DE102018218456A1 - Method for connecting an air bellows to an outer element of an air spring and air spring - Google Patents

Abstract

A method for connecting an air bellows to an outer element of an air spring and an air spring are described. In the method, a clamping ring is first folded into a star and inserted into the air bellows inserted in the outer element in order to position the components relative to one another. The clamping ring star is then folded back into its round shape until it presses against the air bellows in the original ring shape and thus clamps the air bellows with the outer element. In this way, a corresponding connection with particularly high strength can be produced with a low use of materials.

Description

The present invention relates to a method for connecting an air bellows to an outer element of an air spring by clamping the air spring bellows to the outer element with a clamping ring braced against the air bellows and the outer element.

For example, the use of external air springs in connection with cardanic folds requires the outer guide to be attached to the air bellows. This connection must have a high strength. In order to provide this high strength statically and dynamically, the bellows is clamped to the outer guide with a clamping ring that is clamped against the outer guide. This connection is normally made in such a way that the outer guide (analogous to a cover / piston clamp) is deformed radially inwards with a clamping machine and is pressed against a clamping ring. The remaining tension of the bellows located between the clamping ring and the deformed outer guide when springing back brings the strength of the clamping connection. To increase the strength, the surface of the inside of the outer guide is provided with grooves and / or teeth in the area of the clamping. Furthermore, when the outer guide is clamped, care is taken to ensure that it wraps around it radially inward above and below the clamping ring, thus creating an at least partially established positive fit.

A clamping of the clamping ring from the inside to the outside usually does not take place because the machine technology required for this deviates from that of a piston or cover clamping (clamping movement from the outside radially inwards) and, moreover, there would be no positive locking. Other connection options, such as gluing, have corresponding disadvantages compared to a clamp connection in terms of performance and / or robustness.

The present invention has for its object to provide a method of this type with which a corresponding connection with particularly high strength can be produced with little material.

This object is achieved according to the invention by a method of the type specified, in which the clamping ring is first folded into a star and inserted into the air bellows inserted in the outer element in order to position the components relative to one another, and in which the clamping ring star is then folded back into its round shape until it presses against the air bellows in the original ring shape and thus jams the air bellows with the outer element.

The clamping connection according to the invention is produced by first folding the clamping ring into a star and then folding it back into the ring. The significant collapse of the inner ring into the star shape creates a radial reduction in the circumference. In this form, the clamping ring can be inserted into the bellows inserted into the outer element. As a result, the components are positioned in relation to each other in the later ZSB arrangement.

When the clamping ring star is folded back into its round shape, the radius of its periphery increases again until it presses against the bellows and the outer element in the original ring shape and thus clamps the bellows against the outer element.

In a further development of the invention, a clamping ring is used which has cross-sectional reductions distributed at intervals over its circumference. Here, in particular, a clamping ring with cross-sectional reductions is used, which are designed as notches from the inside.

The fold-in and fold-out movement of the clamping ring is controlled by these cross-sectional reductions. The locations of the cross-sectional reductions or notches act like plastic joints between the non-notched clamping ring sections, which in turn act like rigid connecting elements between the joints. When folded into the star shape, the clamping ring behaves like a mechanism connected by joints.

The realization of the reduction in cross-section by means of notches from the inside has two other positive effects in addition to the provision of the plastic joints. On the one hand, the notch insertion from the inside allows a gentle deformation of the clamping ring to an outward pointed star. On the other hand, the notch from the inside causes the outside of the clamping ring to remain smooth when the clamping ring is deformed, which does not damage the bellows when pressed against the air bellows.

According to the invention, an inexpensive alternative for clamping an outer element onto the air bellows of an air spring is thus made available. This connection can be made possible without plastic deformation of the outer element, and other material classes (without pronounced plastic flow properties, for example plastics) can also be used for the outer element. In any case, a connection with a particularly high strength is created with little use of material. The production the connection is achieved through an inexpensive process.

In a further embodiment of the invention, a clamping ring with cross-sectional reductions that are trough-shaped is used.

A clamping ring is also preferably used, which is contoured on its radial outside.

The method according to the invention involves the production of a connection between an air bellows and an outer element of an air spring. For example, an outer guide of an air spring or a corresponding support ring can be used as the outer element. In a first method variant, the air bellows is therefore clamped with an outer guide of an air spring. In a second variant, the air bellows is clamped in the cardanic fold of an air spring with a support ring. This does not exclude that the method according to the invention relates to other types of jamming, for example jamming of the air bellows with the cover or the piston of an air spring strut.

In the method according to the invention, a clamping ring is preferably used which has cross-sectional reductions at the kink points, in which the center of gravity in the kink point is shifted radially outward relative to the center of gravity in the non-kinked areas.

This method variant is used in particular when the clamping ring is deformed by a large number of kinks, and relates to a further type of formation of the plastic joints of the clamping ring. In order to ensure that the clamping ring folded back into the ring shape remains in the clamped shape even when the stability is reduced due to a large number of kink points, the clamping ring cross section at the later kink points is reduced from the inside, for example by sawing notches or embossing notches, so that the center of gravity in the kinking point is opposite that Center of gravity in the non-kinked areas shifted radially outwards.

