WO2012013584A1

WO2012013584A1 - Screw connecting system

Info

Publication number: WO2012013584A1
Application number: PCT/EP2011/062594
Authority: WO
Inventors: Wolfgang Dietmar Gellermann
Original assignee: Wolfgang Dietmar Gellermann
Priority date: 2010-07-30
Filing date: 2011-07-22
Publication date: 2012-02-02
Also published as: DE102010035503A1; EP2598731A1

Abstract

The invention relates to a screw connecting system (10/1, 10/2, 10/3) for fastening a machine element (11; 40) to a block-shaped carrier, such as an exhaust manifold (40) on the engine block (12) of an internal combustion engine, having at least one threaded bolt (21) screwed into a threaded hole (22) of the block (12) and having an outer thread segment (24/a) penetrating through an opening of a flange element of the machine element to be fixed, onto which a threaded nut (27) for fixing the machine element can be screwed, said nut being secured in the assembly configuration against loosening from the threaded bolt. According to the invention, the threaded bolt (21) has an securing segment (23) with edged outer contour between the inner threaded segment (24/i) and the outer threaded segment (24/a) for securing against turning out of position, said securing segment engaging positively, in the assembled configuration, with the edge of an opening of a securing element (28) rotationally fixed to the machine element, said edge being designed to be complementary at least in segments to the contour of the securing segment (23), or with a functionally corresponding opening (18/o, 8/u) of the machine element itself. The edged fixing segment of the threaded bolt (21) is designed as a short square profile piece that is displaceable guided with opposite profile end faces on parallel longitudinal edges (19/o and 19/u) of opposite elongated holes (18/g and 18/u) of the fastening flange (14) of the body (11) to be fastened.

Description

The invention relates to a screw connection system for fastening a machine element to a block-shaped support, for. B. an exhaust manifold on the engine block of an internal combustion engine and with the other, mentioned in the preamble of claim 1, generic characteristics.

Such multi-part systems are used in particular for securing screw connections, including those with studs, with particular consideration of a caused by thermal influences displaceability of the components to be connected.

In known screw connection systems of this type anchored stud bolts are usually provided in threads of the supporting block, the free sections pass through holes of flanges, which can be supported on the stud bolts screw threaded nuts. As a result, a frictional fixation of the flanges or the elements provided with these, which are to be fastened to the block, achieved.

Due to vibrations or temperature effects, which may lead to different thermally induced dimensional changes of the supporting block and the flange element connected to the supported element, there may be relative movement of these elements and, as a result, loosening of stud bolts. It is therefore necessary to provide at least the nuts with suitable anti-rotation.

Common measures include gluing, pinning, wire locking or elements with claw edges; in case of high ambient temperature eliminates sticking. Pinning is generally too laborious and therefore not suitable for mass production.

In question is the use of suitable lock washers, which can withstand high temperatures easily and are also suitable for automated assembly.

Such lock washers are manufactured and sold by Nord-Lock. They are known under the name "Keilscheibensicherungspaa- re" in the Federal Republic of Germany by public prior use; However, they are not suitable in the known design and type of use for securing a composite of stud bolt and nut. The object of the invention is therefore to improve a Schraubverbindungssystem of the type mentioned in that it provides a reliable fixation of studs in their anchor threads and nevertheless with simple technical means that are suitable for use in a large-scale production, can be implemented.

This object is achieved by the characterizing features of claim 1 as set forth by the further claims variants and alternative designs. The screw connection system according to the invention provides a positive connection of the elements to be joined together and therefore a reliable backup engaged with each other standing parts against loosening and can be realized with simple design and inexpensive to produce additional elements that are also suitable for automatic assembly. It is particularly suitable for mounting exhaust manifolds on engine blocks or cylinder heads of internal combustion engines, in which the temperatures of the manifold, of hot fuel gases is flowed through, and the cooled engine block can be very different.

