Flexible cable section

Abstract

Bellows (1, 1') with at least one annularly corrugated section (2, 2a), in which the bellows (1, 1') has a first corrugation with corrugation crests (10) and corrugation troughs (9) oriented in the circumferential direction, and with at least one terminal connecting section (3, 3'), in which the bellows (1, 1') has at least in some regions a second corrugation with corrugation crests (4) and corrugation troughs (5), which second corrugation is different from the first corrugation, in which in a region of the second corrugation an effective inner radius (r eff1 ) of the connecting section (3, 3') of an effective inner radius (r eff2 ) of the bellows (1, 1') in a region of the first corrugation is different, wherein the effective inner radius (r eff2 ) of the bellows (1, 1') in the region of the first corrugation is defined as a shortest distance between a longitudinal axis (L) of the bellows (1, 1') and a corrugation trough (9) of the annularly corrugated section (2, 2a), and wherein the effective inner radius (r eff1) of the connecting section (3, 3') is defined as the distance between the longitudinal axis and a point of the connecting section (3, 3') in the region of the second corrugation, which point is closest to the longitudinal axis (L), characterized in that the corrugation peaks (4) and corrugation troughs (5) in the region of the second corrugation are oriented in the circumferential direction.

Description

The present invention relates to a bellows according to the preamble of claim 1. such a bellows is suitable in particular for use in an exhaust system of a motor vehicle and comprises at least one ring-corrugated section, in which the bellows has a first corrugation with circumferentially oriented corrugation peaks and corrugation valleys, and a terminal connection section, in which the bellows has at least in regions a second corrugation with corrugation peaks and corrugation valleys, which second corrugation is different from the first corrugation, in which in a region of the second corrugation an effective inner radius of the connection section is different from an effective inner radius of the bellows in a region of the first corrugation.The effective inner radius of the bellows in the region of the first corrugation is defined as a shortest distance between a longitudinal axis of the bellows and a corrugation trough of the annularly corrugated section, and the effective inner radius of the connection section is defined as a distance between the longitudinal axis and a point of the connection section in the region of the second corrugation, which point is closest to the longitudinal axis.The present invention also relates to a line part according to the preamble of claim 8, such a line part being provided in particular for use in an exhaust system of a motor vehicle and comprising at least one bellows according to the invention, an internal component and an annular fixing element for connecting the bellows and internal component.The invention further relates to a method for producing a bellows according to the preamble of claim 13 and to an exhaust gas line having a line part according to the preamble of claim 18.Bellows or line parts of the aforementioned type are installed in exhaust lines of an internal combustion engine, in particular in the exhaust line of a drive engine of a motor vehicle, in order to decouple vibrations which the pulsating exhaust gas flow of the internal combustion engine, or else body vibrations of the engine itself, from the exhaust system, since such vibrations can cause undesired noises. In addition, vibrations can significantly impair the service life of the exhaust system. In addition, the line part is intended to decouple other movements of the internal combustion engine, in particular load-changing movements, and also thermal expansion movements from the continuing exhaust line and thus from the exhaust system.It is usually necessary in such bellows or line parts to radially narrow or widen the smoothly cylindrical connection section of the bellows, for example in order to be able to connect the line part or the bellows to another line part. The mechanical upsetting or widening of the connection section frequently used for this regularly entails the disadvantage that the connection section, which like the bellows itself is usually made of a metal, tends to form folds in an uncontrolled manner due to the mechanical deformation. It is therefore only possible, due to great material and cost, to vary a diameter of the connection section in a targeted manner.DE 20 2007 004 757 U1 discloses a decoupling element with insulation and with a bellows, which has a smoothly cylindrical connection section. For fixing an insulating material, the bellows can have axially extending, recessed regions in the smoothly cylindrical connection section.From DE 43 28 858 A1 an articulated connection of two pipe parts is known, in which two substantially aligned pipe parts arranged with their ends opposite each other are connected to each other by a line element in the form of a corrugated pipe or bellows, which connects the pipe parts tightly to each other.WO 2014 / 183 773 A1 discloses a flexible line element which has two smoothly cylindrical connection regions and an annularly corrugated intermediate region. This intermediate region can have a separately formed and in particular an unwelled central section in the middle of the line element.DE 540 246 A teaches a method for producing highly elastic corrugated or spring tubes which likewise have smoothly cylindrical connection ends.EP 2 620 683 A1 shows a composite pipe for air conditioning and ventilation technology, which is oval in shape and has wave crests arranged circumferentially. Wave troughs welded continuously to an inner tube are formed between adjacent wave peaks. Between adjacent wave crests, wave trough sections