WO2000050717A2

WO2000050717A2 - Motor vehicle door brake with holding function

Info

Publication number: WO2000050717A2
Application number: PCT/DE2000/000512
Authority: WO
Inventors: Nils Magnus; Lothar Brückner
Original assignee: ED. SCHARWäCHTER GMBH
Priority date: 1999-02-22
Filing date: 2000-02-22
Publication date: 2000-08-31
Also published as: DE19907455A1; AU3655100A; DE20022548U1; DE20022547U1; DE50000602D1; EP1155211B1; DE10080437D2; EP1155211A2; WO2000050717A3

Abstract

The invention relates to a door brake pertaining to a motor vehicle, said brake having a holding function and comprising a closed sleeve component (2) made of metallic material. The sleeve part (2) can be fixed to one of the door assembly parts: door and door post. The door brake also comprises a shaft component (1) that engages with the sleeve component (2) and that consists of a solid metallic material. The shaft component (1) can be fixed to the other door assembly part. The cross-section of the shaft component (1) is provided with a curvature that deviates from the elemental circle form when the shaft component (1) is joined to a complementary embodiment of the shape of the cross-section of the borehole pertaining to the sleeve component (2), whereby the curvature extends over at least a part of the length of the shaft component (1), the length matching the height of the sleeve. The aim of the invention is to create a motor vehicle door brake that is provided with a defined break power at a predetermined door opening angle and that can be produced in a simple manner. The aim of the invention is also to provide structural parts of said door brake, whereby said structural parts have a stress distribution which is as favourable as possible during braking due to elastic changes in the form. To this end, the shape of the cross-section belonging to the shaft component (1) and the sleeve component (2) is convex over the entire circumference thereof. The maximum extension of the shape of the cross-section belonging to the shaft component (1) exceeds the minimal extension of the shape of the cross-section belonging to the sleeve component (2). The braking effect is obtained by an elastic change in the form of the shaft component (1) and the sleeve component (2).

Description

Motor vehicle door brake with holding function

The invention relates to a motor vehicle door brake according to the preamble of claim 1 with a holding function, comprising a closed sleeve part made of metallic material that can be connected to one of the door arrangement parts door and door spar, and a shaft part engaging in the sleeve part made of a solid material of metallic material that with the other Door arrangement part is connectable, wherein the shaft part in connection with a complementary design of the cross-sectional shape of the bore of the sleeve part has at least over part of its length corresponding to the sleeve height a rounding course of its cross-section that deviates from the pure circular shape.

DE-A-44 06 824 describes a motor vehicle door hinge with an integrated brake, in which the hinge pin is used as the inner part and a hinge eye bore in the trade of one of the two hinge halves as the outer part of the brake. The hinge pin is secured against rotation in the other of the two hinge halves, so that the inner part and outer part of the brake can be fixed to corresponding door arrangement parts via the hinge halves. The inner part is equipped with at least one radially rising wedge surface, this is also assigned a radially rising wedge surface on the inner part, the two wedge surfaces having to have the same slope in order to form wedge surface pairs which lie essentially flat against one another over their entire area of coverage. The braking effect is brought about by the mutual friction and thus the elastic deformation in the area of the wedge surfaces. An important feature of this known door brake is that the wedge surfaces may only extend over part of the circumference of the hinge pin and hinge eye bore and on the one hand have a very gently rising wedge surface and on the other hand immediately have a steeply falling flank surface in order to join the hinge enable. This initially results in a Considerable manufacturing effort both for the hinge pin and for the hinge eye hole, because the interacting wedge surfaces on the one hand on the hinge pin and on the other hand on the inner circumference of the hinge eye hole must be manufactured with great precision, on the one hand to achieve a sufficient inhibitory effect and on the other hand, premature wear and adverse consequences of environmental influences to exclude. Furthermore, it is not possible to achieve a braking or holding effect that remains constant over a sufficient opening angle range of a door. Another disadvantage is that the measurement of the inner part and outer part is complex, so that the formation of pairings that meet predetermined tolerances is hardly possible. In addition, there are discontinuous transitions in the area of the transitions from wedge surface to flank surface and from wedge surface to the next wedge surface or a neutral section, which tend to plastic shape changes due to material flow during load peaks, e.g. when loads such as children act on the door in addition to the pivoting movement, and thus the disadvantageously change the preset forces.

DE-A-196 00 063 describes a motor vehicle door brake which is structurally combined with a door hinge and in which the inner part of the brake is fixed in a rotationally secure manner on one door arrangement part by means of one hinge half and the outer part is fixed on the other door arrangement part by means of the other hinge half, and furthermore the inner part of the brake is formed by a length section of the hinge pin and the outer part of the brake either directly by the hinge eye of the other hinge half or by a sleeve-shaped extension connected to the hinge eye. In the known motor vehicle door brake, the hinge pin, in conjunction with a complementary design of the hinge eye bore of at least one hinge eye of the hinge half whose hinge eyes he passes through with bearing play, has a rounding curve deviating from the pure circular shape over at least part of his or her length ranges assigned to one or each of these hinge eyes its cross-section in such a way that the amount of the greatest deviation of the rounding course from the The circular shape of both the hinge eye bore and the hinge pin cross-section is of the order of magnitude of a desired rounding error and is therefore approximately in the range from less than a tenth to less than a hundredth of the general hinge pin diameter. A pairing of really complementary parts is hardly possible, and a change in the phase of the curve of the braking force via the opening angle of the door can hardly be influenced. A constant braking and holding effect over a predeterminable door opening area cannot be achieved with this type of motor vehicle door brake. The known motor vehicle door brake also has no symmetrical or deliberately convex cross-sectional shape.

