EP2998072B1 - Suspension strut tensioner for exchanging a spring or a shock absorber of a suspension strut of a motor vehicle - Google Patents

Description

The present invention relates to a strut tensioner for replacing a spring or a shock absorber of a strut of a motor vehicle according to the preamble of one of claims 1 or 5.

For damping individual wheels of a motor vehicle, suspension struts are used which comprise a spring preferably made of steel and a piston-cylinder shock absorber that is at least partially guided inside the spring. The spring is firmly connected to the shock absorber, so that the properties of the spring are combined with the properties of the shock absorber to dampen the wheel.

If either the spring or the shock absorber has to be removed due to a defect or due to wear, the spring must be decoupled from the shock absorber. To do this, the spring must be tensioned with a spring tensioner so that there is no longer any force acting on the shock absorber. Only then can the corresponding screws be loosened. An example of such a transportable spring compressor known from the prior art is shown in FIG Fig. 1 pictured. Two forged steel spring holders are attached to the spring tensioner and engage the spring to be tensioned at a distance from one another.

In the latest generation of suspension struts, a return spring is provided on the piston of the shock absorber, which, when unloaded, brings the piston back into the piston further than before. In order to be able to reassemble the strut after replacing the spring or shock absorber, the spring of the new generation of struts has to be tensioned much more than before, i.e. the spring has to be compressed much more in order to bring the piston back into the cylinder to reach. The spring geometry changes so much that the spring tensioner according to Fig. 1 there is a risk of a pen holder slipping off the spring.

To solve this problem is from the DE 20 2006 007 753 U1 a suspension strut tensioner is known which is attached to a workbench and has a substantially vertically oriented actuator on which a support element is provided in the upper area, a clamping device in the middle area and a support plate for holding the suspension strut in the lower area. A number of movable grippers are provided on the upper support element, by means of which the support element can be brought into the position of the piston, the middle clamping device is held laterally adjustable and the lower support plate is adjustable in height.

From the U.S. 4,732,365 a strut tensioner is known which is mounted on a workbench by means of a workbench holder. A strut mount is also mounted on this workbench, in which the strut to be processed can be inserted. The strut mount is held on the workbench so that it can pivot about its X axis. The suspension strut tensioner is held removably with its standpipe in the workbench holder so that the suspension strut tensioner can be easily removed from the workbench when it is needed for other work.

Overall, the one from the DE 20 2006 007 753 U1 well-known spring tensioner and from the U.S. 4,732,365 known strut tensioner due to its many individual parts very expensive to manufacture and very complicated to use.

Proceeding from this, the present invention is based on the object of creating a strut tensioner of the type mentioned at the outset, which can be manufactured inexpensively and is easy to use.

As a technical solution to this problem, according to the invention, a strut tensioner of the type mentioned with the features of Claim 1 or 5 proposed. Advantageous developments of this strut tensioner can be found in the subclaims.

A suspension strut tensioner designed according to this technical teaching has the advantage that the suspension strut tensioner can be manufactured cost-effectively due to a manageable number of individual parts.

In particular, by using the transportable strut tensioner either as a single actuator according to claim 1 or as a supplementary actuator according to claim 5, the suspension strut tensioner is used both in a stationary suspension strut tensioner according to the invention and as a mobile suspension strut tensioner.

As a result, only one strut tensioner is required for the car workshop, which lowers investment costs. Other workshops already have a mobile suspension strut tensioner and only buy the correspondingly cheaper stationary suspension strut tensioner according to the invention.

In a preferred embodiment, the carrier element is designed as an actuator. This has the advantage that the travel of the strut tensioner is increased because the travel ranges of the stationary actuator and the transportable (mobile) strut tensioner add up.

In a preferred development, the adapter holds the transportable spring tensioner pivotably on the carrier element, so that the head plate held on the spring tensioner can be pivoted away in order to create space for removing the helical spring or the shock absorber.

In a particularly preferred embodiment, an adjusting device is provided between the carrier element and the strut mount, or between the actuator and the strut mount, via which the strut can be moved in the direction of the X-axis and / or via which the strut can be moved around the X-axis is pivotable. In particular with asymmetrical helical springs it happens that after separating the piston from the helical spring, either the piston or the helical spring or both leave their original position and are no longer aligned with the opening in the head plate. When assembling the strut, the fitter can move the coil spring into the desired position because it is easily accessible, but the piston located inside the coil spring is difficult to access, especially if it has been pulled into the cylinder by the return spring of the new generation. In this situation, the piston can easily be brought into the desired position with the adjusting device in order to be able to assemble the strut in a simple manner.

