suspension according to claim 4, wherein the cover and connection cap is rigidly connected to an external side of the longitudinal arm (2) at the pivot (6), via one or more fixing screws.

6. Rear suspension according to any of the preceding claims, wherein each actuating member (10) is operatively connected to the internal end portion of the respective torsion bar (8).

7. Rear suspension according to claim 6, wherein each actuating member (10) comprises a gearmotor (10') and a worm screw (10") meshing with a nut (11) interference- coupled with the internal end portion of the torsion bar (8).

8. Vehicle comprising a load compartment for transporting goods to be delivered, a load floor, two side rails (1) and a rear suspension according to any of the preceding claims.

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