AT521482B1 - Leaf spring with spacer - Google Patents

Abstract

A leaf spring (1), in particular trapezoidal spring, parabolic spring or trailing arm, for use in a wheel suspension of a vehicle has at least one spring leaf (2) with an upper side, a lower side (11), two end sections (4), one between the end sections (4 ) extending central section (5) and a preferably centrally located in the central section (5) arranged clamping area (6), and at least one on the bottom (11) or top in the clamping area (6) of the spring leaf (2) arranged spacers (3). At least one anti-rotation device (13) is arranged between the spring leaf (2) and the spacer (3). The anti-rotation device (13) has a first adhesive layer (14), a further adhesive layer (15) and a compressible layer (16) arranged between the adhesive layers (14, 15).

Description

The invention relates to a leaf spring, in particular trapezoidal spring, parabolic spring or trailing arm, for use in a wheel suspension of a vehicle, the leaf spring having at least one spring leaf with an upper side, an underside, two end sections, a middle section extending between the end sections and a preferably centrally located in the central section clamping area, and has at least one spacer arranged on the underside or top in the clamping area of the spring leaf, and wherein at least one rotation lock is arranged between the spring leaf and the spacer.

In order to enlarge the distance between the resilient part of the leaf spring, which consists of a spring leaf or several interconnected spring leaves, and the axis arranged below or above it in conventional wheel suspensions, at least one spacer between the spring leaf / the spring leaves of the leaf spring and arranged a bracket or guide of the axis.

The spacer is preferably connected to the resilient part of the leaf spring, for example via a bolt, and has a small length compared to the total length of the leaf spring. It is essentially the same width as the spring leaves or also narrower, so that it does not protrude laterally over them and when mounting the leaf spring one or more U-brackets can be guided over the spring leaves connected to one another and the spacer.

Before installing the leaf spring having the spacer in a wheel suspension, it can happen, for example, during transport shocks or improper storage that the spacer is rotated in comparison to the rest of the leaf spring, so that portions of the spacer protrude laterally beyond the spring leaves. One solution to prevent this is to use an anti-twist device made from bent sheet metal.

Such an anti-rotation device is, for example, Z-shaped and has a central region and two side regions adjoining it at right angles and extending in opposite directions. The central region of the anti-rotation device is arranged between the resilient part of the leaf spring and the spacer or between two spring leaves of the leaf spring. One of the side areas rests on at least one spring leaf and the other side area on the spacer - and, if appropriate, in front of it on further spring leaves, so that a positive locking against rotation is formed.

It is also conceivable that such an anti-rotation device is U-shaped and has a central region and two side regions adjoining it at right angles, which run in the same direction. The central area of this anti-rotation device is arranged between two spring leaves of the leaf spring. The side areas encompass the remaining leaf spring together with the spacer and lie laterally on it, so that a positive locking against rotation is formed.

The production of leaf springs with such anti-rotation is however - despite the simple design of the anti-rotation made of bent sheet metal - complex and expensive. This is due to the fact that the anti-rotation locks described above have to be manufactured with a particularly precise fit, since even slight deviations from tolerance specifications or small material defects can result in the anti-rotation locks being extremely difficult or even impossible to install when assembling the leaf spring, or in that the anti-rotation locks damaged or destroyed when assembling or transporting the leaf springs. In addition, leaf springs with such anti-rotation devices have a higher weight, since the anti-rotation devices are usually made of metal.

The invention is based on the object to provide a leaf spring of the type mentioned, which does not have the disadvantages of the prior art.

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AT 521 482 B1 2020-02-15 Austrian patent office

In particular, in the leaf spring according to the invention, one is arranged on a spring leaf

Spacers are secured against twisting by at least one anti-twist device, which is particularly simple and easy to manufacture and install and also weighs less than anti-twist devices made of sheet metal.

The object underlying the invention is achieved according to the invention with a leaf spring which has the features of claim 1.

[0010] Preferred and advantageous embodiments of the invention are the subject of the dependent claims.

According to the invention it is provided that the anti-rotation device has a first adhesive layer, a further adhesive layer and a compressible layer arranged between the adhesive layers.

The surfaces of the spring leaf and the spacer, which have surface bumps due to the manufacture or processing, can not be arranged plane-parallel to each other due to these bumps, and are therefore not flat, but only in areas or even points at each other. In particular, when assembling the leaf spring, the surfaces are raw from rolling and therefore have a relatively large surface unevenness or relatively large unevenness. A single adhesive layer arranged between them can therefore only connect the two surfaces with one another in areas and not across the board.