It has proven to be advantageous to attach the strut mount to the actuator via a cylinder-piston guide, because this cylinder-piston guide allows axial displacement and requires few components. Another advantage is that this cylinder-piston guide allows swiveling in addition to the axial displacement, so that sufficient adjustment options are realized.

In a preferred development, the adjustment of the strut takes place via a frame attached to the strut mount, which surrounds the actuator and is equipped with an adjusting screw. With this, an adjustment possibility is realized with the simplest structural means, which can be produced very inexpensively and with which a precise adjustment of the spring strut is possible.

If the frame is supplemented with one or two limiting screws that push one another on the workbench holder, the strut can also be pivoted precisely about the X-axis without significantly increasing the manufacturing costs.

Fig. 1

eine perspektivische Ansicht eines aus dem Stand der Technik bekannten transportablen Federspanners;

Fig. 2

eine Frontansicht einer ersten Ausführungsform eines erfindungsgemäßen Federbeinspanners;

Fig. 3

eine Frontansicht des Federbeinspanners gemäß Fig. 2 in explosionsartiger Darstellung;

Fig.3a

eine Detailansicht des Federbeinspanners gemäß Fig. 2 entlang Linie IIIa - IIIa in Fig. 3;

Fig. 4

eine Seitenansicht des Federbeinspanners gemäß Fig. 2 mit einem darin eingesetzen Federbein;

Fig. 5

eine Frontansicht des Federbeinspanners gemäß Fig. 4 mit einem darin eingesetzten Federbein;

Fig. 6

eine Detailvergrößerung des Federbeinspanners gemäß Fig.4, entlang Linie VI in Fig. 4;

Fig. 7

eine Detailvergrößerung des Federbeinspanners gemäß Fig. 4, entlang Linie VII in Fig. 4;

Fig. 8

eine Frontansicht einer zweiten Ausführungsform eines erfindungsgemäßen Federbeinspanners;

Fig. 9

eine Frontansicht des Federbeinspanners gemäß Fig. 8 in explosionsartiger Darstellung;

Fig.9a

eine Detailansicht des Federbeinspanners gemäß Fig. 8 entlang Linie IXa - IXa in Fig. 9;

Fig. 10

eine Seitenansicht des Federbeinspanners gemäß Fig. 8 mit einem darin eingesetzen Federbein;

Fig. 11

eine Frontansicht des Federbeinspanners gemäß Fig. 10 mit einem darin eingesetzten Federbein;

Fig. 12

eine Detailvergrößerung des Federbeinspanners gemäß Fig. 10, entlang Linie XII in Fig. 10;

Fig. 13

eine Detailvergrößerung des Federbeinspanners gemäß Fig. 10, entlang Linie XIII in Fig. 10;

Fig. 14

eine Frontansicht einer dritten Ausführungsform eines erfindungsgemäßen Federbeinspanners in explosionsartiger Darstellung;

Fig. 15

eine Seitenansicht des Federbeinspanners gemäß Fig. 14 mit einem eingesetzten Federbein.

Further advantages of the strut tensioner according to the invention emerge from the accompanying drawings and the embodiments described below. The features mentioned above and below can also be used according to the invention individually or in any combination with one another. The embodiments mentioned are not to be understood as a conclusive list, but rather have an exemplary character. Show it:

Fig. 1

a perspective view of a known from the prior art transportable spring compressor;

Fig. 2

a front view of a first embodiment of a strut tensioner according to the invention;

Fig. 3

a front view of the strut tensioner according to Fig. 2 in an explosion-like representation;

Fig.3a

a detailed view of the strut tensioner according to Fig. 2 along line IIIa - IIIa in Fig. 3 ;

Fig. 4

a side view of the strut tensioner according to Fig. 2 with a strut inserted therein;

Fig. 5

a front view of the strut tensioner according to Fig. 4 with a strut inserted therein;

Fig. 6

an enlarged detail of the strut tensioner according to Fig. 4 , along line VI in Fig. 4 ;

Fig. 7

an enlarged detail of the strut tensioner according to Fig. 4 , along line VII in Fig. 4 ;

Fig. 8

a front view of a second embodiment of a strut tensioner according to the invention;

Fig. 9

a front view of the strut tensioner according to Fig. 8 in an explosion-like representation;

Fig.9a

a detailed view of the strut tensioner according to Fig. 8 along line IXa - IXa in Fig. 9 ;

Fig. 10

a side view of the strut tensioner according to Fig. 8 with a strut inserted therein;

Fig. 11

a front view of the strut tensioner according to Fig. 10 with a strut inserted therein;

Fig. 12

an enlarged detail of the strut tensioner according to Fig. 10 , along line XII in Fig. 10 ;

Fig. 13

an enlarged detail of the strut tensioner according to Fig. 10 , along line XIII in Fig. 10 ;

Fig. 14

a front view of a third embodiment of a strut tensioner according to the invention in an exploded view;

Fig. 15

a side view of the strut tensioner according to Fig. 14 with an inserted strut.

