|Title of Invention||
A METHOD FOR PRODUCING A SPINNING OR TWISTING RING AND A SPINNING OR TWISTING RING
|Abstract||A disc is stamped out as a blank from a steel strip, is provided with a hump in its centre and is deep- drawn to form a cup-shaped blank. Subsequently, the hump is pressed flat and, at the same time, material is displaced into the edge zone which forms the flange region. After the pressed-flat bottom has been stamped -out, a flange region (70) is formed on the blank (12d) by means of an embossing and deep-drawing die (68) and is brought into the finished shape of a flanged ring by means of an embossing die. As a result of this method, chip-removing machining steps can be avoided and consequently the production costs can be reduced.|
Method for shaping a spinning or twisting ring and spinning or twisting ring produced without cutting
The invention relates to a method for shaping a spinning or twisting ring according to the pre-character-izing clause of Claim 1 and to a spinning or twisting ring produced without cutting and having a T-shaped profile.
The term "flanged ring", the parts of which are referred to as a flange and a web, is employed below in connection with the T-shaped profile. The flange faces, with which the traveller cooperates during the spinning or twisting operation and the profile accuracy and surface quality of which are important, are referred to below as functional faces or functional profiles.
Known methods for shaping a flanged ring consist, as a rule, of chip-removing operations. These take as a starting point tubular bars made from ball-bearing or casehardened steel. On multi-spindle automatic lathes or CNC machines, a corresponding annular profile is fashioned from a lathe-turned blank, the lathe-turned blank having to be formed by slicing.
Apart from the labour-intensive nature of these machining operations starting from tubular bar stock, the material fraction of the machined flanged ring is relatively small or the chip volume removed large in comparison with the quantity of initial stock required. The known methods are therefore costly and material-intensive, and this has a direct effect on the costs of a flanged ring.
The object of the invention is to provide a method for shaping a high-quality flanged ring, which is
efficient both in terms of the method operations and in terms of the consumption of material for it.
The invention lies primarily in the finding that a flanged ring with sufficient material displacement to form the flange can be achieved solely by strip forming, that is to say by drawing and pressing operations.
The solution for achieving the object according to the invention emerges from the characterizing clause of Claim 1.
Since the operations carried out according to the method lead to a flanged ring having a finished shape, manufacture is extremely cost-effective when appropriate quantities are produced. Chip-removing machining work is unnecessary, at least insofar as the essential dimensions of a flanged ring according to ISO 96-1:1992 (referred to there as a T-ring) are involved. The forming operations themselves, like the stamping operations, can be carried out without rechecking.
The operations associated with the shaping method can be followed by manufacturing steps known per se, such as casehardening and polishing. As regards the profiling work on the flange, this can be carried out by turning or grinding, in the latter case also after casehardening. A considerable saving of material is achieved in comparison with the production of flanged rings by cutting.
Since the upsetting operation and the operations which serve for shaping on the flange entail a compression of material, a flanged ring shaped according to this method also proves advantageous in terms of wear properties .
According to a preferred embodiment, the stamping operation for separating the circular disc is carried out
from the web side. Consequently, the shearing edge on the inward-projecting flange neck comes to rest against the flange top side, that is to say in a material zone which, even after pressing, is not located in a functionally essential part of the flange and does not undergo any load exerted by the traveller during the operation.
According to a further preferred embodiment, predetermined functional profiles are imparted to the edge regions of the flange by means of an extrusion operation. Remachining by turning or grinding can therefore be avoided completely. It has been shown that accurate profiling and a smooth surface of the functional faces can be achieved by means of these operations. The avoidance of any relevant refashioning by turning or grinding also allows a considerable cost saving. Finally, extrusion has a direct effect on the improvement in wear properties.
The invention also comprises a spinning or twisting ring which is produced completely without cutting by cold forming and which, according to the invention, has a solid wall and is also distinguished by a particular distribution of the grain sizes over the ring cross-section.