are formed which are welded to the inner tube only over a partial region.DE 696 00 074 T2 discloses a flexible tubular connecting element for the exhaust gas systems of motor vehicles, having a tubular element made of metal which is designed in the manner of a bellows and has end regions within which two tubes are welded in, so that they are connected to one another by means of the connecting element.The invention is based on the object of specifying a bellows with a terminal connection section, the internal cross section of which can be varied in a simple manner without wrinkling in the connection section in order to facilitate or even make possible the connection to another line part or the like.The invention also addresses the object of providing a line part with such a bellows, an internal component and an annular fixing component, in which line part and internal component are connected to one another in a simple and secure manner.Furthermore, the object of the invention is to specify a method for producing a bellows according to the invention.This object is achieved by a bellows having the features of claim 1, by a line part having the features of claim 8, by a method for producing a bellows having the features of claim 13 and by an exhaust line having the features of claim 18.In the case of a bellows of the type described at the beginning, the object is achieved according to the invention in that the wave peaks and wave valleys are oriented in the circumferential direction in the region of the second corrugation. Preferably, the effective inner radius of the bellows in the region of the second corrugation is reduced compared to the effective inner radius of the connection section. The connection section configured in this way has an effective diameter or radius that can be adjusted in a targeted manner and can in this way serve for an advantageous connection to a counterpart, for example a terminal connection section of a pipeline.When a "(smoothly cylindrical) connection section" is mentioned in the context of the invention, this generally means that part of the bellows which has not been substantially co-formed during the formation of the first corrugation and which, according to the prior art, has been used for connection purposes substantially unchanged. In the present case, however, the connection section has still been subsequently formed and thus likewise has a (partially) corrugated shape (the second corrugation). This is different from the first corrugation in the annularly corrugated section of the bellows.The effective inner radius of the bellows in the region of the connection section is defined as the distance between the longitudinal axis of the bellows and a point of the connection section in the region of the second corrugation, which point is closest to the longitudinal axis. Approximately, all wave troughs in the region of the second corrugation each have the same distance from the longitudinal axis of the bellows. The said distance thus corresponds approximately to the distance between the longitudinal axis and a trough of the shaft of the cylindrical connection section.The effective outer radius of the bellows in the region of the connection section is defined as the distance between the longitudinal axis of the bellows and a point of the connection section in the region of the second corrugation, which point is at the furthest distance from the longitudinal axis. Approximately, all wave peaks at the apex point each have the same distance from the longitudinal axis of the bellows.The said distance thus corresponds approximately to the distance between the longitudinal axis and a wave crest of the cylindrical connection section.The effective inner radius of the connection portion, on the other hand, is an inner radius which the connection portion has before a radial widening or narrowing thereof (e.g. during the forming for forming the second corrugation). In this case, the skilled person readily recognizes that the connection section has been radially expanded or narrowed, since when a mechanical forming method is used, at least a partial region of the smoothly cylindrical connection section is obtained in its original shape in a recognizable manner, or otherwise corresponding tool tracks can be recognized when the connection section is acted on directly by a tool.In the case that the second corrugation is formed in the connection section by radial widening, the effective inner radius of the bellows in the region of the second corrugation corresponds to the effective inner radius of the connection section, and the effective outer radius of the bellows in the region of the second corrugation is greater than the effective inner radius of the connection section. In the case where the corrugation is introduced into the connection section by radial narrowing from the outside, the effective outer radius of the bellows in the region of the second corrugation corresponds--with neglected wall thickness or material thickness of the connection section--to the effective inner radius of the connection section, and the effective inner radius of the bellows in the region of the second corrugation is smaller than the effective inner radius of the connection section. The second corrugation can also be formed by linking radial widening and radial narrowing into the connection section. In this case, the effective inner radius of the connection section is between the effective inner radius of the bellows in the region of the second corrugation and the effective outer radius of the bellows in the region of the second corrugation in terms of amount.The wave peaks and wave valleys of the ring-corrugated section (first corrugation) are oriented substantially transversely to a longitudinal axis of the bellows and have a substantially purely circumferential extension component (transverse corrugations).By a different configuration