DE-U-76 16 362 shows a furniture hinge in which braking of the furniture parts struck on the two hinge halves is achieved in that the hinge pin has an oval cross-sectional shape in that length range in which it passes through the hinge eye of the associated other hinge part is held clampingly in the hinge eye bore, which is also of oval design, in that a slot in the hinge eye is widened by the rotary movement of the hinge pin and a pretension is thereby generated, with which the hinge pin is gripped. A disadvantage of this configuration is, in particular, the contamination-intensive slitting of the hinge eye, which must also accommodate the entire elastic change in shape of the shaft / sleeve system. Accordingly, only relatively small braking forces can be generated according to this concept, which may be sufficient for a furniture hinge, but are not suitable for absorbing the weight of a motor vehicle door and the moments that act on it.

US-A-3,000,049 describes a plastic hinge which has a hinge pin stub which is formed in one piece with one trade and has radially projecting webs which are assigned corresponding groove recesses in the hinge eye of the other hinge part. Such a plastic hinge is not suitable per se, the loads and moments that arise act a motor vehicle door to record, in particular the braking forces with small oversizes due to an elastic change in shape of one and / or the other part so low that they do not lead to a significant braking, especially not to a corresponding continuous braking of the hinge.

EP-A-0 255 879 describes a motor vehicle door hinge in which a hinge pin, which is held in one hinge half in a rotationally fixed manner, is mounted with a running seat in the hinge eye bore of the other hinge half and is designed with radially arranged projections in this area, which has a profile contour jointly define a braking characteristic for the hinge eye bore. A disadvantage of the known motor vehicle door hinge is, on the one hand, the complex manufacture of the hinge pin and the hinge eye bore associated with its profile, which generally requires a separate sleeve. In addition, the projecting webs of the hinge pin are particularly at risk of stress at peak loads for a plastic shape change, which is why the counter contour of the hinge eye requires a very complex and difficult to manufacture counter shape. A significant further disadvantage of the known motor vehicle door hinge is that the contour of the hinge pin can hardly be described mathematically, with the result that when selecting the material, a substantial overdimensioning of the strength compared to a contour which can be represented as a model by the finite element method is to be selected is. In addition, the known motor vehicle door hinge then does not have an axially freely assembled shaft / sleeve combination, with the result that considerable effort is required to assemble and disassemble such a hinge.

It is the object of the invention to provide a motor vehicle door brake according to the preamble of claim 1, which has a defined braking force with simple manufacture at least over a predetermined door opening angle and, moreover, the best possible voltage distribution in its components during braking due to has elastic changes in shape. Furthermore, a mathematically controllable representation should be given as a model.

This object is achieved in the motor vehicle door brake mentioned at the outset with the characterizing features of claim 1 in that the cross-sectional shape of the shaft part and the sleeve part is convex over their entire circumference, that the maximum extension of the cross-sectional shape of the shaft part exceeds the minimum extension of the cross-sectional shape of the sleeve part , and that the braking effect is brought about by an elastic change in shape of the shaft part and sleeve part.

The motor vehicle door brake according to the invention is convex over the entire outer circumference of the shaft part and over the entire inner circumference of the sleeve part, i.e. that a tangent to the contour does not intersect the contour at another point. It is therefore a really convex contour that is free of concave indentations or also avoids flattening, as occurs, for example, with oval or cut cylinders. The genuinely convex design of a shaft part made of solid material allows a particularly favorable stress distribution and in the event of elastic deformation, notch stresses on edges as a result of the notch effect are avoided. In addition, this recess-free, closed contour allows simple measurement with probing or optical measuring instruments and, in terms of manufacturing technology, external grinding and hardening. Due to the favorable, continuously running contour, it is possible to measure a shaft part with a few measuring points or to use it as a mathematical model in a computer-aided design or production planning. In addition to the advantages in terms of production technology, the contour allows, in particular, a mathematical calculation of the elastic changes in shape of two correspondingly shaped parts of the motor vehicle door brake, so that, with knowledge of the modulus of elasticity and the yield limits, materials can also be used for local maximum loads, so that a material pairing can be carried out in a reliable and reproducible manner and appropriate dimensioning of the components are selected with which continuous operation is possible at the cheapest cost.