Further details of the screw connection system according to the invention will become apparent from the following description of exemplary embodiments with reference to the drawing. Show it

Fig. 1 a, a first embodiment of an inventive

Screw connection system in a schematically simplified, perspective exploded view;

1 b shows the screw connection system according to FIG. 1 a in its composite configuration, in section along a plane containing the central axis of a connection system

Fig. 2 shows another embodiment of an inventive

Screw connection system in one of the Figure 1 a corresponding representation. Fig. 3 shows a third embodiment of an inventive

Screw connection system with a two-piece designed locking washer, also in a Figures 1 a and 2 corresponding representation; 4 a shows the exhaust manifold according to FIG. 4 a in section along a central longitudinal axis of the manifold of the manifold according to FIG. 4 a. FIG. 4 a shows a schematic simplified simplified perspective view; FIG and the longitudinal axes of the gas outlet ducts of the engine block containing level;

Fig. 4c, the exhaust manifold according to FIGS. 4a and 4b, seen in the direction of the arrow IVc of Fig. 4b and

Fig. 4d is a view of the exhaust manifold in the direction of arrow IVd of

4c, in relation to this enlarged scale,

5 a shows a variant of the use of screw connection systems according to the invention for fastening an exhaust manifold on the engine block of a vehicle, in a representation corresponding to FIG. 4 c, FIG.

Fig. 5b used for one-sided fixation of the exhaust manifold according to Fig. 5a screw connection system and

5c shows the screw mechanism used for guiding thermally induced expansion movements of the manifold according to FIG.

Connection system, each in section along a plane containing the respective central axis of the screw connection system, Fig. 6a shows a further variant of the use according to the invention

Screw connection systems for mounting an exhaust manifold on the engine block of a vehicle, in one of the Fig. 4a corresponding representation, Fig. 6b for guiding thermally induced movements of the exhaust manifold according to Fig. 6a used guide element and Fig. 6c in combination with screw-connection systems of the arrangement of FIG. 6a usable lock washer.

In FIGS. 1 a and 1 b, a screw connection system is designated as a whole by 10/1, which for a secure fastening of a pipe 1 1, which is indicated only schematically, e.g. an exhaust pipe, at a block 12 indicated only schematically, e.g. the engine block of an internal combustion engine, is intended. This connection system 10/1 comprises, as a tube-side element, a flat plate-shaped flange 14, which is designed to be integral with the tube 1 1 as a rule. The mounting flange 14 is by means of two screw connection systems 10/1, which are arranged in the apparent from FIG. 1 a arrangement in opposite corner regions of the basic shape after tenten-shaped mounting flange 14, to a flat contact surface 16 (Fig. 1 b ), in such a way that the tube 1 1 connects closely to a dashed line indicated flow channel 17 of the (motor) block 12. The tube 1 1 is not shown in Fig. 1 b. The flange 14 of the tube 1 1 is provided with two elongated holes 18 / o and 18 / u, the longitudinal edges 19 / o and 19 / u all parallel to each other.

The connection system 10/1 comprises, as block-side connecting elements, a total of 21 threaded bolts which can be screwed into threaded bores 22 (FIG. 1 b) of the block 12 in order to implement block-fixed pedestal pins.

The threaded bolts 21 have two by a central portion 23 which is formed as a polygonal profile, in the specific embodiment shown in FIGS. 1 a and 1 b as a square profile, offset from each other threaded portions 24 / i and 24 / a same pitch and the same diameter. The one, inner threaded portion 24 / i imparts in the Gebrauchskonfigura- tion (Fig. 1 b), the tensile connection of the threaded bolt 21 with the engine block 12th

The centrally arranged square section 23 conveys the securing of the threaded bolt 21 against rotation about the central longitudinal axis 26 of the screw connection system 10 by engagement of opposite facet surfaces of the central section on mutually parallel longitudinal boundary surfaces of the respective oblong hole 18 / o or 18 / u. 1 and thereby conveys the result of the securing of the bolt 21 against disengagement from the threaded bore 22nd

The tight connection of the tube 1 1 and its tube flange 14 to the block 12 is achieved in this design of the connection system 10/1, characterized in that a nut 27 which is in meshing engagement with the outer threaded portion 24 / a, with bias on a so-called wedge securing washer pair 25 presses against a further securing disk 28, which in turn is supported on the outer surface 31 of the mounting flange 14 remote from the block and with the aid of embossed nubs 29 / I and 29 / r in the respective slot 18 / a or 18 / u is guided in the longitudinal direction and thereby simultaneously secured against rotation about the longitudinal axis 26 of the screw connection system.

This lock washer 28 mediates that the wedge locking washers of the wedge securing disk pair 25, which are known per se, are in force-positive connection both with this and with the lock washer 28, thus also securing the nut 27 against rotation, so that also the nut 27 can not solve relative to the outer threaded portion 24 / a; the threaded bolt 21 in turn is secured against loosening of the engine block 12 in that it prevents rotation about the central longitudinal axis of the fastening system by positive engagement between the square section 23rd and the respective slot 18 / a or 18 / u of the respective mounting flange 14 is secured.