[0013] In the anti-rotation device according to the invention, surface irregularities can be compensated for particularly effectively by the more or less compressed compressible layer, so that a substantially area-wide connection between the surfaces can be formed using the two adhesive layers.

Furthermore, the anti-rotation device according to the invention is particularly light compared to conventional anti-rotation devices, which are made of sheet metal, for example. This can reduce the weight of the leaf spring.

Another advantage is that the anti-rotation device according to the invention is arranged entirely in the clamping area. For the purposes of the invention, that area of the leaf spring is referred to as the clamping area in which the leaf spring is pressed onto an axle or an axle pin by means of axle connection devices, such as two U-bolts or a pin guided through the spring blades. In contrast to conventional anti-rotation devices, no component of the anti-rotation device that increases the width of the leaf spring, at least in some areas, projects laterally beyond the spring leaf or the spacer.

The leaf spring according to the invention can be a multi-leaf spring or a single leaf spring, optionally with a base leaf. Within the scope of the invention, the top of a spring leaf is considered to be that side of the spring leaf which is essentially loaded in tension during use, and the bottom is considered to be the side which is essentially loaded under pressure in use.

In the field of application of the invention, a spacer essentially has the main task of increasing the distance between the resilient part of the leaf spring, consisting of at least one spring leaf, and an axis arranged below or above it. The spacer (s) installed in the leaf spring according to the invention therefore have a certain thickness, for example of at least 5 mm. A much thinner intermediate plate used in conventional leaf springs is not a spacer in the sense of the invention.

In the context of the invention, however, components of the leaf spring are also regarded as spacers, which primarily serve a different purpose than increasing the distance between the resilient part of the leaf spring and the axis, as long as they are below or above a spring leaf or another spacer are arranged and have a certain thickness, for example of at least 5 mm. Such a component is for example

2.7

AT 521 482 B1 2020-02-15 Austrian Patent Office shows a roll layer consisting of a metal strip at one end

Connecting element, in particular an eye, is formed for connecting to a shock absorber.

[0019] A leaf spring according to the invention can have more than one spacer, the two or more spacers being arranged one above the other or one above the other. In any case, in the case of more than one spacer, an anti-rotation device according to the invention is provided at least between the spacer arranged on the resilient part of the leaf spring, that is to say on a spring leaf, and the associated spring leaf.

Preferred embodiments are those in which the spring leaf is connected to the spacer via a connecting element, in particular a screw or a bolt, preferably a heart bolt. Such a connecting element is guided, for example, through a through hole in the clamping area of the spring leaf and through a further through hole in the spacer and presses the spacer towards the spring plate. In the case of a multi-leaf spring, each individual spring leaf preferably has a through hole through which the connecting element is guided. The connecting element presses together the components of the leaf spring.

It is also possible within the scope of the invention that the spring leaf or the spring leaves and the spacer (s) are enclosed and pressed together by U-shaped bolts.

In a preferred embodiment, the connecting element is guided through a further through hole in the anti-rotation device. In this embodiment, the anti-rotation device preferably covers the entire clamping area, so that a particularly large-area connection is formed between the spring leaf and the spacer.

In another preferred embodiment, at least one anti-rotation device is arranged between the spring leaf and the spacer on both sides of the connecting element. This simplifies the manufacture and the attachment of the anti-rotation device, since only suitable, for example rectangular, pieces without recesses have to be provided and applied between the spacer and the spring leaf.

In the context of the invention, it is preferred if the compressible layer is a porous layer. The layer is preferably formed from an elastic plastic, in particular a solidified foam, preferably a polyethylene foam. Such a layer can be compressed particularly strongly, so that large unevenness can be compensated for by the anti-twist device even with a small thickness of the anti-twist device.

In particular, an embodiment is preferred within the scope of the invention in which an elastic layer, in particular a film, preferably made of plastic or metal, is arranged between the first adhesive layer and the compressible layer and / or between the compressible layer and the further adhesive layer , Such a layer prevents the adhesive of the adhesive layers from penetrating into the compressible layer if it consists, for example, of a porous material such as foam.

However, it is also possible within the scope of the invention that the compressible layer is a non-porous and essentially compact layer, for example made of an elastic plastic, such as rubber or silicone. An anti-rotation device produced with such a layer is compressible by pushing the layer into the width, but additionally has the advantage that the adhesive layers can be applied directly to the compressible layer without adhesive being able to penetrate the compressible layer.