The motor vehicle door brake according to the invention effects braking by mutual relative rotation of the shaft part and the sleeve part, the maximum extent of the cross-sectional shape of the shaft part in the area of the brake exceeding the minimum extent of the cross-sectional shape of the sleeve part, so that an excess or a theoretical overlap dimension exists in certain angular positions . Due to the mathematically controllable convex contour of the parts, this overlap can advantageously be calculated for each angular position, whereby the modeling of a section of the two parts can be sufficient due to the symmetrical design. When the shaft part and sleeve part are pivoted relative to one another, an elastic change in shape of the shaft part and sleeve part will occur in the areas in which there is a theoretical overlap, the force to be applied for the elastic change in shape causing the braking effect. Since the change in shape is only elastic, no swiveling in or the like is required for the first time, and the change in shape of the two parts is completely reversible. As a result, the braking forces acting on the motor vehicle door brake can be predetermined precisely and reproducibly by selecting the dimensions of the two parts.

The motor vehicle door brake according to the invention can either be structurally combined with a door hinge or can be used independently of the door hinges, the braking force curve over the door opening angle being extremely precisely adjustable due to the reproducible setting of the mutual position of complementary shaft part and sleeve part. The invention makes it possible, with little technical effort, to create a motor vehicle door brake which operates permanently without noise and can be designed to be small in size with a high level of durability.

Advantageously, at least one and preferably both parts of the shaft part and sleeve part have an elliptical cross section, the distance the focal axes of the ellipses can be provided close to one another, which gives a very close approximation to the circular cylinder shape. The elliptical cross-sectional shape is convex over its entire circumference, as a result of which stress peaks at the contact points of the shaft part and sleeve part and in particular the occurrence of notch stresses are reduced as far as possible. The cross-sectional dimensions of the shaft part and the sleeve part are selected such that, with aligned large elliptical axes, an axial mutual displacement without braking effect and thus without elastic change in shape of one of the two parts is possible. This axial play can be increased or decreased by different temperatures and the thermal expansion induced thereby, while in use the temperature of the two parts will generally be the same. It is expedient in the case of an elliptical cross-sectional shape of the shaft part and the sleeve part that the large ellipse axis of the shaft part is larger than the small ellipse axis of the sleeve part, while the large ellipse axis of the sleeve part is larger than the large ellipse axis of the shaft part and the small ellipse axis of the shaft part is larger than that small axis of the sleeve part. When the two parts are aligned, this results in a braking force of 0, which initially increases and then decreases again depending on the mutual rotation of the shaft part and sleeve part until the two parts are aligned again, that is, the phase of the braking force can run according to the angle of rotation between the two large ellipse axes.

The amount of braking force can be adjusted by selecting the play between the shaft part and the sleeve part. In addition to the difference (play) between the large ellipse axes, there can also be a different difference (play) between the small ellipse axes by means of which the braking force can be adjusted.

Preferably, in order to ensure permanent functioning of the ellipse mechanics, the overlap dimension U _d , which is the difference between the large ellipse axis a _{s of} the shaft part and the small ellipse axis b _k des Defined sleeve part, smaller than a multiple of the average inner diameter of both ellipses, which is a quarter of the added large and small ellipse axes of the shaft part (a _s or aι _< ) and sleeve part (b _s or bk). The average inside diameter d can be calculated according to the following formula:

resulting in an inequality that the coverage U _e ι must satisfy according to the following formula:

U ,, = α- - ό, ^• <5.70 x LCT ³ d.

where d _{a is} the mean outer diameter of the sleeve part. The overlap dimension U _e ι corresponds to the length that must be elastically spent by changing the shape of the two parts for the purpose of mutual displacement. For an appropriate application in a motor vehicle door, the average outside diameter is expediently less than 30 mm, preferably less than 25 mm and particularly advantageously between 16 and 22 mm, a value of between 18 and 20 mm having proven particularly advantageous.

The outer cross section of the sleeve part can deviate from the purely circular shape as a cross-sectional shape and, in particular in the area of the stress-intensive small ellipse axis of the sleeve part, can be formed with an increased thickness. This results in a better voltage distribution, which significantly extends the life of the motor vehicle door brake. If the sleeve part and the shaft part are formed with an elliptical cross-section, they expediently differ only slightly from the pure circular shape, so that preferably the distance between the focal points of the sleeve part and the shaft part from the axis of rotation is less than 5%, preferably less than 1% of the respective major ellipse axis. This shape is particularly favorable both for the production of the sleeve and of the shaft part, since only a part of the bore or the shaft has to be reworked compared to the production of a cylindrical part.

According to a further preferred embodiment, an increasing braking or inhibiting force can be achieved over at least one predetermined opening angle and an at least substantially constant braking or inhibiting force can be achieved over a further likewise predeterminable door opening angle range.

When utilizing the material deformation within the range of elastic deformability of a material in order to achieve a braking or holding force, a braking or holding force that remains constant over a predeterminable angle of rotation range also ensures a braking or holding force that remains constant over this angle of rotation range. With a suitable design, a very high fatigue strength can also be achieved within the framework of such a design of a motor vehicle door brake. Here, at least in principle, different possibilities are available for achieving a deformation resistance that remains constant over a predeterminable angle of rotation range.

In view of the further possibility of generating rising and / or falling deformation resistances over a predetermined total rotation angle range of the brake outside the rotation angle range characterized by a constant deformation resistance, a first, simple embodiment of the invention provides that this Wave part regarding of a region of the cross-sectional shape of its body which does not deviate from the circular shape has a play with respect to the cross-sectional shape of the sleeve part, and that the shaft part is provided with at least one shape which is radially oriented with respect to its general circumferential profile and forms a projection.