Fig. 1 shows a transportable strut tensioner 1 with a telescopic actuator 2, comprising an outer tube 4 and an inner tube 6 that can be retracted into it. The outer tube 4 and the inner tube 6 are connected to one another via an inner spindle (not shown here) in such a way that when a rotary knob 8 the spindle moves the inner tube 6 relative to the outer tube 4. On the outer tube 4 and also on the inner tube 6, a spring holder receptacle 10 for receiving a spring holder 12 is provided.

These spring holders 12 engage in the interior of a helical spring 14 so that the two spring holders 12 are moved towards one another by actuating the rotary knob 8 and so that the helical spring 14 is tensioned accordingly.

The spring holder receptacle 10 comprises a circumferential shoulder 16, a thread 17 and a threaded sleeve 18, the spring holder 12 being inserted between shoulder 16 and threaded sleeve 18 in the spring holder receptacle 10 before the threaded sleeve 18 is screwed into the thread 17 and thereby clamps the spring holder 12 .

This spring tensioner 1 is transportable and suitable for tensioning the coil spring 14 of a suspension strut, even if the coil spring 14 is still mounted on the vehicle together with the suspension strut.

In the latest generation of struts, a return spring is mounted on the piston of the shock absorber, which brings the piston back into the cylinder of the shock absorber as soon as it is relieved. To dismantle a strut, this means that the helical spring 14 must be compressed further than before so that the piston, which has now been brought back into the cylinder, can be reached for the purpose of mounting in the strut. Such an extreme compression of the coil spring 14 is with the in Fig. 1 illustrated spring tensioner is not always possible, in particular because the spring holder 12 engage in the helical spring 14 and thus only a limited number of spring turns can be used.

In the Figures 1 to 7 a first embodiment of a strut tensioner 100 according to the invention is shown. This suspension strut tensioner 100 has a workbench holder 120 so that the entire suspension strut tensioner 100 can be mounted on a workbench, not shown here. This makes it possible that the strut in one for the fitter comfortable working posture on a workbench to disassemble or assemble.

The suspension strut tensioner 100 further comprises a vertically aligned actuator 122, on which an adjusting device 124 is attached, projecting radially, to which a suspension strut receptacle 126 is connected. The suspension strut receptacle 126 engages around a cylinder 128 of a suspension strut 130 and thus holds the suspension strut 130 securely and in a non-slip manner on the suspension strut tensioner 100.

In the embodiment shown here, the suspension strut receptacle 126 comprises two separate half-shells 132, which are held together via a right and a left retaining screw 134 and in the process clamp the cylinder 128 on the suspension strut tensioner 100.

The upper, free end of the actuator 122 is designed as an adapter receptacle 136 to which a corresponding adapter 138 can be attached. In this adapter 138 a known spring tensioner 1 according to FIG Fig. 1 by means of its spring holder receptacle 10 held on the inner tube 6, in order to achieve an extension of the actuator and, if necessary, an increase in the travel range.

For this purpose, the adapter receptacle 136 is designed as a thread and has a bore 140 on a front side for receiving a socket pin 142. The adapter 138 has an internal thread, not shown here, with which the adapter 138 can be screwed onto the adapter receptacle 136. The adapter 138 is screwed on so far that the socket pin 142 can get into the bore 140 through an opening 144 in the adapter.

The adapter 138 attached to the actuator 122 by means of the internal thread is basically rotatable about its longitudinal axis together with the spring tensioner 1 held in the adapter 138 and is locked by the socket pin 142. This has the advantage that the spring tensioner 1 can be pivoted away, for example by 90 °, if necessary, in order to more easily remove the helical spring 14 from the spring strut 130. For this purpose, the socket pin 142 only needs to be pulled.

The adapter 138 is designed to be open at the top and to the front and has a retaining edge 146 below which a shoulder receptacle 148 is designed. This shoulder receptacle 148 is designed to correspond to the shoulder 16 of the spring holder receptacle 10. The spring tensioner 1 is pushed with its spring holder receptacle 10, in particular with its wide shoulder 16 into the shoulder receptacle 148 and then the threaded sleeve 18 of the spring tensioner 1 is screwed into the thread 17 in order to tension the shoulder 16 against the retaining edge 146 so that the spring tensioner 1 is held firmly and wobbly in the adapter 138.

