DE2421644A1 - HYDRAULIC TENSIONER - Google Patents

Description

DR. ING. DIPL PHYS. H. STURiES

PATENT LAWYERS _n

DIPL. ING. P. EICHLER

56 WUPPERTAL 2, BRAHMSSTRASSE 29

3. wiai

Löckmann & Sohn, Verwaltungs GmbH., 5 Cologne 1, Hohe Str. 138 / I4o

" Hydraulic tensioner "

The invention relates to a hydraulic tensioner, consisting of a clamping body with a cylindrically offset Bore, a clamping piston guided in a sealed manner with a piston head widened in relation to the piston skirt, one located between the piston shaft and the wall of the larger diameter bore part, in an axial direction Direction of the bore shoulder on the one hand and the piston head shoulder on the other hand limited annular chamber and one which acts on the hydraulic pressure medium located therein via a supply line and is to be actuated by hand Pressure generator, in particular an adjusting screw with an adjusting piston.

Such hydraulic clamps are self-contained, self-sufficient clamping elements, as they are independent of external ones Supply lines or special pressure medium sources are and can be used for a wide variety of clamping and / or connection purposes. They guarantee it easy and safe clamping of e.g. workpieces

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or tools as well as the mutual bracing or joining of several objects, such as plates ο. like

In the known hydraulic tensioners of the above type, the adjusting screw forming the pressure generator is also included Adjusting piston arranged radially adjustable in the clamping body surrounding the clamping piston, namely in one side corresponding projecting projection of the clamping body, the bore chamber located in this projection for the actuating piston to be pushed in more or less far in it via its corresponding connecting line in the clamping body wall with the pressure medium ring chamber between the clamping body and the clamping piston in Connection. Such an arrangement of adjusting screw and adjusting piston in the clamping body thus requires a corresponding one Overall width of the clamping body or a corresponding lateral attachment to the clamping body. In addition, the Adjustment screw here also quite inaccessible, especially since it is not infrequently due to the above between the clamping body and a workpiece or the like clamped onto the end of the clamping piston protruding therefrom. Like. Is covered, so that the actuation of the adjusting screw is quite difficult here.

The invention is therefore based on the object of providing a hydraulic tensioner of the type in question to improve and perfect that

not
he has more of the aforementioned defects, rather of

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is extremely compact and can be handled much more easily, especially with regard to the Confirmation option of his pressure generator. This task is based on the hydraulic tensioner mentioned at the beginning according to the invention achieved in that the pressure generator and the pressure medium supply line leading to the annular chamber are arranged in the tensioning piston. In this way you get to a hydraulic tensioner, where the pressure generator is installed either in one or the other end of the tensioning piston without requiring additional space. Through this not only a compact design is achieved, but also the possibility of actuation for the pressure generator, in particular an adjusting screw provided with an adjusting piston, significantly improved, since the adjusting screw is on the end face of the clamping piston uncovered and therefore directly for the attachment of a corresponding actuation key accessible.

A hydraulic clamp that is structurally particularly compact and easy to use is achieved in particular when the tensioning piston provided with the built-in pressure medium generator and the pressure medium supply line is on its shaft part protruding from the clamping body is provided in a manner known per se with a screw thread and a clamping nut seated on it. A Such hydraulic tensioner is particularly suitable for mutual

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-A-

Clamping or connecting several with corresponding insertion or push-through openings for the clamping piston shaft provided objects between the clamping nut on the one hand and the face of the clamping body facing it on the other hand be clamped. In this case, it is particularly advisable to insert the pressure medium generator into the front end of the clamping piston surrounded by the chuck to be built in.

At its end of the bore that encompasses the clamping piston head, the clamping body is advantageously provided with a cover, which the Spannkorperbohrung or the sliding displacement therein Protects the clamping piston head against soiling and mechanical damage or the like.

According to another essential feature of the present invention is between the tensioning piston and the clamping body or its bore cover incorporated a resilience element. This ensures that after the depressurization of the hydraulic pressure medium, that is For example, when the adjusting screw is unscrewed, the tensioning piston automatically returns to its starting position returned to the clamping body. It goes without saying, however, that with simpler versions of the hydraulic tensioner on such a resilience element can also be dispensed with, since after corresponding depressurization of the hydraulic pressure medium loosened the clamping nut and

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the clamping piston can also be moved back relative to the clamping body by hand. As a spring-back device, for example, a normal helical compression springs can be used. But the resilience element can also consist of a resilient one Plastic cell bodies with in particular closed cells or pores consist, for example of a plasticized polyvinyl chloride.