The amount of the projection of the at least one radially directed shape of the shaft part is greater than the maximum play between the course of the outer circumference of the area of the cross-sectional shape of the shaft part that does not deviate from the circular shape and the course of the inner circumference of the area of the cross-sectional shape that does not deviate from the circular shape of the sleeve part.

A region upstream of the rotation angle range characterized by a constant deformation resistance, at least in the door opening direction, with an increase from zero to the constant deformation resistance and dependent on the direction of rotation

Reversal of the direction of rotation correspondingly falling deformation resistance can be achieved with simultaneous determination of a pivoting state of the brake assigned to the door closing position in that the at least one radially directed projection of the shaft part is the closed position of the

Motor vehicle door marking and complementary shaped, concave

Recess is assigned in the inner circumference of the sleeve part, wherein constructive means are expediently taken in order to achieve or ensure, in particular, a continuously increasing resistance to deformation.

In an expedient constructive design, it is provided that the area of rotation, between the shaft part and the sleeve part, which has a constant deformation resistance, viewed in the door opening direction, has a region with a continuously increasing deformation resistance due to the dome-shaped one assigned to the at least one radial projection of the shaft part Recess is formed in the inner circumference of the sleeve part.

The rotation angle range, which is characterized by a constant deformation resistance, is further followed, at least in the door opening direction, by a rotation angle range which acts as a limitation of the total opening angle of the door with a strongly increasing deformation resistance, which is preferably accomplished by the fact that the rotation angle range, which has a constant deformation resistance, is seen in the door opening direction Area with a continuously increasing resistance to deformation is formed by a flattening in the inner diameter of the sleeve part which reduces the play between the white part and the sleeve part.

A symmetrical design of the shaft part and sleeve part is expediently provided, which is characterized in that the shaft part is provided with two mutually opposing formations, the general circumferential course of which forms a radially directed projection, each of which is one of two likewise opposite one another in the inner circumference of the Shaped sleeve part is assigned to concave recesses marking the closed position of the motor vehicle door and that on the inner circumference of the sleeve part two flats which reduce the play between the shaft part and the sleeve part are also arranged opposite one another.

Particularly expedient constructive designs of the two parts of the motor vehicle door brake are seen in the fact that the radially directed projections on the shaft part have a circular segment shape in cross section, the radius of the circular segment shape corresponding to a fraction of the diameter of the body of the shaft part in its area not deviating from the circular shape, whereby the radius of the circular segment shape of the radially directed projections on the shaft part lies in the range between 10 and 50% of the diameter of the region of the body of the shaft part which does not deviate from the circular shape. Complementary to this, it is then provided that the concave recesses complementary to the radially directed projections on the shaft part have a circular segment shape in the inner circumference of the sleeve part, the radius of the circular segment shape in the range between 10 and 50% of the diameter of the area of the sleeve part which does not deviate from the circular shape lies.

Furthermore, it is then considered advantageous that the play between the area of the body of the shaft part that does not deviate from the circular shape and the area of the sleeve part that does not deviate from the circular shape is in a range between 5 and 0.15% of the diameter of the body of the shaft part , in which case it can further be provided that at the same time the height of the elevation of the radially directed projections of the shaft part lies in a range between 5 and 25% of the diameter of the body of the shaft part. The transitions of the radially directed projections on the shaft part into the general circumference of the shaft part can be designed with a radius of up to 300 mm.

According to yet another preferred embodiment, at least one and preferably both of the shaft part and the sleeve part is formed with a tricycloidal cross section, the corners of the tricycloids of the shaft part and sleeve part preferably having the same or almost the same curvature, and the distance of the corner of the tricycloid from their center at Shaft part is slightly less than the sleeve part. It is possible here to choose a bulge in the sleeve part somewhat larger than that in the shaft part, which leads to a degressive increase in the braking effect, or alternatively to select a bulge somewhat steeper, which allows a progressive increase in the braking force.

If the two tricycloid cross sections are exactly aligned with one another, the white part can expediently be pulled out of the sleeve part without an elastic change in shape of the two parts, whereby the assembly is possible in a simple manner. According to the typical characteristic of a tricycloid, a phase of a braking course is approximately one third of the circumference of a circle and thus 120 °. Over this braking course, an increasing and approximately decreasing braking force is achieved over the opening angle, so that when using a conventional opening angle of approx. 75 ° with a motor vehicle door, the majority of the pivoting movement can be formed with a progressive, stepless increase in the braking force . Due to a starting position reflecting the closed door position, which is adjusted by an angle of rotation relative to an aligned position, which can differ both negatively and positively from the aligned position - viewed in the opening direction 4 - a phase shift of the braking force curve can be set via the opening angle in such a way that the A braking force corresponding to a zero position is either reached during aligned opening and a stop position is marked, or is not reached during opening, as would be the case with an angle of rotation of a few degrees (positive).

