Suspension system for heavy vehicles

Abstract

A suspension system for a heavy vehicle, the heavy vehicle being provided with a frame connected to a plurality of wheels carried in pairs by respective axles, for each side of the vehicle, the suspension system comprising a first upper connecting element and a first lower connecting element and a second upper connecting element and a second lower connecting element, each of the connecting elements being connected at an end of the connecting element to one of the axles and to a stabilizer bar movably carried by the frame by means of respective movable connecting members, at least one of the movable connecting members being freely rotatable about three mutually perpendicular axes.

Description

[0001] Cross - reference to related applications

[0002] This patent application claims the priority of Italian Patent Application no. 102019000002405, filed on February 19, 2019, the entire disclosure of which is incorporated herein by reference. Technical field

[0003] The present invention relates to vehicle suspension systems, and particularly to "tandem" suspension systems for heavy vehicles. Background art

[0004] The suspension of heavy vehicles - especially those used for heavy transport in harsh conditions such as mines or plantations - needs to be strong enough, while ensuring characteristics such as damping, stiffness, and weight, so that the vehicle can be easily driven.

[0005] To meet this need, an improved suspension system was developed and disclosed in Patent BR1020160148936.

[0006] This suspension system is a "tandem" suspension system, that is, a system in which two axles of the vehicle are connected to each other and to the vehicle's frame through the suspension system itself.

[0007] Basically, for each right and left side of the two axles, the described suspension system includes a pair of connecting elements, each connecting element being connected at its end portions to one of the axles and to a stabilizer bar movably carried by the vehicle's frame, said end portions being connected to their respective elements by means of movable connectors.

[0008] This type of system ensures very good performance of the suspension system in terms of damping and stiffness, which makes the vehicle easy to drive. Such a system with very good suspension performance can be used especially for extremely heavy vehicles and / or difficult roads, such as off - road roads, despite the limited weight of the system. In addition, since the elements of this suspension are easy to manufacture and identical to each other, the system is economical and easy to assemble.

[0009] However, the movable connectors between the connecting elements and the axles and / or the frame tend to wear and break during vehicle use. In addition, the movable connectors cannot be used for vehicles with different postures and need to be redesigned accordingly.

[0010] Therefore, there is a need for a suspension system for heavy vehicles that can solve the problems discussed above.

[0011] The object of the present invention is to meet the needs discussed above. Summary of the invention

[0012] The above object is achieved by a suspension according to the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] With reference to the drawings, the present invention will be best understood after a perusal of the following detailed description of a preferred embodiment, which is provided by way of non-limiting example, in which:

[0014] · Figure 1 is a perspective view of a vehicle showing a vehicle frame and a suspension system according to the present invention;

[0015] · Figure 2 is a perspective view of a suspension system according to the present invention;

[0016] · Figure 3 is a perspective view of a suspension system according to the present invention, with some parts removed for greater clarity;

[0017] · Figure 4 is an enlarged perspective view of a part of a suspension system according to the present invention;

[0018] · Figure 5A is a schematic cross-sectional view of a connecting element of a suspension system according to the present invention; and

[0019] · Figure 5B is Figure 5A a schematic cross-sectional view of an alternative embodiment of an element of. DETAILED DESCRIPTION

[0020] Figure 1 There is shown a vehicle 1 which includes a known vehicle frame 2 substantially including a pair of longitudinal members 2a, 2b and a plurality of wheels 3 carried in pairs by respective axles 4.

[0021] The vehicle 1 further includes a suspension system 5 according to the present invention, which is configured to connect at least two axles 4 to the vehicle frame 2, as described below.

[0022] For the present, reference will be made to a single side of the suspension system 5, for example, the right side of the suspension system 5 relative to the driving direction along the longitudinal axis A of the vehicle 1, as Figure 2 shown in.

[0023] The suspension system 5 substantially includes two pairs of connecting elements 6, 7, namely a first upper connecting element 6a and a first lower connecting element 6b and a second upper connecting element 7a and a second lower connecting element 7b, each of the connecting elements being connected at a first end of its ends to one of the axles 4 and at a second end opposite the first end to a stabilizer bar 10 movably carried by the vehicle frame 2.

[0024] These connectors connecting the ends of the connecting elements 6, 7 are movable connectors, as described below, and according to the invention, at least one of these connectors has the possibility of rotating about three mutually perpendicular axes, in particular about an axis A' parallel to the axis A, about a vertical axis B, and about an axis C perpendicular to the axes A' and B.

[0025] On the left side - as can be partially inferred from Figure 2 and can be better seen in Figure 3 the suspension system 5 is mirror-shaped relative to the right side and has a staggered structure. This means that if on one side, for example on the right side, the ends of the connecting elements 6, 7, such as the first rear upper element 6a, are connected to the axle 4, on the left side, the end of the second rear connecting element 7a is connected to the axle 4 in the upper position, and this applies to all four combinations of sides and positions.

