EP2163349A2 - Device for tensioning a shock absorber - Google Patents

Abstract

The device (21) has a gripping element (20) connected with a spring coil (22) of a helical spring (23), which is inserted into a spring damper strut. A piston rod (28) of the spring damper strut is provided with a retainer (27). A holder (1) is provided in a region of the gripping element, and is moveable from a neutral position into an effective position, in which the holder is connected with the radially projecting part. The holder is not connected with the radially projecting part in the neutral position.

Description

The invention relates to a device for tensioning a spring damper strut having at least one gripper element, which engages during tensioning with a spring coil of a spring in the strut between an upper and a lower spring plate under bias coil spring engaged and with a coupling element, which with one of the first spring coil axially spaced part, in particular with the lower spring plate of the spring damper strut is engaged, wherein for tensioning the coil spring, the axial distance between the gripper element and the coupling element is variable and, wherein the spring damper strut has a piston rod, which is provided with a radially projecting part.

Spring damper legs are known from the prior art, in particular from the automotive industry, for a long time. Such a spring damper leg has a coil spring which is accommodated under tension between an "upper" and a "lower" spring plate of the spring damper leg. The lower spring plate is fixed to a so-called damper tube, which is in operation is mounted on a axle component to be mitigated. This damper tube serves to receive a so-called. Shock absorber, which in turn is provided with a piston rod which protrudes vertically upwards from the damper tube. In the upper end of this piston rod, a mounting thread is provided, via which the piston rod with the upper spring plate is fixed coupled. The maximum distance between the lower spring plate and the upper spring plate is thus determined in the assembled state by the length of the protruding from the damper rod piston rod. Furthermore, constructions of spring damper legs are known in which this piston rod below the upper spring plate has a radially projecting part, which is formed plate-like in the rule. Also, the piston rod itself may have a radially expanded shoulder, which is also arranged at an axial distance from the upper spring plate. In general, the piston rod in modern axle construction in the region of the upper spring plate, a radially projecting part, in particular in the form of a plate, which serves to attach a protective cover for the piston rod.

In newer vehicle designs and in particular in so-called sports suspensions, what are known as gas shock absorbers are used as shock absorbers, which are characterized in that the piston rod is acted upon by an axial force pressing against the upper spring plate. This means that the piston rod always remains in its "extended" state due to this axial force.

To remove spring damper legs from a motor vehicle, known so-called. Federspanner be used. For this purpose, the spring used between the spring plates under bias coil spring is tensioned with the spring tensioner, so shortened in block tensioned coil spring, the axial distance of the two spring plate. In conventional spring damper legs so that shortens the entire length of the spring damper strut, so that this are taken out after the tensioning of the coil spring from the vehicle.

Different spring tensioners are used for tensioning coil springs. For that be exemplary on the DE 196 31 524 C1 or even the DE 93 14 698 U1 referenced, in which two different basic designs of spring tensioners are described.

At the subject of DE 196 31 524 C1 it is a so-called Konsolfederspanner, which has an externally to be arranged outside of the exciting coil spring tensioning device, which in turn is provided for tensioning the coil spring with two gripper elements. When attaching this spring tensioner, the first (upper) gripper element is brought into engagement with a spring coil in the vicinity of the upper spring plate, this gripper element is designed approximately claw-shaped or fork-shaped. The lower gripper element may be identical and be suspended in a lower spring coil. It is also known to design the lower gripper element as a kind of coupling element, so that this can be brought into engagement, for example, with the lower spring plate. Is the lower gripper element designed as a coupling element, the coil spring is clamped during the clamping operation against the lower spring plate. In conventional spring damper legs, which have a conventional shock absorber and no gas pressure shock absorber, thus the total length of the spring damper strut can be shortened by this clamping operation, so that this spring strut can be easily removed from a motor vehicle.

Similarly, the spring compressor is after the DE 93 14 698 U1 can be used, this having a different basic structure. Here, two tension spindles are used for clamping the coil spring, which have hook-shaped gripper elements in its upper end region, which are attached to the coil spring diametrically opposite in a arranged in the region of the upper spring plate spring coil. At the subject of DE 93 14 698 U1 are also the lower gripper elements or coupling elements hook-shaped and are also suspended in a spring coil. Even with such spring tensioners with two tension spindles, it is known to couple the lower ends of the tension spindles via pull nut and a kind of clamping plate, for example, with the lower spring plate. By uniform tightening the tension nuts, we thus clamped here, the coil spring against the lower spring plate, so that in conventional spring damper legs (without gas spring) also shorten the overall length of the spring damper leg.