The motor vehicle door brake according to the invention can be detached from a motor vehicle hinge with the corresponding door arrangement parts, which enables a spatially separate arrangement. Expediently, however, the motor vehicle door brake according to the invention will be physically connected to a door hinge of the motor vehicle, both a single-joint hinge and a multi-joint hinge basically being considered for this purpose. The hinge pin is then the shaft part and a hinge eye is the sleeve part. In this case, preferably not only a section of the hinge pin is designed according to the invention, but rather the entire area passing through the hinge eye.

In general, it can then also be provided that the shaft part and / or the sleeve part are coated with a hard material layer selected from the group comprising carbides, nitrides, carbonitrides and borides. Further features and advantages of the invention emerge from the subclaims and from the description below.

The invention is explained below with reference to the accompanying drawings using preferred exemplary embodiments.

1 shows a force / angle of rotation diagram representation of the desired and achieved braking and inhibiting force curve of a motor vehicle door brake according to the invention.

Fig. 2 shows a schematic section through a first embodiment of a motor vehicle door brake according to the invention.

Fig. 3 shows a detail of Fig. 2 on an enlarged scale.

4 shows a second exemplary embodiment of a motor vehicle door brake according to the invention on a scale of approximately 5: 1.

FIG. 5 shows a schematic exaggerated representation of the motor vehicle door brake from FIG. 4 in an aligned position.

FIG. 6 shows the motor vehicle door brake from FIG. 5 at an angle of rotation of 90 °.

7 shows a schematic section through a third exemplary embodiment of a motor vehicle door brake according to the invention.

In the force-angle of rotation diagram shown in FIG. 1, several different braking force profiles are plotted, each over an angle of rotation range of 90 °, the braking force profile shown in dashed lines with crosses corresponding to that braking force profile which can be achieved by the second exemplary embodiment and wherein the one in a solid line The braking force curve shown corresponds to the braking force curve which can be reached in the first exemplary embodiment.

This achieves a braking force curve which follows a braking force increase lying in the door opening direction and remains essentially constant over the further usable door opening angle and in which a renewed braking force increase only begins towards the end of the overall permitted door opening angle. by means of a design of a motor vehicle door brake shown schematically in FIG. 2. In this illustration, 1 denotes the shaft part and 2 the sleeve part of a door brake consisting of only two parts. In the embodiment shown, the shaft part 1 and the sleeve part 2 are each designed symmetrically and, first, the shaft part 1 has two mutually oppositely arranged formations forming a radially directed projection 3 outside two circumferential regions 1a and 1b which are formed opposite one another and do not deviate from the circular shape. Complementary to this, the sleeve part 2, outside of its circumferential regions 2a to 2d that do not deviate from the circular shape, is equipped with two concave recesses 4 arranged opposite one another in its inner circumference. Furthermore, the sleeve part 2 is equipped with two flats 5 of its inner circumference which are arranged opposite one another and the concave recesses 4 are arranged offset by 90 ° in each case, and which flatten the circumferential regions 1 a and 1 b of the shaft part 1 and 2a to 2d that do not deviate from the circular shape the game 6 provided at least partially bridge the sleeve part.

The radially directed projections 3 on the shaft part 1 have a circular segment shape in cross section, the radius RS1 of the circular segment shape being in the range between 10 and 50% of the diameter of the area of the body of the shaft part 1 which does not deviate from the circular shape, and the mutual distance AS1 of the two radially directed projections 3 in the range between 5 and 100% of twice the diameter of the diameter of the region 1 a - 1 b of the body not deviating from the circular shape Shaft part 1 is. The radius RH 1 of the concave recesses 4, which are complementary to the segment-shaped, radially directed projections 3 on the shaft part 1, in the inner circumference of the sleeve part 2 is in the range between 10 and 50% of the diameter of the region 2a to 2d of the sleeve part 2 that does not deviate from the circular shape.

The play 6 between the area of the body of the shaft part 1 which does not deviate from the circular shape and the area of the sleeve part 2 which likewise does not deviate from the circular shape lies in a range between 5 and 0.15% of the diameter of the body of the shaft part 1. The inside width of the sleeve part 2 in the region of the opposing flats 5 of its inner circumference lies in a region between the full diameter of the body of the shaft part 1 and the full diameter of the inside width of the sleeve part 2 in the region of its regions 2a to 2d which do not deviate from the circular shape. The transitions of the radially directed projections on the shaft part into the general circumference of the shaft part can be designed with a radius RS2 of 0 to 300 mm. The range of the radii of the circle segments is chosen so that the existing geometry changes into an oval construction.

In the embodiment shown, the actual diameter of the non-circular area of the body of the shaft part 1 is 9.8 mm and the diameter of the non-circular peripheral areas 2a to 2d of the sleeve part is 10mm, while the diameter of the sleeve part 2 is in the area of its two Flattenings 5 is reduced to an amount of 9.9 mm. The distance between the centers of the circles of the segment shapes forming the radially directed projections 3 of the shaft part 1 is 4.2 mm.

