Damping device for a movable furniture part

Abstract

Damping device (11) for a movable furniture part, with at least one damper (12) which has a damper element (13) that can be coupled to the movable furniture part, the kinetic energy of which is transmitted by the movable furniture part can be damped by means of a damping fluid located in the damper (12), wherein the damping fluid comprises at least one damping liquid and at least one emulsifier mixed with the damping liquid, characterized in that the damping fluid is a dispersion, with the damping liquid as the dispersion medium and air as the dispersed phase, wherein the added emulsifier ensures a constant dispersion of the air bubbles (24) in the liquid.

Description

[0001] The invention relates to a damping device for a movable furniture part, comprising at least one damper which has a damper element that can be coupled to the movable furniture part, the kinetic energy of which is transmitted by the movable furniture part and can be damped by means of a damping fluid located in the damper, wherein the damping fluid comprises at least one damping fluid and at least one emulsifier mixed with the damping fluid.

[0002] Damping devices for movable furniture parts have been known for a long time. They are primarily used to prevent the movable furniture part from striking the furniture body hard when moving into the closed and / or open position. One such damping device is known, for example, from DE 10 2008 005 463 A1. The damping device disclosed therein serves to dampen the movement of a furniture flap moving into the closed position.

[0003] German patent application DE 10 66 452 A describes a liquid damping device for door closers, shock absorbers for motor vehicles, and the like. The damping fluid used in the shock absorber consists of an emulsion of water and oil.

[0004] DE 203 02 120 U1 discloses a liquid damper for use on movable furniture parts, comprising a cylinder, a piston linearly movable in the cylinder with a piston rod and an elastic displacement element, wherein the displacement element is designed as a slotted jacket surrounding the piston rod.

[0005] DE 600 10 202 T2 discloses a hydraulic shock absorber with a piston that divides the interior of a cylinder into an expansion-side oil chamber and a compression-side oil chamber. A throttling device is provided for connecting the two oil chambers.

[0006] WO 2007 / 129 157 A2 describes a fluid damper comprising a cylinder in which a piston is movably guided. A guide sleeve is provided for guiding the piston, the guide sleeve being designed to allow fluid to flow into the space between the stem and the inside of the cylinder, where an elastic material is arranged.

[0007] In DE 20 2006 003 197 U1, a damper for furniture is described, with a housing in which a piston connected to a piston rod is slidably received, wherein a fluid flows through a flow channel on or in the piston when the piston moves within the housing, wherein a different damping force is obtained when the piston moves in different directions, and wherein the cross-section of the flow channel can be changed in certain areas by making the piston movable relative to a plate.

[0008] DE 482 802 A describes a process for producing fluid for hydraulic shock absorbers, using an oil-water emulsion as the fluid.

[0009] DE 10 2005 013 413 A1 describes a gas spring with a compensation chamber filled with a compensation medium whose volume changes and whose volume change causes a corresponding volume change of the working chamber.

[0010] A crucial component for the damping behavior of a damping device is the damping fluid. If hydraulic oil is used as the damping fluid, for example, care must be taken to ensure that the hydraulic oil contains as little gas, especially air, as possible. Gas, particularly air, can cause a drop in the damping device's performance during the damping process, meaning that reliable damping is not always guaranteed. Furthermore, it can generate unwanted noise during the damping process. This problem is exacerbated by the fact that small gas / air bubbles can merge over time to form a larger gas / air bubble, further amplifying the effects described above.

[0011] The object of the invention is to create a damping device for a movable furniture part of the type mentioned above, whose damping behavior remains essentially constant even after a large number of damping processes and in which disturbing noises during the damping process are avoided.

[0012] This problem is solved by a damping device having the features of independent claim 1. Further developments of the invention are described in the dependent claims.

[0013] The damping device according to the invention is characterized in that the damping fluid is a dispersion, with the damping fluid as the dispersion medium and air as the dispersed phase, wherein the added emulsifier ensures a constant dispersion of the air bubbles in the liquid.