of the difference between corrugation peak and corrugation trough or between the effective outer radius and the effective inner radius of the bellows in the region of the second corrugation and the effective inner radius of the connection section, the connection section can be radially expanded or narrowed in a targeted manner. The connection section has no folds-apart from the defined second corrugation (see above).According to the invention, the wave peaks and wave valleys in the region of the second corrugation are oriented in the circumferential direction. Preferably, the wave peaks and wave valleys can be oriented purely circumferentially (transverse waves). The wave peaks and wave valleys in the region of the second corrugation thus have an approximately identical orientation as the wave peaks and wave valleys of the first corrugation, which, as mentioned above, are oriented substantially transversely with respect to a longitudinal axis of the bellows (transverse waves).Preferably, the bellows has a smaller effective inner radius in the region of the connection section, with respect to the ring-corrugated section of the bellows. The effective inner radius of the bellows is defined in the annularly corrugated portion of the bellows as a shortest distance between the longitudinal axis and a corrugation trough of the annularly corrugated portion. By virtue of this configuration of the cylindrical connection portion, an optional internal component can be arranged within the bellows and fixed to the latter in the connection portion in such a way that the internal component is not in contact with the annularly corrugated portion of the bellows. As a result, the annularly corrugated section of the bellows can be easily and better protected from damaging influences caused by a fluid guided in the interior of the inner component. A thermal decoupling of the fluid guided in the interior of the inner component from the annularly corrugated section of the bellows is also facilitated as a result. Furthermore, the advantageous development leads to an improved flow behavior of the fluid within the bellows or the inner component.In a preferred development of the bellows according to the invention, the connection section of the bellows has, in a transition region to the annularly corrugated section, a radial bulge in the manner of a pre-wave which is generally smaller than a wave crest in the annularly corrugated section. Due to the radial bulge of the connection section of the bellows, the ring-corrugated section of the bellows can be protected from damaging mechanical action by any components axially pushed onto the connection section. The radial bulge can also serve as a stop for parts / components or the like pushed axially onto the connection section.Preferably, the bellows has a connection section at each of the two ends, which connection section has at least in regions the second corrugation with corrugation peaks and corrugation valleys, which corrugation is different from the first corrugation. In the two regions of the second corrugation, the effective inner radius of the bellows is different from the effective inner radius of the connection section, preferably reduced with respect to the effective inner radius of the connection section. This makes it possible to easily provide connections to further line parts etc. on both sides of the bellows.In an advantageous development of the invention, the bellows has at least one first annularly corrugated section and at least one second annularly corrugated section and at least one intermediate section lying therebetween, which is different from the annularly corrugated sections. The series arrangement of a plurality of annularly corrugated sections and one or more intermediate sections lying therebetween enables a specific adaptation of the vibration damping behavior of the bellows to vibration states which occur. The intermediate sections lying between them can facilitate the connection of an inner component and / or an outer component, in particular a wound hose or metal braid / knitted fabric, to the bellows.The intermediate section can advantageously have a wave structure with wave peaks and wave valleys comparable to the connection section. The wave peaks and wave valleys can extend in the circumferential direction in the region of the connection section corresponding to the wave peaks and wave peaks. Alternatively, they may extend in the axial direction. As a result, the bellows has the same advantages in the intermediate section as in its connection section, which can be used for connecting further components. In addition, at least one region of the intermediate portion can be curved radially outwards, i.e. the intermediate portion and optionally the axial wave peaks and wave valleys have a radial curvature outwards in this region.Advantageously, the bellows according to the invention can be a component of a line part, which line part is provided in particular for use in an exhaust system of a motor vehicle. In this case, the line part comprises, in addition to the bellows according to the invention or a refinement thereof, an inner component, in particular a wound hose or liner, which is radially surrounded by the bellows, and at least one annular fixing element, in particular a sleeve, which radially surrounds the bellows and the inner component over the entire circumference at least in a region of the connection section. Preferably, the inner component essentially only has contact points with the connection section of the bellows in the region of the wave troughs.As already explained above, the corrugated structure of the connection section of the bellows allows the effective diameter of the connection section to be adjusted in a targeted manner. In particular, the effective diameter of the connection section can thereby be adjusted without using an additional inner sleeve, which