[0026] Each first upper connecting element 6a and first lower connecting element 6b advantageously includes a metal torsion bar 9. Referring to a single stabilizer bar 9, such as the stabilizer bar 9 of the first upper connecting element 6a, which includes a first end 9a and a second end 9b, the first end 9a is movably connected by means of a first movable connector 11 to an upper stabilizer bar 10a, which is supported so that it can freely rotate about a longitudinal axis C' parallel to the axle 4 of the upper stabilizer bar 10a between the side members 8a, 8b, and the second end 9b is movably connected by means of a second movable connector 12 to the axle 4.

[0027] Similarly, each second upper connecting element 7a and second lower connecting element 7b advantageously includes a metal thrust bearing bar 13. Referring to a single thrust bearing bar 13, such as the thrust bearing bar 13 of the second lower connecting element 7b, which includes a first end 13a and a second end 13b, the first end 13a is movably connected by means of a first movable connector 14 to a lower stabilizer bar 10b, which is supported so that it can freely rotate about a longitudinal axis C' parallel to the axle 4 of the lower stabilizer bar 10b between the side members 8a, 8b, and the second end 13b is movably connected by means of a second movable connector 15 to the axle 4.

[0028] According to the embodiments described herein, the second movable connection member is a connection member provided with all rotational degrees of freedom, while the movable connection members 11, 14, and 15 are hinges having a single rotational degree. In particular, the movable connection members 11, 14, and 15 are hinges that allow the respective ends to rotate about the following rotational axes: these rotational axes are parallel to each other and perpendicular to the longitudinal axis A of the vehicle. These hinges are advantageously hinges between metal elements or hinges obtained by means of bushings.

[0029] As described above, the second movable connection member 12 is configured to allow the respective ends 9b of the torsion bar 9 to have full rotational freedom about the above-mentioned axes A', B, and C.

[0030] In particular, the movable connection member 12 includes a ball joint 13, which is carried by a support member 14, and the support member 14 is connected to the axle 4 by means of a hinge 15 for free rotation. The hinge 15 advantageously allows the support member 14 to rotate about an axis A' perpendicular to the longitudinal axis of the respective axle 4.

[0031] Figure 5A 、 Figure 5B Two embodiments of the movable connection member 12 for different attitudes of the vehicle are shown. Except for the height of the support member 14 and the manner of manufacturing the hinge 15, the movable connection members 12 are identical to each other, as described below.

[0032] In both embodiments, the ball joint 13 includes a rolling sphere 16, which is received in a dedicated opening 17 obtained at the end 9b of the torsion bar 9. The ball joint 13 further includes an anchoring portion 18, which is connected to the rolling sphere 16 and is preferably manufactured as a single piece with the rolling sphere 16.

[0033] The anchoring portion 18 extends vertically from the rolling sphere 16 towards the axle 4 into a hole 19 formed in the support member 14, and the hole has dimensions complementary to the external shape of the anchoring portion 18.

[0034] The anchoring portion 18 is configured to define a reversible mechanical coupling with the support member 14. In particular, in the embodiments described herein, the anchoring portion 18 internally defines a threaded seat 21, which is configured to cooperate with a threaded element 22. In particular, the threaded element 22 is configured to pass through the bottom wall 19a of the hole 19 and through a hole 23 formed in the support member 14 on the opposite side of the hole 19 with respect to the wall 19a.

[0035] The support member 14 substantially has a prismatic shape, is preferably made in one piece and is made of a metallic material such as steel. The support member 14 is carried movably by the axle 4 by means of a hinge 15 formed between a pair of flanges 24 which extend vertically outside the axle 4 and are spaced apart from each other by a certain distance to allow the support member 14 to be inserted with a clearance.

[0036] According to Figure 5A the embodiment, the support member 14 extends more in the vertical direction than Figure 5B the support member 14 of. In addition, the support member 14 further includes a through hole 25 passing through the entire support member 14 and perpendicular to the holes 19 and 23. The hole 25 is coaxial with a pair of holes 26, each hole 26 being formed in one of the flanges 24.

[0037] The holes 25 and 26 are configured to receive a pin 27 inside, and the pin 27 defines an outer surface which is designed to cooperate in a sliding manner with respect to the body 14, thus establishing the hinge 15. The pin 27 advantageously includes an end portion 27a extending through one of the flanges 24, and the end portion 27a is preferably threaded and configured to cooperate with a nut 28 to fix the pin 27 to the flange 24.

[0038] According to Figure 5B the embodiment, as described above, the support member 14 extends less in the vertical direction than Figure 5B the support member 14 of, and the support member 14 includes a pair of blind holes 31 extending perpendicularly to the holes 19 and 23 inside the support member 14. Just like Figure 5A in the case of, the flange 24 is provided with a through hole 26 passing through the flange 24.

[0039] In this configuration, the hinge 15 is defined by a pair of pins 32 including an intermediate threaded portion 32a and end portions 32b, the intermediate threaded portion 32a being configured to cooperate with the respective threads obtained inside the holes 26, and the end portions 32b being configured to be received slidably inside the holes 31 of the support member 14.

[0040] According to a further aspect of the present invention, the torsion bar 9 has a cross-section varying along the longitudinal axis S of the torsion bar 9.