Further features according to the invention as well as their

Advantages are described on the basis of several exemplary embodiments, which are shown in the drawing. 1 to 3 show hydraulic clamps with the free

Clamping piston shaft end of seated clamping nut,

Fig. 4 shows a hydraulic tensioner with a

Tensioning disk held by a screw fastening bolt, FIGS. 5 and 6 in section and in plan view

a hydraulic clamp with a cuboid clamping body,

Fig. 7 one with one as a Varlängungteil

serving, attached clamping tube provided hydraulic tensioner,

8 to 10 show further application or installation options for the new hydraulic tensioner, and FIG. 11 shows a hydraulic tensioner with both

Built-in pressure generators on the front of its clamping piston,

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Fig. 12th Fig. 13th Fig. 14th

a hydraulic tensioner with a pressure generator designed as a grease nipple, a hydraulic tensioner with tensioning piston which transmits tensioning pressures and a hydraulic tensioner with an as additional pressure generator serving grease press nipples.

The hydraulic tensioner shown in Fig. 1 consists essentially of the tensioning body 1 with a cylindrical stepped bore 2, a sealing piston 3 guided therein with a piston head 3 ^1f widened relative to the piston shaft 3 'and a piston head 3 1f at the end of the piston shaft 3' on a thread present here 3 ^ltf screwed clamping nut 4. Between the wall of the larger diameter bore part 2 'and the clamping piston shaft 3', the annular chamber 5 is provided, which is filled with a hydraulic pressure medium, eg oil, silicone, plastic compound, grease or the like. In the axial direction, the annular chamber 5 is delimited by the annular seals 6 and 7, which are attached to the bore ^{shoulder 2 ff} or to the shoulder 3 of the clamping piston head 3 ¹¹ . The bore 2 is closed by the cover 8, for example in the form of a cover cap, so that it is dust and dirt-proof to the outside.

In the end of the tensioning piston shaft 3 'surrounded by the tensioning nut 4 is the one serving as a pressure generator Adjusting screw 9 arranged together with the adjusting piston Io.

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The tensioning piston Io provided with the seal 11 seals against the chamber 12, which is connected to the annular chamber 5 via the pressure medium line in the tensioning piston 3. By appropriately screwing in the adjusting screw 9 with the aid of a to be inserted into its hexagon socket opening Socket wrench the actuating piston Io is pushed deeper into the chamber 12, whereby the inside as well as in the Connection line 13 and existing in the annular chamber 5 Pressure medium is placed under greater pressure prestress, so that the tensioning piston is subjected to tensile stress.

In the present exemplary embodiment, the hydraulic tensioner serves to mutually connect or clamp the two flat objects 14, for example two plates, which are pushed ^{over the tensioning piston shaft 3 1 with a corresponding insertion bore or an insertion slot 14 ′.} The clamping nut 4 is then tightened. Since only a low clamping pressure is necessary for this, this can also be done by hand if necessary. Finally, by actuating the adjusting screw 9 with the aid of a corresponding socket wrench, the pressure medium is put under pressure or greater preload, whereby the clamping piston 3 with its clamping nut 4 is displaced relative to the clamping body 1 and thereby the plates 14 between the clamping nut 4 and the one facing it

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End face 1 'of the clamping body 1 are firmly clamped.

To release this clamping connection, the adjusting screw 9 is turned back or slightly unscrewed, whereby a corresponding Pressure reduction in the hydraulic pressure medium takes place. Then the clamping nut 4 can be loosened.

