DE8130523U1 - Two-tube vibration damper for receiving managers, especially in motor vehicles - Google Patents

Description

Two pipe vibration dampers to accommodate executives, especially in motor vehicles

The invention relates to a twin-tube vibration damper to accommodate executives, especially in motor vehicles, with a damping fluid filled, one-piece cylinder tube enclosing a working space in which one generating damping forces and one after piston rod attached to the outside protruding piston rod is guided, one under the cylinder tube Formation of a compensating space surrounding the jacket pipe, whereby the compensation space is filled with gas and damping liquid and via bottom valves is in connection with the working space, as well as with a working pipe that closes off at the top, hydraulic cable stop and ring, which in the rest position by means of a spring at a distance from the upper End of the cylinder tube are held and a passage opening and gaps for the damping fluid to generate a damping force Has a radially projecting ring web attached to the piston rod.

Two-tube vibration damper of the type mentioned above with an inner cylinder tube and an outer jacket tube have long been known. The cylinder tube is equipped with a damping

filled with liquid and includes the working space in which the working piston that generates damping forces is led. The working space is the same as that formed by the cylinder tube and jacket tube Compensation chamber connected via bottom valves, with the compensation chamber in the lower area with Damping liquid and filled with gas in the upper area. The working piston is on one Fastened piston rod, the top of the cylinder tube closed with a cover is led out.

So that executives can still be transferred in the rebound state, the piston Do not extend the rod too far out of the cylinder barrel. The support would then be insufficient. To the Limiting the extension stroke of the piston rod and thus of the working piston is the case with the known twin-tube vibration dampers one arranged at a sufficient distance from the upper end of the cylinder tube Cable stop provided on which the piston itself or an annular web arranged above the piston can strike.

For reasons of installation, these vibration dampers often have a small radial dimension, so that in particular in the presence of a piston diameter that is relatively large compared to the outer diameter of the damper little space for a sufficiently large reserve or *

Gas space remains.

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To solve this problem, an embodiment was proposed in DE-GM 19 9o 1o2 which the cylinder tube only includes the part of the working space that is used for the stroke. Its upper limit is formed by a cover through which the piston rod goes. This cover forms at the same time the mechanical rebound stop against which the working piston strikes in the rebound stage. The lid will supported by a support tube that tightly encloses the piston rod at the upper end of the jacket tube.

Due to the fact that the diameter is much smaller than that of the cylinder tube, the result was a considerable increased space for the gas in the equalization chamber, so that with the same damping properties can achieve a significantly smaller outer diameter. Similar trainings also show the DE-GM 76 06 64o and 76 19 54o.

In order to reduce the cornering tendency of a vehicle, twin-tube vibration dampers have recently been used provided with hydraulically damped cable stops. These stops are no longer fixed to the inner tube connected, but formed like an annular piston, being in the intended rest position by a spring being held. The cable stops have openings or gaps through the damping fluid can pass if the working piston or one attached to the piston rod Ring web strikes against it.

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However, no one saw a possibility of this type of cable connection in the twin-tube dampers used up to that point to be integrated with the support tubes of small diameter. One therefore went back to a continuous cylinder tube and accepted the disadvantage that to achieve the same. Compensation room volume larger diameter had to be provided for the jacket pipe.

The invention is based on the object, in the case of a two-tube vibration damper, of the type mentioned at the beginning Kind of a solution to avoid the aforementioned disadvantages ΐαεεεη, in particular how, despite the use of a hydraulic cable stop, a smaller radial extension of the Realize damper with the same compensation and working space volume.

According to the invention, this object is achieved by that the cable stop and ring are within a retracted range in terms of diameter of the cylinder tube sits and the ring web to act on the cable stop, and ring in one the maximum possible evasive movements of the cable stop and ring corresponding to the distance to the working piston is arranged and a foot diameter corresponding to the inner diameter of the drawn-in area having,.

The hydraulic cable stop is therefore according to the invention in a drawn-in with regard to the diameter

NEN area of the cylinder tube arranged so that - as in the embodiments with the Support pipe - with the same jacket pipe diameter, the compensation space is increased. this conversely means that the twin-tube vibration damper according to the invention with the same compensation space volume can be built with a smaller jacket pipe diameter. This is the first time the combination a hydraulic cable stop with a small radial extension of the jacket tube succeeded, whereby this is done with particularly simple means. The change in diameter can namely can also be produced by hammering, which has the advantage that the diameter transition step can be made very steep or short in a space-saving manner. Also is with With this manufacturing process, the required low coaxiality and misalignment of the two cylinder tube diameters guaranteed.

In an embodiment of the invention it is provided that in the rest position of the cable stop and ring Grooves extending in the axial direction are provided on the inside of the cylinder tube. Through this the damping forces are reduced at the beginning of the evasive movement and the impact is softened. Preferably, the depth and / or width of the grooves should gradually decrease towards the top, by one continuous transition up to the maximum

To achieve damping forces.

