System and method for attaching a control element of an air spring with an internal height control valve

Abstract

Air suspension device for use on a driver's cab (26) of a vehicle, comprising the following: an upper arrangement (12) which is functionally assigned to the driver's cab (26); a lower arrangement (14) which is functionally associated with the vehicle; a shock absorber (18) arranged next to the upper (12) or the lower arrangement (14), wherein the shock absorber (18) has a piston rod (20) extending from there and through the other arrangement - the upper or the lower (12, 14); an air spring (10) which is attached to the upper and lower arrangement (12, 14); a flexible spring stop element (32) which is secured to the piston rod (20) next to the upper or the lower arrangement (12, 14) and is secured to the other arrangement - the upper or the lower (12, 14); a control element (28) which is functionally secured to the flexible spring stop element (32) at a first end and is slidably movable with respect to a valve (30) at a second end for controlling the opening and closing of the valve (30) depending on a distance between the upper and the lower arrangement (12, 14); and wherein the flexible spring stop element (32) is able to bend in response to rotational and / or tilting forces to which the upper or lower arrangement (12, 14) next to the flexible spring stop element (32) is subjected, in order to limit the transmission of rotational and / or tilting forces to the control element (28).

Description

AREA

[0001] The present disclosure relates to air suspension units used in regulating the height of a driver's cab of a motor vehicle, such as a truck, and in particular to an air suspension unit having a subsystem attached internally to the air suspension unit which allows an internal valve to be opened and closed as required based on a relative change in position between an upper and a lower arrangement of the air suspension unit without being affected by tilting or rotating movements of the upper arrangement relative to the lower arrangement. BACKGROUND

[0002] The statements in this section merely provide background information related to the present disclosure and may not represent the state of the art.

[0003] Truck cabs are often suspended using air suspension units. Because the load inside the cab can vary, a mechanical pneumatic valve in the air suspension unit adds or releases pressure to maintain a constant cab height. This valve regulates the pressure within the air suspension unit, thus keeping the truck cab at a generally constant height regardless of the load inside.

[0004] Typical air spring shock absorbers comprise an upper and a lower assembly, with a shock-absorbing component coupled between the two assemblies. A flexible bladder typically encloses the shock-absorbing element within a defined area. The upper assembly is usually coupled to the cab, and the lower assembly is coupled to a frame section of the vehicle. The air spring unit thus supports the cab above the vehicle frame section in such a way that the cab height can be adjusted depending on the load inside. During vehicle operation, at least a small degree of tilting or rotational movement of the upper assembly relative to the lower assembly may occur.

[0005] In conventional air spring shock absorber units, the valve used to control cab height is generally positioned away from the shock absorber itself. However, mechanisms for integrating the valve into the internal structure of the air spring shock absorber have recently become available. A major challenge with such an internally mounted valve is the mechanism required for its physical actuation. Specifically, the challenge lies in integrating the component that physically actuates the valve into the inner area of ​​the shock absorber unit. This has proven quite difficult for several reasons. Firstly, the actuating element must be able to move generally linearly with the upper assembly as it moves towards and away from the lower assembly.This is necessary so that the opening and closing of the internal valve is directly related to the height of the cab. However, if the actuator is attached directly to the upper assembly, it will be subject to the tilting and rotating movements of the upper assembly relative to the lower assembly as the cab moves back and forth with the vehicle. These cab tilting and rotating movements are problematic when the actuator is directly attached to the upper assembly (which directly supports the cab), as these movements can cause repeated bending and twisting of the actuator.Accordingly, the main challenge lies in how to integrate the actuating element into the inner area of ​​an air spring shock absorber so that it is able to detect the vertical movement of the upper arrangement relative to the lower arrangement without being significantly affected by the tilting and rotational movements of the upper arrangement relative to the lower arrangement. DE 44 09 252 A1 discloses an air suspension system with a number of air springs between a chassis and at least one vehicle component mounted to oscillate with respect to the chassis, a control valve for supplying and releasing compressed air within the air springs, wherein the control valve is actuated via an actuating device, which is characterized in that the actuating device is assigned to at least one air spring. SUMMARY

