EP2882967B1 - Cylinder-piston unit - Google Patents

Description

The invention relates to a cylinder-piston unit whose piston is connected to a protruding on an end face of the cylinder piston rod, according to the preamble of claim 1.

There is a need in the art for precision-acting drive units whose movements are reliably controllable and precisely defined. In particular, in the exact alignment of tools that are used alternately in two different positions, e.g. in a lower tool which is used on a bending machine both for folding and for pressing and is adjustable in the direction of the so-called I-axis, such drive units are used. These consist of a cylinder-piston unit, whose protruding at one end face of the cylinder piston rod drives the tool. In the context of such cylinder-piston units, there is so far no solution to limit the stroke of the piston rod in a reliable, space-saving and cost-effective manner.

The JPS58207508A discloses a cylinder-piston unit with a protruding at both ends of the cylinder piston rod. While at one end of the piston days (in the figures on the right hand side), the coupling of a relative to moving part can be done, located at the opposite end of the cylinder (left hand), a stroke limitation. This includes two Einstellblöcke and a control block which is fixed to the piston rod and moves with it. The stroke of the piston rod is limited in both directions by the setting blocks, which each form a stop for the control block.

The JPS61116111A discloses a cylinder-piston unit with a stroke limitation. At the protruding from the cylinder end of the piston rod is a radially outwardly projecting pin, which forms a stop piece. A cylindrical attachment has on its side facing the pin, distributed along its circumference, different deep incisions. The incisions together with the pin different stop pairings.

The non-generic EP0346504A1 discloses a rodless piston and cylinder assembly with a stroke limiting device. The stroke limiter comprises a drum mounted rotatably next to the cylinder, from which limit stops of different lengths protrude parallel to the cylinder longitudinal axis along its circumference. A movable along the cylinder drive member which is coupled via magnetic arrangements with the piston contactless, forms a stop member, which cooperates with the respectively brought into position limit stop of the drum. The in the EP0346504A1 disclosed stroke limitation is not applicable to cylinders with piston rods. A disadvantage of this arrangement is that the drive member is loaded asymmetrically during the attack. In addition, the movement of the drive member can be limited with the device for limiting the stroke in one direction only.

The FR988036A discloses a lathe with a feed shaft with an adjustable stop. A rotatable about the shaft axis rotating part encloses the shaft and defined depending on the rotational position of a certain limit stop, with which cooperates a tailed to the movable part of the feed shaft stop member. This document is far from the subject invention, since it does not relate to a cylinder-piston unit. As with the EP0346504A1 is also possible here is a limitation of the moving part only in one direction.

The US76732A discloses a hydraulic press, in particular for pressing tobacco with a cylinder and a ring arranged above the cylinder and having graduations on its upper side, which is rotatable with respect to the cylinder and acts as a holding device for the pressing head sitting on the piston rod. The pressing head is connected to the bottom of the pressing frame via vertically extending rods. The holding device allows the holding of the pressing frame in different height positions.

The US3177980A discloses a hydraulic locking device for controlling the relative movement of two parts. An extending beyond the cylinder stop sleeve has in its wall axially extending slots, which have gradations at one of its ends. A pin connected to the piston rod and diametrically oriented pin engages in this slot, whereby its way through the stepped end of the slot is limited. The Sleeve is rotatable, whereby the desired gradation can be selected as stroke limitation.

The DE1964126A1 discloses a locking device for controlling the relative movement between two parts with a hydraulic cylinder connected to one of the two parts. A stop means consists of a first stop, which is drivingly connected to the cylinder, and a second stop, which is drivingly connected to the piston rod. Is on the tubular piston rod. First and second stops cooperate to limit the range of the piston stroke. The stop connected to the piston rod consists of an axially adjacent to the cylinder stop sleeve in which a plurality of gradations are formed in the circumferential direction and which is rotatable about the cylinder axis. With the gradations act radially extending stop fingers of the stop connected to the cylinder.

The FR1596551A discloses a stroke limiter for a cylinder with rods along which stops are linearly adjustable. These rods are guided on a radial extension on the cylinder head and connected to the piston rod via a frame.

The object of the invention is to provide a cylinder-piston unit with which the movement of the piston rod can be reliably and adjustably defined. Preferably, the path of the piston rod should be limited in both directions and variably adjustable. The solution should be space-saving and cost-effective. In particular, the cylinder-piston unit should have a compact construction and be installed in common machine tools without complex adaptations.