An exemplary embodiment of the invention is explained in more detail with reference to the drawings in which:
Figure 1 shows a portion of a steel strip with a reshaped blank disc held therein by lattice retention, Figure 2 shows the forming of a hump in the center of the blank disc by means of a first deep-drawing operation, Figure 3 shows a second deep-drawing operation to form the at least approximately cylindrical part of the ring
Figure 4 shows a drawing and ironing operation with a controlled flow of material and the pressing flat of the hump by cold extrusion into the edge region for reshaping the ring flange,
Figure 5 shows a detail of the edge region according to Figure 4 in an enlarged representation,
Figure 6 shows a follow-on stamping operation for the rough shaping of the ring inside diameter and for releasing the ring blank from the steel strip,
Figure 7 shows the edge region opposite the flange region and having the stamped edge according to Figure 6, in an enlarged representation,
Figure 8 shows an operation of embossing the non-functional stamped edge, the tapering of the outside diameter by drawing, a controlled flow of material into the flange region and the reduction of the web length in order to increase the availability of material in the flange region,
Figure 9 shows the tapering of the outside diameter by means of the rounded inner edge of the drawing die, represented in three successive views,
Figure 10 shows an extrusion operation for the final shaping of the functional faces of the flange region, and Figure 11 shows an exemplary embodiment of a flanged ring according to the invention.
In a steel strip 10, shown as a fragment in Figure 1, a partially stamped-out round disc is held as a blank disc 12 by means of a lattice retention 14a, 14b obtained by lattice stamping. A hump 16 is formed in the center of the blank disc 12, which forms the basis for a blank for manufacturing a spinning or twisting ring.
The first deep drawing die 22, shown in Figure 2 and having a bottom swage 18 and an upper swage 20, serves for forming the hump 16.
By means of the second deep-drawing die 28, shown in Figure 3 and having a bottom swage 24 and an annular upper swage 26, the blank disc 12 shown in Figure 2 is shaped to form a cup-shaped blank 12a, an at least approximately cylindrical wall being formed as a web region 30. In this step of the method, the blank 12a is still connected to the steel strip 10 by means of the lattice retention 14a, 14b shown in Figure 1, although the webs of the lattice retention 14a, 14b are drawn apart from one another in comparison with the illustration in Figure 1, since the outside diameter of the edge on the blank 12a becomes smaller as a result of the second deep-drawing operation.
The die 36, shown in Figure 4 and having a bottom swage 32 and an upper swage 34, serves for drawing and ironing the blank 12b and for pressing flat the hump 16 shown in Figure 2. By means of this die 36, on the one hand the web region 30a is stretched, so that its wall thickness 38 is reduced to, for example, 0.8 mm. On the other hand, when the hump 16 is being pressed flat, by cold extrusion, a controlled flow of material takes place in the direction of the arrow 40 according to Figure 5 out of the centre into the edge region 42. For this purpose, an annular depression 44 is arranged in the bottom swage 32. Although not shown, in this step of the method too, the blank 12b is still connected to the steel strip 10 according to Figure 1 by means of the lattice retention 14a, 14b. The displacement of material into the edge region 42 serves as a preliminary stage for forming
a ring flange.
The stamping die 54, shown in Figure 6 and having a bottom swage 4 8 and a double upper swage 50, 52, serves, in succession, first for stamping away the edge 58 and second for stamping a circular disc 56 out of the bottom region 57 of the blank 12c, the said bottom region forming the flange side. After the circular disc 56 has been stamped out, a radially inward-projecting flange neck 59 remains on the bottom region 57.
The double upper swage 50, 52 can be designed as a follow-on die, or there can be upper swages capable of being actuated separately from one another.
The blank 12c is separated from the steel strip 10 by stamping away the edge 58. The stamping out of the circular disc 56, which takes place from the web side, serves for the rough shaping of the ring inside diameter.