The one in Pig. The hydraulic tensioner shown in FIG. 2 differs from the one shown in FIG. 1 mainly in that here the adjusting screw 9 and the adjusting piston Io are built into the clamping piston head 3 ″. In this case too, the tensioning piston 3 transmits corresponding tensile forces when the plates 14 are clamped. The cover cap 8 is here with an actuation opening 8 ^! provided for the adjusting screw 9. Furthermore, in this case, a spring-back element is provided between the tensioning piston 3 and the tensioning body 1 or its cover cap 8, which here consists of a cell body plastic ring 15, which preferably has closed cells or pores and consists, for example, of plasticized PVC. It not only seals the bore 2 between the clamping piston head 3 ¹¹ and the clamping body 1, but also causes the clamping piston 3 to perform a corresponding loosening movement relative to the clamping body 1 when the adjusting screw 9 is loosened, so that the clamping nut 4 can be loosened correspondingly more easily . The ring 15 can also be made of a rubber-elastic material such as rubber, butadiene or the like. exist. Other elastomers or foams can also be used for this.

In the embodiment example according to FIG. 3, the clamping body 1 and the clamping piston 3 are also designed as in the case of FIG. 1. What is different is that the

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Bore 2 in the clamping body 1 is covered at the rear by a screwed-on clamping base 8 ' ¹ with a clamping, in particular T-profile 8 ^{Ift seated thereon} . With the aid of this T-profile 8 ^ftt , the hydraulic tensioner can be pushed into corresponding T-grooves 16 'of clamping tables 16 or held therein. In the present case, it serves to clamp the workpiece 17 on the clamping table 16.

The hydraulic tensioner shown in FIG. 4 has, instead of a tensioning nut 4, a tensioning disk 18 'which is held by the screw bolt 18 which is screwed into the tensioning piston shaft 3'. By means of this screw bolt 18, the hydraulic clamp can easily be adapted to different workpieces or workpiece heights. The clamping ^{disk 18 f} is advantageously designed as a U-disk, that is, provided with a corresponding slot. This makes it possible to put the workpiece 17 'with its bore over the bolt 18, then insert the clamping disk 18' with its slot and then to actuate the hydraulic clamp. This leads to a very rational application. The adjusting screw 9 with the adjusting piston Io sit in the one with an extension continuation

set 3 provided head end 3 '' of the tensioning piston. The helical compression spring 19, which is supported on the one hand on the shoulder of the tensioning piston head 3 ′ ¹ and on the other hand on the cover cap 8, serves as the resilience element. The clamping body 1 is provided with a clamping groove 2o, via which it is pushed into the insertion slot of the table top 21, which is provided here with corresponding spring projections 21 '

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is. The object to be attached to the table top 21, e.g. the wheel body 17 ', only partially shown in broken lines, is tightened with the aid of the tensioning disc 18' after tightening the Screw bolt 18 and deeper screwing in of the adjusting screw 9 firmly pressed against the top of the table top 21, so the tensioning piston 3 in turn serves as a tension tensioner or has to absorb the corresponding tension forces.

- In the case of FIGS. 5 and 6, the clamping body 1 is not of a cylindrical shape, but of an essentially cuboid shape. It has screw fastening bores 22 at its four corners, which have correspondingly widened bore shoulders 22 at their ends in order to be able to receive the heads of appropriately designed fastening screws sunk so that the end faces of the clamping body 1 can be used as smooth clamping surfaces. The bore 2 present in the clamping body 1 is covered here by a membrane-like plate 23 which is held by the Seeger ring 24. In this as well as in other cases, a spring-back element, for example cellular plastic, can be accommodated between the cover 23 and the tensioning piston head 3 ^ff.

In the embodiment example according to FIG. 7, the hydraulic tensioner is used to clamp a particularly thick one Workpiece 17 ″ on the one provided with a T-slot 16 ′ Support table 16. For this purpose is provided with the built-in adjusting screw 9 and the adjusting piston Io The end of the clamping piston is provided with an extension 24 provided with an internal thread 23 in which the corresponding external thread

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provided clamping tube 25 is screwed. At the other end of the clamping tube 25, a clamping nut 4 is in turn screwed on. An actuating rod 26 extends axially through the tensioning tube and engages at its lower end in the hexagon socket of the adjusting screw 9 and at its upper end has an actuating head 26 'provided with a corresponding internal polygon. In this way, the hydraulic tensioner can also be used in the conventional manner for particularly thick-walled workpieces via the tensioning tube 25 and the actuating rod 26 arranged therein. By having several clamping tubes 25 and actuating rods 26 of different lengths, it is also possible to achieve various combinations of clamping tube 25 and actuating rod 26 and thus the greatest possible adjustment of the clamping length of the hydraulic clamp to the most varied of workpiece heights and shapes.