However, if gas pressure shock absorbers are provided as shock absorbers, then this shortening of the entire spring shock absorber leg or the reduction of the distance of the two spring plates takes place does not take place because the upper spring plate is held by the piston rod in its maximum distance from the lower spring plate. Thus, it is difficult or impossible to remove such a spring strut from a motor vehicle with the known spring tensioners.

Accordingly, the invention has the object, an apparatus for tensioning a spring damper strut with gas spring in such a way that even such a spring damper strut for removal from a motor vehicle can be shortened.

The object is achieved according to the invention together with the features of the preamble of claim 1, characterized in that in the region of the gripper element, a holding element is provided, which consists of a neutral, not with the part of the piston rod engaged position in an effective, with the part of the piston rod engageable position is adjustable.

The inventive design, a device for tensioning a spring damper leg is provided, with which a spring damper strut is shortened as a whole, which has a gas spring as a shock absorber.

For this purpose, it is provided that an additional retaining element is provided in the region of the gripper element. This additional holding element is adjustable from a neutral, not with the radially projecting part of the piston rod engaged position in an operative, with the radially projecting part of the piston rod engaged position. That is, such a device in conventional manner, as is generally known from the prior art for spring compressor, on a coil spring or on a spring damper leg is attachable. After attaching, in particular, the upper, in the region of the upper spring plate attached gripper element, the holding element can now be adjusted "into the spring" and thus be brought into engagement with the radially projecting part of the piston rod.

During the subsequent tightening of the coil spring against the lower spring plate, the distance of the gripper element is shortened to the lower spring plate, so that the coil spring is tensioned. Since the piston rod is engaged via the radially projecting part with the additional holding element, the piston rod is also pressed into the shock absorber at the same time. This ensures that the spring damper overall shortened during the clamping process and can be taken out of a motor vehicle readily at the end of the clamping process.

Further advantageous embodiments of the invention can be taken from the further subclaims.

Thus, it can be provided according to claim 2, that the holding element for coupling to the part of the piston rod has a fork-shaped coupling portion. By means of this fork-shaped coupling section, the retaining element can be brought into engagement in a simple manner with the radially projecting part of the piston rod. For this purpose, this fork-shaped coupling portion is only above this radially projecting part radially from the outside on the Piston rod "postponed", so there is a safe intervention.

Furthermore, it can be provided according to claim 3, that the holding element is pivotally mounted on the gripper element and at least in its engaged position with the part of the piston rod can be fixed. This configuration ensures that the retaining element can not slip off the radially projecting part of the piston rod. Due to the pivotable mounting on the gripper element further an extremely simple operation is achieved.

Alternatively to the embodiment according to claim 3, the holding element may also be displaceably mounted on the gripper element and likewise be fixable to the part of the piston rod at least in its engagement position. This also ensures extremely easy operation.

For holding the retaining element on the gripper element can further be provided in a simple manner according to claim 5, a bearing screw. This bearing screw can be solved for example for the adjustment and then tightened again, so that in this way also a fixation of the holding element is achieved at least in the engaged position.

In addition, according to the claims 6 and 7, the fixation can also be done in other ways.

Thus, it can be provided according to claim 6 that a locking element is provided for fixing the engagement position. In such a locking element may be, for example to act a spring-loaded detent ball, which is arranged either in the holding element itself or in the gripper element and engages corresponding detent in a recess or bore of the corresponding other component in the engaged position.

According to claim 7, a clamping screw may be provided for fixing the engagement position, which is tightened in a simple manner after reaching the engagement position of the holding element on the gripper element. This also ensures a fixation of the engaged position sure.

Fig. 1

eine perspektivische Explosionsdarstellung einer ersten Ausführungsvariante eines Halteelementes zusammen mit einer Lagerbuchse sowie einer Montgeschraube;

Fig. 2

eine Draufsicht auf den oberen Teil eines Ausfüh-rungsbeispiels einer Vorrichtung zum Spannen eines Federdämpferbeines mit zwei Zugspindeln und zwei Greiferelementen, bei welchem das Halteelement aus Fig. 1 an einem der Greiferelemente angeordnet ist;

Fig. 3

einen Vertikalschnitt durch den oberen Teil der Vorrichtung aus Fig. 2 in ihrem an einer Schraubenfeder angesetzten Zustand;

Fig. 4

eine zweite Ausführungsvariante eines Halteelementes;

Fig. 5

eine dritte Ausführungsvariante eines Halteelementes.

