EP2167257B1 - Ring press - Google Patents

Description

The present invention relates to a ring press according to the preamble of claim 1.

Ring presses are used for the production of dimensionally accurate sleeves, such as plain bearings, small motor housings, chain sleeves, chain rollers and the like. These sleeves are bent from strip material in a first step using a bending tool. This is usually a bending machine used. However, the roundness of the sleeve produced by bending does not yet have the desired accuracy within the tolerances of the finished product.

It is therefore necessary to press the pre-bent sleeve in a second step in a ring press under high pressure, so that the sleeve corresponds to the desired tolerances.

Ring presses according to the preamble of claim 1 are known and have, for example, four pairs each orthogonal to each other arranged pressing elements. At their radially outer ends, these pressing elements comprise roller-type or ball-type force transmission elements which are acted upon by pressure generating elements rotatable in the circumferential direction relative to the pressing elements when the pressing elements are in their pressing position. The movement of the pressing elements in the radial direction is, for example, by a on the respective role of a pressing element passing past, inclined pressure piece whose inclination is designed such that upon further rotation in the circumferential direction a greater pressure is exerted on the pressing element.

Furthermore, generic ring presses are known in which the pressure generating arrangement acts on the pressing elements via a hinge connection, in particular a kind of double ball joint between pressure generating arrangement and pressing element. In this case, the pressure generating arrangement and the pressing elements are connected to one another such that, depending on the rotational position of the pressure generating arrangement relative to the pressing elements, the pressing element is pressed into its pressing position or pulled into its release position. This type of ring press requires reciprocation of the pressure generating assembly to move the pressing members between the release position and the press position.

From the DE 42 06 260 A1 For example, there is known an annular press having a plurality of rollers that are unrolled to generate pressure over a continuous circumferential path formed by the respective radially outer edges of the press members.

A continuous circumferential path formed by the radially outer edges of the pressing elements allows continuous rolling movement of the rollers in one direction of rotation. A reciprocating movement of the pressure generating arrangement relative to the pressing elements is thus not required. In this case, pressure is transmitted from at least one of the rollers to a corresponding associated pressing element.

At the above manufacturing tolerances high demands are made and it accuracies in the range of 1/100-millimeters are required.

The object of the invention is to provide a ring press that meets the above tolerance requirements.

To solve this problem, a ring press according to claim 1 is proposed.

It is particularly preferred that the circumferential path has a profile which is regular in the circumferential direction and has alternating radial elevations and countersinkings, such that all rolling elements are moved synchronously into the pressing position when the rollers roll over an elevation.

Such a profile of the circumferential path allows for rolling the rollers in one direction of rotation also a repeated, repeated pressure generation on the workpiece. The profile can be designed such that it always has the same pressure generating characteristic regardless of the direction of rotation of the pressure generating arrangement. However, it is also conceivable that the elevations and depressions of the profile are designed to be direction-dependent, for example, such that the transition from a reduction in a survey is relatively weakly inclined to build up the pressure continuously and relatively slowly, and that the transition from the survey in the next reduction is relatively steep, so that the pressure on the workpiece quickly decreases. Depending on the desired manufacturing conditions, the profile can also be designed exactly the opposite, in order to obtain the highest pressure abruptly and then reduce it at the same rotational speed of the rollers slower.

So that the rollers can be unrolled on the circumferential path, the pressure generating arrangement preferably has a race on whose radial inner side the rollers roll off. The race, the rollers and the peripheral track thus form a kind of rolling bearing in which the race and the rollers roll relative to the circumferentially fixed pressing elements. The rollers are thus guided radially inward and can be rolled out over 360 °. This construction also has the advantage that the ring press is very compact.

In order to enable an adjustable preload, which is exerted by the race on the rollers and thus the pressing elements, it is proposed that the raceway is tapered on its radial outer side in the axial direction and abuts against the inside of a clamping ring of the pressure generating arrangement which is of opposite conical configuration in the axial direction. In this case, the clamping ring is preferably connected to a drive ring of the pressure generating arrangement, in particular screwed. Further, it is proposed in this context that the clamping ring in the axial direction relative to the race and the drive ring is adjustable to adjust the pressure acting on the workpiece.

