DE7535393U - Gas spring with end cushioning - Google Patents

Description

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STABILUS GMBH, Koblenz-Neuendorf utility model registration

Pan spring with end cushioning

Get innovation relates to a gas spring with end damping, b, _c ctohend of a cylinder, which is precipitated with gas under pressure, and optionally a small amount of liquid containing, with a firmly connected with a piston rod KOLBON is arranged in the cylinder interior, which the Cylinder interior is divided into öwei Teilräuine and these subspaces are connected by a throttle device, while the guide and seal for the piston rod is present at the piston rod outlet end in the cylinder and the piston rod at the piston rod has a blind hole designed as a blind hole in which to connect with a radial bore opens into the annular subspace.

when installing gas springs as a counterbalance for tailgates, bonnets and others around a horizontally arranged axis of rotation hinged doors often there is a desire that the gas spring when opening the flap swings up with this to to ensure unhindered access to the open space. By swiveling the gas spring, the division is closed the flap or hood the piston rod downwards from cera cylinder, while in the open position the piston rod upwards ^ protrudes from the cylinder.

Di *? known gas springs have a piston rod protruding downwards the effect d =? r end damping by the piston just before End of stroke in the area of the piston rod guide and piston rod seal accumulated oil dips. When installing such gas springs for tailgates of motor vehicles is disadvantageous that when pivoting with the Keckklappe of the motor vehicle and the after

7535393 iiea78

There is no end cushioning at the top of the piston rod emerging. Due to the lack of end damping is when the flap is opened there is a hard end stop, which the Anlenkpumfefe to The body and tailgate as well as the hinges are very heavily used, because the extension speed of the piston rod is suddenly decelerated to zero when the flap is fully open.

Dip task of the present innovation is to create a gas spring that also when the piston rod is pivoted upwards has perfectly functioning end muffler and this end muffler rustic is achieved with simple means.

According to the innovation, this object is achieved in that a sleeve with its bore and the outer surface of the piston rod fastened in the cylinder in the area of the piston rod guide forms an annular space in which the radial bore is immersed from a predetermined extension path of the piston rod. By immersion the radial bore in the annular space, a change in the damping for the gas spring is achieved in a simple manner, wherein it is just a question of how strong the annulus is the attenuation is to be changed. It is also possible through this training, either with liquid or with gas Bring about final attenuation.

In order to be able to fully utilize the path for the end damping, it is advantageous according to a feature of the innovation if the axial extent of the annular space in the sleeve corresponds to the distance between the radial bore and the end face of the piston facing the subspace.

The definition of the path of the end damping can be done in a simple manner in that, as the innovation shows, the distance from the piston face to the radial bore forms the specified damping path for the end damping.

A gradual increase in end attenuation is like a feature

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the innovation shows that it is easy to achieve that the Sleeve has a conical central bore. This results in a very gentle braking when opening the flap or dpr hood scored. It can also be an advantage in the case of installation be if the damping is formed by an annular space, which is according to new several holes with different diameters having. In addition, the combination of the conical central bore with several different in diameter Boring easily possible.

Further training opportunities and beneficial effects result from the B description of the structure and the mode of operation of the embodiments shown in the following as an example the innovation. It shows:

Fig. 1 shows the arrangement of a gas spring on a tailgate pivotable about a horizontal axis of rotation in a schematic
Depiction;

Fig. 2 is a longitudinal section through the gas spring, with between

Piston rod and sleeve a cylindrical annular space is formed;

3 shows a detail of an embodiment with a conically formed Central bore of the sleeve and

Fig. M shows a detail of an embodiment, the sleeve several has different bores in diameter.

In the schematic representation of FIG. 1, the gas spring is
3 with a joint part fastened on the piston rod 7
pivotally connected to a tailgate 1. Also pivotally, the other end of the gas spring 3, it is ordnets which forms the pivot point ¹ I on a body-fixed part.
When opening, the flap 1 pivots about the axis of rotation 6. In the
oie flap 1 is in the closed position against stop 2 of the

Body on, the pivot point 5 connected to the piston rod 7 being below the pivot point 4.

If the flap 1 is opened, the gas spring presses the flap 1 as a result of the gas pressure acting on the piston rod upwards, v / obei is the pivot point 5 on the dash-dotted line drawn arc moves. The open position of the Cliff 1 is shown in dashed lines in FIG. 1, whereby erriehtIich is that dr-r in the closed position is below dps Schwenkpunktos 4 arranged pivot point 5 in the open Position above the pivot point 4 is. By swiveling along the gas spring 3 with the flap 1 is an unimpeded loading and unloading of the trunk in the open position of the Tailgate allows.