previously had to be regularly attached within the connection section, in such a way that the inner component in the ring-corrugated section of the bellows is arranged radially spaced apart from the bellows. This radial distance is usually necessary in order to reduce wear of the bellows due to friction. The saving of the additional inner sleeve leads to savings in weight, which is particularly advantageous especially in the motor vehicle sector.In a preferred development of the line part, the connection section of the bellows has a radial bulge or pre-shaft in a transition region to the annularly corrugated section, which bulge or pre-shaft is designed for axial support of the annular fixing element. Due to the radial bulge of the connection section of the bellows, the ring-corrugated section of the bellows is protected from damaging mechanical action by the ring-shaped fixing element. The radial widening can also be used in a targeted manner as an axial support or stop for the annular fixing element and thereby facilitates the attachment of the annular fixing element on the connection section of the bellows. In particular, this allows exact axial positioning of the ring-shaped fixing element.Advantageously, an axial extent of the region in which the connection portion has the corrugation is at least as large in terms of amount as an axial extent of the annular fixing element. As a result, the connection between the connection section and the annular fixing element is significantly simpler and more reliable to produce.In an advantageous development of the line part according to the invention, the annular fixing element, the bellows and the inner component are in a force-fit connection with one another in a region of the connection section, in particular by radial pressing. Such a connection is well known from the prior art and is therefore simple and reliable to implement. Even after radial pressing has taken place, the corrugation of the connection section remains at least partially present, i.e. with a reduced radial distance between the corrugation peaks and the corrugation valleys or with a reduced corrugation height.Preferably, the inner component and the intermediate section of the bellows present in a corresponding refinement have a material-locking and / or force-locking connection. A cohesive connection can be effected, for example, by welding, the force-fit connection can be effected, in particular, by radial pressing, in particular if the intermediate section likewise has a corrugation or corrugation structure, as described above. Such a connection of the inner component to the intermediate portion of the bellows can improve the damping properties or the vibration behavior of the entire bellows. In this case, the connection of the inner component and the intermediate section of the bellows usually does not have a disadvantageous effect on the mobility of the bellows.Preferably, a bellows according to the invention is produced essentially by means of a method with the following sequence: a cylindrical connection section of a conventional bellows with an annularly corrugated section and in each case a smoothly cylindrical connection section is passed in the circumferential direction between a first roller and a second roller. The outer surfaces of the two rollers have a wavy structure. The wavy structure of the first roller and of the second roller is configured in each case in such a way that the structure of the two outer surfaces of the two rollers is impressed into the cylindrical connection section guided through between the rollers. The two rollers are operatively connected. This is to be understood to mean that both rollers together cause the structure of their outer surfaces to be impressed into the connection section. In order to be able to pass through the smoothly cylindrical connection section between the two rollers, these each rotate with a respective opposite direction of rotation. It is within the scope of a further development of the invention to use an identical or similar method in order to produce a corresponding corrugation structure or corrugation in the intermediate section.In an advantageous development of the method, after the corrugation is impressed into the connection section or into the connection sections, an annular fixing element, in particular a sleeve, is drawn axially onto the connection section or the connection sections. After the ring-shaped fixing element has been tightened, it is radially pressed together with the relevant connection section of the bellows and with the inner component radially surrounded by the bellows. As a result, the inner component, the connection section and the fixing element are connected to one another. The pressing process represents a standard method and, in conjunction with a bellows according to the invention or its second corrugation in the region of the connection section, enables a particularly advantageous, simple and secure connection of the bellows, the annular fixing element and the inner component to one another.In order to improve the connection of the connection section to the ring-shaped fixing element, these are preferably welded to one another. Particularly preferably, the inner component and an optional outer component, in particular a wound hose or metal mesh / knitted fabric, are additionally welded to the annular fixing element and the connection section or the connection sections of the bellows.In an advantageous development of the method, the inner component and the bellows are radially expanded in the region of the intermediate section-if present-and pressed and / or welded together, optionally together with an optional outer component, in particular a wound hose or metal braid / knitted fabric. Due to the radial expansion or the pressing and / or welding of the inner component and the bellows, as well as optionally the optional