Bump stop for a vibration damper and a vibration damper for motor vehicles

Abstract

Stop buffer (1) for a vibration damper (2), wherein the stop buffer (1) has a lateral surface and, in a state not subjected to force, a basic geometric shape, and comprises an outer contour for contact with a stop surface (3) and a hollow cylindrical basic structure with an inner contour for coaxial arrangement with a piston rod (4) of the vibration damper (2), wherein the stop buffer (1) has at least one return element (5), wherein the at least one return element (5) returns the stop buffer (1) at least partially to its basic geometric shape, at least in a state not subjected to force, characterized in that the at least one return element (5) has a geometry that is at least partially corrugated.

Description

The present invention relates to a buffer for a vibration damper and a vibration damper for automobiles.Prior ArtIn a large number of embodiments, stop buffers are known in the prior art, in particular as pressure stop buffers or tension stop buffers. Traction stop buffers, also referred to as traction stops, are usually attached to the piston rod of a vibration damper and have the task of limiting the rebound travel of vibration dampers without noise nuisance. Pressure stop buffers, also referred to as pressure stops, are usually attached to the piston rod of a vibration damper and have the task of limiting the compression travel of vibration dampers without noise nuisance.The problem with stop buffers is often the reduced restoring property, in particular after loading of the stop buffer, caused in particular by material fatigue and / or flow behavior and / or irreversible deformation, whereby the function of stop buffers is no longer completely ensured.Such stop buffers are known, for example, from DE 10 2015 202 839 A1, DE 10 2011 116 899 A1, DE 10 2006 007 000 A1, DE 103 25 730 A1, U.S. Pat. No. 2,642,845 A, EP 3 153 738 A1 and DE 10 2005 029 938 B3.The object of the present invention is therefore to provide improved stop buffers in which the aforementioned disadvantages are avoided. In particular, this improved stop buffer is intended to provide an alternative solution to known stop buffers. In addition, the improved stop buffer should be more dimensionally stable and have a higher durability.Disclosure of the InventionThis object is achieved with a stop buffer according to claim 1 and a vibration damper according to claim 9.The stop buffer according to the invention has the advantage over conventional stop buffers that the stop buffer according to the invention, having a geometric starting shape, at least partially, in particular completely, returns at least partially to the geometric starting shape after application of force and thus material fatigue / fatigue phenomena are largely at least partially prevented. In particular, the at least one restoring element of the buffer stop according to the invention can at least partially counteract the flow behavior, in particular an elastic expansion or a plastic deformation of the buffer stop.The vibration damper according to the invention has the advantage over conventional vibration dampers that the vibration damper according to the invention has the advantage of a stop buffer according to the invention, wherein the stop buffer according to the invention, having a geometric starting shape, at least partially, in particular completely, returns to the geometric starting shape after application of force, and thus material fatigue / fatigue phenomena are largely at least partially prevented. In particular, the at least one restoring element of the buffer stop according to the invention can at least partially counteract the flow behavior, in particular an elastic expansion or a plastic deformation of the buffer stop. In particular in the case of loading in critical regions, it is also possible for the tension and / or compression stops to be stopped by the stop buffer of the vibration damper according to the invention.The subject matter of the invention is therefore a stop buffer for a vibration damper, wherein the stop buffer has a lateral surface and, in a non-force-loaded state, has a basic geometric shape, and, for the stop against a stop surface, comprises an outer contour and, for the coaxial arrangement to a piston rod of the vibration damper, comprises a hollow cylindrical basic structure having an inner contour, the stop buffer has at least one restoring element, wherein the at least one restoring element at least partially returns the stop buffer to the basic geometric shape at least in a non-force-loaded state. The at least one restoring element has an at least partially wave-shaped geometry.The invention further relates to vibration dampers for a motor vehicle, comprising a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved back and forth, wherein a working piston can be moved together with the piston rod