DE202005020820U1 - fluid damper - Google Patents

Abstract

Fluid damper, in particular for mobile Furniture parts, with a guided in a cylinder relative to cylinder displaceable piston, wherein in the piston and / or between Piston and cylinder is provided at least one throughflow for fluid flowing through, characterized in that above a threshold of a Pressurization on the fluid damper (19) at least one overload opening (10) in the piston (2, 2 ') and / or between the piston (2, 2') and cylinder (1) can be opened is.

Description

The The present invention relates to a fluid damper, in particular for movable Furniture parts, with one guided in a cylinder relative to the cylinder displaceable piston, wherein in the piston and / or provided between the piston and cylinder at least one flow opening for fluid flowing through is.

Fluid damper are in the prior art in various forms of training and applications known. Among other things, they are connected with movable furniture parts used. Thus, with corresponding fluid dampers e.g. the closing movement be dampened by furniture doors, with a loud slamming and possible damage the doors are prevented. The damping effect the fluid damper is based essentially on the flow resistance of a cylinder existing fluid. Upon pressurization of the piston this is shifted relative to the cylinder, wherein the fluid through flow openings through through the piston or between the piston and cylinder of a Cylinder chamber flows into another. Instead or as well additional for damping effect by means of flow resistance can also be provided by friction energy reduction.

at the known in the prior art fluid dampers occurs when this be subjected to excessive pressure, so-called damper bounce. In this situation, the fluid can no longer sufficiently on the piston pass by or through the piston. The increased pressure is then no longer through the damper degraded, so that the piston or the attached piston rod abruptly stops or springs back.

task The present invention is to improve a fluid damper in that the described damper bounce effective at overload is prevented.

This is achieved according to the invention, by above a threshold value of a pressurization the fluid damper at least one overload opening in the Piston and / or between the piston and cylinder can be opened.

It Thus, it is provided that from a certain threshold of Pressurization on the fluid damper or on its piston rod or the piston overload openings open be, by the addition to and / or instead of the flow through fluid through the piston through and / or past the piston, causing a too strong Increase of the braking force and thus the unwanted damper bouncing is prevented. In such Ab abuse or overload situation is through the open overload openings heavy pressure reduction possible. The respective threshold value of the pressurization can be determined by a person skilled in the art depending on the field of application by appropriate choice of the shape and size of the overload openings, the wall thicknesses used and the materials are determined.

Cheap for one optimal pressure reduction in case of overload is when the overload opening is off the threshold value of the pressurization with further increasing pressurization on the fluid damper, preferably continuously, further openable. Preferably the fluid damper according to the invention as linear damper educated. Very cheap can the type of the invention Protection against overload with fluid dampers be used, the damping effect essentially on the flow resistance of the fluid is based. The fluids include both gases, e.g. Air, as well as liquids or hydraulic fluids, such as. oils in question. Preferred embodiments see the use of fluid damper according to the invention in moving furniture parts like doors, Schubladeneinzügen or hinges, in particular furniture hinges, in front.

Further Advantages and details of the present invention will become apparent from the following description of the figures. Showing:

The 1 to 3 a first embodiment according to the invention,

the 2a and 3a Details from the 2 and 3 .

the 4 and 5 Top views of the piston of the first embodiment from direction AA (see 2 and 3 )

the 6 to 8th a second embodiment according to the invention,

the 7a and 8a Details from the 7 and 8th .

the 9 the second embodiment in an overload situation,

the 10 a furniture hinge with inventive fluid damper,

the 11 a schematic representation of the course of the closing movement of a furniture door with inventive fluid damper,

the 12 such as 12a and 12b a third embodiment according to the invention,

the 13 such as 13a and 13b A fourth embodiment according to the invention,

the 14 such as 14a to 14d A fifth embodiment according to the invention,

the 15 such as 15a to 15d a sixth embodiment according to the invention and

the 16 to 18a a special shape and design of flow openings.

At the fluid damper 19 according to the embodiments, the piston 2 , as known per se, displaceable in a cylinder 1 guided. The pressurization on the piston 2 done by means of the piston rod 5 , The return spring 6 essentially serves to return the piston 2 following a steaming process. In the latter case, the piston is pressurized by the piston rod 5 in the direction 23 in the cylinder 1 pushed.