[0014] Since it is generally unavoidable that a small amount of air is trapped in the damping fluid, it is necessary to prevent these air bubbles from coalescing into a larger bubble, which causes the aforementioned disadvantages. The added emulsifier prevents this, thus ensuring a consistent dispersion of the air bubbles in the fluid. The emulsifier therefore prevents the coalescence of the air bubbles.

[0015] An important characteristic of the emulsifier is that it should not contain any substances that are hazardous to health. Ideally, the emulsifier should be environmentally friendly, and in particular biodegradable. Preferably, the emulsifier should be essentially non-irritating. This is important because the damper usually remains installed in the associated furniture for an extended period, and therefore, any irritant exposure to people caused by outgassing of the emulsifier should be prevented.

[0016] In a particularly preferred configuration, the emulsifier comprises a surfactant. The surfactant can be, for example, derived from plant-based substances or, alternatively, from chemical substances. However, it is also possible for the surfactant to be predominantly plant-based or predominantly chemical, in each case potentially including additives. For instance, a mixture of plant-based and chemical surfactants is possible.

[0017] In a particularly preferred embodiment, the damper comprises a damper housing in which the damper element is slidably guided, the damper element dividing the interior of the damper housing into two chambers between which the damping fluid can flow back and forth during the damping process by means of at least one flow bridge. For example, at least one overflow channel formed in the damper element can serve as the flow bridge.

[0018] In a particularly preferred manner, the damper element is designed in a piston-like form and is connected to a piston rod which extends out of the damper housing, wherein a compensating volume is provided to compensate for the volume of the damping fluid displaced by means of the piston rod moving into the damper housing.

[0019] Advantageously, the compensating volume is formed by a molded part that can be compressed by the fluid pressure of the damping fluid. In a particularly preferred embodiment, the molded part is formed from a compressible solid foam.

[0020] The solid foam can be made of cellular rubber, for example. However, other types of solid foams can also be used.

[0021] In a further development of the invention, the solid foam is enclosed by at least one gas-permeable layer. This prevents the outgassing of gas, particularly air, contained in the solid foam.

[0022] The damping fluid is preferably oil, in particular hydraulic oil.

[0023] The invention further comprises a furniture fitting for a movable furniture part, characterized by a damping device according to one of claims 1 to 9.

[0024] The invention further relates to the use of a fluid provided with at least one emulsifier as a damping fluid in a damper of a damping device according to one of claims 1 to 9 for a movable furniture part.

[0025] Finally, the invention relates to the use of the damping device according to one of claims 1 to 9 in a furniture fitting on a drawer, door and / or flap.

[0026] A preferred embodiment of the invention is shown in the drawing and is explained in more detail below. The single figure in the drawing shows: a longitudinal section through a preferred embodiment of the damping device according to the invention.

[0027] The drawing shows a preferred embodiment of the damping device 11 according to the invention. The drawing shows, by way of example, one damper 12 of the damping device 11. However, it is possible for the damping device 11 to comprise several dampers 12. The damping device 11 is used with movable furniture parts. Examples of movable furniture parts include drawers, doors, or furniture flaps. The damping device 11 dampens the movement of the movable furniture part as it moves into the closed and / or open position. This is intended to prevent hard impacts against the furniture body when closing or opening.

[0028] The damper 12 has a damper housing 14 in which a damper element 13, which can be coupled to the movable furniture part, is slidably guided. According to the preferred embodiment, the damper element 13 is designed as a damper piston. The damper element 13 divides the damper housing 14 into two chambers 15, 16. An oil damper is used, with hydraulic oil being used as the damping fluid, by means of which the kinetic energy transmitted by the movable furniture part can be dampened.

[0029] As shown particularly in the drawing, the damper element 13 is connected to a piston rod 17 that extends from the damper housing. The piston rod 17 is fixedly held to a base part 18. Thus, the damper element is also fixed in position, and the damper housing 14 moves relative to it during the damping process. The damper housing 14 is pressed into the extended position shown in the drawing by means of at least one spring element 23, which acts on the base part 18 on one side and on the damper housing 14 on the other.

[0030] The damper 12 has an impact surface 19 which interacts with an actuation surface (not shown) of an actuation element arranged on the movable furniture part, on a fitting part of a furniture fitting, or on the furniture body. According to a preferred embodiment, the impact surface 19 is formed by the end face of the damper housing 14. The damping process is initiated by the contact between the impact surface and the actuation surface.