and at least one stop buffer, wherein the stop buffer has a lateral surface and, in a state in which no force is applied, has a basic geometric shape, and, for the stop against a stop surface, comprises an outer contour and, for the coaxial arrangement with a piston rod of the vibration damper, comprises a hollow cylindrical basic structure having an inner contour, the stop buffer has at least one restoring element, wherein the at least one restoring element at least partially restores the stop buffer to the basic geometric shape at least in a state in which no force is applied.DETAILED DESCRIPTION OF THE INVENTIONIn the context of the present invention, a force-loaded state is understood to mean a state of the buffer stop when a force acts on the buffer stop. For example, a stop buffer arranged on a piston rod of a vibration damper can be subjected to force during the springing-in and / or rebound process of the vibration damper when the stop buffer particularly strikes a stop surface, such as a spring plate.Within the scope of the present invention, a geometric basic shape is understood to mean the geometric starting shape of a stop buffer which has not yet undergone any application of force, in particular no state under which force has yet been applied.In the context of the present invention, a stop surface is understood to mean a surface against which the stop buffer can strike when force is applied, in particular in a state in which force is applied. For example, a spring plate can have a stop surface.In the context of the present invention, "reset" is understood to mean a restoration of the geometric basic shape that existed before the application of force.According to a further preferred embodiment of the invention, the at least one restoring element is arranged in such a way that it at least partially delimits a geometric extent of the buffer stop at least in a force-loaded state of the buffer stop. For example, the at least one restoring element can also completely limit the geometric extent of the buffer stop in the plane in which it is arranged on the buffer stop in a force-loaded state of the buffer stop.According to a further embodiment of the invention, the at least one restoring element is arranged at least partially within the stop buffer. For example, the at least one restoring element is arranged in the stop buffer in such a way that it extends beyond the outer contour of the stop buffer.In a further embodiment of the invention, the at least one restoring element has a higher modulus of elasticity to DIN EN ISO 6892-1. Vol. 2009, discloses that the stop buffer is without the at least one restoring element.According to a further embodiment of the invention, the at least one restoring element is at least partially of annular design.According to a further embodiment of the invention, the at least one restoring element is designed as an at least partially wound spring wire.Within the scope of the present invention, a wave-shaped geometry is understood to mean a wave-shaped profile cross-sectional profile of the at least one restoring element. For example, the wave-shaped profile cross-sectional profile can be polynomial, sinusoidal, triangular or a combination thereof.According to a further embodiment of the invention, the at least one restoring element comprising a metallic material has testability according to DIN EN ISO 6892-1. Year 2009, wherein the at least one restoring element has a yield strength according to DIN EN ISO 6892-1. Year 2009 of greater than or equal to 200 N / mm 2, preferably in a range from 500 to 1600 N / mm 2, particularly preferably in a range from 800 to 1550 N / mm 2, very particularly preferably in a range from 1000 to 1500 N / mm 2.According to a further embodiment of the invention, the at least one restoring element is selected from a group of steels according to DIN 10027-1 year 2005, in particular spring steel, copper, tin, zinc, titanium, an alloy, in particular brass, bronze or a combination thereof.In a further embodiment of the invention, the at least one restoring element is selected from a group of plastics according to DIN EN ISO 1043-1 year 2012, a material according to DIN EN ISO 1043-2 year 2012, according to DIN EN ISO 1043-3 year 2012, according to DIN EN ISO 1043-4 year 2012 or a combination thereof, wherein the at least one restoring element has a yield stress according to DIN EN ISO 527-1:June 2012, which is greater than the yield stress according to DIN EN ISO 527-1:June 2012 of the impact buffer without the at least one restoring element.According to a further embodiment of the invention, the at least one restoring element has a cross section with a geometric shape which is selected from a group of arc-shaped, in particular circular, elliptical, polygonal, in particular octagonal, seven-cornered, hexagonal, pentagonal, quadrangular, in particular rectangular, rhombic, parallelogram-shaped, square, diamond-shaped, triangular, in