DE102021207638A1 - Protective device for an additional spring device - Google Patents

Abstract

The invention relates to a protective device for an additional spring device (10) on an axle construction of a vehicle, in which an air cushion is briefly built up during a compression process in order to implement overload protection for the chassis. For this purpose, a stop ring (20) is provided, which is arranged on a base (16) of the additional spring device (10) and has and/or forms at least one air outlet (24), so that defined flow conditions can be set. For slow compression and rebound of the axle construction, the flow conditions can be set in such a way that the suction and pressure effects that occur have a cleaning effect on the additional spring device (10).

Description

The invention relates to a protective device for an additional spring device on an axle construction of a vehicle, in which an air cushion is briefly built up during a compression process in order to implement overload protection for the chassis. For this purpose, a stop ring is provided, which is arranged on a base of the additional spring device and has and/or forms at least one air outlet, so that defined flow conditions can be set. For slow compression and rebound of the axle construction, the flow conditions can be set in such a way that the suction and pressure effects that occur have a cleaning effect on the additional spring device.

In order to increase driving comfort and to support the coil springs on vehicle axle constructions, in particular to absorb high loads, a so-called auxiliary spring is provided on almost all axle constructions on the market. Depending on the axle concept, this can be designed as part of the top mount or act as an independent component of the axle.

To protect against mechanical overload, the prior art usually works on a direct reinforcement of the auxiliary spring. This can happen through a material substitution (e.g. with higher-strength material), a modification (e.g. a change in geometry), partial reinforcement through additional reinforcement on the relevant components or through a change in the load path. In the case of the additional spring on an axle device, the spring deflection and the load application should be limited to protect against overstressing.

The object of the invention is to propose a simple solution for protecting against overloading of additional spring devices on axle structures of vehicles, which can preferably be implemented inexpensively.

The object of the invention is achieved with a protective device according to claim 1 and a vehicle according to claim 10. Further preferred refinements of the invention result from the remaining features mentioned in the dependent claims.

A protective device according to the invention is provided for an auxiliary spring device on an axle structure of a vehicle, the auxiliary spring device being formed with an auxiliary spring mount, an auxiliary spring, a base and an at least partially foldable protective tube, and the auxiliary spring mount holding the auxiliary spring, the at least partially foldable protective tube on the Auxiliary spring receptacle is arranged in such a way that it at least partially encloses the auxiliary spring and the base is arranged relative to the auxiliary spring in such a way that when the axle construction deflects, the auxiliary spring hits the base and is compressed and/or the auxiliary spring is connected to the base and through the deflection of the axle construction is compressed.

A groove is formed at least in sections along the circumference of the base and a stop ring is arranged on the base in such a way that it engages with the groove and forms a stop for the at least partially foldable protective tube. The stop ring has at least one air outlet and/or forms at least one air outlet in order to set flow states in a targeted manner during a spring action of the axle construction.

As already stated, axle constructions of vehicles are generally provided with an additional spring device to support the helical spring. It is formed with an additional spring mount, which accommodates and holds the actual additional spring, i.e. fixes it in its position. It also has a so-called base. This serves to compress the auxiliary spring during deflection. To do this, the base must be arranged in such a way that the auxiliary spring hits it when the axle construction deflects and can be compressed. As an alternative or in addition, the auxiliary spring can be connected to the base and compressed during a compression process. Such a base usually has a round cross section.

To protect against contamination of the auxiliary spring and damage associated therewith, auxiliary spring devices have a protective tube which can be folded at least partially in order to allow compression and rebound processes and angular movements of the auxiliary spring device resulting therefrom. For this purpose, sections of the protective tube can be designed with a fold structure in the sense of a bellows. It can also be designed as a whole as a bellows. The at least partially foldable protective tube therefore does not impede the compression process of the auxiliary spring. Known bellows are formed from or with plastics such as polypropylene (PP) or ethylene-propylene-diene rubber (EPDM). The protective tube is arranged on the auxiliary spring mount. It should be designed and arranged in such a way that it at least partially encloses the auxiliary spring in order to achieve the protective effect described. the Arrangement of the protective tube may include a fixture.

According to the invention, a groove is formed at least in sections along the circumference of the base and a stop ring is arranged on the base in such a way that it engages with the groove and forms a stop for the at least partially foldable protective tube. Said groove should therefore run circumferentially or at least in sections circumferentially around the base and thus provide fixing points for the stop ring. The groove thus serves to accommodate and/or secure the position of the stop ring.