In a known wedge-washer lock pair according to DIN 25 201, the wedge lock washers on their facing inner sides of wedge surfaces and have on the opposite outer sides radial ribs, in the given case with the attack surface of the mother, on the one hand, and with the lock washer 28, on the other , in positive engagement, when the nut is tightened. The slope of the wedge surfaces is chosen so that the angle α under which the wedge surfaces extend to a reference plane on which the central axis 26 of the system 10/1 is perpendicular, is always greater than the angle 2ß, if with ß the for the thread of the threaded bolt 21 is analogously determined angle, which results from the thread pitch, this, of course, provided that the two threaded portions of the threaded bolt have the same slope.

The pairs of discs are inserted so that the wedge surfaces lie on each other. If the nut is tightened in this case, the radial ribs of the lock washers form-fit the respective counter support. The prerequisite for this, of course, is that the lock washers have a significantly higher hardness than the material of the respective counter support. Relative movements of the disks are only possible between their wedge surfaces, wherein an increase in the preload force and thus a self-locking is achieved even with only a slight rotation of the composite in the release direction due to the wedge effect.

As a result, the effect of a splint is achieved, which prevents by form fit a loosening of the nut relative to the bolt.

The designated in Fig. 2 with 10/2 rotation-proof connection system according to structure and function of the system 10/1 construction and function analogue; it Therefore, it should be explained only with reference to differences that are given to the system 10/1 of FIG. 1 a.

Insofar as the same reference numbers are given in FIGS. 1a and 2, this is intended to include the reference to the description of FIG. 1a in order to avoid repetitions.

The only difference in this sense is the design of the lock washer 28/2, which is mounted clamped in the mounted configuration between the wedge lock securing pair 25, via which the nut 27 acts on the lock washer 28/2, and the flange 14.

The lock washer 28/2 of Schraubverbindungssystems 10/2 is guided laterally displaceable by means of a folded in the illustrated, special embodiment, narrow edge 32 which rests against an upper free flat narrow end face 33 of the flange 14 in the assembled configuration and secured against rotation ; Moving movements small stroke, the z. B. can be thermally induced, are possible, a rotation of the wedge securing pair 25 and the nut 27 about the central axis 26 of the system 10/2 is excluded, however; the securing of the threaded bolt 21 against rotation, by means of the central square portion 23 is realized in the same manner as in the system 10/1 of FIG. 1 a. Also shown in FIG. 3, denoted overall by 10/3 screw connection system is to the systems 10/1 and 10/2 according to the figures 1 a and 2 functionally analogous.

Unlike the embodiments shown in Figures 1 a 2 is merely that the threaded bolt 21/3 instead of a central polygonal portion 23 has a trained as external toothing, central portion 23/3, which with a complementary internal toothing 34 of Lock washer 28/3 meshes, which is otherwise functionally analogous to the lock washer 28 of FIG. 1 a.

The central opening 36, which according to the "axial" external toothing of the central portion 23/3 of the threaded bolt 21/3 has a serrated star-shaped clear cross-section, is arranged in the design chosen for explanation on a rib-shaped rib pointing towards the flange 14, which corresponds to a groove-shaped recess 37 on the opposite side, into which recess 37 a supplementary element 38 complementary to its shape is inserted, which has a central opening 39 whose diameter is at least approximately the diameter of the outer threaded section 24 / a of the threaded bolt 23 / 3 corresponds.

By this supplementary element, the wedge surface securing pair 25 facing abutment surface is leveled as it were and kept the surface sufficiently large for the positive engagement with the radial toothing of the facing wedge disk element.

To explain a typical use of screw connection systems 10/1, 10/2 and 10/3 according to the invention, as previously described with reference to FIGS. 1 a and 1 b and 2 and 3, reference is now made to FIGS. 4 a to 4 d, in which, using a screw connection system 10/4, which is implemented by a combination of features of the screw connection system 10/2 according to FIG. 2 with features of the screw connection system 10/3 according to FIG Altogether designated with 40 exhaust manifold on again schematically indicated engine block 12 of an example is shown as a drive unit of a passenger car serving internal combustion engine.