The absorber 7 is made of a slightly compressible material such as sponge rubber. It serves to adjust the volume of the piston rod 5 if these are in the direction 23 in the cylinder 1 is pushed into it. The seals 8th and 9 may be embodied in any manner known in the art. They only prevent the unwanted leakage of the inside of the cylinder 1 arranged fluids and thus an unwanted pressure drop. On the piston 2 is in the first embodiment according to the 1 to 5 a ring-shaped or tubular closure element 3 arranged. This is longitudinal and extends on the piston 2 slidably mounted relative to this. The closure element 3 met in the present embodiment as well as in the variant according to 6 to 9 a double function. On the one hand, the flow opening 4 when pressure is applied to the fluid damper 19 or its piston rod 5 reduced in their flow area. On the other hand, the closure element opens 3 how in detail on the basis of 3 . 3a . 4 and 5 shown, in case of overload, the overload openings 10 which in the piston 2 are arranged. To perform this dual function, is the closure element 3 formed radially expandable. When pressurized, the closure element can 3 thereby in the direction of the wall of the cylinder 1 expand, bringing the annular and between closure element 3 and inner wall of the cylinder 1 arranged flow opening 4 reduced in its cross-section and thus the flow resistance of the fluid is increased.

To explain the overload protection according to the invention is with respect to this embodiment in particular to the 3 . 3a . 4 and 5 directed. The 4 shows a view from direction AA on the piston 2 in the in 2 illustrated normal operating situation in which the pressurization is below the threshold and the fluid through the annular gap 4 can flow through it. 5 shows the view on the piston 2 from direction AA in the in 3 illustrated overload situation. 3a shows the in 3 Area marked with a circle in an enlarged view. In normal operation, in which the pressurization is less than the predetermined threshold, fluid between the closure element 3 and the wall of the cylinder 1 through the flow opening 4 flow, causing the piston 2 inside the cylinder 1 is displaceable. By increasing the pressurization, the annular shutter member becomes 3 radially expanded, causing the flow-through 4 is reduced in size in its cross section. The dimensioning of the piston 2 with the tapered from the piston exterior to the piston interior overload openings 10 and the inside diameter of the cylinder 1 as well as the wall thickness and the material properties of the closure element 3 are selected so that upon reaching the intended for the particular application of the fluid damper threshold by increasing expansion of the closure element 3 the overload openings 10 in the area 12 be opened so that fluid can flow through them. As a result, blocking or bouncing of the piston is prevented in the case of excessive pressurization. In the 5 shown overload situation is in 3a shown again in a sectional view.

In addition to the pressure-dependent control of the flow cross-section and thus the flow resistance of the fluid by stretching the closure element 3 In all embodiments, additionally a path-dependent control of the flow resistance is realized. For this purpose, it is provided that the inner diameter of the cylinder in the region in which the piston is displaceable, so for example in the areas 11a . 11b . 11c and 11d , varies in size. Due to the tapering of the inner cylinder diameter in the direction of the cap 8th becomes the flow-through opening 4 with increasing impressions of the piston 2 in the cylinder 1 in the direction 23 reduced. As a result, the flow resistance of the fluid is automatically higher, the farther the piston rod 5 or the piston 2 in the cylinder 1 is inserted. 1 shows the first embodiment in the situation in which the piston rod 5 essentially no pressure is exerted. 1 also shows the relative position of pistons 2 and closure element 3 at the return of the piston by means of the spring 6 against the direction 23 , In the reset situation shown is a relatively large Gap between the closure element 3 and the piston 2 free. This allows a good flow through the fluid and thus a quick return. In 2 the reduction of the cross-section of the flow-through opening takes place in the transition between the regions 11b and 11c ,

In the second embodiment of the invention according to the 6 to 9 are in the piston 2 ' additional flow openings 4 ' arranged. The annular closure element 3 ' is not relative to the piston in this embodiment 2 ' slidable, but engages in a groove eighteen in the piston. The closure element 3 ' is as in the first embodiment radially expandable, so that the flow openings 4 , as already described, in its opening cross-section pressure-dependent by the closure element 3 ' can be controlled. Another pressure-dependent control of the total flow cross section is in this example by the interaction of the brake disc 15 with the cover plate 16 given. Both slats are slidable to each other and to the piston 2 ' on a connecting rod 14 stored, which the piston 2 ' with the connecting element 13 combines. The piston 2 ' is over said connection bar 14 and the connecting element 13 against the spring 6 supported, which performs the same function as in the first embodiment.