The two conical, superimposed peripheral surfaces of the race and the clamping ring allow by axial movement of the clamping ring on the axially fixed race adjusting the radial direction acting on the pressing elements and thus the workpiece pressure. The adjustability can be in a range up to 0, 10 mm in the radial direction.

According to the invention, slot-like openings are formed in the pressing elements, in which stationary guide elements are received with respect to the pressing elements, which guide the radial movement of the pressing elements to the center of the dome or the ring press.

Thus, the rollers do not abut each other during rolling between the race and the continuous peripheral edge, it is proposed that between two circumferentially adjacent rollers each have a spacer is provided which is fixed to the race.

Preferably, the pressure generating arrangement, the pressing elements and the guide elements are supported immovably in the axial direction and are in particular on a base plate. In particular, the guide elements are attached to the base plate, preferably screwed. In order to hold the pressure generating arrangement, the pressing elements and the guide elements in the axial direction on the base plate, is preferably a Cover plate or a flange provided, which is or is screwed to the base plate, said screw particularly preferably passes through the guide elements and they are thus also fixed.

In order to rotate the pressure generating arrangement relative to the pressing elements, it is proposed to drive the pressure generating arrangement by an electric motor and a gear coupled thereto. In this case, the gearbox in particular has a pinion attached to a shaft of the electric motor which meshes with teeth formed on the outer circumference of the drive ring of the pressure generating arrangement. The electric motor may be mounted, for example, on the other side of the base plate supporting the pressure generating assembly, the pressing elements and the guide elements, the shaft of the electric motor passing through a corresponding bore in the base plate, so that the meshing between the pinion mounted on the shaft and the drive ring is possible.

In order to feed a workpiece over the mandrel of the ring press or to remove it from the ring press after the pressing process, it is proposed that the pressing elements are movable by return means from the pressing position to the release position when the rollers are in the subsidence of the profile of the continuous circumferential path ,

According to the invention it is proposed that in the ring press existing lubricating oil is used for restoring pressure generation. This is done by pressurizing lubricating oil, which is located in respective gaps formed between the guide member and a slot opening of a respective pressing member, in this space in the pressing position such that the built-up hydraulic pressure is sufficient to press the pressing member to move radially outwards relative to the guide element when the one of the Rolls on the pressing elements exerted pressure subsides.

The elevations and depressions in the profile of the continuous circumferential path are preferably arranged such that the elevations and depressions are arranged in the profile of the continuous circumferential path such that in each case a number n elevations are formed completely on the outer radial edge of each pressing element, that a number n 1 depressions are completely formed on each pressing element and that the still required to complete the profile reductions are formed in each case half in the circumferential direction directly adjacent pressing elements.

Particularly preferred is an embodiment in which the ring press 24 comprises rollers and eight pressing elements, so that in the pressing position in each case three rollers act on a pressing element. In order to enable the synchronous movement of the pressing elements, it is proposed that the number of rollers is equal to the number of protrusions per pressing element multiplied by the number of pressing elements, and that the number of counterbores is equal to the number of rollers or the total number of protrusions.

With reference to the embodiment with 24 rollers, this means that a pressing element n = 3 has elevations that are completely formed on the outer radial edge of the pressing element. The profile begins along the circumferential direction with a half countersink, then join the three surveys with each intervening complete subsidence and the profile is completed after the third survey by another half reduction. Now, if two pressing elements lie directly next to each other, the respective half-sinks in the transition region between the two pressing elements a complete reduction, so that over the entire circumference of the circumferential path the same number of complete elevations and full subsidence is formed.

Fig. 1

ist eine Draufsicht in Axialrichtung der Ringpresse, wobei die Ringpresse teilweise geöffnet dargestellt ist.

Fig. 2

ist eine Querschnittsdarstellung gemäß der Schnittlinie II-II.

Fig. 3

ist eine Vergrößerung der Schnittansicht der Fig. 2 oberhalb der Drehachse der Ringpresse.