It should be expressly pointed out that the screw connection systems 10/1 and 10/3 according to FIGS. 1 a and 1 b and 3 are also useful. can be used log, and that any necessary adaptations of said alternative designs of screw-connection systems to the purpose of a motor expert on account of imputable expertise at any time possible and therefore not specifically need to be explained.

The explanatory choice of the screw connection system 10/4 is intended to illustrate a variety of design options according to the invention screw connection systems. The indication of reference symbols, which are given in drawing figures already explained above, also implies the reference to parts of description which have been made to the aforementioned FIGS. 1 a and 1 b, as well as 2 and 3.

Furthermore, without limitation of generality, i. merely for illustrative purposes implies that the exhaust manifold 40 according to FIG. 4a is an exhaust manifold of an engine with three exhaust exits, but in a case of extension or reflection in the case of more exhaust exits or V-engines, there is no special form. The manifold 40 comprises in the embodiment chosen for explanation three connecting pieces 41/1, 41/2 and 41/3, via the exhaust ducts 42/1, 42/2 and 42/3, (Fig. 4b), not for simplicity's sake illustrated combustion chambers of the engine are connected to a manifold 43 of the exhaust manifold 40 which extends substantially parallel to the motor axis of rotation, with its central axis 44 in the plane 45 extending through the central axes 46/1, 46/2 and 46/3 of the outlet channels 42/1, 42/2 and 42/3 of the engine block 12 is clamped (Fig. 4c).

The exhaust outlet 41/1, 41/2 and 41/3 are provided with them individually associated mounting flanges 14/1, 14/2 and 14/3 for fixing to the block 12. The connection nozzles and their flanges, which are connected to each other via the manifold 43, are used as a single piece. cast or welded parts made of stainless steel elements.

The mounting flanges 14/1, 14/2 and 14/3 are formed as the basic shape after rectangular or parallelogram-shaped plates with rounded corners with approximately equal lengths of the adjoining rectilinear edges and are each with two screw 10/4, which in the illustrated, special embodiment are arranged on the diametrically opposite corner regions, attached to the engine block 12.

According to the representations of FIGS. 4 a and 4 c, the mentioned fastening elements are coordinated with one another such that in the assembly configuration the central axes 47/1 o, 47/2 and 47/30 of the screw connection systems arranged on one side "above" the central longitudinal axis of the collecting tube 43 and the central axes 47/1 u, 47 / 2u and 47 / 3u are arranged below the central longitudinal axis 44 of the collecting tube arranged screw connection systems 10/4 in parallel planes 48 / o and 48 / u, on both sides of the central longitudinal axis 44th of the bend 40 containing, perpendicular to the engine block mounting surface 49 (Fig. 4b) standing longitudinal center plane 49 of the manifold 40 extend.

The screw connection systems 10/4 convey, in the special exemplary embodiment explained with reference to FIGS. 4 a to 4 c, the function of lower holders, wherein the lock washers 28/2 in the embodiment shown with free support edges 51 in the form of a circle segment are under bias level support portions 52 / s of the block 12 facing away from the outer boundary surface 52 of the mounting flanges 14/1, 14/2 and 14/3 are supported, which are thereby urged with their inner, the block facing the boundary surfaces 54 in abutment with this. Between the outer boundary surface 49 of the engine block and these facing inner boundary surfaces 54 of the mounting flanges 14/1 and 14/2 and 14/3, if necessary, existing sealing elements are, for the sake of simplicity, not shown.

The mounting position of the manifold 40 is on the one hand by form-locking engagement of a first block-fixed pin 56 with a blind hole-shaped recess 57 of the flanges 14/1, 14/2 or 14/3 of the manifold 40 and on the other by positive engagement of another block-solid, e.g. Cylindrical pin 58 with mutually parallel longitudinal edges 57 / o and 57 / u of a slot 56 or slot of a bend-resistant flange, marked in the illustrated, special embodiment of the left end flange 14/1 (Fig. 4c). The manifold or flange-side engagement elements, blind bore 57 and slot or slot 58 are arranged in the embodiment chosen for explanation such that the central axis 59 of the blind hole 57 in the median plane 45 of the manifold 40, the longitudinal center plane of the slot 58th is, of which the other guide pin 50/2, seen in the mounting configuration of the manifold 40, is received. It is understood that a deviation from this arrangement is possible if the other conditions require.