This is thus placed on the base and brought into engagement with the groove. It protrudes beyond the circumference of the base to such an extent that it forms a stop for the protective tube during a spring deflection process. The protective tube is supported by the contact between the protective tube and the stop ring and is folded up in the foldable areas, but the system of the additional spring device is also sealed. The protective tube does not have to be connected or fixed to the stop ring.

According to the invention, the stop ring is designed in such a way that it has and/or forms at least one air outlet in order to specifically set desired flow conditions in the area of the auxiliary spring during a spring operation of the axle construction. These flow conditions arise when air is displaced from the system by compressing the protective tube and the displacement is influenced or limited by the stop ring. The stop ring acts in the sense of a flow control unit and can also be referred to as a control ring. However, the flow conditions are controlled or influenced solely by the at least one air outlet, ie purely by the geometric configuration of the stop ring.

At least one air outlet is provided, preferably a large number of air outlets, which influence the flow conditions as desired due to their design, as will be explained in more detail below. The at least one air outlet can be formed in the stop ring, for example in the form of recesses or bores. However, the at least one air outlet can alternatively or additionally be formed by means of the stop ring, for example in that the stop ring and the base form or form or delimit the at least one air outlet in the installed state.

A defined flow resistance can thus be provided by the stop ring provided according to the invention, which leads to a flow deceleration and to a transition to a laminar flow. As a result, an air cushion is briefly formed during the compression of the axle construction, which protects against mechanical overload. This proves to be particularly advantageous in the case of rapid compression processes, such as when driving over obstacles or potholes, since the air in the system of the additional spring device cannot suddenly escape. In particular, if each additional spring of a vehicle is designed with such a protective device, the chassis is protected against overloading.

With a slow compression or rebound, defined flow conditions arise that can be adjusted in such a way that the interior of the additional spring device is cleaned by the resulting suction and pressure effects by dirt, particles and/or snow being blown out.

The proposed solution ensures that the spring deflection and the load application are limited during a compression process. This protection against mechanical overload is self-regulating, in particular depending on the speed of the spring process, is simple in construction and therefore inexpensive. A guide by a piston rod is not required.

The additional spring is preferably a stop buffer. Such a stop buffer should be designed in terms of geometry and material selection in such a way that it has the desired spring properties. It is desirable here if the stop buffer designed as an additional spring and the base have shapes that correspond to one another at least in some areas, so that the impact and compression of the stop buffer can take place as desired. The stop buffer can in particular be formed with a foamed polyurethane (PUR), it also being possible to influence the resilience of the stop buffer by the specific selection of the properties of the polyurethane.

In a next preferred embodiment of the protective device according to the invention, the stop ring is formed with an outer ring and lamellae, the lamellae spacing the outer ring from the base and at least one air outlet being formed by the outer ring, the lamellae and the base. A stop ring is therefore provided which does not form full-circumferential touching contact with the periphery of the base.

The stop ring according to this embodiment consists of an outer ring from which lamellae, ie at least two lamellae, preferably a large number of lamellae, extend in the direction of the base. On the one hand, these lamellae serve to support the outer ring against the base and to space its position by engaging with the groove. In this embodiment of the invention, the groove can be formed in particular in sections in the areas in which the lamellae are provided.

The distance between the outer ring and the base is influenced by the geometric design of the lamellae. Lamellae are protuberances, webs or the like, which emanate from the outer ring and protrude in the direction of the base. They can be oriented radially, but they can also be oriented at one or more angles with respect to the outer ring. The lamellae are preferably formed in one piece with the outer ring, but they can also be attached to the outer ring.

On the other hand, the lamellae serve to form the at least one air outlet together with the sections of the outer ring lying between them and the circumference or the contour of the base. An air outlet formed in this way is limited by a section of the outer ring, lamellae and the base.

A further preferred embodiment of the invention is when the flow conditions are to be set by the number, shape, size, position, orientation and/or variance of the at least one air outlet. Regardless of whether the at least one air outlet is provided solely by means of the stop ring or in conjunction with the stop ring and other components, the specific design of the stop ring and therefore the air outlets influence the resulting flow conditions during compression and/or rebound processes.