In the case of FIG. 8, the clamping body 1 is partially provided on its outer circumference with a screw fastening thread I ¹¹ or I ¹ ′ ¹ , with the aid of which the hydraulic tensioner can be screwed into corresponding threaded bores 27 of a mounting plate 28. The left half of FIG. 8 shows how the clamping body 1 can be screwed into the clamping plate 28 from below, whereas the right half illustrates the screwing of the clamping body 1 into the plate 28 from above. The clamping body 1 can of course also be provided with a screw fastening thread over its entire axial length.

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U 242 Ί 644

In Pig. 9 the hydraulic tensioner is used to fasten a preseeding disk 29 to the spindle 3o of a preseeding machine. ^{For this purpose, a union ring 31 is provided at the end of the clamping body 1} penetrated by the clamping piston shaft 3 1, which is fastened to the end face of the machine spindle 3o with the help of the screws 33 reaching through the fastening holes 32 and can center the hydraulic clamp. In the present case, the ring 31 forms with its shoulder 31 'at the same time the clamping abutment

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for the clamping nut 4 or the milling disk 29 clamped in between. The clamping piston 3 is under the action of the helical compression spring 19, di * = ¹ is supported here directly on the shoulder 3ο ^{1 of} the spin "del 3o the clamping nut 4 is tightened again slightly, while then by screwing in the adjusting screw 9 and moving the adjusting piston Io accordingly, the pressure medium is placed under greater pretension and the clamping piston 3 is accordingly acted upon is formed by its protruding head shoulder 3, here too - as in all other cases - correspondingly large clamping forces can be achieved by relatively easy turning of the adjusting screw 9.

In the case of Fig. Io is instead of a special one Coupling ring on the clamping body 1 for its direct front attachment to the machine tool spindle 3o Serving fastening flange 1 is provided, which is provided with corresponding screw fastening holes 32 is.

In the embodiment of FIG. 11 are

in each of the two ends of the tensioning piston 3 an adjusting screw 9 and an adjusting piston Io are installed, which are connected via the common Pressure medium connection line 13 in both the tensioning piston 3

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are connected to each other and to the annular chamber 5. Due to this double arrangement, depending on the installation conditions optionally one or the other adjusting screw 9 can be operated more conveniently. In addition, this is a double arrangement of the adjusting screws 9 and the adjusting piston Io to be adjusted by them in some cases also advantageous in that because it means that the individual Stellkolban has to be stowed away Io can be kept correspondingly lower or higher Clamping piston loading force ·? under otherwise the same Ratios are to be achieved.

In the case of FIG. 12, a pressure nipple is used as a pressure generator in one end of the tensioning piston 3 34 built in, the sirier appropriately designed for attachment Grease gun is used, which is requested by the appropriate of fat in the annular chamber 5 and in the connecting line 13 allowed to put existing pressure medium under correspondingly higher compressive stress. At the other end of the tensioning piston

3, a screw plug 35 is installed, which closes off the pressure medium outlet channel 37 via the valve ball 36 or allowed to open. By opening the channel 37 can sine corresponding amount of pressure medium from the channel 13 and d =? r Annular chamber 5 drained, hence the hydraulic tensioner be transferred into its release position, in which the clamping nut

4 is easy to move again.

Finally, there is also a hydraulic tensioner in FIG. 13

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shown, which differs from the cases described above does not act as a tension tensioner, but as a pressure tensioner,

that is, in which the clamping piston 3 present in the clamping body 1 is to be placed under pressure pretension with the aid of the hydraulic medium. ^{The clamping piston head 3 M} or its end face 3, which partially moves out of the clamping body 1, thus serves here as a pressure-transmitting clamping surface. The clamping body 1 is provided with an external thread and is screw-adjustable in a corresponding threaded bore 38 in one leg 39 'of a fork-shaped tool holder 39. In the present case, a turning tool 40 is fastened in the holder 39 with the aid of the hydraulic pressure clamp. Here, too, the clamping is expediently carried out in such a way that the turning tool 4o is initially only slightly fixed by loosely screwing the clamping body 1 into the bore 38 in the holder 39 and then set under correspondingly higher hydraulic clamping pressure by actuating the adjusting screw 9