The block-resistant pins 56/1 and 56/2 in the illustrative example are in the form of cylindrical pins of the same diameter whose free height, measured from the contact surface 49 of the block 12, is smaller than the thickness of the flanges 14/1 and 14/3. on which the engagement elements of the flanges, blind hole 57 and slot or slot 58 are arranged, wherein the free ends of the pins through the bottom of the blind hole-shaped depression or the slot bottom of the receiving slot 58 of the left flange 14/1 (Fig. 4c ) are covered. In this type of engagement is defined by the engaging in the blind bore 57 pin 56/1, as seen in the view of FIG. 4b and in the plan view of FIG. 4c by the central axis 59, a fixing point of the manifold 40 defined at the no translatory movements of the manifold 40 relative to the block 12 are possible, but at most rotational relative movements of small angle about the axis 59 are possible, which may be due to thermal dimensional changes of the manifold 40 and the engine block, on the one hand because of different thermal expansion coefficients of the block material, For example, aluminum and the manifold material, such as gray cast iron or stainless steel, and on the other hand because of the different temperatures that the cooled engine block and the flowed through by the hot exhaust gases manifold 40 assume during operation of the engine. Because of the high temperatures occurring in the manifold 40, eg 800 ° C. to 1000 ° C., the thermally induced variations of the longitudinal and transverse dimensions in this case can be in the percentage range of the geometrical dimensions of the manifold present at normal temperature.

In order to avoid that due to thermal expansions, essentially of the bend 40, relative movements of the same relative to the block occur, which lead to loads on the screw connection systems 10/4, which in turn could lead to fractures of the threaded bolts, the screw connection systems 10/4 designed so that between the lock washers 28/4 and the flanges 14/1, 2, 3 of the manifold 40 sliding relative movements are possible, essentially in that the contact surfaces with which these elements abut each other, are smooth and sufficiently strong, and that between block-solid pedestals 61, on which the lock washers 28/4 of the screw connection systems 10/4 are supported, and their respective opposite edges 62 / o and 62 / u of the flanges 14/1, 14/2 and 14/3 of the bend 40 gaps 63 (Fig. 4d) of sufficient width remain that lateral relative movements of sufficient amount are possible without excessive lateral forces au f the studs of the Screw connection systems 10/4 act; for relative longitudinal movements, the slot 58 of the terminal flange 14/1 (Figures 4b and 4c) provides sufficient freedom of movement of the manifold 40 from the block 12.

Notwithstanding the representation of the screw connection systems 10/4 according to FIGS. 4a to 4d, their lock washers can be designed such that they also form the one block or flange-side wedge disk element of a wedge disk securing pair, which serves to prevent rotation of the nut relative to the each stud serves.

This ensures a suitable displaceability, which otherwise would have to be realized by further discs due to the material properties.

The "integrated" lock washer described above is smooth and thus slidable on its side facing away from the coupling toothing, and its securing against twisting is ensured by positive locking means, as already explained above.

Referring now to Figures 5a, 5b and 5c, a further mode of attachment to the engine block 12 of a vehicle will now be explained, again using screw fastening systems as described with reference to Figures 1 a to 3.

The manifold / engine block composite shown in FIG. 5a is functionally equivalent to the exemplary embodiment according to FIG. 4a and largely analogous in terms of construction. In contrast to the exemplary embodiment according to FIG. 4a, on the one hand the marking of a block-fixed "rotary" axis 59/5, which is marked here by the central longitudinal axis of the screw connection system 10/6 shown in FIG. 5b, is different from a structural point of view , this in Structural respect is the screw connection system 10/4 of FIG. 4d analog, as a fixed point of the element to be fastened.

In a further difference from the exemplary embodiment according to FIG. 4 a, the screw connection system 10/7 shown in FIG. 5 c is provided in the exemplary embodiment according to FIG. 5 a instead of a slot / pin combination which, in the specific case illustrated, is provided to the screw connection system 10. 2 corresponds to FIG. 2. In the case of the embodiment according to FIGS. 5a, 5b and 5c, it defines the direction in which longitudinal thermally induced changes in shape of the bend 40/5 can take place, which are subject to "transverse" dimensional changes of the flanges 14/1, 14/2 and 14 Vectorially superimpose 3, which are in amount none.

The screw connection systems shown further convey, as well as in the embodiment of FIG. 4a, only the function of hold-downs and can be identical to already explained screw connection systems 10/1, 10/2 or 10/3.

With reference also to FIGS. 5a, 5b and 5c, it should be understood that the use of reference numerals already indicated in previously explained drawing figures is intended to include the reference to these associated description parts.