4, the shaft part 1 has an elliptical outer contour, and the sleeve part 2 receiving the shaft part has an likewise elliptical inner contour. The large ellipse axis of the shaft part 1 is 10.19 mm, and the large ellipse axis of the sleeve part 2 is 10.26 mm. The two large ellipse axes coincide with the axis 20 indicated vertically in FIG. 4. The small ellipse axis of the shaft part 1 has a length of 10.03 mm, while the small ellipse axis of the sleeve part 2 has a length of 10.1 mm. The two small ellipse axes coincide with the axis 21 shown horizontally in FIG. 4. If one adds up the four mentioned axis lengths and divides them by four, one obtains an average inner diameter of the motor vehicle door brake of 10.145 mm. The correspondingly determined average outer diameter of the shaft part 2 is 18.5 mm.

It is found that in the aligned arrangement of the sleeve part 2 and the shaft part 1 shown in FIG. 4, an axial mutual displacement of the two parts is possible since the sleeve part 2 has an oversize at any point on the circumference of the shaft part 1. In contrast, the large ellipse axis of the shaft part 1 is larger than the small ellipse axis of the sleeve part 2, so that when the two parts and thus their large ellipse axes are rotated relative to each other in the region of the end faces forming the ends of the large ellipse axis of the shaft part 1, the two parts abut and one another Define oversize. Since the two parts in the present case are made of a metallic material such as steel, the two parts have an elastic deformability due to their modulus of elasticity, which enables mutual rotation when appropriate forces or moments are applied, the deforming energy being applied as braking energy when the door is pivoted is. This results in an elastic change in the shape of the ellipse of both the shaft part 1 and the sleeve part 2, the braking force to be applied increasing with increasing angle of rotation of the two large hinge axes and reaching a maximum at an angle of rotation of 90 °. The theoretical considerations for this are explained in more detail below with reference to a strongly exaggerated model in FIGS. 5 and 6.

5 and 6, a _s denotes the large hinge axis of the shaft part 1, a _k the large hinge axis of the sleeve part 2, b _s the small one The hinge axis of the shaft part 1 and b _k the small hinge axis of the sleeve part 2. Also shown in dash-dotted lines are the average inside diameter of the shaft-sleeve system dj, which results from the following formula:

This simple formula allows a reliable approximation, since the contour of the ellipse is continuous and therefore easy to integrate.

It is understood that the cross-sectional area of the shaft part 1 must not exceed the cross-sectional area of the imaginary circle with diameter d, and that the cross-sectional area of the ellipse of the sleeve part 2 must exceed the area of the circle with diameter d, so that there is no full-surface friction of the two Parts occur when mutually twisted. Nevertheless, the two parts, as can be determined in the calculation on the basis of the dimensions indicated in FIG. 4, are relatively closely approximated to one another.

5 corresponds to the aligned position of the two ellipses, as already shown in FIG. 4, in which an axial displacement or assembly of the two parts is possible without braking action. 6, the shaft part 1 is rotated by an angle of 90 ° with respect to the sleeve part 2, so that the maximum braking force is reached.

6 shows that without changing the shape of the two parts this position would not be assumed, since there is an overlap of the shaft part 1 with respect to the sleeve part 2 of a total of u _e ι, each half on each of the two end faces at the end of long axis of the ellipse a _k of the shaft portion 1 via the short axis of the ellipse b _k of the sleeve member 2 is made. It goes without saying that the overlap dimension u _e ι is maximum in the illustration according to FIG. 6, but varies with each other depending on the angle of rotation of the two large ellipse axes a _k , a _s . The force applied as a function of the angle of rotation is proportional to this dimension (or its square).

Since the overlap dimension U _e ι is converted into an elastic change in shape of the two parts, a functioning brake also requires consideration of the material of the sleeve which surrounds its bore, since the elastic deformation behavior changes as a function of the material thickness. To this end, it can be assumed in a simplified manner that the sleeve is also circular-cylindrical and has an average outer diameter d _a , the material of the sleeve filling the ring, which is delimited by di and d _a . In reality, the outer contour of the sleeve 2 is approximated to an octocycloid, that is to say to an octagon with rounded corners, the areas between the rounded corners also being able to be completely flattened for production reasons, but not necessarily. This results in material protrusions at the four corners of the octocycloid compared to the calculated circular shape d _a , while relatively thin-walled sections are provided in the areas in between. The thicker-walled areas of the outer circumference of the sleeve part 2 are aligned with the axes which define the small and the large ellipse axes a _k and b _{k of} the sleeve part, since here the ring thickness is to be increased or the tension maximum when the shaft part is rotated by 90 °, as in FIG 6 shown.

Based on the above definition, there is a critical coverage dimension u _e ι that must not be exceeded in order to ensure permanent functioning of the ellipse mechanics:

The inequality for the maximum overlap dimension u _e ι has been analyzed in accordance with the calculation of cross-compression connections of cylindrical clamping parts with good agreement with empirical tests.

The above embodiment of a motor vehicle door brake can be integrated particularly advantageously into a motor vehicle door hinge, the shaft part 1 being formed by the section of a hinge pin and the sleeve part 2 by the hinge eye of the hinge half in which the hinge pin is held with a sliding seat. The remaining section of the hinge pin 1 would then be held firmly in a hinge eye of the other hinge half, wherein the entire hinge pin can be designed as an ellipse and for

Holding the hinge pin in the other hinge half of this hinge is either formed circumferentially with a knurl or other means for non-rotatably holding the hinge pin or the hinge eye is such a tight press fit that it turns the hinge pin in the other even when the loads on the motor vehicle brake occur

Hinge eye is excluded.

