MXPA99001821A - Method for adjusting a diaphragm spring - Google Patents

Abstract

The invention relates to a method for adjusting the fingers of a diaphragm spring.

Description

F PROCEDURE FOR ADJUSTING A MEMBRANE SPRING FIELD OF THE INVENTION The invention relates to a method for adjusting a membrane spring, in particular to adjust the axial height and / or the course of the arms of a membrane spring.

BACKGROUND OF THE INVENTION This type of membrane springs were disclosed, for example, through German Patents DE-OS 34 28 001, DE-OS 33 04 670 and US Patents US-PS 3 977 504 and US Pat. -PS 3 951 393. In the case of springs of In the case of a diaphragm, or disc, which are provided with respect to their action in a frictional engagement between the housing and the clamping plate, it has already been known to adjust the tabs directed radially inwardly of the disc spring installed on the disc. the friction coupling, individually by means of a device having a plurality of movable seals, to bring the tips of the tabs that are radially inward at least approximately at the same axial height. In this way, the application in the The friction coupling of a driving force by means of a disengaging receptacle allows the operation and the efficiency of the friction coupling, as well as the disengagement system assigned thereto, to be considerably improved. In particular, in this way the drive path required for frictional engagement can be reduced. In addition, in this way a more homogeneous load of various friction coupling components, or of the disengagement system, is achieved. In particular, in this way, too high a tilting force on the release housing and thus on the release device can be avoided. A tilting such as this is disadvantageous, particularly in the case of a disengagement device with an axial displacement of a guide tube on the gear side, since by means of a tilting of this type the driving force is increased and the wear on the guides increases considerably. Furthermore, by applying a more homogeneous force on the periphery in the area of the tips of the tabs, a stretching or warping of the disk spring, in particular in the area of its annular base body, can be largely prevented. that is radially outside.

OBJECTIVES AND ADVANTAGES OF THE INVENTION The present invention was based on the objective of making possible in a simple and economic way a simple and economical adjustment of the course of at least one, or of certain arms of a membrane spring, or, a adjustment of the relative course of at least certain arms to each other and / or the adjustment of the height of at least the free ends of certain arms of a membrane spring. Furthermore, it is intended by the invention to guarantee a particularly simple and inexpensive configuration of the device necessary for the adjustment, or the orientation of at least certain arms of a membrane spring. According to a variant of the invention, the above is achieved when at least one arm of the membrane spring is heated in such a way in a predetermined area, that said zone and / or the sections of the arm that border this zone can be adjusted without considerable deformation or practically without elastic deformation. The partial heating of the arm can be carried out in such a way that a region between the ends of the arm is heated accordingly, so that the sections of the arm which are provided on both sides of said arm can be adjusted with respect to each other. others, whereby also the free end of the corresponding arm can be brought to an axial position defined in relation to the longitudinal axis of the membrane spring. However, it is also possible to heat and orient only the free ends, or the tips of the arms. further, at least two areas or areas of at least one arm can be heated to adjust them. The zones can be heated simultaneously or with phase shift over time. Thus, for example, an intermediate zone and the tips of the arm can be heated. By rapid cooling, at least one of these zones can be hardened at least partially. According to a variant of the invention, the at least one arm to be oriented of a membrane spring can first be loaded with respect to flexion and subsequently reduce at least partially the stresses that are thus generated in the arm, by heating a arm area tensed. By means of heating, at least the elastic tension of the arm is reduced or practically eliminated completely. Advantageously, the heated zone can be cooled in such a manner after orienting the at least one arm, that at least one partial hardening is again obtained in said zone. A process according to the invention can be used in particular in membrane springs, or disk springs, which already before orienting at least one arm, preferably a plurality and even all the arms (optionally with the exception of an annealing and / or a hardening of the tips of the arms), are finished thermally treated in terms of their elastic properties. After the adjustment process, when discharging the arms, guarantee a spring, or readjust