The representation of FIG. 5c corresponds to the "high temperature" configuration of exhaust manifold 40/5 and engine block 12, in which the central axis 47/1 o of the screw connection system 10/7 is at its smallest distance from the right edge as shown The arrangement of the fixed point 59 and the guide convey screw connection system 10/7 and their orientation are coordinated so that the direction of the possible thermally induced Dilatation and contraction movements, to which the individual points of the bend 40/5 are subjected, span a quadrant whose coordinate origin is the fixed point 59 (FIG. 5a). For the sake of completeness, it should be mentioned that the locking washers 28 can also be used as functional elements of wedge-disk securing pairs 25 by being provided with the suitable wedge-notch embossing on the side facing the counter-disk. The type of fixation of an exhaust manifold 40 on a vehicle engine shown in FIGS. 6a to 6c is largely analogous to the one described with reference to FIGS. 4a and 5a both structurally and functionally; Accordingly, in order to avoid repetition, the indication of reference numerals in the drawing, which are not specifically mentioned in the subsequent part of the description, shall in turn contain the reference to previous parts of the description in which the elements covered by these reference symbols have already been described ,

In the case of the type of fastening of an exhaust manifold 40 on the engine block 12 of a vehicle, which is illustrated by FIGS. 6 a, 6 b and 6 c, the manifold is in its lower end corner region, as shown in FIG. 6 a, at its end facing a turbocharger, not shown "last" flange 14/3 immovably fixed by means of a screw connection system 10 / ur arranged there, such that there neither parallel to the central longitudinal axis 46 of the manifold tube 43 nor at right angles to this and perpendicular to the plane 48 / u (Fig. 4c), which is spanned by the central axes of the arranged below the manifold tube 40 screw connection systems, displacements of the local manifold end are possible.

For this purpose, there the flange opening of the mounting flange 14/3 of the manifold is formed as a circular bore whose diameter corresponds to that of a cylindrical central portion 21 / m of the threaded bolt 21 / 3u, by means of which the inner threaded portion which is engaged with a threaded bore of the engine block is set against the outer threaded portion on which the retaining nut 27 / 3u of the local threaded connection system can be screwed , This cylindrical central portion 21 / m of the threaded bolt 21 / 3u is, as seen in the mounting configuration of the manifold, completely received by the corresponding bore of the flange 14/3, wherein the axial extent of this cylindrical portion of the threaded bolt 21 / 3u substantially the thickness of the mounting flange 14/3 corresponds.

The design and arrangement of the cylindrical section 21 / m explained with reference to the threaded bolt 21 / 3u also applies to the further screw connection systems, by means of which the manifold 40 is held on the engine block 12.

By the manner of attachment of the manifold 40 so far explained, translatory degrees of freedom of movement of the manifold 40, e.g. in the direction of its central longitudinal axis and at right angles thereto, as well as to the plane marked by the central axes of the lower screw connection systems.

The possibly still conceivable rotational degree of freedom of movement about the central longitudinal axis of the screw connection system 10 / ur is excluded by a generally designated 65 "horizontal" -Führungseinrichtung, which allows only - thermally induced - length change movements of the manifold 40, whose stroke is greater is, the farther away the respective deflected manifold section is removed from the reference attachment point formed by the screw connection system 10 / ur.

This guide device 65 is in the embodiment chosen for explanation by the slot 18/1 u of the left as shown Krümmerflansches 14/1 and between longitudinal edges 19/1 o and 19/1 u of the slot 18/1 u led back and forth sliding slider 50 formed with parallel to each other flat guide surfaces 50 / o and 50 / u slidably to the upper and lower longitudinal edges of the elongated hole 18/1 is mounted and has a central bore 50 / m, whose diameter, apart from a negligible guide play, the diameter of the central cylindrical portion 21 / m of the threaded bolt 21/1 u of the screw connection system arranged there 10 / ul, which here fixes the fixation of the flange 14/1 of the bend 40 on the engine block 12.