This object is achieved with a cylinder-piston unit of the type mentioned above in that the counter-stop part in two areas which are axially spaced from each other with respect to the cylinder axis, respectively forms different limit stops, so that the path of the piston rod in both directions to different degrees is limited. The two axially spaced-apart regions of the counter-abutment part may be, for example, its end faces or laterally projecting sections of the counter-abutment part or facing sections or surfaces.

Such a solution not only allows a reliable and defined adjustable stroke limitation, but also a space-saving, compact design. The latter allows the use of inventive cylinder-piston units in common (tool) machines without complex adaptations. The travel limit for the displacement of tools is thus already integrated into the drive and requires no additional measures, whereby the cost of upgrading a machine with a variable path limitation are kept low.

The second portion may extend outwardly along the cylinder both adjacent thereto and spaced therefrom.

The limit stops associated with the different pairs of stops have different heights or dimensions in the axial direction and therefore limit the axial travel to different degrees. Preferably, the limit stops are integrally formed in the counter-stop piece. At least those limit stops that limit the travel of the stop member in an axial direction are preferably formed integrally with the counter stop member, respectively.

Preferably, the counter-stop member is rotatable relative to the cylinder and / or forms different limit stops, which are each assigned to the different pairs of stops. The axially fixed and thus clearly defined in its axial position counter stop allows the realization of exactly reproducible limit stops and can also be designed as a compact component.

Preferably, the counter-stop part forms on both of its end faces, which are axially spaced from each other with respect to the cylinder longitudinal axis, in each case different limit stops, so that the travel of the piston rod can be limited to different degrees in both directions. This results not only in a direction of the piston rod differently adjustable stop pairings, but also in the opposite direction. This increases the flexibility and possible applications of a cylinder-piston unit.

Preferably, the counter-abutment part is formed from two mutually rotatable sections, wherein one of the two end faces of the counter-abutment part is formed on one of the two sections and the other end face of the counter-abutment part is formed on the other section. As a result, with respect to both directions of movement of the piston rod, any desired combinations of stop pairings can be set and the end stops can be adjusted as required both for the extension and the retraction of the piston rod.

In a preferred development of the invention, the counter-abutment part is formed from two mutually rotatable sections, wherein the one area of the counter-abutment part forming different limit stops is formed on one of the two sections and the other area of the counter-abutment part which forms different limit stops on the other section is formed.

With regard to the last two embodiments and as already mentioned, the two regions which are axially spaced apart from one another with respect to the cylinder longitudinal axis and on which different limit stops are respectively formed, preferably the two end faces of the counterpart stop part.

Preferably, the second portion of the stop member is formed by at least one elongate arm which extends substantially parallel to the longitudinal axis of the cylinder. Such a running arm takes up little space, whereby the cylinder-piston unit can be designed to save space.

Preferably, the second portion of the stop member is formed by at least two substantially mutually parallel arms extending along opposite sides of the cylinder. This allows a symmetrical loading of the stop member and the counter-stop member during the stop, whereby wear or jamming of the moving parts is prevented.

Preferably, the second portion of the stop member has two with respect to the cylinder longitudinal axis axially spaced apart, cooperating with the counter-stop member stop structures and projects the counter-stop part at least partially zwisehen in the area the stop structures, so that the path of the piston rod can be limited in both directions. With only one stop member thus the way in both directions of the piston can be limited, whereby the potential applications of the cylinder-piston unit can be increased.

Preferably, the stop structures are in the form of lugs which protrude radially outward with respect to the cylinder. This is a particularly simple way to create limits on the opposite directions without increasing space requirements.

Preferably, the counter-abutment part is arranged at the level of the cylinder. In this case, the counter-stop part enclose the cylinder or be arranged next to the cylinder, whereby a particularly compact design is achieved.

Preferably, the counter-abutment part is rotatable about the longitudinal axis of the cylinder. This represents a particularly space-saving and easy-to-use design.

Preferably, the counter-stop member is formed in the form of a sleeve enclosing the cylinder. Since the thickness of the sleeve wall can be kept low, the space required is further reduced by this design. In addition, this results in a compact design.