Fig. 4

ist eine vergrößerte, perspektivische Ansicht der Rollenanordnung in der Ringpresse.

Fig. 5

ist eine vergrößerte perspektivische Ansicht eines Presselements.

The invention will now be described by way of example, not limitation Embodiment described with reference to the accompanying figures.

Fig. 1

is a plan view in the axial direction of the ring press, wherein the ring press is shown partially open.

Fig. 2

is a cross-sectional view along the section line II-II.

Fig. 3

is an enlargement of the sectional view of Fig. 2 above the axis of rotation of the ring press.

Fig. 4

is an enlarged perspective view of the roller assembly in the ring press.

Fig. 5

is an enlarged perspective view of a pressing member.

In the schematic plan view according to Fig. 1 a base plate 10 can be seen on which a pressure generating arrangement 12 is supported in the axial direction of a rotation axis D of the ring press. The pressure generating assembly 12 is driven via a pinion 14, which rotates counterclockwise with respect to the viewing direction in this embodiment, wherein the rotational movement of the pinion 14 via an in Fig. 2 shown toothing 15 is transmitted to a drive ring 16 of the pressure generating arrangement. The drive ring 16 is thus driven in the clockwise direction and transmits this direction of rotation to the other in the circumferential direction U movable elements of the pressure generating arrangement 12th

Along the inner circumference of the drive ring 16, a clamping ring 18 which is secured by means of screws 20 on the drive ring 16 extends. The drive ring 16 has, based on the cross-sectional view of Fig. 2 on its right side a radially inwardly extending projection 22 through which the screws 20 are passed. This radial Projection 22 forms together with the base plate 10 a receiving space in which a race 24 and rollers 26 are received. In the radial direction close to the rollers 26 a plurality of pressing elements 28, which are arranged in the circumferential direction next to each other and in the example at their radial outer end portions 29 and at their radial inner end portions 31 in the circumferential direction touch ( Fig. 4 . 5 ).

At their radially outer edge 30, the pressing elements 28 have a regular profile, which comprises alternately radial elevations 32 and countersinks 34, which is shown in the enlarged, perspective illustration of a single pressing element according to FIG Fig. 5 is apparent.

The pressing elements 28 have an oblong hole-shaped opening 36 through which a guide element 38 passes. This guide element 38 has a length in the radial direction which is slightly smaller than the length of the oblong hole 36, so that the pressing elements 28 can move in the radial direction relative to the stationary guide element 38. The guide elements 38 rest on the rear side on the base plate 10 and are held by means of a resting on the front of the drive ring 16 cover plate 40 in the axial direction. The cover plate 40 and the guide elements 38 are fixed by common screws 42 on the base plate 10, wherein the guide elements are also received in recesses.

The pressing elements 28 are moved by the rolling of the rollers 26 on the continuous circumferential path 46 in the radial direction R to a mandrel 48, on which a workpiece to be machined, in particular a sleeve 50, is pushed. The sleeve 50 is acted upon and pressurized by the radial inner edges 52 of the pressing elements 28 which each form a circular arc segment, so that the sleeve 50 is pressed into its final shape between the pressing elements 28 and the mandrel 50. The case generated by the ring press pressures are very high and amount to about 100 tons or more, which is a multiple, about 4- to 6 times, the pressure that can be generated by conventional ring presses. The particular metallic sleeve material usually comes in the flow area, so that an optimal and precise shaping is possible.

Due to the profiling, the pressing elements 28 are in a release position when the rollers 26 are located in a countersink 34. In this position, a sufficient distance between the mandrel 48 and the radial inner edges 52 of the pressing elements 28 is given, which allows the feeding of a workpiece or the release of an already pressed workpiece 50. When the rollers 26 are on a survey 32, the pressing elements 28 are pressed into their pressing position in which they press a sleeve 50 concentrically against the mandrel 48.