[0006] One aspect of the present disclosure relates to an air suspension device for use in a vehicle cab. The air suspension device may comprise an upper assembly, a lower assembly, a shock absorber, an bladder, a flexible bump stop, and a control element. The shock absorber is located adjacent to the upper or the lower assembly and has a piston rod extending from it and through the other assembly—the upper or the lower. The bladder is attached to both the upper and the lower assembly. The flexible bump stop is secured to the piston rod adjacent to the upper or the lower assembly and is also secured to the other assembly—the upper or the lower.The control element is functionally secured at one end to the flexible spring stop element and is slidably movable relative to a valve at the other end, controlling the opening and closing of the valve depending on the distance between the upper and lower assemblies. The flexible spring stop element is capable of bending in response to rotational and / or tilting forces to which the upper or lower assemblies are subjected, thereby limiting these forces.

[0007] Another aspect of the present disclosure relates to an air spring device for use in a vehicle cab. The device may include an upper assembly configured to be secured to a section of the vehicle cab. A lower assembly may be included, configured to be secured to a section of the vehicle such that the air spring device is positioned between the cab and the vehicle. A shock absorber is located adjacent to the lower assembly and has a piston rod extending from it. The piston rod extends through the upper assembly, and a distal portion thereof is secured to a section of the cab. An air bladder is attached to both the upper and lower assemblies. A flexible compression stop is secured to the piston rod adjacent to the upper assembly.A control element is functionally secured to the flexible suspension stop element at one end and is movable relative to a valve at the other end. This control element manages the opening and closing of the valve based on a variable distance between the upper and lower assemblies in response to a variable load in the driver's cab. The flexible suspension stop element is capable of bending in response to rotational and / or tilting forces applied to the upper assemblies, thereby limiting the transmission of these forces to the control element in response to movement of the vehicle's cab.

[0008] Another aspect of the present disclosure relates to an air spring device for use in a vehicle cab. The device can comprise an upper assembly configured to be secured to a section of the vehicle cab and a lower assembly configured to be secured to a frame section of the vehicle. In this way, the air spring device is positioned between the cab and the vehicle frame. A shock absorber is located adjacent to the lower assembly and has a piston rod projecting from it, the piston rod extending through the upper assembly and a distal portion thereof being secured to a section of the cab. An air bladder is attached to both the upper and lower assemblies. A flexible compression stop is secured to the piston rod adjacent to the upper assembly.An elongated control element is functionally secured to the flexible suspension stop element at one end and is slidably movable relative to a valve at its other end. The elongated control element is thus configured for linear movement to control the opening and closing of the valve as a function of a changing distance between the upper and lower assemblies in response to a changing load in the cab. A fastening component is arranged on the flexible suspension stop element to secure the first end of the elongated control element to the flexible suspension stop element. The bladder encloses the shock absorber, the elongated control element, and the fastening component within an internal area of ​​the bladder and simultaneously allows linear movement of the upper and lower assemblies relative to each other during shock absorber operation.The flexible suspension stop element is able to bend in response to rotational and / or tilting forces to which the upper arrangement is subjected, in order to limit the transmission of the rotational and / or tilting forces to which the upper arrangement is subjected to the elongated control element in response to a movement of the vehicle's cab.

[0009] Further areas of application are evident from the description provided here. It is understood that the description and specific examples in this summary are intended solely for illustrative purposes and are not meant to limit the scope of protection afforded by this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The drawings described here are for illustrative purposes only and are not intended to limit the scope of protection of the present disclosure in any way. Fig. Figure 1 is a detailed schematic side view of an air spring shock absorber according to an embodiment of the present disclosure; Fig. Figure 2 is a side view of only a shock absorber and an air spring shock absorber unit; and Fig. Figure 3 is a schematic block diagram showing the components of the shock absorber. Fig. Figure 2 shows a block diagram with an upper arrangement and a lower arrangement of the unit coupled. DETAILED DESCRIPTION

[0011] The following description is merely exemplary and is not intended to limit the present disclosure, application, or uses. It is understood that identical reference numerals across drawings indicate corresponding or equivalent parts and features.

[0012] With reference to Fig. Figure 1 shows a schematic view of a device in the form of an air spring shock absorber unit 10 according to an embodiment of the present disclosure (hereinafter simply referred to as the “air spring unit” 10). The air spring unit 10 can comprise an upper arrangement 12, a lower arrangement 14, a flexible bladder 16, and a shock absorber 18 mounted in the bladder 16. The shock absorber 18 has a piston rod 20 and a housing 22. Shock absorbers of this type are well known, and therefore no detailed explanation of the operation of the shock absorber 18 itself is provided.