The pressure-dependent control takes place in this embodiment in the interaction of the slats 15 and 16 with the pressure-dependent expansion of the closure element 3 ' , As a result, this results in a constant control of the braking force or damping of the fluid damper 19 achieved for different closing forces. These change, for example, by aging of the closing mechanisms, such as the hinges, or vary by the use of different hinge types. The slats 15 and 16 can be made so fine or smooth that they react to low pressures, which particularly well changes in the closing force can be compensated. The closure element 3 ' is then conveniently designed so that it can respond to larger pressure changes.

6 shows the second embodiment, when the piston rod 5 by means of the spring 6 has been fully extended. The overflow openings 4 ' and 4 are maximally open in this situation. Now pressure on the piston rod 5 in the direction 23 exercised, so puts the brake disc 17 by moving along the connecting rod 14 first to the piston 2 ' at least partially closes the flow openings 4 ' , The brake disc 15 has at least one slat opening 17 which is arranged so that fluid still through the slat opening 17 and at least a part of the flow-through opening 4 ' can flow. If the pressure builds up further, the cover lamella becomes 16 also in the direction of the piston 2 ' moved and with appropriate pressure, as in the 7 . 7a . 8th and 8a shown, deformed. Depending on the degree of deformation is thereby the slat opening 17 partially or completely closed. At the same time takes place by the pressure buildup and an elongation of the annular closure element 3 ' , which in turn causes the outer annular flow opening 4 is tapered in its opening cross-section.

If the pressurization increases over a threshold value provided for the respective area of application of the damper, the overload protection according to the invention also occurs in this exemplary embodiment by opening the overload opening 10 , which in this embodiment in the region of the groove eighteen is executed. The overload situation is in 9 shown. The closure element 3 ' is by appropriate pressure build-up in the groove eighteen stretched so far that the overload opening 10 is opened, whereby the fluid again a way to flow past the piston 2 ' given is. In this case, the closure element 3 ' through an in 9 invisible support so in its position relative to the piston 2 ' held that no relative displacement between closure element 3 ' and pistons 2 ' is possible, and the closure element after completion of the overload situation back into the groove eighteen locks.

In the first two embodiments according to the 1 to 9 fulfills the closure element 3 respectively. 3 ' a double function. On the one hand, it controls the opening and closing of the overload opening (s) 10 , On the other hand, the closure element also controls the flow cross section of the flow openings 4 ,

In the now described in the following further embodiments of the invention according to the 12 to 15d these two functionalities are separated from each other. For opening and closing the overload opening (s) 10 is at least one overload control device 28 intended. For changing the flow cross section of the flow openings 4 points the fluid damper 19 a flow-through control element 24 on. The overload control device 28 and the flow-through control element 24 are separate - different - components of the fluid damper 19 ,

The flow-through control element 24 essentially has the features of the closure element 3 . 3 ' the first two embodiments or may be formed accordingly. In particular, it is provided that said element 24 is stretchable, so the closure cross section of the flow openings 4 with increase on the fluid damper 19 effective pressurization by the flow control element is reduced. Conveniently, this is like the closure elements 3 . 3 ' ring-shaped or tubular and radially expandable. In addition, it can also be provided that the Durchströmöffnungskontrollelement 24 extends longitudinally and preferably along its longitudinal extent has different wall thicknesses. In the embodiments according to the 12 to 15d is the element 24 also between a stop 27 on the piston 2 and a stop of the respective connecting element 13 slidably mounted in the cylinder longitudinal direction.

In the 12 to 12b is a first variant of the flow-through control element 24 separated overload control device 28 shown, in which this essentially a spring-loaded ball 25 having. This is intended to overload the opening 10 as long as the pressurization in the fluid is below a predefinable threshold. Is this by the properties of the ball stressing spring 26 predetermined threshold exceeded, it comes to the deflection, preferably for compression, the spring 26 , whereby the overload opening 10 released and the fluid a way through the piston 2 is opened through. 12a shows the section 34 out 12 in case of overload, where the ball 25 the overload opening 10 releases. 12b shows the same detail in the normal state where the ball 25 acted upon by the spring 26 , the overload opening 10 closes. In this embodiment, the ball 25 stressing spring 26 parallel to the direction of movement of the piston displaceable in the cylinder 2 deflectable.