Preferably, the different limit stops are formed by a step-shaped wall of the sleeve. The counter-abutment can thus be made compact and easy. The steps in the wall can e.g. be formed in a wall recess which opens in the axial direction. Alternatively, the steps could be axial protrusions.

Preferably, the counter-stop part in the form of the sleeve, together with the integrated limit stops, is manufactured in one piece.

Preferably, a seated on the cylinder holder is provided for axially holding the counter-abutment part. Here, the cylinder assumes the additional function of holding the Against the stop member. The holder can be attached directly or indirectly to the cylinder.

Preferably, the holder is formed from at least two axially spaced-apart, radially outwardly projecting projections, between which the counter-stop member is inserted, resulting in a reliable axial fixation.

Preferably, the projections at least partially run around the cylinder. In addition to a simple production of the fixation of the counterpart stop part is ensured. Its rotatable bearing relative to the cylinder is positively influenced by the projections.

Preferably, the second portion of the stop member is guided by the projections in the axial direction. The projections thus assume a further function, resulting in a particularly compact and protected from wear structure.

Preferably, the holder is formed on an intermediate sleeve arranged between the counter-abutment part and the cylinder, on which the counter-abutment part is rotatably mounted. A conventional cylinder-piston unit can be easily retrofitted in this way, in which the cylinder adapted to the sleeve intermediate sleeve together with counter stop and stop member are placed on the cylinder.

Preferably, the counter-abutment part is rotatable about an axis of rotation, which is arranged laterally spaced from the cylinder and is substantially parallel to the cylinder longitudinal axis. In this embodiment, the counter-stop member is separately and spaced from the cylinder accessible.

Preferably, the counter-stop member is formed as a drum whose longitudinal axis coincides substantially with its axis of rotation. A drum is easy to handle and provided with various limit stops.

Preferably, the limit stops are formed on one end face of the drum as sector-wise graduations. The limit stops are thus integrally formed in the counter-stop part.

Preferably, a lower portion of the cylinder is connected to a lower portion of the rotation axis via a first connection member, and an upper portion of the cylinder is connected to an upper portion of the rotation axis via a second connection member. This results in a stable construction which prevents relative displacement between the cylinder and the counter-abutment part.

Preferably, a passage is provided in one of the connecting elements, through which the stop member is passed. By this construction, the stop member is better protected from external mechanical influences and the implementation can even serve as an axial guide for the stop member.

Preferably, the second portion of the stop member between the cylinder and counter-stop part. The stop member may extend entirely or only partially between the cylinder and stop member. In addition to a compact design, the stop member can thereby be guided and / or better protected against mechanical influences.

Preferably, the counter-stop member is manually rotatable, so that a simple adjustment of a certain limit stop can be made in the path of the stop member. The stop combination can be adjusted by hand relatively fast and repeatable.

The counter-abutment part preferably cooperates with a latching device with which the rotational positions of the counter-abutment part assigned to the respective abutment pairings can be arrested. This prevents an already set limit stop, e.g. shaken out of position.

Preferably, the latching device comprises a preferably spring-loaded ball pressure piece. This constitutes a simple and reliable variant. The latching device allows the counter-stopper to be frictionally engaged in any position (for example in the case of a drum or sleeve in each sector).

Preferably, this comprises the cylinder-piston unit means for measuring the distance covered piston travel (position measuring system for cylinder position). In addition to the Hubbegrenzungseinrichtung thereby the set piston travel can be checked.

Preferably, the cylinder-piston unit comprises means for measuring the relative rotational position of the counter-abutment part, in particular in the form of an angle measuring device (displacement measuring system for drum or sleeve angle). This makes it possible to check whether the desired stop pairing has been set correctly.

Preferably, the cylinder-piston unit is pneumatically actuated and thus represents a pneumatic drive with multiple end stops. Especially with pneumatically actuated cylinders, the invention Hubbegrenzungseinrichtung represents a special complement to your applications.

A preferred application of a cylinder-piston unit according to the invention is a bending machine for bending in particular flat workpieces with a lower tool (or die) and an upper tool, which are movable towards each other by a first drive to effect the bending operation. A second drive is intended to move the lower tool as such, e.g. to adjust or adapt to different workpiece sizes. For this shift, a cylinder-piston unit according to the invention could now be used as the second drive. The axis defined by the second drive is usually also referred to as the I-axis. A cylinder-piston unit according to the invention is much cheaper than a CNC-controlled drive and much easier to use than previous pneumatic I-axes.