Either a spring holder 12 known from the prior art or a head plate 152 can then be attached to the spring holder receptacle 10 attached to the outer tube 4 of the spring compressor 1. In the in the Figures 2 to 7 In the first embodiment shown, a head plate 152 is inserted into the spring holder receptacle 16, which acts from above on the spring strut 130 as soon as the head plate 152 is moved against the spring force of the helical spring 14 by actuating either the actuator 2 of the spring tensioner or the actuator 122 of the spring strut tensioner.

The head plate 152 has a central opening 154 for receiving the free end of the spring strut 130. At the same time, a circumferential safety web aligned in the direction of the spring strut 130 is on the head plate 152 156 is provided, against which the free end of the spring strut 130 abuts, should it come out once on the opening 154. This prevents the spring strut 130 from falling out unintentionally.

With the use of the stationary actuator 122 in the strut tensioner according to the invention and with the use of the transportable spring tensioner 1, a very large adjustment path is achieved so that the helical spring 14 of the suspension strut 130 can be compressed sufficiently, even if a return spring, not shown here, pushes the piston 158 catches up with cylinder 128.

In another embodiment, not shown here, a spring holder 12 can also be used instead of the head plate 152. This then engages in the helical spring 14. Although the theoretically possible travel range is reduced in this case, it is still sufficient in many cases.

In the case of a large number of the suspension struts installed in the known vehicles, the helical spring is not designed symmetrically to the axis of the suspension strut but has irregular shapes. If the piston of the shock absorber is decoupled from the helical spring in such an irregular helical spring, it can happen that the helical spring is offset with respect to the piston, so that both are no longer aligned coaxially. When assembling such a suspension strut, there is then the difficulty that when the helical spring is compressed, the free end of the piston no longer hits the opening of the head plate, so that it is difficult to screw the suspension strut together.

In order to facilitate the assembly, the adjusting device 124 is provided between the actuator 122 and the strut mount 126. If you lay fictitiously a coordinate system on the strut tensioner according to the invention, the actuator 122 is designed in the direction of the Y-axis, while the adjusting device 124 acts in the direction of the X-axis.

The adjusting device 124 comprises a hollow cylinder 160 which is attached to the actuator 122 and in which an adjusting piston 162 is guided with an accurate fit. The spring strut receptacle 126 is attached to this adjusting piston 162. In addition, a frame 164 is attached to this strut mount 126, which surrounds the hollow cylinder 160 and the actuator 122 without touching them.

On the other side of the actuator 122 is an adjusting screw 166, which is held near the head end via an adjusting thread in the frame 164, while the free end of the adjusting screw 166 is rotatable and is held axially immovable on the actuator 122. For this purpose, a U-shaped holding web 168 is attached to the actuator 122, which is encompassed by two thrust bearings 170 seated on the adjusting screw 166, the axial bearings 170 being pressed against the holding web 168 by a lock nut 172 located on the adjusting screw 166 in order to move the adjusting screw smoothly rotatable and yet to be kept axially immovable.

The adjusting screw 166 is arranged axially in alignment with the axis of the hollow cylinder 160 or with the axis of the adjusting piston 162.

Because the adjusting screw 166 is held axially immovable but rotatable on the retaining web 168, when the adjusting screw 166 is rotated via the thread located in the frame 164, the frame 164 together with the strut mount 126 and the strut 130 held therein and the adjusting piston 162 in the direction of the X- Axis moved. The adjusting piston 62 is thereby moved into and out of the hollow cylinder 160. It understands that the adjusting piston 162 always remains so far in the hollow cylinder 160 that the spring strut 130 is reliably held on the actuator 122.

The frame 164 is spaced so far from the actuator 122 that a pivoting of the spring strut 130 about the X axis is also possible. The frame 164 pivots together with the adjusting piston 162 and the spring strut 130 about the axis of the hollow cylinder 160, which is also the axis of the adjusting screw 166 or the adjusting piston 162. A limiting screw 174 is provided on each of the right and left edges of the frame 164, which limits the pivoting. The limiting screw 174 hits the workbench holder 120. Conversely, it is of course also possible to pivot the spring strut 130 precisely and in small steps about the X axis by tightening the limiting screw 174.

