Patent Application
20190134687
The present invention relates to a rolling apparatus. More particularly this invention concerns such an apparatus used to make wire or rod.
A rolling apparatus is known having a first and a second rollers mounted in a frame. A workpiece passes through a nip between the rollers. Each of the rollers has a rolling surface that bears radially on the workpiece, and at least the first roller has a guide face that bears axially on the workpiece. In addition at least the first roller can be moved axially by a positioning assembly.
U.S. Pat. No. 3,934,446 describes a rolling apparatus for making wire in which a blank passes between two driven rollers and is subsequently extruded into a wire by a shaping die. The rollers guide the blank both radially and axially.
It is therefore an object of the present invention to provide an improved rolling apparatus.
Another object is the provision of such an improved rolling apparatus that overcomes the above-given disadvantages, in particular that makes a long service life of the rollers possible with simple means.
A rolling apparatus has according to the invention a frame and first and second roller mounted in the frame, rotatable about respective first and second axes, forming a nip through which a workpiece passes in a direction of travel, and each having a radially outwardly directed rolling surface that bears radially on the workpiece. The first roller has an axially directed first guide face that bears axially on the workpiece in the nip. A positioning assembly axially positions the first roller relative to the second roller. A shaping die is positioned axially downstream of the nip in the direction and receives the workpiece after it passes through the nip.
Thud the rollers press the workpiece through a shaping die immediately downstream of the nip of the rollers. In such an arrangement, adjustment of the guide face in a lateral and/or axial direction is also advantageous because it enables the precise centering of the workpiece relative to the die. The axial adjustability of the roller thus enables both the width and position of the roller nip to be adjusted.
For the same reasons, according to a generally preferred rolling apparatus according to the invention at least one, particularly two rollers are also adjustable radially.
In a simple and especially embodiment of the invention, each of the rollers has a guide face that bears on the workpiece axially. In particular, the two rollers can be embodied so as to be substantially mirror images of each other.
It is generally advantageous if each of the rollers can be variably positioned axially by a respective one of the positioning assemblies, thus allowing for comprehensive adjustment of the roller nip in terms of width and position.
In an embodiment of the invention that can be easily and reliably implemented, the positioning assembly comprises a spacer with defined dimensions by means of which an axial position is defined for the roller on respective drive shaft to which it is splined. The spacer works with a stop for the respective roller on the shaft that is fixed axially on the respective drive shaft. By providing a commensurately tightly stepped set of spacers, the width and/or position of the roller nip can be adjusted with minimal effort.
In an alternative embodiment of the invention, the positioning assembly can also comprise a continuously adjustable stop member that makes arbitrary and/or continuous positioning of the shaft possible. The stop member can be an adjusting nut, for example.
It is generally advantageous if at least a core of the workpiece is in a partially liquid state when entering the roller nip. This allows for a particularly low rolling force and, in conjunction with the shaping by a die, also imparts an especially advantageous microstructure to the molded and cooled workpiece. A partially liquid state is understood here to mean that the material of the workpiece is at a temperature within the melting interval of the respective alloy.
A rolling apparatus according to the invention is particularly well suited for shaping workpieces that are made of a non-ferrous metal. More preferably, the workpiece is made of a light metal and, especially preferably, of a magnesium and/or an aluminum alloy. Particularly the combination of a magnesium alloy and/or an aluminum alloy with extrusion through the die in a partially liquid state yields good results. This is especially true if the roller nip is exactly centered on the die by the adjustment option according to the invention.
Additional advantages and features follow from the embodiment described below as well as from the claims.
The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:
As seen in
Thus an axially and radially delimited and/or closed roller nip 9 through which a workpiece 10 is conveyed in a travel direction D by rotation of the rollers 1 and 2 is formed by the radially confronting rolling surfaces 5 and 6 and the axially confronting guide faces 7 and 8.
A die 12 through which the partially molten workpiece 10 is pushed or extruded for shaping is positioned directly downstream of the narrowest point of the roller nip 9. The die is so close to the rollers 1 and 2 and fits with them such that the workpiece 10 cannot escape laterally. Downstream of the die 12 is a tubular outlet guide 13 for guiding and cooling the extruded workpiece 10.
The workpiece 10 preferably enters the roller nip 9 in a partially liquid state. This applies at least to a core of the workpiece 10, with it being possible for an outer-surface part to already be solidified depending on the circumstances and process parameters. The partially liquid state is preferably achieved after melting and casting of the aluminum/magnesium alloy material to be extruded in the same heat.
Since the axially confronting guide faces 7 and 8 are in frictional contact with the workpiece 10 there is wear not only on the rolling surfaces 5 and 6 but also on these guide faces 7 and 8.
According to the invention, in order to restore the lateral delimitation of the roller nip 9 after wear, the rollers 1 and 2 can be adjustably positioned axially by respective positioning assemblies 14 on the shafts 3 and 4. The positioning assemblies 14 comprises respective spacers 15 and 16 against which the respective rollers 1 and 2 abut after being pushed axially onto the respective shafts 3 or 4. The selectably dimensioned spacers 15 and 16, in turn, abut against respective stops 17 and 18 that are fixed on the shafts 3 and 4.
The spacers 15 and 16 have defined axial dimensions, so that the axial positions of the rollers 1 and 2 on their shafts 3 and 4 are defined through appropriate selection of the spacer size. The rollers 1 and 2 positioned in this way are each held tightly by the respective spacers 15 and 16 against respective abutments 19 and 20. In this embodiment, the positioning assemblies 14 thus comprise the abutments 17, 18, 19 and 20 and the spacers 15 and 16. The rollers 1 and 2 are axially shiftable on the shafts 3 and 4 that are axially fixed and on which the abutments 17-20 are also axially fixed.
The system for positioning the shafts 3 and 4 and rollers 1 and 2 radially is not shown. This is achieved in a known manner via bearings holding the shafts 3 and 4. The overall height or radial dimension of the roller nip 9 can thus also be adjusted. In particular, this ensures that the workpiece 10 passes through the rollers 1 and 2 so as to be centered precisely in front of the die.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102017219577.0 | Nov 2017 | DE | national |