particular equilateral triangular, isosceles triangular or a combination of one or more of the aforementioned shapes.According to a further embodiment of the invention, the stop buffer is designed as a composite component with at least one elastomer matrix, in which the at least one restoring element is at least partially embedded.In a further embodiment of the invention, the at least one elastomer matrix is selected from a group of an elastomeric composition, in particular thermoplastic elastomers, for example thermoplastic copolyamides, thermoplastic polyester elastomers, thermoplastic copolyesters, olefin-based thermoplastic elastomers, styrene block copolymers, urethane-based thermoplastic elastomers, crosslinked olefin-based thermoplastic elastomers, in particular elastomers, for example rubber, acrylonitrile butadiene rubber, hydrogenated acrylonitrile butadiene rubber, fluororubber, fluorocarbon rubber, ethylene propylene diene rubber, epichlorohydrin rubber, chloroprene rubber, perfluoro rubber, polyurethane elastomer, silicone rubber, liquid silicone rubber, fluorosilicone, fluorosilicone rubber, fluorosilicone rubber, and fluorosilicone rubber, Acrylate rubber, chlorosulfonyl polyethylene rubber, butyl rubber, or a combination thereof.According to a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved to and fro, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the stop buffer has at least one restoring element, wherein the at least one restoring element at least partially returns the stop buffer to the basic geometric shape at least in a state in which it is not acted upon by force.According to a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved to and fro, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one restoring element is arranged in such a way that it at least partially limits a geometric expansion of the stop buffer at least in a force-loaded state of the stop buffer.According to a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved to and fro, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one restoring element is arranged at least partially within the stop buffer.In a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved to and fro, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one restoring element has a higher modulus of elasticity according to DIN EN ISO 6892-1. Vol. 2009, discloses that the stop buffer is without the at least one restoring element.According to a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved to and fro, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one restoring element is at least partially of annular design.According to a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved to and fro, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one restoring element is designed as an at least partially wound spring wire. For example, the wound spring wire is designed as an at least partially circumferential helical spring with a pitch.In a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved to and fro, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one restoring element has an at least partially wave-shaped geometry.According to a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved back and forth, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one restoring element comprising a metallic material can be tested according to DIN EN ISO 6892-1. Year 2009, wherein the at least one restoring element has a yield strength according to DIN EN ISO 6892-1. Year 2009 of greater than or equal to 200 N / mm 2, preferably in a range from 500 to 1600 N / mm 2, particularly preferably in a range from 800 to 1550 N / mm 2, very particularly preferably in a range from 1000 to 1500 N / mm 2.According to a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved back and forth, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one restoring element is selected from a group of steels according to DIN 10027-1 year 2005, in particular spring steel, copper, tin, zinc, titanium, an alloy, in particular brass, bronze or a combination thereof.In a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved back and forth, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one restoring element is selected from a group of plastics according to DIN EN ISO 1043-1 year 2012, a material according to DIN EN ISO 1043-2 year 2012, according to DIN EN ISO 1043-3 year 2012, according to DIN EN ISO 1043-4 year 2012 or a combination thereof, wherein the at least one restoring element has a yield stress according to DIN EN ISO 527-1:June 2012 which is greater than the yield stress according to DIN EN ISO 527-1:June 2012 of the stop buffer without the at least one restoring element.According to a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved to and fro, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one restoring element has a cross section with a geometric