as little as possible, or practically none of the arm, or, of the arm sections, it is convenient if by heating in the zone of deformation of each arm reduces the resistance of the material to a very small value in comparison with the resistance existing in the other zones of the corresponding arm. The strength of the material in the heated deformation zone must therefore be reduced, at least in certain areas, to a value close to 0 N / mm2. Advantageously, the membrane spring can be at least partially radiated before adjusting the arms relative to each other. The areas to be heated by the arms can be positioned in such a way that at least partial heating of the membrane spring results. This heating is due to the heat which, by the conductivity of the material, radiate the heated zones to the elastically deformable or elastic areas of the membrane spring. These zones can be configured, for example, by an annular base body of the disk spring. Advantageously, the method can find application in disk springs, which have an annular base body, which serves as an energy accumulator, which in its radially internal and / or radially external zone has arms formed in one piece, for example, in the form of tongues. These arms can be projected in the radial direction and / or in the peripheral direction. Advantageously, a disk spring of this type, or at least its annular base body, in the decompressed state, can have a conical shape. It may be particularly advantageous if the tabs have radially inward recesses, which are separated with radially extending recesses, like slots. Advantageously, in order to orient the arms to each other, all of them can be controlledly heated in a predetermined area, ie in a delimited area, and deformed together. In particular in the case of disk springs which are used in conjunction with friction couplings, it may be particularly convenient that by orienting the arms, or the tongues, at least their free ends abut, or touch the less approximately a plane perpendicular to the axis of rotation of the membrane spring, or of the disk spring. For some application cases, however, it can also be advantageous that at least certain arms, at least during a partial area of their longitudinal projection, they have a course displaced with respect to the other arms, it being possible to generate or correct said course with the method according to the invention. In particular in the case of disk springs, installed in friction couplings, with tabs directed radially inwards, the tips of which can be loaded axially by a driving means, such as a disengagement housing, it is especially advantageous that said tabs tips, thanks to the adjustment process according to the invention, they reach at least approximately at the same axial height. For the method according to the invention, it is advantageous for the arm zones to be heated to be heated to a temperature between 600 and 950 °, preferably at a temperature in a range of approximately 850 °. The aforementioned temperatures should be considered in relation to membrane springs made of steel. Depending on the material, however, higher or lower temperatures may also be desirable. The processes according to the invention can find application both in the membrane spring itself, that is to say in the individual component, as well as in membrane springs which are respectively installed in a structural unit, such as, for example, in a friction coupling . When using this type of membrane springs in friction couplings, it can be completely installed or only partially when using the corresponding procedure. Thus, for example, the membrane spring can only be connected in a rotatable manner to the coupling housing. However, it is particularly advantageous that the corresponding method is applied on fully assembled friction couplings. In this case, it is particularly advantageous if the diaphragm spring or the disc spring has an unpacked position which is at least approximately in accordance with that position which the spring adopts in the coupling installed in the vehicle. The above can be effected by a corresponding positioning of the pressure disc in relation to the housing, because in this way the disc spring is compressed. Advantageously, the zones to be heated can be inductively heated. The inductive heating can be carried out with the rotating part and / or a rotating coil. The coil generates an alternating magnetic field, which induces eddy currents in the work piece, which produce a rapid increase in temperature. However, a so-called combustion heating, that is to say a flame heating, can also be carried out. It may be particularly convenient to provide at least two coils, of which one heats the zones for orienting the arms and the other is used for heating and hardening the free arm points. By means of a cooling or very rapid quenching in the area of the arm tips, a hardness can be achieved which is above that which exists in the other areas of the arms and / or in the entire membrane spring.