Reference to the drawings, the invention will be explained in more detail with reference to some embodiments, wherein the configuration of the retaining element is not limited to the specific embodiments. It shows:

Fig. 1

an exploded perspective view of a first embodiment of a holding element together with a bearing bush and a Montgeschraube;

Fig. 2

a plan view of the upper part of an embodiment of a device for tensioning a Federdämpferbeines with two tensioning spindles and two gripper elements, wherein the holding element of Fig. 1 is arranged on one of the gripper elements;

Fig. 3

a vertical section through the upper part of the device Fig. 2 in its attached to a coil spring state;

Fig. 4

a second embodiment of a holding element;

Fig. 5

a third embodiment of a holding element.

Fig. 1 shows a perspective view of a first embodiment of a retaining element 1 together with a bearing bush 2 and a bearing screw 3. The bearing screw 3 is for mounting the retaining element 1 through a corresponding through hole 4 of the bearing bush 2 can be inserted and inserted into a corresponding internal thread of a gripper element or a Pulling spindle are screwed. For rotatable mounting on the bearing bush 2, this forms on the underside a cylindrical bearing section 5 with which the bearing bush 2 can be inserted into a corresponding bearing bore 6 of the retaining element 1 with little play.

The holding element 1 is plate-shaped in the present embodiment and may accordingly consist of a sheet metal component having a thickness between 3 and 5 millimeters. In its opposite end of the bearing bore 6, the holding element forms a fork-shaped coupling portion 7 with two fork legs 8 and 9. Here, the fork leg 9 is an integral part of a connecting portion 10, which in its fork legs 8 and 9 opposite end of a "back" or after outside projecting actuating portion 11 forms. In the region of this operating portion 11, the holding element 1 has a further through-bore 12, which in particular for determining an engagement position, for example releasably engageable with a spring-loaded detent ball. It is easily conceivable that the retaining element 1 can be pivoted about the longitudinal center axis 13 of the bearing bush 2 or the bearing screw 3 in the direction of the double arrow 14 via the actuating portion 11.

Fig. 2 shows the holding element 1 in a state mounted on a gripper element 20 in plan view. This gripper element 20 is part of a device 21 for clamping a spring damper leg. In the present embodiment of this device 21, the gripper element 20, as in particular from Fig. 3 can be seen, hook-shaped and is connected to a spring coil 22 of a coil spring 23 into engagement. In the present embodiment of the device 21, this has a second gripper element 24, which is also hook-shaped and with the same spring coil 22 of the coil spring 23 is engaged, as in particular Fig. 3 is apparent.

The holding element 1 is placed on the top side on the holding element 1 and secured by means of the bearing screw 3 and the bearing bush 2. It is off Fig. 3 recognizable that the gripper element 20 is mounted on a pulling spindle 25, which has a corresponding internal thread 26 for mounting the bearing screw 3. As an alternative to this embodiment with respect to the pulling spindle 25, it may also be provided that the gripper element 20 is closed on the upper side and the internal thread 26 is thus arranged directly in the gripper element 20.

In the Fig. 2 and 3 the holding element 1 is shown in an engaged position, in which the holding element. 1 with its fork-shaped coupling element 7 with a kind of plate 27 is engaged. This plate 27 is axially fixed to a piston rod 28 of a particular in Fig. 3 partially shown spring damper leg 29 arranged. Such a plate is usually used to attach a protective cover, which covers the piston rod 28 in use and thus protects against external influences.

Furthermore, from the Fig. 2 and 3 It can be seen that the second gripper element 24 is also arranged fixedly in the upper end region of a second traction spindle 30 in the region of the upper spring plate 60. For fixed mounting of the upper spring plate, a mounting thread 61 is provided in the end region of the piston rod 28 of the spring damper leg 29, to which a corresponding mounting nut 62 is screwed.

The lower end regions of the two draw screws 25 and 30 can, for example, communicate with a holding plate 64 via corresponding draw nuts 65 and 66. This holding plate 64 is in the clamping process, for example, with the lower spring plate 63 of the spring damper leg 29 into engagement. The lower spring plate 63 is welded in a known manner with the damper tube 32 of the spring damper leg 29 fixed.

