WO2006005549A2

WO2006005549A2 - Clamping device for printing cylinder

Info

Publication number: WO2006005549A2
Application number: PCT/EP2005/007434
Authority: WO
Inventors: Klaus KÖLLING
Original assignee: Kaspar Walter Gmbh & Co. Kg
Priority date: 2004-07-09
Filing date: 2005-07-08
Publication date: 2006-01-19
Also published as: WO2006005549A3; DE102004033332A1

Abstract

The invention relates to a clamping device for a printing cylinder, comprising two holders (11), arranged on a common axis, the holders (11) each comprising a recess (12) for housing one end (15) of the printing cylinder, with the recesses (12) thereof facing each other and mounted to be adjustable relative to each other, characterised in that at least one of the recesses (12) has an inner contour with three offset mounting surfaces (13), on which the corresponding end (15) of the printing cylinder is held on clamping.

Description

Clamping device for printing cylinders

The invention relates to a clamping device according to the preamble of patent claim 1.

From EP 0 596 399 A1, a generic clamping device is known. Such devices are used, in particular Tief¬ pressure cylinder - z. B. for publication printing - to undergo a galvanic Ober¬ surface treatment. For this purpose, the ends of the gravure cylinders are clamped between two hollow cones serving as holders and facing each other. FIG. 1 shows a hollow cone described in EP 0 596 399 A1, which serves as a holder 1 and is installed in a galvanic plant in the manner described in EP 0 596 399 A1. The holder 1 is shown in FIG. 1 a) in section, in FIG. 1 b) in the front view and in FIG. 1 c) in perspective view. For clarity, a dashed axis end 2 ei¬ nes pressure cylinder is shown. In Fig. Ia) is clearly visible that the current from the holder 1 exclusively via an edge 3 of an end face of Achs¬ end 2 can be transmitted. The high current required for galvanic machining is then transmitted via the hollow cones (holder 1) and the edges which touch them to the front sides of the axle ends 2 in the printing cylinder. With a final diameter of about 100 mm and essentially even distribution of the current across the left and right axle ends, it is possible to inject up to about 14,000 A into the printing cylinder.

For these amounts of electricity, the solution described in EP 0 596 399 A1 has proved to be outstanding. With the development of broader Tiefdruck¬ cylinders with larger bale width and the use of electroplating baths with higher degrees of dipping of up to 100%, however, the need has arisen to transfer even higher currents - especially for chrome plating - in the Tiefdruck¬ cylinder to an economical Processing time to reach.

With such high amounts of current, however, there is a danger of overheating of the hollow cones holding the axle ends, which at worst can lead to fires on the hardened surface of the steel hollow cone, to the melting of insulating bushes and to electric arcs. The clamping device described in DE 101 21 937 A1 also makes it possible to transmit higher currents than before.

The invention is therefore based on the object to provide a clamping device for a printing cylinder, with which an improved contact between the axis end of the printing cylinder and the associated holder can be achieved to transmit higher amounts of electricity.

The object is achieved by a clamping device according to claim 1. Advantageous developments of the invention are defined in the dependent claims.

An inventive clamping device for a printing cylinder with two arranged on a common axis holders, wherein the holders each have a recess for receiving one end of the printing cylinder and are arranged with their recesses directed towards each other and are mounted undeliverable, is characterized in that at least one of Recesses has an inner contour with three vonein¬ other remote retaining surfaces on which the associated end of the printing cylinder is held during clamping.

The three mutually offset holding surfaces provide a kind of tripod beit, from which the associated axle end - can be clamped - similar to a three-jaw lining. Surprisingly, despite the reduced contact surface, significantly more current can be transmitted with a holder designed in this way, without the undesirable upper heating or arcing occurring. The reason for this is assumed that the z. B. in DE 101 21 937 Al described possible Abwälzbewegun¬ conditions between the holder and the axle end are prevented, since the axle end by the action of the tripod always at the three same Stel¬ len (holding surfaces) must rest.

It is particularly advantageous if the end of the printing cylinder is held exclusively on the holding surfaces. As a result, the function of the three-leg is guaranteed, without disturbing further holding surfaces, where local overheating could occur. It is particularly advantageous if the holding surfaces each cover a circle segment and are distributed uniformly, ie at an angle of 120 ° over the circumference of the recess. The even distribution supports the function of the "tripod".

In order to define the holding surfaces relative to the remaining inner contour, it is particularly expedient if the holding surfaces are raised relative to the rest of the inner contour and, in particular, protrude radially inward, ie form elevations with respect to the remaining inner contour. The remaining inner contour of the holder accordingly returns radially and can not come into contact with the axle end.

Preferably, the inner contour is designed substantially (hollow) conical or spherical segment segment. Already in EP 0 596 399 A1 and in DE 101 21 937 Al, the advantages of these forms, in particular with regard to the acceptance of different axial end diameters, have been described.

The retaining surfaces should be arranged on a lateral surface of a common, fictitious (imaginary) cone or ball segment. The shape of the remaining, existing between the retaining surfaces inner contour plays a rather subordinate role. However, in order to ensure a good heat dissipation from the contact points, it is desirable to bring the remaining inner contour as close as possible to the holding surfaces, without, however, accepting the risk of contact with the axle end.