outer component, in the region of the intermediate section, a connection of the components is particularly simple and efficient to produce.A line part according to the invention can be connected to at least one further pipe part. Both the line part and the line part connected thereto are preferably part of an exhaust line of a motor vehicle.Further preferred features and embodiments of the invention are evident from the following description of exemplary embodiments and from the drawings. It shows: FIG. 1 shows a bellows in a longitudinal section; FIG. 2 shows an alternative embodiment of the bellows in a longitudinal section; FIG. 3 shows a line part with a bellows according to FIG. 1 in a longitudinal section; FIG. 4 shows an alternative embodiment of the line part with a bellows according to FIG. 2 in a longitudinal section; FIG. 5 shows a line part in a cross section; FIG. 6 shows a second alternative embodiment of the bellows in a longitudinal section; FIG. 7 shows a third alternative embodiment of the bellows in a longitudinal section; FIG. 8 shows a second alternative embodiment of the line part in a longitudinal section; FIG. 9 shows a third alternative embodiment of the line part in a longitudinal section; FIG. 10 shows two rollers for producing a bellows according to the invention in a longitudinal section; and FIG. 11 shows an exhaust gas line with a line part according to FIG. 3.FIG. 1 shows a bellows 1 in a longitudinal section. The bellows 1 has two cylindrical connection sections 3, 3' and an annular corrugated section 2 lying therebetween with a first corrugation. Both cylindrical connection sections 3, 3' are substantially identical. They have a corrugation structure or second corrugation with corrugation peaks 4 and corrugation valleys 5, which are oriented in the axial direction (longitudinal corrugations). Within the scope of the invention, the wave peaks 4 and wave valleys 5 can also have a circumferential extension component for the second corrugation or can be oriented purely circumferentially (transverse corrugations).A region 12, 12', in which the connection sections 3, 3' have the mentioned wave-shaped structure or second corrugation, takes up approximately an entire axial length of the cylindrical connection section 3, 3' in the present embodiment. The annularly corrugated section 2 of the bellows 1 is designed in the manner of an annularly corrugated hose having corrugation troughs 9 and corrugation peaks 10 which are oriented approximately orthogonally to the corrugation troughs 5 and corrugation peaks 4 of the cylindrical connecting sections 3, 3' (first corrugation; transverse corrugation).The annularly corrugated section 2 of the bellows 1 has an effective inner radius r eff2. This is defined as a shortest distance between a longitudinal axis L of the bellows 1 and a trough 9 of the corrugated section 2 of the bellows 1.An effective inner radius r eff1 of the bellows 1 is defined as the shortest distance between the longitudinal axis L and a trough 5 of the shaft of the cylindrical connecting section 3, 3'. The effective inner radius r eff1 is smaller in absolute value than the effective inner radius r eff2 of the ring-corrugated section 2 of the bellows 1.The corrugation structure or corrugation of the cylindrical connection sections 3, 3' brings with it the advantage on the one hand that the effective inner radius r eff1 of the bellows 1 can be varied without uncontrolled wrinkling of the material of the connection section 3, 3'-apart from the defined longitudinal corrugations. In particular, the effective inner radius r eff1 of the bellows 1 can thereby be adjusted without using an additional inner sleeve (cf. FIG. 3 et seq.) which in the prior art had to be regularly arranged within the connection section 3, 3', with a corresponding weight saving, in such a way that an inner component arranged in the bellows 1 is arranged in the annularly corrugated section 2 of the bellows 1 radially spaced apart from the bellows 1.The corrugated structure or corrugation of the connection section 3, 3' thus produced can also be used to serve as a locking mechanism for the bellows 1 or the cylindrical connection section 3, 3' of the bellows 1 when being connected to a correspondingly configured counterpart in order to exclude a rotation about the longitudinal axis L.FIG. 2 shows a first alternative embodiment of the bellows 1, only the differences of the bellows 1 in FIG. 2 with respect to FIG. 1 will be discussed below. In addition to the region 12 with the corrugated structure or corrugation, the cylindrical connection section 3, 3' has a radial bulge 11, 11' in a transition region 19 to the annularly corrugated section 2. The radial bulge 11, 11' of the connecting section 3, 3' of the bellows 1 makes it possible to protect the annularly corrugated section 2 of the bellows from damaging mechanical action by any components pushed axially onto the connecting section 3, 3'. The radial bulge 11, 11' can serve as a stop for parts / components or the like pushed axially onto the connection section 3, 3'.FIG. 3 shows a line part 6. The line part 6 comprises a bellows 1 according to FIG. 1 and an inner component 7, which will be discussed in more detail below. In both cylindrical connection sections 3, 3' of the bellows 1, an annular fixing element 8, 8' in the form of a sleeve is arranged in a subsection of the region 12, 12', in which the cylindrical connection sections 3, 3' have a longitudinal wave structure. Inner component 7, cylindrical connecting section 3, 3' and annular fixing component 8, 8' are pressed together and thereby connected to one another in a force-fitting manner. In addition, a cohesive connection of the three components can be provided, in particular by punctiform or full-circumference welding.An axial extension Δx 1 of the region 12, 12', in which the connection section 3, 3' has the corrugation, is