A large number of small air outlets and a small number of larger air outlets can basically form an essentially the same outlet area, but with a large number of small air outlets there can be more turbulence in the air flowing through, which may have a negative effect on the air flow. However, turbulence can also be desired, for example in order to loosen and blow out dirt in the additional spring device.

If a large outlet area is provided by the size of the air outlets and/or their number, the air cushion to be formed may not be provided with a sufficient counterforce, or may be shorter or not provided at all. Therefore, depending on the mechanical loads to be expected during compression and/or rebound processes, it must be determined which counterforce should be provided by the air cushion and how long it should be maintained.

In addition to the number and/or the size of the air outlets, the flow conditions are also influenced by their shape and/or alignment. The shape relates to the geometric shape in all three spatial axes. The orientation describes whether the at least one air outlet is inclined at (in each case) an angle of inclination in relation to the central axis of the stop ring. Finally, the position of the at least one air outlet can also influence the guidance of the inflowing and/or outflowing air during a spring process, for example in order to promote the loosening and blowing out of dirt and/or particles from the additional spring device in a targeted manner.

When there are several air outlets, not all of them have to be designed and/or provided in the same way. The air outlets can differ from each other in all of the features explained above in order to set the flow volume, the flow direction and/or the flow speed for the respective axle construction in a targeted manner.

By defining the features of the at least one air outlet as described above, the effect can be adjusted as desired in the application, taking into account influencing factors such as the weight of the vehicle, expected forces acting in particular in the event of sudden deflection, available spring travel and the like, the protective effect of the protective device according to the invention can be specifically adjusted and thus can be adapted to the vehicle and optionally its planned area of application.

In particular, the number, the shape, the size, the position, the orientation and/or the variance of the at least one air outlet can be selected in order to prevent the protective tube from bursting. With knowledge of the possible load cases when compressing and/or rebounding the axle construction, a minimum area of the at least one air outlet can be determined, which is required to discharge the air to be displaced without damaging the protective tube. In this case, turbulence effects, which primarily result from the number, size, shape and/or orientation of the at least one air outlet, can also be taken into account or even used in a targeted manner.

In order to ensure that the at least partially foldable protective tube hits the stop ring in such a way that it can effectively develop its sealing effect in the contact area and the air flows in and/or out only through the at least one air outlet, it is advantageous if the at least partially collapsible protective tube is formed at its end directed towards the base with a funnel-like opening. By the funnel-like opening is meant that the cross-section of the protective tube is expanded at the end that meets the stop ring and its radius reduces with increasing distance from the stop ring. This can ensure that the protective tube is guided on and over the base and is inevitably guided onto the stop ring in such a way that a full-surface and effective stop is effected, which is required for folding the protective tube and the desired flow conditions.

If the at least partially foldable protective tube is designed as a bellows of a known type, the funnel-shaped design of the end facing the base can be realized by a corresponding cut in the last fold of the bellows.

In order to prevent dirt, snow and the like from penetrating through the at least one air outlet into the stop ring and/or blocking it, the at least one air outlet can be designed with a dirt guard to prevent dirt from penetrating. In this context, penetrating dirt should be understood to mean any material that could pass through the at least one air outlet from the outside and penetrate into the additional spring device, i.e. in addition to road dirt all types of particles, snow, road salt, water and the like. In order not to impair the function of the at least one air outlet, it must be ensured that the dirt guard prevents or at least reduces the ingress of dirt, but does not impair the escape of air as a result of deflection. Accordingly, the dirt protection must be permeable at least for the outflowing air.

In particular, valves and/or flaps can be used to protect against dirt, which are designed and arranged in such a way that they open to the outside when air flowing out of the additional spring device flows against them and remain closed when air flowing in meets them. A skin or cover or wings formed with a plastic can act in a similar way, which remain closed when air flows in and open when air flows out and allow the air flow to escape.

Alternatively or additionally, air-permeable fillers can be provided in the at least one air outlet or at least in its immediate vicinity, through which the penetrating air must flow before it penetrates into the additional spring device. Dirt and the like should or can be filtered out by these air-permeable fillers. Such an air-permeable filler can be a felt that is arranged in or in front of the at least one air passage.

The described cleaning effect of the penetrating air can also be achieved with brushes or brushes that are arranged in or in front of an air outlet.

Since the proposed elements can also form a flow resistance for the outflowing air, it is advisable to take this into account when dimensioning the stop ring and the air outlets provided therein.