Embodiments are preferred which have anti-rotation devices which, in the uncompressed state, between 0.3 mm and 8.0 mm, in particular between 0.4 mm and 5.0 mm, preferably between 0.5 mm and 2.0 mm, is thick. Such anti-rotation devices are thick enough to be able to evenly fill a gap between the surface of the spring leaf and the spacer arranged thereon even in the case of gross deviations from specified manufacturing tolerances. The state of the torsion 3/7 is called the uncompressed state

AT 521 482 B1 2020-02-15 Austrian patent office understood by not yet being between the surface of the spring leaf and the

Surface of the spacer is pressed in, i.e. before the leaf spring according to the invention is completely assembled.

In a preferred embodiment, the spacer is essentially as wide as the spring leaf arranged thereon. In particular, the spacer is essentially as long as the clamping area or shorter than this. This saves as much material and weight as possible with full functionality.

However, embodiments are also conceivable in which the spacer, seen in the longitudinal extension of the leaf spring, projects beyond the clamping area. In such embodiments, the spacer can perform other functions - in addition to increasing the distance between the resilient part of the leaf spring and the axis.

It is possible within the scope of the invention that the leaf spring in one or both end sections has a means for connecting the leaf spring to a chassis of a vehicle. Such a means for connecting, for example an eye, is in particular formed directly on the spring leaf or one of the spring leaves, whereby the manufacture of the leaf spring is simplified. The means for connecting is preferably a rolled eye, which is formed by rolling in one of the end regions, it being possible for a gap to be formed between the end face of the rolled end region and the top or bottom of the spring leaf.

In a preferred embodiment, at least the spring leaf (s) of the leaf spring is / are made of steel, in particular spring steel. The spacer (s) is / are also preferably made of steel, in particular spring steel. A leaf spring according to the invention made of steel has less weight due to the anti-rotation lock according to the invention than a leaf spring made of steel with a conventional anti-rotation lock, so that material and costs can be saved.

Embodiments are also conceivable in which the spacer (s) is made of light metal, in particular aluminum, or an alloy. Furthermore, the spacer (s) can be cast, sintered, forged or manufactured by a machining process.

In the context of the invention, an embodiment is also possible in which a part or more parts of the leaf spring, in particular the spring leaf / spring leaves and / or the spacer (s), made of plastic, in particular made of fiber-reinforced plastic, preferably made of glass-fiber reinforced plastic ( GFK), is / are.

A vehicle wheel suspension according to the invention has at least one leaf spring according to the invention. Such a wheel suspension can be assembled particularly quickly and effectively, since the risk that the spacer is rotated relative to the rest of the leaf spring is eliminated, and the leaf spring installed therein therefore has no components projecting beyond the width of the spring.

Further details, features and advantages of the invention will become apparent from the following description with reference to the accompanying drawing, in which preferred embodiments are shown. It shows:

Fig. 1 is an isometric view of a leaf spring according to the invention with a detail of the leaf spring in a sectional view, Fig. 2 shows an embodiment of an anti-rotation device applied to a spacer, and Fig. 3 shows another embodiment of the on the spacer applied anti-rotation device.

1 shows a leaf spring 1 according to the invention with two spring leaves 2 and a spacer 3.

[0040] Each spring leaf 2 has two end regions 4, a central portion 4/7 arranged between them

AT 521 482 B1 2020-02-15 Austrian patent office empire 5 and a clamping area 6 arranged centrally in the middle area 5. The clamping area 6 is the area in which the leaf spring 1 is pressed onto an axle or an axle pin by axle connection devices, not shown, such as two U-bolts, for example. The spacer 3 is essentially as long as the clamping area 6.

The spring leaves 2 and the spacer 3 are connected to each other and pressed together via a connecting element 7, which is guided through through holes 8 in the clamping areas 6 of the spring leaves 2 and through a further through hole 9 in the spacer 3.

Between an underside 11 of the one spring leaf 2 and an upper side 12 of the spacer 3, at least one anti-twist device 13 - not visible in FIG. 1 - is arranged.

The enlarged detail of FIG. 1 shows a section through the spacer 3, the anti-rotation device 13 and the spring leaf 2 arranged on the spacer 3 in the region of the underside 11 of the spring leaf 2 and the upper side 12 of the spacer 3.