[0013] The housing 22 of the shock absorber 18 is coupled at one end to the lower assembly 14. A rod 18a of the shock absorber 18 extends slidably through an opening 12a in the upper assembly 12. The lower assembly 14 is effectively coupled to a frame section 24 of a vehicle, which is typically a truck, as soon as a mounting section 22a of the housing 22 is secured to the frame section 24. The upper assembly 12 is effectively coupled to a section of a cab 26 of the vehicle by means of a coupling structure 20a associated with the piston rod 20. The piston rod 20 is able to move linearly in and out of the housing 22 of the shock absorber 18 in accordance with an oscillating movement of the cab 26, thus assisting in damping an up-and-down oscillation of the vehicle cab.

[0014] The air spring unit 10 further comprises a control element 28, in this example a rigid rod, which is operatively coupled to a valve 30 at one end and to a somewhat flexible compression stop element 32 at its opposite end. The control element 28 thus generally extends parallel to the piston rod 20. The compression stop element 32 can be made of rubber, elastomer, or any other material that imparts a degree of flexibility and deflection to the element. The compression stop element 32 is secured to the piston rod 20 next to the upper arrangement 12, for example, by an adhesive, an interference fit, or any other suitable means.The suspension stop element 32 is thus able to bend and twist slightly when the upper arrangement 12 is subjected to tilting and torsional forces exerted by movement of the vehicle's cab 26 during vehicle operation. The suspension stop element 32 therefore helps to prevent the transmission of these tilting and torsional forces to the control element 28 without otherwise affecting the unimpeded linear movement of the control element 28.

[0015] Fig. Figure 2 shows the air spring unit 10 without the flexible bladder 16, and Fig. Figure 3 shows an enlarged, simplified cross-sectional view of the compression stop element 32 and a section of the control element 28 attached thereto. The control element 28 may include a fastening component 34 having a bore 35 configured to receive the compression stop element 32. The fastening component 34 permanently secures a rod 36 of the control element 28 to the compression stop element 32. In this embodiment, a threaded screw 40 inserted into a threaded bore 42 of the fastening component 34 is used to fasten the control element 28 to the fastening component 34. However, it is understood that any other suitable fastening arrangement may be used. A distal section 44 of the rod 36 is located with respect to the valve 30 (where the valve 30 is in Fig.(1 is visible) movable. In this way, a linear movement of the control element 28 along the axis defined by the arrow 46 controls the valve 30, depending on the distance between the upper arrangement 12 and the lower arrangement 14, either introducing air into the inner area of ​​the bladder 16 or releasing air in the bladder 16 to the atmosphere.

[0016] In this example, the compression stop element 32 has a circumferential channel 48 formed on its outer surface and a bore 50 extending axially through it. The bore 50 receives a section of the piston rod 20. The circumferential channel 48 receives a radially inwardly extending section 52 of the fastening component 34, thereby securing the fastening component to it by frictional engagement. Again, any other suitable fastening means can be used. Several circumferentially spaced, radially inwardly extending projections 54 provide support for holding the compression stop element 32 to the piston rod 20 in an interference fit.

[0017] A key feature of the air spring unit 10 is that, due to the flexibility and compressibility of the compression stop element 32, it absorbs a degree of tilting and torsional forces on the upper assembly 12 without transmitting such forces to the control element 28, or transmitting only a drastically reduced percentage of such forces. In both cases, the control element 28 is generally able to move along a linear path, even when tilting and torsional forces are applied to the upper assembly 12. This ensures that proper linear movement of the control element 28 is maintained regardless of external tilting and torsional forces applied to the air spring unit 10.

[0018] It is understood, however, that although the air suspension unit 10 has been described in connection with the cab of a truck, the air suspension unit is not limited to use exclusively in trucks. Any vehicle that has a passenger compartment supported on it and subjected to vibration relative to the vehicle frame can potentially make use of the air suspension unit 10. Accordingly, large vehicles, such as those used in commercial agriculture, which are driven by people, as well as large excavating and earthmoving machines, tracked snow groomers, etc., to name just a few other types of vehicles, can also potentially benefit from the features of the air suspension unit 10.