Up to this step of the method, the blank 12c was connected to the steel strip 10, shown in Figure 1, by means of the lattice retention 14a, 14b. The retention of the blank disc 12 on the steel strip 10 served, in each step of the method, for advancing it to the following workstation in each case.
Figure 7 shows, in an enlarged representation, a detail of the cut edge 60 after the edge 58 has been stamped away.
The embossing and deep-drawing die 68, shown in Figure 8 and having a bottom swage 62, an upper core swage 64 and an upper ring swage 66, serves, on the blank 12d, for embossing or smoothing the non-functional cut edge 6 0 (Figures 7 and 9) , for tapering the outside diameter of the web region from 3 0a (Figure 6) to 3 0b (Figure 8) by deep-drawing and for preshaping the flange
region 70. Moreover, the web region 30b is upset during this operation.
The bottom swage 62 has an annular depression 71 for receiving and preshaping the flange region 70. The flange region 70 of the blank 12d consists of the racially inward-projecting flange neck 59 and of a radically outward-projecting flange neck 73.
The upper core swage 64 serves essentially for holding the blank 12d on the bottom swage 62 and for fixing its inside diameter. An annular embossing and drawing edge 66a, arranged on the inner edge of the upper ring swage 66 according to Figure 9, serves both for embossing or smoothing the cut edge 60 of the blank 12d and for tapering its outside diameter.
A controlled flow of material from the web region 30b into the flange region 70 takes place as a result of the embossing and deep-drawing operation. In this case, the length of the web region 3 0b decreases. The compression of the material in the flange region 70, which the flow of material entails, is particularly advantageous, the flange region thereby being consolidated. As a result of the reduction in diameter of the web region 3 0b, the material in the latter can likewise be compressed.
Figure 9, in three successive individual diagrams, illustrates the continuous embossing and deep-drawing operation, during which the upper ring swage 66 is moved in the direction of the arrow 74.
The die 76, shown in section in Figure 10, has a bottom swage 78, an upper core swage 80 and an upper ring swage 82. It serves essentially for the final shaping of the functional faces of the flanged ring 84.
The T-shaped profile of the flanged ring 84 is
formed by a web 86 and a flange 88. In this case, the flange 88 is shaped out of the flange region 70 by extrusion and, at the same time, is rounded both on its inside and on its outside.
The flattened top side of the flange 88 is the side which faces downwards in the drawings, since, during the shaping method, the flange 88 of the flanged ring faces downwards, in contrast to its installed position.
During the process according to Figure 10, convexly shaped functional profiles between the web region 3 0b and the flange top side are imparted to the flange necks 72, 73a.
After the shaping process, the flanged ring is hardened or surface-hardened.
The shaping method according to the invention is suitable for flanged rings of different sizes and makes it possible to achieve considerable savings of material and cost. The flanged rings produced in this way can be used instead of flanged rings lathe-turned from solid material.
The spinning or twisting ring, likewise according to the invention, which is produced without cutting and completely by cold forming and which has a T-profile comprising a web and a flange, for example according to Figure 11, differs from the rings produced by cutting, on the one hand, in that the material of the web merges into the flange virtually continuously over the full cross-section of the said web. This can be ascertained from the run of the fibres, at least before heat treatment, such as takes place, for example, during hardening. Such a ring having a solid wall thus differs not only from the rings which are produced, for example, by lathe-turning
and in which fibres are cut, but also from the rings which are likewise produced without cutting and in which the flange has been shaped by bending steps. Reference may be made, here, to GB Patent Specification 692,399.
In order to produce a flanged ring according to the invention having a solid wall, as a rule steel strip of deep-draw able quality is taken as a starting point, deep-drawing forming being followed by upsetting and compression molding steps, by means of which the flange is formed. After shaping, such a ring is finished by casehardening and polishing.