When uniformly tightening the tension nuts 65 and 66 thus the coil spring 23 is tensioned against the lower spring plate 63 of the spring damper strut 29 in the direction of the arrow 31. This shortens the entire spring shock absorber leg 29 so that it can be easily removed from a motor vehicle. Due to the intervention of the Holding element 1 with the plate 27 at the same time the piston rod in the direction of the arrow 31 is pressed into the damper tube 32 of the spring damper leg 29, so that a total shortening of the spring damper leg 29 is securely effected during the clamping operation.

As in particular from Fig. 2 can be seen, the holding element 1 from the engagement position shown in solid lines in a neutral, disengaged position can be brought, which in Fig. 2 is shown in phantom lines 33. As a result, the attachment of the device 21 on the Federdämpferbeins 29 and on the coil spring 23 is simplified.

To fix the engagement position, a spring-loaded detent ball may be provided in the gripper element 20 in the region of the through hole 12, so that this engagement position is held securely but releasably.

Also, the through hole 12 may be configured as a threaded bore, in which a, not shown in the drawing, clamping screw is used, so that the holding element 1 against the gripper member 20 can be clamped and thus fixed.

In the drawing figures 4 and 5, two further embodiments of retaining elements 40 and 50 are shown by way of example. These holding elements 40 and 50 have in the illustrated embodiments in each case a holding web 43 or 53 with a longitudinal slot 41 and 51, respectively, and can accordingly be fixed rectilinearly adjustable by means of the bearing bush 2 or the bearing screw 3 on the gripper element 20. In this case, both holding elements 40 form and 50 each have a fork-shaped coupling element 42 and 52, with which the holding elements 40 and 50 by corresponding displacement in the direction of the double arrow 35, for example, with the plate 27 of the piston rod 28 from Fig. 3 can be engaged and disengaged again.

To fix the retaining element 40, the bearing bush 2 can be provided together with the bearing screw 3. By simply loosening the bearing screw 3 off Fig. 3 Thus, a displacement of the retaining element 40 in the direction of the double arrow 35 is made possible. On the other hand, this can be fixed by the bearing screw 3 in the engaged position with a corresponding configuration of the bearing bush 2 fixed on the gripper element 20.

Alternatively, the provided with the longitudinal slot 51 bearing web 53 of the retaining element 50 may also be provided with further holes 54 and 55, which may serve for example for detent fixing both the engaged position and the disengaged position.

It can be seen that the holding elements 1, 40 and 50 can certainly be designed differently. In this case, even further embodiments of such a holding element are conceivable, which is ultimately dependent on the conditions of use and the design of a spring tensioner or a device for tensioning a spring shock absorber leg.

Thus, a gripper element can also be configured, for example, in the manner as in the Konsolfederspanner from the DE 196 31 524 C1 is known. There, such a gripper element is exemplified as a clamping claw.

Claims (7)

Device (21) for tensioning a spring damper leg (29) with at least one gripper element (20), which during tensioning with a spring coil (22) in the spring damper leg (29) between an upper and a lower spring plate (60 and 63) inserted under bias coil spring (23) is engaged and with a coupling element (64), which with a first spring coil axially spaced part, in particular with the lower spring plate (63) of the spring damper leg (29) is engaged, wherein for tensioning the coil spring (23) the axial distance between the gripper element (20) and the coupling element (64) is variable and, wherein the spring damper leg (29) has a piston rod (28) which is provided with a radially projecting part (plate 27),
characterized,
that in the region of the gripper element (20) a holding element (1, 40, 50) is provided, which from a neutral, not with the part of the piston rod (28) in an engaged position (phantom lines 33) in an effective, with the part (plate 27) of the piston rod (28) engageable position is adjustable. Apparatus according to claim 1, characterized in that the holding element (1, 40, 50) for coupling with the part (plate 27) of the piston rod (28) has a fork-shaped coupling portion (7, 42, 52). Apparatus according to claim 1 or 2, characterized in that the holding element (1) on the gripper element (20) is pivotally mounted and at least in its engaged position with the part (plate 27) of the piston rod (28) is fixable. Apparatus according to claim 1 or 2, characterized in that the holding element (40, 50) on the gripper element (20) is displaceably mounted and at least in its engaged position with the part (plate 27) of the piston rod (28) is fixable. Apparatus according to claim 3 or 4, characterized in that the holding element (1) via a bearing screw (3) on the gripper element (20) is adjustably mounted. Apparatus according to claim 3, 4 or 5, characterized in that for fixing at least the engagement position, a latching element is provided. Apparatus according to claim 3, 4 or 5, characterized in that for fixing the engagement position, a clamping screw is provided.

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