The stop ring can preferably be formed from a plastic, in particular a polyoxymethylene or a polyamide. Plastics are flexibly formable and light materials that can be individually adjusted to the prevailing conditions. Polyoxymethylene (POM) is a semi-crystalline thermoplastic whose properties make it ideal for use in automotive engineering. It has good mechanical properties, high dimensional stability and very good wear behavior. The use of polyamide (PA) is also advantageous because polyamide is also a strong and tough material.

In a preferred embodiment, the stop ring can be produced by means of an injection molding process or 3D printing. 3D printing enables objects such as the stop ring to be individually manufactured and thus also to be individually adapted to the axle construction or the vehicle for which it will be used. For production in large numbers, the stop ring can be produced by means of an injection molding process, in which molded parts that can be used directly can be produced in large numbers at low cost.

In addition to the protective device according to the invention, a vehicle is also claimed in which at least one axle device has one of the protective device according to the invention.

With the protective device according to the invention, mechanical overloading of an axle construction of a vehicle can be prevented by limiting the spring deflection and the load application. By means of the stop ring provided, the protection is easily achieved effect achieved. In addition, a cleaning effect can be realized within the additional spring device. Due to the specific design of the stop ring and its at least one air outlet, the flow conditions of the additional spring device can be set individually and as required.

Unless stated otherwise in the individual case, the various embodiments of the invention mentioned in this application can advantageously be combined with one another.

• 1 eine Achskonstruktion einer Hinterachse eines Fahrzeugs mit Zusatzfederei nri chtung,
• 2 eine Zusatzfedereinrichtung beim Einfedern,
• 3 eine Zusatzfedereinrichtung mit erfindungsgemäßer Schutzvorrichtung,
• 4 eine erste beispielhafte Ausgestaltung eines Anschlagringes, und
• 5 eine zweite beispielhafte Ausgestaltung eines Anschlagringes.

The invention is explained below in exemplary embodiments with reference to the associated drawings. Show it:

• 1 an axle construction of a rear axle of a vehicle with additional spring device,
• 2 an additional spring device when deflecting,
• 3 an additional spring device with a protective device according to the invention,
• 4 a first exemplary embodiment of a stop ring, and
• 5 a second exemplary embodiment of a stop ring.

1 shows a rear axle construction of a vehicle with a coil spring 50 and an additional spring device 10 with an additional spring receptacle 12, an additional spring 14 and a base 16, as is known from the prior art. The additional spring 14 is in the form of a stop buffer made of foamed polyurethane (PUR).

A protective tube 18 is often provided on the additional spring receptacle 12, which is at least partially foldable or designed as a bellows. This is shown in the schematic sectional view of 2 visible, where only the additional spring device 10 is shown there and already supplemented by features of the protective device according to the invention.

An example is in 2 the protective tube 18 is designed as a bellows, which is only designed with a non-foldable area in the area of the arrangement on the additional spring receptacle 12 in order to ensure a secure hold there. The additional spring device 10 in 2 is shown in a compression process.

The base 16 of the additional spring device 10 interacts with the link 52, as a result of which the arcuate movement indicated by the arrow is generated. The stop buffer 14 hits the base 16 and is compressed. By using a bellows as the protective tube 18 or a partially foldable protective tube, the arcuate movement of the link 52 and the compression of the bump stop 14 can take place without restriction during compression.

A groove 19 is formed along the periphery of the pad 16 and extends circumferentially around the entire pad 16 . This groove 19 is intended to receive the stop ring 20, which is 3 is shown.

3 shows the protective device according to the invention for an additional spring device 10 in four states. 3a shows the components of the additional spring device 10 with protective device with its individual elements additional spring receptacle 12, additional spring 14, protective tube (bellows) 18, base 16 and the stop ring 20 arranged on the base 16 in the groove there (not marked). This protrudes slightly in its circumference out of the base 16, so that it can form a stop for the bellows 18 during compression.

In 3b The additional spring device 10 is shown with the protective device in a starting position. The protective tube 18 encloses the auxiliary spring 14. There is a space between the bellows 18 and the base 16 with the stop ring 20, since there is no deflection. This is done in 3c . The deflection creates contact between the bellows 18 and the stop ring 20 on the base 16 so that the bellows 18 can be compressed while the stop ring seals the contact area between the bellows 18 and the stop ring 20 . For this purpose, the last fold of the bellows 18 is cut in such a way that it ends at its widest point and thus has a funnel-shaped end that guides the bellows 18 or the base 16 down to the stop ring 20 and ensures adequate sealing there.