The drawn-in area of the cylinder tube and the grooves are advantageously drawn or hammered.

Finally, the invention provides that the diameter of the retracted area of the cylinder tube taking into account the space requirements of the ./6

• · · · a ti - Cable stop if possible ■ · t
Il I for is Ί , around as large as possible ■ ■ III the The end- to achieve the same space 6 - small amount Gain of space •

In the drawing, the invention is based on an exemplary embodiment shown in a schematic section illustrated in more detail. It shows a twin-tube vibration damper 1, its external shape is formed by a jacket tube 2, at the lower part of which a stub axle 3 is attached is.

A cylinder tube 4 is arranged on the inside coaxially to the casing tube 2, with between the two tubes 2, 4 a compensation space is formed, the upper part of which with gas 5 and the lower part with Damping fluid 6 is filled. The cylinder tube 4 is completely filled with damping fluid 6 filled and is closed at the top by a lid 7.

In the cylinder tube 4, a damping force is generated Working piston 8 out of the lower End of a piston rod 9 is attached. The piston rod 9 is led out of the cover 7 upwards, where a seal 7a prevents losses of damping fluid 6 and gas 5. The cover 7 is used together with the working piston 8 of the guide Piston rod 9.

The cylinder tube 4 encloses the working space 11 for the working piston 8 in the lower area 1o. The upper Area 12 of the cylinder tube 4 is on a much smaller diameter compared to the lower area Io drawn in, with between

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two areas Ιο, 12 a conical transition area 13 is present. In this way, the cross-sectional area of the compensation space increases between inner tube 4 and jacket tube 2, which has the consequence that an equal equalizing space volume with a lower Diameter of the jacket tube 2 can be realized.

Immediately above the transition area 13 there is a tension stop designed in the manner of an annular piston 14, which is held there in the rest position via a helical spring 15 supported on the cover 7 will. An additional ring 16 has an opening that allows damping fluid to pass through 6 allowed if he. is moved against the action of the coil spring 15 upwards. in the The region of the rest position is also axially extending and downwardly open in the cylinder tube 4 Grooves 17 are formed, which also allow damping fluid 6 to flow past in this area.

An annular web 18 is attached to the piston rod 9 at a distance from the working piston 8, the outer diameter is smaller than the inner diameter of the upper region 12 of the cylinder tube 4. When extending the piston rod 9 can therefore move into the upper region 12 and then push against it the cable stop 14 and Ritig 16. These give way upwards against the action of the helical spring 15 below Generation of damping forces, with damping fluid passing through the opening in the ring 16 and grooves 17 flows into the working space 11. These damping forces increase at the upper end of the Grooves 17 more and more, since their cross-section is smaller towards there and they finally end completely, so that

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only the opening of the ring 16 is available stands.

The maximum compensatory movement of the tension stop 14 is ended when the helical spring 15 opens Block goes. So that the working piston 8 then not collides with the cylinder tube 4 in the transition area 13 »is the distance between the working piston 8 and the annular web 18 are dimensioned larger than the maximum evasion path of the tension stop 14.

Claims (4)

Claims :
5 I. Twin-tube vibration damper (1) for accommodating executives, especially in motor vehicles, with a one-piece cylinder tube (4) filled with damping fluid (6) and enclosing a working space (11) in which a piston rod (9 ) attached working piston (8) is guided, a jacket tube (2) surrounding the cylinder tube (4) to form a compensation space, the compensation space being filled with gas and damping fluid (5, 6) and via bottom valves with the working space (11) in Is connected, as well as with a hydraulic cable stop (14) and ring (16) which closes the working space at the top and which are held in the rest position by means of a spring (15) at a distance from the upper end of the cylinder tube (4) and a passage opening and gap (17) for the damping fluid (6) to generate a damping force when a radially protruding ring web (1 8), characterized in that
that the cable stop (14) and ring (16) are seated within an area (12) of the cylinder tube (4) that is retracted in terms of diameter, and the ring web (18) for acting on the cable stop (14) and ring in one of the maximum possible evasive movement of the cable stop (14) and ring (16) is arranged at a corresponding distance from the working piston (8) and · _! ·· * · irt M - 1o - an outer diameter corresponding to the inner diameter of the drawn-in area (12) having 2. Two rohrschwi ngungsdänipf he according to claim 1, characterized in that that in the rest position of the cable stop (14) and ring (16) extending in the axial direction and downwardly open grooves (17) on the Inside of the ZyIinderrohrs (4) are provided. 3. Two-tube vibration damper according to the claims 1 to 2, characterized, that the retracted area (12) of the cylinder tube (4) and the grooves (17) drawn or hammered are. 4. Two-tube vibration damper according to one of the claims 1 to 3, characterized, that the diameter of the retracted area (12) of the cylinder tube (4) taking into account the space required by the cable stop (14) is as small as possible.