BRIEF DESCRIPTION OF THE DRAWINGS With the help of the figures, the invention is illustrated in more detail in relation to a possible embodiment or application thereof. They show: Figure 1, a section through a device for carrying out the procedure. Figures 2 to 4, certain phases of the course of the procedure, or, process. And Figures 5 to 7, a disk spring that in the Figure 7 is integrated in a friction coupling. DETAILED DESCRIPTION OF THE INVENTION As can be seen in Figure 1, the device 1 for carrying out the method according to the invention consists of a lower part 2 and an upper part 3, or vice versa, which are housed in a frame closed in itself, which is not shown in its entirety. A part of the upper plate 4 can be seen from the frame, which is attached to a lower disc not shown, by means of a braced anchor 5. In the upper plate 4 the upper part 3 is fixed. The lower part 2 can be displaced axially with respect to the upper part 3, by means of a drive, for example, a hydraulic cylinder 6, of which only the rod of the piston can be observed. The lower part 2 and the upper part 3 are connected to one another, or guided to be fixed against rotation, but axially movable relative to each other, by means of guide columns 7 and guide sleeves, or guide housing 8. The part • Lower 2 has a receiving plate 9, which can be charged through the hydraulic cylindrical 6 and carrying the guide housing 8. Furthermore, a reception receiving ring 10 is provided on the receiving plate 9, which axially supports the receiving plate 9 and receives a housing 11, in this case in the form of a spherical housing. A receiving device 12 rests on the receiving plate 9 on the receiving plate 9. It can be rotated through the housing 11 with respect to the receiving plate 9. In the illustrated embodiment, the receiving device 12 it consists of at least one annular ring 13, which carries several fastening elements in the form of fastening bolts 14, distributed on the periphery. At least some of the fastening bolts receive centering means in the form of centering pins 15, which preferably can be inserted axially into the fastening bolts, at least partially, namely respectively against the action of the energy accumulator, the which can be configured, for example, by a coil spring 16. In the receiving plate 9, or in the housing receiving ring 10 there is also an adjustment device 17, with an adjustment cylinder 18, which it can axially displace, or load, an adjustment seal 19, which, in the present case, consists of several components together. The adjustment seal 19 is guided in a guide reception 20, which in this case also consists of several components together, in an axially displaceable manner and without any or virtually no possibility of tilting. The guide reception 20 has a pot-shaped component 21, which receives, or at least partially covers, the adjustment cylinder 18 and is fixedly connected to the receiving plate 9. The upper part 3 also has a plate of receiving 22 to which a housing receiving ring 23 is fixed, which carries a housing in the form of a roller housing 24. Through the housing 24, a support device 25, which consists of several discs, or , rings, axially rests on the receiving plate 22 and is rotatably received relative thereto. The housings 11 and 24 are arranged coaxially with each other, so that also the receiving device 12 and the supporting device 25 can rotate coaxially with each other. In the illustrated embodiment, the support device 25 has a pulley 26, which can be rotated through a belt 27 and a drive motor 28. The device 1 also has a heating device 29, which serves for the at least partial heating of the arms of a component, such as in particular a membrane spring, where by the cooperation of the heating device and the other components of the device 1, it is possible to adjust the arms , as will be described in more detail later. In the embodiment shown, the heating device comprises an annular induction coil 29. The device 1 serves to adjust each arm of a membrane spring relative to one another, said membrane spring being formed in the present case by the disc spring 30 of a friction coupling 31. As can be seen in Figures 5 to 7, the disc spring has an annular base body 32, from which tabs 33 directed radially inward, delimiting a central recess 34. The tongues of the disc spring 33 are separated from each other through slots 35, which are radially inwardly. in conjunction with the central notch 34 and open radially outward in perforation-like extensions 36, which abut the annular base body 32. In Figure 6, the fully illustrated position of the disc spring 30 is in accordance with the fully decompressed state of said disc spring. disc spring. In the embodiment shown, the tongues of the disc spring 33 are bent or bent and the internal tips of the tongues 37 have a capsular shape. As seen in Figure 7, the friction coupling 31 can be mounted on a back pressure disc, such as a flywheel 38, the friction linings being tensionable between the back pressure disc 38 and the pressure disc 39 of the friction coupling 31. of a coupling disc 40. The pressure disc 39 is charged in a manner known per se by the disc spring 30. This disc is received in a manner known per se in the coupling housing 41, namely in the illustrated embodiment , in the manner of a two-armed lever. Friction couplings of this type were disclosed, for example, in US Pat. No. 5301782 and German Patent DE-OS 4434019. However, the invention can also find application in so-called pull couplings, such as they were disclosed, for example, through US Pat. No. 4,909,370 and German Patent DE-OS 4 237 623. Next, with the help of Figures 2 to 4, a $ - .. describes the course of the procedure, or the process * ~ -_, to adjust the tabs of a disc spring, which is already mounted in a friction coupling. In the first phase, the friction coupling consisting of at least the pressure disk 39, the disk spring 30 and the housing 41 is placed in the device 1. In the illustrated embodiment, the frictional coupling is received in the device 1 with pressure disc 39 pointing upward, resting axially on shows the tips of the tongues 37 in the adjustment seal 19. The positioning, or axial centering of the friction coupling 31 is effected in the embodiment shown through the coupling housing 41, which presents on its edge external 42 recesses in which centering pins are axially inserted 15. It is convenient to provide at least two clav :; .3 of centering 15. However, it is also possible to provide for m = "centering pins, it being advantageous that there are three of these centering pins, which, as As already described, they are housed in an axially displaceable manner in the fastening elements in the form of fastening bolts 14. The number of fastening elements 14 must be at least three, it being advantageous for there to be 6 of these fastening elements. which can be distributed homogeneously along the periphery.