The cylinder drive can thus be used efficiently and safely for the I-axis movement of a bending machine.

Finally, it should be emphasized that the embodiments without loose or loose projecting parts can be realized with a positive influence on life and handling.

A particular embodiment includes attaching to a pneumatic cylinder a mechanism partially attached to the movable system or partially to the fixed system. Fixed and moving parts have different end stops with each other. The mechanism can be adjusted so that the end stops (measured in the stroke direction) change digitally.

In one implementation example, there is a drum (counter-stopper part) which has two matching, predefined end stops in its sectors. The drum is in the fix system. A fork (abutment member) having two abutment surfaces / structures is coupled to the movable system. The drum can be rotated by hand and thus the different pairs of stops are set.

You can divide this drum lengthwise 2 to get double stop combinations.

In another implementation example is a (compact) cylinder with adjacent stop mechanism.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

Fig. 1

eine Zylinder-Kolben-Einheit;

Fig. 2

die Zylinder-Kolben-Einheit aus Fig. 1 mit unterschiedlich stark ausgefahrener Kolbenstange;

Fig. 3

eine Ausführungsform einer erfindungsgemäßen Zylinder-Kolben-Einheit;

Fig. 4

die Zylinder-Kolben-Einheit aus Fig. 3 mit unterschiedlich stark ausgefahrener Kolbenstange;

Fig. 5

die Zylinder-Kolben-Einheit aus Fig. 3 mit teilweise aufgeschnittenem Anschlagmechanismus ;

Fig. 6

die Zylinder-Kolben-Einheit aus Fig. 3 mit teilweise aufgeschnittenem Anschlagmechanismus, wobei die Schnittebene in Bezug zur Schnittebene der Fig. 5 um 90° geneigt ist;

Fig. 7

eine Zylinder-Kolben-Einheit im Schnitt entlang der Zylinderlängsachse.

Each shows in a highly schematically simplified representation:

Fig. 1

a cylinder-piston unit;

Fig. 2

the cylinder-piston unit off Fig. 1 with differently strong extended piston rod;

Fig. 3

an embodiment of a cylinder-piston unit according to the invention;

Fig. 4

the cylinder-piston unit off Fig. 3 with differently strong extended piston rod;

Fig. 5

the cylinder-piston unit off Fig. 3 with partially cut stop mechanism;

Fig. 6

the cylinder-piston unit off Fig. 3 with partially cut stop mechanism, wherein the cutting plane in relation to the cutting plane of Fig. 5 is inclined by 90 °;

Fig. 7

a cylinder-piston unit in section along the cylinder longitudinal axis.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or component names. Also, the location information chosen in the description, such as top, bottom, side, etc. related to the immediately described and illustrated figure and are to be transferred to the new situation mutatis mutandis when a change in position. Furthermore, individual features or combinations of features from the different exemplary embodiments shown and described can also represent independent, inventive or inventive solutions.

The embodiments show possible embodiments of the cylinder-piston unit, it being noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but also various combinations of the individual embodiments are mutually possible and this variation possibility due to the teaching technical action by objective invention in the skill of working in this technical field expert. So are all conceivable embodiments, which are possible by combinations of individual details of the illustrated and described embodiment variant, includes the scope of protection.

Fig. 1 and 2 show a cylinder-piston unit 1. A displaceably arranged in the interior of the cylinder 2 piston is connected to the protruding at the end face of the cylinder 2 piston rod 3 (similar to the reference Fig. 7 shown). The cylinder 2 defines a cylinder longitudinal axis 20. Fig. 1 shows an extended position of the piston rod 3 and Fig. 1 a retracted position of the piston rod 3. The cylinder-piston unit 1 has a variably adjustable Hubbegrenzungseinrichtung in the form of a stop mechanism 5, which comprises a stop member 6 and a counter-stop member 11.

The stop member 6 is fixed with a first portion 7 on a protruding from the cylinder 2 part of the piston rod 3 and cooperates with a second portion 8, which extends outside along the cylinder 2, in the respective stop position with the counter-stop member 11 together.