In a particularly advantageous further development of the invention, at least one line element made of a material which differs from the rest of the material of the holder is inserted in at least one of the holding surfaces.

The material of the line element should have an improved current and / or thermal conductivity compared to the remaining material of the holder. For example, the material of the holder may be steel and the material of the conductor element may be copper. - A -

As a result, an improved contacting of the axle end is achieved on the relevant holding surface, so that even larger amounts of electricity can be transmitted. On the other hand, the line element supports the heat dissipation and thus cooling of the contact point due to its excellent heat-conducting property.

For further improvement, at least one additional element made of a material which differs from the rest of the material of the holder is used in at least one region of the holder between two holding surfaces. Like the line element, the additional element can also be made of a material which has a current and / or thermal conductivity which is improved compared to the rest of the material of the holder. In the additional element, especially the thermal conductivity plays a role, since the additional element can effectively contribute to the cooling of the entire holder. Accordingly, it is desirable to dimension the additional element as much as possible, but without impairing the strength of the holder.

Preferably, the line element is designed pin-shaped and inserted into the holder such that its exiting on the holding surface end face flush with the holding surface. Thus, in the holding surface, the current can be uniformly transmitted to the axle end.

In any case, it is expedient if the end face of the conduit element and / or the additional element is adapted to the inner contour of the recess and thus neither protrudes from the inner contour nor forms a depression.

Of course, the line elements can be used in all three retaining surfaces. Accordingly, it is also advantageous if in each case one or more additional elements are inserted between the three holding surfaces.

In another advantageous embodiment of the invention, the retaining surfaces are made entirely of a material that is different from the material of the rest of the holder. For this case, the z. B. from Kup¬ fer or a hard copper alloy existing line elements voll¬ constantly form the holding surfaces. However, it should be noted that When clamping the printing cylinder high forces and correspondingly high surface pressures occur on the holder, which may not be absorbed by the rela¬ tively soft copper.

These and further advantages and features will be explained in more detail below by means of examples with the aid of the accompanying figures. Show it:

Fig. 1 shows a known from the prior art holder in sectional view (a), front view (b) and perspective view

(C);

2 shows a holder according to the invention in sectional view (a), front view (b) and perspective view (c).

3 shows a further embodiment of the holder according to the invention in sectional view (a), front view (b) and perspective view (c).

Fig. 4 is a sectional view of a portion of a bearing bridge with the holder according to the invention.

2 shows a holder 11 according to the invention, which can be fastened to a bearing bridge to be described later in connection with FIG. 4.

The holder 11 essentially corresponds to the holder 1 described above with reference to the prior art in FIG. 1. It has a recess 12 in which an axis end 15 of a printing cylinder stylized by a dot-dash line can be recorded. The holder 11 is opposite and arranged on a common axis, a second, not shown holder assigned, so that the pressure cylinder can be clamped with its two axle ends 15 between the two holders 11. The holders 1 1 can be delivered to one another via the bearing bridge, so that the required clamping pressure can be generated.

The recess 12 has a substantially conical inner contour. However, the hollow cone of the inner contour is interrupted by three retaining surfaces 13, which are raised in relation to a remaining inner contour 14, ie protrude radially inwards toward the main axis.

Accordingly, the axle end 15 of the printing cylinder is only in contact with the three retaining surfaces 13, but not with the remaining inner contour 14, as shown in Fig. 2a) recognizable.

Through the three support surfaces 13, a kind of three-legged or three-jaw in-tension is generated, which ensures that the pressure cylinder and its axle ends 15 not rotate relative to the holder 11 and in particular to the support surfaces during rotation of the holder 11 with the pressure cylinder 13 moves. As it turns out, currents of over 20,000 A can be transmitted in this way.

FIG. 3 shows another embodiment of the invention, which, however, is based essentially on the embodiment described in connection with FIG.

In addition to the holder 11 shown in FIG. 2, a line element 23 is used in each case in a holder 21 in three holding surfaces 22. While the holder 21 is made of steel, the conduit member 23 may preferably be a copper pin.

The conduit member 23 is incorporated in the holder 21 such that it terminates flush with an end face in the associated holding surface 22, as in particular in Figs. 3a) and 3c) recognizable. Furthermore, the conduit member 23 extends in the holder 21 axially to an opposite end face 24 of the holder 21, where the conduit member 23 also terminates flush.

The line elements 23 have, on the one hand, the function of improving the current transmission and, on the other hand, the function of dissipating the heat arising at the contact point to the outside, that is to say in particular in the direction of the end face 24. The actual holding function is fulfilled by the restli¬ Chen, the conduit elements 23 surrounding retaining surfaces 22, which consist of steel and thereby required for a high contact pressure ensure mechanical strength.

Another embodiment of the invention is also shown in FIG.

