DE102006049093A1 - Vibration damper for motor vehicle, has annular gap formed between stamp and operating tube, and dimensioned such that particles are displaced through gap in axial direction during movement of stamp - Google Patents

Abstract

The invention relates to a vibration damper (10) comprising a cylindrical working tube (12), a working chamber (16) which is filled with a damping medium (14) in the working tube (12) and an axial direction (a) in the working chamber (16). movably arranged, via a piston rod (18) guided pressure plunger (20). Here, the damping medium (14) is formed as a spherical particles having granules, and between the plunger (30) and the working tube (12) an annular gap (22) is formed, which is dimensioned such that upon movement of the plunger (20). the spherical particles of the granules through the annular gap (22) in the axial direction (a) are displaceable.

Description

The The invention relates to a vibration damper according to claim 1.

Vibration damper are Well known from the prior art. Depending on the underlying lying action principle, the vibration damper as a so-called hydraulic or mechanical vibration absorbers designated. In the following, only the hydraulic vibration damper will be considered, because of this structurally and functionally the most similarities with the vibration damper according to the claim 1 has.

A hydraulic damper essentially comprises a cylinder filled with a hydraulic fluid and a piston guided therein via a piston rod. During an axial movement of the piston rod or the cylinder, the hydraulic fluid is moved through narrow channels and valves. With the speed of the piston movement increases the flow resistance of the hydraulic fluid and thus the damping effect. Such a hydraulic vibration damper is for example in the DE 196 28 152 C2 described.

such hydraulic vibration absorbers have the disadvantage that they work strongly dependent on temperature and therefore a certain, especially at low outside temperatures binding exhibit.

Out the field of motor vehicle construction, it is known in the articulation a flap or a lid a spring-damper element in the form of a Gas spring to use. The disadvantage here is the fact that Gas springs a relatively expensive Represent component. In addition, gas springs work, comparable to one hydraulic vibration damper, also strongly temperature dependent. That in cold outside temperatures is also with gas springs to observe a binding, what consequently opening or closing the flap or lid difficult.

Of the Invention is based on the object, a vibration damper for disposal to provide that works temperature-independent while avoiding the disadvantages mentioned.

These The object is solved by the features of claim 1.

The under claims 2 to 5 form advantageous developments of this invention.

A Another object is to provide a pivotable linkage of a Flap or a lid to a motor vehicle with an intermediate the flap or the lid and a body component of the motor vehicle arranged spring and damper element educate in such a way that even at low temperatures a smooth running of the to open or to be closed Flap or lid guaranteed is.

These The object is achieved by the characterizing features of the claim 6 solved.

Of the Subclaim 7 forms an advantageous development of this arrangement.

Of the The invention is based on the finding that the temperature dependence the damping medium used the temperature dependence of vibration certainly.

To invention, the vibration damper comprises a cylindrical working tube, a trained in the working tube, filled with a damping medium working chamber and a movable in the axial direction in the working chamber, via a Guided piston rod Plunger. The damping medium in the working chamber is as having a substantially spherical particles Granules formed. The outside diameter the plunger and the inner diameter of the working tube are while dimensioned to each other, that between the working tube and Plunger remains a corresponding annular gap, which in a Movement of the plunger a displacement of the spherical particle of the Granules in the axial direction through the annular gap allows. The initiated by a movement of the plunger relative movement between the individual spherical ones Particles of the granules causes the occurrence of frictional forces between the single spherical one Particle. The resulting frictional force dampens the movement of the plunger and convict one Part of kinetic energy in heat. Because the friction forces independent between the particles from the outside temperature is in a simple way now a vibration damper for disposal placed, the temperature independent is working. Consequently, even at low outside temperatures a smooth operation of the vibration allows. Another advantage is that the vibration damper due its simple, only a few components comprehensive structure inexpensive to produce is.

Preferably, the working tube with its inner diameter D _I and the plunger with its outer diameter D _{A has} a diameter ratio D _I / D _A of 0.5 to 0.8, while the spherical particles of the granules have a diameter of 2.5 to 3.5 mm have. Experiments have shown that with these diameter ranges opti male attenuation values can be achieved.

In Advantageously, the granulate is a plastic granulate, in particular POM (polyoxymethylene) or alternatively ABS (acrylonitrile-butadiene-styrene copolymer) or ASA (acrylic ester-styrene-acrylonitrile), because a plastic granulate only a low specific weight has, cost-effective The purchase is durable and due to its robustness of the vibration damper guaranteed.

As Experiments and simulations have shown, it is beneficial to the Forming punch with a conical or spherical stamp shape. The Formation of the plunger with a conical or spherical stamp shape In the present case, this is not an exhaustive list, as it also applies to others Stamp shapes corresponding damping characteristics to be realized.