The mandrel 48 includes in its center the axis of rotation D of the pressure generating arrangement 12, in particular the circumferentially moving elements drive ring 16, clamping ring 18 and race 24. Preferably, the mandrel 48 in the release position of the pressing elements 28 is also rotatable about the axis D together with the In this way, those areas of the sleeve can be brought into shape, which lie in a first pressing step in the circumferential direction exactly between two adjacent pressing elements 28. It can thus be bridged other pressure points and joints with multiple pressing.

From the Fig. 2 It can be seen that on the back of the base plate 10, an electric motor 54 is mounted, the drive shaft 56 passes through the base plate and the pinion 14 carries. Furthermore, lubricant feeds 58 are formed in the base plate, can be supplied via the lubricant in the formed by the base plate 10, cover plate or flange 40 and drive ring 16 Ringpresseninnenraum.

The supplied lubricant is used in this embodiment as a return means for the pressing elements 28. If this by rolling the Rollers 26 are placed over the elevations 32 in the radial direction to the axis of rotation D out under pressure, lubricant, which is located in a formed between the slot 36 and guide member 38 intermediate space or chamber 60, also pressurized. This hydraulic pressure allows the press members 28 to be returned radially outward when the rollers 26 are in a counterbore 34 of the continuous circumferential path 46.

Referring to the enlarged cross-sectional view of referring to Fig. 2 Upper part of the pressure generating arrangement is from the Fig. 3 it can be seen that the clamping ring 18 and the race 24 have conical contact surfaces 62 and 64, respectively. Since the clamping ring 18 by means of the screw 20 with respect to the race 24 and the drive ring 16 in the axial direction is adjustable, can be adjusted by the interaction of the inclined contact surfaces 62, 64, a bias on the rollers and thus the pressing elements. This adjustability makes it possible to make radial adjustments in the range up to about 0.10 mm. The clamping ring 18 and the race 24 in principle form a wedge gear in which the rotational movements transmitted by the pinion 14 to the drive ring 16 by means of adhesion to the rollers 26 is transmitted.

In the Fig. 1 are still spacers 66 can be seen, which are mounted on the race 24. These spacers 66 hold the rollers 26 equidistant from one another and prevent the rollers 26 from approaching or being removed relative to one another when rolling in the circumferential direction. This ensures that always all rollers 26 are arranged simultaneously on a survey 32 or in a reduction 34 of the circumferential path 46, so that the pressing elements 28 are operated synchronously in the radial direction R.

Referring to Fig. 4 and 5 It should also be added that the elevations 32, which in the exemplary embodiment have the same gradients from a countersink 34 and down to a countersink 34, could also be designed differently. For example, one of the slopes could be steeper be executed when a sudden pressure increase or decrease is desired. Of course, such a rapid or slow pressure increase or decrease may also be controlled via the rotational speed of the pressure generating arrangement by means of a control unit of the ring press or a production machine unit comprising the ring press, not shown and explained here.

The pressing elements 28 have between the radially outer and radially inner end portions 29, 31 a recess 33 which serves to receive and distribute lubricant. Furthermore, the contact surfaces between the pressing elements 28 are reduced in the circumferential direction by this recess 33.

The number of times a workpiece 50 is pressurized during processing depends on the circulation rate of the pressure generating assembly. For example, in the embodiment shown, an eighth-turn of the pressure generating arrangement 12 leads to a three-times pressurization of the sleeve 50, since during such eighth rotation, the rollers 26 are unrolled over three elevations 32.

It should also be noted that in the embodiment 24 rollers 26 and as many elevations 32 and counterbores 34 are formed on the circumferential path 30. In this case, there are always three full elevations 32 and two intermediate elevations 34 on one pressing element 28. The remaining depressions 34 'are each formed by two adjacent pressing elements 28, on each of which half a countersink 34' is formed. It is of course possible to change both the number of pressing elements and the number of rollers and the number of elevations and reductions on the circumferential path. It is essential in such an adaptation that the rolling movement of the rollers over the elevations and depressions of the circumferential path enables the synchronous actuation of the pressing elements.