in the present case approximately 50% greater than an axial extension Δx 2 of the sleeve 8, 8'. In other words, the region 12, 12' is not surrounded by the sleeve 8, 8' in approximately one third of its axial extent Δx 1.The inner component 7 is designed as a wound hose in the present case, to which the invention is, however, in no way limited. In particular, the inner component 7 can also be designed in the manner of a flame tube. The inner component 7 protects the annularly corrugated section 2 of the bellows 1 in a manner known per se from damage and thermal action and ensures a defined flow behavior of a fluid which is guided in the bellows 1. The sleeve 8, 8' surrounds the respective connection section 3, 3' of the bellows 1 over its entire circumference and has contact points with the connection section 3, 3' in a region of the axially oriented wave crest 4 of the wave structure or wave.FIG. 4 shows a line part 6' with a bellows 1 according to FIG. 2, and correspondingly the difference between the line part 6' from FIG. 4 and the line part 6 from FIG. 3 lies in the fact that the connection section 3, 3' of the bellows 1 has a radial bulge 11, 11' in a transition region 19, 19' to the ring-corrugated section 2 of the bellows 1 (cf. FIG. 2). The radial bulge 11, 11' of the connecting section 3, 3' of the bellows 1 can protect the annularly corrugated section 2 of the bellows 1 from a damaging mechanical action by the annular fixing component 8, 8' axially pushed onto the connecting section 3, 3'. The radial bulge 11, 11' can also function as an axial support for the annular fixing element 8, 8' and thus facilitate the attachment of the annular fixing element 8, 8' to the connection section 3, 3' of the bellows 1. In particular, this allows exact axial positioning of the ring-shaped fixing element 8, 8'.FIG. 5 shows a cross section of a cylindrical connection section 3, which is arranged radially between an inner component 7, in particular a winding tube or a flame tube, and an outer annular fixing component 8, in particular a sleeve. The cylindrical connection section has a corrugation with corrugation peaks 4 and corrugation valleys 5. The effective inner radius r eff1 of the bellows 1, as explained above with reference to the description of FIG. 1, is defined as the shortest distance between the longitudinal axis L (which here runs perpendicular to the plane of the drawing through the center point M of the cylindrical connection section 3) and a trough 5 of the shaft of the cylindrical connection section 3. It is assumed here that all wave troughs 5 of the cylindrical connection section 3 have approximately the same radial distance from the center point M or the longitudinal axis L. The same assumption applies to the wave crests 4 of the cylindrical connection section 3. an effective outer radius r außen of the bellows 1 is defined as the shortest distance between the longitudinal axis L and a wave crest 4 of the connection section 3.A person skilled in the art readily recognizes that the connection section 3 has been radially constricted, since at least a partial region of the smoothly cylindrical connection section 3 is obtained in its original shape. An effective inner radius r GZ of the connection section 3 is an inner radius which the connection section 3 has exhibited substantially continuously before the radial narrowing effected in the present case and has still at least in partial regions. Due to the present radial narrowing of the connection section 3, the effective outer radius r außen of the bellows 1 in the region of the second corrugation corresponds--with neglected wall thickness or material thickness--to the effective inner radius r GZ of the connection section 3.The ring-shaped fixing component 8 has contact points with the cylindrical connection section 3 in a region of the wave crest 4. The inner component 7 has points of contact with the cylindrical connection section 3 in a region of the wave troughs 5.By means of a radial pressing of inner component 7, connecting section 3 and fixing component 8, the three components mentioned are connected to one another in a force-fitting manner. The original corrugation of the connection section 3 has been smoothed to a certain extent (i.e. a corrugation amplitude between corrugation peak 4 and corrugation trough 5 is smaller than before the pressing); however, it is still present even after the pressing. Due to the described arrangement of the inner component 7 and the fixing component 8 and due to the corrugated structure of the connection section 3, cavities H are located between the outer fixing component 8 and the inner component 7. However, it can also be advantageous not to fill the cavities H at least partially, in order to thus bring about an intermediate layer for thermal insulation of the fluid guided in the bellows 1.In FIG. 6, a bellows 1' is shown which has a first annularly corrugated section 2 and a second annularly corrugated section 2a. An intermediate portion 14 is formed axially between the first annular corrugated portion 2 and the second annular corrugated portion 2 a. The intermediate portion 14 has a wave structure with wave peaks 4 aand wave valleys 5 aor which are oriented in an axial direction (longitudinal waves). Within the scope of the invention, the wave peaks 4 aand wave valleys 5 acan also have an (at least partially) orientation in the circumferential direction. Thus, the intermediate portion 14 is structurally different from the two ring-corrugated portions 2, 2a.In the region of the intermediate section 14, the bellows has an effective inner radius r eff3 which is defined analogously to the effective inner radius r eff1 of the bellows 1' in the region of the connection section 3, 3'. In the present case, the effective inner radius r eff3 of the bellows 1' in the region of the intermediate section 14 corresponds in terms of amount