Especially can over the selection of the stamp shape of the plunger and a corresponding Selection of the diameter of the spherical particles of granules adjusted in a simple manner, the damping efficiency of the vibration become.

moreover The invention relates to the articulation of a flap or a lid on a motor vehicle with a between the flap and the lid and a bodywork component of the motor vehicle arranged damping and spring element. According to the invention here is the damping element as a vibration damper formed according to one of the preceding claims. The usage such a vibration damper proves to be advantageous because this cheaper than a previously customary used gas spring is and also at low outside temperatures a smooth running the flap or the lid guaranteed is.

Preferably is provided that the spring element arranged parallel to the damping element is. The parallel arrangement proves to be advantageous, as a result a simple assembly of the two elements is ensured.

Further Advantages, features and applications of the present Invention will become apparent from the following description in conjunction with the embodiment shown in the drawing.

The Invention will now be described with reference to the drawing Embodiment described in more detail.

In the description, in the claims, in the abstract and in the drawing are the ones listed below the reference numbers used terms and associated reference numerals used.

In the drawing mean:

1 a simplified representation of a vibration damper according to the invention.

An in 1 in a simplified representation more or less schematically and in total with the reference numeral 10 designated vibration damper essentially comprises a cylindrical working tube 12 , one in the working tube 12 trained, with a damping medium 14 filled working chamber 16 , as well as one in the working chamber 16 arranged in the axial direction a movable, via a piston rod 18 guided printing stamp 20 ,

The damping medium is in this case formed as a spherical particle having granules. The present is the working chamber 16 filled with a plastic granules of polyoxymethylene (POM).

Between the plunger 20 and the working tube 12 is an annular gap 22 formed, which is dimensioned such that upon movement of the plunger 20 the spherical particles of the plastic granules through the annular gap 22 are displaceable or movable in the axial direction a. The friction generated by the movement between the individual spherical particles dampens the movement and converts part of the kinetic energy into heat. Since the friction force between the particles is independent of the outside temperature, the vibration damper according to the invention operates 10 independent of temperature.

In the present case, the working tube 12 with its inner diameter D _I and the plunger 20 with its outer diameter D _{A has} a diameter ratio D _I / D _A of 0.5, while the spherical particles of the granules have a diameter of about 2.5 to 3.5 mm. Via a corresponding selection of the diameter ratio D _I / D _A , as well as the selection of the particle diameter of the granules, a first possibility for adjusting the damping characteristic of the vibration damper 10 made available.

As 1 can still be seen, the plunger has 20 in the present case, a substantially hemispherical stamp shape. By selecting a corresponding stamp shape, a further "set screw" for adjusting the damping characteristic is provided.

10

vibration

12

cylindrical working tube

14

damping medium

16

working chamber

18

piston rod

20

plunger

22

annular gap

a

axial direction

Claims (7)

Vibration damper ( 10 ), comprising a cylindrical working tube ( 12 ), one in the working tube ( 12 ), with a damping medium ( 14 ) filled working chamber ( 16 ) and one in the working chamber ( 16 ) arranged in the axial direction (a) movable, via a piston rod ( 18 ) guided, plunger ( 20 ), wherein the damping medium ( 14 ) is formed as a spherical particles having granules and between plunger ( 20 ) and working tube ( 12 ) an annular gap ( 22 ) is formed, which is dimensioned such that upon movement of the plunger ( 20 ) the spherical particles of the granules through the annular gap ( 22 ) in the axial direction (a) are displaceable. Vibration damper according to claim 1, characterized in that the working tube ( 12 ) with its inner diameter D _I and the plunger ( 20 ) have a diameter ratio D _I / D _A of 0.5 to 0.8 with its outer diameter D _A. vibration according to the claims 1 and 2, characterized in that the spherical particles of the granules have a diameter of 2.5 mm to 3.5 mm. vibration according to the claims 1 to 3, characterized in that it is in the granules to a plastic granules, in particular POM (polyoxymethylene) or ABS (acrylonitrile-butadiene-styrene copolymer) or ASA (acrylic ester-styrene-acrylonitrile), is. Vibration damper according to one of the preceding claims, characterized in that the plunger ( 20 ) has a conical or spherical stamp shape. Swiveling linkage of a flap or lid to a motor vehicle with a between the flap and the lid and a bodywork component of the motor vehicle arranged damping and spring element, characterized in that the damping element as a vibration damper is formed according to one of the preceding claims. vibration according to claim 6, characterized in that the spring element in parallel to the damping element is arranged.