Fig. 2 shows the gas spring 3 approximately in the position in which the The flap is closed, i.e. with the piston rod 7 retracted. The gas spring consists of the cylinder 8 on its inner surface the piston 9 connected to the piston rod 7 slides. This piston 9 has the actual piston body and one between the disc 11 and the piston body axially movable piston ring 10. In the piston rod 7 is at the piston-side end the axial bore 12 is arranged, into which the radial bore 13 opens. These two bores 12 and 13 form the connecting channel between the sub-space 14 and the annular one Subspace 15, the radial bore 13 being designed as a throttle bore. At the end of the piston rod outlet is im Cylinder 8 fastened the sleeve 16, the bore of which forms the annular space 17 with the outer surface of the piston rod 7. Except the one below Pressurized gas filling in the subspaces l4 and 15 is a relatively small amount of oil contained in the gas spring, which is in the closed position of the flap in the area of the sleeve 16 and thus also in the area of the seal and guide for the piston rod 7, which ensures a perfect seal and low wear of the piston rod seal due to wetting the piston rod 7 is achieved.

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When the tailgate is opened, the gas spring 3 swings about its pivot points, the position of the gas spring changing as the piston rod extends. Due to the friction on the inner wall of the cylinder, the piston ring 10 rests against the piston body of the piston 9 and seals the piston against the inner wall of the cylinder. Thus, the damping of the extension movement of the piston rod 7 is brought about only by the radial bore 13. During this extension movement of the piston rod 7, the gas flows out of the annular subchamber 15 via the bores 13 and 12 into the subchamber 1Ί. Due to the pivoting of the gas spring 3 with the flap, the oil filling located in the area of the sleeve 16 flows in the direction of the Kcl-.on 9 and collects there. The amount of oil filled into the gas spring 3 is decisive for the point at which the oil is displaced ^{into the partial space l 1 »through the radial bore 13.} If the bore 13 now reaches the area of the annular space 17 formed by the sleeve 16 when the piston rod 7 is extended, an additional throttling is effective. As soon as the radial bore 13 plunges into the annular space 17, a further throttle cross-section is effective, which becomes longer and longer when the piston rod extends, i.e. as the radial bore 13 penetrates further into the sleeve 16, thus increasing the damping for the extension movement of the piston rod 7 causes. In addition to the cross-section of the radial bore 13, the wall thickness of the annular space 17, ie the gap between the sleeve Io and the piston rod 7, forms a measure of the damping effect in the end area The distance between the radial bore 13 and the perforated disk 11 can easily be adapted to a given path for the end damping. The sua'itzliche D. inoculation in the end areas produces a slow piston movement, so that a metallic contact the r.olbenc will rent out.

Bf * when the flap is closed, it is counter to the spring force the gas spring 3 is pressed downwards, with the piston ring 10 on the perforated disc as a result of the friction

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11 comes to the plant and one to the holes 12 and 13 additional Passage cross-section between the space 14 and the space 15 is formed. Thus, the gas flows out of the first Subspace 14 through these opened cross-sections into the annular subspace 15, namely until the pivoting of the gas spring 3, the oil ″ located in the subspace 14 around the piston 9 flows. After the gas spring 3 has fallen below the horizontal installation position, the oil runs over the bore 12, the radial bore 13 and through the cross-section released by the piston ring 10 from the subchamber 14 back into the annular subchamber 15, so that the entire amount of oil is in the area of the sleeve 16 again when the flap is closed.

The Aus ? 3 differs essentially from that according to FIG. 2 in that the sleeve l6 has a conical central bore l8. If the radial bore I3 of the piston rod 7 now plunges into this inner space 17 formed by the radial bore 18, a smaller gap between the radial bore 13 and the sleeve 16 is constantly active when the piston rod 7 is extended, resulting in a greater increase in the damping effect is achieved. The situation is similar in the embodiment shown in FIG. 4, the sleeve 16 having bores 19, 20 and 21 different in diameter.

Since the cross section of the annular space 17 is slightly the required If the damping effect can be adapted w-rd-n, it is easily possible that instead of <i ^ r Vf rbeachr ied final damping by means of pure oil Gas damping al .. Undamping is provided.

7. 10. 7 ^
TIP-I Be / Bb-

7535393 03/11/76

Claims (4)

1. Gas spring with end cushioning, consisting of a cylinder, which is filled with pressurized gas and optionally contains a small amount of liquid, in the cylinder interior a piston is fixedly connected to a piston rod and divides the cylinder interior into two sub-spaces divided and these subspaces are connected by a throttle device, while on the piston rod outlet side At the end of the cylinder there is a guide and seal for the piston rod and the piston rod on the piston side End has an axial bore designed as a blind bore, in which for connection to the annular Partial space opens into a radial bore, characterized in that one in the area of the piston rod guide in the cylinder (8) attached sleeve (16) with its bore and the outer surface of the "piston rod (7) forms an annular space (17) in which From a predetermined extension path of the piston rod (7), the radial bore (13) is immersed. 2. Gas spring according to claim I _9, characterized in that the axial extent of the annular space (17) in the sleeve (16) corresponds to the distance between the radial bore (13) and the end face of the piston (end face of the disk 11) facing the subspace (15) . 3. Gas spring according to claims 1 and 2, characterized in that the distance between the piston face (disk 11) and the radial bore (IJ) forms the specified damping path for the end damping. 4. Gas spring according to claims 1-3, characterized in that that the sleeve (16) has a conical central bore (18). 7535393 03/11/76 5- gas spring according to claims 1-3, characterized in that that the sleeve (16) has several bores (19, 20, 21) of different diameter. 7-10.75
TIP-I Be / Bb- 7535393 11.O3.76