approximately to the effective inner radius r eff1 of the bellows 1' in the region of the connecting section 3, 3'. This does not necessarily have to be the case within the scope of the invention. However, it is essential that the effective inner radius r eff3 of the bellows 1' in the region of the intermediate section 14 is smaller than the effective inner radius r eff2 of the bellows 1' in the region of the annularly corrugated region 2 of the bellows 1'.In FIG. 7, analogously to FIGS. 2 and 4, the cylindrical connection section 3 of the bellows 1 additionally has a first radial bulge 11 in a transition region 19 to the first annularly corrugated section 2. In a transition region 19 cto the second annularly corrugated section 2 a, the corresponding cylindrical connection section 3' of the bellows 1 has a second radial bulge 11 c. In addition, the bellows 1' has a third radial bulge 11a in a transition region 19a to the first ring-corrugated section 2 and a fourth radial bulge 11b in a transition region 19b to the second ring-corrugated section 2a. An axial and radial extent of the bulges 11, 11 a, 11 b, 11 cis in the present case approximately the same in terms of amount. However, different configurations of the bulges 11, 11 a, 11 b, 11 care also possible. Each of the bulges 11, 11 a, 11 b, 11 cfunctions to protect the first annularly corrugated section 2 or the second annularly corrugated section 2 afrom mechanical damage, as already described.FIG. 8 shows a line part 6" which comprises a bellows 1' with a first annularly corrugated section 2 and a second annularly corrugated section 2a. Analogously to FIG. 6, an inner component 7 in the form of a wound hose is arranged in the bellows 1' axially running through the complete bellows 1'. The two connection sections 3, 3' are partially surrounded over their entire circumference by an annular fixing component 8, 8'. Reference is explicitly made to the specific type of configuration of the inner component 7 and the annular fixing component 8, 8' disclosed with reference to FIG. 6 and the advantages associated therewith.In contrast to the embodiment in FIG. 6, the intermediate region 14 has a region 15 with a radial bulge. In the region 15 of the radial bulge, the inner component 7 and the intermediate region 14 of the bellows 1' are connected to one another in a force-fitting manner by radial pressing. Alternatively or additionally, a cohesive connection of the two components 14, 15 is also possible, in particular by welding. Such connection of the internal component 7 to the intermediate portion 14 of the bellows 1' improves the damping properties of the entire bellows 1'. The connection of the inner component 7 and the intermediate section 14 of the bellows 1' does not have a disadvantageous effect on the mobility of the entire bellows 1'. Optionally, an outer component, not shown, in particular a wound hose or metal mesh / knitted fabric, can also be provided, which outer component partially or completely surrounds the bellows 1', and which outer component is preferably connected to the bellows 1' and / or the fixing component 8, 8' in a region of the connection sections 3, 3' and / or the intermediate section 14, in particular by pressing and / or welding.In an alternative embodiment, the intermediate section 14 can also be surrounded over its entire circumference by an annular fixing component (not shown in FIG. 8 ), in particular a sleeve. This may result in an improved connection of the inner component 7 and the intermediate section 14 of the bellows 1' or additionally with the optional outer component.FIG. 9 shows a line part 6''' which is designed structurally analogously to the embodiment in FIG. 8. In addition, the line part 6''' has a first radial bulge 11 in a transition region 19 to the first annularly corrugated section 2. In a transition region 19 cto the second annularly corrugated section 2 a, the corresponding cylindrical connection section 3' has a second radial bulge 11 c. In addition, the bellows 1' has a third radial bulge 11a in the region of the intermediate section 14 in a transition region 19a to the first annularly corrugated section 2 and a fourth radial bulge 11b in a transition region 19b to the second annularly corrugated section 2a.FIG. 10 shows a first roller 16a and a second roller 16b, as can be used for producing a bellows 1, 1'. An outer surface A 1 of the first roller 16a has a first wavy structure. An outer surface A 2 of the second roller 16a has a second wavy structure. The two wave-shaped structures are configured to cooperate with one another. This means, for example, that a wave crest of the first roller 16 aengages with a wave trough 16 bof the second roller 16 b.The two rollers 16 a, 16 brotate in opposite directions about their respective central axis. The cylindrical connecting section 3 of a bellows 1, 1' is passed between the two rollers 16a, 16b. In this case, both rollers 16 a, 16 bappear a radial force on the connection section 3, so that the structure of the two rollers 16 a, 16 bis impressed into the connection section 3 of the bellows 1, 1'.It is within the scope of the invention if a comparable method is used to emboss a wave-shaped structure or corrugation into the cylindrical connection section 3, 3' of the bellows 1, 1', the wave peaks 4 and wave valleys 5 of which are preferably aligned in the axial direction. It is also within the scope of the invention to use a similar or similar method in order to produce a corresponding wave structure in the intermediate section 14.In Fig. 11 an exhaust pipe 17 is shown which comprises a pipe part 6 and a further pipe part 18 which are connected to each other. The connection can be effected in a force-fit and / or firmly bonded manner, in particular by radial pressing, welding or soldering. The exhaust line 17 is provided and designed for use in an exhaust system of a motor vehicle.