Also for the slider 50, which surrounds the cylindrical portion 21 / m of the threaded bolt 21/1 u with sliding fit, it is true that it is taken over the entire length of the slot 18/1 u of the left Krümmerflansches 14/1, d , H. in the mounting configuration does not protrude from this slot 18/1 u. The required for the execution of thermal expansion deflections of the bend 40 lubricity of the support of the fixing nut 27/1 u and its associated Keilscheibensicherung- pair 25a / 1 u, 25b / 1 u, with which the outer threaded portion of the threaded bolt 21/1 u is in force-positive engagement, relative to the mounting flange 14/1 of the manifold 40 mediates acting as a base plate sliding rod, which between the Schraubbefesti- system 10 / ul provided with the horizontal guide mounting flange 14/1 of the manifold 40 and the lower Schraubbefestigungssys- system 10 / um extends, by means of which the sliding rod 66 is translationally immovably fixed to the central mounting flange 14/2 of the manifold 40.

The slide rod 66 is provided in the region of the guide device 65 with a slot designated overall by 67, the upper longitudinal edge 67 / o and the lower longitudinal edge 67 / u parallel to the longitudinal edges 19 / lo and 19 / lu of the elongated hole 18/1 u of the mounting flange 14/1 are lost, which is held by the screw fastening system 10 / ul on the engine block 12.

With the parallel longitudinal edges 67 / o and 67 / u of the slot 67 is a flat "guide rib" 68 of the lock washer 28 / lu of the left lower screw connection system 10 / ul in positive-slidable engagement, the circular disc-shaped body outside, ie at the side facing away from the mounting flange 14/1 is supported on the slide bar 66. This lock washer is provided with a central, circular opening, which in the mounting configuration is arranged coaxially with the corresponding openings of the disks of the wedge disk securing pair, through which the external thread section the threaded bolt 21/1 u passes, to which the fixing nut 27/1 u can be screwed, the purpose of proper tuning of the wedge angle of the wedge discs 25a / lu and 25b / lu and the thread pitches of the bolt 21 / lu, seen in the mounting configuration, rotatably with the bolt 21 / lu is connected, thus, due to the Verdrehsiche tion, which is achieved by the engagement of the lock washer 28 with the slot 67, a total of d. H. Also, not in the anchoring thread of the engine block is rotatable and therefore the screw 12 / ul is secured against loosening.

It is understood that the measured from the contact surface of the lock washer 28 height of its guide rib 68 is slightly smaller than the thickness of the slide rod 66, but this almost corresponds.

With respect to the screw connection system 10 / ul with regard to the possibility of thermally induced relative movements between the manifold and engine block on the one hand, and on the other hand carried out for security against loosening of the connection applies mutatis mutandis to the screw connection systems 10 / ol and 10 / or, by means of which a functionally "upper" sliding rod 69 corresponding to the sliding rod 66 with the left mounting flange 14/1 and the right mounting flange 14/3 of the manifold of the is connected, that longitudinal, ie directed parallel to the longitudinal axis 46 of the manifold relative movements between the manifold and the vehicle block are possible without leading to overuse of the bolts of the upper Schraubbefestigungssysteme 10 / ol, 10 / om and 10 / or.

The upper slide bar 69 is formed symmetrically with respect to the central axis of the central screw connection system 10 / om in the illustrative, special arrangement example, which, analogous to the screw connection systems 10 / ur and 10 /, has a fixed connection against the longitudinal deflections Engine block mediated.

In the case of the upper screw connection systems 10/10 / om and 10 / or, which essentially only provide the function of hold-downs, however, it is necessary to have the slot openings 18/1 o and 18 / 3o and also the round opening 18 / 2o of the upper slide rod 69, through which each of the threaded bolts 21/1 o, 21 / 2o and 21 / 3o pass, transverse to the direction of the marked by the central axes of the "lower" screw-connection systems level and extending in this bolt axes to give it sufficient clearance that in the said transverse direction thermal dimensional change of the manifold flanges do not lead to a significant load on the threaded bolts of the screw connection systems.

Claims

claims

1 . Screw connection system (10/1, 10/2, 10/3) for attaching a machine element (1 1; 40) to a block-shaped support, for. B. an exhaust manifold (40) on the engine block (12) of an internal combustion engine, with at least one in a threaded bore (22) of the block (12) screwed threaded bolt (21) passing through an opening of a flange of the machine element to be fixed, outer threaded portion (24 / a) onto which a threaded nut (27) serving to fix the machine element can be screwed, which in the assembly configuration of the system is secured against detachment from the threaded bolt, characterized in that the threaded bolt (21) between the inner threaded portion (24 / i) and the outer threaded portion (24 / a), a securing portion (23) serving to secure against twisting becomes more angular

Has outer contour, in the mounting configuration with the at least partially complementary to the contour of the securing portion (23) shaped edge of an opening of a non-rotatably connected to the machine element fuse element (28) or a functionally corresponding opening (18 / o; 18 / u) the machine element itself is in positive engagement.