Accordingly, as an alternative to the line elements 23 or additionally in the regions of the holder located between two holding surfaces 22, additional elements 25 are inserted in a manner similar to the line elements 23. Like these are the additional elements 25 z. B. copper pins, which are also incorporated flush with ih¬ ren end faces flush in the holder 21, as in Figs. 3a) and 3c) clearly visible.

The additional elements 25 improve the heat conduction from the contact points to the opposite end face 24 of the holder 21. Since they are used in mechanically less stressed areas of the holder 21, they can be dimensioned larger than the line elements 23 without the total strength to impair.

If it is possible to produce the line elements 23 from a harder material than copper, which at the same time has excellent current and thermal conductivity, the holding surfaces 22 can also be completely formed by line elements inserted into the holder 21.

Due to the high surface pressures acting in the holding surfaces 22, however, it will be preferable to harden the holder 21, which is otherwise made of steel, in order to achieve durability. The line elements 23 then only have the function of transmitting current and heat without having to perform any essential mechanical holding tasks.

4 shows a section of a part of a bearing bridge to which the holder 21 according to the invention is screwed. The Lagerbrük- ke shown in Fig. 4 is coaxially opposite in the Galvanikanlage assigned a second bearing bridge, so that the pressure cylinder between the two bearing bridges can be clamped.

The holder 21 is screwed to a shaft 30 which is rotatably mounted on a bearing 31 in a known manner. Opposite the shark ter 21, a current transfer region 32 is provided, in which water-cooled grinding carbons 33 introduce the galvanizing current into a slip ring 34, from where it is transmitted via the shaft 30 and the holder 21 to the impression cylinder.

The shaft 30 is fitted at the bearing point 31 into the actual bearing bridge, which ultimately holds the pressure cylinder or drives it in rotation and lowers it into the plating bath or lifts it out of the electroplating bath after the end of the plating process.

The shaft 30 is traversed by cooling channels 35 and 36 through which cooling water can be pumped. Through this cooling circuit and the front, the holder 21 supporting part of the shaft 30 is cooled. Since the line elements 23 provided in the holder 21 and, if appropriate, the additional elements 25 transfer the heat from the contact points on the holding surfaces 22 through the holder 21 to its rear end face 24, the heat can reliably flow from there through the cooling channels 35, 36 are discharged cooling circuit.

The structure shown in Fig. 4 represents a part of a known bearing bridge, so that a further description is unnecessary.

Claims

Patent claims

1. Clamping device for a printing cylinder, having two holders (11, 21) arranged on a common axis, wherein the holders (11, 21) each have a recess (12) for receiving one end (15) of the printing cylinder and with their recesses (12) are arranged directed towards each other and are supported to each other, characterized gekenn¬ characterized in that at least one of the recesses (12) has an inner contour with three mutually remote holding surfaces (13; 22), where the associated end (15 ) of the printing cylinder is held during clamping.

2. Clamping device according to claim 1, characterized in that the end (15) of the printing cylinder is held exclusively on the retaining surfaces (13, 22).

3. Clamping device according to claim 1 or 2, characterized gekennzeich¬ net, that the holding surfaces (13; 22) are evenly distributed over the circumference of Aus¬ recess (12).

4. Clamping device according to one of claims 1 to 3, characterized in that the holding surfaces (13; 22) each cover a circle segment.

5. Clamping device according to one of claims 1 to 4, characterized in that the holding surfaces (13, 22) are raised in relation to the remaining inner contour (14) and, in particular, protrude radially inwards.

6. Clamping device according to one of claims 1 to 5, characterized in that the inner contour is substantially conical or spherical segment-like.

7. Clamping device according to one of claims 1 to 6, characterized in that the holding surfaces (13; 22) are arranged on a lateral surface of a common fictitious cone.

8. Clamping device according to one of claims 1 to 6, characterized in that the holding surfaces (13, 22) are arranged on a lateral surface of a common, notional spherical segment.

9. Clamping device according to one of claims 1 to 8, characterized in that in at least one of the holding surfaces (22) at least one conduit element (23) is inserted from a material which differs from the remaining material of the holder (21).

10. Clamping device according to one of claims 1 to 9, characterized in that in at least one region of the holder (21) between two retaining surfaces (22) at least one additional element (25) is inserted from a material that differs from the remaining material of the holder (21).

11. Clamping device according to claim 9 or 10, characterized gekenn¬ characterized in that the material of the line member (23) and / or the additional element (25) has an over the remaining material of the holder (21) improved current and / or thermal conductivity ,

12. Clamping device according to one of claims 9 to 11, characterized in that the material of the holder (21) steel and the material of the line member (23) and / or the additional element (25) is copper.

13. Clamping device according to one of claims 9 to 12, characterized in that the conduit element (23) is pin-shaped and is inserted into the holder (21) such that its on the holding surface (22) austre¬ tend end side flush with the holding surface ( 22) completes.

14. Clamping device according to one of claims 9 to 13, characterized in that the end face of the conduit element (23) and / or the additional element (25) is adapted to the inner contour of the recess.

15. Clamping device according to one of claims 9 to 14, characterized in that the conduit element (23) and / or the additional zelement (25) in the holder (21) extends axially.