Claims

Bellows (1, 1') having at least one annularly corrugated section (2, 2a), in which the bellows (1, 1') has a first corrugation with corrugation peaks (10) and corrugation valleys (9) which are oriented in the circumferential direction, and having at least one terminal connection section (3, 3'), in which the bellows (1, 1') has, at least in regions, a second corrugation with corrugation peaks (4) and corrugation valleys (5), which second corrugation is different from the first corrugation, in which, in a region of the second corrugation, an effective inner radius (r eff1) of the connection section (3, 3') is different from an effective inner radius (r eff2) of the bellows (1, 1') in a region of the first corrugation, wherein the effective inner radius (r eff2) of the bellows (1, 1') in the region of the first corrugation is defined as a shortest distance between a longitudinal axis (L) of the bellows (1, 1') and a corrugation trough (9) of the annularly corrugated section (2, 2a), and wherein the effective inner radius (r eff1) of the connection section (3, 3') is defined as a distance between the longitudinal axis and a point of the connection section (3, 3') in the region of the second corrugation, which point is closest to the longitudinal axis (L), characterized in that the corrugation peaks (4) and corrugation troughs (5) in the region of the second corrugation are oriented in the circumferential direction.The bellows (1, 1') according to claim 1, wherein the connection portion (3, 3') has a smaller effective inner radius (r eff1) with respect to the annularly corrugated portion (2, 2a) of the bellows (1, 1').Bellows (1, 1') according to Claim 1 or 2, in which the connection section (3, 3') has a radial bulge (11, 11c) in a transition region (19, 19c) to the annularly corrugated section (2, 2a) of the bellows (1, 1').Bellows (1, 1') according to one of Claims 1 to 3, which has a connection section (3, 3') each at both ends with the relevant features from Claim 1.The bellows (1') according to any one of claims 1 to 4, comprising at least one first annularly corrugated portion (2) and at least one second annularly corrugated portion (2a) and at least one intermediate portion (14) lying therebetween and different from the annularly corrugated portions (2, 2a).Bellows (1') according to Claim 5, in which the intermediate section (14) has, at least in regions, a wave structure with wave peaks (4a) and wave valleys (5a), which wave peaks (4a) and wave valleys (5a) extend in the axial direction and / or in the circumferential direction.Bellows (1') according to Claim 5 or 6, in which at least one region (15) of the intermediate section (14) is curved radially outwards.Line part (6) with a bellows (1, 1') according to one of Claims 1 to 7 and an inner component (7) which is radially surrounded by the bellows (1, 1'), and with at least one annular fixing element (8, 8') which radially surrounds the bellows (1, 1') and the inner component (7) over the entire circumference at least in a region of the connection section (3, 3').Line part (6', 6''', 6''') according to claim 8, wherein the connection section (3, 3') of the bellows (1, 1') has a radial bulge (11, 11c) in a transition region (19, 19c) to the ring-corrugated section (2, 2a), which bulge is configured for axial support of the ring-shaped fixing element (8, 8').Line part (6, 6', 6''', 6''') according to claim 8 or 9, wherein an axial extent (Δx 1) of the region (12, 12') in which the connection portion (3, 3') has the second corrugation is at least as large in terms of amount as an axial extent (Δx 2) of the annular fixing element (8, 8').Line part (6, 6', 6", 6"') according to one of claims 8 to 10, in which the annular fixing element (8, 8'), the bellows (1, 1') and the inner component (7) are in a force-fit connection with one another in a region of the connection section (3, 3'), in particular by radial pressing.Line part (6''', 6''') according to one of claims 8 to 11 with a bellows (1, 1') according to one of claims 5 to 7, in which line part (6''', 6''') the inner component (7) and the intermediate section (14) of the bellows (1, 1') have a connection with a material fit and / or a force fit, in particular produced by radial pressing.Method for producing a bellows (1, 1') according to one of Claims 1 to 7, comprising: a) passing a cylindrical connection section (3, 3') of the bellows (1, 1') in the circumferential direction between a first roller (16a) and a second roller (16b), the outer surfaces (A 1, A 2) of which have a wavy structure and which are operatively connected to one another, b) embossing the structure of the outer surfaces (A 1, A 2) of the two rollers (16a, 16b) in the connection section (3, 3').Method according to claim 13 for producing a bellows (1') according to one of claims 5 to 7, in which the method steps a) and b) are also carried out with respect to the at least one intermediate section (14).Method according to Claim 13 or 14, in which - after the corrugation has been impressed into the connection section (3) or into the connection sections (3, 3'), an annular fixing element (8), in particular a sleeve, is drawn axially onto the connection section (3) or the connection sections (3, 3'), - after the annular fixing element (8) has been drawn on, it is pressed radially onto the connection section (3) or the connection sections (3, 3') of the bellows (1, 1') and onto an inner component (7) which is radially surrounded by the bellows (1, 1').Method according to claim 15, in which the annular fixing element (8), the connection section (3) or the connection sections (3, 3') of the bellows (1, 1') and the inner component (7) are connected to one another in a materially bonded manner, in particular welded.Method according to claim 15 or 16, in which the inner component (7) and the bellows (1') are radially expanded and connected to one another in a force-fitting manner, in particular by pressing, and / or in a materially integral manner, in particular by welding, in the region of the intermediate portion (14).Exhaust line (17) having a line part (6, 6', 6''') according to one of Claims 8 to 12 and at least one further line part (18) which is connected to the line part (6, 6', 6'').

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