[0019] The air spring unit 10 of the present disclosure thus overcomes a considerable limitation of earlier designs in which attempts were made to position a control element within a bladder of the unit. The features of the air spring unit 10 as described herein do not significantly increase the overall cost of the air spring unit, nor do they significantly increase the overall weight of the air spring unit, nor do they significantly increase the manufacturing or assembly complexity.

[0020] Although various embodiments have been described, modifications or variations are obvious to the person skilled in the art that can be carried out without departing from the present disclosure. The examples illustrate the different embodiments and are not intended to limit the present disclosure. Therefore, the description and the claims are to be interpreted broadly and only with such limitations as are necessary in view of the relevant prior art.

Claims

[1] Air suspension device for use in a cab (26) of a vehicle, comprising: an upper assembly (12) functionally associated with the cab (26); a lower assembly (14) functionally associated with the vehicle; a shock absorber (18) disposed adjacent to one of the upper (12) and lower (14) assemblies, the shock absorber (18) having a piston rod (20) projecting therefrom and extending through the other of the upper and lower (12, 14) assemblies; an air spring (10) attached to the upper and lower assemblies (12, 14); a flexible compression stop element (32) secured to the piston rod (20) adjacent to one of the upper and lower arrangements (12, 14) and secured to the other of the upper and lower arrangements (12, 14); a control member (28) operatively secured to the flexible jounce stop member (32) at a first end and slidably movable relative to a valve (30) at a second end for controlling the opening and closing of the valve (30) in dependence upon a distance between the upper and lower assemblies (12, 14); and wherein the flexible jounce stop element (32) is capable of deflecting in response to rotational and / or tilting forces to which the upper or lower assembly (12, 14) adjacent to the flexible jounce stop element (32) is subjected, in order to limit the transmission of the rotational and / or tilting forces to the control element (28). [2] The air spring device of claim 1, further comprising a mounting component (34) for securing the control member (28) to the flexible jounce stop member (32). [3] Air spring device according to claim 2, wherein: the flexible spring deflection stop element (32) comprises a channel (48); and the fastening component (34) comprises a radially inwardly projecting projection (54) which frictionally engages the channel (48) of the flexible jounce stop element (32) for securing the flexible jounce stop element (32) thereto. [4] The air spring device according to claim 1, wherein the piston rod (20) includes a coupling structure (20a) at a distal end thereof for securing to a portion of the driver's cab (26). [5] The air spring device according to claim 1, wherein the shock absorber (18) includes a mounting portion (22a) for securing to a portion of the vehicle. [6] Air spring device according to claim 1, wherein the control element (28) comprises a rigid rod arranged parallel to the piston rod (20). [7] Air spring device according to claim 1, wherein the flexible deflection stop element (32) is composed of elastomer. [8] Air spring device according to claim 1 for use in a driver's cab (26) of a vehicle: wherein the upper assembly (12) is configured to be secured to a portion of the cab (26) of the vehicle; wherein the lower assembly (14) is configured to be secured to a portion of the vehicle such that the air spring device is disposed between the cab (26) and the vehicle; wherein the piston rod of the shock absorber extends through the upper assembly (12) and a distal portion thereof is secured to a portion of the cab (26); wherein the control element (28) is slidably movable in response to a varying load in the cab (26). [9] Air spring device according to claim 8, wherein the fastening component (34) comprises a bore for receiving the flexible deflection stop element (32). [10] The air spring device according to claim 8, wherein the flexible compression stop member (32) is configured to be press-fitted onto the piston rod (20). [11] Air spring device according to claim 8, wherein the control element (28) is secured to the fastening component (34) via a member at the first end thereof. [12] An air spring device according to claim 8, wherein the flexible jounce stop element (32) comprises a bore (50) and is press-fitted onto the piston rod (20) at a location adjacent to the upper assembly (12). [13] The air spring device of claim 9, wherein the fastening component (34) is press-fitted onto the flexible deflection stop element (32). [14] The air spring device of claim 13, wherein the elongate control member (28) is secured at the first end thereof with a threaded screw (40) to a portion of the mounting component (34) such that the elongate control member (28) extends generally parallel to the piston rod (20).

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