After the friction coupling 31 is housed in the device 1, the lower part 2 is displaced upwards by the drive, or, the hydraulic cylinder 6, the pressure disk 39 and the centering pins 15 first resting on the upper part 3. The support of the components 39, 15 in the upper part 3 can occur practically simultaneously or delayed in time. The corresponding position is shown in Figure 3. As the lower part 2 continues to rise, the centering pins 15 are inserted axially into the respective clamping elements 14, said clamping elements 14 resting on the coupling housing, or the coupling cover 41, after traveling a certain path. At least then, the housing 41 moves axially in the direction of the fixed pressure disc, until said housing 41 rests on an adjustment element in the form of an adjustment ring 43 carried by the upper part 3. Subsequently, the marginal zone 42 of the housing 41 is tensioned between the ring 43 and the clamping element 14. This position is shown in Figure 4. It should be noted that the above development can be carried out with the adjustment cylinder 18, or, the adjustment seal 19 completely in the desired position. In this case, when the lower part 2 is raised, as soon as the pressure disc 39 is axially supported on the upper part 3, the disk spring 30 rotates, since it is supported radially outside on the pressure disc 39, which is then axially fixed, and radially inwards, in the area of the tips of the tabs 37, is loaded by the adjustment seal 19. According to another variant, however, the adjustment cylinder 18, or, the adjustment seal 19 can also be found in a retracted position during the upward movement of the lower part 2 and brought to the desired axial position just after the encounter between the lower part 2 and the upper part 3 of the adjusting cylinder 18, or, of the adjusting seal 19. Simultaneously , a path and / or force measurement can be made, which allows conclusions to be drawn about the actuation state of the friction coupling. In FIG. 4 the final position of the device 1 necessary to adjust the height of the tips of the tabs of the disk spring 37 is shown. In this actuation state of the friction coupling 31, the tabs of the disk spring 33 are pre-stressed with a value determined with respect to the nominal measure of the desired height of the tabs of the disk spring, namely about a value of about 1.5 mm. This value, however, can also be higher or lower. But the pretension must be carried out in such a way that it is possible to adjust the tabs eliminating the bending stresses applied to them. In the embodiment shown, as already described in relation to Figure 1, the receiving device 12 and the supporting device 25 are rotated by means of a drive 27 and 28, the induction coil 29 being activated simultaneously or shortly before or shortly thereafter, so that the contiguous zones 44 of the tabs of the disk spring 33 are heated at least in parts to the desired temperature, which is preferably about 850 ° C. Due to the heating, the resistance in the corresponding zones is strongly reduced, so that the sections of the tongues 33 that are on both sides of said zones can be decompressed almost completely. Thus, the difference in height that originally occurred between the tips of the tabs 37 can be compensated for, or reduced to a measure at least acceptable. After the heating of the zones 44 and the decompression of the tongues of the disk spring 33, the zones 44 can be controlledly cooled, so that a hardening of said zones is again achieved. The cooling thereof can be effected, for example, by means of a turbine, which is integrated directly into the device 1, for example, in the area of the component that can be rotated by the drive 27 + 28. However, it is also it can provide a fan, or a turbine, which passes cooling air, for example, through the opening 4a in the area of the upper part 3. In the illustrated embodiment, the induction coil 29 is provided on the side opposite the disc spring cover 30; however, the coil 29 can also be placed on the other side of the disk spring 30 or on both sides of the disk spring 30 a coil can be provided respectively. In the described method, the tabs of the disk spring 33 are already tensioned when the heating of the zones 44 starts. According to another variant, however, this pretensioning can also be carried out only during or shortly after the heating of the zones 44. According to At the time of loading the tips of the tongues 37, there is practically no elastic tensioning of the tongues of the disc spring 33, since upon reaching the temperature provided in the zones 44, they present only a very small resistance or practically none. A method of this type can be obtained, for example, when starting the heating of the zones 44, the adjustment cylinder 18, or, the adjustment seal 19 is in a retracted position and only after reaching or shortly before to reach the desired deformation temperature, they rise again to the position necessary for the adjustment of the tips of the tabs 37. As soon as the adjustment process is completed, the rotating parts are stopped or stopped and the device is opened. 