The counter-abutment part 11 is - viewed in the axial direction - arranged at the height of the cylinder 2 and axially fixed with respect to the cylinder 2. The counter-stop member 11 is rotatable relative to the stop member 6, wherein stop member 6 and counter-stop member 11 depending on the relative rotational position form different pairs of stops, through which the path of the piston rod 3 can be limited to different degrees.

The counter-abutment part 11 is rotatable relative to the cylinder 2 and forms different limit stops 12, which are each assigned to the different stop pairings. The counter-abutment part 11 can each form different limit stops on both of its end faces, which are axially spaced apart relative to the cylinder longitudinal axis 20, so that the travel of the piston rod 3 can be limited to different degrees in both directions.

The second portion 8 of the stop member 6 is formed by an elongate arm which extends substantially parallel to the longitudinal axis 20 of the cylinder 2, and has two with respect to the cylinder longitudinal axis 20 axially spaced apart, with the counter-stop member 11 cooperating stop structures 9, 10. The counter-abutment part 11 projects with a peripheral part into the area between the stop structures 9, 10, so that the travel of the piston rod 3 can be limited in both directions. The stop structures 9, 10 are in the form of lugs which project radially outward with respect to the cylinder 2.

In the illustrated embodiment, the counter-abutment part 11 is rotatable about a rotation axis 19, which is arranged laterally spaced from the cylinder 2 and is substantially parallel to the cylinder longitudinal axis 20.

The counter-abutment part 11 is designed in the form of a drum whose longitudinal axis substantially coincides with its axis of rotation 19. The different limit stops 12 are formed on a front side of the drum as a sectoral gradations. You can see them in the Fig. 1 and 2 only the upper limit stops 12, but can also be provided on the lower end side of the drum correspondingly formed limit stops (for the lower stop structure 9). The drum may also be formed 2-divided along its length to obtain double stop combinations. In this embodiment, the counter-abutment part 11 is formed of two mutually rotatable portions, wherein one of the two end faces of the mating stop member 11 is formed on the one of the two sections and the other end face of the mating stop member 11 is formed on the other portion. In the Fig. 1 and 2 the upper portion is rotatable against the lower portion (indicated by a dividing line).

A lower portion of the cylinder 2 is connected to a lower portion of the rotation shaft 19 via a first connecting member 21, and an upper portion of the cylinder 2 is connected to an upper portion of the rotation shaft 19 via a second connecting member 22. As a switching element can, for example, as in the Fig. 1 and 2 serve a rod which extends between the first and second connecting element and whose longitudinal axis preferably coincides with the axis of rotation 19.

In the upper connecting element 22, a passage 23 is provided, through which the stop member 6 is passed. Out Fig. 1 and Fig. 2 it can be seen that the elongated second portion 8 of the stop member 6 between cylinder 2 and counter-stop member 11 extends.

In the Fig. 3 to 6 is shown another independent embodiment of a cylinder-piston unit 1, wherein in turn for the same parts the same reference numerals or component designations as in the preceding Fig. 1 and 2 be used. To avoid unnecessary repetition, will also refer to the detailed description in the previous Fig. 1 and 2 referred or referred. The piston rod is in Fig. 3 retracted and in Fig. 4 extended while in the FIGS. 5 and 6 the stop mechanism is shown in part 'cut open'. As a supplement shows Fig. 7 a section along the cylinder longitudinal axis 20 and the piston 2 movable in the cylinder 4.

In the embodiment of the Fig. 3 to 6 the counter-abutment part 11 is rotatable about the longitudinal axis 20 of the cylinder 2 and also forms different limit stops 12, 13, which are each associated with the different stop pairings.

The counter-abutment part 11 forms on both of its end faces, which are axially spaced from each other with respect to the cylinder longitudinal axis 20, in each case different limit stops 12, 13, so that the travel of the piston rod 3 can be limited to different degrees in both directions.

The first portion 7 of the stop member 6 is a disc in the example shown, which is pushed with its central opening on the piston rod 3 and fixed there by means of nuts.

The second portion 8 of the abutment part 6 is formed by two substantially mutually parallel arms extending along opposite sides of the cylinder 2 and extending substantially parallel to the longitudinal axis 20 of the cylinder 2. The stop member 6 has here the shape of a fork.

Also in this embodiment, the second portion 8 of the stop member 6 has two with respect to the cylinder longitudinal axis 20 axially spaced, cooperating with the counter-stop member 11 stop structures 9, 10 (eg in the form of radially outwardly projecting lugs), wherein the counter-stop member 11 partially in the area between the stop structures 9, 10 protrudes, so that the path of the piston rod 3 can be limited in both directions.