[0031] Hydraulic oil, hereinafter referred to as damper oil, is located in the damper housing 14 and flows back and forth between the two chambers 15, 16 during the damping process, with displacement taking place via flow bridges, one of which, an example of a transfer channel 20, is shown in the damper element 13.

[0032] During the damping process, the damper housing 14 is displaced relative to the damper element 13 and the piston rod 17, whereby damper oil is forced into the other chamber 16 via at least one transfer channel 20. Since both chambers 15 and 16 contain damper oil, and the damper oil is incompressible, an overflow and thus a movement of the damper housing 14 relative to the piston rod 17 and the damper element 13 can only occur if an equalization volume is created in the chamber 16 into which the damper oil is to flow. In this example, the equalization volume is formed by a molded piece made of solid foam, in particular cellular rubber, which can be compressed by means of the damper oil. The solid foam is closed-cell, so that damper oil cannot penetrate it. When the solid foam is compressed, an equalization volume is created, allowing damper oil to flow into the chamber 16.The fitting 21 is formed in the manner of a sleeve and is mounted on the piston rod 17.

[0033] To prevent gas trapped in the damper oil, especially air in the form of small air bubbles 24, from coalescing into a larger air bubble over time, an emulsifier is added to the damper oil. The emulsifier is a surfactant that prevents the air bubbles 24 from coalescing. To achieve this, the surfactant diffuses to the interface between the air bubbles and the damper oil and encapsulates the air bubbles. The surfactant is selected to ensure a sufficient spreading velocity, meaning that its propagation speed is optimized to guarantee a uniform surfactant distribution and complete encapsulation of all air bubbles 24.

[0034] The surfactant is preferably plant-based or, alternatively, chemically based. However, surfactant mixtures are also possible.

Claims

[1] Damping device (11) for a movable furniture part, comprising at least one damper (12) which has a damper element (13) which can be coupled to the movable furniture part, the kinetic energy of which is transmitted by the movable furniture part can be damped by means of a damping fluid located in the damper (12), wherein the damping fluid comprises at least one damping liquid and at least one emulsifier mixed with the damping liquid, characterized by , that the damping fluid is a dispersion, with the damping fluid as the dispersion medium and air as the dispersed phase, wherein the added emulsifier ensures a constant dispersion of the air bubbles (24) in the liquid. [2] Damping device (11) according to claim 1, characterized by that the emulsifier includes at least one surfactant. [3] Damping device (11) according to any one of the preceding claims, characterized by, that the damper (12) has a damper housing (14) in which the damper element (13) is slidably guided, wherein the damper element (13) divides the interior of the damper housing (14) into two chambers (15, 16) between which the damping fluid can flow back and forth during the damping process by means of at least one flow bridge. [4] Damping device (11) according to claim 3, characterized by , that the damper element (13) is designed in a piston-like manner and is connected to a piston rod (17) which is led out of the damper housing (14), wherein a compensating volume is provided to compensate for the volume of the damping fluid displaced by means of the piston rod (17) which moves into the damper housing (14). [5] Damping device (11) according to claim 4, characterized by , that the compensation volume is formed by a shaped piece (21) which can be compressed by means of the fluid pressure of the damping fluid. [6] Damping device (11) according to claim 5, characterized by, that the molded part (21) is formed by a solid foam. [7] Damping device (11) according to claim 6, characterized by that the solid foam is made up of cellular rubber. [8] Damping device (11) according to claim 6 or 7, characterized by , that the solid foam is enclosed by at least one gas-impermeable layer (22). [9] Damping device (11) according to any one of the preceding claims, characterized by that the damping fluid is oil. [10] Furniture fitting for a movable part of furniture, characterized by a damping device (11) according to any one of claims 1 to 9. [11] Use of a fluid provided with at least one emulsifier as a damping fluid in a damper (12) of a damping device (11) according to any one of claims 1 to 9 for a movable furniture part. [12] Use of the damping device (11) according to any one of claims 1 to 9 in a furniture fitting on a drawer, door and / or flap.

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