Since the parts 1, 2 are made of metal and preferably of steel and are only subjected to elastic loads, the braking forces are permanently reproducibly ensured, so that use in vehicle technology is expedient.

The connection of shaft part 1 and sleeve part 2 takes place in use via a form-fitting, removable connection.

The motor vehicle door brake shown in FIG. 7 differs from the previous exemplary embodiment in that the shaft part and the sleeve part have a tricycloidal cross section. The braking effect resulting from the relative rotation has a phase of only 120 °, and the adjustable braking forces may be greater. In the case of a tricycloid cross-section, the same calculations apply for the braking forces as for the elliptical cross-sections, with the mean inner or External diameter is to be determined using formulas which are appropriately adapted to the contour of the tricycloids.

As far as the contour of the bore of the sleeve part has been described as a convex, this has been done for reasons of better comparison with the shaft part. It goes without saying that the completely concave design of the inner bore of the sleeve part could just as well be mentioned as the convex outer contour of the bore cross section.

Claims

PATENT CLAIMS

1 . Motor vehicle door brake with holding function, comprising a closed sleeve part (2) made of metallic material, which can be connected to one of the door arrangement parts door and door spar, and a shaft part (1) engaging in the sleeve part (2) made of a solid material of metallic material, the other

Door arrangement part is connectable, the shaft part (1) in conjunction with a complementary design of the cross-sectional shape of the bore of the

The sleeve part (2) has, at least over a part of its length corresponding to the sleeve height, a rounding profile deviating from the pure circular shape, characterized in that the cross-sectional shape of the shaft part (1) and the sleeve part (2) is convex over their entire circumference, that the maximum extension of the cross-sectional shape of the shaft part (1) exceeds the minimum extension of the cross-sectional shape of the sleeve part (2), and that the braking effect is brought about by an elastic change in shape of the shaft part (1) and sleeve part (2).

2. Motor vehicle door brake according to claim 1, characterized in that at least one of the shaft part (1) and sleeve part (2) has an elliptical

Has cross section.

3. Motor vehicle door brake according to claim 1 or 2, characterized in that with mutually aligned shaft part (1) and sleeve part (2) an axial assembly without braking action due to elastic

Shape change is possible.

4. Motor vehicle door brake according to claim 1 to 3, characterized in that the cross-sectional shape of the shaft part (1) and the cross-sectional shape of the sleeve part (2) are both elliptical, the large ellipse axis of the shaft part (1) being larger than the small ellipse axis of the sleeve part ( 2).

5. Motor vehicle door brake according to claim 5, characterized in that the overlap dimension (U _e ι), which makes up the difference between the long ellipse axis (a _s ) of the shaft part (1) and the short ellipse axis (b _k ) of the sleeve part (2), of the following Inequality is enough

where dj is the mean diameter of the outer contour of the

Shaft part (1) and inner contour of the sleeve part (2), and d _{a is} the average outer diameter of the material portion of the sleeve part (2) surrounding the inner contour.

6. Motor vehicle door brake according to claim 4 or 5, characterized in that the sleeve part (2) has a curve shape deviating from the pure circular shape of its outer cross section.

7. Motor vehicle door brake according to claim 6, characterized in that the outer cross section of the sleeve part (2) in the area of maximum

Tensions has its largest diameter.

8. Motor vehicle door brake according to one of claims 4 to 7, characterized in that the distance between the focal points of the sleeve part (2) and the focal points of the shaft part (1) to the axis of rotation less than

5% of the respective large ellipse axis.

. Motor vehicle door brake according to one of claims 4 to 8, characterized in that within an angle of rotation range between the shaft part and the sleeve part from 0 to 90 ° an increasing and from 90 ° to 180 ° a decreasing braking resistance due to the elastic shape change of the shaft part (1) and the sleeve part (2) is present.

10. Motor vehicle door brake according to claim 9, characterized in that a corresponding phase shift of the curve of the deformation resistance occurs by providing an angle of rotation of the large ellipse axes relative to one another.

11. Motor vehicle door brake according to claim 1, characterized in that in conjunction with the use of an elastically deformable material for the sleeve, at least within certain limits, relative to the material of the shaft part (1), the course of a cross-sectional shape of at least the sleeve part (not deviating from the circular shape) ) is designed in such a way that there is a constant resistance to deformation within a range of twist angle between the shaft part and the sleeve part of 20 to 70 °.

12. Motor vehicle door brake according to claim 1 or 1 1, characterized in that the shaft part with respect to a non-circular area (1 a), the cross-sectional shape of its body, the cross-sectional shape of the sleeve part compared to a game (6) and that the shaft part (1) is provided with at least one shape which is radially oriented with respect to its general circumferential course and forms a projection (3).