In the embodiment according to the 13 to 13b is also a resilient variant of the overload control device 28 intended. However, this is deflected in the radial direction. In embodiments of this type, the overload control means for opening and closing the overload opening 10 a resilient ring or, preferably c-shaped, resilient ring segment 29 on. This closes in normal operation with the cap 30 the overload opening 10 in the piston 2 , Only when a through the elastic properties of the ring segment 29 (or rings) predetermined threshold value of the pressurization is exceeded, the ring segment 29 stretched so far that the overflow 10 is released and fluid through it and on the piston 2 can flow past. This situation is in the clipping 35 in 13a shown. 13b indicates in an exploded view that the resilient ring segment 29 the piston 2 partially covered, wherein the overload opening 10 in the lateral surface of the piston 2 is arranged.

In the fifth embodiment according to the invention 14 to 14d has the overload control device 28 an eccentrically stretchable ring 31 on. This is in the illustrated embodiment, as particularly well in 14b can be seen with a catch 32 equipped, which is intended, in the recording 33 of the piston 2 to be anchored. This is the eccentric stretchable ring 31 only in sections or only in a small portion of the piston 2 fixed. When pressurized, it comes through this one-sided fixation to an eccentric strain of the ring 31 , If the predefinable threshold value is exceeded, the corresponding in 14d illustrated overload opening 10 in the piston 2 free, which in turn causes fluid on the piston 2 can flow past. 14c shows the same view from the direction 37 on the piston 2 However, in the situation where the pressurization on the eccentric stretchable ring 31 is below the threshold and the overload opening 10 through the ring 31 is closed. 14a shows the detail 36 from the sectional view 14 , In the situation shown here is the overflow 10 through the eccentrically stretchable ring 31 locked.

The 15 to 15d show a further embodiment of the invention, in which the overload control device 28 a preferably disc-shaped overload lamella 38 which, in turn, opens and closes in the piston 2 provided overload openings 10 at least one elastically deformable region 39 having. The or the areas 39 are of, preferably substantially V-shaped or U-shaped recesses 41 partially surrounded. The tabs thus formed can be bent with appropriate pressurization and thus open the overload openings 10 , which in turn causes fluid through the piston 2 can flow through it. The overload lamella 38 is like this on the basis of the detailed representations 15b to 15d of the clipping 40 can be seen, parallel to the direction of movement of the piston 2 axially displaceable stored on this. 15b shows the situation where the overload lamella 38 from their stop on the piston 2 is removed. 15c shows the situation when they are on the piston 2 but abuts the overload opening 10 not yet released. In 15d are the deformable areas 39 bent over after exceeding the threshold value of the pressure load and the overload opening (s) 10 is (are) released.

For path-dependent damping is in the already shown and discussed embodiments, the interaction of the closure element 3 . 3 ' or Durchströmöffnungskontrollele mentes 24 with the preferably variable inner diameter of the cylinder 1 intended. The 16 to eighteen moreover show a variant in which for the control of the flow cross section in addition, preferably substantially parallel to the direction of movement of the piston extending, substantially groove-shaped flow openings 42 are provided. This can both in the piston 2 facing inner wall of the cylinder 1 as well as in the piston 2 and / or in the flow-through control element 24 or in the closure element 3 . 3 ' be arranged.

As the 16 to 18a show is also in the substantially groove-shaped flow openings 42 preferably provided that they vary their flow cross-section in the longitudinal direction of the cylinder. So shows 16a the cross section in the in 16 illustrated position in which the piston is at the beginning of the damping movement. Will the piston rod 5 and so that the piston pushed further, it comes in the 17 and 17a already shown to a change in both the groove-shaped flow openings 42 as well as the annular flow opening 4 , In the in eighteen and 18a illustrated situation in which the piston rod 5 is almost completely inserted into the cylinder, the annular flow openings 4 completely closed. In this area are also no groove-shaped flow openings 42 provided more in the cylinder inner wall. Open are still only the groove-shaped flow openings 42 in the flow-through control element 24 , The variant shown with the additional groove-shaped flow openings 42 is possible in all shown and previously discussed embodiments. It allows the curvature cross-section available in the respective position of the piston to be particularly strong over the longitudinal extension of the cylinder 1 to vary. So this is a cheap further variant of the damping properties of the fluid damper path-dependent to make.