A flanged ring having a solid wall, a so-called solid-material ring, which is manufactured completely by cold forming (Figure 11) , always, that is to say even when strip stock or sheet metal is taken as a starting point, has a clearly defined structure which can be ascertained in the hardened state. This can be seen from relatively widely differing grain sizes having an advantageous size distribution, in particular in the flange cross-section. The cross-sectional zones near the surface have a relatively fine grain in comparison with the flange core, where coarse grain is usually found throughout . This also makes it possible to achieve, on the flange surface, a higher Brinell hardness which is beneficial to the useful life of the ring. It may be stated, in general, that the grain size in the flange (88) decreases by at least 20% from the inside (90) towards the surface (92) and towards the web (86). As a rule, the average size difference is about the factor 2 or greater.
The above-explained advantages of the product of the method according to the invention likewise apply to
the ring according to Figure 11.
1. Method for shaping a spinning or twisting ring
having a T-shaped profile which is formed by a web (86)
and a flange (88) , characterized in that a blank disc
(12) is stamped out from steel strip (10) , the blank disc
(12) is deep-drawn in the shape of a cup to form an
annular web region (30, 30a) and a bottom region (57), a
ring having a radially inward-projecting flange neck (59)
is formed on the bottom region (57) by stamping out a
circular disc (56) centrically, and, by upsetting, the
bottom region (57) remaining on the web region (30, 30a)
is shaped to form a flattened flange top side and a
radially outward-projecting flange neck (73) is formed,
material being displaced into the flange region (70) both
out of the bottom region (57), before the circular disc
(56) is stamped out, and out of the web region (30, 30a) .
2. Method according to Claim 1, characterized in that the circular disc (56) is stamped out from the web side.
3. Method according to Claim 1 or 2, characterized in that a central hump (16) is formed on the blank disc (12) by deep-drawing and, after deep-drawing in the shape of a cup, at least the hump material in the bottom region
(57) Is displaced radically outwards into the flange
region (70, 73) by cold extrusion.
4. Method according to Claim 2 or 3, characterized in that web material is supplied to the flange region (70, 73) by upsetting the web region (30b) in the axial direction.
5. Method according to one of the preceding claims, characterized in that convexly shaped functional profiles
are imparted to the flange necks (72, 73) between the web region (30b) and flange top side by extrusion.
6. Method according to one of the preceding claims, characterized in that the diameter of the web region (3 0b) is tapered below the flange neck (70, 73) by drawing and ironing.
7. Method according to one of the preceding claims, characterized in that the blank (12, 12a, 12b), connected to the steel strip (10) by lattice stamping (14a, 14b) , is transported further over several operations by the advance of the steel strip (10).
8. Method for producing a spinning or twisting ring which is shaped according to one of the preceding claims, characterized in that the shaped spinning or twisting ring is hardened.
(9. Spinning or twisting ring, shaped by the method according to one of Claims 1 to 7.
10. Spinning or twisting ring, produced by the method according to Claim 8.
11. Spinning or twisting ring having a T-profile, obtainable by a method according to one of Claims 1 to 9, comprising a web (86) and a flange (88), characterized in that the material of the web merges into the flange virtually continuously over the full cross-section of the said web.
Spinning or twisting ring having a T-profile,
comprising a web (86) and a flange (88) , characterized in that the average grain size in the flange decreases by at least 20% from the inside towards the surface. 13. Spinning or twisting ring having a T-profile, with a web and with a flange adjoining the latter, the flange having a solid wall, the material of the web
merging virtually continuously into the flange over the full cross-section of the said web, and the average grain size in the flange decreasing by at least 20% from its inside towards the surface,
|Indian Patent Application Number||2362/MAS/1996|
|PG Journal Number||26/2007|
|Date of Filing||26-Dec-1996|
|Name of Patentee||M/S. BRACKER AG|
|Applicant Address||OBERMATTSTRASSE 65, CH-8330 PFAFFIKON|
|PCT International Classification Number||B21D53/16|
|PCT International Application Number||N/A|
|PCT International Filing date|