In the embodiment according to FIG. 14, one end of the tensioning piston 3 is in turn an adjusting screw and adjusting piston 10 built in existing pressure generator, while at the other end a grease press or grease nipple is available, which makes it possible to generate additional pressure with a grease gun. This has the following advantages: Assuming a long tension path is required. For this, the travel of the adjusting screw 9 and the pressure piston 10 would have to be a multiple this length. The considerable overall length required for this

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but is not available in most cases. In such cases, an additional device with a grease nipple is required and grease gun as an auxiliary device are very welcome. It is then possible with the help of the grease gun to do most of the To bridge the clamping path in order to then additionally use the normal pressure generator in the form of the adjusting screw 9 and the adjusting piston 10 to achieve the required final pressure and thus the final clamping path to evoke.

As practice has shown, it is sometimes necessary that the annular chamber 5 delimiting seals 6 and 7 have a certain minimum distance from each other The volume of the annular chamber 5 is therefore not kept arbitrarily small can be. On the other hand, since practically all pressure media have compressibility, even if only low, this is the case The travel of the adjusting screw 9 to achieve a certain clamping pressure is correspondingly longer. To these travels therefore to shorten, the invention finally provides that in the annular chamber 5 between the two seals 6, 7 an inelastic filling body, e.g. a filling ring 41, which reduces the volume available to the pressure medium here is provided as shown in Fig. 13, for example. Such a Filling ring 41 can for example consist of metal or suitable plastic.

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Claims (25)