1, so that friction coupling 31 can be removed. The radial zone in which the sections 44 to be heated are located can be selected in such a way that, by heating said sections or zones 44, it occurs simultaneously at least a partial compression of the disk spring 30. Said compression is due to the fact that the heat applied to the zones 44 acts at least on the internal marginal region of the annular base body 32 of the disk spring 3 0. Therefore, with the method according to the invention, a type of hot compression of the disk spring can be carried out simultaneously. According to one embodiment, or a development of the invention not shown, another induction coil can be provided in the device 1, which can be used to harden the tips of the tongues of the disk spring 37. In a hardening like this, the tips of the tabs of the disk spring 37 are brought to a greater hardness than that existing in the other regions of the disk spring 30. A coil of this type is shown in FIG. 4 and is indicated with reference 45. The cooling of the tips of the tongues can be effected again by air or in another way (for example, cooling with liquid). The hardening of the tips of the tongues 37 can be carried out simultaneously with the heating and hardening of the zones 44, or also, after or before them. If in the hardening of the tips of the tabs 37 the adjustment seal 19 rests on them, it is particularly convenient that said adjustment seal 19 has at least one component, for example, in the form of a disk 19a, which comprises of a non-conductive or non-magnetizable material, such as a ceramic material. The material must have a very small thermal conductivity. According to a variant embodiment of the method or of the invention, the adjustment of the tongues 33 relative to one another by means of the corresponding change of shape of the device 1 can also be carried out only on the membrane spring or spring of disk 30. Although the invention in relation to the description of the figures was described mainly with respect to a disc re-spline 30, in which all tips of the tabs 37 are brought at least approximately at the same axial height , the method according to the invention can also use membranes in which there are arms, or tongues which, at least in part of their projection, have a different course, or whose tongue tips have a different height, that is, they are displaced from each other. This type of membrane springs were made known, for example, through German Patents DE-OS 19524827, DE-PS 3643781, DE-OS 3528660, DE-OS 3513315 and DE-OS 2460963. The investigations carried out in connection with the invention, resulted in the hardness of the tongues of the disc spring 33 in the inductively heated zone 44 can be increased by a strong cooling, a transition zone being able to result in the other sections of the tongues 33, in which a decrease in the hardness is observed. By means of the method according to the invention, the tips of the tongues 37 can be brought to a height range with a maximum bandwidth of +/- 0.3 mm with respect to a desired reference height. The tests carried out in connection with the invention showed that a bandwidth of +/- 0.2 mm or even less can be maintained. If the difference in height, or the displacement that eventually remains between the tips of the tabs 37 is very small, for example, of around 0.1-0.3 mm, in accordance with a development of the invention, said displacement can be less reduce more by mechanical processing, for example, sanding the tips of the tongues 37. In this way a frictional coupling is ensured, which when activated, ensures a still homogeneous application of the force of disengagement by means of the tabs 33 in the annular base body 32. Furthermore, the above is advantageous for the disengagement housing of the disengagement device acting on the tips of the tongues 37, which is necessary to drive the friction coupling 32, since the housing is homogeneously loaded and, thus, virtually no tilting force acts on the disengagement device. Disc springs 30 with adjusted tongue tips 37 may find application in a particularly advantageous manner in relation to friction couplings, which present a readjustment anticipation that compensates for wear of the friction linings. This type of friction couplings were disclosed, for example, in German Patent DE-OS 4 239 291, DE-OS 4 306 505, DE-OS 4 239 289, DE-OS 4 322 677 and DE- OS 4 412 107. In the described embodiment, the device 1 is configured in such a way that the friction coupling or the disc spring rotates at least during the heating of the respective areas of the tongues. The device 1, however, can also be configured in such a way that during the corresponding heat treatment the coupling, or the disk spring does not rotate and, instead, the coil 29 and / or the coil 45, i.e. , the heating means, rotate. When adjusting the tabs of a disk spring, in accordance with a development according to the invention, a pressure piece can already be mounted on the tips of the tongues 37 (as is known, for example, from the German Patent DE- OS 34 24 227 and US Pat. No. 2 835 366) or a disengagement housing (as is known, for example, from German Patent DE-OS 23 27 937). The invention is not limited to the embodiment of the description, but, within the scope of the invention, numerous variations and modifications are possible, in particular those variants, elements and combinations and / or materials, which, for example, by combination or transformation of properties, or elements or steps of the process according to the invention illustrated in the general description and in the embodiments, as well as in the claims, and contained in the drawings, and by combinable properties, lead to a new object or to new stages or sequences of process steps, even if they refer to manufacturing, testing and work procedures.