Claims (14)

1. Ring press, comprising
   a mandrel (48), by means of which an annular workpiece (50) to be pressed can be guided in axial direction to the ring press and on which the workpiece (50) can be supported,
   a plurality of pressing elements (28) guided in radial direction (R) by means of which pressure can be exerted onto the workpiece (50) supported on the mandrel (48), and
   a pressure generating arrangement (12) that is rotatable in circumferential direction relative to the pressing elements (28), during the rotation of which relative to the pressing elements (28) the pressing elements (28) are moved from a release position to a pressing position, wherein the pressure generating arrangement comprises a plurality of rollers (26) which are rolled to generate pressure over a continuous circumferential track (46) formed by the respective radial outer edges (30) of the pressing elements,
   characterised in that elongated hole-like openings (36) are formed in the pressing elements (28), in which openings guiding elements (38) are mounted that are fixed relative to the pressing elements (28), which guiding elements guide the radial movement of the pressing elements (28) to the centre of the mandrel (48) or the ring press, wherein the pressing elements (28) can be moved by hydraulic restoring means, which comprise the guiding elements (38) and the openings (36), from the pressing position into the release position, in that lubricating oil in the respective intermediate spaces, which are formed between a respective guiding element (38) and an opening (36), is put under pressure in the pressing position.
2. Ring press according to claim 1, characterised in that the circumferential track (46) has a regular profile in circumferential direction with alternately radial elevations (32) and depressions (34, 34') such that when rolling the rollers (26) over an elevation (32) all of the pressing elements (28) are moved synchronously into the pressing position.
3. Ring press according to claim 1 or 2, characterised in that the pressure generating arrangement (12) comprises a race (24) on the radial inner side of which the rollers (26) run.
4. Ring press according to claim 3, characterised in that the race (24) is configured to be conical on its radial outside (64) in axial direction and bears against the inside (62) of a tension ring (18) of the pressure generating arrangement (12) formed to be counter-conical in axial direction.
5. Ring press according to claim 4, characterised in that the tension ring (18) is connected to a drive ring (16) of the pressure generating arrangement (12), in particular is screwed to the latter.
6. Ring press according to claim 5, characterised in that the tension ring (18) can be adjusted in axial direction relative to the race (24) and to the drive ring (16) in order to adjust the pressure acting on the workpiece (50).
7. Ring press according to any one of the preceding claims, characterised in that between two rollers (26) that are adjacent in circumferential direction a spacer (66) is provided which is secured to the race (24).
8. Ring press according to any one of the preceding claims, characterised in that the pressure generating arrangement (12), the pressing elements (28) and the guiding elements (38) are supported non-displaceably in axial direction, in particular lie on a base plate (10).
9. Ring press according to claim 8, characterised in that the guiding elements (38) are secured to the base plate (10), in particular are screwed to the latter.
10. Ring press according to any one of the preceding claims, characterised in that the pressure generating arrangement (12) is driven by an electric motor (54) and a gear (14) coupled therewith.
11. Ring press according to claim 10, characterised in that the gear comprises a pinion (14) attached to a shaft (56) of the electric motor (54), which pinion meshes with teeth (15) formed on the outer circumference of the drive ring (16) of the pressure generating arrangement.
12. Ring press according to any one of claims 2 - 11, characterised in that the elevations (32) and depressions (34, 34') are arranged in the profile of the continuous circumferential track (46) such that a number n of elevations (32) are formed completely on the outer radial edge (30) of each pressing element (28), in that a number n-1 of depressions (34) are formed completely on each pressing element and in that the depressions (34') still required to complete the profile (30) are each half formed on pressing elements (28) directly adjacent to one another in circumferential direction.
13. Ring press according to claim 12, characterised in that it comprises 24 rollers (26) and 8 pressing elements (28) so that in the pressing position three rollers (26) act on a pressing element (28).
14. Ring press according to claim 12 and 13, characterised in that the number of rollers (26) is equal to the number n of elevations (32) per pressing element (28) multiplied by the number of pressing elements (28) and in that the number of depressions (34, 34') is equal to the number of rollers or the total number of elevations (32).

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