This type of change in the center of gravity leads, in connection with the cutting forces in the clamping ring folded back into a ring shape, to a moment which further increases the stability of the round shape in a system against the structure of bellows and outer element.

The cutting forces are the same on both cutting surfaces (non-notched area and notched area), but the force application point is more radially inward in the non-notched area than in the notched area. This radial displacement leads to an offset moment which tries to turn the clamping ring counterclockwise and thus to press against the structure of the bellows and outer element.

Instead of the notches in an otherwise solid clamping ring, a ring can also be used, which is stamped in such a way that where the solid ring has the full cross section in the various possible divisions, a trough or a rim pressed inwards is now embossed , whereas no embossing is made in the areas notched in the solid ring. The operation of such a ring corresponds to that of a solid clamping ring with notches. The following advantages result: less use of material, greater shift of the center of gravity of the cross section in the embossed area compared to the non-embossed joint area radially inwards.

In yet another method variant, an outer element and / or a clamping ring is used which has a circumferential trough. Such a trough on the outer element or clamping ring leads to a complete or partially effective form fit in the axial direction in addition to the radial compression. If a clamping ring with a circumferential trough is used, the outer element preferably has an outwardly oriented curvature and vice versa.

The method according to the invention offers a number of advantages. The clamping ring no longer has to bear the forces required to form the outer element from the outside during the clamping process and can therefore be produced from less valuable material and with a smaller cross-sectional area. In principle, it becomes possible to produce the clamp connection without deformation of the outer element. This means that materials can be used for the outer element that have no or no pronounced plastic deformation capacity, for example plastics. The deadlock is shifted radially from the outside to a deadlock. This creates greater freedom of movement in relation to moving parts inside the air spring, which in turn offers many advantages.

The present invention further relates to an air spring with an air bellows and an outer element, in which the air bellows is connected to the outer element by a method of the type described above with the aid of a clamping ring. This is the outer element preferably around an outer guide or a support ring in a cardanic fold of an air spring.

• 1 einen Teilvertikalschnitt durch eine Luftfeder;
• 2 eine Draufsicht auf einen Klemmring innen im zusammengefalteten Zustand und außen in an einer Außenführung der Luftfeder angepressten Zustand;
• 3 einen Teilschnitt durch einen Klemmring mit Darstellung einer Querschnittsverkleinerung;
• 4 vier verschiedene Phasen beim Zusammenfalten des Klemmringes;
• 5 eine Sternzacke des gefalteten Klemmringes;
• 6 einen Teilvertikalschnitt durch eine Luftfeder mit Anordnung eines Stützringes und eines Klemmringes bei einer Kardanikfalte;
• 7 einen Abschnitt eines Klemmringes mit Darstellung der Flächenschwerpunkte;
• 8 eine weitere Ausführungsform einer Klemmringbefestigung; und
• 9 noch eine weitere Ausführungsform einer Klemmringbefestigung.

The invention is explained in detail below using exemplary embodiments in conjunction with the drawing. Show it:

• 1 a partial vertical section through an air spring;
• 2nd a plan view of a clamping ring inside in the folded state and outside in a pressed state on an outer guide of the air spring;
• 3rd a partial section through a clamping ring showing a reduction in cross section;
• 4th four different phases when folding the clamping ring;
• 5 a star point of the folded clamping ring;
• 6 a partial vertical section through an air spring with arrangement of a support ring and a clamping ring in a cardanic fold;
• 7 a portion of a clamping ring showing the centroids;
• 8th a further embodiment of a clamping ring attachment; and
• 9 yet another embodiment of a clamping ring attachment.

1 shows a partial vertical section through an air spring 1 . The design of such an air spring is generally known and will not be described in detail here. Only those components that are essential to the invention are discussed here.

Air spring 1 has an outside guide 2nd with an air bag 3rd connected is. The connection is made via a clamping ring 4th .

The clamping ring connection between the outer guide 2nd and the air bag 3rd is made by the clamping ring 4th first folded into a star and then folded back into a ring. The clamping ring folded into a star 4th is in 2nd shown inside. In this form, the clamping ring 4th in the in the outside guide 2nd air bellows inserted 3rd be put in.

The folding and unfolding movement of the clamping ring 4th who in 2nd is shown outside in its end position, by appropriate cross-sectional reductions 5 on the clamping ring 4th controlled, which is on the inside of the clamping ring 4th intended notches. 3rd shows an enlarged view of such a notch.