24216U Claims hydraulic tensioner consisting of the village in diameter larger bore part, Chult one tension body irit cylindrical stepped bore, a sealed therein guided clamping piston with respect to the piston shaft widened piston head, an intermediate dam Kolbsnschaft and the wall in the axial direction of the bore shoulder of a part, and the piston head, On the other hand, the annular chamber is limited and the hydraulic pressure medium located therein is acted upon by a supply line and can be operated manually, in particular an adjusting screw with an adjusting piston, characterized in that the pressure generator (9, lo) and the pressure medium leading to the annular chamber (5) - Feed line (13) are arranged in the tensioning piston (3). 2. Hydraulic tensioner according to claim 1, characterized in that the with the built-in pressure medium generator (9, lo) and the pressure medium supply line (13) provided clamping piston (3) on its from dam clamping body (1) protruding shaft part (3 ¹ ) with a Screw thread (3 ¹¹¹ ) and a clamping nut (4) sitting thereon is provided. (e.g. Fig. 1 to 3). 509846 / 0-238 3. Hydraulic clamp according to claim 2, characterized that the Druckirittelarzeuger (9, lo) in the front end surrounded by the clamping nut (4) of the tensioning piston (3) is installed (Fig. 1). 4. Hydraulic tensioner according to claim 2, characterized in that the pressure medium generator (9, lo) is built into the head end (3 ¹¹ ) of the tensioning piston (3) (Fig. 2). 5. Hydraulic clamp according to one of claims 1 to 4, characterized in that the clamping body (1) is provided with a cover (8) ^{on its bore end containing the clamping piston head (3 11) (e.g. FIG. 1).} 6. Hydraulic clamp according to claim 5, characterized that in the cover, e.g. a cover cap (8), an actuating opening (8 ¹ ) for the pressure generator (9, lo) built into the clamping piston head end (3 ¹¹ ) is present (e.g. FIG. 2). 7. Hydraulic clamp according to claim 5, characterized that the cover as a clamping base (8 ¹¹ ) is formed with a clamping, for example T-profile (8 ¹¹¹ ) seated thereon (FIG. 3). S09846 / 0238 8. Hydraulic tensioner according to claim I ₃ , characterized in that the pressure generator (9 _s lo) is installed in the head end (3 ^ft ) of the tensioning piston (3) provided with an extension extension (3) (Fig. 4). 9. Hydraulic tensioner according to claim 8, characterized in that in the _{end of the tensioning piston (3) opposite the pressure generator (9}} 10), a screw bolt (18) which also partially forms the tensioning piston shaft (3 ') is screwed, which has a preferably slotted tensioning disk ( 18 ') (Fig. 4). 10. Hydraulic tensioner according to claim 5 »characterized that between the clamping piston (3) and the clamping body (1) or its bore cover (8) Resilience element (15 or 19) is installed. 11. Hydraulic clamp according to claim 10, characterized shows that the resilience element consists of a helical compression spring (19) (Fig. 4). 12. Hydraulic clamp according to claim 10, characterized draws that the resilience member of a preferably at the same time also sealing elastomer, a rubber-elastic body or foam, in particular made of a plastic cell body (15) with closed cells or pores (e.g. Figures 2 and 11). 9846/0 238 13. Hydraulic clamp according to one of claims 1 to 12, characterized in that the Sparsnkörper (1) is designed cylindrical. 14. Hydraulic tensioner according to one of Claims 1 to 12, characterized in that the clamping body (1) is cuboid and at its four Corners are provided with screw mounting holes (22) (Figures 5 and 6). 15. Hydraulic clamp according to one of claims 1 to 14, characterized in that in the one provided with the built-in pressure generator (9, lo), provided with a corresponding internal screw thread (23) Tensioning piston end (24) is screwed into a tensioning tube (25) which has a screwed-on chuck (4) at its other end and an axially continuous operating rod inside (26) for the pressure generator (9, lo) contains. (Fig. 7) 16. Hydraulic clamp according to claim 13, characterized in that the clamping body (1) is at least partially provided on its outer circumference with a screw fastening thread (I ¹¹ or I ¹¹¹ ) (Fig. 8). 609846/0238 17. Hydraulic tensioner according to claims 1 to 3,
characterized in that on the end penetrated by the clamping piston shaft (3 ¹ ) = d = s clamping body (1) a union ring (31) which is used to mount it in e.g.
Screw mounting holes (32) is provided (Fig.
9). 18. Hydraulic tensioner according to claim 17, characterized
can ζ ei chnat that the clamping piston (1) is supported on the one hand at its head end (3 ¹¹ ) and on the other hand directly on a bore shoulder (3ο ¹ ) of the machine tool spindle (3o), in particular a return element
Screw pressure conveyor (19) is acted upon (Fig. 9). 19. Hydraulic tensioner according to claims 1 to 3, characterized
gekennzsi chnet that the clamping body (1) has a front attachment to, for example, machine tool spindles (3o) serving, provided with screw mounting holes (32) Mounting flange (1) is provided (Fig. Lo). 20. Hydraulic tensioner according to one of claims 1 to 7, characterized marked that in the two front ends of the tensioning piston (3) each has a set screw (9) with setting piston (lo), which are connected to each other and via a common pressure medium supply line (13) in the tensioning piston (3)
are connected to the annular chamber (5) (Fig. 11). 509646/0238 2421544 21. Hydraulic tensioner according to one of claims 1 to 19, characterized in that the pressure generator consists of one in one end of the tensioning piston (3) there is a built-in Pettpreßnipple (34) and a screw plug (35) is built into the other front end is the one with the pressure medium supply line (13) leading to the annular chamber (5) in connection with the pressure medium outlet channel (37) which opens into the clamping piston head front end (Fig. 12). 22. Hydraulic clamp according to one of claims 1 to 21, characterized in that the clamping piston head (3 ^fl ) can be partially withdrawn from the clamping body (1), its end face (3) serving as a pressure-transmitting clamping surface (Fig. 13). 23. Hydraulic tensioner according to claim 22, characterized characterized in that the clamping body (1) is provided on the outside with a screw fastening thread (38) and above it, for example, in one leg (39 ') of a fork-shaped tool holder (39) to be screw-adjustable is (Fig. 13). 24. Hydraulic tensioner according to one of claims 1 to 19, characterized in that in one end of the tensioning piston (3) an adjusting screw (9) pressure generator provided with adjusting piston (10) 609346/0238 24216U and in the other end a lubricating or grease nipple allowing the tensioning path of the tensioning piston to be varied (34) is installed (Fig. 14). 25. Hydraulic tensioner according to one of claims 1 to 24, characterized in that in the annular chamber (5) between the two seals (6,7) an inelastic filling body which reduces the volume available to the pressure medium here, e.g. a filler ring (41) is provided (Fig. 13) 509848/0238