The counter-abutment part 11 is formed in the form of a cylinder 2 enclosing and rotatable about the cylinder sleeve 14. The different limit stops 12, 13 on the upper and on the lower end face of the sleeve 14 are formed by a step-shaped wall of the sleeve 14.

Also in this embodiment, the counter-abutment part 11 could be formed from two mutually rotatable sections, so that the upper limit stops 12 and the lower limit stops 13 are additionally rotatable against each other (about the cylinder longitudinal axis).

For axially holding or fixing the counter-abutment part 11, a holder 15 seated on the cylinder 2 is provided. The holder 15 is formed from at least two axially spaced-apart, radially outwardly projecting projections 16, 17, between which the sleeve 14 is inserted. The projections 16, 17 run at least partially around the cylinder 2. The two arms of the second portion 8 of the stop member 6 are guided in the interrupted portions of the projections 16, 17 in the axial direction. The holder 15 with the projections 16, 17 is formed on a disposed between the counter-stop member 11 and the cylinder 2 intermediate sleeve 18, on which the counter-abutment member 11 is also rotatably mounted.

As in the first embodiment, here too the second section 8 or the arms of the abutment part 6 extends in sections between the cylinder 2 and the counter-abutment part 11.

The invention is not limited to the embodiments described above and further embodiments are possible. For example, the counter-stop member 11 may be manually rotatable. Also, the counter-abutment part 11 cooperate with a latching device, with which the respective stop pairings associated rotational positions of the counter-abutment part 11 can be locked. Such a latch can e.g. a preferably spring-loaded ball pressure piece, which can engage in corresponding, the stop pairings associated recesses in the counter-stop.

The cylinder-piston unit 1 can additionally comprise a device for measuring the recessed piston travel and / or a device for measuring the relative rotational position of the counterpart abutment part 11, in particular in the form of an angle measuring device.

The solution according to the invention has proven particularly useful with pneumatically actuated cylinders, but all other types of cylinders are also encompassed by the invention.

For the sake of order, it should finally be pointed out that, for a better understanding of the structure of the cylinder-piston unit, these or their components have been shown partly out of scale and / or enlarged and / or reduced in size.

The task underlying the independent inventive features and solutions can be taken from the description.

Above all, the individual in the Fig. 1, 2 ; 3, 4 . 5, 6 and 7 illustrated features form the subject of independent, inventive solutions. The relevant objects and solutions according to the invention are to be taken from the description and the detailed descriptions of these figures.

REFERENCE NUMBERS

1

Cylinder-piston unit

2

cylinder

3

piston rod

4

piston

5

stop mechanism

6

stop part

7

section

8th

section

9

stop structure

10

stop structure

11

counterstop

12

limiting stop

13

limiting stop

14

shell

15

bracket

16

head Start

17

head Start

18

intermediate sleeve

19

axis of rotation

20

cylinder longitudinal axis

21

connecting element

22

connecting element

23

execution

Claims (17)