The folding process of the clamping ring 4th is in 4th presented in four phases. When folding the clamping ring 4th there is initially an increase in the radius (state " 0 "To state" 1 ") before the circumference is then reduced (state" 1 "to states" 2nd " and the following). When unfolding back to the round shape (state " 3rd "About state" 2nd "," 1 "To state" 0 “) It happens the other way round. It is found that between the circular initial shape (state " 0 ") And a star shape with the same radius (state" 2nd ") A shape with a maximum radius (state" 1 ") gives. This state " 1 “With the maximum circumference leads to the clamping ring star being braced against the air bellows 3rd with a higher energy state than the states shown " 0 " and " 2nd ". It acts like a dead center, which with active effort when passing through the state " 1 “Must be overcome if the radial expansion possibility of the clamping ring is hindered, for example, by the structure of the bellows and the outer guide. So when folding back the clamping ring from the star shape " 3rd "On the round shape" 0 "The star is pressed from the inside, then the star must be pressed against the bellows and the outer guide over the dead center at" 1 “Be actively pushed through. The force required to press the ring on from the inside increases until dead center. Is the dead center " 1 “Passed through, then because of the reduction in the tension of the star against the structure of the bellows and the outer guide, it takes for further deformation to the round shape“ 0 “Required force from or the ring is pressed round by the braced package of bellows and outer guide, without this having to be done by an active force.

There is the clamping ring 4th again in a shape close to the original round shape " 0 “Then the bracing of the ring against the package of bellows and outer guide keeps the ring stable in its round shape, because it is the lowest energy state.

The even number of cross-sectional reductions 5 or notches in the clamping ring 4th can be increased from a minimum of eight to ten to twelve etc. A number of six prevents a radial reduction in the radius and thus the mechanism described above.

The greater the even number of cross-sectional reductions 5 or notches, the greater the radial tension path that can be represented when the clamping ring is pressed round again 4th . At the same time, the difference in the circumference between the states " 0 " and " 1 "From. This decrease goes hand in hand with a lower (disadvantageous) stability of the round shape against the structure made of bellows 3rd and outside guidance 2nd clamped clamping ring 4th and with a gentler (advantageous) deformation of this structure when passing through the dead center at “ 1 ". Numbers of cross-sectional reductions 5 or notches of 10, 12 and 14 are therefore advantageous when optimizing the stability and stress of the parts to be pressed, bellows and outer element.

5 shows a jag of the clamping ring 4th with folding in one place of a cross-sectional reduction 5 .

The internal clamping described above can also be applied to other connections, such as the clamping between the support ring 7 and the clamping ring 6 in the cardanic fold of an air spring. Such a case is in 6 shown.

7 shows a section of a clamping ring 4th with cross-sectional reduction. Here, the cross-section of the clamping ring is reduced at a later kink by an embossing notch from the inside so that the center of gravity is 11 in the kink opposite the center of area 10th shifted radially outwards in the non-kinked areas. In 7 is the radial distance of the centroid 10th the notched cross-sectional area on the left and the radial section of the centroid 11 the notched section surface shown on the right. This change in the center of gravity leads in connection with the cutting forces in the clamping ring folded back into the ring shape 4th at a moment that further strengthens the stability of the round shape in a system against the structure of bellows and outer element.

The 8th and 9 show embodiments in which the outer element 2nd and 7 or the clamping ring 6 are designed in such a way that a circumferential trough is introduced or provided there, which then leads to a complete or partially effective form fit in the axial direction in addition to the radial pressing.

Reference list

1

Air spring

2nd

External guidance

3rd

Air bag

4th

Clamping ring

5

Cross-sectional reduction

6

Clamping ring

7

Support ring

10th

Center of gravity

11

Center of gravity

Claims (11)

Method for connecting an air bellows (3) to an outer element (2) of an air spring (1) by clamping the air spring bellows (3) to the outer element (2) with a clamping ring (4) braced against the air bellows (3) and the outer element (2) , 6), in which the clamping ring (4, 6) is first folded into a star and inserted into the air bellows (3) inserted in the outer element (2) in order to position the components relative to one another, and in which the clamping ring star is then in its Round shape is folded back until it presses in the original ring shape against the air bellows (3) and thus jams the air bellows (3) with the outer element. Procedure according to Claim 1 , characterized in that a clamping ring (4, 6) is used which has cross-sectional reductions (5) distributed at intervals over its circumference. Procedure according to Claim 2 , characterized in that a clamping ring (4, 6) with cross-sectional reductions (5) is used, which are designed as notches from the inside. Procedure according to Claim 2 , characterized in that a clamping ring (4, 6) with cross-sectional reductions (5) is used, which are trough-shaped. Procedure according to one of the Claims 2 to 4th , characterized in that a clamping ring (4, 6) is used which has cross-sectional reductions (5) at the kinks, in which the center of gravity (11) in the kink is displaced radially outwards relative to the center of gravity (10) in the non-kinked areas . Method according to one of the preceding claims, characterized in that a clamping ring (4) is used which is contoured on its radial outside. Method according to one of the preceding claims, characterized in that the air bellows (3) is clamped with an outer guide (2) of an air spring (1). Procedure according to one of the Claims 1 to 6 , characterized in that the air bellows (3) is clamped with a support ring (7) in the cardanic fold of an air spring (1). Procedure according to one of the Claims 2 to 8th , characterized in that a clamping ring (4) is used, which has embossed depressions in its areas outside the cross-sectional reductions (5). Method according to one of the preceding claims, characterized in that an outer element (2) and / or a clamping ring (6) is used which has a circumferential trough. Air spring with an air bellows (3) and an outer element (2), characterized in that the air bellows (3) by a method according to one of the Claims 1 to 10th is connected to the outer element (2) by means of a clamping ring (4, 6).

Images