shape which is selected from a group of arc-shaped, in particular circular, elliptical, polygonal, in particular octagonal, seven-cornered, hexagonal, pentagonal, quadrangular, in particular rectangular, rhombic, parallelogram-shaped, square, diamond-shaped, triangular, in particular equilateral triangular, isosceles triangular or a combination thereof.According to a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved to and fro, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the stop buffer is designed as a composite component having at least one elastomer matrix, in which the at least one restoring element is at least partially embedded.In a further embodiment of the invention, the vibration damper for a motor vehicle comprises a damper tube which is at least partially filled with damping liquid and in which a piston rod can be moved to and fro, wherein a working piston can be moved together with the piston rod, and at least one stop buffer, wherein the at least one elastomer matrix is selected from a group of an elastomeric composition, in particular thermoplastic elastomers, for example thermoplastic copolyamides, thermoplastic polyester elastomers, thermoplastic copolyesters, thermoplastic elastomers based on olefin, styrene block copolymers, thermoplastic elastomers based on urethane, crosslinked thermoplastic elastomers based on olefin, in particular elastomers, for example rubber, acrylonitrile butadiene rubber, hydrogenated acrylonitrile butadiene rubber, fluororubber, fluorocarbon rubber, ethylene propylene diene rubber, Epichlorohydrin rubber, chloroprene rubber, perfluoro rubber, polyurethane elastomer, silicone rubber, liquid silicone rubber, fluorosilicone, fluorosilicone rubber, acrylate rubber, chlorosulfonyl polyethylene rubber, butyl rubber, or a combination thereof.In a further embodiment of the invention, the elastomer matrix of the buffer stop comprises a base of polyisocyanate polyaddition products, preferably based on cellular polyurethane elastomers, which may optionally contain polyurea structures, particularly preferably based on cellular polyurethane elastomers, preferably having a density according to DIN 53320 of 200 to 1100 kg / m 3, preferably of 300 to 800 kg / m 3, a tensile strength according to DIN 53 571 of greater than or equal to 2 N / mm 2, preferably of 2 to 8 N / mm 2 an elongation according to DIN 53571 of300, preferably 300 to 700%, and a tear propagation resistance according to DIN 53515 of greater than or equal to 8 N / mm, preferably 8 to 25 N / mm.According to a further embodiment of the invention, the elastomer matrix of the buffer stop comprises a base made of a thermoplastic material. Examples of thermoplastics are all plastics which are suitable for being processed by means of injection molding processes. Suitable thermoplastics are both polycondensates and polymers and polyadducts. Suitable thermoplastic polycondensates are polyamides, in particular such as 6,6-polyamide, polycarbonates, polyesters, preferably polyterephthalates such as polyethylene terephthalate and polybutylene terephthalate, polyphenylene oxides, polysulfones and polyvinyl acetates. Suitable thermoplastic polymers are polyolefins, in particular polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, furthermore polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, polyacrylonitrile, polystyrene, high-impact polystyrene, polyacetals, polyvinyl alcohols, polyvinyl acetate, polyoxymethylene and poly-p-xylylene or combinations thereof. Suitable thermoplastic polyadducts are, in particular, thermoplastic polyurethanes.Further suitable thermoplastics, in particular thermoplastic polymers, are styrene-acrylonitrile copolymers (SAN), α-methylstyrene-acrylonitrile copolymers, styrene-methyl methacrylate copolymers and styrene-maleic anhydride copolymers, and also acrylonitrile-butadiene-styrene polymers (ABS), acrylonitrile-styrene-acrylate polymers (ASA), polyoxymethylene (POM), polyamide, polypropylene or combinations thereof.Brief Description of the DrawingsThe stop buffer according to the invention is explained with reference to the drawings. FIG. 1 schematically shows a longitudinal section through a vibration damper with a stop buffer according to an embodiment of the invention, FIG. 2 schematically shows a longitudinal section through a vibration damper with a stop buffer according to an embodiment of the invention, FIG. 3 schematically shows a cross section of a buffer stop according to an embodiment of the invention, FIG. 4 schematically shows a cross section of a buffer stop according to an embodiment of the invention, FIG. 5 schematically shows a cross section of a buffer stop according to an embodiment of the invention, FIG. 6 schematically shows a cross section of a buffer stop according to an embodiment of the invention.FIG. 1 schematically shows a longitudinal section through a vibration damper 2 with a piston rod 4 and