1. A cylinder-piston unit (1), the piston (4) of which is connected to a piston rod (3) which projects out at an end side of the cylinder (2) and has a variably adjustable stroke limiting device in the form of an stop mechanism (5) which comprises a stop part (6) and a counter stop part (11), wherein the stop part (6) is fastened by way of a first section (7) to a part of the piston rod (3), which projects out of the cylinder (2), and interacts by way of a second section (8), which runs along the outside of the cylinder (2), in a stop position with the counter stop part (11), and wherein the counter stop part (11) is held axially with respect to the cylinder (2), and wherein the counter stop part (11) is rotatable relative to the stop part (6), wherein stop part (6) and counter stop part (11), in dependence of the relative rotational position, form different stop pairs by means of which the path of the piston rod (3) can be limited to a varying extent, characterized in that the counter stop part (11), in two regions which are axially spaced apart from one another with respect to the longitudinal cylinder axis (20), forms in each case different limit stops (12, 13) such that the path of the piston rod (3) can be limited in both directions to a varying extent.
2. The cylinder-piston unit according to claim 1, characterized in that the counter stop part (11) is rotatable relative to the cylinder (2) and/or forms different limit stops (12, 13) which are in each case associated with the different stop pairs.
3. The cylinder-piston unit according to claim 1 or 2, characterized in that the two regions, which are axially spaced apart from one another with respect to the longitudinal cylinder axis (20) and on which in each case different limit stops (12, 13) are formed, are the two end sides of the counter stop part (11).
4. The cylinder-piston unit according to claim 3, characterized in that the counter stop part (11) is formed from two sections which can be turned with respect to one another, wherein one of the two end sides of the counter stop part (11) is formed on the one of the two sections and the other end side of the counter stop part (11) is formed on the other section.
5. The cylinder-piston unit according to any one of the preceding claims, characterized in that the second section (8) of the stop part (6) is formed by at least one elongated arm which extends essentially parallel to the longitudinal axis (20) of the cylinder (2) and/or that the second section (8) of the stop part (6) is formed by at least two arms which extend essentially parallel to each other and which run along opposite sides of the cylinder (2).
6. The cylinder-piston unit according to any one of the preceding claims, characterized in that the second section (8) of the stop part (6) has two abutment structures (9, 10) which are axially spaced apart from each other with respect to the longitudinal cylinder axis (20) and interact with the counter stop part (11), and that the counter stop part (11) projects at least partially into the region between the abutment structures (9, 10) such that the path of the piston rod (3) can be limited in both directions.
7. The cylinder-piston unit according to any one of the claims 2 to 6, characterized in that the counter stop part (11) encloses the cylinder (2) or is arranged beside the cylinder (2).
8. The cylinder-piston unit according to any one of the preceding claims, characterized in that the counter stop part (11) is formed in the form of a sleeve (14) enclosing the cylinder (2) and is rotatable about the longitudinal axis (20) of the cylinder (2), wherein the different limit stops (12, 13) are preferably formed by a step-shaped wall of the sleeve (14).
9. The cylinder-piston unit according to any one of the preceding claims, characterized in that a holder (15) located on the cylinder (2) is provided for axially holding the counter stop part (11), wherein the holder (15) is formed from at least two projections (16, 17) which are axially spaced apart from each other and project radially outwards and between which the counter stop part (11) is inserted.
10. The cylinder-piston unit according to claim 9, characterized in that the second section (8) of the stop part (6) is guided by the projections (16, 17) in the axial direction.
11. The cylinder-piston unit according to any one of the preceding claims, characterized in that a holder (15) located on the cylinder (2) is provided for axially holding the counter stop part (11) and that the holder (15) is formed on an intermediate sleeve (18) which is arranged between the counter stop part (11) and the cylinder (2) and on which the counter stop part (11) is mounted in a rotatable manner.
12. The cylinder-piston unit according to any one of claims 2 to 7, characterized in that the counter stop part (11) is rotatable about a rotation axis (19) which is arranged laterally spaced apart from the cylinder (2) and is essentially parallel to the longitudinal cylinder axis (20).
13. The cylinder-piston unit according to claim 12, characterized in that the counter stop part (11) is formed as a drum, the longitudinal axis of which essentially coincides with its rotation axis (19), wherein the limit stops (12) are preferably formed as sectoral steps on one end side of the drum.
14. The cylinder-piston unit according to claim 12 or 13, characterized in that a lower section of the cylinder (2) is connected at a lower section of the rotation axis (19) via a first connecting element (21), and an upper section of the cylinder (2) is connected at an upper section of the rotation axis (19) via a second connecting element (22), wherein preferably a passage (23), through which the stop part (6) is passed through, is provided in one of the connecting elements (22).
15. The cylinder-piston unit according to any one of the preceding claims, characterized in that the counter stop part (11) interacts with a locking mechanism by means of which the counter stop part's (11) rotational positions associated with the respective stop pairs can be locked in place.
16. The cylinder-piston unit according to any one of the preceding claims, characterized in that the cylinder-piston unit (1) comprises a device for measuring the relative rotational position of the counter stop part (11), in particular in the form of an angle measuring device.
17. The cylinder-piston unit according to any one of the preceding claims, characterized in that the counter stop part (11) is formed from two sections which can be turned with respect to each other, wherein the one region of the counter stop part (11), which forms different limit stops (12), is formed on the one of the two sections, and the other region of the counter stop part (11), which forms different limit stops (13), is formed on the other section.

Images