The relationship between pressurization and elongation can be selected by material selection and appropriate dimensioning of the closure element 3 respectively. 3 ' or the overload control device 28 and the flow-through control element 24 be achieved. For example, a quadratic relationship is preferred in which the change in strain per pressure change decreases with increasing pressurization. Cheap materials for the production of the closure element are thermoplastics and / or elastomers, such as TPE's (thermoplastic elastomers). By varying or varying wall thicknesses of said components, a desired variation of the expansion behavior can additionally be achieved. Thus, it can be provided both that the components expand in some areas more than in others or evenly over their entire longitudinal extent.

10 shows a furniture hinge 20 as an application form on which a fluid damper according to the invention 19 is arranged. This one is on the hinge arm here 22 placed. The piston rod is supported on the opposite side.

11 schematically shows the closing behavior of a door, with a furniture hinge with inventive fluid damper 19 Is provided. In the diagram shown, the speed of movement v of the door is plotted against the opening angle α. The phases I to IV of the closing process are differentiated. In phase I (up to a closing angle of approx. 20 °), the fluid damper is not in action. In Phase II, there is a gentle first braking and interception of the door. In phase III, the essential braking process is ensured by an interaction of the above-described pressure-dependent and path-dependent damping. In area IV, the door speed is already slowed to almost zero. There is a gentle closing.

Claims (36)