a stop buffer 1. The stop buffer 1 is arranged with a hollow cylindrical base structure with an inner contour coaxially on the piston rod 4 and rests on a stop surface 3. A restoring element 5 is arranged within the stop buffer 1. The stop surface 3 is shown in particular as a spring plate.FIG. 2 schematically shows a longitudinal section through the vibration damper 2 with the piston rod 4 and the stop buffer 1. The stop buffer 1 is arranged with the hollow cylindrical base structure with the inner contour coaxially on the piston rod 4 and rests on the stop surface 3. A restoring element 5 is arranged within the stop buffer 1.FIG. 3 schematically shows a cross section of the buffer stop 1 with the restoring element 5 arranged within the buffer stop 1. The stop buffer 1 is shown with a wave-shaped geometry. The restoring element 5 is shown with a wave-shaped geometry, indicated with dashed lines, which follows the wave-shaped geometry of the stop buffer 1 and a rectangular cross section.FIG. 4 schematically shows a cross section of the buffer stop 1 with the restoring element 5 arranged within the buffer stop 1. The stop buffer 1 is shown with a wave-shaped geometry. The restoring element 5 is shown with a wave-shaped geometry, indicated with dashed lines, which follows the wave-shaped geometry of the stop buffer 1, and a round cross section.FIG. 5 schematically shows a cross section of the buffer stop 1 with the restoring element 5 partially arranged within the buffer stop 1. The stop buffer 1 is shown with a wave-shaped geometry. The restoring element 5 is shown with a wave-shaped geometry, indicated with dashed lines, which follows the wave-shaped geometry of the stop buffer 1 and a rectangular cross section.FIG. 6 schematically shows a cross section of the buffer stop 1 with the restoring element 5 arranged around the buffer stop 1. The restoring element 5 is shown with a round cross section.Industrial applicabilityStop buffers and vibration dampers of the type described above are used in the production of vibration dampers and motor vehicles.List of reference characters1 Stop buffer 2 Vibration damper 3 Stop surface 4 Piston rod 5 Restoring element

Claims

Stop buffer (1) for a vibration damper (2), wherein the stop buffer (1) has a lateral surface and, in a state not subjected to force, has a basic geometric shape, and, for the stop against a stop surface (3), comprises an outer contour, and, for the coaxial arrangement with a piston rod (4) of the vibration damper (2), comprises a hollow cylindrical basic structure having an inner contour, wherein the stop buffer (1) has at least one restoring element (5), wherein the at least one restoring element (5) at least partially restores the stop buffer (1) at least in a state not subjected to force into the basic geometric shape, characterized in that the at least one restoring element (5) has an at least partially undulating geometry.The impact buffer (1) according to claim 1, characterized in that the at least one restoring element (5) is arranged such that it at least partially limits a geometric extension of the impact buffer (1) at least in a force-loaded state of the impact buffer (1).The buffer stop (1) according to any one of claims 1 to 2, characterized in that the at least one restoring element (5) is arranged at least partially within the buffer stop (1).Stop buffer (1) according to one of Claims 1 to 3, characterized in that the at least one restoring element (5) has a higher modulus of elasticity to DIN EN ISO 6892-1. Year 2009, the stop buffer (1) without the at least one restoring element (5).Stop buffer (1) according to one of Claims 1 to 4, characterized in that the at least one restoring element (5) is at least partially of annular design.Stop buffer (1) according to one of Claims 1 to 5, characterized in that the at least one restoring element (5) comprising a metallic material can be tested in accordance with DIN EN ISO 6892-1. Year 2009, wherein the at least one restoring element (5) has a yield strength according to DIN EN ISO 6892-1. Volume 2009 of greater than or equal to 200 N / mm 2.The stop buffer (1) according to any one of claims 1 to 6, characterized in that the at least one restoring element (5) has a cross section with a geometric shape selected from a group of arc-shaped, polygonal or a combination thereof.The stop buffer (1) according to any one of claims 1 to 7, characterized in that the stop buffer (1) is formed as a composite component with at least one elastomer matrix, in which the at least one restoring element (5) is at least partially embedded.Vibration damper (2) for a motor vehicle, comprising a damper tube which is at least partially filled with damping liquid and in which a piston rod (4) can be moved to and fro, wherein a working piston can be moved together with the piston rod (4) and at least one stop buffer according to one of the preceding claims 1 to 8.

Images