[0041] In particular, the torsion bar 9 has a cross-section, preferably a cross-section having a substantially trapezoidal shape, which varies from a cross-sectional area having a maximum value at the first end 9a to a cross-sectional area having a minimum value at the second end 9b along the axis D. In particular, when looking at the torsion bar 9 from the side, the upper edge and the lower edge of the torsion bar 9 approach each other from the end 9a to the end 9b, and similarly, when looking at the torsion bar 9 in the axial direction, the right edge and the left edge of the torsion bar 9 approach each other from the end 9a to the end 9b.

[0042] The above-described embodiment of the suspension system 5 functions in the following manner.

[0043] When the wheel 1 is subjected to a force towards the vehicle's frame 2, or the vehicle's frame 2 is subjected to a force towards the wheel 1, the elements constituting the suspension allow these pressures to be damped, thus preventing these loads from being transmitted to the frame 2 and, consequently, to the vehicle and to the vehicle's driver.

[0044] In particular, despite the limited weight, the shape and relative position of the above elements allow for ideal damping under all dynamic conditions and / or positions.

[0045] More specifically, the thrust bearing rod 13 allows the movement of the axle 4 along the longitudinal axis A of the vehicle to be restricted, while the connection between the torsion bar 9 and the stabilizer bar 10 between the two axles 4 and the frame 2 causes the torque to act in the other two axis directions perpendicular to the axis A.

[0046] Due to the fact that the connection member 12 has all rotational degrees of freedom, it is possible to have a smaller pressure load in this area, resulting in a longer connection time and a reduced thickness of the stabilizer bar.

[0047] For the above reasons, the advantages of the suspension system 5 according to the present invention are obvious.

[0048] Due to the use of the movable connection member 12 that can rotate around all rotational axes, a larger load is supported by the remaining metal connection members, and thus, it can last longer.

[0049] In addition, this state of smaller load allows for a reduction in the cross-section of the torsion bar 9 at the end of the movable connection member 12, making the suspension system 5 lighter in weight and lower in manufacturing cost.

[0050] Generally speaking, despite maintaining a low manufacturing cost and a small weight, the structure of the suspension system 5 can withstand large loads while ensuring good drivability of the vehicle under adverse road conditions.

[0051] Furthermore, the specific configuration of the movable connection member 12 with total rotational degrees of freedom allows the same axle 4 and the same suspension system 5 to be used for different postures of the vehicle. Due to the mass production of identical elements, changing the sole support 14 subsequently saves costs.

[0052] Finally, changes and variations can be made to the suspension system 5 according to the present invention, but without exceeding the scope of protection set forth in the appended claims.

[0053] For example, the shape of the movable connection member and the connection elements 6 and 7 described herein can be changed according to what is claimed herein.

[0054] In addition, depending on the type and tonnage of the vehicle, there may be more components than those described above.

Claims

1. A suspension system (5) for a heavy vehicle (1), the heavy vehicle (1) being provided with a frame (2) connected to a plurality of wheels (3) carried in pairs by respective axles (4), for each side of the vehicle (1), the suspension system (5) comprising a first upper connecting element (6a) and a first lower connecting element (6b) and a second upper connecting element (7a) and a second lower connecting element (7b), each of the connecting elements (6, 7) being connected at the end of the connecting element to one of the axles (4) by means of respective movable connecting members (11, 12, 14, 15) and to a stabilizer bar (10) movably carried by the frame (2), at least one of the movable connecting members (11, 12, 14, 15) being free to rotate about three mutually perpendicular axes. wherein, The remaining said movable connectors (11, 14, 15) include a first hinge, the first hinge allowing respective ends of the connecting elements (6, 7) to rotate about axes all parallel to each other, and wherein, the at least one movable connector (12) includes a spherical joint carried by a support (14) movably carried by respective axles (4) of the vehicle (1) by means of a second hinge.

2. The suspension system according to claim 1, wherein, The first upper connecting element (6a) and the first lower connecting element (6b) include a torsion bar (9).

3. The suspension system according to claim 1, wherein, The second upper connecting element (7a) and the second lower connecting element (7b) include a thrust bearing bar (13).

4. The suspension system according to claim 1, wherein, The spherical joint can be reversibly connected to the support (14).

5. The suspension system according to claim 1, wherein, The second hinge between the support (14) and the axle (4) includes a pin (27), the pin (27) passing through the support (14) and being reversibly fixed to the axle (4).

6. The suspension system according to claim 1, wherein, The second hinge between the support (14) and the axle (4) includes a pair of pins (32), the pins (32) being configured to be blindly inserted into the support (14), the pins (32) being reversibly fixed to the axle (4).

7. The suspension system according to claim 2, wherein, The torsion bar (9) has a cross-section that varies along the longitudinal axis of the torsion bar.

8. The suspension system according to claim 7, wherein, The cross-section varies from a maximum at the end (9b) connected to the stabilizer bar (10) to a minimum at the end (9a) connected to the axle (4).

9. A heavy vehicle (1) provided with a frame (2) connected to a plurality of wheels (3) carried in pairs by respective axles (4), the axles (4) being connected to the frame (2) by means of the suspension system according to claim 1.

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