Fluid damper, in particular for movable furniture parts, with a guided in a cylinder relative to the cylinder piston, wherein in the piston and / or between the piston and cylinder at least one flow opening is provided for fluid flowing through, characterized in that above a threshold of pressurization of the fluid damper ( 19 ) at least one overload opening ( 10 ) in the piston ( 2 . 2 ' ) and / or between pistons ( 2 . 2 ' ) and cylinders ( 1 ) is openable. Fluid damper according to claim 1, characterized in that the overload opening ( 10 ) From the threshold value of the pressurization with further increasing pressurization of the fluid damper, preferably continuously, is further openable. fluid damper according to claim 1 or 2, characterized in that its damping effect essentially on the flow resistance of the fluid is based. fluid damper according to one of the claims 1 to 3, characterized in that it is a linear damper. Fluid damper according to one of claims 1 to 4, characterized in that the cylinder ( 1 ) has at least two different inner diameters in the region in which the piston ( 2 . 2 ' ver slidable. Fluid damper according to one of claims 1 to 5, characterized in that the flow-through opening ( 4 . 4 ' ) in its flow cross-section with increase of the fluid damper ( 19 ) acting pressurization by at least one closure element ( 3 . 3 ' ) is reducible. Fluid damper according to claim 6, characterized in that the closure element ( 3 . 3 ' ) is annular or tubular. Fluid damper according to one of claims 6 or 7, characterized in that the closure element ( 3 . 3 ' ) is radially expandable. Fluid damper according to one of claims 6 to 8, characterized in that the closure element ( 3 . 3 ' ) is longitudinally extending and preferably along its longitudinal extent has different wall thicknesses. Fluid damper according to one of claims 6 to 9, characterized in that with increasing pressurization in its cross-section reducible flow-through ( 4 . 4 ' ) at least partially between closure element ( 3 . 3 ' ) and the inner wall of the cylinder ( 1 ) is arranged. Fluid damper according to one of claims 6 to 10, characterized in that the flow-through opening ( 4 ) at least partially between pistons ( 2 ) and closure element ( 3 . 3 ' ) is arranged. Fluid damper according to one of claims 6 to 11, characterized in that the closure element ( 3 . 3 ' ), preferably on the piston ( 2 ), relative to the piston ( 2 ) is slidably mounted. Fluid damper according to one of claims 6 to 11, characterized in that the overload opening ( 10 ) in the form of a, preferably circumferential, groove ( eighteen ) in the outer surface of the piston ( 2 ' ) is formed and the closure element ( 3 ' ) in this groove ( eighteen ) intervenes. Fluid damper according to one of claims 1 to 13, characterized in that the overload opening ( 10 ) in the piston ( 2 ) is formed with the piston outer to the piston interior towards tapered opening cross-section. Fluid damper according to one of claims 1 to 14, characterized in that at least one, preferably additional, flow-through opening ( 4 ' ) in the piston ( 2 ' ) is provided, which by at least one brake disc ( 15 ) when pressure is applied to the fluid damper ( 19 ) is partially closed. Fluid damper according to claim 15, characterized in that the brake disc ( 15 ) at least one slat opening ( 17 ), which is arranged so that fluid through the slat opening ( 17 ) of the brake disc ( 15 ) and the flow-through opening ( 4 ' ) can flow. Fluid damper according to one of claims 15 or 16, characterized in that a cover lamella ( 16 ) is provided, which the slat opening ( 17 ) of the brake disc ( 15 ) depending on the pressurization on the fluid damper ( 19 ) closes differently. Fluid damper according to one of claims 15 to 17, characterized in that the brake disc ( 15 ) with the slat opening ( 17 ) relative to the piston ( 2 ' ) is movably mounted. Fluid damper according to one of claims 15 to 18, characterized in that the cover plate ( 16 ) relative to the piston ( 2 ' ) and / or to the brake disc ( 15 ) is movably mounted. Fluid damper according to one of claims 6 to 19, characterized in that the closure element ( 3 . 3 ' ) the overload opening ( 10 ) opens above the predetermined pressurization. Fluid damper according to one of claims 1 to 5, characterized in that it is used for opening and closing the overload opening ( 10 ) at least one overload control device ( 28 ) and for changing the flow cross-section of the flow opening ( 4 . 4 ' ) at least one flow-through control element ( 24 ) having. Fluid damper according to claim 21, characterized in that the overload control device ( 28 ) and the flow-through control element ( 24 ) are different components of the fluid damper. Fluid damper according to claim 21 or 22, characterized in that the flow-through control element ( 24 ) the features of the closure element ( 3 . 3 ' ) according to at least one of claims 6 to 12. Fluid damper according to one of claims 21 to 23, characterized in that the overload control device ( 28 ) a spring-loaded ball ( 25 ), wherein the ball ( 25 ) is provided, the overload opening ( 10 ) and the ball ( 25 ) loading spring ( 26 ) from reaching the threshold of a pressurization so deflectable, preferably compressible, is that the ball ( 25 ) the overload opening ( 10 ) releases. Fluid damper according to claim 24, characterized in that the ball ( 25 ) loading spring ( 26 ) parallel to the direction of movement of the displaceable piston in the cylinder ( 2 ) is deflectable. Fluid damper according to one of claims 21 to 23, characterized in that the overload control device ( 28 ) for opening and closing the overload opening ( 10 ) a resilient ring or a, preferably c-shaped, resilient ring segment ( 29 ) having. Fluid damper according to claim 26, characterized in that the resilient ring or the resilient ring segment ( 29 ) the piston ( 2 ) optionally partially, and preferably the overload opening ( 10 ) in the lateral surface of the piston ( 2 ) is arranged. Fluid damper according to one of claims 21 to 23, characterized in that the overload control device ( 28 ) an eccentrically stretchable ring ( 31 ) having. Fluid damper according to claim 28, characterized in that the eccentrically extensible ring ( 31 ), preferably by means of a latching nose ( 32 ), only in sections, preferably only in a small partial area, on the piston ( 2 ) is fixable. Fluid damper according to one of claims 21 to 23, characterized in that the overload control device ( 28 ), preferably disc-shaped, overload lamella ( 38 ), which for opening and closing the overload opening ( 10 ) at least one elastically deformable region ( 29 ) having. Fluid damper according to claim 30, characterized in that the elastically deformable region ( 39 ) partially of a, preferably substantially V-shaped or U-shaped, recess in the overload lamella ( 38 ) is surrounded. Fluid damper according to claim 30 or 31, characterized in that the overload plate ( 38 ) parallel to the direction of movement of the piston ( 2 ) is slidably mounted. Fluid damper according to one of claims 1 to 32, characterized in that an optionally present closure element ( 3 . 3 ' ) or an optional flow-through control element ( 24 ) and / or the piston ( 2 ), preferably in the outer circumferential surface facing the cylinder, at least one, preferably substantially parallel to the direction of movement of the piston ( 2 ) extending, substantially groove-shaped flow opening ( 42 ) having. Fluid damper according to one of claims 1 to 33, characterized in that in the piston ( 2 ) facing inner wall of the cylinder ( 1 ) at least one, preferably substantially parallel to the direction of movement of the piston ( 2 ) extending, substantially groove-shaped flow opening ( 42 ) is provided. Fluid damper according to claim 33 or 34, characterized in that the substantially groove-shaped flow opening ( 42 ) has at least two areas with different opening cross-sections (have). Hinge, in particular furniture hinge ( 20 ), with a fluid damper ( 19 ) according to one of claims 1 to 35.