The stop ring 20 is made of a polyoxymethylene (POM) and with at least one air outlet 24, in the exemplary embodiment of FIG 3 formed with a plurality of air outlets 24. These are selected in terms of their size, number, shape and orientation in such a way that in the event of a sudden deflection, an air cushion is initially formed in the additional spring device 10, which limits the spring deflection and thus also the load application from the deflection, but then the air through the air outlets 24 can emerge in a predetermined manner (arrows 22). The air outlets 24 are selected in particular in such a way that the bellows 18 is prevented from bursting during compression.

the 4 and 5 show exemplary configurations of stop rings 20. In 4 a stop ring 20 is shown in which the air outlets 24 are formed circumferentially around the stop ring 20 in the same size and orientation. So that the stop ring 20 can be placed on the base 16 and engaged with the groove 19 , it is designed with an opening 26 which enables the stop ring 20 to be pushed onto the base 16 .

In an alternative embodiment, the stop ring is 20 in 5 shown. The stop ring 20 is formed there with an outer ring 28 and lamellae 30 . The contour 32 of the base 16 in the area of the groove 19 is entered in sections for better understanding. It can be seen that the slats 30 are each arranged in groups of three, each of which forms air outlets 24 of different sizes with the outer ring 20 and the base 16 . This is shown in the perspective view of 5b once again clarified.

The protective device according to the invention is preferably provided on all axle structures of a vehicle.

Reference List

10

additional spring device

12

additional spring mount

14

Auxiliary spring, bump stop

16

document

18

protective tube

19

groove

20

stop ring

22

outflowing air

24

air outlet

26

opening

28

outer ring

30

lamella

32

contour underlay

50

coil spring

52

handlebars

Claims (10)

Protective device for an additional spring device (10) on an axle construction of a vehicle, the additional spring device (10) being formed with an additional spring mount (12), an additional spring (14), a base (16) and an at least partially foldable protective tube (18), wherein the auxiliary spring mount (12) holds the auxiliary spring (14), the at least partially foldable protective tube (18) is arranged on the auxiliary spring mount (12) in such a way that it at least partially encloses the auxiliary spring (14), and the base (16) relative to the The additional spring (14) is arranged in such a way that when the axle construction deflects, the additional spring (14) hits the base (16) and is compressed and/or the additional spring (14) is connected to the base (16) and the deflection of the Axle construction is compressed, characterized in that a groove (19) is formed at least in sections along the circumference of the base (16) and a stop ring (20) on the base (16) is arranged such that it engages with the groove (19) and forms a stop for the at least partially foldable protective tube (18), and the stop ring (20) has and/or forms at least one air outlet (24) in order to to set flow conditions in a targeted manner during a spring action in the axle construction. protective device claim 1 , characterized in that the additional spring (14) is a stop buffer, in particular a stop buffer formed with a foamed polyurethane. protective device claim 1 or 2 , characterized in that the stop ring (20) is formed with an outer ring (28) and lamellae (30), the lamellae (30) spacing the outer ring (28) from the base (16) and through the outer ring (28), the slats (30) and the base (16) at least one air outlet (24) is formed. Protective device according to one of the preceding claims, characterized in that the flow conditions can be set by the number, shape, size, position, alignment and/or variance of the at least one air outlet (24). protective device claim 4 , characterized in that the number, the shape, the size, the position, the orientation and/or the variance of the at least one air outlet (24) are selected in order to prevent the protective tube (18) from bursting. Protective device according to one of the preceding claims, characterized in that the at least partially foldable protective tube (18) is designed with a funnel-like opening at its end directed towards the base (16). Protection device according to one of the preceding claims, characterized in that the at least one air outlet (24) is formed with a dirt protection against penetrating dirt, in particular with a valve, a flap, a skin, a cover, a wing, a brush, a brush and/or a felt filling. Protective device according to one of the preceding claims, characterized in that the stop ring (20) is formed from a plastic, in particular a polyoxymethylene or a polyamide. Protective device according to one of the preceding claims, characterized in that the stop ring (20) is produced by means of 3D printing or an injection molding process. Vehicle in which at least one axle device has a protective device according to one of the preceding claims.

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