2. Screw connection system according to claim 1, characterized in that the edged fixing portion of the threaded bolt (21) is designed as a short square profile piece with opposite profile end faces, at parallel longitudinal edges (19 / o and 19 / u) opposite each other lying slots (18 / g and 18 / u) of the mounting flange (14) of the body to be fastened (1 1) is displaceably guided.

3. screw connection system according to claim 1, characterized in that for the rotationally fixed fixation of the threaded bolt (21/3) a centre- The center section (23/3) is provided with an outer toothing with longitudinally extending tooth ribs, which is in meshing engagement with an internal toothing (34) of complementary clear cross section of a locking disc (28/3), which in the tightened state of the fixing nut (27) in held this fixation configuration.

Screw connection system according to claim 1 or claim 2, characterized in that the means for securing the threaded bolt (21) comprises a in the assembly configuration in abutment with the machine element (1 1; 40) held lock washer (28/1; 28/2), the secured by positive engagement of stop elements (29 / I, 29 / r; 31) on counter surfaces (19 / o, 19 / u; 33) against rotation about the central axis (27) of the system (10/1; 10/2) is (Figures 1 and 2).

Screw connection system according to claim 4, characterized in that the securing disc also conveys the function of a wedge disc of a wedge disc securing pair (25) facing the machine element (1 1, 40) facing it.

Device for fixing a machine element, which is exposed to operating temperatures, on a machine block whose operating temperature is comparatively low, eg an exhaust manifold (40), on the cooled block (12) of an internal combustion engine, using a plurality of screw connection systems according to one of claims 1 to 5 which, acting on fastening flanges (14/1, 14/2, 14/3) of the elbow (40), hold it with a minimum force in contact with counter surfaces of the block (12), wherein at least two screw connection systems are provided per flange, characterized in that the manifold is held non-displaceable at a reference point (59) of the block (12), for example by form-locking engagement of a block-side and a flange-side engagement element, and a guide device (65) is provided, by which the direction of thermally induced Elongationsbewegungen the manifold (40) relative to the block (12) and relative to the flanges in abutment with the block holding elements of the screw connection systems is determined (Fig. 4a, 5a and 6a).

Fixing device according to claim 6, characterized in that for a pointwise fixing of the manifold (40) and to a unidirectional guide thermally induced deflection movements of the manifold bend-resistant and block-resistant, positively acting engagement elements are provided, and that the screw connection systems are designed as hold-down, to the Flanges (14/1, 14/2, 14/3) of the manifold (40) attacking, are displaced relative to this guided.

Fixing device according to claim 6 or claim 7, characterized in that at least some of the screw connection systems penetrated by their threaded bolt, directly on the flanges directly slidably supported locking washers (28) which are guided in the same direction slidably on block-fixed guide elements.

Fixing device according to one of claims 6 to 8, characterized in that the fixing point is marked by the central axis (59) of a screw connection system used for fixing (10 / ur) that the guide means (65) in a slot (18/1 u ), preferably of the fixation point farthest Krümmerflansches (14/1) displaceably guided by the threaded bolt (21/1 u) of the local screw connection system (10 / ul) interspersed slider (50) by almost, the oppositely arranged sliding surfaces (50 / o and 50 / u) abuts the long-hole cheeks (19 / o and 19 / u), and that the central axis (59) of the fixing screw connection system (10 / ur) in the parallel to the long Hollow cheeks extending longitudinal center plane of the guide slot (18 / lu) runs.

Fixing device according to Claim 9, characterized in that at least one slide rod (66; 69) is provided which, in the region of a screw connection system (10/10; 10/10; or), is subjected to the thermally induced displacements of a manifold flange relative to the block (10; 12), a suitable lubricity mediated for this purpose and provided there in each case with a slot (67) whose mutually parallel longitudinal edges also parallel to the longitudinal edges of the local screw connection system (10 / ul; 10 / ol; 10 / or) associated flange slot (18/1 u; 18/1 o; 18 / 3o) and that the lock washer (28/1 u; 28/1 o; 28) of the respective screw connection system (10 / ul; 10 / ol; 10 / or) with its guide rib (68) at the longitudinal edges of the slide rod (66; 69) is guided.