The anti-rotation device 13 has - as shown - at least a first adhesive layer 14 which is glued to the underside 11 of the spring leaf 2, a further adhesive layer 15 which is glued to the top 12 of the spacer 3, and one between the adhesive layers 14 15 arranged compressible layer 16.

2 and 3 show two possible embodiments of how the spacer 3 can be secured against rotation on the spring leaf 2. For better illustration, the spring leaves 2 and the connecting element 7 are not shown in FIGS. 2 and 3.

In the embodiment shown in FIG. 2, a single anti-rotation device 13, which extends essentially over an entire surface 12 of the spacer 3, is arranged between the spacer 3 and the clamping area 6 of the spring leaf 2, not shown.

The anti-rotation device 13 in this embodiment has a shape and size to the through holes 8 of the leaf springs 2 and to the further through hole 9 of the spacer 3 matching, further through hole 17 through which the connecting element 7 is guided.

In the embodiment shown in FIG. 3, two anti-rotation devices 13, each applied to the side of the further through hole 9 of the spacer 3, are arranged between the spacer 3 and the clamping area 6 of the spring leaf 2, not shown.

In the illustrated embodiment, the two anti-rotation devices 13 extend essentially over the entire width of the spacer 3 or the clamping area 6 of the leaf spring 2, not shown.

Embodiments are also conceivable in which more than two anti-rotation devices 13 are provided between the spacer 3 and the spring leaf 2. These anti-rotation devices 13 can be designed with or without further through holes 17 and can be arranged as desired in the clamping area 6 between the underside 11 of the spring leaf 2 and the upper side 12 of the spacer 3, for example in strips or in parallel in the longitudinal or transverse extension of the leaf spring, in a punctiform or patterned manner.

Claims (10)

1. leaf spring (1), in particular trapezoidal spring, parabolic spring or trailing arm, for use in a wheel suspension of a vehicle, the leaf spring (1) having at least one spring leaf (2) with an upper side, a lower side (11), two end sections (4), a central section (5) extending between the end sections (4) and a clamping area (6) preferably arranged centrally in the central section (5), and at least one spacer arranged on the underside (11) or upper side in the clamping area (6) of the spring leaf (2) (3), and wherein at least one anti-rotation device (13) is arranged between the spring leaf (2) and the spacer (3), characterized in that the anti-rotation device (13) has a first adhesive layer (14), a further adhesive layer (15) and has a compressible layer (16) arranged between the adhesive layers (14, 15). 2. Leaf spring according to claim 1, characterized in that an anti-rotation device (13), two anti-rotation devices (13) or more anti-rotation devices (13) are / are arranged at least over part of the area between the spring sheet (2) and the spacer (3). 3. Leaf spring according to claim 1 or 2, characterized in that the spring leaf (2) with the spacer (3) via a connecting element (7), in particular a screw or a bolt, is connected, wherein the connecting element (7) through a through hole (8) in the clamping area (6) of the spring leaf (2) and through a further through hole (9) in the spacer (3) and presses the spacer (3) towards the spring leaf (2). 4. Leaf spring according to claim 3, characterized in that the connecting element (7) is guided through a further through hole (17) of the anti-rotation device (13). 5. Leaf spring according to claim 3 or 4, characterized in that between the spring leaf (2) and the spacer (3) on both sides of the connecting element (7) in each case at least one anti-rotation device (13) is arranged. 6. Leaf spring according to one of claims 1 to 5, characterized in that the compressible layer (16) is a porous layer, preferably an elastic foam layer. 7. leaf spring according to one of claims 1 to 6, characterized in that between the first adhesive layer (14) and the compressible layer (16) and / or between the compressible layer (16) and the further adhesive layer (15) an elastic layer, in particular a film, preferably made of plastic or metal, is arranged. 8. Leaf spring according to one of claims 1 to 7, characterized in that the anti-rotation device (13) in the uncompressed state between 0.3 mm and 8.0 mm, in particular between 0.4 mm and 5.0 mm, preferably between 0, 5 mm and 2.0 mm, is thick. 9. leaf spring according to one of claims 1 to 8, characterized in that the spacer (3) is substantially as wide as the spring leaf (2) arranged thereon and / or that the spacer (3) is substantially as long as the clamping region ( 6) or shorter than the clamping area (6) or longer than the clamping area (6). 10. Wheel suspension of a vehicle, the wheel suspension having at least one leaf spring (1) according to one of claims 1 to 9.