Claims (23)

1. NOVELTY OF THE INVENTION Having described the above invention, it is considered as a novelty, and therefore, the content of the following is claimed as property: CLAIMS 1. A method for adjusting the axial height of the arms of a membrane spring, characterized in that at least one arm is heated in such a way in a predetermined area, that the arm sections provided on both sides of said arm can be adjusted one with respect to the others without considerable elastic deformation or practically without elastic deformation.
2. 2. A method for adjusting the axial height of the arms of a membrane spring, characterized in that at least one arm is required in terms of bending load and at least the stresses generated thereby in the arm are at least reduced by heating from a zone of the tensioned arm.
3. 3. A method according to claim 1 or 2, characterized in that the bending stresses are virtually eliminated by partial heating.
4. 4. A method according to claim 1, characterized in that after adjusting the at least one arm, the heated zone is cooled in such a way that there is at least a partial hardening in said zone.
5. 5. A method according to claim 1, characterized in that the diaphragm spring, before the adjustment of the arms to each other (possibly with the exception of an annealing of the membrane spring and / or a hardening of the tips of the diaphragms. arms), it is finished to treat thermally in terms of its elastic properties.
6. 6. A method according to claim 1, characterized in that, by heating, in the deformation zone the material resistance is reduced at least in parts to a value close to 0 N / mm2.
7. 7. A method according to claim 1 of claim 1, characterized in that the membrane spring is at least partially radiused before adjusting the arms.
8. 8. A method according to claim 1, characterized in that, by heating in parts of the arms, at least partial hot compression of the membrane spring is obtained.
9. 9. A method according to claim 1, characterized in that the diaphragm spring is formed by a disk spring with an annular base body acting as an energy accumulator, from whose radially internal peripheral zones and / or Radially external arms project in the form of tongues.
10. A method according to claim 9, characterized in that the disk spring, in the decompressed state, has a conical shape and tabs that indicate radially inward, which are separated from one another by radially extending recesses, as slots.
11. 11. A method according to claim one of the preceding claims, characterized in that to adjust the arms to each other, all of them are heated in a predetermined area and are deformed together.
12. 12. A method according to claim 1, characterized in that by adjusting the arms, at least their free ends rest at least approximately in a plane perpendicular to the axis of rotation of the membrane spring.
13. 13. A method according to claim as in at least one of the preceding claims, characterized in that the diaphragm spring formed as disk spring has tabs radially projected inwardly, the tips of which can be loaded axially by means of a drive means, wherein said tips of tongues, due to the adjustment process, they are brought at least approximately to the same axial height. 1 .
14. A method according to claim at least one of the preceding claims, characterized in that the areas of the arms to be heated are heated to a temperature between 600 and 950 °, preferably at a temperature of about 850 °.
15. 15. A method according to claim as in at least one of the preceding claims, characterized in that the membrane spring is treated individually according to the method.
16. 16. A method according to claim 1 of claim 1, characterized in that the membrane spring is treated in the installed state.
17. 17. A method according to claim 16, characterized in that the membrane spring is installed at least in the coupling housing.
18. 18. A method according to claim 16 or claim 17, characterized in that the method is applied to the friction coupling completely assembled.
19. 19. A method according to claim as in at least one of the preceding claims, characterized in that the heated zone of the arm is at least approximately in a central section of the projection length of the arm.
20. 20. A method according to claim as claimed in at least one of the preceding claims, characterized in that the zones are heated inductively.
21. 21. A method according to claim 20, characterized in that the heating is carried out by means of a coil.
22. 22. A method according to claim as in at least one of the preceding claims, characterized in that at least two coils are provided, one heating the zones for the adjustment of the arms and the other being used for heating and hardening of the tips. free of arms.
23. 23. A friction coupling, in particular for vehicles, characterized in that it has a membrane spring, which was manufactured in accordance with at least one of the preceding claims of the process.