Both through the movement in the direction of the X-axis and the movement around the X-axis, it is possible to align the piston 158 of the spring strut 130 so that it, while the helical spring 14 is compressed, enters the opening 154 of the Head plate 152 arrives.

The ones in the Figures 8 to 14 The illustrated second embodiment of a strut tensioner according to the invention differs from that in FIG Figures 2 to 7 illustrated first embodiment only in that the actuator (122) is replaced by a support element 222. This support element 222 is a simple tube which cannot be adjusted or lengthened. Everything else remains unchanged. The above for the first embodiment with respect to Figures 2 to 7 said applies to those in the Figs. 8 to 13 shown second embodiment in the same way with the proviso that the actuator (122) has been replaced by the tube-like support element (222).

This second embodiment is thus more cost-effective to manufacture, but has a shorter travel range. However, this shorter travel range is still sufficient for many suspension struts.

The ones in the Figs 14 and 15th The third embodiment shown differs from that in FIGS Figures 2 to 7 The first embodiment shown only in that on the adapter receptacle 136 no adapter (138) for receiving a spring compressor (1), but a spring holder adapter 338 is attached to which the head plate 152 or the spring holder 12 can be attached directly. This spring holder adapter 338 is designed externally analogously to the spring holder receptacle 10 so that the spring holder 12 or the head plate 152 can be fastened to it in a manner known per se. Inside, the spring holder adapter 338 is designed analogously to the adapter 138 so that the spring holder adapter 338, like the adapter 138, can also be attached to the adapter receptacle 136 of the actuator 122. Otherwise, both embodiments are structurally identical, which is why this is the case with the first embodiment according to FIGS Figures 2 to 7 said in an analogous manner for this third embodiment according to the Figs. 14th and 15th applies.

This also reduces the travel of the strut tensioner according to the invention, but this is sufficient in many cases.

Claims (9)

1. A suspension strut compressor for replacing a spring or a shock absorber of a suspension strut of a motor vehicle, comprising a support element (122, 222), a workbench holder (120) for mounting the suspension strut clamp (100) on a workbench,
   wherein a spring holder (12) or a head plate (152) can be attached to the spring compressor (1),
   characterised in that
   a suspension strut retainer (126) is attached to the support element (122, 222),
   in that an adapter (138) for attaching a transportable spring tensioner (1) is provided on the support element (122, 222),
   wherein the adapter (138) is designed to be open at the top and/or towards the front side for receiving the transportable spring tensioner (1).
2. The suspension strut compressor according to claim 1,
   characterized in that
   the support element is designed as an actuator (122).
3. The suspension strut compressor according to one of the preceding claims,
   characterized in that
   the adapter (138) holds the transportable spring compressor (1) axially aligned on the support element (122, 222).
4. The suspension strut compressor according to one of the preceding claims,
   characterized in that
   the adapter (138) holds the transportable spring compressor (1) on the actuator (122) so as to be pivotable about the axis of the support element (122, 222).
5. A suspension strut compressor for exchanging a spring or a shock absorber of a suspension strut of a motor vehicle, comprising an actuator (122), a workbench holder (120) for mounting the suspension strut compressor (100) on a workbench, wherein a spring holder (12) or a head plate (151) can be mounted on the actuator (122),
   characterized in that
   a suspension strut retainer (126) is mounted on the actuator (122) and that an adjusting device (124) is provided between the suspension strut retainer (126) and the actuator (122), by means of which the suspension strut (130) can be moved in the direction of an X-axis and by means of which the suspension strut (130) can be pivoted about the X-axis, and in that the adjusting device (124) has an adjusting piston (162) which is aligned in the direction of the X-axis and which is guided in a hollow cylinder (160) attached to the actuator (122) and also aligned in the direction of the X-axis.
6. The suspension strut compressor according to claim 5,
   characterized in that
   the adjusting device (124) has a frame (164) which surrounds the actuator (122), is connected to the suspension strut retainer (126) and has an adjusting screw (166) which acts on the actuator (122) preferably in the direction of the X-axis.
7. The suspension strut compressor according to claim 6,
   characterized in that
   the adjusting screw (166) is rotatably held in an adjusting thread integrated in the frame (164) and in a holding web (168) attached to the actuator (122).
8. The suspension strut compressor according to one of the preceding claims
   characterized in that
   a central opening (154) is made in the head plate (152) and in particular that the head plate (151) has a lateral safety web (156) to prevent the suspension strut (1) from breaking away.
9. The suspension strut compressor according to one of the preceding claims,
   characterized in that
   the suspension strut retainer (126) surrounds and holds the suspension strut (1) in the region of the cylinder (128) of the shock absorber.

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