13. Motor vehicle door brake according to claim 12, characterized in that the amount of the radius (3) of the at least one radially directed

Shape (3) of the shaft part (1) is greater than the maximum play (6) between the course of the outer circumference of the area (1a) of the cross-sectional shape of the shaft part (1) that does not deviate from the circular shape. and the course of the inner circumference of the region (2a-d) of the cross-sectional shape of the sleeve part (2) that does not deviate from the circular shape.

14. Motor vehicle door brake according to claim 12 or 13, characterized in that the at least one radially directed projection of the shaft part (1) is associated with a complementary shaped, concave recess (4) marking the closed position of the motor vehicle door in the inner circumference of the sleeve part (2).

15. Motor vehicle door brake according to one of claims 1 1 to 14, characterized in that in the course of the inner circumference of the sleeve part (2), starting from at least one recess marking the closed position of the door (4), the torsion angle range having a constant deformation resistance between

Shaft part (1) and sleeve part (2), as seen in the direction of door opening, is preceded by an area with an in particular continuously increasing resistance to deformation.

16. A motor vehicle door brake according to claim 15, characterized in that the area of rotation having a constant deformation resistance between the shaft part (1) and the sleeve part (2) has an upstream region with an in particular continuously increasing deformation resistance due to the at least one radial projection (3) of the shaft part (1 ) assigned dome-shaped

Recess (4) is formed in the inner circumference of the sleeve part (2).

17. Motor vehicle door brake according to claim 15 or 16, characterized in that, in the course of the inner circumference of the sleeve part (2), the rotation angle range between the shaft part (1) and sleeve part (2), which has a constant resistance to deformation, seen in the door opening direction, an area with a continuously increasing resistance to deformation is connected downstream.

18. Motor vehicle door brake according to claim 17, characterized in that the region having a constant deformation resistance has a range of rotation angle connected with a continuously increasing resistance to deformation by a clearance (6) between

Shaft part and sleeve part reducing flattening (5) is formed in the inner diameter of the sleeve part (2).

19. Motor vehicle door brake according to one of claims 1 1 to 18, characterized in that the shaft part (1) is provided with two mutually opposite, its general circumferential course opposite a radially directed projection (3) forming formations, each of which one of two in The inner circumference of the sleeve part (2) is formed in concave recesses (4) which mark the closed position of the motor vehicle door and that on the inner circumference of the sleeve part (2) there are also two opposing two (6) reducing the play (6) between the shaft part (1) and the sleeve part (2) Flattenings (5) are provided.

20. Motor vehicle door brake according to one of claims 12 to 19, characterized in that the radially directed projections (3) on the shaft part (1) have a circular segment shape in cross section, the radius of the circular segment shape being a fraction of the diameter of the body of the shaft part (1) in whose area does not differ from the circular shape.

21. Motor vehicle door brake according to Claim 20, characterized in that the radius of the circular segment shape of the radially directed projections (3) on the shaft part (1) is in the range between 10 and 50% of the diameter of the region of the body of the body which does not deviate from the circular shape

Shaft part (1).

22. Motor vehicle door brake according to one of claims 14 to 21, characterized in that the radially directed projections (3) on the shaft part (1) complementary, concave recesses (4) in the inner circumference of the sleeve part (2) have a circular segment shape, the radius the circular segment shape in the range between 10 and 50

% of the diameter of the region of the sleeve part (2) which does not deviate from the circular shape.

23. Motor vehicle door brake according to one of claims 1 1 to 22, characterized in that the play between the area of the body of the shaft part (1) which does not deviate from the circular shape and the area of the sleeve part (2) which likewise does not deviate from the circular shape in one area is between 5 and 0.15% of the diameter of the body of the shaft part (1) and that at the same time the height of the elevation of the radially directed projections (3) of the

Shaft part (1) in a range between 5 and 25% of the diameter of the body of the shaft part (1).

24. Motor vehicle door brake according to one of claims 1 1 to 23, characterized in that the transitions of the radially directed projections

(3) are designed on the shaft part (1) in the general circumference of the shaft part (1) with a radius of up to three hundredths of a mm.

25. Motor vehicle door brake according to claim 1 or 2, characterized in that at least one of the shaft part (1) and sleeve part (2) has a tricycloidal cross section.

26. Motor vehicle door brake according to claim 25, characterized in that with mutually aligned shaft part (1) and sleeve part (2) an axial assembly without braking action due to elastic

Shape change of shaft part (1) and sleeve part (2) is possible.

27. Motor vehicle door brake according to one of claims 1 to 25, characterized in that at least one of the shaft part (1) and sleeve part (2) have coated surfaces in the region of a mutual displacement.

28. Motor vehicle door brake according to one of claims 1 to 27, characterized in that the shaft part (1) and the sleeve part (2) are each assigned to a hinge half of a motor vehicle door hinge.

29. Motor vehicle door brake according to one of claims 1 to 28, characterized in that the shaft part (1) and the sleeve part (2) are mutually held by stops provided outside the sleeve height in a starting position rotated relative to an aligned arrangement.

30. Motor vehicle door brake according to one of claims 1 to 29, characterized in that the shaft part (1) and the sleeve part (2) are made of steel.

31. Motor vehicle door brake according to one of claims 1 to 29, characterized in that the sleeve part (2) has an average outer diameter of less than 30 mm.